July 4th

Happy Birthday USA. Summer is here. The forecast is for 90 + degree days for the next week. My elderly hound and I are home with the AC on, watching the World Cup. I got a little nervous when he began barking Deutcheland Uber Alles, during the morning match. The Argentine drama queens died like dogs in the second half.

Hot times in the ER lead to heat related illnesses. Heat exhaustion, sunburns, and heat stroke are all common presenting complaints during the summer. Our large elderly population is especially vulnerable to heat related conditions.

The human response to heat stress is very efficient. Vasodilitation brings increased blood flow to the skin. Sweat glands produce copious amounts of perspiration which cools us by evaporation. Respiratory rate also increases as we exhale warm air (think of a dog panting). Under most conditions and with adequate fluid replacement, humans handle heat very well. Unfortunately, lots of medical conditions, medications and social situations can lead to a failure of these compensatory mechanisms of heat dissipation.

Numerous medications, taken for many common illnesses, impair a patient's response to heat. Diuretics (water pills) tend to dehydrate the patient and may impair the kidney's ability to preserve water loss. Other blood pressure medications limit the heart rate and interfere with the shunting of blood to the skin. Many meds for depression, bipolar disorder, schizophrenia and common allergies, all impair sweating.

Medications such as doxycycline (a common antibiotic used to treat acne and other infections) can photo sensitise a patient. Someone taking these meds, who is exposed to the sun's rays may develop a painful and severe "sunburn" even when sunscreens are used. Not using sunscreens or not applying the sunblock correctly lead to sunburn. The pain of the sunburn also is accompanied by damage to the heat shedding ability of the skin. This increases the risk of heat exhaustion and heat stroke.

Lack of adequate fluid replacement is a major factor in heat illnesses. Immobility from neurological conditions, or diminished thirst from medications are especially common in the elderly. Seniors, who living alone die, every summer because of heat illnesses.

The initial symptoms of heat exhaustion may be subtle. The patient is still sweating and may only experience a vague feeling of being lightheaded. Healthy outdoor workers and athletes training in hot conditions make up many of the heat exhaustion victims. High humidity along with elevated ambient temperatures impede the cooling effect of sweating. As the body's core temperature rises, the patient becomes increasingly weak. Initial examination in the ER shows tachycardia, and hypotension. The skin is usually damp and cool to the touch. Mental function is intact early in heat exhaustion. The treatment is to get the patient out of the heat and sun. Give fluids (water is still best) and a fan may help promote evaporation.

Heat stroke is a true medical emergency. Rapid treatment is necessary to prevent damage to the brain, heart and kidneys. The patient is usually hot and dry. Mental impairment is very common. Core temperature is elevated. Readings of 103 degrees and above are the rule. Rapid cooling and rehydration are life saving. Methods of cooling vary with the extent and degree of hyperthermia. Ice packs, misting and fans, cooled IV fluids and even infusing of cooled fluids through tubes placed in the stomach, bladder and abdominal cavities may be employed. Close monitoring of cardiac rhythm, temperature, blood pressure, serum electrolytes and renal function are routine.

Even with treatment, a significant number of patient's with heat stroke will succumb to the damage occurring prior to arrival in the ER. Outdoor workers and athletes may develop rhabdomyolysis. This is destruction of muscle cells from heat stress, overuse and dehydration. The release of proteins from the damaged muscles block the filtration mechanism of the kidney and lead to renal failure.

Prevention is the best approach to heat illnesses. Avoid heavy work and exercise during high heat and humidity conditions. If you must work in the heat, protect your skin from excessive sun exposure and drink copious amounts of water. Passing urine that is adequate in amount and normal specific gravity (as a guide: the darker yellow the urine, the higher the specific gravity) may help in maintaining hydration. Look in on your elderly family members, friends and neighbors. Insure that they have air conditioning and/or fans. Encourage them to drink water regularly. Get help if you think that signs of heat exhaustion are present.

Have a safe summer. Be smart. Apply sunscreens at least 20 minutes before sun exposure and reapply frequently. Drink lots of water. Know the signs of heat illnesses and seek help as soon as possible.