The Mechanism of Hypoxaemia After Laparotomy

The effect of three postoperative regimens of respiratory therapy on pulmonary complications and lung function was compared in high-risk patients. Fifty-one patients were randomized to: 1) conventional chest physiotherapy alone (PHYS), 2) chest physiotherapy and positive expiratory pressure (PEP), or 3) chest physiotherapy with both positive expiratory pressure and inspiratory resistance (RMT). Treatments were given twice daily by a physiotherapist and self-administered. The incidence of postoperative pulmonary complications (PPC) was respectively, 71%, 76% and 65% in the PHYS-, PEP- and RMT-groups. The incidence of PPC requiring treatment with antibiotic, bronchodilator or supplementary oxygen according to the existing clinical practice was 47%, 47% and 29%. The incidence of atelectasis was 65%, 64% and 60% and of pneumonia 29%, 35% and 6%. There was no difference between the groups, except for a tendency to a lower frequency of pneumonia in the RMT-group. Postoperatively forced vital capacity (FVC) decreased to mean 54%, forced expired volume in 1 s to 48% and functional residual capacity to 76% of preoperative values. Arterial oxygen tension (PaO2) declined to mean 8.1 kPa and arterial saturation (SaO2) to 89%. There was no difference between the groups except for FVC, PaO2 and SaO2 (P = 0.008, P = 0.008 and P = 0.002), which showed the least decrease in the RMT-group. None of the regimens could be considered as satisfactory concerning the prevention of PPC, but RMT seemed to be the most efficient. Insufficient self-administration of treatment was probably one of the causes of the overall high incidence of PPC in this study.

Section: Patients Treated F O R P P C Antibiotics Bronc Hodilators Sumentioning

confidence: 99%

Postoperative pulmonary complications and lung function in high‐risk patients: a comparison of three physiotherapy regimens after upper abdominal surgery in general anesthesia

Christensen

Schultz

Jensen

et al. 1991

“…As mentioned above, arterial oxygen tension is lowered after general anaesthesia, especially in elderly patients who are given postoperative opiate analgesia on demand (NUNN 1962, GEORG et al 1967, BAY et al 1968, RENCK 1969, SJOGREN &WRIGHT 1972, WIKLUND 1975, MODIG 1976. Contrary to what was previously believed, it has been found that this is usually not due to decreased alveolar ventilation.…”

Section: Arterial Oxygen Tensionmentioning

confidence: 99%

Regional Blockade Versus Analgesic Therapy

Wiklund¹

1982

Like other investigators, we have found that the postoperative period is characterized by high energy expenditure, pain, high plasma catecholamines and decreased arterial oxygen tension, and also glyrogenolysis, lipolysis, proteolysis and a low turn-over rate of glucose. Regional anaesthesia has often been supposed to counteract some of these phenomena without causing ventilatory depression. During the past few years a number of studies have been carried out in our department with the aim of elucidating possible diflerences between the effects ofsystemic analgesics and different regional anaesthetic blockades. Thus, we have found that both systemic analgesics and regional anaesthesia decrease the total postoperative energy expenditure. Adequately administered regional anaesthesia and systemic analgesic therapy both relieve postoperative pain, the former without interfering with normal ventilatory function. In addition, regional anaesthetic techniques cause less mental confusion, fewer bowel problems and possibly less postoperative lung complications. Moreover, high spinal blockades seem to be the only means of reducing the post-traumatir metabolir stress reaction.

“…In the control group, PaCO, was 41.4 mm Hg (S.D. 3.3) before anaesthesia and 41.9 mm Hg (S.D. 4.2) after anaesthesia.…”

Section: Resultsmentioning

confidence: 89%

Carbon Dioxide Administration for Correction of Postoperative Hypoxaemia

Hald

Johansen

1970

In most patients, anaesthesia and surgery are followed by a normocapnic decrease in PaO, (GORDH (1958) 4, NU" and PAYNE (1 964)11, BENDIXEN et a]. (1965( )l, GEORG et al. (19673) which can be attributed to one or more of the following factors : ventilation-perfusion disturbances, increased venous admixture, and decrease in cardiac output (SELLERY (1968y).It has been suggested that active pulmonary physiotherapy in the anaesthesia recovery phase could modify this reaction (HAMILTON et al. (1964)O).Since carbon dioxide will also exert its respiratory stimulating action in the presence of anaesthetics (SEVERINGSHAUS ( 1965)14) and during partial neuromuscular blockade (JQRGENSEN and JOHANSEN (1965)#), the effect of increased carbon dioxide concentration in the inspired air on postoperative oxygenation was investigated in the present study. METHODThe ventilatory state of the patients was evaluated from measurement of PaO,, PaCO, and pH with the appropriate Radiometer electrodes, calibrated with water at 38°C. 30 litres per minute of humidified atmospheric air containing 2 per cent carbon dioxide were administered for 20 minutes through one nostril (from 20 to 41) minutes postoperatively). The ventilatory response to CO, was measured on a Tissot spirometer after collection of expired air in a nonrebreathing system; the inspired air was in t h e instances delivered into a modified Ayres T-piece arrangement, and the nostrils were occluded. Arterial blood samples were drawn pre-operatively, 20 minutes after operation, 40 minutes after, i.e. before discontinuance of the GO, inhalation, and in some patients also 60 minutes postoperatively and on the following day.