STUDY - Technical - New Dacian's Medicine
Fever
and hyperthermia (2)
Translation Draft
Let's continue the little introduction to "temperature"...
The science and art of medicine combine in the diagnosis of a febrile disease, in no clinical situation is a more meticulous anamnesis more important.
From the outset, extreme attention should be paid to the chronology of symptoms in relation to the use of medicines (including medicines that could be administered without a doctor's prescription, which are constituted in a current practice of patients) or treatments such as surgical or dental procedures.
In addition, it is necessary to accurately assess the nature of any prosthetic material and/ or implant. A careful occupational anamnesis should include exposure to animals, toxic gases, infectious and potential agents, possible antigens or contact with other febrile or infected individuals at home, at work or at school. A history of the geographical areas in which the patient lived and a travel history must include travel during military service.
Unusual habits, particularities of the diet (such as raw or "blood" meat, raw fish, milk or unpasteurised cheese) or contact with pets should also be determined, and sexual practices and orientation, including precautions used or omissed, should also be established.
Attention should be focused on the use of tobacco, marijuana, intravenous drugs or alcohol, trauma, animal bites, tick bites or other insects, previous transfusions, immunizations, drug allergies or hypersensitivity.
A careful family history should include data on family members who have contracted tuberculosis, other febrile and infectious diseases, arthritis or collagen diseases, or unusual family symptomatology, such as deafness, hives, fever and polyserositis, bone pain or anemia. Similarly, ethnic origin can be essential.
For example, blacks have a higher risk than people of other races of hemoglobinopathy, Turks, Arabs, Armenians and Jews are at high risk of having A Mediterranean family fever, etc.
Fever can be sustained, intermittent, remitted and recurrent. A sustained fever is one in which the increase in temperature is persistent, with minimal variations.
In remittance fever there is an exaggeration of normal circadian rhythm and when this variation is extremely pronounced, the fever is called hectic or septic. Intermittent, hectic and septic types are common in deep or systemic infections, in malignant states and drug fevers. When hectic fever occurs daily, the term "daily" is sometimes used. Remittance fever, in which the temperature drops every day but not to normal levels, is typical of tuberculosis, viral diseases, many bacterial infections and non-infectious febrile states.
In newborns, the elderly, patients with renal failure or chronic hepatitis, patients treated with glucocorticoids or with bacteric shock, hypothermia may be a sign of severe infection, as these people fail to generate fever.
In recurrent fever, febrile episodes are separated by normal temperature ranges and when paroxysms occur on the first and third days, the fever is called tertiary. Plasmodium vivax (one of the six "sources" of malaria) produces tertiary fever.
Quaternary fever is associated with paroxysms on the first and fourth day and is found in infections with Plasmodium malaria (the main "source" of malaria). Other recurrent febrile states occur in Borrelia infections and rat bite fever, both associated with fever periods, followed by several-day febrile periods and then the recurrence of febrile days. Pel-Ebstein fever, with febrile periods of 3 to 10 days, followed by afebrile periods of 3 to 10 days, is classic for Hodkin's disease and other lymphomas. Another type of fever is that of cyclic neutropenia, in which fever occurs every 21 days and is accompanied by neutropenia.
With regard to types of fever, the wide use of antipyretics, glucocorticoids and antibiotics may complicate identification, including that "classic fever" is hard to observe. However, some types are clinically useful. While circadian temperature variation is preserved and accentuated in most febrile states, a reversal of this variation can be observed in typhoid fever and disseminated tuberculosis.
Temperature-pulse dissociation (relative bradycardia) is found in typhoid fever, as in brucellosis, leptospirosis, some febrile drug states and many febrile states caused. Bradicardia in the presence of fever can also signify cardiac conduction disorders, as in the case of acute articular rheumatism, Lyme disease, viral myocarditis or abscesses of valvular rings that can complicate bacterial endocarditis.
