The management of postoperative infection∗

The Management

of Postoperative

Infection*

HOBART A. REIMANN, M.D. Philadelphia,

Pennsylvania

T

HE PREVENTION of postoperative infection would preclude the need for its treatment. It seems unnecessary to re-emphasize the importance of postponing elective operations in patients with minor infections of the respiratory tract. The hazards of “hospital” staphylococcal infections and means for their prevention also are too well known to be detailed here. Serum hepatitis may be a postoperative infection, although its onset is delayed for months. Diabetes, cirrhosis, cardiovascular-renal and other chronic diseases must be controlled preoperatively as far as possible. It is better to enhance the natural resistance of the patient than to rely solely on antimicrobic prophylaxis and therapy that may have reached their limits of usefulness.

carbolic spray of a former generation ;” L to this may be added the sprinkling of sulfonamides in wounds. “Indeed in the present climate of opinion it may seem vain to preach the truths that trivial infections do not require antibiotics, that clean operations can be done without antibiotic cover.“2 “If we were not so often and so uncritically anxious to do a bacteriological good deed where none is required, we should be far less likely to spread harm of a kind that it This may soon prove impossible to control.” critique made 9 years ago was sound. Furthermore, “as many lives may be lost by the indiscriminate use of antimicrobics as by failure to use them when they are needed.” “Repeated warnings of the danger of toxic and allergic reactions, superinfections and increasing microbic resistance have been given so often by so many authorities that exhortations are wearying to those that heed them.“3 Evidence of infection may be masked by antimicrobic agents,4 and their use may give a false sense of security. As will be outlined, antimicrobic prophylaxis has its place in certain conditions,5 but even then it has failed to decrease the incidence of infections unless hemolytic streptococci or pneumococci were the cause. The combination of penicillin and streptomycin often is used routinely in the blind belief that it reduces the These incidence of postoperative infections. have not been reduced, and those that occurred were caused mainly by resistant staphylococci or gram-negative bacilli. The kind of infecting bacteria has changed without diminishing the number of infections. Prophylactic therapy has failed in both “clean” and potentially contaminated areas. The infection rate was 5 per cent in 1958, the same as it was 20 years ago.6 According to one observer, the rate of infections after surgical operations is higher in patients treated routinely with antimicrobics than in Nitrofurantoin has failed to untreated ones.7 reduce the incidence of infection after pros-

PROPHYLAXIS Gentle aseptic surgical manipulation consistent with the speed of operation, minimal trauma to tissues and restraint in the use of binders, casts, transfusions, drugs, clyses, aspirations, catheters and intubations are essential to preventing For bedridden patients frequent infections. change of position and breathing exercises tend to prevent pulmonary atelectasis that favors Prolonged narcosis should pulmonary infection. be avoided since it increases the danger of inspiration of vomitus or other material. Further, because postoperative patients whether debilitated or not are subject to infection with staphylococci and other microbes, patients with staphylococcal infections should be isolated in separate quarters. Personnel who have minor staphylococcal lesions or are known disseminators of these microbes should not attend wounded or severely burned patients, or those under surgical treatment. ANTIMICROBICAGENTS According to editorial comment, “the present day custom to use antimicrobial prophylaxis for clean surgical wounds has become heir to the

* From the Department of Medicine and Preventive Medicine, The Hahnemann Medical College and Hospital, Philadelphia, Pa. 470

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FIG. 1. Survey of nearly 7,000 necropsy protocols from New England Deaconess Hospital starting in 1928. Graph shows incidence of deaths from infections in four periods: (1) no antibacterial, (2) sulfa, (3) antimicrobic to 1955 and (4) since 1955 (Fosterj I3 Thr incidence in 1957 equaled that of 1941.

