Showing papers in "Survey of Anesthesiology in 1992"

The Timing of Prophylactic Administration of Antibiotics and the Risk of Surgical-Wound Infection

Abstract: Background. Randomized, controlled trials have shown that prophylactic antibiotics are effective in preventing surgical-wound infections. However, it is uncertain how the timing of antibiotic administration affects the risk of surgical-wound infection in actual clinical practice. Methods. We prospectively monitored the timing of antibiotic prophylaxis and studied the occurrence of surgical-wound infections in 2847 patients undergoing elective clean or "clean—contaminated" surgical procedures at a large community hospital. The administration of antibiotics 2 to 24 hours before the surgical incision was defined as early; that during the 2 hours before the incision, as preoperative; that during the 3 hours after the incision, as perioperative; and that more than 3 but less than 24 hours after the incision, as postoperative. Results. Of the 1708 patients who received the prophylactic antibiotics preoperatively, 10 (0.6 percent) subsequently had surgical-wound infections. Of the 282 patients who recei...

A Prospective Study of Indexes Predicting the Outcome of Trials of Weaning from Mechanical Ventilation

Abstract: Background. The traditional predictors of the outcome of weaning from mechanical ventilation — minute ventilation (VE) and maximal inspiratory pressure (P1max) — are frequently inaccurate. We developed two new indexes: the first quantitates rapid shallow breathing as the ratio of respiratory frequency to tidal volume (f/VT), and the second is termed CROP, because it integrates thoracic compliance, respiratory ṟate, arterial oxygenation, and P1max. Methods. The threshold values for each index that discriminated best between a successful and an unsuccessful outcome of weaning were determined in 36 patients, and the predictive accuracy of these values was then tested prospectively in an additional 64 patients. Sensitivity and specificity were calculated, and the data were also analyzed with receiver-operating-characteristic (ROC) curves, in which the proportions of true positive results and false positive results are plotted against each other for a number of threshold values of an index; the area...

Inhaled Nitric Oxide as a Cause of Selective Pulmonary Vasodilatation in Pulmonary Hypertension

Abstract: The acute effects of inhaled nitric oxide (NO) (40 ppm in air) on pulmonary (PVR) and systemic (SVR) vascular resistance were compared with those of an intravenous infusion of prostacyclin (24 micrograms/h) in 8 patients with severe pulmonary hypertension and 10 cardiac patients with normal values of PVR. 10 healthy volunteers were studied non-invasively. In the patients with pulmonary hypertension, PVR fell significantly after inhaled NO and after prostacyclin. PVR also fell significantly in the cardiac patients after inhaled NO. Although SVR fell substantially after prostacyclin in patients with pulmonary hypertension, inhaled NO had no effect on SVR in any patient or volunteer. Inhaled NO therefore seems to be both a selective and effective pulmonary vasodilator.

Hepatitis C Virus Infection in Post-Transfusion Hepatitis: An Analysis with First- and Second-Generation Assays

Abstract: Background. The causes of post-transfusion non-A, non-B hepatitis are still not fully defined, nor is it clear how accurate the tests are that are used to screen blood donors for hepatitis C virus (HCV) and to diagnose post-transfusion hepatitis caused by infected blood. Methods. We used two first-generation enzyme-linked immunoassays (ElAs) and one second-generation immunoassay to test for anti-HCV antibodies in serum samples collected between 1976 and 1979 in the Transfusion-Transmitted Viruses Study (from 1247 patients who underwent transfusion and 1235 matched control subjects who did not receive transfusions). We tested serum collected before and after infection from the patients in whom non-A, non-B hepatitis developed, serum from their blood donors, and serum from 41 of the control subjects who had hepatitis unrelated to transfusion. Results. Of the 115 patients in whom post-transfusion non-A, non-B hepatitis developed, the initial serum samples of 111 were anti-HCV-negative; after hepatit...

