Geriatric hypothermia

Introduction to senile hypothermia Hypothermia refers to a state in which the deep temperature of the human body (rectum, esophagus, tympanic cavity) is lower than 35 ° C (95 ° F). The cause of hypothermia is caused by a heat-producing disorder, such as hypothyroidism. It is also caused by excessive heat dissipation. For example, if it is exposed to low temperature for a long time, the elderly may have insufficient body temperature, poor temperature regulation, insufficient heat preservation, and diseases. basic knowledge The proportion of the disease: the incidence rate of middle-aged and elderly people over 50 years old is about 0.006%-0.01%, and more patients with hypothyroidism Susceptible people: the elderly Mode of infection: non-infectious Complications: pancreatitis pulmonary edema pneumonia metabolic acidosis

Causes of senile hypothermia

Causes

Exogenous factors (30%):

The cause of accidental hypothermia has external causes, internal factors, most importantly exogenous factors, that is, exposure to cold environment or drowning in cold water, in addition, insufficient heat supply, as well as wind and climate humid can also pass Convection and evaporation increase body heat loss.

Intrinsic factor (30%):

Internal factors are extremely important for elderly patients with hypothermia, and can be divided into physiological and pathological causes, that is, physiological dysfunction of body temperature regulation and accompanying various basic diseases and drugs for reducing heat energy are important causes of accidental hypothermia in the elderly.

(1) Physiological reasons: the body temperature can be kept constant, and the body heat is balanced by the physiological regulation. When the human body is in a cold environment, the body excites the sympathetic nerve through the hypothalamic body temperature regulation center, and the heart rate is accelerated. Skin vasoconstriction to preserve body heat; on the other hand promote muscle chills (ie, reaction), promote thyroid and adrenal gland secretion function (late response) to increase calorie production, in the elderly, the above-mentioned autonomic thermoregulatory function occurs Obstruction, manifested as skin collateral response to cold, or even no response, and abnormal peripheral blood flow pattern (reduced peripheral blood flow at rest, can be <5ml / 100ml hand tissue / min, while normal people do not Reduce), skin temperature discrimination ability also declines, for example, the temperature difference between young people's fingers can be judged <1 °C, while the elderly finger can only distinguish the temperature difference of > 2 ° C, and some even the temperature difference is not above 5 ° C, this is not noticeable, this kind of The physiological disorder of thermoregulation is the cause of accidental hypothermia in the elderly.

(2) Pathological reasons: Although the elderly may cause primary accidental hypothermia due to physiological disorders in cold environment and body temperature regulation, more common are pathological causes, ie secondary hypothermia, many important The underlying disease can be secondary to hypothermia.

1 severe infection: sepsis can be manifested as hypothermia without fever, and is a sign of poor prognosis, so sepsis should not wait until fever to do blood culture; bronchial pneumonia with hypothermia, often caused by other causes of hypothermia, after induction Bronchopneumonia.

2 endocrine diseases: mucinous edema and hypopituitarism due to insufficient heat production, the mortality rate is significantly increased, the low temperature caused by steatorrhea may also be related to hypopituitarism, the risk of diabetes caused by hypothermia Non-diabetes is 6 times higher, which may be related to autonomic nerves, peripheral nerves and blood vessels. 50% of patients with hypoglycemia may develop hypothermia, which can be used as an important diagnostic clue to rapidly give glucose treatment, diabetes insipidus and Edison disease. Can also cause hypothermia.

3 central nervous system and motor system diseases: cerebrovascular accident, subarachnoid hemorrhage, subdural hematoma, brain tumor, cranial trauma and spinal cord injury can all disturb the hypothalamic body temperature regulation and cause hypothermia, of which Wernicke's hemorrhagic Encephalopathy (acute hemorrhagic polio) is particularly noteworthy. It is a vitamin B deficiency caused by alcoholism and is characterized by hemorrhagic lesions in the third ventricle, cerebral ventricles and papillary bones. Without thinking about this disease in time, you will lose the opportunity to apply thiamine treatment, which will make the disease that is easy to treat worse. Many neurological and motor system diseases can be restricted due to activity, hypothermia caused by hypothermia, and Parkinson's disease. It is caused by autonomic dysfunction caused by hypothermia. Falling is also one of the causes of this disease. When the elderly fall into the toilet at night, they may lie on the floor for a long time due to inability to climb up, resulting in a large loss of body heat causing hypothermia.

4 drugs and alcohol: the use of drugs is a cause of a large number of hypothermia, many drugs such as sedative, benzodiazepine, antidepressants and alcohol can inhibit central and peripheral body temperature regulation mechanism caused by hypothermia, People who use medicine can feel cold, but they can't warm themselves up. The chill can also be suppressed. The drugs that are most likely to cause hypothermia, including phenothiazine antipsychotics, tricyclic antidepressants, benzodiazepines. , class and barbiturate sedative hypnotics, anesthetics, etc., such as chlorpromazine can inhibit shivering, is the most well-known cooling agent, heavy drinking not only inhibits the body temperature regulation center, but also causes hypothermia by dilating peripheral blood vessels.

