Inhalants, Gases, Weapons of Mass Destruction, Pesticides and Insecticides

Indications for HBO in CO exposures

(SMaLl Chest Pain) Syncope Metabolic acidosis Level >25% Chest pain or EKG changes Pregnancy with > 15%

Which respiratory irritant has the greatest solubility? A. Ammonia B. CO2 C. Hydrogen sulfide D. Methyl bromide E. Ozone

Answer A. Ammonia is a highly water soluble irritant gas approximately 90 grams per 100 ml of water (90 gm%) CO2 0.2 gm% Hydrogen sulfide 0.4 gm% Methyl bromide 2 gm% Ozone 0.001 gm%

What is the most common symptom of intermediate syndrome with respect to organophosphate (OP) toxicity? A. Proximal limb and cranial nerve palsies B. Mydriasis C. Bronchorrhea D. Ventricular dysrhythmias E. Vomiting and diarrhea

Answer A. Cranial nerve palsies and motor weakness (usually arms) are often the first sxs of intermediate syndrome. The following OPs can cause intermediate syndrome: metholate, malathion, diazinon, fenthion, parathion and methylparathion

Which can be an early symptom of nicotine toxicity? A. Pallor B. Hypotension C. Anemia D. Rash E. Atrial fibrillation

Answer A. Pallor can be seen in acute toxicity from vasoconstriction, also hypertension, tachycardia, and GI upset.

Reactive airway dysfunction syndrome (RADS) is unlikely after exposure to which toxic gas? A. Helium B. Chlorine C. Methylisocyanate D. Ammonia E. Capsaicin

Answer A. RADS is an "irritant-induced asthma" or a persistent asthma-like syndrome associated with acute exposure to a toxic gas. Virtually any irritating gas may produce RADS. Helium is a nonirritating simple asphyxiant NOT associated with RADS.

What is the primary objective of any hazmat control? A.Prevention of secondary contamination of responders B.Categorize the type of injury to victims C.Triage victims D.Establishing ABC E.Antidote administration

Answer A. Responders are of no help if they themselves become victims.

Which rodenticide is considered most lethal on a mg/kg basis? A. Phosphorus (elemental) B. Sodium fluoroacetamide C. Barium salts D. Thallium E. Zinc phosphide

Answer A. The order of decreasing LD 50 is: Phosphorus 1mg/kg Sodium fluoroacetamide 13-14 mg/kg Thallium 14 mg/kg Barium 20-30 mg/kg Zinc phosphide 40 mg/kg

Which rodenticide produces a fishy breath odor and black vomitus in overdose? A. Arsenic B. Zinc phosphide C. Methyl bromide D. Brodifacoum E. Vacor

Answer B. Both zinc and phosphine are released when zinc phosphide comes into contact with water and stomach acid. It is usually available in a 1% concentration and is water insoluble, heavy, gray, and a crystalline powder. Known for its fishy/garlic odor, it is used frequently in developing countries because it is effective and has low production costs. Phosphine, however, is the main contributor to the clinical sequelae seen after an exposure, including generalized cellular toxicity and necrosis of the GI tract, liver and kidneys. The patient's emesis has the potential for off-gassing. Toxicity occurs rapidly.

Which is true about irritant gases? A. Mixing sodium hypochlorites and any acid may generate chloramine gas B. Burning polyvinylchloride (PVC) plastic may liberate phosgene C. Silo-fillers disease is relate to excess exposure to sulfur dioxide D. Burning nitrocellulose (radiographic film) is expected to generate cyanide E. Inhalation of hydrogen fluoride does not produce systemic findings typical of dermal hydrofluoric (HF) acid poisoning

Answer B. Combustion of PVC may liberate nitrogen dioxide, phosgene, and cyanide as well as other toxic gases. Chloramine is a toxic byproduct of bleach and AMMONIA. Mixing bleach with any other acid liberates chlorine gas. Burning x ray film liberates nitrogen from the nitrocellulose. Silo fillers disease is caused by oxides of nitrogen which are generated by decomposing fertilizer/dirt. HF acid can produce systemic reactions regardless of route.

