ABSITE

How much weight loss following gastric sleeve?

5 year weight loss is approximately 60% of excess body weight

Gallbladder hydrops

A hydrops of the gallbladder is a distended gallbladder secondary to chronic obstruction of the cystic duct by impaction with a gallstone. Over time, the gallbladder becomes filled with watery mucoid material. The bile gets absorbed, but the gallbladder epithelium continues to secrete mucus. The gallbladder becomes massively dilated and enlarged without infection secondary to prolonged obstruction of the cystic duct. This condition can also occur secondary to fasting and dehydration. In patients with hydrops of the gallbladder, the gallbladder is tense and distended, making it difficult to grasp and easy to tear. In these patients, retraction of the fundus is difficult, and exposure of Calot's triangle is unsatisfactory. This problem is best-managed by aspirating the contents of the gallbladder either percutaneously with a 14 or 16-gauge needle inserted into the fundus of the gallbladder under laparoscopic vision.

Whipple procedure

A pancreaticoduodenectomy (Whipple procedure) is generally indicated in patients with chronic pancreatitis with a nondilated duct. This procedure is reserved for patients with multiple cysts or calcifications in the head of the pancreas, obstructive symptoms, portal venous compression, or the possibility of malignancy.

Child-Turcotte-Pugh scoring system

A score of 5-6 is assigned to class A, 7-9 points is class B, and 10-15 points is class C. Overall surgical mortality rate is 10% for patients with class A cirrhosis, 30% for those with class B cirrhosis, and 75% to 80% for those with class C cirrhosis. Criticisms of the Child-Turcotte-Pugh include subjective variables (degree of ascites or encephalopathy), equal weighting of variables, and narrow score range. The score is composed of both qualitative and quantitative values and includes total bilirubin level, albumin level, international normalized ratio (INR) level, and degree of encephalopathy and ascites

Appendicits in pregnancy

Acute appendicitis is the most common nonobstetric indication for surgery in pregnancy. One in 1500 pregnancies will experience appendicitis. No one trimester is more affected than another. Prompt diagnosis and treatment is important, as non perforated appendicitis carries a 5% risk of fetal loss, while perforated appendicitis carries a 25% risk of fetal loss. Presentation varies compared with the classic presentation. The pain may be higher, due to cephalad displacement by the gravid uterus. Diagnosis is based upon imaging with ultrasound. If equivocal, MRI is the next best imaging study

Acute vs chronic aortic dissection

Acute dissection has traditionally been used to describe presentation within the first 2 weeks, whereas the term chronic is reserved for those patients presenting at more than 2 months after the initial event. The acute form of aortic dissection is often rapidly lethal, whereas those surviving the initial event go on to develop a chronic dissection with more protean manifestations. The DeBakey system differentiates patients based on the location and extent of aortic dissection. The advantage of this system is that four different groups of patients with different forms of aortic dissection emerge. The Stanford system, a functional classification system, states that all dissections that involve the ascending aorta are grouped together as type A, regardless of the position of the primary tear or the distal extent of the dissection. Clinically, type A dissections occur with an overall greater frequency. Stanford type B include dissections that originate in the descending thoracic and thoracoabdominal aorta regardless of any retrograde involvement of the arch.

Acute limb ischemia

Acute limb ischemia can be secondary to an embolic or thrombotic event. Embolic events are most commonly due to a cardiac source. Common causes of cardiac emboli include atrial fibrillation, myocardial infarction, ventricular aneurysm, and atrial myxoma. Other causes of emboli include proximal atherosclerosis or a paradoxical emboli that is initiated from a deep vein thrombosis. Arterial thrombosis occurs in patients with longstanding peripheral vascular disease who progress to complete occlusion. These patients will usually have bilateral claudication or rest pain prior to the event. Previous bypass grafts are at higher risk for thrombosis than an embolic event. If the etiology is unclear in an otherwise healthy patient, a CT scan should be performed to rule out a malignancy that may be causing a hypercoagulable state and thrombosis.

Recto-vaginal fistula

After confirming recurrent cancer is excluded from the differential diagnosis, a rigid proctoscopy would be the next best test. Post-radiation rectovaginal fistulae are associated with radiation damage to the rectum. The quality of the rectal tissue (fibrosis, friability, etc.) and its associated compliance will help determine what type of operation should be performed. It also may help to localize the fistula. A CT scan, transvaginal ultrasound, transrectal ultrasound, and barium enema cannot reliably assess the condition of the rectal tissue like endoscopy can

rectovaginal fistula

All of these tests can be used to assess for the presence of a rectovaginal fistula. Answer A: The methylene blue tampon test entails placing a tampon in the patient's vagina and then filling the rectum with methylene blue. Afterwards, the tampon is inspected for the presence of methylene blue. Answer B: The vagina "bubble" test involves filling the vagina with water while performing a rigid sigmoidoscopy on the patient. The vagina is inspected for the presence of air bubbles as the rectum is insufflated with air. Answers C & D: A CT with IV and rectal contrast as well as a barium enema can be performed to evaluate the passage of contrast into the vagina. These tests are not absolute however. A negative result does not automatically exclude a fistula, so clinical suspicion should guide further workup. Answer E: A CT with IV and rectal contrast as well as a barium or gastrograffin enema can be performed to evaluate the passage of contrast into the vagina. These tests are not absolute however. A negative result does not automatically exclude a fistula, so clinical suspicion should guide further workup. Bottom Line: Initial tests to assess for the presence of a rectovaginal fistula includes the methylene blue tampon test, vagina "bubble" test, CT with rectal contrast, and barium enema. The methylene blue tampon test seems to have the best sensitivity when done appropriately.

Pneumocytes

Answer A: Alveoli production continues until approximately 10 years of age. Answer B: Type II (Great Alveolar) cells secrete pulmonary surfactant between 24 and 28 weeks. Answer C: Alveoli production begins at 7 months gestation and continues until approximately 10 years of age. Answer D: The pores of Kohn are found in alveolar walls and allow communication between individual alveoli but do not play a significant role in carbon dioxide delivery. Answer E: Alveoli are squamous-lined sacs at the terminal ends of the respiratory tract that are the sites for gas exchange in the lung.

Acute limb ischemia

Answer A: Bilateral symptoms suggest thrombotic disease. Answer B: The most common cardiac source of emboli is due to atrial fibrillation. Answer C: Previous bypass grafts are more likely to have a thrombotic event. Answer D: Paradoxical emboli embolize through right to left shunts, especially patent foramen ovale. Bottom Line: Acute limb ischemia with an unknown etiology should have CT scan performed to rule out a malignancy.

