危重病患者半仰、俯卧位机械通气的肠内喂养比较

 目的探讨俯卧位有创机械通气的危重患者进行早期肠内喂养的耐受情况.方法接受有创机械通气开始后24h内选择患者69例分成2组:半仰卧位组35例,俯卧位组34例.每天经14 F胃管注入,行肠内喂养18 h.当吸入氧浓度(FiO2)0.6、呼气末正压(PEEP) 10cmH2O,氧合指数(PaO2/FiO2)＜150时,即进行6 h俯卧位,同时头部轻度抬高.每6 h测量1次胃残留量,共5 d.结果俯卧位组与半仰卧位组患者比较基础氧合指数低(P＜0.01),与半仰卧位组相比俯卧位组患者胃残留量在第1、2、4天明显增高,并且俯卧位组比半仰卧位组更容易发生呕吐(P＜0.05).俯卧位组与半仰卧位组患者相比肠内喂养量明显偏低.俯卧位组俯卧位期间比半仰卧位期间呕吐发生率高(P＜0.01).结论俯卧位有创机械通气的危重患者难以耐受早期肠内喂养,半仰卧位对于俯卧位有创机械通气的危重患者可以增强胃排空和预防呕吐.

Enteral feeding of mechanically ventilated critically ill patients in prone position

Objective To assess the tolerance of early enteral feeding by critically ill patients receiving invasive mechanical ventilation in the prone position.Methods A total of 69 patients receiving invasive mechanical ventilation with early nasogastric enteral feeding were studied for 5 consecutive days while being treated continuously in semisupine position(semisupine group,n=35) or in intermittent prone position for severe hypoxemia(prone group,n=34).The patients were included within 24 hrs after initiation of mechanical ventilation.Daily 18-hr enteral feeding via a 14 F gastric tube was initiated.Prone patients were turned every 6 hrs as long as PaO_2/FiO_2 remained at <150,with a FiO_2 of 0.6 and positive end-expiratory pressure(PEEP) of l0 cmH_2O;the head was slightly elevated.When supine,patients in both groups were semirecumbent.Residual gastric volume was measured every 6 hrs,and enteral feeding was discontinued if it exceeded 150 mL or vomiting occurred.Results The baseline oxygenation index was lower in prone patients than in supine patients(P<(0.01)).Compared with supine patients,prone patients had significantly greater residual gastric volumes on days 1,2,and 4 and experienced more vomiting episodes(P<(0.05)).Enteral feeding was stopped in 79% of prone patients and 46% of supine patients(P<0.01) so that daily enteral feeding volumes were lower in prone position patients.In the prone group,vomiting occurred more frequently in the prone than in the supine position(P<(0.01)).Conclusions In critically ill patients receiving invasive mechanical ventilation in prone position,early enteral feeding is poorly tolerated.Gastrokinetic agents or transpyloric feeding and semirecumbency should be considered to enhance gastric emptying and to prevent vomiting in patients receiving mechanical ventilation in prone position.