Fever in icu

Fever in icu

1. FEVER IN ICU SAMIR EL ANSARY

2. Global Critical Care https://www.facebook.com/groups/1451610115129555/#!/groups/1451610115129555/ Wellcome in our new group ..... Dr.SAMIR EL ANSARY

3. T emperature constitutes a fever A temperature of 38°C (100.4"F) in infants or 38.3"C (100.9"F) in adults defines a fever. However, immunocompromised or functionally immunocompromised patients may not be able to mount a temperature high enough to constitute a fever by this definition. In these patients low-grade temperature elevations should be addressed cautiously. Examples of patients in which the clinician should maintain a high index of suspicion for masked fever include the elderly, diabetics, intravenous drug users, chronic alcoholics, people with HIV / AIDS, people on chronic steroids or immune-modulating drugs, and neutropenic patients. rectal temperature measurement is necessary.

4. T emperature constitutes a fever A temperature of 38°C (100.4"F) in infants or 38.3"C (100.9"F) in adults defines a fever. However, immunocompromised or functionally immunocompromised patients may not be able to mount a temperature high enough to constitute a fever by this definition.

5. In these patients low-grade temperature elevations should be addressed cautiously. Examples of patients in which the clinician should maintain a high index of suspicion for Masked fever include the elderly, diabetics, intravenous drug users, chronic alcoholics, people with HIV / AIDS, people on chronic steroids or immune-modulating drugs, and neutropenic patients.

6. Methods of measuring temperature equivalent Rectal temperatures Are the most accurate representation of core body temperature and are, therefore, considered the gold standard. Oral, axillary , and tympanic temperature measurements lack sensitivity And thus a lack of fever when measured by these methods does not rule out a fever.

7. Methods of measuring temperature equivalent In addition, there is no reliable correction factor for these alternate modalities. When an accurate temperature measurement is crucial to the patient's care A rectal temperature measurement is necessary.

8. How does the body create fever? Core body temperature is controlled by the anterior hypothalamus . A fever is caused by elevation of the hypothalamic set point. The body responds by attempting to generate heat (e.g., by shivering or by increasing the basal metabolic rate) to elevate core temperature.

9. The difference between a fever and hyperthermia In contrast to fever, hyperthermia results in an elevated temperature without alteration of the hypothalamic set point . In cases of hyperthermia, the body attempts to cool itself to achieve a normal temperature, primarily by increasing sweating.

10. A temperature of 41.5"C (106.7"F) or greater usually represents hyperthermia and not a true fever, especially in adults.

11. Some examples of hyperthermia include Heat stroke, thyroid storm, burns, and toxidromes , such as neuroleptic malignant syndrome, serotonin syndrome, and malignant hyperthermia.

12. How do I address a patient with a subjective fever at home who is afebrile in the ED? This situation is mostly commonly encountered in pediatrics. Mothers are accurate in assessing the presence or absence of a fever 50% to 80% of the time, and they seem to be more accurate at detecting when the child is febrile than they are at determining that the child is afebrile .

13. Most experts feel that palpable fevers reported by mothers are probably real and need to be taken seriously. Additionally, the practice of attributing fevers to bundling has been disproved; bundling does not alter core body temperatures in infants.

14. Does the degree of fever indicate the severity of the illness? In general, no. There is no degree of fever that has been clearly associated with a specific risk of serious infection in patients. The exception to this may be in nonimmunized children; prior to the widespread use of the Haemophilus influenza vaccine, temperatures over 41.1 "C (105.98"F) were associated with a higher incidence of serious bacterial illness in children.

15. Prior to the approval of the pneumococcal conjugate vaccine in 2000, occult pneumococcal bacteremia was observed to be three times more likely in children with a fever of 39.5"C (103.1°F) or greater versus a fever of 39.0°C (102.2"F).

16. The best way to reduce a fever Most physicians use antipyretics for patients who are uncomfortable because of fever. Within the range of 40°C to 42"C, there is no evidence that fever is injurious to tissue. Use of antipyretics should be considered in pregnant women and patients with preexisting cardiac compromise who would not tolerate the increased metabolic demands of a fever.

17. Acetaminophen is the antipyretic of choice in most hospitals. Ibuprofen, other nonsteroidal anti-inflammatory drugs (NSAIDS), and aspirin are also effective. However, due to the association with Reye's syndrome, aspirin is usually not recommended for children.

18. Response to these agents is seen with both serious and benign causes of fever. Recurrence of fever after antipyretics wear off is often concerning for parents But it does not distinguish between serious and benign causes of fever, and base our concerns on the child's behavior rather than the height of the fever or its response to antipyretics.

19. Complementary methods, such as cool bathing and undressing the patient, are generally not felt to be effective at significantly lowering core body temperature and should be reserved as adjuncts for higher temperatures.

20. If the temperature is above 41.5"C (106.7"F) The diagnosis of hyperthermia should be considered and rapid cooling measures used if any concern about this condition exists.

21. Causes of fever First and foremost, at the top of the list is infection (both bacterial and viral). Infection causes the vast majority of fevers, but other causes must also be included in the differential diagnosis: Neoplastic diseases (e.g., leukemia, lymphoma, or solid tumors) Collagen vascular diseases (e.g., giant cell arteritis , polyarteritis nodosa , systemic lupus erythematosus , or rheumatoid arthritis)

22. Causes of fever Central nervous system lesions (e.g., stroke, intracranial bleed, or trauma) Illicit drug use (cocaine, ecstasy [MDMA], or methamphetamines) Withdrawal syndromes (delirium tremens or benzodiazepine withdrawal) Factitious fever Medications

23. Medications can cause fevers Any drug is capable of producing a drug fever; however, the most common culprits are penicillin and penicillin analogs . The fever usually begins 7 to 10 days after initiation of drug therapy. There is an associated rash or eosinophilia in about 20% of cases. Drug fever should always be a diagnosis of exclusion.

