Hypoxaemia and postoperative pulmonary complications

Abstract

UKCorrespondence to: Mr C. P. Aldren, Department of Otolaryngology, The Freeman Hospital, Newcastle upon Tyne NE7 7DN, UK After abdominal surgery patients are at risk of developing pulmonary complications which may result in oxygen de~aturationl-~. Current surgical practice is to rely on clinical assessment to detect such postoperative pulmonary complications. Any hypoxaemia suspected clinically is confirmed by arterial blood gas analysis.In this study the relationship between postoperative pulmonary complications detected by standardized clinical assessment and oxygen desaturation detected by pulse oximetry is examined in patients after laparotomy. Patients and methodsA prospective study was performed on 100 patients undergoing laparotomy who returned to a general surgical ward without requiring admission to an intensive therapy unit. The following factors were assessed before operation: previous medical history of respiratory or cardiac pathology, current respiratory symptoms or signs, smoking habits, emergency or routine surgery. The patients were examined twice daily for the first 5 days after operation (excluding the day of operation) and were considered to have a postoperative pulmonary complication if two or more of the following respiratory symptoms and signs were detected: cough, shortness of breath, pleuritic chest pain, temperature of more than 38"C, wheeze, crepitations, focal signs of infection or collapse, pleural rub.Oxygen saturations (Sao2) were measured twice daily by an independent observer who was unaware of the clinical findings, using a Kontron 7840 pulse oximeter (Kontron Instruments Ltd., Watford, UK). Such machines are in widespread clinical use and, although their accuracy is well d e~c r i b e d~-~, the observer was aware of the conditions leading to artifactual readings and suitable precautions were taken'.Patients were considered to have hypoxaemia if SaO2 was <90 per cent and to have severe hypoxaemia if SaO2 was < 85 per ~e n t~,~. Patients with postoperative pulmonary complications were treated with physiotherapy and antibiotics. Oxygen therapy was added if cyanosis or dyspnoea was present. ResultsThe mean age of the patients was 61 years with a male:female ratio of 48:52. Figures I , 2 and 3 show the incidence of pulmonary complications and hypoxaemia on each day after operation. Hypoxaemia and severe hypoxaemia occurred most frequently on day 1 and then decreased day by day. Only a minority of patients with clinically detectable postoperative pulmonary complications were hypoxaemic or severely hypoxaemic. A relatively poor correlation between hypoxaemia or severe hypoxaemia and clinically detectable pulmonary complications was noted for each postoperative day. Of the 30 patients who were hypoxaemic on day 1, 20 did not have postoperative pulmonary complications (Figure 3). Of these . 20 patients, six went on to develop pulmonary complications on a subsequent postoperative day. Hypoxaemia The relationship between severe hypoxaemia and postoperative pulmonary complications was als...

Postoperative study of vital capacity and ventilation measurements following elective craniotomy

“…[1][2][3][4][5][6][7] These changes include decreased lung volume ranging from 25% to 60%, 8 decreased tidal volume (TV), increased respiratory frequency, 9 gas exchange changes with decreased partial oxygen pressure 10,11 and decreased mucociliary clearance. 9 These changes occur more intensely in surgery involving the abdominal and thoracic cavity, and they contribute towards the development of pulmonary complications.…”