Inhaled Nitric Oxide: A Selective Pulmonary Vasodilator Reversing Hypoxic Pulmonary Vasoconstriction

Abstract: Background. The gas nitric oxide (NO) is an important endothelium-derived relaxing factor, inactivated by rapid combination with heme in hemoglobin. Methods and Results. Awake spontaneously breathing lambs inhaled 5-80 ppm NO with an acutely constricted pulmonary circulation due to either infusion of the stable thromboxane endoperoxide analogue U46619 or breathing a hypoxic gas mixture. Within 3 minutes after adding 40 ppm NO or more to inspired gas, pulmonary hypertension was reversed. Systemic vasodilation did not occur. Pulmonary hypertension resumed within 3-6 minutes of ceasing NO inhalation. During U46619 infusion pulmonary vasodilation was maintained up to 1 hour without tolerance. In the normal lamb, NO inhalation produced no hemodynamic changes. Breathing 80 ppm NO for 3 hours did not increase either methemoglobin or extravascular lung water levels nor modify lung histology compared with control lambs. Conclusions. Low dose inhaled NO (5-80 ppm) is a selective pulmonary vasodilator reversing both hypoxia- and thromboxane-induced pulmonary hypertension in the awake lamb [corrected].

Prevention of High-Altitude Pulmonary Edema by Nifedipine

Abstract: BACKGROUND Exaggerated pulmonary-artery pressure due to hypoxic vasoconstriction is considered an important pathogenetic factor in high-altitude pulmonary edema. We previously found that nifedipine lowered pulmonary-artery pressure and improved exercise performance, gas exchange, and the radiographic manifestations of disease in patients with high-altitude pulmonary edema. We therefore hypothesized that the prophylactic administration of nifedipine would prevent its recurrence. METHODS Twenty-one mountaineers (1 woman and 20 men) with a history of radiographically documented high-altitude pulmonary edema were randomly assigned to receive either 20 mg of a slow-release preparation of nifedipine (n = 10) or placebo (n = 11) every 8 hours while ascending rapidly (within 22 hours) from a low altitude to 4559 m and during the following three days at this altitude. Both the subjects and the investigators were blinded to the assigned treatment. The diagnosis of pulmonary edema was based on chest radiography. Pulmonary-artery pressure was measured by Doppler echocardiography and the difference between alveolar and arterial oxygen pressure was measured in simultaneously sampled arterial blood and end-expiratory air. RESULTS Seven of the 11 subjects who received placebo but only 1 of the 10 subjects who received nifedipine had pulmonary edema at 4559 m (P = 0.01). As compared with the subjects who received placebo, those who received nifedipine had a significantly lower mean (+/- SD) systolic pulmonary-artery pressure (41 +/- 8 vs. 53 +/- 16 mm Hg, P = 0.01), alveolar-arterial pressure gradient (6.6 +/- 3.8 vs. 11.8 +/- 4.4 mm Hg, P less than 0.001), and symptom score of acute mountain sickness (2.0 +/- 0.7 vs. 3.9 +/- 1.9, P less than 0.01) at 4559 m. CONCLUSIONS The prophylactic administration of nifedipine is effective in lowering pulmonary-artery pressure and preventing high-altitude pulmonary edema in susceptible subjects. These findings support the concept that high pulmonary-artery pressure has an important role in the development of high-altitude pulmonary edema.

Postoperative Epidural Morphine is Safe on Surgical Wards

Abstract: The use of epidural morphine for postoperative analgesia outside of intensive care units remains controversial. In this report our anesthesiology-based acute pain service documents experience with 1,106 consecutive postoperative patients treated with epidural morphine on regular surgical wards. This experience involved 4,343 total patient days of care and 11,089 individual epidural morphine injections. On a 0-10 verbal analog scale, patient-reported median pain scores at rest and with coughing or ambulation were 1 (inter-quartile range 3) and 4 (interquartile range 4), respectively. The incidence of side effects requiring medication were as follows: pruritus 24%, nausea 29%, and respiratory depression 0.2%. There were no deaths, neurologic injuries, or infections associated with the technique. Migration of epidural catheters into the subarachnoid space and into epidural veins each occurred twice. Overall, 1,051 of the 1,106 patients (95%) experienced none of the following problems: catheter obstruction, premature dislodgement, painful injections, catheter migration, infection, or respiratory depression. We conclude that postoperative pain can be safely and effectively treated with epidural morphine on surgical wards.

