Chapter 39 Ports Pathophysiology

In a person with fluid volume deficit, there is a dehydration of brain and nerve cells. What can occur if fluid volume deficit is corrected too rapidly?

Cerebral edema occurs with potentially severe neurologic impairment. When this occurs, water moves into the brain cells, causing cerebral edema and potentially severe neurologic impairment. The other cells are not correct.

Which of the following is an anion?

Chloride The ions found in body fluids carry one charge (i.e., monovalent ion) or two charges (i.e., divalent ion). Negatively charged ions are called anions. Chlorine is a negatively charged ion, or anion.

A client develops interstitial edema as a result of decreased:

Colloidal osmotic pressure Edema can be defined as palpable swelling produced by an increased interstitial fluid volume. The physiologic mechanisms that contribute to edema formation include factors that (1) increase capillary filtration (hydrostatic) pressure, (2) decrease the capillary colloid osmotic pressure, (3) increase capillary permeability, or (4) produce obstruction to lymph flow.

A community health nurse who is attending a marathon recognizes which of the following types of hypotonic hyponatremia is likely when a patient reports muscle weakness, cramping, and general fatigue in spite of adequate water hydration during the run?

Hypovolemic Hypovolemic hypotonic hyponatremia develops when water, rather than electrolyte-containing liquids, is used to replace fluids lost in sweating. This may also be caused by gastrointestinal sodium loss caused by frequent irrigations with distilled water as well as by adrenal insufficiency. Hypervolemic problems are caused by excess water. The terms "euvolemic" and "normovolemic" are synonymous.

The nurse knows that magnesium is an important component of which of the following processes that are integral to the maintenance of homeostasis?

• Cellular energy metabolism • Function of the sodium-potassium pump • Nerve conduction • Cell membrane function

Which of the following interventions is a priority for the nurse when caring for a patient with hypokalemia?

Initiating cardiac monitoring Imbalances of potassium levels have potentially fatal cardiac implications, a fact that necessitates frequent electrocardiography or cardiac monitoring. This supersedes the importance of fluid balance monitoring, ABGs, or hemoglobin levels.

A female client with a history of chronic renal failure has a total serum calcium level of 7.9 mg/dL. While performing an assessment, the nurse should focus on which of the following clinical manifestations associated with this calcium level?

Intermittent muscle spasms and complaints of numbness around her mouth Spasms and numbness are characteristic of hypocalcemia. Respiratory effects, tachycardia, and diaphoresis are not associated with low calcium levels, whereas decreased level of consciousness can be indicative of hypercalcemia.

Lymph fluid arises directly from which one of the following spaces?

Interstitial The lymphatic system represents an accessory route whereby fluid from the interstitial spaces can return to circulation. More important, the lymphatic system provides a means for removing plasma proteins and osmotically active particulate matter from the tissue spaces, neither of which can be reabsorbed into the capillaries.

Pressure generated as water moves across a membrane is also known as which of the following?

Osmotic pressure Osmosis is the movement of water across a semipermeable membrane. As with particles, water diffuses down its concentration gradient, moving from the side of the membrane with the lesser number of particles and greater concentration of water to the side with the greater number of particles and lesser concentration of water. As water moves across the semipermeable membrane, it generates a pressure called osmotic pressure.

Body weight consists of which of the following percentages of body water?

60%

A client tells the nurse that the client has been taking Alka-Seltzer (bicarbonate—antacid) four times a day for the past 2 weeks for an upset stomach. Upon assessment of the client, the nurse notes hyperactive reflexes, tetany, and mental confusion. Arterial blood gases reveal pH 7.55; serum HCO3− 37. The nurse suspects the client may be experiencing:

Metabolic alkalosis Metabolic alkalosis is characterized by a serum pH greater than 7.45; serum HCO3− greater than 29 mEq/L; and a base excess greater than 3.0. Transient or acute alkalosis is common during or immediately following excess oral ingestion of bicarbonate antacids. Respiratory acidosis as well as metabolic acidosis would have a decrease in pH. Respiratory alkalosis would have an increase in pH and a HCO3− less than 24 mEq/L.

A nurse is caring for a patient with a low sodium level and increased water retention. Hematocrit and blood urea nitrogen levels are decreased, urine osmolality is high, and serum osmolality is low. A chest x-ray shows a possible lung mass. Based on these findings, which of the following problems could the patient be diagnosed with?

Syndrome of inappropriate antidiuretic hormone (ADH) The syndrome of inappropriate ADH (SIADH) results from a failure of the negative feedback system that regulates the release and inhibition of ADH. In people with this syndrome, ADH secretion continues even when serum osmolality is decreased, causing marked water retention and dilutional hyponatremia. SIADH may occur as a transient condition, as in a stress situation, or, more commonly, as a chronic condition, resulting from disorders such as lung or brain tumors. Tumors, particularly bronchogenic carcinomas and cancers of the lymphoid tissue, prostate, and pancreas are known to produce and release ADH independent of normal hypothalamic control mechanisms. The manifestations of SIADH are those of dilutional hyponatremia. Urine osmolality is high and serum osmolality is low. Urine output decreases despite adequate or increased fluid intake. Hematocrit and the plasma sodium and blood urea nitrogen levels are all decreased because of the expansion of the extracellular fluid volume.

The nurse is assessing a client with fluid volume excess. The nurse anticipates the client would manifest:

Weight gain Isotonic fluid volume excess is manifested by an increase in interstitial and vascular fluids and is characterized by weight gain over a short period of time. As vascular volume increases, central venous pressure increases, leading to distended neck veins, slow-emptying peripheral veins, a full and bounding pulse, and an increase in central venous pressure. Decreased blood pressure as well as a weak, rapid pulse reflect volume deficit. BUN and hematocrit may decrease as a result of dilution due to expansion of the plasma volume.