Which toxic gas is formed by combustion of plastics? A. Styrene B. Cyanide C. Sulfur dioxide D. Hydrogen fluoride E. Hydrogen sulfide

Answer B. Cyanide is produced from combustion of many nitrogen-containing products such as plastics, polyurethane, wool, silk, nylon, nitrocellulose, polyacrylonitriles, synthetic rubber and paper. High concentrations of cyanide have been reported in both fire survivors and fire fatalities. Also produced by combustion of plastics: hydrochloride, aldehydes, ammonia, oxides of nitrogen, phosgene, chlorine

Which is true about acetonitrile? A. Acetonitrile when ingested causes death within minutes B. It is biotransformed by the cytochrome P 450 system to cyanide C. Most reports of toxicity are occupational D. It is converted to cyanide by bugs in our GI tract E. It is extremely toxic regardless of metabolism

Answer B. It is relatively nontoxic. It is metabolized by the P 450 system to cyanide. Most often it is kids exposed to artificial nail remover that contains acetonitrile.

What mechanism best explains the reason for "sudden sniffing death"? A. Reperfusion injury B. Interference with K+ current C. Na channel blockade D. Simple asphyxiation E. Ca channel blockade

Answer B. It's thought that inhalants "sensitize the myocardium" by blocking the potassium current (QT interval) and prolonging repolarization. Sudden sniffing death can occur when a huffer/bagger/sniffer gets frightened by parents/police and a catecholamine surge (running) affects a sensitized myocardium causing a lethal dysrhythmia.

Influenza-like sxs (N/V, headache) in a patient with inhalation of paint remover may represent the delayed onset of what? A. Methanol toxicity B. CO toxicity C. Hepatotoxicity D. N-hexane toxicity E. Leukoencephalopathy

Answer B. Methylene chloride, most commonly found in paint removers and degreasers, is unique among the halogenated hydrocarbons in that it undergoes metabolism in the lover to carbon monoxide. In addition to acute CNS and cardiac sxs, inhalation of methylene chloride can be associated with delayed onset and prolonged duration of sxs of CO toxicity.

Clinical presentation after exposure to a highly water soluble irritant gas typically includes what? A. Acute lung injury (ALI) B. Conjunctival and oropharyngeal mucosal erythema C. Hypoxemia on ABG D. Symptom onset delayed for 24 hrs E. Improvement with nebulized 2% calcium gluconate

Answer B. Water soluble irritants typically produce rapid onset of upper airway irritation and prompt the exposed person to escape from the gas, limiting exposure. Sxs may progress for hrs but do not begin in a delayed fashion. Sxs develop in the eyes/nose/throat/mouth after exposure. ABG is normal because the lungs are not involved. Sxs may improve with Na HCO3 nebulizer but no with calcium gluconate.

What best characterizes the primary effect of excessive ingestion to Chlorphenoxy herbicides? A. Acute tubular necrosis and peripheral neuropathy B. GI upset and CNS depression C. Muscle pain and hypothermia D. Urticaria and wheezing E. Bradycardia and excess secretions

Answer B. When ingested in large amounts, Chlorphenoxy herbicides can cause oral/GI damage, CNS depression (paralysis and coma), inhibition of oxidative phosphorylation (causing fever), widespread muscle damage and rhabdomyolysis. After substantial dermal exposure, a mixed sensory-peripheral neuropathy has occurred after a latent period of time. Agent orange had chlorphenoxy included in its ingredients.

Which is a symptom of nicotine withdrawal? A. Diarrhea B. Depression C. Tachycardia D. Muscle relaxation E. Anorexia

Answer B. Withdrawal produces general dysphoria and antidepressants have been used in treating withdrawal symptoms.

Which is true regarding inorganic and organic rodenticides? A. All organic rodenticides are considered highly toxic B. All organic rodenticides are considered moderately toxic C. All inorganic rodenticides are considered highly toxic D. All inorganic rodenticides are either highly or moderately toxic E. Low toxicity rodenticides may be found in both organic and inorganic groups

Answer C. According to the Federal Insecticide, Fungicide, and Rodenticide Act - those rodenticides with a single dose of LD 50 (median lethal dose for 50% of test subjects) of less than 50mg/kg are considered highly toxic. All the inorganic rodenticides fall into this category.

