Environmental Medicine Practice Questions

Q: Which of the following laboratory findings would you expect in a patient with heatstroke?

Increased hematocrit. ***Increased hematocrit*** - **Dehydration** is a hallmark of heatstroke due to excessive sweating, leading to a reduction in plasma volume [1]. - Reduced plasma volume results in a **relative increase** in the concentration of red blood cells, thus increasing the hematocrit [1]. *Hyperglycemia* - While heat stress can sometimes cause transient hyperglycemia, it is not a primary or consistent finding characteristic of heatstroke. - Heatstroke more commonly presents with **hypoglycemia** due to increased metabolic demand and depleted glycogen stores, especially in severe cases. *Low creatine kinase* - **Rhabdomyolysis**, or muscle breakdown, is a common complication of heatstroke due to prolonged high body temperature. - This muscle damage would lead to a **significantly elevated creatine kinase (CK)** level, not a low one. *Hyperkalemia* - Although electrolyte imbalances are common in heatstroke, **hyperkalemia** is not a universal or initial finding [2]. - The effects of **rhabdomyolysis** in severe heatstroke can lead to the release of intracellular potassium, potentially causing hyperkalemia, but initial presentations might show normal or even hypokalemic states depending on fluid shifts and renal function [2].

Q: A person is found unconscious due to carbon monoxide poisoning. Which of the following would be an immediate first-aid measure?

Providing 100% oxygen. ***Providing 100% oxygen*** - **100% oxygen therapy** is the immediate and most crucial first-aid measure for carbon monoxide poisoning to rapidly displace carbon monoxide from **hemoglobin** [1]. - This increases the elimination half-life of carbon monoxide from hours to minutes, restoring **oxygen-carrying capacity** to the blood and preventing further tissue hypoxia [1]. *Administering activated charcoal* - **Activated charcoal** is useful for adsorbing ingested toxins in the gastrointestinal tract, but carbon monoxide is a gas inhaled, not ingested. - It would have no effect on **inhaled carbon monoxide** that has already entered the bloodstream. *Inducing vomiting* - Inducing vomiting is a method for removing **ingested poisons** from the stomach and is not effective for inhaled toxins like carbon monoxide. - Furthermore, if the patient is unconscious, inducing vomiting carries a high risk of **aspiration**, which can lead to life-threatening complications like aspiration pneumonia [2]. *Performing CPR* - **Cardiopulmonary resuscitation (CPR)** is performed when a person's breathing or heart stops, or if they are unresponsive and not breathing normally. - While a severely poisoned patient may eventually require CPR due to **cardiac arrest**, the immediate first-aid step is to address the underlying poisoning with oxygen if they are still breathing [1].

Q: A man working in a hot environment and consuming large amounts of water without replacing salts is likely to develop -

Heat cramps. ***Heat cramps*** - **Heat cramps** are painful, involuntary muscle spasms that occur during or after strenuous activity in a hot environment, especially when there is excessive sweating and **inadequate salt replacement**. - The consumption of **large amounts of water** without replacing electrolytes further dilutes the remaining electrolytes, exacerbating the problem. *Heat hyperpyrexia* - **Heat hyperpyrexia** is characterized by a very high core body temperature (typically >106°F or 41.1°C) without central nervous system dysfunction [1]. - While it involves extreme heat exposure, the primary problem described (muscle cramps due to fluid and **electrolyte imbalance**) is not hyperpyrexia itself but a milder heat illness. *Heat stroke* - **Heat stroke** is a severe, life-threatening condition involving a dangerously elevated body temperature (>104°F or 40°C) along with **central nervous system dysfunction** (e.g., altered mental status, seizures) [1], [2]. - Although strenuous activity and heat exposure contribute, the predominant symptoms described are muscle cramps, not the systemic collapse characteristic of heat stroke. *Heat encephalopathy* - **Heat encephalopathy** refers to the neurological manifestations of severe heat illness, particularly **heat stroke**, involving altered mental status, confusion, and possibly seizures. - While heat cramps are a form of heat illness, they primarily involve muscle symptoms and do not typically include direct brain dysfunction as the primary feature.

Question 1

Which of the following laboratory findings would you expect in a patient with heatstroke?

Accepted Answer

Increased hematocrit

Answer

Hyperglycemia

Answer

Low creatine kinase

Answer

Hyperkalemia

Question 2

A person is found unconscious due to carbon monoxide poisoning. Which of the following would be an immediate first-aid measure?

Accepted Answer

Providing 100% oxygen

Answer

Administering activated charcoal

Answer

Inducing vomiting

Answer

Performing CPR

Question 3

A man working in a hot environment and consuming large amounts of water without replacing salts is likely to develop -

Accepted Answer

Heat cramps

Answer

Heat hyperpyrexia

Answer

Heat stroke

Answer

Heat encephalopathy

Question 4

Which of the following is the most important clinical principle regarding acute high-altitude pulmonary edema (HAPE)?

Accepted Answer

The primary treatment for HAPE is immediate descent to a lower altitude.

Answer

HAPE is more common at altitudes above 2500 meters but can occur at lower altitudes.

Answer

Elevated ESR is the most specific diagnostic marker for HAPE

Answer

HAPE only occurs at altitudes above 4000 meters

Environmental Medicine — MCQs

Environmental Medicine — MCQs

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