5 mental factors: insanity and dementia may lack the alertness to the cold, often accompanied by thermoregulatory dysfunction, combined with the application of psychotropic drugs to induce hypothermia, depression, especially after the loss of loved ones is a common cause of hypothermia The reason is that their life courage is frustrated, they may refuse to eat, drink, and warm. In addition, antidepressants often suppress tremors and may further aggravate hypothermia.

6 other diseases: malnutrition and cachexia are also important causes of secondary hypothermia in the elderly. Burns, exfoliative dermatitis and Paget's disease can cause skin damage due to skin damage, and the body surface blood vessels are increased, causing a large loss of body heat and causing hypothermia. Acute myocardial infarction and pulmonary embolism can cause acute disturbance of body temperature regulation mechanism. Urinary incontinence can also promote hypothermia, one is to dissipate heat; secondly, when the urine comes into contact with the body, the body is cooled.

In short, the causes of senile hypothermia are multifaceted and can be broadly classified into three categories:

A. Social factors:

a. Lonely life.

b. Drink plenty of alcohol.

c. Low ambient temperature

B. Physical factors:

a. Endocrine diseases.

b. Nervous system diseases.

c. Exercise system diseases.

d. Cardiovascular disease.

e. Respiratory diseases.

f. Gastrointestinal diseases.

g. Chronic wasting disease.

h. Iatrogenic diseases.

i. Fall.

j. Severe infection.

k. Aging.

C. Spiritual factors:

a. Depression.

b. Insanity.

c. Dementia.

Pathogenesis

The pathogenesis of senile septic disease has not yet been elucidated. It is generally believed that thermoregulation of physiological dysfunction and accompanying various underlying diseases and drugs that reduce heat production are important causes of hypothermia in the elderly.

Elderly hypothermia prevention

The elderly should be reasonably nutritious, scientific diet, increase calories, pay attention to keep warm, and have basic diseases should be actively treated and recovered. In the cold winter season, even at home, it may feel cold, especially in the middle of the night when the temperature drops suddenly, so it is very important to add clothing at any time.

In terms of the choice of clothes, the materials that are comfortable, light, breathable, and warm, and excellent, and fit, too loose or tight clothes, will make the warming function lower. In addition to the body, don't forget the warmth of the head, neck, hands and feet. Some people use electric heaters to maintain indoor temperature at home. This is a good way to keep out the cold, but you should ensure that the air in the room is circulated and away from flammable materials to avoid the risk of fire or burns. As for patients with diabetes and spinal cord problems, because they are less sensitive to heat perception, it is best not to use warm-up clothes such as warm packs and electric blankets to avoid burns and not conscious.

Elderly hypothermia complications Complications pancreatitis pulmonary edema pneumonia metabolic acidosis

The most common complications are pancreatitis, pulmonary edema, pneumonia, metabolic acidosis, kidney failure and limb gangrene.

Symptoms of senile hypothermia Common symptoms Hypotension, convulsions, illusion, chills, vocalization, vocal dysfunction, dysfunction, pupil size

Whether it is primary or secondary hypothermia, all systems and organs of the body can suffer varying degrees of damage, but clinical manifestations are often non-specific.

Appearance

Due to the mixed appearance of pale and blemishes on the face, the patient's face is grayish, sometimes with a specific pink color and suspected of carbon monoxide poisoning, cold skin, swollen facial, sluggish speech and hoarseness can be misdiagnosed as mucinous edema, when the patient's body temperature returns to normal The above symptoms disappeared.

2. Central nervous system

Mild hypothermia, chills, central nervous system showing ataxia, dementia, dysphonia or slow, hallucinations, etc., often mistaken for "aging", body temperature <32 ° C, chills disappear, slow reflection, Substitute to increase muscle tension, and appear paralyzed and lethargic, when the body temperature <25 ° C, the patient is coma, the reflex disappears, the pupil size on both sides is not equal, and the response to light is weak.

3. Respiratory system

At the beginning, the inhibition of the respiratory center is not obvious, and the symptoms are few. As the body temperature drops, the breathing becomes slower and shallower, and the ventilation is insufficient. The voice of the lungs is not completely due to infection, and there may be pulmonary edema due to mental confusion. Reduced cough reflexes, and cold stimulation of the bronchopulmonary, resulting in increased secretion, difficulty in removing sputum, can lead to aspiration pneumonia, pulmonary edema, secondary infection and atelectasis, the latter can smell sputum, low temperature The hemoglobin oxygenation curve shifts to the left, reducing oxygen release at the tissue level, increasing anaerobic metabolism and reducing respiratory ventilation, leading to severe respiratory acidosis and ultimately respiratory failure.