Breast Screening

Biennial screening mammograms can begin starting at age 40, and annual screening mammograms should begin at age 50 or 10 years before the earliest diagnosed breast cancer in a relative. Screening should be yearly and continue as long as the patient is suitable for treatment if cancer is found

Bleeding Duodenal ulcer

Bleeding duodenal ulcers are usually a result of a posterior perforation into the gastroduodenal artery (GDA). This causes brisk bleeding that may present as bright red blood per rectum. Stable patients can have an endoscopy to attempt to clip or inject the vessel for hemostasis. If the patient rebleeds but remains stable, a second attempt at endoscopic therapy can be used. Any instance of hemodynamic instability or the need for over 4 units of blood is cause for operative intervention. For rapid control of bleeding, a longitudinal duodenotomy is made, and a figure of eight stitch applied above and below the bleeding vessel. A U stitch is then placed to ligate the transverse pancreatic branches that enter the GDA posteriorly. The duodenotomy is then usually closed transversely to complete the pyloroplasty. Oversewing of the vessel with a U stich to secure the GDA and transverse pancreatic artery is the procedure of choice for a bleeding duodenal ulcer in a hemodynamically unstable patient

Bloody diarrhea after endovascular AAA repair

Bloody diarrhea after any aortic case is concerning for bowel ischemia. The most likely inciting event for this process was coverage of the inferior mesenteric artery by the endograft. The first step in evaluation of bloody diarrhea in a stable patient is sigmoidoscopy as this watershed area is the most likely area for bowel ischemia. In patients who are hemodynamically unstable or have evidence of free air on x-ray signifying a perforated viscous, immediate exploration in the operating room is required. After aortic surgery bowel ischemia presents with bloody diarrhea and is typically in the sigmoid distribution. Sigmoidoscopy is necessary in stable patients, but in the presence of an acute abdomen or free air emergent operative intervention is required

Central pontine myelinolysis

Brain adaptations that reduce the risk of cerebral edema in chronic hyponatremia make the brain vulnerable to injury if the hyponatremia is too rapidly corrected. The neurologic manifestations associated with overly rapid correction have been called the osmotic demyelination syndrome (ODS, formerly called central pontine myelinolysis or CPM). This syndrome is caused by rapid correction of sodium deficit at greater than the appropriate rate of 0.5 mEq/L/hour. The risk is greatest for patients who have had a low sodium level for greater than 48 hours. Cerebral edema with brainstem herniation is seen with rapid correction of hypernatremia

Budd-Chiari syndrome

Budd-Chiari syndrome is caused by hepatic venous obstruction. The obstruction typically occurs at the level of the inferior vena cava, the hepatic veins, or the central veins within the liver. The etiology of this syndrome has a geographical variation. In the West, acute or chronic thrombosis and malignancy is the most common etiology. In Asia, membranous webs are the major cause of obstruction of the vena cava and hepatic veins. Answers A & B & C & D: The most common causes of Budd-Chiari syndrome in the WEST are hypercoagulable conditions associated with polycythemia vera, paroxysmal nocturnal hemoglobinuria, myeloproliferative disorders and conditions associated with high estrogen levels such as pregnancy and use of contraceptive pills.

Causes of pseudohyponatremia

Causes of pseudohyponatremia may lead to treatment that is not directed at the correction of sodium levels, such as in hyperglycemia, mannitol administration, or radiologic contrast medium.

ARDS

Decreased lung compliance in acute respiratory distress syndrome (ARDS) is due to alveolar flooding and collapse which leads to fewer alveoli to accommodate the tidal volume. Therefore, there is an increased stretch of the functional alveoli causing decreased compliance. Positive end-expiratory pressure (PEEP) is used in mechanically-ventilated patients with ARDS to improve oxygenation. In ARDS, three populations of alveoli can be distinguished. There are normal alveoli which are always inflated and engaging in gas exchange, flooded alveoli which can never, under any ventilatory regime, be used for gas exchange, and atelectatic or partially flooded alveoli that can be "recruited" to participate in gas exchange under certain ventilatory regimens. The recruitable alveoli represent a continuous population, some of which can be recruited with minimal PEEP, and others which can only be recruited with high levels of PEEP. Ventilation-perfusion (V/Q) mismatch is a cause of hypoxemia in pulmonary embolism among other pathologies but does not directly affect lung compliance and does not play a significant role in ARDS. While pulmonary edema can be manifest in ARDS and may contribute to hypoxemia, it does not decrease compliance. Increased peripheral oxygen utilization is the mechanism behind the decreased mixed venous oxygen saturation seen in sepsis

Sleeve gastrectomy

During the operation for sleeve gastrectomy, the greater curvature of the stomach is completely devascularized prior to being resected. Answer C: Blood supply to the gastric sleeve is received from the left and right gastric arteries as well as branches from the right gastroepiploic. Answer D: The posterior stomach does not require extensive dissection to mobilize in a patient who has not previously undergone a gastric procedure or had inflammation within the are of the lesser sac. Answer E: Larger staples (3.5mm) are needed to divide the stomach due to its thickness. The antrum is typically the thickest portion of the stomach so care must be taken when dividing this area. Smaller staple heights may strangulate the closure and increase risk for a leak.

Esophageal adenocarcinoma

Esophageal adenocarcinoma accounts for ~ 70% of esophageal cancer diagnoses in the United States. It is known to spread aggressively through the lymphatic channels. T1 tumors are divided into T1a and T1b, which signifies extent into the muscularis mucosae and submucosa respectively. T2 lesions spread into the muscularis propria, T3 lesions to the adventitia and T4 lesions invade surrounding structures. The likelihood of nodal invasion increases with the depth of the tumor. Upfront esophagectomy is indicated in patients with clinical T1N0M0 lesions and may be considered in those with clinical T2N0M0 lesions. Patients with T1a tumors or those who are poor surgical candidates may by considered for esophageal preservation using endoscopic resection techniques. Patients with nodal disease, T3 tumors, and select T4a tumors which are amenable to en bloc resection should receive neoadjuvant therapy prior to esophagectomy. There are no randomized trials which compare neoadjuvant chemotherapy to chemoradiotherapy, however chemoradiotherapy is often prefered due to improved rates of pathologic complete response. For patients who undergo upfront resection and are later found to have node positive, pT3, or pT4 tumors adjuvant chemoradiotherapy should be offered.

Blood donation reactions

Febrile transfusion reactions are the most common type of transfusion reaction. Febrile transfusion reactions are mediated by circulating cytokines to donor blood as well as cytokines within the stored donor blood. Anaphylaxis after transfusion is caused by recipient antibodies to donor IgA. Viral contamination of the blood rarely causes an immediate reaction. Urticaria is caused by recipient antibodies to donor plasma proteins. Donor antibodies to recipients WBC's causes a transfusion related acute lung injury.

Breast Cancer screening

For women of average risk, screening includes clinical breast examination, counseling to raise awareness of breast symptoms, screening mammography. - For women under age 40, screening is not warranted since the incidence of breast cancer is low and the performance characteristics of mammography are poor. - For women age 40 to 49, biennial mammography can be offered, but the decision should be individualized based on patient preferences and values. A woman may opt for screening if she has substantial concerns about breast cancer risk and accepts the possibility of a false-positive result or overdiagnosis and the resulting evaluation and treatment. Another woman may find that the frequency of false positives and overdiagnosis provides a compelling reason to defer screening. Although screening in the 40s appears favorable when considering the number of years of life potentially saved, for an average-risk woman, the number of breast cancer deaths prevented is relatively low. - For women age 50 to 74, annual mammography should be offered - For women age 75 and older, annual mammography should be offered if life expectancy is at least 10 years

GIST tumors

GIST tumors have the potential to behave malignantly and metastasize to distant organs. The most prominent indicator of this potential is mitotic figures and size of the tumor. It is recommended that tumors with > 5 mitoses per high power field and size > 5 cm be treated with Imatinib postoperatively to marginalize the malignant potential.