Barotrauma (pneumothorax, pneumopericardium, pneumomediastinum) is associated with which drug of abuse? A. Benzylpiperazine (BZP) B. Barbiturates C. Marijuana D. Methylenedioxy methamphetamine (MDMA) E. Gamma hydroxybutyrate (GHB)

Answer C. Barotrauma results from dep inhalation and Valsalva maneuver that follows abuse of inhaled XB like coke and marijuana and from direct pressure injury resulting from high-pressure nitrous oxide containers. It is not common with ingested drugs of abuse.

A mass casualty event where victims collapse with respiratory failure is least consistent with exposure to what substance? A. Carfentanil B. Cyanogen chloride C. Lewisite D. Tabun E. Vx

Answer C. Carfentanil and cyanogen chloride cause sudden collapse. Mass casualty from lewisite should present with dermal, ocular, and respiratory tract sxs. The most severely poisoned lewisite victims can develop shock and respiratory failure in a delayed fashion. Lewisite is a vesicant, used in chemical warfare, smells like geraniums, causes immediate intense eye, skin (vesicles form and rupture) and resp sxs, treated with BAL (British Anti Lewisite) and rapid decontamination. This can be differentiated from sulfur mustard since that has a delayed onset and frequently can be missed by HCP - increasing exposure.

What symptom of OP toxicity is of the greatest life-threatening concern after acute exposure? A. Bronchorrhea B. Bradydysrhythmias C. Respiratory insufficiency D. Prolonged QTc E. Increased GI motility

Answer C. Excessive cholinergic stimulation resulting in depolarization of the neuromuscular junction can lead to effects to those of succinylcholine: paralysis and respiratory arrest.

Which is correct about Pyrethroids? A. They are extracted from geraniums B. They are active metabolites of piperonyl butoxide C. Mammals demonstrate relatively little toxicity with exposures D. Most toxic effects involve the CNS E. None of the above

Answer C. Mammals demonstrate relatively little toxicity when exposed to Pyrethroids. Most cases of toxicity associated with pyrethrins are a results of hypersensitivity reactions. They are extracted from chrysanthemums.

Which is the most significant difference between organophosphate (OP) and carbamate agents? A. OP are more likely to lead to paralysis in acute toxicity B. OP do not cross the blood-brain barrier C. OP can undergo aging when bound to acetylcholinesterase D. OP require metabolism by mixed function oxidases to become active E. OP do no lead to dysrhythmias in acute toxicity

Answer C. OP agents have an OP-cholinesterase complex that "ages" over time. Once this has occurred that bond can not be broken and a new enzyme must be produced for the resolution of toxicity. With carbamates - the carbamate-acetylcholinesterase bond hydrolyzes spontaneously, reactivating the enzyme. So, the duration of cholinergic symptoms in carbamate toxicity is generally less than 24 hrs and they do not penetrate the blood-brain barrier well. But, seizures and CNS effects can occur with significant toxicity.

Which is true regarding occupational (occ) asthma? A. Occ asthma occurs when preexisting asthma is exacerbated by an exposure in the workplace B. Occ exposure accounts for nearly all adult-onset asthma C. There may be a long latency period between first exposure and onset of sxs D. Cleaning materials (such as ammonia) are typically indicated E. Sxs may improve with nebulized Na HCO3

Answer C. Occ asthma is caused by workplace factors only and accounts for 10-15% of adult-onset asthma. There may be a period of yrs between the first exposure and onset of sxs. Ammonia and hypochlorites more commonly are associated with reactive airway dysfunction syndrome, which is more acute in nature. Occ asthma is thought to be triggered by large organic molecules.

