Antibiotic prophylaxis of respiratory tract infection in mechanically ventilated patients. A prospective, blinded, randomized trial of the effect of a novel regimen. Influence of combined intravenous and topical antibiotic prophylaxis on the incidence of infections, organ dysfunctions, and mortality in critically ill surgical patients: a prospective, stratified, randomized, double-blind, placebo-controlled clinical trial. Failure of topically applied antibiotics, added to systemic prophylaxis, to reduce perineal wound infection in abdominoperineal excision of the rectum. Prevention of colonization and respiratory infections in long-term ventilated patients by local antimicrobial prophylaxis. Prophylactic antibiotics in vascular surgery. Topical, systemic, or both? Prevention of ventilator-associated pneumonia by oral decontamination: a prospective, randomized, double-blind, placebo-controlled study. Antibiotics in elective colon surgery. A randomized trial of oral, systemic, and oral/systemic antibiotics for prophylaxis. Single-dose v. short-term antibiotic therapy for prevention of wound infection in general surgery. A prospective, randomized double-blind trial. Use of surfactant for prophylaxis versus rescue treatment of respiratory distress syndrome: experience from an Italian-Bulgarian trial.
The objective of this study was to assess the effect of a novel regimen of antibiotic prophylaxis on the incidence of lower respiratory tract infection in patients requiring prolonged (at least five days) mechanical ventilation. The design was a controlled, prospective, randomized trial, with blinded comparison of the groups regarding the incidence of respiratory tract infection in an intensive care unit of a university hospital. After determination of the APACHE II score for severity of disease, 88 patients were randomly divided in three groups. Twenty-four of these patients did not complete five days of mechanical ventilation, and eight were withdrawn for other reasons. Fifty-six patients (18 in group 1, 21 in group 2, 17 in group 3) completed the study. Patients in both control groups 1 and 2 did not receive antibiotic prophylaxis, but the two groups differed in the antibiotic policy in case of infection. Patients in group 3 received antibiotic prophylaxis consisting of norfloxacin, polymyxin E, and amphotericin B, applied topically in oropharynx and stomach from time of ICU admission until extubation, and intravenous cefotaxime 500 mg three times a day during the first five days of admission. In both control groups, about 90 percent of the patients acquired microbial colonization of oropharynx or stomach. In group 3, only 12 percent and 24 percent of the patients acquired colonization of oropharynx and stomach, respectively (p less than 0.001). This resulted in a reduction of the incidence of lower respiratory tract infection (78 percent in group 1, 62 percent in group 2, 6 percent in group 3 [p = 0.0001]). The regimen of antibiotic prophylaxis studied prevented respiratory tract infection in mechanically ventilated patients. Antibiotic prophylaxis should be considered in all patients expected to require prolonged mechanical ventilation. We prospectively studied the impact of an antibiotic prophylaxis regimen on the incidence of infections, organ dysfunctions, and mortality in a predominantly surgical and trauma intensive care unit (ICU) population. A total of 546 patients were enrolled and stratified according to Acute Physiology and Chronic Health Evaluation (APACHE)-II scores. They were then randomized to receive either 2 x 400 mg of intravenous ciprofloxacin for 4 days, together with a mixture of topical gentamicin and polymyxin applied to the nostrils, mouth, and stomach throughout their ICU stay or to receive intravenous and topical placebo. When receiving prophylaxis, significantly fewer patients acquired infections (p = 0.001, risk ratio [RR], 0.477; 95% confidence interval [CI], 0.367-0.620), especially pneumonias (6 versus 29, p = 0.007), other lower respiratory tract infections (39 versus 70, p = 0.007), bloodstream infections (14 versus 36, p = 0.007), or urinary tract infections (36 versus 60, p = 0.042). Also, significantly fewer patients acquired severe organ dysfunctions (63 versus 96 patients, p = 0.0051; RR, 0.636; 95% CI, 0.463-0.874), especially renal dysfunctions (17 versus 38; p = 0.018). Within 5 days after admission, 24 patients died in each group, whereas 28 patients receiving prophylaxis and 51 receiving placebo died in the ICU thereafter (p = 0.0589; RR, 0.640; 95% CI, 0.402-1.017). The overall ICU mortality was not statistically different (52 versus 75 fatalities), but the mortality was significantly reduced for 237 patients of the midrange stratum with APACHE-II scores of 20-29 on admission (20 versus 38 fatalities, p = 0.0147; RR, 0.508; 95% CI, 0.295-0.875); there was still a favorable trend after 1 year (51 versus 60 fatalities; p = 0.0844; RR, 0.720; 95% CI, 0.496-1.046). Surveillance cultures from tracheobronchial, oropharyngeal, and gastric secretions and from rectal swabs did not show any evidence for the selection of resistant microorganisms in the patients receiving prophylaxis. In a prospective, randomized trial, prophylactic use of topical antibiotics in addition to systemic prophylaxis was studied in