Ganglioneuromas

Ganglioneuromas are rare, benign, slow-growing tumors that arise from sympathetic ganglion cells. They are large encapsulated tumors, with an average size of 7 cm. They are more common in females younger than 20. They occur anywhere along the sympathetic chain, with common locations being the mediastinum, retroperitoneum, and adrenal glands. Histopathology reveals large, mature ganglion cells, axons, satellite cells, Schwann cells, and fibrous stroma. The Schwann cells are not neoplastic but associate with the neurons, though they do not elaborate any myelin. This separates them from schwannomas and neurofibromas, in which the Schwann cells are neoplastic. Immunohistochemistry shows strong staining of the ganglion cells for neurofilaments and strong staining of Schwann cells by S100.

Ureteral injuries

General principles for repair: 1. debridement; 2.tension free anastomosis and precise mucosal approximation and watertight closure (using interrupted 0-4 and 0-5 absorbable sutures); 3.internal ureteral stents, in most cases (Stenting is not mandatory, but typically used if the degree of transection approaches 50% of the ureteral circumference); 5. isolation of repair with omentum or fat in patients at high risk for infection; and 6. retroperitoneal drainage Options of repair: 1.Primary closure of partial transection of the ureter: If a partial transection of the ureter from a scalpel or scissors is seen during operation, often primary closure can be accomplished. 2. Primary uretrouretrostomy: Any complete transection can often be repaired by primary ureteroureterostomy. 3. Ureteral reimplantation and psoas hitch: Injuries of the pelvic ureter in which the distal ureteral segment is of poor quality or of insufficient length are best-managed by ureteral reimplantation 4.BOARI flap: The peritoneum is swept off the bladder dome, and a posteriorly based flap is created. The flap is folded back, a submucosal tunnel is developed in the flap and the ureteral reimplantation is completed. The flap is tubularized and closed in two layers. 5. Transureterouretrostomy: In cases of extensive pelvic ureteral loss where remaining proximal ureteral length is inadequate to allow reimplantation into the bladder, or concomitant significant ipsilateral pathology is present, a transureteroureterostomy may be considered. The recipient ureter is mobilized as little as possible to avoid any devascularization, and the injured ureter is brought under the mesentery above or below the inferior mesenteric artery, depending upon the degree of ureteral loss as well as the site selected for anastomosis Isolation and drainage: omental flaps the can be wrapped around the ureteral repair, providing physical isolation. Drains should be placed in the retro or extraperitoneal space.

CBD stone

Glucagon causes sphincter of Oddi relaxation and allows CBD stones to be flushed more easily. Intravenous glucagon administration is the next step in stone removal when flushing alone fails

IV Bisphosphonates

Hypercalcemia secondary to malignancies has shown good response to IV bisphosphonates

Treatment of symptomatic hypercalcemia

IV hydration and loop diuretics

What happens in a pre-operative patient who FEV1 is not adequate for lung surgery?

If the preoperative testing for a lobectomy suggests that the patient will not tolerate the procedure, the next step is to perform a ventilation/perfusion (V/Q) scan. This will show the distribution of ventilation and blood flow to each lobe of the lungs. If the desired lobe has a minimal contribution to the FEV1, then the patient can still likely tolerate a resection

CXR in penetrating trauma

In penetrating trauma, chest radiograph is indicated in wounds above the umbilicus or suspected thoracoabdominal injury. CT scans are only used if the patient is stable.

Ureteral injuries

Injuries to the ureter can be approached by dividing the ureter into thirds. Lower ureter injuries are commonly managed with reimplantation of the proximal ureter into the bladder. If the ureter has been ligated without transection, repair can be attempted with primary ureteroureterostomy over a stent. Answer A: Foley catheter placement and observation is not indicated due to morbidity from urinoma development. Answer B: Proximal ureteral injuries are typically managed with primary ureteroureterostomy. If there is significant ureteral loss, a segment of ileum may be used for ureteral replacement. Answer D: Autotransplantation is rarely performed for ureteral injury and is not advisable in trauma situations secondary to increased operative times. Answer E: Injuries to the midureter can be managed by primary ureteroureterostomy or transureteroureterostomy. Distal mobilization of the ureter provides additional length but it is important to avoid devascularizing the ureter. Bottom Line: Traumatic distal ureteral transaction is best managed with reimplantation of the proximal ureter into the bladder.

Bile acids

Intestinal bacteria further conjugate the primary bile acids into deoxycholic and lithocholic acids. Answer A: The bile acids are actively secreted into bile (choice E), and enter into the small intestine. Answer C: The bile acids are then actively reabsorbed in the terminal ileum and repeat the process via the enterohepatic circulation. Glucuronyl transferase is involved in the conjugation of bilirubin. Answer D: Their function is primarily for the digestion of fats. Within the hepatocyte, bile acids are conjugated with taurine and glycine (choice D). Answer E: Primary bile acids are formed in the liver from cholesterol (choice A). Bottom Line: Deoxycholic and lithocholic acids are secondary bile acids.

Chylous ascites

Intra-abdominal malignancies can impinge on lymphatic drainage if the base of the mesentery or cisterna chyli is involved.

Cause of isotonic hyponatremia

Isotonic hyponatremia can occur due to lab testing and is most commonly due to high blood triglyceride levels

Keloids

Keloids are characterized by wound healing rising above the original level of the skin and also extending beyond the original border of the wound. Steroids are first line therapy for keloids. Intralesional corticosteroid injection works by decreasing fibroblast proliferation, collagen glycosaminoglycan synthesis, and inflammation. These intralesional injections are more effective on early scars but will not cause the lesions to fully disappear. Complications may include atrophy of the skin as well as hypopigmentation, necrosis, and ulceration at injection sites.

