Wean From the Tube Not Necessarily From the Ventilator

Abstract

To the Editor: The recent article by Price and Rizk (May 1999 supplement),1Price J Rizk NW Postoperative ventilatory management.Chest. 1999; 115: 130S-137SAbstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar entitled “Postoperative Ventilatory Management,” discusses many aspects of postoperative ventilatory care but fails to consider all of the options for one uncommon, but not rare, situation. Patients with neuromuscular ventilatory impairment for whom postoperative ventilator weaning difficulty may be anticipated can be trained prior to surgery to use noninvasive intermittent positive-pressure ventilation (IPPV) and expiratory muscle aids.2Bach JR Update and perspectives on noninvasive respiratory muscle aids: Part 2. The expiratory muscle aids.Chest. 1994; 105: 1538-1544Abstract Full Text Full Text PDF PubMed Scopus (202) Google Scholar This training permits the option of extubating such patients even when they are unable to autonomously ventilate the lungs. We come across this situation most commonly in patients with vital capacities of < 30% of the predicted normal rate who require scoliosis reduction surgery. However, it can occur in anyone with advanced neuromuscular disease who requires surgery. Once trained in mouthpiece and nasal IPPV3Bach JR Update and perspectives on noninvasive respiratory muscle aids: Part 1. The inspiratory muscle aids.Chest. 1994; 105: 1230-1240Abstract Full Text Full Text PDF PubMed Scopus (88) Google Scholar and in manually and mechanically assisted coughing,2Bach JR Update and perspectives on noninvasive respiratory muscle aids: Part 2. The expiratory muscle aids.Chest. 1994; 105: 1538-1544Abstract Full Text Full Text PDF PubMed Scopus (202) Google Scholar the patients can usually be extubated when they meet the following criteria: 1.no requirement of supplemental oxygen to maintain arterial oxygen saturation at > 94%;2.cleared or clearing chest radiograph abnormalities;3.full alertness and discontinuation of any respiratory depressants;4.extubation to continuous noninvasive IPPV without supplemental oxygen; and5.ability to use oximetry feedback to guide the use of inspiratory and expiratory aids to augment cough flows and to reverse any desaturations due to airway mucus accumulation. Indeed, the “weaning” options are to wean from supplemental oxygen by clearing the airways and restoring normal pulmonary function, to remove any indwelling airway tubes whether the patient can breathe or not, and to let the patient wean from ventilator use by taking fewer and fewer assisted insufflations as needed to avoid dyspnea, oxyhemoglobin desaturation, and hypercapnia.3Bach JR Update and perspectives on noninvasive respiratory muscle aids: Part 1. The inspiratory muscle aids.Chest. 1994; 105: 1230-1240Abstract Full Text Full Text PDF PubMed Scopus (88) Google Scholar Since many patients who require continuous long-term ventilatory support do not have tracheostomy tubes, one cannot expect them to wean from ventilator use before postoperative extubation. Echocardiographic Predictors of an Adverse Response to a Nifedipine Trial in Primary Pulmonary Hypertension: Diminished Left Ventricular Size and Leftward Ventricular Septal BowingCHESTVol. 116Issue 5PreviewThe clinical course in primary pulmonary hypertension (PPH) is improved by calcium channel blocker therapy in those with a favorable hemodynamic response during a trial of high-dose oral nifedipine. Although trials of nifedipine are performed only in patients who demonstrate pulmonary vasodilator reserve to short-acting agents, this response does not predict the safety of nifedipine treatment, which can result in severe first-dose hypotension and death. Full-Text PDF