Antacid versus cimetidine in preventing acute gastrointestinal bleeding. A randomized trial in 75 critically ill patients.

Over a 15-month period, 75 critically ill patients at risk of acute gastrointestinal bleeding were randomized into two groups: one group (38 patients) received the H2-blocker cimetidine intravenously at an initial dosage of 300 mg every six hours, and the other group (37 patients) received antacid (Mylanta II) through a nasogastric tube at an intial dosage of 30 ml every hour. Gastric pH was measured hourly and titrated above 3.5. Upper-gastrointestinal-tract bleeding occurred in seven of 38 cimetidine-treated patients but in none of 37 antacid-treated patients (P less than 0.01). When antacid titration was added to the cimetidine regimen in four of seven patients with bleeding, all four stopped bleeding. Renal failure, sepsis, peritonitis, hypotension, respiratory failure, jaundice, multiple trauma, and major operative procedures were associated with an increased incidence of bleeding. Cimetidine does not adequately protect seriously ill patients from acute upper-gastrointestinal-tract bleeding. Antacid is better for this purpose.

Antacid titration in the prevention of acute gastrointestinal bleeding: a controlled, randomized trial in 100 critically ill patients.

We randomized 100 critically ill patients at risk of developing acute gastrointestinal ulceration and bleeding into two groups. One (51 patients) received antacid prophylaxis, and the other (49 patients) received no specific form of prophylaxis. Hourly antacid titration kept the pH of the gastric contents above 3.5. Two of the 51 patients who received antacid prophylaxis and gastrointestinal bleeding. Twelve of the 49 control patients bled (P less than 0.005). Of the 12 patients in the control group who bled, seven were placed on antacid medication, and all seven apparently stopped bleeding. Analysis of all the patients showed that an increasing prevalence of respiratory, failure, sepsis, peritonitis, jaundice, renal failure and hypotension was correlated with a greater frequency of bleeding. No patients required operative treatment to control bleeding. These data indicate that the occurrence of acute gastrointestinal bleeding in critically ill patients can be reduced by antacid titration.

Aerosol polymyxin and pneumonia in seriously ill patients.

Pneumonia caused by Pseudomonas aeruginosa occurs frequently in critically ill patients and is associated with a mortality rate of 70 per cent. An aerosol of polymyxin B was administered (2.5 mg per kilogram per day) to the upper airways of 292 patients in a respiratory-surgical intensive-care unit during a seven-month period, in an attempt to prevent Ps. aeruginosa pneumonia. Although only one of the patients studied acquired pneumonia due to Ps. aeruginosa, 10 others acquired pneumonia caused by a polymysinx-resistant organism. Seven pneumonias were caused by organisms not frequently pathogenic to man (flavobacteria, serratia and Streptococcus faecalis). The mortality rate for acquired pneumonia in this study, 64 per cent, is greater than that in previous studies in which either no polymyxin or cyclic polymyxin therapy was used. Continuous use of polymyxin B aerosol appears to be a dangerous form of therapy.

Prevention of gram-negative bacillary pneumonia using polymyxin aerosol as prophylaxis. II. Effect on the incidence of pneumonia in seriously ill patients.

All 744 patients admitted to a Respiratory-Surgical Intensive Care Unit (RSICU) were included in a prospective study of the effects of a polymyxin (2.5 mg/kg body wt/day in six divided doses) or a placebo aerosol sprayed into the posterior pharynx and tracheal tube (if present), during 11 alternating 2-mo treatment cycles. The incidence of upper airway colonization in the RSICU with Pseudomonas aeruginosa was 1.6% during the polymyxin treatment cycles (total 374 patients) and 9.7% during the placebo cycles (370 patients) (X2 equals 23.2, P less than 0.01). 3 patients in the RSICU acquired Pseudomonas pneumonia, as defined by independent "blinded" assessors, during the polymyxin cycles while 17 acquired a Pseudomonas pneumonia during the placebo cycles (X2 equals 10.2, P less than 0.01). The overall mortality was similar in both placebo and polymyxin-treated groups (12.2 vs. 12.0%). Systemic antibiotic usage was similar in the different cycles; 49% of patients in the placebo and 53% in the polymyxin-treated groups received systemic antibiotics while in the RSICU.

Prevention of gram-negative bacillary pneumonia using aerosol polymyxin as prophylaxis. I. Effect on the colonization pattern of the upper respiratory tract of seriously ill patients.

A prospective study used polymyxin B by aerosol to reduce colonization of the upper respiratory tract with nosocomial gram-negative bacilli. 58 high-risk patients from the Respiratory-Surgical Intensive Care Unit entered the trial. 33 were randomly selected to receive 2.5 mg/kg/day of polymyxin B by hand atomizer into the pharynx, and tracheal tube if present. 17 of 25 control patients became colonized with gram-negative bacilli as compared with 7 of 33 polymyxin-treated patients (p < 0.01). Control patients became colonized with a total of 33 gram-negative bacilli: 3 were Pseudomonas aeruginosa, 21 were species of Enterobacteriaceae. The polymyxin-treated patients became colonized with a total of 11 gram-negative bacilli: no P. aeruginosa and only 3 species of Enterobacteriaceae were recovered. Colonization increased with duration in Respiratory-Surgical Intensive Care Unit and with time of required controlled ventilation. Polymyxin most effectively prevented the increase in colonization in treated patients who stayed in the Respiratory-Surgical Intensive Care Unit for longer than 1 wk and who required controlled ventilation for at least 72 h.