Rescuers of hydrogen sulfide toxic victims often become victims themselves because of olfactory fatigue and failure to smell the rotten egg odor. At what atmospheric concentration does olfactory fatigue occur? A. 1 ppm B. 10 ppm C. 100 ppm D. 1,000 ppm E. 10,000 ppm

Answer C. Olfactory paralysis occurs at ? 100 ppm and coma typically occurs at > 700 ppm. Rescuers may misperceive failure to smell the rotten eggs as a sign that it is safe to enter a contaminated environment and expose themselves to more hazardous concentration of hydrogen sulfide.

Lethargy might be the only symptom expected from repeated ingestion of which rodenticide? A. Brodifacoum B. Bromethalin C. Cholecalciferol D. Strychnine E. Vacor

Answer C. Repeated ingestion of cholecalciferol (vitamin D) would produce sxs of hypercalcemia since it mobilizes calcium from the bone. Mild-moderate elevations in calcium levels can results in lethargy and confusion.

Which toxic effect was observed in children following overuse of DEET? A. Diarrhea B. Cardiac dysrhythmias C. Seizures D. Ataxia E. Anaphylaxis

Answer C. Seizures have been reported with excessive dermal absorption and ingestion of DEET-containing products in kids. The incidence of these severe reactions is greatest with higher concentrated products.

What is the most likely clinical symptom following exposure to cyanide gas? A.V tach B. Bloody emesis C. Seizures D. Abdominal pain E. Cyanosis

Answer C. The CNS is the system most sensitive to cyanide. Sxs include headache agitation, confusion, and seizures/coma/death. Progressive cardiac failure and bradycardia (not ventricular dysrhythmias) occur. GI sxs are not common. Cyanide may occur late in profound shock but is not common.

Mass casualty with the following sxs: c/o eye pain, lacrimation, rhinorrhea, cough, N/V are least likely to occur to exposure to which biological warfare agent? A. Adamsite B. Chloracetophenone C. Hydrogen cyanide D. Sarin E. Sulfur mustard

Answer C. The described toxidrome is typical for riot control agents. Hydrogen cyanide is a weak acid and produces rapid loss of consciousness but no mucous membrane irritation.

Which is true about carbon monoxide? A. Affinity 100x > oxygen for hemoglobin B. Affinity 100x > oxygen for myoglobin C. A product of hemoglobin formation D. Binds to cytochrome oxidase E. Causes shift to the right on the oxygen-dissociation

Answer D. Affinity for hemoglobin is 200-250x greater than oxygen and 40x greater than oxygen for myoglobin. CO is a byproduct of hemoglobin degradation and binds to cytochrome oxidase. In the presence of CO and formation of carboxyhemoglobin - the remaining oxyhemoglobin offloads oxygen less readily. There is a shift to the left on the oxyhemoglobin dissociation curve

What is the active ingredient in smoke bombs? A. Sodium chloride B. Lead azide C. Sulfur dioxide D. Zinc chloride E. H2O2

Answer D. After a zinc chloride exposure acute symptoms include: tearing, rhinitis, dyspnea, stridor, retrosternal chest pain and then delayed ARDS/ALI. Toxicity is limited to the lungs. Systemic absorption is not a problem.

Treatment of victims exposed to which substance poses the greatest overall risk of contaminating healthcare providers? A. Phosgene B. Sarin C. Soman D. Sulfur mustard E. Vx

Answer D. Agents with the greatest persistence are most likely to remain on their victims and their clothing causing contamination of other things and people. Phosgene/sarin/soman are less persistent than sulfur mustard or Vx. Patients with Vx will be VERY symptomatic, if not dead, providing clear clues to HC personnel that protective gear will be necessary. Patients with sulfur mustard may initially have minimal or no sxs which can allow for lapses in contamination precautions.

Which is a common symptom of hydrogen sulfide toxicity? A. Erythroderma B. Diarrhea C. Incontinence D. Respiratory paralysis E. Metabolic alkalosis

Answer D. At higher concentrations, it causes central respiratory paralysis and metabolic acidosis. It doesn't cause any of the other symptoms.