4. Cardiovascular system

Common cardiac output reduction, hypotension, bradycardia and atrial fibrillation, if there is tachycardia should be hypoglycemic hypothermia, ECG often shows different degrees of conduction block, and can have indoor conduction delay, can also appear Various forms of arrhythmia, including atrial fibrillation, atrial flutter, ventricular premature contraction, and ventricular autonomous rhythm. The more common ECG changes are small regular baseline oscillations, which are formed by increased muscle tension that does not detect trembling. When the body temperature is <32 °C, 1/3 of the patients may have characteristic tortuosity at the end of the QRS wave and the ST segment, that is, the "J" wave (Osbom wave), especially in the left anterior lead, which is a positive wave. The right side is negative, although there is no prognostic significance, but it only occurs in hypothermia, ventricular fibrillation can occur at body temperature <28 °C, and eventually can cause cardiac arrest.

5. Urinary system

In patients with hypothermia, due to ischemia and cold damage to the kidney, oliguria and acute tubular necrosis can occur. In the early stage, due to decreased renal tubular activity, "cold polyuria" may also occur, resulting in hypovolemia and pre-renality. Nitrogenemia.

6. Digestive system

Often acute pancreatitis and mumps, the former often lack of signs, only serum amylase increased, such as forced compression of the upper abdomen patients who cringe and suspected of this disease, gastrointestinal function often obstacles, peristalsis weakened, paralysis Sexual intestinal obstruction and gastrointestinal bleeding, abdominal bloating and bowel sounds weakened, blood pH decreased when liver function was impaired, and liver detoxification ability was low.

7. Blood system

Blood concentration, increased blood viscosity, thrombocytopenia, and DIC can occur.

8. Endocrine system

Due to decreased insulin release and decreased effect, glucose utilization can be reduced, hyperglycemia can occur, and adrenal cortical damage can be misdiagnosed as Addison's disease, but when the body temperature rises, the symptoms disappear, and the thyroid and pituitary functions are damaged to varying degrees.

Elderly hypothermia examination

Most laboratory data for hypothermia are non-specific, including white blood cells, platelet count, prothrombin time, fibrinogen, blood glucose, serum amylase, blood urea nitrogen, serum aspartate aminotransferase, aJ hydroxyacid dehydrogenase (HBD) ) and creatine phosphokinase (CPK), renal function and arterial blood gas analysis, such as thrombocytopenia, blood urea nitrogen, serum amylase and other enzymes above increased levels should be thought of this disease, in addition to the determination of serum triiodide by radioimmunoassay Thyrolysine (T3), thyroxine (T4) and thyrotropin (TSH) levels can be diagnosed as hypothermia caused by primary mucinous edema. Serum T3 and T4 levels are decreased and TSH is elevated. Non-mucinous The hypothermia caused by edema is still not able to reach this level.

Electrocardiograms often exhibit varying degrees of conduction block and can cause indoor conduction delays.

Diagnosis and diagnosis of senile hypothermia

Diagnostic criteria

Physicians need to be highly vigilant in order to diagnose hypothermia in a timely manner. Because hypothermia is often misdiagnosed, medical staff are wary of finding and excluding fever, and negligently searching for and eliminating hypothermia. The diagnosis of accidental hypothermia includes medical history. , clinical symptoms, physical examination and laboratory tests, elderly patients with hypothermia often live alone, in the medical history often go to bed at night to be exposed to the cold environment, clinical symptoms, the following signs should be suspected and the disease:

1 facial swelling, skin waxy pale, or specific pink;

2 side body, upper limb or lower limb tremor;

3 arrhythmia, unclear language, slower and lighter breathing and difficult to see;

4 low blood pressure;

5 lethargic or coma, unconscious, about the temperature of the body inspection method, the current known oral temperature is very unreliable for measuring deep body temperature, easy to make the disease missed, and the average body temperature can only measure 34.4 ° C for the minimum body temperature, so It is not suitable for patients with hypothermia. For suspected elderly patients who are in a cold environment or have normal body surface appearance and have a reduction in body surface temperature and various basic diseases mentioned above, a low reading thermometer should be used and inserted into the rectum for 5 minutes to measure the temperature for 5 minutes. Commonly used to measure the temperature of the body, in addition, there is a resistance thermometer placed in the external auditory canal, continuous monitoring of the deep body temperature of the ear canal, it is worth noting that when the oral temperature can not rise above 35 ° C, do not measure the rectal temperature of elderly patients can not be forgiven of.

Differential diagnosis

It is also difficult to judge various primary diseases that cause hypothermia. It should be highly vigilant because of hypothyroidism, diabetes, myocardial infarction, bronchial pneumonia, and central nervous system disorders with secondary hypothermia. Patients with symptoms, especially those in a coma, should be tested for plasma and urine for hypothermia.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.