Introduction: Arterial hypoxaemia is not a rare complication of CABG. Incentive spirometry (IS) is a simple and low cost training method, which encourages an increase of lung volumes and inspiratory capacity. The purpose of the study was to investigate the efficiency of preoperative IS in CABG patients .
Method: The study included 65 randomly selected CABG patients 41 to 73 years of age. Patients were divided into 2 groups: patients of group S (37) used IS before surgery, group C (28 patients) were controls. IS was administered to group S patients for 2 days before surgery. Spirometry training was performed for 10 min each hour. Further, we started IS training at the second postoperative day. Anaesthesia and ventilation parameters were the same in both groups. Oxygenation index PaO2/FiO2, difference and Qs/Qt were observed at the following operation stages: before sternotomy (1), 10min after finishing CPB (2), at the end of operation (3), 3 and 6 hours after operation (4,5). Duration of MV was also observed. Statistical significance was calculated using Student's t-test.
Result: Are shown in the table:
Duration of CPB were 107 ± 6min and 106 ± 5min respectively. Haemodynamic parameters and left atrial pressure were the same in both groups during all observed time.
At the end of the second training day inspiratory capacity increased to 162% (P < 0.05). After operation inspiratory capacity was significantly lower and returned to baseline at the 6th postoperative day. No patients had severe myocardial failure after CPB (CI > 2.7l min−1 m−2). Arterial hypoxaemia with PaO2/FiO2 < 200 were observed in 13.9% group S and in 32% group C patients at stage 3 (P < 0.05). Duration of MV in group S was 7.3 h, in C 10.4h (P < 0.05). 32.5% of S and 13.3% of C group patients met the conventional criteria and were extubated in the OR (P < 0.05).
Discussion: Incentive spirometry significantly improved lung inspiratory capacity, arterial oxygenation and lung shunt after CPB. Spirometry training before and after operation is effective in decreasing the duration of MV.
1 Crowe JM, Bradley CA. The effectiveness of incentive spirometry with physical therapy for high-risk patients after coronary artery bypass surgery. Phys Ther