As far as the physical examination is concerned, it should be repeated, meticulously, at regular intervals, all vital signs being relevant. The temperature can be measured orally or rectally, but the same measuring place should be maintained. The axillary temperature is known to be misleading, as is the oral temperature after ingestion of hot or cold drinks, smoking or hyperventilation.
In some cases, patients are carefully examined at the time of the initial assessment, but then the focus is shifted to laboratory data and other diagnostic procedures. Particular attention should be paid to a daily physical examination (sometimes even frequently) until the diagnosis is certain and the anticipated response has been obtained.
Special attention should be paid to skin, lymph nodes, eyes, nail beds, cardiovascular system, chest, abdomen, musculoskeletal system and nervous system. Rectal examination is mandatory. The penis, prostate, scrotum and testicles should be carefully examined and the foreskin, if any, should be retracted. Pelvic examination should be part of any complete physical examination for women.
In terms of laboratory investigations, there are few signs and symptoms in medicine that raise as many diagnostic possibilities as fever. If anamnesis, epidemiological circumstances or physical examination suggest more than a simple viral infection or streptococcal pharyngitis, laboratory investigations are recommended.
The pace and complexity of the required tests will be influenced by the evolution of the disease, the diagnostic considerations and the immune status of the host. If the signs are focal or if anamnesis, epidemiological data and clinical examination suggest a specific diagnosis, then laboratory investigations can be targeted. If the fever is undifferentiated, the 'diagnostic beach' should be widened and it is necessary to follow up certain recommendations set out below.
It is worrying how frequently "routine", "ordinary" prescriptions are used for antipyretics (such as acetaminophen), in the case of a temperature exceeding an arbitrary level, also frequently encountering conscious, alerted patients, but with severe discomfort and strong chills. Such therapies have their appropriate indications, but are commonly used without therapeutic reasoning. So the first decision to be taken is to determine whether a high temperature is fever or hyperthermia.
Hyperthermia is an increase in central temperature without increasing the threshold of hypothalamic regulation. Hypothermia is most commonly due to inadequate heat dissipation, although the most rare primary cause is excessive heat production, with inadequate dissipation to compensate for it.
Heat attack, caused by insufficient thermoregulation in combination with a warm environment, can be observed in effort or without effort. Stress heat attack occurs in young individuals, who strive at ambient temperatures and/ or at humidity that are higher than normal.
Even in normal individuals, dehydration or the use of ordinary medicines (e.g. excess antihistamines with anticholinergic side effects) can help precipitate the stress heat attack. Classic heat attack in lack of effort occurs typically in older individuals, especially during heat waves.
Elderly, bet-tight, anticholinergic, antiparkinsonian or diuretic, and individuals with poor ventilation, or those in air-conditioned environments are most susceptible.
Drug-induced hyperthermia has become increasingly common as a result of increased use of prescribed or illegal psychotropic drugs. Drug-induced hyperthemia can be caused by monoaminooxidase inhibitors, tricyclic antidepressants, amphetamines and the outlaw use of fencyclidine, diethylamide lysergic acid (LSD), or cocaine. Malignant hyperthermia is an inherited abnormality of the sarcopalmic reticulum in the skeletal muscle, which leads to a rapid increase in intracellular calcium levels in response to halotan and other inhalant anesthetics or succinylcholine.
High temperature, increased muscle metabolism, stiffness, rhabdomyolysis, acidosis and cardiovascular instability occur rapidly. Termination of anesthesia and administration of dantrolen sodium are therapies with immediate indication.
Neuroleptic malignant syndrome can occur when taking phenothiazines and other drugs, such as haloperidol, and is characterized by muscle stiffness, autonomic dysfunction and hyperthermia. This disorder appears to be due to inhibition of central dopaminergic receptors in the hypothalamus, leading to increased heat production and decreased heat dissipation. Thyrotoxicosis and pheochromocytoma can also cause increased thermogenesis.
