Dr. Rajendran's Institute of Medical Education (RIME)

PG MEDICAL ENTRANCE EXAM 2024 MCQs

GENERAL (INTERNAL) MEDICINE

FOR MEDICAL STUDENTS (PGs AND UGs)

Wise Japanese Sayings - 29 04 24

Beginning is easy, continuing is hard.

Boasting begins where wisdom stops.

Don't count your chickens before they've hatched.

Don't offer things to people who are incapable of appreciating them.

Even a fool may be good at something.

Even when months and days are long, life is short.

Everyone has their own tastes. Respect others.

Fear is only as deep as the mind allows.

NEET EXAM 2024 - HEAT ILLNESS (8)

Must know points

Hyperthermia is defined as elevation of core body temperature above the normal diurnal range of 36 to 37.5°C due to failure of thermoregulation. Hyperthermia is not synonymous with fever, which is induced by cytokine activation during inflammation and regulated at the level of the hypothalamus. A temperature above 40.5°C (or 105°F) is severe hyperthermia.
The most important causes of severe hyperthermia (greater than 40.5°C or 105°F) caused by a failure of thermoregulation are heat stroke, neuroleptic malignant syndrome, and malignant hyperthermia.
Exertional heat illness (EHI) is among the leading causes of death in young athletes and others who exert themselves in the heat (eg, construction workers, firefighters, soldiers); there is a disturbing trend of increasing incidence. EHI is an ever-present danger when athletes or workers perform intense exercise in the heat.
Important risk factors include high ambient temperature and humidity, lack of acclimatization, dehydration, and poor physical fitness. A number of drugs and supplements, including alcohol and stimulants, increase the risk of EHI.
Exertional heat stroke (EHS) is the most dangerous type. Elevated core body temperature (above 105°F, 40.5°C) associated with altered mental status following exertion in high heat and humidity is consistent with a diagnosis of EHS.
EHS is a multisystem, life-threatening illness characterized by CNS dysfunction (encephalopathy) and additional organ and tissue damage (eg, acute kidney injury, liver injury, rhabdomyolysis) in association with high body temperatures.
- The two main diagnostic criteria are a core (eg, rectal) temperature above 40°C and CNS dysfunction.
- CNS dysfunction can manifest as disorientation, headache, irritability, emotional instability, confusion, altered consciousness, coma, or seizure.
The severity of a heat illness may not be apparent during the initial presentation. Morbidity and mortality are directly related to the duration of core temperature elevation.
First evaluate and secure the airway, breathing, and circulation. Measurements of vital signs, including a rectal temperature, fingerstick glucose, and serum sodium concentration, should be obtained quickly.
Do not use alternative methods to determine body temperature (eg, oral, tympanic, axillary, temporal, forehead sticker). If a rectal thermistor or rectal thermometer is not available, cool the patient with a severe heat illness until they begin to shiver.
"Cool-first, transport second". Rapid cooling is critical. Cold water immersion therapy is highly effective.
In circumstances when ice water immersion is not feasible, (eg, compromised airway, seizure), apply ice packs to the neck, axillae, and inguinal regions (areas adjacent to large blood vessels). Simultaneously spray moderately warm water over the patient's body and using fans to blow air over the moist skin (ie, evaporative cooling). The goal temperature is 101 to 102°F or 38.3 to 38.9°C.
Exertional heat injury is similar to EHS, but the patient's central nervous system is not affected.
Heat exhaustion and heat syncope is characterized by the inability to maintain adequate cardiac output (usually manifested as physical collapse during exercise) due to strenuous physical activity and environmental heat stress. Elevations in body temperature are less extreme than with EHS, and the central nervous system is not affected. Treatment includes moving the patient to a cool environment, with additional cooling methods used as needed, rehydration (usually with oral fluids), and careful monitoring.