Preoperative prophylaxis with tatectomy.8 penicillin failed to prevent pulmonary infection9 Antimicrobic therapy has been blamed for the present high incidence of puerperal sepsis with a death rate of 50 per cent when Pseudomonas was the cause.l’) The majority of postoperative deaths in the preantimicrobic era was caused by “shock”; in after years, infection chiefly was responsible. According to Clark and Hanson,” an increase in the mortality rate from severe burns between 1947 and 1956 was from deaths caused mainly by previously innocuous bacteria. The number of infections in clean wounds caused by penicillin-resistant staphylococci also has increased.‘* Figure 1, prepared by Foster,i3 graphically portrays the changed incidence of postoperative infections before and during the antimicrobic Almost identical statistics covering the era. same period were published by Barnes et a1.r4 The decline in the number of infections between 1941 and 1954 was attributed to better preoperative care involving the regulation of fluid balance and electrolytes, proper diet and to antimicrobics and transfusions of blood when For a number of reasons, the rate of needed. infection rose between 1954 and 1957 to a degree as high as it was in 1941. OCTOBER

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Lest antimicrobic therapy and environmental circumstances be overly condemned, other factors also are blamed for the recent increase in the incidence of postoperative infections. Advances of technic and equipment made possible many more urgent operations and hazardous ones in heretofore restricted areas. The increased proportion of aged patients in the population who need surgical treatment also is a factor. The impairment of resistance to infection during therapy with radiation, corticosteroids and other powerful drugs, and the increased number of diagnostic aspirations and biopsies, intubations, clyses, transfusions and tracheotomies are factors that contribute to the incidence of postoperative infections. Indications: Antimicrobic prophylaxis is indicated when a preoperative infection caused by a specific microbe sensitive to the drugs is present. Prophylaxis also is recommended (1) before, during and after operations in contaminated fields in the abdomen, thorax, urogenital tract and oropharynx; (2) for severe burns; (3) for wounds of violence after debridement, compound fractures, penetrating wounds of the abdomen and thorax; (4) after urgent operations when a known bacterial infection exists ; (5) for patients with cardio-

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valvular defects; and (6) in aged persons with pre-existing pulmonary disease.4s15 For severe burns, penicillin injected parenterally after the first postburn week and the local application of bacitracin or polymyxin B are advocated to prevent infection. If resistant pathogens are involved, different parenterally injected antimicrobic agents are needed. Because two thirds of fatal burn infections are caused by Pseudomonas or Proteus bacilli, early closure of a wound is needed. Details of preventive treatment were outlined by Altemeier.16 Antimicrobic prophylaxis is not recommended for viral respiratory tract infections, nor when indwelling catheters are in place, unless infection with known bacteria exists. There are no means available at present to prevent postoperative serum hepatitis except by the use of sterile instruments and the infusion of virusfree blood or plasma. Diagnosis of Postoperative Infection: The physician who manages postoperative infection should be familiar with the kind of operation that had been performed ; the anesthetic used ; if excessive bleeding, shock or vomiting had occurred; if necrotic or malignant tissue had not been removed ; and if the operation were performed in an infected area. Knowledge of the preoperative bacteriologic state is needed, that is, if known microbes were the cause of abscess, osteomyelitis, pelvic inflammatory disease, bronchiectasis, pyelonephritis and other infections. It is well to be informed of the patient’s personality, the existence of other chronic disease, and if prior therapy with antimicrobics, corticosteroids or radiation had been applied. Of prime importance is the early recognition of postoperative infection by close observation and repeated physical examination. Fever provoked by injured tissue often follows surgical procedures, but it should not be regarded as “normal” if it lasts longer than 48 hours. Fever also occurs during severe dehydration, as a toxic or hyperergic reaction to drugs, from a hematoma, phlebitis or a pre-existing infection. On the other hand, fever may be suppressed deceptively by antipyretic, sedative, antimicrobit or corticosteroid drugs. The existence of postoperative infection is likely if the patient fails to recover as expected, and if anorexia, restlessness, undue mental depression or confusion persist or appear. Tachycardia, tachypnea, sweating, chilliness, diarrhea, vomiting Leukocyte and leukocytosis suggest infection.