Which is true about carbon monoxide (CO)? A. CO is denser than air B. CO is irritating C. CO is visible in high concentrations D. CO is odorless E. CO causes toxicity by binding to methemoglobin

Answer D. CO is colorless, odorless, and non irritating. It is lighter than air. It binds to hemoglobin and myoglobin.

Cyanosis, SOB, and tachypnea might be expected following which inhaled substance? A. Nitrous oxide B. Toluene C. Trichloroethane D. Isobutyl nitrite E. Methylene chloride

Answer D. Cyanosis suggests methemoglobinemia so look for the NITRITE answer. SOB and tachypnea are sxs of any inhalant.

Which statement about DEET (diethyl-meta-toluamide) is correct? A. It is available to the consumer in concentration 5-10% B. It is often combined with pyrethrins C. DEET is poorly absorbed through the skin D. DEET and several active metabolites can be found in fat for up to 2 months after dermal application E. Lower concentrated products are not as effective as the higher concentrated products

Answer D. DEET and several active metabolites can be found in fat for up to 2 months after dermal exposure. Currently the lower concentrated products are of comparable efficacy to the higher concentrated products.

What is the basis for the relative lack of human toxicity of the glyphosates? A. It undergoes extensive first pass metabolism in the liver B. It has very little use outside specialized plantation crops C. It is a less potent inhibitor of mammalian cholinesterase D. It interferes with biosynthesis of aromatic amino acids needed for chlorophyll E. It can't pass membranes due to its charge

Answer D. Glyphosate is poorly absorbed and excreted unchanged in the urine. The pathway for chlorophyll synthesis exists in plants (biosynthesis of aromatic amino acids) but not mammals, leaving us unaffected.

Which is a source of hydrogen sulfide (HS)? A. Decomposition of grain in silos B. Incomplete combustion of silk C. Combination of ammonia and hypochlorite D. Sewers E. Mercury refining

Answer D. HS is a byproduct of industrial processes such as paper and leather production, vulcanization of rubber and natural gas refining. HS is a natural product of bacterial decomposition of protein and sulfur-containing substances (SEWAGE) and of volcanoes, sulfur springs, and underground gas deposits.

Indications for early intubation in smoke victims include: A. Wheezing B. Myocardial ischemia C. Persistent cough D. Edematous oropharynx with carbonaceous sputum E. Burns of the face

Answer D. Indications for early intubation include CNS depression, stridor, full thickness circumferential burns and oropharyngeal edema.

At usual doses achieved through smoking, nicotine can be expected to produce which effect? A. Increased irritability B. Muscle weakness C. Increased lower respiratory sphincter tone D. Improved memory E. Decreased humoral production

Answer D. Nicotine decreases irritability, decreases esophageal tone, stimulates neurohumoral production, and improves memory and attention.

Which rodenticide is considered "selective" - which targets the desired species more than humans and pets? A. Yellow phosphorus B. Sodium monofluoroacetate (SMFA) C. Warfarin D. Norbormide E. Vacor

Answer D. Norbormide is an irreversible smooth muscle constrictor that causes ischemic necrosis and death in rats but not other animals. Presumably because it acts on a specific smooth-muscle norbormide receptor found only in rats. All inorganic rodenticides (yellow phos) along with organic rodenticides (SMFA and strychnine) are "nonselective". Vacor was erroneously thought to be selective for rodents - probably because LD 50 varies from species to species with no particular logical sequence.

Chronic toluene toxicity is clinically manifested by what symptom? A. Methemoglobinemia B. "sudden sniffer's death" C. Hepatocellular necrosis (similar to APAP toxicity) D. Leukoencephalopathy E. Sensorimotor peripheral neuropathy

Answer D. Patients with toluene leukoencephalopathy (dementia, ataxia, eye movement disorders, anosmia) display characteristic neurobehavioral deficits reflecting white matter involvement like inattention, apathy, impaired memory and visuospatial skills with preservation of language.