An increased central temperature in a patient at risk of hyperthermia (due to exposure to the environment or treatment with anticholinergic or neuroleptic drugs, tricyclic antidepressants, succinylcholine or halotan), together with appropriate clinical signs (dry skin, hallucinations, delirium, pupil dilation, muscle stiffness and/ or increases in creatine phosphokinase levels) is characteristic for hyperthermia. The attempt to lower the already normal adjustment threshold of the hypothalamus has a low efficiency.
Physical cooling by watering, rubs, wet and cold blankets and even ice baths should be carried out immediately, together with the administration of appropriate pharmacological agents (such as dantrolen in the case of malignant hyperthermia or neuroleptic malignant syndrome or physiostigmine for overdoses of tricyclic antidepressants).
If cooling by external means is insufficient, internal cooling can be obtained by gastric or peritoneal lavage with saline ice solutions. In extreme circumstances, hemodialysis or even cardiopulmonary bypass can be done with blood cooling.
In hyperpyrexia (temperature greater than 41 degrees Celsius), treatment with antipyretics is clearly indicated and physical cooling during the restoration of the threshold of hypothalamic adjustment by antipyretic scan will speed up the process. Antipyretics also suppress the constitutional symptoms that accompany fever (myalgia, chills, headache).
However, for low or moderate fever, there is little data to show that it is harmful or that antipyretic therapy is beneficial, with the exceptions mentioned related to children with febrile seizures, pregnant women and patients with impaired heart, lung or brain function.
The temperature is often unnecessarily low and "routine" antipyretic prescriptions can mask important clinical information obtained from tracking the variation of the patient's febrile curve. Nonsteroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids can mask the inflammatory characters of a localized infection, thus preventing its detection and even causing dissemination. In addition, the medicines themselves can give side effects.
And to complete, I have a little more to say about the septic state. It is defined as evidence of an infection with a systemic response. Septic syndrome refers to a systemic response sufficient to produce an organ dysfunction, and septic shock is septic syndrome associated with hypotension. In these cases the establishment of medical therapy is of an emergency nature, the causes of their production being multiple and the consequences being the most serious.
Let's continue the little introduction to "temperature"...
The science and art of medicine combine in the diagnosis of a febrile disease, in no clinical situation is a more meticulous anamnesis more important.
From the outset, extreme attention should be paid to the chronology of symptoms in relation to the use of medicines (including medicines that could be administered without a doctor's prescription, which are constituted in a current practice of patients) or treatments such as surgical or dental procedures.
In addition, it is necessary to accurately assess the nature of any prosthetic material and/ or implant. A careful occupational anamnesis should include exposure to animals, toxic gases, infectious and potential agents, possible antigens or contact with other febrile or infected individuals at home, at work or at school. A history of the geographical areas in which the patient lived and a travel history must include travel during military service.
Unusual habits, particularities of the diet (such as raw or "blood" meat, raw fish, milk or unpasteurised cheese) or contact with pets should also be determined, and sexual practices and orientation, including precautions used or omissed, should also be established.
Attention should be focused on the use of tobacco, marijuana, intravenous drugs or alcohol, trauma, animal bites, tick bites or other insects, previous transfusions, immunizations, drug allergies or hypersensitivity.
A careful family history should include data on family members who have contracted tuberculosis, other febrile and infectious diseases, arthritis or collagen diseases, or unusual family symptomatology, such as deafness, hives, fever and polyserositis, bone pain or anemia. Similarly, ethnic origin can be essential.
For example, blacks have a higher risk than people of other races of hemoglobinopathy, Turks, Arabs, Armenians and Jews are at high risk of having A Mediterranean family fever, etc.
Fever can be sustained, intermittent, remitted and recurrent. A sustained fever is one in which the increase in temperature is persistent, with minimal variations.
In remittance fever there is an exaggeration of normal circadian rhythm and when this variation is extremely pronounced, the fever is called hectic or septic. Intermittent, hectic and septic types are common in deep or systemic infections, in malignant states and drug fevers. When hectic fever occurs daily, the term "daily" is sometimes used. Remittance fever, in which the temperature drops every day but not to normal levels, is typical of tuberculosis, viral diseases, many bacterial infections and non-infectious febrile states.