24. Key elements for Fever diagnosis

25. Pay particular attention to associated symptoms (e.g., cough, dysuria , diarrhea, or headache), duration of fever, ill contacts, history or risk of immunecompromise , and past medical history, particularly comorbid illnesses.

26. In the physical examination, note the general appearance of the patient, such as mild mental status changes or rashes that might be indicative of more serious systemic diseases.

27. In addition to a thorough routine physical examination, in appropriate cases a more detailed examination of the patient should be done to look for occult sites of infection, such as the nose/sinuses, rectum (i.e., prostatitis , perirectal abscess), and pelvic examination (i.e., pelvic inflammatory disease, tubo - ovarian abscess).

28. DRUGS COMMONLY ASSOCIATED WITH DRUG FEVERS

29. Antibiotics lsoniazid (INH) Nitrofurantoin Penicillins , cephalosporins Rifampin Sulfonamides Cardiac drugs Hydralazine Methyldopa Nifedipine Phenytoin Procainamide Quinidine Nonsteroidal anti-inflammatory drugs Ibuprofen Salicylates

30. Anticancer drugs Bleomycin Streptozocin Anticonvulsants Phenytoin Carbamazepine Others Barbiturates Cimetidine Iodides

31. Relationship between fever and tachycardia The pulse should increase about 10 beats per minute for each 0.6"C (1°F) increase in temperature. A pulse-temperature dissociation occurs when the patient has a fever but a heart rate that is lower than would be expected for the degree of fever. This dissociation occurs in typhoid, malaria, Legionnaires' disease, and mycoplasma .

32. Relationship between fever and tachycardia In early septic shock , tachycardia that is inappropriate for the degree of fever is often seen.

33. Relationship between fever and tachycardia Tachypnea out of proportion to fever is characteristic of Pneumonia and gram-negative bacteremia . Hypotension, particularly paired with tachycardia raises the concern of sepsis.

34. Do all septic patients have a fever? No, in fact, remember that within the definition of systemic inflammatory response syndrome (SIRS) is temperature greater than 38°C (104"F) or less than 36°C (96.8"F). Not all fevers are caused by infection, and not all infected patients have a fever.

35. Should everyone with a fever get antibiotics? Absolutely not. Antibiotic use should be based on the patient's specific presentation and diagnosis after an appropriate history and physical examination and directed laboratory and ancillary tests.

36. Most clinicians advocate giving antibiotics immediately to any patient who appears toxic or has suspected bacterial meningitis, without delaying for results of ancillary test or culture results. Other patients who should be considered for early antibiotics are Immuneoc-ompromised patients and elderly patients.

37. Neutropenic fever In patients with neutropenia (an absolute neutrophil count below 1,000 per square mm), A single temperature above 38.3"C (100.9"F) is considered a fever, and fever in these patients is secondary to infection until proven other-wise.

38. Neutropenic fever The risk of severe sepsis and septicemia is higher in these patients, and this initial workup should include screening for all sources of infection . Initial studies should include, at a minimum, a cell count and differential, metabolic panel, blood cultures, chest radiograph, and urinalysis; All these patients should receive antibiotics .

39. Fever of unknown origin (FUO) A fever greater than 38.3"C (100.9"F) documented on several occasions during a period longer than 3 weeks, with an uncertain diagnosis after 1 week of evaluation in the hospital. The most common cause of FUO is occult infection (particularly tuberculosis ) and malignancy Each accounting for approximately 30% of cases.

40. For how long do typical febrile illnesses last? In most cases, the fever resolves within 3 to 7 days.

41. Is a fever a friend or foe? Although fever per se is self-limiting and rarely serious, it is often considered by patients and doctors to be a major and harmful sign of illness, and parents and medical practitioners may develop what has been termed fever phobia, treating the fever almost as an illness in itself rather than a symptom.

42. More and more research is proving, however, that fever may be beneficial in fighting some infections. Higher Tempertures increase the activity of neutrophils and lymphocytes and decrease the levels of serum iron , a substrate that many bacteria need to reproduce.

43. It enhances immunological processes, including the activity of IL-1, T helper cells and cytolytic T cells, and B cell and immunoglobulin synthesis.

44. Alternating acetaminophen and ibuprofen for fevers. Is this effective? This is not an evidence-based practice. There is presently no scientific evidence that this combination is safe or achieves faster antipyresis than an adequate dose of either agent alone.

45. The observed fever reduction of 0.5"C when combining antipyretics, Compared with a single antipyretic, is insufficient to warrant routine use. Additionally, alternating antipyretics can be confusing for caregivers, potentially leading to incorrect dosing of either product. The practice can also increase parents' fever phobia because it increases parental preoccupation with the height of the fever.

46. Global Critical Care https://www.facebook.com/groups/1451610115129555/#!/groups/1451610115129555/ Wellcome in our new group ..... Dr.SAMIR EL ANSARY

47. GOOD LUCK SAMIR EL ANSARY ICU PROFESSOR AIN SHAMS CAIRO [email protected]