patients undergoing abdominoperineal amputation of the rectum. All patients received gentamicin 80 mg and metronidazole 500 mg intravenously at induction of anesthesia, followed by the same dose 8 hourly for 48 hours. In accordance with the randomization, half of the patients were additionally given gentamicin 160 mg + metronidazole 400 mg topically into the perineal wound at closure. Perineal wound infection appeared in 19 of the 41 patients who received both systemic and topical prophylaxis, and in 18 of the 38 with only systemic antibiotics. Cell-mediated immunity was preoperatively assessed with a skin test (Multitest) in all but three patients. Impairment of cell-mediated immunity was associated with significantly heightened rate of wound infection, and these patients did not benefit from topical antibiotics. In a randomized clinical trial the prophylactic effects of locally administered antimicrobials on quantitative colonization and respiratory infections were studied in intubated patients with an expected period of mechanical ventilation of greater than 6 days. Nineteen patients received 50 mg of polymyxin B and 80 mg of gentamicin distributed among nose, oropharynx and stomach at 6-h intervals, as well as 300 mg of amphotericin B in the oropharynx. Twenty untreated patients served as controls. In the control group colonization by respiratory pathogens was more common (oropharynx 19 vs 6 patients (p less than 0.001); trachea 19 vs 11 (p less than 0.01)), and the number as well as the count of the colonizing species was usually higher. Fourteen patients of the control group developed respiratory infections, including nine cases of pneumonia, as compared to four patients with prophylaxis, including one case of pneumonia (p less than 0.01). Pneumonia-associated deaths were prevented with prophylaxis; however, the overall mortality remained unchanged. Respiratory infections in the prophylaxis group were associated with organisms resistant to the agents used, but the overall occurrence of resistance was not increased, as compared to the control group. We conclude that unrestrained upper airway colonization by respiratory pathogens and respiratory tract infection were causally related. Local antimicrobial prophylaxis proved to be a highly effective strategy for the prevention of potentially life-threatening pneumonias in critically ill patients, but in the present study the host setting appeared to be the major determinant of outcome. A prospective, randomized, blinded study was performed to determine whether prophylactic antibiotics would reduce the incidence of infection in peripheral vascular surgery and whether the route of antibiotic administration was important. Patients undergoing a vascular procedure with a groin incision were allocated to one of four groups with respect to prophylactic antibiotics. Group I received no antibiotic. Group II had topical cephradine instilled in their incisions prior to closure. Group III received a 24-hour perioperative course of intravenous cephradine, and Group IV received both topical and intravenous cephradine. Groin and abdominal incisional infections were significantly reduced (p < 0.01) among patients who received prophylactic antibiotics by either the topical, systemic, or combined routes of administration. No significant differences were noted among the three antibiotic groups. Profundoplasty, femoral embolectomy, and femoral aneurysm repair were each associated with an increased incidence of infection (p < 0.01). Other risk factors were only important in patients not receiving antibiotics. Either intraoperative topical antibiotics or perioperative systemic antibiotics prevent infection in peripheral vascular surgery, but antibiotic administration by both routes is unnecessary. Colonization of the intestinal tract has been assumed to be important in the pathogenesis of ventilator-associated pneumonia (VAP), but relative impacts of oropharyngeal, gastric, or intestinal colonization have not been elucidated. Our aim was to prevent VAP by modulation of oropharyngeal colonization, without influencing gastric and intestinal colonization and without systemic prophylaxis. In a prospective, randomized, placebo-controlled, double-blind study, 87 patients received topical antimicrobial prophylaxis (gentamicin/ colistin/vancomycin 2% in Orabase, every 6 h) in the oropharynx and 139 patients, divided over two control groups, received placebo (78 patients were studied in the presence of patients receiving topical prophylaxis [control group A] and 61 patients were studied in an intensive care unit where no topical prophylaxis was used [control group B]). Baseline characteristics were comparable in all three groups. Topical prophylaxis eradicated colonization present on admission in oropharynx (75% in study group versus 0% in control group A [p < 0.00001] and 9% in control group B patients [p < 0.00001]) and in trachea (52% versus 22% in A [p = 0.03] and 7% in B [p = 0.004]). Moreover, topical prophylaxis prevented acquired oropharyngeal colonization (10% versus 59% in A [p < 0.00001] and 63% in B [p < 0.00001]). Colonization rates in stomach and intestine were not affected. Incidences of VAP were 10% in study patients, 31% in Group A, and 23% in Group B patients (p = 0.001 and p = 0.04, respectively). This