Which best describes phosgene? A. Phosgene toxicity no longer occurs since its use was banned by the Geneva Convention B. Prolonged exposure is unlikely because of its foul odor C. Dissolution in mucosal water is rapid but the onset of toxicity is delayed D. Once it has dissolved, the acidic products generate influx of inflammatory cells E. Pulmonary toxicity can be completely averted with IV NAC

Answer D. Use of phosgene as a war gas was banned but it is still used in industry and following fire smoke exposure. It has a pleasant odor - "freshly cut hay". Its dissolution in lung water is slow, but once dissolved, it generates acid products that incite an inflammatory response. IV NAC has been used to limit inflammatory influx but without dramatic success

The most important physical property of a XB within smoke that determines the location of lung injury is which factor? A. pH B. Molecular weight C. Particle size D. Water solubility E. Charge

Answer D. Water solubility is most important of an irritant XB in determining the level of respiratory tract injury. Highly water soluble gases react with upper airway mucosal water to produce an intense inflammatory reaction. Unless the irritant gas concentrations are extremely high or prolonged exposure occurs, injury is limited to upper airways. Conversely, chemicals with low water solubility do not react with upper airway mucosa and are ABLE TO REACH LUNG PARENCHYMA

Which might be a delayed or persistent neuropsychological sequelae after CO toxicity? A. Memory/learning problems B. Cortical blindness C. Parkinsonism D. Incontinence E. All of the above

Answer E. All have been reported after long term follow up from CO toxicity

As nicotine toxicity progresses from early phase to the late phase, which change is likely to occur? A. Muscle fasciculation à muscle paralysis B. CNS stimulation à CNS depression C. Tachycardia à bradycardia D. Hypertension à hypotension E. All of the above

Answer E. All of the above

Which statement about carbon monoxide (CO) toxicity is true? A. Peak maternal COHgb (carboxyhemoglobin) exceeds peak fetal COHgb B. Lower fetal PO2 diminishes adverse effects of fetal COHgb C. Therapy with 100% oxygen may be discontinued when maternal COHgb returns to a normal level D. Hyperbaric oxygen (HBO) should be administered for a period of time equal to twice the standard length of treatment E. Fetal toxicity is generally greater than maternal toxicity

Answer E. CO toxicity may lead to adverse fetal effects even when maternal toxicity is inconsequential. Peak fetal COHgb generally exceeds maternal concentration and peaks at a later time. For this reason, it is recommended that oxygen be continued for a period of time 5 times as long as it takes to lower the maternal concentration to normal. Lower fetal PO2 and the greater affinity of fetal hemoglobin to CO exacerbates the effects of CO exposure. HBO should be considered in all cases of CO toxicity but is not necessarily for a longer time.

Which is a potential source of cyanide poisoning? A. Automobile exhaust B. Ingestion of orange pits C. Burning of coal D. Burning of wood E. Nipride treatment

Answer E. Cyanide is a significant cause of death in fire victims, however, wood fires do not result in formation of cyanide. Cyanide can occur from Nipride administration when used for a prolonged period of time in the presence of renal failure. It is commonly administered in the same bag as sodium thiosulfate. The cyanide combines with the thiosulfate to form the less toxic sodium thiocyanate which is excreted.

Which of the following is consistent with cyanide toxicity? A. Lowered central venous oxygen saturation B. Normal gap metabolic acidosis C. Hypoglycemia D. Hypophosphatemia E. Elevated lactate level

Answer E. Cyanide results in anion gap metabolic acidosis and an increase in lactate concentrations. In fact, high lactate levels are suspicious of cyanide toxicity (>10 and refractory to resuscitation)

Which gas is a chemical asphyxiant? A. Propane B. Methane C. Hydrogen chloride D. Chloramine E. Cyanide

Answer E. Cyanide, hydrozoic acid ( liberator of azide) and hydrogen sulfide all poison the cytochrome oxidase chain leading to anaerobic respiration and metabolic organ failure by interfering with the oxygen loading and unloading.

Nicotine is least well absorbed from which site? A. Oral mucosa B. Lung C. Small intestine D. Skin E. Stomach

Answer E. Nicotine is poorly absorbed in the stomach in acidic environments. Alkaline environs (oral, skin, lungs and small intestine) have better absorption. Recall that green-leaf tobacco sickness occurs with workers harvesting tobacco leaves without skin protection.

