A new mask designed for patients implanted with a nasogastric tube

Pulmonary ventilation of patients implanted with a nasogastric tube is often difficult for medical personnel, since air leakage through the facemask and nasogastric tube interface is inevitable. Here we designed and tested a special facemask to improve ventilation in these patients. Forty patients with ASA class I-II were randomly assigned to two groups (study and control, n=20 each patients/group). All patients received abdominal surgery with a nasogastric tube inserted before operation. Before induction arterial lines were set up under local anesthesia. Blood gas samples were taken before, during and 1 min after endotracheal intubation. Haemodynamic data were obtained from the artery lines. Inspiratory and expiratory tidal volumes were measured by the Wright's spirometer connected to the anesthesia machine. For induction we used the new mask for the study group and the conventional mask for the controls. Blood gas values and leakage volumes were compared statistically (unpaired t-test, significant levels set at p<0.05). Air leakage was significantly reduced under the new mask with a concomitant improvement in PaO(2). There was however no change in terms of haemodynamic and PaCO(2) between the two groups. Results indicated the advantage of the new mask for patients with nasogastric tubes.