Effects of Transient Prone Position on Oxygenation and Oro-Nasal Drainage in Advanced Neuromuscular Diseases: Preliminary Study

Abstract

SESSION TITLE: Respiratory Care SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, November 1, 2017 at 01:30 PM - 02:30 PM PURPOSE: Although the effects of prone position in adult respiratory distress syndrome or acute lung injury have been investigated, those of transient prone position for 30 minutes on oxygenation and oro-nasal drainage in advanced neuromuscular diseases are mostly unknown. METHODS: Seven patients with preserved spontaneous breathing and nine patients fully dependent on positive pressure ventilation were studied, all of whom had a permanent tracheostomy due to suffocation or chronic alveolar hypoventilation prior to this study. According to the motor function criteria of the Japanese Administration of Health and Welfare, all the subjects were completely bedridden. Effects of posture were assessed with the breath-by-breath flow-metry and inspiratory/expiratory gas analysis (AE-3005, Minato Co. Japan) along with the arterial blood gas analysis. These respiratory variables were compared among the three conditions with a paired t-test: (1) supine position just before turning the subject prone (Pre-Control), (2) after 30 minutes in prone position (Prone), and (3) 30 minutes after resuming supine position (Post-Control). The differential effects of ventilation (spontaneous breathing/positive pressure ventilation) and posture (supine/prone) on these variables were analyzed with a repeated measures ANOVA, and a P<0.05 was considered statistically significant. RESULTS: The alveolar-arterial difference of partial pressure of oxygen (A-aDO2) was significantly decreased in prone position in the spontaneous breathing patients (Pre-Control vs Prone vs Post-Control: 24.3±11.8 vs 14.7±6.6 (P=0.04) vs 23.3±5.9 (P=0.004)). The PaO2 was significantly decreased in prone position in the ventilated patients (Pre-Control vs Prone: 95.5±12.8 vs 87.4±13.3) (P=0.03). Overall, the effects of ventilation (spontaneous breathing/positive pressure ventilation) and posture (supine/prone) on oxygenation were significantly different, (P=0.008 for PaO2) (P=0.008 for A-aDO2). The prone position improved oxygenation (an increase in PaO2 and a decrease in A-aDO2) in the spontaneously breathing patients and it worsened oxygenation (a decrease in PaO2 and an increase in A-aDO2) in the ventilated patients. In all cases, the transient prone position immediately augmented the gravitational drainage of salivary and nasal excretions for clearing the oro-nasal cavity. CONCLUSIONS: The transient prone position improved oxygenation in the spontaneously breathing patients and it worsened oxygenation in the ventilated patients, which might be attributed partly to that the drainage from the peripheral airway and alveoli could not be taken effects in 30 minutes in the ventilated patients with severe motor and respiratory dysfunction. The transient prone position could be useful for an immediate oro-nasal drainage for oro-nasal hygiene and, presumably, for respiratory care. CLINICAL IMPLICATIONS: The transient prone position might be utilized on an individual basis regarding oxygenation and oro-nasal drainage among patients with advanced neuromuscular diseases. DISCLOSURE: The following authors have nothing to disclose: Fumihiko Yasuma No Product/Research Disclosure Information