Sirvent 1994.

Methods	Randomised controlled trial
Participants	Baseline characteristics Number randomised: 51 participants Number analysed: 51 participants Antacids + ranitidine Age (years; mean (SD)): 42.6 (18.2) Number of participants (n): 25 Gender (male/female; n): 16/9 Sucralfate Age (years; mean (SD)): 38.1 (19.7) Number of participants (n): 26 Gender (male/female; n): 20/6 Inclusion criteria Admitted at ICU of Hospital de Bellvitge Princeps d’Espanya On mechanical ventilation Predicted intubation time of more than 72 hours Exclusion criteria Reasonable suspicion of airway infection at the time of admission History of active gastro duodenal ulcers in the last six months Gastrointestinal bleeding at the time of admission Surgery of the digestive tract (laparotomies, gastrectomies, pancreatitis and neoplasias) Paralytic ileus Diffuse or localised peritoneal infection Receiving prophylactic treatment with antacids, H2 blockers, sucralfate within 24 hours before admittance to the ICU Baseline imbalances: Groups were similar in demographic characteristics. Antacid + Ranitidine group had an APACHE II score of 14.7 ± 4.9, and sucralfate group had a score of 13.2 ± 5.1 More participants in the sucralfate group were diagnosed with polytrauma (n = 16 vs 4 in the sucralfate group)
Interventions	Antacids + ranitidine Dose (total/d): antacid varies, 100 mg ranitidine Duration of treatment (days): until extubation or when pneumonia was diagnosed Route: NG tube IV Intervention: antacids via nasogastric tube to maintain gastric pH superior to 4 every 4 to 6 hours and ranitidine intravenous 50 mg/12 h Concomitant medications: 12 participants received parenteral nutrition; antibiotics; and glucocorticoids Sucralfate Dose (total/d): 4 g Duration of treatment (days): until extubation or when pneumonia was diagnosed Route: NG tube Intervention: sucralfate, nasogastric tube, 1 g every 6 hours Concomitant medications: 11 participants received parenteral nutrition; antibiotics; and glucocorticoids Adherence to regimen: no change in dose/regimen mentioned. No information about dropouts Duration of trial: January 1990 to June 1991 Duration of follow‐up: ‐
Outcomes	Outcomes sought in review and reported in trial Primary outcomes Incidence of nosocomial pneumonia Secondary outcomes Incidence of upper GI bleeding All‐cause mortality in ICU (not separately mentioned for each group) Adverse events of interventions (nil) Outcomes sought but not reported in trial All‐cause mortality in hospital Duration of intubation Duration of ICU stay Participants requiring blood transfusion Units of blood transfused Outcomes reported but not used in review Etiology of nosocomial pneumonia Time to outbreak of nosocomial pneumonia Differential effect on gastric pH Gastric colonisation
Notes	Setting: Hospital de Bellvitge‐Princeps d’Espanya Source of funding: grant from the heath ministry Conflicts of interest: ‐ Ethics approval: Study was approved by the clinical investigations committee at the Hospital Informed consent: ‐ Clinical trials registration: ‐ Sample size calculation: ‐ Additional notes: Two episodes of mild upper GI bleeding occurred in each group; this was not of clinical significance
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: not clearly mentioned in the study report
Allocation concealment (selection bias)	Unclear risk	Comment: not clearly mentioned in the study report
Blinding of participants and personnel (performance bias) All outcomes	High risk	Comment: This was not a placebo‐controlled trial, and the different modes of administering study interventions would not have made it possible to blind study personnel and participants
Blinding (detection bias) Clinically important upper GI bleeding	Unclear risk	Comment: Study did not address this outcome
Blinding (detection bias) Nosocomial pneumonia	Low risk	Comment: Study mentions that 2 outcome assessors were blinded
Blinding of outcome assessment (detection bias) Adverse reactions of interventions	Low risk	Comment: unclear on blinding of assessors for other outcomes. However owing to the objective nature of the outcomes of interest, the likelihood of detection bias is low
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: All randomised participants were part of the final analysis
Selective reporting (reporting bias)	High risk	Comment: All‐cause mortality in the ICU was not separately mentioned for each group. However, all other intended outcomes were analysed and reported
Other bias	Low risk	Comment: This study was funded by the ministry of health. The role of the sponsor in the conduct and reporting of the trial is unclear. No other sources of bias suspected