Non-invasive ventilation corrects alveolar hypoventilation during spinal anesthesia

Abstract

Purpose: To document and explain the beneficial effects of non-invasive ventilation in correcting hypoxemia and hypoventilation in severe chronic obstructive pulmonary disease, during spinal anesthesia in the lithotomy position. Clinical features:A morbidly obese patient with severe chronic obstructive pulmonary disease underwent prostate surgery in the lithotomy position under spinal anesthesia. Hypoxemia was encountered during surgery, and a profound decrease of forced vital capacity associated with alveolar hypoventilation and ventilation/perfusion mismatching were observed. In the operating room, an M-mode sonographic study of the right diaphragm was performed, which confirmed that after spinal anesthesia and assuming the lithotomy position, there was a large decrease (-30%) in diaphragmatic excursion. Hypoxemia and alveolar hypoventilation were successfully treated with non-invasive positive pressure ventilation. Conclusions:Intraoperative application of non-invasive positive pressure ventilation improved diaphragmatic excursion and overall respiratory function, and reduced clinical discomfort in this patient. A N obese patient suffering from severe chronic obstructive pulmonary disease (COPD) utilizing his "hypoxic drive", underwent surgery in the lithotomy position (LP) under spinal anesthesia (SA). The respiratory consequences of both the anesthetic technique and patient positioning were studied. Impending hypoxemic respiratory failure, potentially requiring endotracheal intubation and controlled ventilation, was successfully treated with non-invasive positive-pressure ventilation (NiPPV). In accordance with the Institutional Review Board, all details of this procedure were discussed with the patient, and his written informed consent was obtained for the procedure and the publication of his personal health information. Objectif Case reportA 58-yr-old obese man (105 kg, body mass index 34 kg·m -2 ) with severe COPD was scheduled for transurethral resection of the prostate under SA. He was a heavy smoker with a 40-pack-yr history of cigarette usage and consequent severe respiratory disability. During four previous surgeries, supplemental oxygen administration had produced a hypoventilatory

Noninvasive ventilation during spontaneous breathing anesthesia: an observational study using electrical impedance tomography

“…Indeed, in PSV, the tidal volume achieved depends on the patient's own effort added to that of the ventilator's inspiratory pressure. In this mode, an improvement in diaphragmatic ventilator excursion has been reported by ultrasonography [14]. We observed that the dependent lung in lateral decubitus position received significantly more ventilation than the nondependent lung in awake patients during SB.…”

“…PSV is a ventilator mode recently available in anesthesia ventilators. Use of NIV in anesthesia has been reported during the preoxygenation phase in obese patients to enhance oxygenation before intubation [8,9] and also in the intraoperative period in 3 settings [10]: therapeutic to treat an established perioperative acute respiratory failure, prophylactic in patients with chronic severe respiratory limitations, and prophylactic in sedated healthy patients to avoid hypoventilation due to anesthesia [11][12][13][14][15][16][17][18]. Effects of spontaneous breathing during general anesthesia were assessed by comparing the ventilation distribution in 30 nonobese patients enrolled in a randomized trial [19].…”

Awake palliative thoracic surgery in a high‐risk patient: one‐lung, non‐invasive ventilation combined with epidural blockade

“…Our experience combined with evidence from published case reports of the combination of non-invasive lung ventilation and regional anaesthesia techniques [8][9][10][11][12] suggests that even critically ill patients may successfully undergo major abdominal and thoracic surgery in this manner. In this case we used BiPAP, since the increased inspiratory pressure aids lung inflation while the positive expiratory pressure prevents alveolar collapse [1].…”

“…However, in critically ill patients, some elements of VATS procedures are likely to increase the chances of acute ventilatory failure. These include the lateral position, the iatrogenic pneumothorax and the duration of the operation, often in excess of 1 h. Non-invasive methods of mechanical lung ventilation may minimise the incidence of respiratory complications while allowing effective lung ventilation [7], and these methods have been used to assist spontaneous lung ventilation during abdominal surgery [8][9][10][11][12]. We describe the use of non-invasive ventilation during thoracic surgery.…”

Unusual applications of noninvasive ventilation

“…Although these patients pose substantial challenges to the anaesthetist, based on this preliminary experience, we think that critically ill patients scheduled for palliative surgery can be successfully managed with the combination of minimally invasive surgical techniques, neuraxial block and NIV. Our unpublished experience combined with evidence from published case reports of the combination of NIV and regional anaesthesia techniques [67][68][69][70][71] suggests that even critically ill patients may successfully undergo major abdominal and thoracic surgery in this manner.…”