Parastomal hernia

Laparoscopic parastomal hernia repair with mesh is now considered the treatment of choice by most surgeons. Stoma relocation is another option that is for patients who have other stoma problems, such as skin excoriation or suboptimal stoma construction. However, stoma relocation is a significantly more invasive procedure and subjects patients to a triple threat of hernia recurrence: (1) at the old stoma site, (2) at the new stoma site, and (3) at the laparotomy incision used to move the stoma. In this scenario, laparoscopic repair is avoided because stoma relocation would address the narrowing stoma, skin excoriation along with the hernia repair. Given that stoma relocation can lead to contaminated field, BIOLOGIC mesh is preferred

Lateral suture patch angioplasty

Lateral suture patch angioplasty is the appropriate choice. Repair of the artery is indicated after evaluation of the lumen of the artery. Patch angioplasty is utilized to decrease the chance of stenosis with primary repair. Answer A: Angioplasty and stent are not recommended at this time as further wire manipulation may worsen the damage, and the injured artery is exposed. Answer B: The patient has most likely suffered either a flow limiting dissection or formation of thrombus due to trauma. Exploration has yielded what appears to be a small injury to the vessel. Appropriate management would be exploration of the artery and repair. Embolectomy alone will not repair the damage to the vessel. Answer C: Placing foreign material in a traumatic wound is not indicated. Answer D: It is recommended to utilize contralateral saphenous vein for trauma. Bottom Line: Surgical repair is warranted in flow limiting injuries to the artery.

Varicose Veins

Ligation of the GSV at the saphenofemoral junction can control gravitational reflux while preserving the vein for subsequent arterial bypass. The GSV is largely preserved after proximal ligation, but reflux usually continues and hydrostatic forces are not controlled. Recurrent varicose veins are more frequent after saphenous ligation than after stripping. Varicosities happen more frequently after ligation and sclerotherapy than after stripping and sclerotherapy. Routine GSV stripping reduces the rate of recurrent varicosities and the need for re-operation for recurrent saphenofemoral incompetence

Puestow procedure

Longitudinal pancreaticojejunostomy (Puestow procedure) is indicated for patients with severe persistent pain from chronic pancreatitis which is refractory to medical therapy, repeated hospital admissions, and a dilated pancreatic duct > 8 mm in diameter. Contraindications include absence of pain, pancreatic cancer, cirrhosis, and cardiopulmonary comorbidities. The Puestow procedure involves creating a Roux-en-Y pancreaticojejunostomy. The pancreas is filleted to expose both the Ducts of Santorini and Wirsung, from neck to tail, and any stones encountered are removed. The Roux limb is then anastomosed to the pancreas. entails opening the pancreatic duct anteriorly along its length, medially to the level of the gastroduodenal artery, and laterally into the tail beyond all appreciable pancreatic duct strictures. The opened pancreatic duct is cleared entirely of stones and then sewn to a Roux-en-Y jejunal limb for drainage

MRSA gene that encodes altered PBP?

MRSA is becoming more and more prevalent in the community and hospital setting. It can affect almost any body fluid or cavity. Methicillin resistance results from the production of an altered penicillin-binding protein known as PBP2a, which has decreased affinity for most β-lactam antibiotics. PBP2a is encoded by the gene mecA.

Pilonidal disease

Many surgical techniques are available for the treatment of pilonidal disease. Midline excision can be followed by leaving the wound open, marsupialization of the dermis, primary closure or wound vacuum. Midline primary closure is associated with higher failure rate and higher recurrence rate compared to leaving the wound open or marsupialization of the dermis. Answer A: Postoperative antibiotics are not routinely indicated following pilonidal disease surgery. Answer B: Asymptomatic or a minimally draining sinus can be reasonably treated with local care and shaving the hair around the area at least weekly; however, recurrent abscess, painful disease or a chronically draining sinus are indications of surgery. Answer C: Many surgical techniques are available for pilonidal disease. Flaps are complex procedures that should be reserved for recurrent (stage V) or extensive disease that is extending beyond the navicular area (stage IV). Answer D: Following midline excision, most primarily closed wounds will dehisce secondary to lateral pressure created by sitting. Bottom Line: Midline excision of pilonidal disease with primary closure is associated with shorter healing time, but a higher complication rate than midline excision with marsupialization of the dermis or leaving the wound open.

Digestive disorders can be treated with what length fatty acid chain?

Medium chain triglycerides, not long chain triglycerides, are useful for those who cannot digest long chain fats, such as patients with malabsorption associated with pancreatic insufficiency, bile salt deficiency, short bowel syndrome, and bacterial overgrowth of the small bowel. Patients with pancreatic insufficiency cannot digest long chain triglycerides and may have steatorrhea.

Paronychia

Minor skin break down is the most common predisposing factor for acute paronychia; therefore, people with occupations that are associated with increased risk of such minor traumas have higher risk of developing acute paronychia. Staph aureus is the most common pathogen. Other possible organisms are streptococcus, enterococci and pseudomonas. Paronychia is the most common hand soft tissue infection. It represents 35% of all hand infections

Nonparametric data

Nonparametric data, is generally skewed and therefore does not fit a bell curve. Discrete data, such as that measured on a nominal or ordinal scale, consists of only a few possible values or categories and will not follow the normal distribution. Assessment of nonparametric data generally involves the use of contingency tables and significance testing uses methods such as the Mann-Whitney U (also known as Wilcoxon rank-sum) or Chi Square tests. Nonparametric data are generally discrete in nature and measured on nominal or ordinal scales. They are often skewed, do not fit the bell-shaped curve of normal data, and thus must be assessed using nonparametric methods such as the Mann-Whitney U or Chi Square tests.

Pancreatic pseudocyst

Pancreatic pseudocysts are encapsulated collections of fluid with high enzyme concentrations that arise from the pancreas. Pancreatic pseudocysts are associated with an epigastric mass and pain, mild fever, persistent serum amylase elevation. The walls of a pseudocyst are formed by inflammatory fibrosis of the peritoneal, mesenteric, and serosal membranes, which limits spread of the pancreatic juice as the lesion develops. The term pseudocyst denotes absence of an epithelial lining, whereas true cysts are lined by epithelium

esophageal replacement

Performing esophageal replacement is increasingly rare. First, there are improved methods of repairing the native esophagus in infants with esophageal atresia. Second, surgeons are adopting more aggressive approaches in antireflux surgery. Third, the introduction of childproof containers has resulted in decreased lye and caustic injuries to the esophagus. However, esophageal replacement is still being performed worldwide for a variety of indications. Overall, the posterior mediastinum provides the best route for esophageal substitutes during esophageal replacement

Plasmin

Plasmin is the active clotting inhibitor that acts to degrade fibrin and fibrinogen and disrupt the coagulation cascade. It circulates in an inactive form of plasminogen and is cleaved and activated by tissue plasminogen activators, namely urokinase and streptokinase. Plasminogen activator inhibitor acts to counteract the effects of plasmin.