counts, cultures of the blood, and appropriate done promptly. SPECIFIC

wound, exudates and skiagraphy should be

TREATMENT

In the selection of an antimicrobic agent, too much reliance should not be placed on bacteriologic reports. Microbes isolated from a wound or exudate may be commensals not involved in the infection. “Sensitivity” tests may be misleading ; their results are important if they show high sensitivity or great resistance. Clinical judgment is needed. If the pathogen is identified, prompt treatment with the appropriate drug in adequate amount and for a duration is mandatory. Doses too proper small are ineffective, and too large ones are wasteful. Cure cannot be expected in a few hours. If, however, improvement fails after three days, perhaps the wrong agent was used or the diagnosis may be wrong. Infection in an inaccessible abscess or in dense tissue requires surgical intervention. Increasing the dose of antimicrobic agents to huge amounts, or their persistent use, or rapidly substituting one agent for another, or giving combinations of drugs usually is futile. At times it may be necessary to give an antimicrobic agent empirically while awaiting bacteriologic diagnosis. If the report then indicates a wrong selection, the proper drug can be substituted. In all cases, a quick-acting drug, not repository preparations, is needed. Intramuscular or intravenous injection is preferred to oral ingestion. Inquiry is needed to determine what antimicrobic agent, if any, had been given previously ; if evidence of hypersensitivity occurred, a different agent should be used. The skin test is unreliable to detect hypersensitivity; yet for legal reasons it should be done. Penicillin is the Choice of Antimicrobic Agent: drug of choice for infections with hemolytic streptococci, pneumococci, Clostridium tetani and sensitive staphylococci. These bacteria have become rare as causes of postoperative infections For and have been replaced by resistant ones. penicillin-resistant staphylococci, methicillin, oxacillin, vancomycin or novobiocin are effective. For grossly contaminated lesions containing a variety of microbes none of which can be specifically incriminated, tetracycline or chloramphenicol in doses of 500 mg. intravenously every eight to twelve hours for at least seventy-two hours is recommended. This is THE AMERICANJOURNAL

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one of the few circumstances

wherein penicillin also should be injected in amount of 1 million units (600 mg.) at the same intervals. For infections resistant to therapy with antimicrobic agents usually given parenterally, more toxic ones like neomycin, polymyxin or bacitracin may be tried cautiously by parenteral routes in desperate cases. Colistimethate sodium (ColyMycinQ) is said to be effective against many gram-negative bacilli. Topical application seldom is indicated, and its value is doubtful. Antimicrobic treatment Duration of Therapy: should be continued until fever abates and The dosage clinical improvement is obvious. then should gradually be diminished and discontinued after several days to a week, depending upon circumstances. Therapy prolonged For all patients for weeks or months is useless. treated with antimicrobic agents, the intake and excretion of fluids must be regulated ; examination of the blood, urine, mucous membranes and skin must be made at intervals to detect any evidence of toxic or hyperergic reactions. “Drug fever” may confuse diagnosis. Symptomatic Treatment: Distinctive postoperative infections such as pneumonia, cystitis and hepatitis need special symptomatic treatment as well. Tracheotomy and suction are needed only if obstructive exudate cannot be aspirated by means of tubes inserted through the mouth or nares. Urethral catheters should be employed Sore throat only if necessary, never routinely. often is induced by the irritation of indwelling tubes. Postoperative diarrhea caused by the presence of staphylococci induced by broad spectrum antimicrobic therapy usually stops If not, specific when the drug is discontinued. agents are indicated. “REFRACTORY HYPOTENSION” The term refractory hypotension is preferable to irreversible shock for this postoperative condition. In a study of 14 victims more than 60 years of age, appropriate treatment failed in only 3. Infection with a variety of bacteria, predominantly gram-positive, played a role in 6, but there was no proof that exo- or endotoxins Adrenal insufficiency was not were implicated. evident as a cause of hypotension, and corticosteroids were ineffective in its correction.i7 In another study, 67 per cent of patients, rendered hypotensive by gram-negative bacillary infection, also were more than 60 years old and two thirds of them recovered. Most deaths were from other causes. Bacterial invasion OCTOBER1963

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seemed to be a terminal event. Unlike the features of shock from other causes, the skin may be flushed, the pulse bounding, and fever and alertness may be present.18 Biochemical, anatomic and microbic factors in Hypotension results combinations are at fault. from a deficient volume of blood, hyponatremia or acidosis or both, cardiac failure, local vascular injuries of extensive operations and severe infection. Each of these factors requires appropriate treatment controlled by constant monitoring of the venous pressure, the hourly output of urine, the color of the skin and the flow of blood in capillaries. Insufficient replacement of fluids or blood does little good, and too much is dangerous.‘9 Vasopressor agents are not curative but serve to improve blood pressure for a short time during the critical period while the underlying defects are being rectified. l7 Huge doses or combinations of antimicrobic agents are not needed when infection plays no role in postoperative refractory hypotension. SUMMARY