The Effect of Muscle-Sparing Versus Standard Posterolateral Thoracotomy on Pulmonary Function, Muscle Strength, and Postoperative Pain

Abstract: Increased interest in alternative approaches to thoracotomy has developed because of the considerable morbidity associated with the standard posterolateral technique. We conducted a prospective, randomized, blinded study of 50 consecutive patients to compare postoperative pain, pulmonary function, shoulder strength, and range of shoulder motion between the standard posterolateral and the muscle sparing thoracotomy techniques. Pulmonary function (forced expiratory volume in 1 second and forced vital capacity), shoulder strength, and range of motion were measured preoperatively and at 1 week and 1 month postoperatively. Pain was quantitated by postoperative narcotic requirements, the visual analogue scale, and the McGill pain questionnaire. Morbidity, mortality, and hospital stay were compared between the standard posterolateral and muscle-sparing techniques. There were no differences in postoperative pulmonary function, shoulder range of motion, extent of lung resection, surgical approach time, mortality, or hospital stay. There was significantly less postoperative pain in the muscle-sparing group. The narcotic requirement was less in the first 24 hours (p = 0.0169), and visual analogue scale scores were significantly lower (p

Influence of Age on Atelectasis Formation and Gas Exchange Impairment During General Anaesthesia

Abstract: We have studied the effects of anaesthesia on atelectasis formation and gas exchange in 45 patients of both sexes, smokers and non-smokers, aged 23–69 yr. None of the patients showed clinical signs of pulmonary disease, and preoperative spirometry was normal. In the awake patient, partial pressure of arterial oxygen (PaO2) decreased with increasing age (P

Coagulation Profile in Severe Preeclampsia

Abstract: One hundred women with severe preeclampsia or chronic hypertension with superimposed preeclampsia were seen during a 2-year period. We sought to determine whether a normal platelet count assures that no other clinically significant clotting abnormalities are present, and what level of thrombocytopenia predicts a risk of abnormalities in other coagulation indices. Fifty women had platelet counts below 150,000/microL, of whom 13 had a fibrinogen level below 300 mg/dL and two had a prolonged prothrombin time (PT) or partial thromboplastin time (PTT). The admission platelet count was an excellent predictor of subsequent thrombocytopenia (r = 0.829, P less than .001). No subject had an abnormal fibrinogen level or prolonged PT or PTT in the absence of thrombocytopenia. When monitoring intrapartum coagulation indices in preeclampsia, one can safely follow only the platelet count at admission and subsequently, reserving PT and PTT and fibrinogen levels for those cases complicated by counts less than 100,000/microL.

Changes over Time in the Knowledge Base of Practicing Internists

Abstract: OBJECTIVE To determine factors affecting the knowledge base of practicing internists. DESIGN An 82-item multiple-choice examination with questions from the 1988 American Board of Internal Medicine (ABIM) certifying examination was used to assess the knowledge base of 289 internists. SETTING AND PARTICIPANTS Participants were selected from among practicing internists in New York, New Jersey, and Pennsylvania who had received ABIM certification 5 to 15 years previously. RESULTS significant inverse correlation (r = -.30) was found between examination scores and the number of years elapsed since certification. Knowledge declined sharply within 15 years of certification. In addition, procedure-oriented subspecialists (cardiologists and gastroenterologists) had lower scores than other internists in this examination of general medical knowledge. Multivariate analyses showed that independent variables that predicted test performance were initial ABIM certifying examination score, time elapsed since certification, subspecialty classification, medical school type, and residency type. CONCLUSIONS These results support the recent decision for time-limited certification of internists and raise questions related to content and standard setting for recertification examinations.

The Addition of 0.2 mg Subarachnoid Morphine to Hyperbaric Bupivacaine for Cesarean Delivery: A Prospective Study of 856 Cases

Abstract: In an effort to determine the incidence of respiratory depression and other side effects of subarachnoid morphine, we conducted the following prospective study in a large number (856) of young female patients undergoing cesarean delivery in one hospital. During the period from July 1987 to January 1989, patients receiving subarachnoid hyperbaric bupivacaine combined with 0.2 mg preservative-free morphine were included. They were continuously monitored for 24 hours using a pulse oximeter. For 24 hours, the vital signs, including respiratory rate every hour, and the side effects, including pruritus, nausea, and vomiting, were recorded. The need for analgesia and the total dose of opioids during the first 24 hours were documented. Our results showed that respiratory depression (SaO2 ≤ 85% and/or respiratory rate ten breaths per minute or less) occurred in eight patients, all of whom were markedly obese. Fifty-eight percent of the patients did not require analgesics for 24 hours. In those requiring an added opioid, the dose was (9.1 ± 0.5 mg morphine, mean ± SEM). Eighty-five percent of the patients were satisfied with the postoperative analgesia. Six percent were dissatisfied due to the side effects, i.e., pruritus, nausea and/or vomiting. Nine percent were dissatisfied with the pulse oximeter because it caused false alarms and limited their mobility.

