Development of a device to reduce gastro-esophageal reflux in critically ill patients

Summary Introduction Gastro-esophageal Reflux (GER) in mechanically ventilated patients is a contributing factor in the development of Ventilator-Associated Pneumonia (VAP). In this paper, we report pilot studies in an animal model and in human volunteers describing a new Peristaltic Feeding Tube (PFT) comprised of three balloons integrated into a nasogastric tube which are inflated and deflated in a co-ordinated sequential fashion to promote ante-grade passage of luminal contents through the esophagus into the stomach. Materials and methods In a series of studies involving an animal model (15 White Landrace pigs of 56–64 kg) and 3 human volunteers, the PFT was positioned under x-ray guidance, so that the distal balloon was located in the esophagus 3–4 cm proximal to the gastro-esophageal junction (GEJ), and then continuously operated for 8–72 h. The PFT was calibrated to ensure a maximum pressure exerted by the balloons on the internal esophageal wall of 30 mmHg. The anesthetized and mechanically ventilated pigs were maintained in the supine (8 h study) or the prone position (72 h study), while the human subjects were awake and maintained in the semi-recumbent position. Results In both an 8 h and a 72 h study, the pigs were stable throughout, with no evidence of hypotension or hypoxemia, drooling, inability to manage secretions or vomiting during the operation of the PFT. Macroscopic evaluation of the esophagus at the end of study did not reveal erythema, edema, erosions, ulcers or perforation of the esophageal wall. Histological sections obtained from the esophagus of each animal revealed no damage to the mucosal surface or at any depth of the esophageal wall, at either the control sites or at the sites where the PFT balloons had been active. All three volunteers were stable throughout the 8-h study period (BP, HR, ECG and SpO 2 ). None reported any pooling of saliva/secretions in the mouth or oro-pharynx or experienced vomiting. Pain/discomfort was reported in the range of 1–3.5 by subjects on a VAS scale from 0 (no pain) to 10 (worst pain ever). All three subjects reported on an awareness of the pulsation of the balloons in the esophagus. Upper GI endoscopy, before and after the 8-h trial period, failed to demonstrate any esophageal or gastric mucosal damage. Conclusions This PFT device is safe, and may provide an alternative strategy to prevent GER and perhaps reduce the risk of VAP.