Budd Chiari syndrome

Post-partum females with a pre-existing hypercoaguable disorder are at risk for fulminant Budd-Chiari syndrome, and treatment may only be achieved with liver transplant. The best diagnostic study is Doppler ultrasound . Characteristic findings include absent flow in the hepatic veins and inability to visualize connections between hepatic veins and the IVC. CT or MRI can be used as second-line studies if ultrasound does not confirm the diagnosis. Previously, venography was the gold-standard. However, due to its invasive nature, it has been surpassed by advances in Doppler ultrasound technology. Liver biopsy is not necessary for the diagnosis

post operative parotitis

Postoperative parotitis is a rare and serious staphylococcal infection of the parotid gland. It most commonly occurs in elderly, debilitated and malnourished patients. Dehydration and poor oral hygiene increases risk. It often occurs in the second week after surgery with prolonged intubation. Decreased secretion from the parotid glands leads to infected secretions within the gland. Staphylococci and gram negative bacteria from the oral cavity are the typical culprits. Inflammation leads to duct obstruction and abscess formation. Signs and symptoms begin with pain at the angle of the jaw that progresses to fever, elevated leukocytosis, edema and erythema overlying the parotid. Adequate fluid intake and good oral hygiene are important for prophylaxis. When signs and symptoms appear fluid from the Stensen duct can be cultured. Treatment should be started with vancomycin, warm packs and mouth irrigation. Progression despite these measures warrants surgical drainage

Post Transplant Tumors

Skin cancers are the most common malignancies following organ transplantation. They are usually located on sun-exposed areas. Squamous and basal cell carcinomas are the most frequent types. These malignancies have a higher likelihood to metastasize in this patient population. Treatment is the same as for non-transplant patients. Other malignancies are found to occur at increased rates in transplant recipients compared to the general population.

Ulcerative colitis

Smoking is protective ironically

Pancreatic enzymes

Some of the pancreatic digestive enzymes are synthesized and secreted in their active forms without the need for an activation step (e.g., amylase, lipase, ribonuclease). Lipase does require colipase to function properly. Answers B & C & D: The endopeptidases, which include trypsin, chymotrypsin, and elastase act on peptide bonds at the interior of the protein molecule, producing peptides that are substrates for the exopeptidases (carboxypeptidases), which serially remove a single amino acid from the carboxyl end of the peptide. Answer E: Most of the digestive enzymes are synthesized and secreted by acinar cells as inactive proenzymes or zymogens that, in health, are activated only after they reach the duodenum where enterokinase activates trypsinogen and the trypsin catalyses the activation of the other zymogens.

Rectus sheath hematoma

Specific treatment of a rectus sheath hematoma depends on the hemorrhage severity. Stable, unilateral hematomas may be observed without intervention. If small, the hematoma can even be observed without hospitalization. If there is concern for hematoma enlargement, active bleeding, or clinical deterioration, then first line therapy includes resuscitation and angiographic embolization. Hemoglobin and hematocrit should be monitored with transfusion as needed. Coagulation factor replacements should be considered with patients taking vitamin K antagonists. Surgical intervention and wound exploration is rare.

Anti-reflux therapy

Successful outcome after antireflux surgery is defined by two objectives: the achievement of long-term relief of reflux symptoms and the absence of complications or complaints after the operation. Factors that predict successful outcome following antireflux surgery are (i) the presence of typical symptoms of GERD, (ii) an abnormal score on 24-hour esophageal pH monitoring; and (iii.) symptomatic improvement in response to acid suppression therapy prior to surgery. Studies have shown that patients with typical symptoms, in comparison to those with atypical symptoms, have a better response to fundoplication. A 10-year follow-up study reported 85% of patients with typical symptoms had a successful outcome after Nissen fundoplication, compared to only 41% with atypical symptoms. Patients who experience exaggerated symptoms when supine rather than standing tend to have better outcomes after fundoplication as well. In the supine position, transient lower esophageal relaxation (TLSR) periods increase. Studies have shown that fundoplication reduces TLSR frequency by 50% and thus decrease reflux events

Succinylcholine

Succinylcholine (given as part of rapid sequence intubation) leads to hyperkalemia in spinal cord injured patients, as well as burn patients, and should be avoided. This leads to a wide complex tachycardia, torsade de pointes, and cardiac arrest. Succinylcholine is a ultrashort acting neuromuscular blocking agent (NMBA) with the most rapid onset of action. It is the only depolarizing NMBA in clinical use. The most lethal adverse effect of succinylcholine is hyperkalemia. Although a modest increase in the serum potassium level (0.5 mEq/L) occurs in most patients following the administration of succinylcholine, more profound hyperkalemia may occur in various comorbid features, including patients with burns, massive tissue trauma, upper and lower motor neuron lesions, and extensive skeletal muscle denervation. Extrajunctional receptors are synthesized in these states, and plasma levels of potassium can increase significantly following the administration of succinylcholine as activation of these receptors results in the opening of ion channels and the release of intracellular potassium.

Colon cancer staging

T = Tumor grade for the primary tumor. T1: Tumor invades submucosa, T2: Tumor invades muscularis propria, T3: Tumor invades through the muscularis propria into subserosa, T4a: Tumor penetrates to the surface of the visceral peritoneum, T4b: Tumor directly invades or is adherent to other organs or structures. N= Regional Lymph Node. N1: Metastasis in 1-3 regional lymph nodes (Subdivided in groups: N1a: Metastasis in one regional lymph node, N1b: Metastasis in 2-3 regional lymph nodes, N1c: Tumor deposits in the subserosa, mesentery, or non-peritonealized pericolic or perirectal tissues without regional nodal metastasis) N2: Metastasis in four or more regional lymph nodes (N2a: Metastasis in 4-6 regional lymph nodes, N2b: Metastasis in > 7 regional lymph nodes). M = Distant metastasis. M1: Distant metastasis (M1a: Metastasis confined to one organ or site (liver, lung, ovary, non-regional node), M1b: Metastases in more than on organ/site or the peritoneum

T-Tube s/p cholecystectomy

T-tubes are commonly inserted whenever there is a concern for retained gallstones after a CBD exploration to decompress the biliary tree. Usually a T-tube cholangiography is done 2 weeks post-operatively to evaluate any retained stones and for possible removal of the T-tube. A minimum of 4-6 weeks should pass before any instrumentation is performed to allow for the tract to mature.

Breast cancer in males

Tamoxifen confers a survival benefit for males with hormone receptor positive breast cancer. Orchiectomy is a second line hormonal manipulation in males with estrogen receptor positive, metastatic breast cancer. In the above case orchiectomy is not indicated because the patient does not have evidence of metastatic disease

Berger procedure

The Berger procedure entails resection of the pancreatic head with preservation of the duodenum, requiring a sleeve of pancreatic head tissue to remain behind in order to preserve the vasculature. It is technically more difficult than a Whipple procedure, and is uncommonly performed.

frey procedure

The Frey procedure involves subtotal resection of the head of the pancreas and drainage via pancreaticojejunostomy. It is best used in patients with ductal dilatation localized to the head and body of the

Milan Criteria

The Milan criteria were developed to identify patients with hepatocellular cancer who would be good candidates for a liver transplant. The criteria includes: - A single lesion less than 5 cm - Up to three lesions, each less than 3 cm - No extra-hepatic metastatic disease or major vessel involvement Liver transplant is the gold standard for patients with Child-Pugh B/C cirrhosis and limited hepatic reserve

Advantages of robotic surgery

The Robotic surgical system provides seven degrees of motion in comparison to four degrees of motion with the laparoscopic surgical system. The degrees of motion in both laparoscopic and robotic systems are 1) Up and down 2) forward and back 3) Right and left 4) Grip. The degrees of motion that are exclusive to robotic systems are 1) Wrist Yaw 2) Wrist pitch 3) Wrist roll. The elimination of hand tremors is a benefit of both laparoscopy and robotics. Robotic surgery also provides a high definition 3-D view.