Operative Procedures Not Involving the Heart After Percutaneous Transluminal Coronary Angioplasty

Abstract: The benefit of coronary artery bypass grafting (CABG) in patients with coronary artery disease (CAD) who require extensive surgical procedures not involving the heart has been established. During the past decade, percutaneous transluminal coronary angioplasty (PTCA) has been developed as an alternative therapy to CABG for patients with CAD. In an attempt to determine the safety of other surgical procedures after PTCA, we retrospectively reviewed 148 patients who underwent 193 surgical procedures from four to 1,867 days after PTCA for CAD. Seventy-two patients had surgical treatment within 90 days of PTCA. Thirty-five patients had CABG prior to PTCA, and 113 had PTCA as the initial treatment for CAD. Four patients died postoperatively, only one death was cardiac in origin. One patient had a myocardial infarction postoperatively (the one cardiac death). Fifteen patients had other cardiac complications (nine patients with arrhythmias and six with myocardial ischemia). Patients operated upon within 90 days of PTCA had no increased cardiac morbidity, although the one myocardial infarction occurred in this group. No difference in cardiac morbidity occurred in patients with multivessel CAD treated by PTCA compared with single vessel disease. However, patients more than 60 years of age had more cardiac problems (16 of 110) than those less than 60 years of age (zero of 38) (p = 0.01). Treatment of CAD by PTCA protects the myocardium from fatal cardiac events and myocardial infarction during subsequent noncardiac operative procedures even early (less than 90 days) in the post-PTCA period. Older patients seem to be at higher risk, however, for nonfatal cardiac complications.

Comparison Between Sevoflurane and Halothane for Pediatric Ambulatory Anesthesia

Abstract: We have compared the rapidity and quality of recovery after sevoflurane anaesthesia with those after halothane anaesthesia. Thirty unpremedicated paediatric outpatients undergoing pulsed-dye laser therapy for port-wine stains were allocated randomly to receive either halothane or sevoflurane anaesthesia. Each group received 60% nitrous oxide and 1.0-1.5 MAC of volatile agent in oxygen for approximately 40 min. Patients receiving sevoflurane exhibited more rapid emergence and a significantly shorter postoperative recovery time compared with those receiving halothane. No major adverse effects were encountered in each group. These results suggest that sevoflurane anaesthesia is preferable to halothane anaesthesia for paediatric ambulatory patients.

Cardiovascular Responses to Insertion of the Laryngeal Mask

Abstract: We have compared, in 40 healthy patients, the cardiovascular responses induced by laryngoscopy and intubation with those produced by insertion of a laryngeal mask. Anaesthesia was induced with thiopentone and maintained with enflurane and nitrous oxide in oxygen; vecuronium was used for muscle relaxation. Arterial pressure was measured with a Finapres monitor. The mean maximum increase in systolic arterial pressure after laryngoscopy and tracheal intubation was 51.3% compared with 22.9% for laryngeal mask insertion (p less than 0.01). Increases in maximum heart rate were similar, (26.6% v 25.7%) although heart rate remained elevated for longer after tracheal intubation. We conclude that insertion of the laryngeal mask airway is accompanied by smaller cardiovascular responses than those after laryngoscopy and intubation and that its use may be indicated in those patients in whom a marked pressor response would be deleterious.

Hemodynamic Effect of the Prone Position During Anesthesia

Abstract: We studied 21 patients undergoing lumbar spinal surgery under halothane anesthesia on a convex saddle frame, in order to determine the hemodynamic effect of the prone position. A thermodilution pulmonary arterial catheter was placed in 14 patients (Group PA-1: n = 8; and Group PA-2: n = 6), and an inferior vena caval catheter in the remaining seven patients (Group IVC). Group PA-1 and Group IVC patients were placed in the prone position on a convex saddle frame. In the prone position, the cardiac index (CI) decreased significantly from 3.1 +/- 0.5 to 2.5 +/- 0.3 (l.min-1.m-2, mean +/- s.d., P less than 0.01) without accompanying significant changes in the other hemodynamic variables in Group PA-1. The postural change in Group IVC did not exert a significant effect on the inferior vena caval pressure. Group PA-2 were initially placed in the flat prone position on a flat saddle frame, which produced no significant changes in the hemodynamic variables. Then the convex curvature of the frame was adjusted to the grade appropriate for surgery, which produced a significant reduction in CI (from 2.9 +/- 0.3 to 2.4 +/- 0.4, P less than 0.05). We conclude that the prone position itself may not interfere with the circulatory function. The prone position using a convex saddle frame causes significant reductions in CI, but little change in the other hemodynamic variables.