In newborns, the elderly, patients with renal failure or chronic hepatitis, patients treated with glucocorticoids or with bacteric shock, hypothermia may be a sign of severe infection, as these people fail to generate fever.
In recurrent fever, febrile episodes are separated by normal temperature ranges and when paroxysms occur on the first and third days, the fever is called tertiary. Plasmodium vivax (one of the six "sources" of malaria) produces tertiary fever.
Quaternary fever is associated with paroxysms on the first and fourth day and is found in infections with Plasmodium malaria (the main "source" of malaria). Other recurrent febrile states occur in Borrelia infections and rat bite fever, both associated with fever periods, followed by several-day febrile periods and then the recurrence of febrile days. Pel-Ebstein fever, with febrile periods of 3 to 10 days, followed by afebrile periods of 3 to 10 days, is classic for Hodkin's disease and other lymphomas. Another type of fever is that of cyclic neutropenia, in which fever occurs every 21 days and is accompanied by neutropenia.
With regard to types of fever, the wide use of antipyretics, glucocorticoids and antibiotics may complicate identification, including that "classic fever" is hard to observe. However, some types are clinically useful. While circadian temperature variation is preserved and accentuated in most febrile states, a reversal of this variation can be observed in typhoid fever and disseminated tuberculosis.
Temperature-pulse dissociation (relative bradycardia) is found in typhoid fever, as in brucellosis, leptospirosis, some febrile drug states and many febrile states caused. Bradicardia in the presence of fever can also signify cardiac conduction disorders, as in the case of acute articular rheumatism, Lyme disease, viral myocarditis or abscesses of valvular rings that can complicate bacterial endocarditis.
As far as the physical examination is concerned, it should be repeated, meticulously, at regular intervals, all vital signs being relevant. The temperature can be measured orally or rectally, but the same measuring place should be maintained. The axillary temperature is known to be misleading, as is the oral temperature after ingestion of hot or cold drinks, smoking or hyperventilation.
In some cases, patients are carefully examined at the time of the initial assessment, but then the focus is shifted to laboratory data and other diagnostic procedures. Particular attention should be paid to a daily physical examination (sometimes even frequently) until the diagnosis is certain and the anticipated response has been obtained.
Special attention should be paid to skin, lymph nodes, eyes, nail beds, cardiovascular system, chest, abdomen, musculoskeletal system and nervous system. Rectal examination is mandatory. The penis, prostate, scrotum and testicles should be carefully examined and the foreskin, if any, should be retracted. Pelvic examination should be part of any complete physical examination for women.
In terms of laboratory investigations, there are few signs and symptoms in medicine that raise as many diagnostic possibilities as fever. If anamnesis, epidemiological circumstances or physical examination suggest more than a simple viral infection or streptococcal pharyngitis, laboratory investigations are recommended.
The pace and complexity of the required tests will be influenced by the evolution of the disease, the diagnostic considerations and the immune status of the host. If the signs are focal or if anamnesis, epidemiological data and clinical examination suggest a specific diagnosis, then laboratory investigations can be targeted. If the fever is undifferentiated, the 'diagnostic beach' should be widened and it is necessary to follow up certain recommendations set out below.
It is worrying how frequently "routine", "ordinary" prescriptions are used for antipyretics (such as acetaminophen), in the case of a temperature exceeding an arbitrary level, also frequently encountering conscious, alerted patients, but with severe discomfort and strong chills. Such therapies have their appropriate indications, but are commonly used without therapeutic reasoning. So the first decision to be taken is to determine whether a high temperature is fever or hyperthermia.
Hyperthermia is an increase in central temperature without increasing the threshold of hypothalamic regulation. Hypothermia is most commonly due to inadequate heat dissipation, although the most rare primary cause is excessive heat production, with inadequate dissipation to compensate for it.