Inflammatory breast cancer

The characteristic clinical findings which define the syndrome of inflammatory breast cancer are the result of infiltration and obstruction of dermal lymphatics by tumor cells. The skin involvement of inflammatory breast cancer makes this a T4 lesion, and therefore Stage IIIa, a locally advanced cancer. Skin biopsy may reveal tumor cells and lymphocytes in the dermal lymphatics, but absence of these findings are not sufficient evidence to exclude the diagnosis of inflammatory breast cancer

Ureteral stents

The correct answer is: B There have been many debates, especially with the advent of lighted ureteral stents, on their overall benefit. Preoperative stenting has the main benefit of helping to identify an injury once it occurs. Ureteral stents have not been definitively shown to prevent injuries, but this could change as more studies are done with new lighted stents. Stents are never used as the sole treatment for ureteral injuries. Answer A: Ureteral stents do not prevent ureteral injuries but help to identify them when they happen. Answer C: There are a few different ways to repair the ureter over a stent. The stent is NOT the only modality.

Mastitis

The differential diagnosis in a breastfeeding patient includes mastitis, abscess, or inflammatory breast cancer. If the patient fails antibiotic treatment, a biopsy be warranted. Staphylococcus aureus and Streptococcus species are common causes of an infected breast. Breast abscesses present with tenderness, erythema, and hyperthermia. These abscesses are related to lactation and occur within the first few weeks of breastfeeding. Preoperative ultrasonography is effective in delineating the required extent of the drainage procedure, which is best accomplished via circumareolar incisions or incisions paralleling Langer's lines. Superficial infections should be treated with local wound care, including application of warm compresses, and the administration of antibiotics (penicillins or cephalosporins). Given that the findings are consistent with superficial infectious mastitis during breast-feeding without fluctuation and low risk for breast cancer, it is ideal to try antibiotics.

Peri-operative diabetes control

The doses of insulin and other hypoglycemic drugs need to be titrated during the perioperative period. The oral hypoglycemic agents are withheld on the day of surgery and resumed after the surgery except Metformin. If there is altered renal action, then Metformin has to be withheld until the renal function stabilizes due to the risk of lactic acidosis. During this period hyperglycemia is managed with a short-acting insulin preparation based on blood glucose monitoring. Rapid and short-acting insulin is withheld when the patient is NPO and covered based on blood glucose monitoring. Intermediate and long-acting insulin is given at the normal dose the night before surgery. If there is a morning dose, then half the normal dose on the morning is given. Some patients use insulin pumps for glucose management. The pumps have variable delivery rate based on endogenous insulin production. On the day of surgery, the patient is managed with basal insulin infusion and the pump is used to correct the glucose level as it is measured.

Bile Salts

The entero-hepatic circulation is the secretion of bile salts by the liver into the intestine, followed by absorption by the ileum, and return of the bile salts to the liver via the portal vein. The entero-hepatic circulation is not a primary source of bilirubin. Cholic acid and chenodeoxycholic acid are the primary bile acids. They are conjugated with either taurine or glycine and function to digest fats and oils. Conjugated bile acids are not a source of bilirubin.

Steps for gastric sleeve

The essential steps for completion of sleeve gastrectomy include: 1. Devascularization of the greater curve of the stomach 2. Insertion of a bougie (34 French - 40 French) or endoscope to size the gastric sleeve 3. Transection of the stomach starting at a location 2 cm to 6 cm proximal to the pylorus 4. Specimen extraction.

Expected weight loss after sleeve gastrectomy

The expected excess weight loss after 2 years following sleeve gastrectomy is approximately 60%. Percentage excess weight loss (EWL) is calculated using the formula: %EWL = weight loss (kg)/excess weight (kg), with excess weight being the difference between actual weight and ideal weight. Since this patient weighs 150 kg and his ideal weight is 75 kg, his excess weight is 75 kg. He is expected to lose approximately 60% of this excess weight or approximately 45 kg.

LES tone

The hormones gastrin and motilin have been shown to increase LES pressure.

Surgical Management of Intussusception

The intussusceptum is delivered through a transverse incision in the right side of the abdomen and reduced by squeezing the mass retrograde from distal to proximal until completely reduced. Warm lap pads may be placed over the bowel and a period of observation may be warranted in cases of questionable bowel viability. Adhesive bands around the ileocecal junction are divided, and an appendectomy is then performed. The recurrence rates are very low after surgical reduction. Invariably, the lymphoid tissue within the ileocecal valve region is thickened, edematous and may be mistaken for a tumor within the small bowel.

LES tone

The lower esophageal sphincter (LES) is the most critical antireflux defense mechanism and has intrinsic myogenic tone modulated by neural and hormonal mechanisms. Alpha-adrenergic neurotransmitters or beta-blockers stimulate the LES, and alpha blockers and beta stimulants decrease its pressure. The hormones gastrin and motilin have been shown to increase LES pressure; and cholecystokinin, estrogen, glucagon, progesterone, somatostatin, and secretin decrease LES pressure.

Chronic pancreatitis

The medical treatment of chronic or recurrent pain in chronic pancreatitis requires the use of analgesics, a cessation of alcohol use, oral enzyme therapy, and the selective use of antisecretory therapy. Antisecretory therapy includes somatostatin or somatostatin analogue (octreotide acetate) administration, which has been shown to inhibit pancreatic exocrine secretion and CCK release. Although different forms of antacids was not effective in controlling the patient's pain as stated in the previous question, PPI may assist in preventing inactivation of pancreatic enzyme when used in conjunction.

diastasis recti

The midline epigastrum (linea alba) is a physiologic area of weakness in the abdomen. Two main processes can occur in this area. First, is diastasis recti. The second are abdominal wall hernias. Rectus abdominus diastasis occurs when the rectus muscles have separated and when the muscles contract, as in a sit-up, the bulge appears. This is classic in postpartum women or patients after weight loss. Obesity is a risk factor. This is not a true hernia, though it has the appearance of one. Treatment is with abdominal wall strengthening and weight loss. Operative repair, though typically not required, can be performed and typically involves a vertical plication

Appendiceal cancer

The most common tumor of the appendix is carcinoid, but not all appendiceal carcinoids are malignant. Malignant features include size over 1-2 cm, presence in lymph nodes, or invasion of tissues adjacent to the appendix. Adenocarcinomas are more common primary malignancies of the appendix than carcinoids. Even so, adenocarcinoma originating in the appendix is rare, and usually resembles colonic adenocarcinoma microscopically. The signet-ring cell carcinoma form carries a worse prognosis. Most mucinous tumors of the appendix are benign, mucinous cystadenomas. The rare malignant form, mucinous cystadenocarcinoma, is identified by invasion through the wall of the appendix or epithelial cells in mucus found in the peritoneum. Appendiceal tumors can present with peritoneal seeding, resulting in peritoneal carcinomatosis or pseudomyxoma peritonei. Gastrointestinal stromal tumors are rare tumors with malignant potential. Primary lymphomas can occur in the appendix. Breast cancer, colon cancer, and tumors of the female genital tract may metastasize to the appendix.

