The efficacy of a novel peristaltic feeding tube (PFT) in reducing reflux and aspiration of gastric contents in mechanically ventilated patients.

This study is a prospective, single-center, randomized, open label, controlled clinical study to determine the safety and initial efficacy of the PFT device for the reduction of GER in mechanically ventilated patients in the cardiothoracic intensive care unit (ICU). Institutional ethics approval was obtained (RMC-0378-15). Subjects who meet the study’s entry criteria and have none of the exclusion criteria and who give written informed consent are entered into the trial. This preliminary study will include 10 patients in the treatment group (with PFT) and 10 patients in the control group (with standard nasogastric tube). All subjects are patients who had undergone elective cardiac surgical procedures and who are mechanically ventilated in the ICU afterwards. This allows for a fairly homogenous study population, with no significant lung disease prior to study enrolment. Furthermore, as the procedures are elective, the subjects are able to give consent pre-operatively and so avoid the difficulty of obtaining consent from sedated and ventilated patients. The study will be performed for a total duration of approximately 12 hours in each patient. A randomization list was generated using a computerized algorithm. The randomized sequences were sealed in envelopes prior to study initiation. All subjects undergo a standard physical examination prior to enrolment to diagnose and document any significant abnormalities or diseases. Patients' demographic and medical information acquired from the subject or their medical chart including age, gender, previous medical history, and prior relevant medical information (such as existence of GERD) are recorded in the study case report form (CRF). Physical examination, laboratory and imaging findings are also recorded in the CRF. Standard peri-operative blood tests are carried out, with no need for study-specific blood tests. Serum or urine Human Chorionic Gonadotropin (HCG) are assayed in female patients of child-bearing age to rule-out pregnancy. All patients are nursed in the semi-recumbent position in the ICU with the head of the bed elevated to 30 degrees above horizontal for the entire duration of the study, unless a medical need arose for a position change. In the treatment group the LunGuard PFT is placed in subjects on admission to the ICU by a doctor and correct positioning is verified by X-ray, as described below. The control group has a standard polyurethane nasogastric tube (NGT) inserted as is standard practice for all patients who are mechanically ventilated. Enteral nutritional formula is provided as per unit protocol in both groups, via the central lumen of the PFT or via the standard NGT. All patients, both the control and treatment groups, are intubated with endotracheal tubes (ETT) that allow suctioning above the ETT cuff (Taperguard Evac tube, Covidien, Colorado). Study specimens are collected for Pepsin assay by suctioning at the following sites during the period that patients were mechanically ventilated: From the oropharynx, every hour, From above the tracheal tube balloon, every hour and From the trachea, every four hours. All of these suction samples are then analyzed for the presence of Pepsin A, which as it originates only from the stomach, is a valid marker for secretions of gastric origin. The concentration of Pepsin A is measured using an ELISA immunoassay (Wuhan EIAab Science Co., Ltd, East Lake Hi-Tech Development Zone, Wuhan China). Placement and management of the PFT – The PFT is connected to the control management unit (CMU) and a self-test is performed. The results of this test are recorded by the control system and also in the CRF. If the self-test failed, the PFT is replaced. If malfunction continued, the CMU is replaced. The PFT is placed in treatment subjects on admission to the ICU as we have previously described. In summary, prior to insertion, the physician estimates the distance from the subject's teeth in the midline anteriorly and the gastro-esophageal (GE) junction. The PFT is well lubricated with a water soluble lubricant before insertion. The distal balloon is positioned in the stomach and inflated by the CMU . The tube is then gently pulled back until a significant rise occurs in the internal pressure of the distal balloon as monitored by the CMU (due to the fact that the esophagus/GE junction is of smaller diameter than the stomach). The distal balloon is then deflated and pulled back another 6-7 cm. The goal is to position the distal balloon three to four (3-4) cm above the GE junction). X-ray imaging (the routine post-operative chest x-ray) is then performed to measure the actual location of the distal balloon in relation to the GE. The PFT and its balloons include radiopaque markers that can be detected via X-ray. The PFT is removed upon completion of the study. As a safety precaution, the device's maximum allowed pressure is not allowed to exceed 25 mmHg under any circumstances via a pressure limiter in the CMU's processor. Adverse events are recorded during the study if they occur. Esophageal pressure monitoring, which is an intrinsic ability of the PFT device, is noted throughout the study for future integration in mechanical ventilation strategies, as a surrogate measure of pleural pressure, but is not reported as part of this study. Follow up is performed at 10 days post treatment. The follow up consists of recording any changes in the patient's clinical condition, and any complications, including VAP. VAP is assessed according to the current CDC Guidelines for VAP events. In the event that the patient is released prior to 10 days post treatment, a phone call follow up visit is performed at the 10th day post treatment in order to inquire regarding the patient's general condition, pain possibly related to the device and in particular any evidence of VAP (fever, cough, respiratory secretions, shortness of breath). Statistics – Demographic data and Pepsin concentrations for the treatment and control group are compared using T-test analysis. The number of positive Pepsin samples at each site sampled are compared using Chi-Squared Wald testing.