Ordering and Administration of Sedatives and Analgesics During Withholding and Withdrawal of Life Support from Critically 111 Patients

Abstract: OBJECTIVE To determine why and how sedatives and analgesics are ordered and administered during the withholding and withdrawal of life support from critically ill patients. DESIGN Prospective case series. SETTING Medical-surgical intensive care units at a county hospital and a university hospital. PATIENTS Consecutive 1-year sample of 22 patients from whom life support was withheld or withdrawn in one intensive care unit at a county hospital and a random sample of 22 similar patients in the intensive care unit in the university hospital over the same period. MAIN OUTCOME MEASURES Physicians and nurses were interviewed to determine their reasons for ordering and administering drugs, and medical records were reviewed to document amounts of drugs ordered and administered. RESULTS Drugs were given to 75% of patients during withholding and withdrawal of life support. Patients who did not receive medication were comatose and considered incapable of benefiting from sedation and analgesia. The median time until death following the initiation of the withholding or withdrawal of life support was 3.5 hours in the patients who received drugs and 1.3 hours in those patients who did not (P, not significant). Physicians ordered drugs to decrease pain in 88% of patients, to decrease anxiety in 85%, to decrease air hunger in 76%, to comfort families in 82%, and to hasten death in 39%; in no instance was hastening death the only reason cited. The amounts of benzodiazepines and opiates averaged 2.2 mg/h of diazepam and 3.3 mg/h of morphine sulfate in the 24 hours before withholding and withdrawal of life support and 9.8 mg/h and 11.2 mg/h in the 24 hours thereafter (P less than .025 and P less than .001, respectively). CONCLUSIONS Large doses of sedatives and analgesics were ordered primarily to relieve pain and suffering during the withholding and withdrawal of life support, and death was not hastened by drug administration.

Reduced Postoperative Hospitalization After Laparoscopic Cholecystectomy

Abstract: An initial experience of laparoscopic cholecystectomy in 50 consecutive patients was reviewed and the results compared with those of a group of 25 patients who underwent laparotomy cholecystectomy during the 3 months before the introduction of laparoscopic cholecystectomy. Laparoscopic cholecystectomy was successfully performed in 44 of 50 consecutive patients in whom it was attempted. When compared with laparotomy, laparoscopy cholecystectomy was associated with longer mean (s.d.) anaesthesia, 155 (61) min versus 102 (31) min (P less than 0.001), shorter mean postoperative hospital stay, 3.5 (1.5) versus 8.8 (3.2) days (P less than 0.001), and reduced mean cost, pounds 895 (376) versus pounds 2210 (822) (P less than 0.001). Perioperative morbidity was also reduced following laparoscopy cholecystectomy (9 per cent versus 16 per cent) but not significantly so. Laparoscopic cholecystectomy is a safe, effective procedure which completely removes the gallbladder. It significantly reduces hospital stay, is cosmetically satisfactory and has financial benefits. We suggest that this technique be considered for all patients having cholecystectomy.

Evaluation of the Routine Use of the Nasogastric Tube in Digestive Operations by a Prospective Controlled Study

Abstract: This prospective, randomized controlled trial was undertaken to evaluate the effect of tube decompression of the stomach after surgical procedure on the digestive tract. One hundred and nine patients were randomly allocated to postoperative treatment with (57 patients) or without (52 patients) nasogastric tubes. No significant differences were found between the two groups in the duration of hospitalization, time to begin peroral fluid intake, occurrence of hiccups, vomiting, nausea, parotiditis, nasal septum necrosis, anastomotic leak and wound dehiscence. Moreover, abdominal distension, pyrosis, otalgia, dysphagia, odynophagia and atelectasis occurred more often in intubated patients as shown by chi-square analysis of the data with Yates correction, with the level of significance at p = less than 0.05. Tube decompression of the stomach does not relieve intestinal paralysis after digestive operations. These data seem to indicate that the routine prophylactic use of a nasogastric tube is unnecessary in gastrointestinal operations.