Lung Abscess

The patient has developed a lung abscess secondary to an episode of aspiration. Lung abscesses are more common on the right and present with an air-fluid level on imaging. Fungal infections and tuberculosis will not have an air-fluid level. The majority of patients can be treated with antibiotics alone. However, if medical management does not clear the infection after 8 weeks, surgery is indicated. Other surgical indications include large cavities over 4-6 cm, hemoptysis, and ruling out malignancy. Answer A: The left main stem bronchus is more angulated than the right. Therefore, aspiration contents prefer the right lung. Answer B: Bronchoscopy can help to identify the organism but will not be able to treat the abscess. Answer C: Lung abscesses rarely rupture. Answer E: This is the case if the patient is confirmed positive for TB. However, there is no information to suggest that in this question.

Chronic Crohn's disease

The patient has developed chronic Crohn's disease. Although he is responding to the treatments for his acute episodes, he should be started on medications to achieve remission. Long-term steroids have many side effects and are generally avoided when possible. Immune modulators such as Azathioprine and Infliximab are better utilized for long-term remission but take several weeks to become effective. Over 50% of all Crohn's patients will require surgery at some point during their disease course. Patients with chronic inflammatory bowel disease will need screening colonoscopies 8-10 years after diagnosis and then annually to ensure no dysplasia has developed.

Nitroprusside toxicity

The patient is exhibiting symptoms of cyanide toxicity secondary to the nitroprusside medication. These patients can have weakness and confusion and develop pulmonary edema. Thiocyanate levels can be checked to ensure the patient does not have a toxic level of cyanide. Antidotes for cyanide toxicity include amyl nitrite, sodium nitrite, and sodium thiosulfate.

Treatment of Hypervolemic hyponatremia

The patient now presents with acute, symptomatic, hypervolemic, hyponatremia due to excessive water intake. The appropriate treatment is correction of the sodium deficit with hypertonic saline. Sodium deficit is calculated based upon actual and desired sodium level and total body water. The appropriate rate of sodium correction in this setting is 0.5 mEq/L/hour.

Bilirubin

The primary source of bilirubin in the body is from breakdown of red blood cells. Whether due to aged cells or active hemolysis, hemoglobin is broken down into bilirubin and ultimately secreted into bile.

Anal Squamous cell carcinoma

The primary treatment for localized squamous cell carcinoma is chemoradiation, also known as the Nigro protocol, named after Norman Nigro in 1974. The protocol consists of 5-fluorouracil (5-FU), mitomycin-C, and preoperative radiation. Up to 30% of patients will have recurrence or have residual disease, and these patients are the ones who benefit from surgery. The surgical procedure for excision of a lesion in the anal canal should be an abdominoperineal resection (APR). Although there is some new evidence that recurrent disease can be treated with a 5-FU-based regimen, National Comprehensive Cancer Network guidelines still recommend APR for recurrent disease.

Sensory innervation of Larynx and epiglottis

The sensory nerve supply of the upper epiglottis is the glossopharyngeal nerve, which provides the sensory pathway of the gag reflex. The lower epiglottis and the laryngeal mucosa above the vocal cords is supplied by the internal branch of the superior laryngeal nerve, which contributes to the cough reflex. The sensory supply of the larynx below the vocal cords is via the recurrent laryngeal nerve. The recurrent laryngeal nerve also provides motor innervation to the intrinsic muscles of the larynx, except the cricothyroid muscles.

Thoracic duct

The thoracic duct is the main lymphatic channel for the abdomen and chest. Chylomicrons and long-chained fatty acids enter into this lymphatic system, whereas short and medium-chained fatty acids are transported in the portal system. It originates at the cisterna chyli at L1-L2 and courses superiorly through the aortic hiatus. It runs along right of midline until crossing to the left at T4-T5. The duct then empties in to the left subclavian vein at the junction with the internal jugular vein.

CBD exploration

There are multiple different extraction methods to allow for laparoscopic clearance of common bile duct (CBD) stones which include basket extraction using fluoroscopy, choledochoscopic basket extraction, and laparoscopic choledochochotomy with balloon sweep extraction. Laparoscopic choledochotomy is considered an advanced laparoscopic technique and should only be attempted if one is familiar with this technique. After this is completed, a T-tube should be left in place in a similar manner to an open procedure. Choledochoscopy is limited by the necessity for the cystic duct to be dilated up to 8 mm. Basket extraction using fluoroscopy is a skill that many surgeons are quite comfortable with given its similarities to angiography. However, if a surgeon is not familiar with these techniques and there are no other options available (either surgically or radiographically) to extract the stone, then converting to an open CBD exploration should be performed. Transcystic choledochotomy and stone retrieval usually entails making a transverse incision about halfway of the diameter of the cystic duct and inserting an endoscope to explore. In a pinch, a ureteroscope can be used if a choledochoscope is unavailable.

Pneumocytes

There are three major cell types in the alveolar wall (pneumocytes): Type I (Squamous Alveolar) cells that form the structure of an alveolar wall Type II (Great Alveolar) cells that secrete pulmonary surfactant to lower the surface tension of water and allows the membrane to separate, therefore increasing its capability to exchange gases. Surfactant forms an underlying aqueous protein-containing hypophase and an overlying phospholipid film. Macrophages that destroy foreign material, such as bacteria.

Lung Resection critical value

There is an array of pulmonary function tests that are used to determine if a patient can tolerate a lung resection. The most important of these values is the FEV1. If the predicted postoperative FEV1 is greater than 0.8 L, then the patient will likely tolerate the procedure. The recommended predicted postoperative FVC is greater than 1.5 L. The DLCO is a measure of the diffusion capacity of the lung. A procedure is contraindicated if the predicted postoperative value is less than 40%.

Li-Fraumeni syndrome

This family is presenting with a familial cancer known as Li-Fraumeni syndrome. This syndrome is characterized by the diagnosis of a soft tissue sarcoma before the age of 45, along with the diagnosis of any cancer in a first and second degree relative before 45 years old. The most common type of alternate cancers described are breast and brain neoplasms. The mutation associated with Li-Fraumeni syndrome is with the p53 gene and is inherited in an autosomal dominant pattern.

Surgical correction of a recto-vaginal fistula

This patient has adequate anal sphincter tone and good performance status. Therefore, resecting the diseased rectum and restoring continuity is reasonable. A good vascular pedicle should be placed between the vagina and the anastomosis to help decrease reformation of the fistula. In addition, some authors also advocate temporary fecal diversion. Answers A & D: For patients that had poor anal sphincter tone, restoring continuity would most likely result in fecal incontinence. If that were the case, an end colostomy with or without resection would then be appropriate. Answer B: Patient performance factors heavily impact the correct procedure. For a frail patient with poor performance factors that could not tolerate a major colonic resection, a loop sigmoid colostomy would be appropriate. Answer E: The fact that the patient's rectal mucosa is friable and fibrotic heavily impacts the potential surgical options. A mucosal advancement flap would most likely fail as the rectal tissue is not healthy and most likely has compromised blood flow due to the radiation damage. This repair would likely break down. Bottom Line: Radiation induced rectovaginal fistula patients with adequate anal sphincter tone and performance status should be offered resection and reanastomosis with a vascularized buttress.