What toxic gas is formed from combustion of polyvinylchloride? A. CO B. Hydrochloric acid C. Phosgene D. Chlorine E. All of the above

Answer E. Polyvinylchloride (PVC) is widely used in furnishings, floor coverings, and electrical insulation - all commonly found in house fires

Which is a simple asphyxiant? A. Carbon monoxide B. Hydrogen sulfide C. Hydrogen chloride D. Nitrogen dioxide E. Nitrogen

Answer E. Simple asphyxiants have no direct pulmonary or systemic toxicity. Nitrogen is the only simple asphyxiant.

Which gas is heavier than air? A. CO B. Cyanide C. Neon D. Methane E. Methyl bromide

Answer E. The molecular weight of air (78% nitrogen, 21% oxygen) is just under 29. The following are increasing molecular weight: Hydrogen 1 Oxygen 32 Carbon 12 Hydrogen sulfide 34 Methane 16 Propane 46 Neon 20 Bromine 80 Cyanide26 Methylbromide 95 CO and nitrogen 28

Which chemical weapon is most potent (has the lowest lethal exposure dose)? A.Chloroacetophenone B.Hydrogen cyanide C.Sarin D.Tabun E.Vx

Answer E. Vx is THE MOST POTENT, has the least volatility and has the greatest persistence. It is an oily liquid at standard room temperature. Did you ever see The Rock, with Nicholas Cage and Sean Connery? That was the substance used. Watch the movie and you'll never get any questions about Vx wrong.

CO (carbon monoxide) mechanism of action

CO binds with affinity to hgb of 250 times greater than oxygen; since CO cannot carry oxygen tissue hypoxia occurs. Also there is a shift to the left on the oxygen dissociation curve (shift to the Left means you hoLd onto your oxygen and don't release it to the starved tissues).

Fun Facts about Fetal CO Exposures

Fetal Compromise 1.Fetal Hgb has a higher affinity for CO than for maternal Hgb 2.Maternal Hgb there fore does not reflect the degree of poisoning in the fetus 3.Fetal demise and stillbirths may occur at low maternal COHgb levels

In evaluting a patient who ingested an unknown rodenticide, which correctly pairs symptoms with the associated rodenticide? A. Hair loss à strychnine B. Opisthotonos à barium carbonate C. Garlic odor of stools à zinc phosphide D. "smoking" vomitus/stools à white/yellow phosphorus E. Risus sardonicus à thallium

In evaluting a patient who ingested an unknown rodenticide, which correctly pairs symptoms with the associated rodenticide? A.Hair loss à strychnine B.Opisthotonos à barium carbonate C.Garlic odor of stools à zinc phosphide D."smoking" vomitus/stools à white/yellow phosphorus E.Risus sardonicus à thallium

Cherry red color of the skin in CO exposures accounts for how many?

Not many; only occurs in 2-3% of patients

CO Half-Life

Room air ~ 4-6 hrs on high flow oxygen ~ 40-90 mins with HBO ~12-20 mins

Sources of CO

Sources: products of combustion, propane powered vehicles (Zamboni, tractor exhaust, forklifts), gas stoves, kerosene heaters, indoor hibachi use (with poor ventilation), gas powered dryers and hot water heaters Halogenated hydrocarbons metabolized into CO à methylene chloride (varnish removers) and inhalational anesthetics (enflurane, desflurane, isoflurane)

Cyanide mechanism of action

despite adequate oxygen, ATP cannot be formed which results in cellular hypoxia

symptoms of cyanide poisoning

headache, N/V, HTN à hypotension, tachypnea à bradypnea, altered LOC, collapse, seizures, cyanosis only occurs in late stages from shock - usually before death

Cyanide Sources:

laetrile, cassava root, amygdalin, silver/gold extraction, products of combustion, acetonitrile (artificial nail remover)

Cyanide tox Treatment

nitrites/nitrates to purposely induce methemoglobinemia, hydroxocobalamin