Outcome of Noncardiac Operations in Patients with Severe Coronary Artery Disease Successfully Treated Preoperatively with Coronary Angioplasty

Abstract: The risk of perioperative myocardial infarction and death was evaluated in 50 patients (mean age, 68 years) with severe coronary artery disease who underwent a noncardiac operation after revascularization had been achieved by successful percutaneous transluminal coronary angioplasty. Before angioplasty, all patients were thought to be at high risk for perioperative complications on the basis of assessment of clinical variables and findings on specialized diagnostic tests. Of the 50 patients, 31 had Canadian Heart Association class III or IV angina or unstable angina. All patients who underwent functional testing had positive results. At catheterization, 38 patients (76%) had multivessel disease. The 50 patients underwent 54 noncardiac operations at a median of 9 days after angioplasty. The overall frequency of perioperative myocardial infarction was 5.6%, and the mortality was 1.9%. Two nonfatal non-Q-wave infarctions and one fatal Q-wave infarction occurred. In patients who have undergone successful angioplasty for severe coronary artery disease, the risk of major cardiac complications associated with a noncardiac surgical procedure is low.

Effectiveness of Preoxygenation in Morbidly Obese Patients

Abstract: The time taken for the oxygen saturation (SpoJ to decrease to 90%after preoxygenation was studied in six morbidly obese patients and six matched controls of normal weight. During apnoea the obese patients maintained Sp02*gt;90% for 196 (SD 80) s(range55–208 s), compared with 595 (so 142)s (range 430–825 s) in the control group (?

Operative Monitoring of Parathyroid Gland Hyperfunction

Abstract: With a 20-year experience of more than 700 parathyroidectomies, our persistent hypercalcemic postoperative failure rate of 7% has remained constant. Reasons for failure have been misdiagnosis or inability of the surgeon to detect and excise all hypersecreting glands. We have modified a commercially available immunoradiometric assay for intact parathyroid hormone (PTH) resulting in a 15-minute turnaround time. Since intact PTH has a half-life measured in minutes, whole blood samples taken 10 minutes after gland excisions were monitored intraoperatively to confirm significant changes in circulating hormone. Quantitative evidence that all hyperfunctioning parathyroid tissue had been ablated during operation was obtained in 19 of 21 patients. Less than four glands each were identified in 53% of these patients. The PTH “quick” test correctly pointed to an inadequate excision requiring further parathyroid ablation in two patients, made bilateral neck exploration unnecessary in two patients who had previously undergone parathyroidectomy, and predicted persistent hypercalcemia in two patients with complications.

Depression and the Chronic Pain Experience

Abstract: The present study examined the relationship between depression and a constellation of pain-related variables that describe the experience of chronic pain patients. Thirty-seven depressed and 32 non-depressed heterogeneous chronic pain patients were identified through structured interviews, use of standardized criteria and scores on the Beck Depression Inventory (BDI). The 2 groups were compared on demographic variables and scores on the Marlowe-Crowne Social Desirability scale (MC), as well as measures of disability and medication use, pain severity, interference due to pain and reported pain behaviors. The depressed group was found to be younger and to score lower on the MC than the non-depressed group. Multivariate analyses of covariance (MANCOVA), using age and MC as covariates, revealed that depressed chronic pain patients, relative to their non-depressed counterparts, reported greater pain intensity, greater interference due to pain and more pain behaviors. There were no group differences on the measures of disability and use of medications. The results provide further support for the importance of incorporating depression into clinical and theoretical formulations of chronic pain. Future use of structured interviews and standardized criteria for diagnosing depression may clarify some of the inconsistencies found in the literature.

Oropharyngeal Decontamination Decreases Incidence of Ventilator-Associated Pneumonia. A Randomized, Placebo-Controlled, Double-Blind Clinical Trial

Abstract: Secondary pneumonia in patients requiring mechanical ventilation has a high morbidity and mortality. Diagnosis is difficult and treatment failure common; therefore, preventive measures are important. In a double-blind, placebo-controlled trial, we evaluated selective decontamination of the oropharynx with polymyxin B sulfate, neomycin sulfate, and vancomycin hydrochloride (PNV) in 52 patients requiring mechanical ventilation during a 3- to 34-day period (mean, 10 days). Either PNV or placebo was administered six times daily in the oropharynx. During the first 12 days of intubation, tracheobronchial colonization by gram-negative bacteria and Staphylococcus aureus, as well as pneumonia, occurred less frequently in the PNV than in the placebo group (16% vs 78%; P less than .0001). Hospital mortality was not different, but systemic antibiotics were prescribed less often in the PNV group and no resistant microorganism emerged. In these critically ill patients, topical oropharyngeal antibiotic application lowered the rate of ventilator-associated pneumonia by a factor of 5, probably by interrupting the stomach-to-trachea route of infection, and decreased the requirement for intravenous antibiotics.