was not associated with shorter durations of ventilation or ICU stay or better survival. Oropharyngeal colonization is of paramount importance in the pathogenesis of VAP, and a targeted approach to prevent colonization at this site is a very effective method of infection prevention. Keywords: cross infection, prevention and control; respiration, artificial, adverse effects; antibiotics, administration and dosage infection control methods; pneumonia, etiology, prevention and control; intubation, intratracheal, adverse effects A prospective, randomized double-blind study was undertaken to compare the efficacy of three prophylactic regimens (oral neomycin and erythromycin, intravenous cefoxitin, and a combination of both oral and intravenous antibiotics) in patients undergoing elective colorectal surgery. One hundred sixty-nine patients were randomized and 146 patients were evaluable. Septic complications occurred in 11.4 per cent of patients receiving oral antibiotics only, in 11.7 per cent of patients receiving intravenous cefoxitin alone, and in 7.8 per cent of patients receiving both oral and intravenous antibiotics. These differences were not statistically different. The greatest number of septic complications occurred in those patients with anastomotic disruptions. Two patients died (1.3%), both of whom had major anastomotic failures. There was no advantage between any of the groups in the incidence of wound infection (3.9-6.8%). Thus, no advantage could be identified in this study in the combination of oral and intravenous antibiotics in elective colorectal surgery. To investigate the effectiveness of a single-dose antibiotic regimen for preventing postoperative wound infection, a prospective, randomized double-blind trial was carried out in patients undergoing "clean-contaminated", "contaminated" or "clean" (vascular) surgery. Both elective and emergency operations were included. Single-dose (preoperative) prophylaxis was compared with short-term prophylaxis (1 dose preoperatively and 2 doses postoperatively). The antibiotics were penicillin, tobramycin and metronidazole in various combinations, and comparisons between single-dose and short-term prophylaxis were made with all the regimens. The incidence of wound infection was 5/277 (1.8%) in the short-term group and 9/287 (3.1%) in the single-dose group. The difference was not statistically significant. Nor was statistically significant difference found when the type of operation and the degree of contamination were considered. Single-dose antibiotic prophylaxis thus gave a low incidence of postoperative wound infection, even in "clean-contaminated" or "contaminated" cases. To show if surfactant applied in different social-sanitary realities as prophylaxis of respiratory distress syndrome (RDS) is equally useful and able to reduce mortality and incidence of 3-4 radiological grade RDS.
                Two neonatal intensive care units (NICU) in Italy, one NICU in Bulgaria and one NICU in Romania were involved in a randomized controlled clinical trial of prophylaxis vs rescue treatment of RDS. Babies with gestational age 26-30 wks were randomized before birth to prophylaxis in the delivery-room with 200 mg/kg of porcine surfactant (prophylaxis) or to routine assistance (control). Subsequently the babies developing RDS requiring mechanical ventilation and fraction of inspired oxygen (FiO2) > or = 0.4 to maintain PaO2 about 50 mmHg were allowed to be treated rescue with 200 mg/kg of the same surfactant. To reach end-points of reducing mortality by 40% and incidence of radiological grade 3-4 RDS a total number of 174 patients were required.
                Due to logistic, practical and social-political problems the study was interrupted after enrollment of 93 babies (61 in Italy and 32 in Bulgaria). The Romanian centre did not start the study because it was impossible in the scheduled times to equip it for mechanical ventilation of the newborn infants. Analysis done on an intention to treat basis did not show significant reductions of mortality and 3-4 radiological grade RDS, even if there was a trend towards a reduction in the babies given prophylaxis. A significantly lower number of babies given prophylaxis required a subsequent rescue treatment compared to controls (p < 0.001). There was no difference in other complications such as intraventricular haemorrhage, air-leak syndromes and infections between prophylaxis and control infants. As regards pulmonary gas exchange, the PaO2/FiO2 ratio was significantly improved in the babies given prophylaxis for the first 12 hours of life vs the controls.
                Even if the study was terminated before term, the analysis of the data shows that prophylaxis with surfactant is equally effective in different social-clinical conditions to improve pulmonary gas-exchange, especially in the first critical hours of life of premature babies.
A combination of topical and systemic prophylactic antibiotics reduces RTIs and overall mortality in adult patients receiving intensive care. Treatment based on the use of topical prophylaxis alone reduces respiratory infections but not mortality. The risk of resistance occurring as a negative consequence of antibiotic use was appropriately explored only in one trial which did not show any such effect.