The incidence of postoperative infections decreased after 1941 and reached a low level until 1954. The incidence then began to increase and approach that of the preantimicrobic era. Many factors besides the use and misuse of antimicrobics are responsible. The incidence probably cannot be reduced greatly because of the hazards of operations now performed in vital areas, and the extensive use of antimicrobic corticosteroids and other powerful agents, Improvement can be attained by agents. careful preoperative, operative and postoperative management. Clyses, aspirations, intubations, transfusions, binders, drugs, sedatives and tracheotomy should be applied with restraint and only when necessary. Routine prophylaxis with antimicrobic agents is condemned, but the drugs are effective in instances wherein specific agents can be applied against The failure of treatment of sensitive microbes. the increasing number of infections caused by resistant bacteria, previously of little importance, Antimicrobic provides a problem to be solved. therapy even when appropriate may fail when the natural mechanism of defense against inEnhancement of resistance fection is impaired. is equal in importance to drug therapy. REFERENCES 1. Fortmitdem

Spray!

Lancet, 1: 1845,1956.

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2. Antibiotic-resistant staphylococci (Editorial). Lancet, 2: 1003, 1954. 3. Antibiotic-resistant staphylococci, (Editorial). Lancet, 1: 790, 1956. 4. ALTEMEIER,W. A. A current evaluation of the antibiotics in surgery. Postgrad. Med., 20: 319, 1956. 5. MELENEY, F. and JOHNSON,B. A. Rational use of antibiotics in the control of surgical infections. J.A.M.A., 153: 1253, 1953. 6. SANCHEZ-UBEDA,R., FTRNAND, E. and ROUSSELOT, L. M. Complication rate in general surgical cases; the value of penicillin and streptomycin as postoperative prophylaxis; a study of 511 cases. New England J. Med., 259: 1045, 1958. 7. KAPP, D. F. .4ntibiotic prophylaxis in unpredictable infection; a medical &l surgical fallacy. Guthrie Clin. Bull.. 26: 165, 1957. 8. ORR, L. M., DANIEL, W. g., CAMPBELL,J. L. and THORNLEY, M. W. Effect of nitrofurantoin (Furadantin) on morbidity after transurethral resection. J.A.M.A., 167: 1455, 1958. 9. GRIFFITHS,E. Failure of penicillin to prevent postoperative chest infection. Brit. M. J., 1: 803,1957. 10. HODGES, R. M. and DE ALVAREZ, R. R. Puerperal septicemia and endocarditis caused by Pseudomonas aeruginosa. J.A.M.A., 173: 1081, 1960. 11. CLARK, A. G. and HANSON,J. H. Mortality rates in patients with burns; a report of experience at

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San Francisco City and County Hospital, 1943-56. California Med., 89: 210, 1958. HOWE, C. W. Postoperative wound infections due to staphylococcus aureus. New England J. Med., 251: 411, 1954. FOSTER, F. P. An internist’s responsibility in anticipation, detection and treatment of surgical infections. Surp. Clin. North America, 40: 793, 1960. BARNES,B. A., BEHRINGER,G. E., WHEELOCK,F. C., WILKINS, E. W. and COPE, 0. Surgical sepsis; J.A.M.A., report on subtotal gastrectomies. 173: 1081, 1960. ALTEMEIER,W. A. and WULSIN, J. H. Antimicrobial therapy in injured patients. J.A.M. A., 173 : 527, 1960. ALTEMEIER,W. A., MACMILLAN, B. G. and HILL, E. 0. Antibiotic therapy for severe burns. Surgery, 52: 240, 1962. SMITH, L. L., and MOORE, F. D. Refractory hypotension in man-is this irreversible shock? New England J. Med., 267: 733, 1962. MARTIN, W. J. and MCHENRY, M. C. Fifty-nine cases of bacteremic shock due to gram-negative M. Clin. North America, 46: 1073, enteric bacilli. 1962. BOWERS, P. A. and LINDQUIST,J. N. Preoperative Clin. and postoperative medical complications. Obst. &3 Gym., 5: 579, 1962.

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