Heat attack, caused by insufficient thermoregulation in combination with a warm environment, can be observed in effort or without effort. Stress heat attack occurs in young individuals, who strive at ambient temperatures and/ or at humidity that are higher than normal.
Even in normal individuals, dehydration or the use of ordinary medicines (e.g. excess antihistamines with anticholinergic side effects) can help precipitate the stress heat attack. Classic heat attack in lack of effort occurs typically in older individuals, especially during heat waves.
Elderly, bet-tight, anticholinergic, antiparkinsonian or diuretic, and individuals with poor ventilation, or those in air-conditioned environments are most susceptible.
Drug-induced hyperthermia has become increasingly common as a result of increased use of prescribed or illegal psychotropic drugs. Drug-induced hyperthemia can be caused by monoaminooxidase inhibitors, tricyclic antidepressants, amphetamines and the outlaw use of fencyclidine, diethylamide lysergic acid (LSD), or cocaine. Malignant hyperthermia is an inherited abnormality of the sarcopalmic reticulum in the skeletal muscle, which leads to a rapid increase in intracellular calcium levels in response to halotan and other inhalant anesthetics or succinylcholine.
High temperature, increased muscle metabolism, stiffness, rhabdomyolysis, acidosis and cardiovascular instability occur rapidly. Termination of anesthesia and administration of dantrolen sodium are therapies with immediate indication.
Neuroleptic malignant syndrome can occur when taking phenothiazines and other drugs, such as haloperidol, and is characterized by muscle stiffness, autonomic dysfunction and hyperthermia. This disorder appears to be due to inhibition of central dopaminergic receptors in the hypothalamus, leading to increased heat production and decreased heat dissipation. Thyrotoxicosis and pheochromocytoma can also cause increased thermogenesis.
An increased central temperature in a patient at risk of hyperthermia (due to exposure to the environment or treatment with anticholinergic or neuroleptic drugs, tricyclic antidepressants, succinylcholine or halotan), together with appropriate clinical signs (dry skin, hallucinations, delirium, pupil dilation, muscle stiffness and/ or increases in creatine phosphokinase levels) is characteristic for hyperthermia. The attempt to lower the already normal adjustment threshold of the hypothalamus has a low efficiency.
Physical cooling by watering, rubs, wet and cold blankets and even ice baths should be carried out immediately, together with the administration of appropriate pharmacological agents (such as dantrolen in the case of malignant hyperthermia or neuroleptic malignant syndrome or physiostigmine for overdoses of tricyclic antidepressants).
If cooling by external means is insufficient, internal cooling can be obtained by gastric or peritoneal lavage with saline ice solutions. In extreme circumstances, hemodialysis or even cardiopulmonary bypass can be done with blood cooling.
In hyperpyrexia (temperature greater than 41 degrees Celsius), treatment with antipyretics is clearly indicated and physical cooling during the restoration of the threshold of hypothalamic adjustment by antipyretic scan will speed up the process. Antipyretics also suppress the constitutional symptoms that accompany fever (myalgia, chills, headache).
However, for low or moderate fever, there is little data to show that it is harmful or that antipyretic therapy is beneficial, with the exceptions mentioned related to children with febrile seizures, pregnant women and patients with impaired heart, lung or brain function.
The temperature is often unnecessarily low and "routine" antipyretic prescriptions can mask important clinical information obtained from tracking the variation of the patient's febrile curve. Nonsteroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids can mask the inflammatory characters of a localized infection, thus preventing its detection and even causing dissemination. In addition, the medicines themselves can give side effects.
And to complete, I have a little more to say about the septic state. It is defined as evidence of an infection with a systemic response. Septic syndrome refers to a systemic response sufficient to produce an organ dysfunction, and septic shock is septic syndrome associated with hypotension. In these cases the establishment of medical therapy is of an emergency nature, the causes of their production being multiple and the consequences being the most serious.
There
is no day of the "three evil clocks"!
For
me, Tuesdays have brought me many remarkable gifts! So, I wish
you a day full of remarkable gifts!
Dorin, Merticaru