Infectious Disease

Because it is commonly recommended that no surgery except emergency or essential surgery (e.g., drainage of an abscess) be performed when an acute infectious disease is present and because renal insufficiency can be caused by antimicrobial drugs,^{[684] [689] [690]} renal function and organ damage from renal insufficiency should be assessed preoperatively when infectious disease is present. Prophylactic administration of antibiotics (see Table 27-37 and Table 27-38 ) helps prevent sepsis from bacteremic interventions.^{[734] [735]}

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Sepsis is a leading cause of postoperative morbidity,^{[685] [686] [690] [691]} probably through a decrease in systemic vascular resistance related to activation of the complement system and other mediators. Thus, attention to the effects of antibiotic drugs must be supplemented by attention to intravascular volume status. ^{[688] [689] [690] [691] [737] [738]} The degree of impairment of the infected organ and its effect on anesthesia should be assessed. For instance, endocarditis merits examination of volume status; antibiotic and other drug therapy and side effects^[739] ; myocardial function; and renal, pulmonary, neurologic, and hepatic function—organ systems that can be affected by endocarditis.

Although all surgery except emergency or essential operations is proscribed when an acute infectious disease is present^{[549] [550] [551] [552] [553] [554] [555] [556] [557] [558] [559] [560] [561] [567] [568] [569] [570] [571] [740]} (also see the section on upper respiratory infections in the pulmonary section of this chapter), many such diseases (e.g., influenza and pneumococcal pneumonia) are becoming less frequent because of successful immunization recommendations and programs. ^{[741] [742]} Whether the preoperative clinic can or should be used to increase the use of preventive vaccines is currently being studied, but it is unclear whether vaccination in the 48 hours before surgery is effective or risky.^[743] Furthermore, even though acute infections are less common, surgery in patients with chronic viral diseases such as hepatitis and HIV is more frequent. Many of these patients may also harbor opportunistic infections

TABLE 27-48 -- Types and causes of hypotonic hyponatremia *

Hypovolemic

Gastrointestinal losses

Vomiting

Diarrhea

Skin losses

Third-space losses

Lung losses

Renal losses

Diuretics

Renal damage

Urinary tract obstruction

Adrenal insufficiency

Isovolemic

Syndrome of inappropriate secretion of antidiuretic hormone

Renal failure

Water intoxication

Hypokalemia

Dysfunctional osmostat

Hypervolemic

Congestive heart failure

Nephrosis

Liver dysfunction

*Serum osmolality less than 280 mOsm/L.

At least two other considerations merit preoperative consideration: patient isolation to prevent contamination of the patient and health care providers. Both concerns are real and are the focus of at least several published volumes. Nosocomial infection is a major source of post-surgical morbidity.^{[745] [746] [747] [748] [749] [750] [751]} Acquired immunodeficiency syndrome (AIDS)^[752] and many forms of hepatitis (A, B, and C) appear to be due to viral infections but require direct contact with blood or body fluids. Screening for specific viruses or for the chronic end-organ effects of these viruses^{[753] [754] [755]} is now being done to reduce the risk of infection to both recipients and health care personnel during blood transfusions. The usual precautions appear to be largely effective, ^[756] but the risk is considerable if these precautions are not followed meticulously.^[757]