.VAP treatment guidelines

This patient is concerning for development of ventilator-associated pneumonia (VAP). Emphasis on treatment of VAP is placed on rapid broad-spectrum escalation and de-escalation of antibiotics due to growing multi-drug resistance (MDR) pathogens in health care setting. Recent 2016 guidelines from Infectious Disease Society suggest the following empirical antibiotics regimen for VAP: Any of the following present, which increases the likelihood of MDR-VAP, should be treated with combination of 3 antibiotics (Zosyn/Cefepime/Ceftazidime/Imipinem/Meropenem/Aztreonam + Levofloxacin/Ciprofloxacin/Amikacin/Gentamicin/Tobramycin + Vancomycin/Linzeolid): - IV antibiotic use within previous 90 days - Septic shock at time of VAP - ARDS prior to VAP - More than 5 days of hospitalization prior to VAP - Acute renal replacement therapy prior to VAP If none of the above risk factors are present, then two drug therapy is sufficient (Zosyn/Cefepime/Ceftazidime/Levofloxacin/Ciprofloxacin/Imipenem/Meropenem/Aztreonam + Vanco/Linezolid), if risk factors for MRSA are present: - Treatment in a unit in which 10-20% S. aureus are methicillin-resistant - Treatment in a unit in which MRSA rate is unknown If none of the above risk factors for MDR-VAP are present AND no risk factors for MRSA are present then single monotherapy with Zosyn/Cefepime/Levofloxacin/Imipenem/Meropenem is sufficient.

Aortic dissection

Thoracic aortic dissection occurs when an intimal tear allows redirection of blood flow from the aorta (true lumen) through the intimal defect into the media of the aortic wall (false lumen). A dissection plane that separates the intima from the overlying adventitia forms within the media. Aortic dissection should always be considered in the setting of severe, unrelenting chest pain, which is present in most patients. The character of the pain is often described as "ripping" or "tearing." The pain is constant with greatest intensity at the onset. Patients usually have no previous episodes of similar pain, which often causes anxiety. Pain is usually located in the midsternum for ascending aortic dissection, while in the interscapular region for descending thoracic aortic dissection. Risk factors include primary hypertension, presence of aneurysmal disease of the aorta, or familial connective tissue disorders. The differential diagnosis of chest pain as a result of aortic dissection includes diagnoses such as myocardial ischemia, aortic aneurysm, acute aortic regurgitation, pericarditis, musculoskeletal pain, and pulmonary embolus. It is essential to consider aortic dissection in each case, as specific therapy (eg, thrombolytic therapy for acute myocardial infarction) may negatively impact the survivability of acute dissection.

Stone extraction

Transoral endoscopic retrograde cholangiography (ERCP) is not recommended since the patient's gastric pouch is a considerable distance from the patient's duodenum due to her Roux-en-Y bypass. However, it is possible to laparoscopically assist a successful ERCP by bringing the remnant stomach to the abdominal wall and allowing access by creating a gastrostomy. Percutaneous transhepatic cholangiography (PTC) with stone extraction is possible. Stone extraction through a previously placed T-tube remains the best and easiest option in this patient. If all else fails, an open common duct exploration is always a valid option.

Hyponatremia

Treatment of asymptomatic, euvolemic or hypervolemic hyponatremia is free water restriction and observation of sodium levels. Hypovolemic hyponatremia is treated with volume resuscitation with either lactated ringer's solution or normal saline solution. If the patient were symptomatic, treatment would be correction with hypertonic saline solution.

Undifferentiated spindle cell tumor (malignant fibrous histiocytoma of bone)

Undifferentiated spindle cell tumor (malignant fibrous histiocytoma of bone) is an uncommon tumor. The most common site of occurrence is the proximal tibia and distal metaphyses of the femur. It may also be found in the pelvis, humerus, and scapula. Radiographic features include loss of normal trabeculation and cortical destruction. Adjacent soft tissue invasion and mass formation may occur. MRI with contrast is the imaging study of choice. Pathology commonly shows high-grade lesions (> 90%) and a tumor showing fibroblasts in a whirling pattern with multinucleated giant cells, inflammatory cells, and foamy mononuclear giant cells. Neoadjuvant chemotherapy can be administered in which it can relieve pain and decrease local edema, contracture, and the size of the soft tissue tumor. Urgent surgical resection is indicated if at high risk for pathologic fracture. Surgical excision with wide margin is advised whether or not the patient receives neoadjuvant therapy. Amputation can normally be avoided.

Pancreatic pseudocyst

Usually located within pancreas or adjacent in lesser sac, CT scan is diagnostic test of choice. For cysts greater than 5 cm, treatment is usually recommended over expectant management, because most cysts can be promptly eliminated by percutaneous catheter drainage or surgical drainage into the stomach or intestine. Either duct may be dilated and in need of surgical drainage in conjunction with drainage of the pseudocyst.

VAP

VAP is defined as pneumonia (defined as new lung infiltrate plus clinical evidence of infectious origin of infiltrate including fever, purulent sputum or increased secretions, leukocytosis, and increasing oxygenation requirement) occurring >48 hours after endotracheal intubation. Patients with risk factors for multi-drug resistant pathogens should receive empiric antibiotic therapy consisting of drugs against gram-positive, B-lactam anti-pseudomonal, and non-B-lactam anti-pseudomonal.

intussusception

When the clinical index of suspicion for intussusception is high, hydrostatic reduction by enema using contrast or air is the diagnostic and therapeutic procedure of choice. Contraindications to this study include the presence of peritonitis or hemodynamic instability.

Neck Zones

Zone I is located from the clavicle to the cricoid. Injuries to this zone may involve lung apex, trachea, brachiocephalic or subclavian artery and veins, nerve roots and esophagus. Zone II is located from the cricoid to the angle of the mandible. Injury in this location may involve the carotid or vertebral arteries, the jugular veins, esophagus or trachea. Zone III is located from the angle of the mandible to the skull base. Injury to this zone may result in external or internal carotid injury, jugular injury, cranial nerve injury or hypopharyngeal injury. Those patients that are hemodynamically unstable require operative intervention, regardless of zone. Other indications for operative intervention include hard signs of vascular injury (bruit, thrill, expanding or pulsatile hematoma) or tracheal injury (subcutaneous air or bubbling from the wound).

most frequently used test to diagnose acute aortic dissection?

helical ct. Not aortography

Type A

include ascending aorta and anything else

what is transition point for type a vs type b aortic dissection

left subclavian artery