The mortality in the patients randomised to the supine position was 11/112 (9.8%) compared with 17/117 (14.5%) in those randomised to the semi-recumbent position

(OR 0.64, 95% CI 0.27–1.53, p = 0.277). Other outcome variables were similar in each group. Independent risk factors associated with a fatal outcome by multivariate analysis were an older age (p < 0.001), current or previous injecting drug abuse (p < 0.001) and the occurrence of autonomic instability (p < 0.001). In the 36 patients with a TSS ≥8, the mortality was 19 (52.8%) compared with 9 (4.7%) in the 193 patients with a TSS < 8 (OR 22.9, 95% CI 8.2–65.4, p < 0.001). In this study a semi-recumbent (30°) or supine nursing position for patients with severe tetanus had no effect on the frequency and rate of HCAP. This result contrasts with two previous

studies in general ICU see more patients. A multivariate analysis of 277 patients requiring mechanical ventilation found that a supine head position during the first 24 h of mechanical GSI-IX ventilation was independently associated with ventilator-associated pneumonia (VAP) and mortality.14 A randomised controlled trial in which ventilated patients on a general ICU were randomised to nursing in a semi-recumbent (45°) versus a supine position reduced the frequency of HCAP from 34% to 8% (p = 0.003) and microbiologically confirmed pneumonia from 23% to 5% (p = 0.018).15 This study, which was stopped before the planned sample size had been reached, showed that supine body position, enteral nutrition, mechanical ventilation for 7 days or more and a Glasgow Coma Score of less than 9 were independent risk factors for HCAP. A subsequent randomised trial comparing nursing ventilated patients at a 45° semi-recumbent position versus 10° in the control group failed to prevent the development of VAP.16 In that study, in which bed elevation was monitored by a transducer with pendulum, it was

observed that it proved impossible to maintain the targeted backrest elevation of 45° for semi-recumbent positioning and the mean achieved treatment position was 28°. Liothyronine Sodium The oropharynx of patients who have a tracheostomy or who are mechanically ventilated, rapidly become colonised with an abnormal bacterial flora, particularly Gram-negative bacteria. Reflux of colonised gastric contents into the oropharynx probably contributes to this process. Subsequent aspiration of these organisms into the respiratory tract is suggested to be part of the pathogenic process leading to HCAP. Studies with radioactively labelled gastric contents indicate that positioning ventilated patients in a semi-recumbent position reduces reflux into the oropharynx and subsequent aspiration into the lung.17 and 18 This is the rationale for nursing patients in the semi-recumbent position.