Chest Physiotherapy for Preventing Postoperative Pulmonary Complications
Special Feature
Chest Physiotherapy for Preventing Postoperative Pulmonary Complications
By Jun Takezawa, MD
Although the definition of postoperative pul-monary complications differs among authors in the literature, somewhere between 4.5% and 80% of patients undergoing upper abdominal surgery develop pulmonary problems. The risk factors for postoperative pulmonary complications were thought to be inadequate pain relief, a decrease in functional residual capacity with resultant decrease in PaO2/FiO2 ratio, delayed mobilization, dysfunction of diaphragmatic muscle, and comorbid underlying pulmonary diseases. In order to predict and prevent postoperative pulmonary complications, several types of chest physiotherapy (PT) have been used. However, the effects of chest PT on patient outcome is unclear, since in many hospitals patients are provided with chest PT as a routine modality. In this paper, the effectiveness of chest PT in preventing postoperative pulmonary complications is reviewed, with focus placed on patients who have undergone upper abdominal and cardiac surgery.
Upper Abdominal Surgery
Epidemiology of Pulmonary Complications. The predictive value of preoperative spirometry for postoperative pulmonary complications before abdominal surgery was evaluated by Lawrence and associates with a systematic review and critical appraisal of published literature.1 They found 135 articles relating to this issue. Among these, 22 were actual investigations of the predictive value of preoperative spirometry. They found that all the studies had methodological flaws, and that a lack of validity of routine preoperative spirometry in predicting postoperative pulmonary complications might have an economic impact on hospital cost. They called for further research to prove its positive effect on patient outcomes.
Incidence and hospital stay due to cardiac and pulmonary complications after abdominal surgery were reported by the same group using a case control analysis based on patient record review at a VA hospital in Texas from 1982 to 1991.2 Among 2291 patients who underwent upper abdominal surgery, 96 cases who developed postoperative pulmonary complications were compared to 96 matched controls by operation type and age. Hospital and ICU stays were significantly longer for these cases than for the controls (24.1 vs 10.3 and 5.6 vs 1.5 days, respectively). Pulmonary complications occurred significantly more often than cardiac complications and were significantly associated with longer hospital stays (22.7 vs 10.4 days). Incidences for the entire cohort were 9.6% (95% CI = 7.2-12.0) for pulmonary complications and 5.7% (95% CI = 3.6-7.7) for cardiac complications. From this finding, the study indicated that pulmonary complications were more frequent than cardiac complications and were associated with a longer hospital stay.
Risk Factors of Pulmonary Complications
The risk factors of pulmonary complications after abdominal surgery were also evaluated using the same patient database.3 Preoperative variables associated with postoperative pulmonary complications were evaluated by multivariable analysis. Lawrence et al found that the Charlson comorbidity index (per point OR 1.6, 95% CI 1.004-2.6), Goldman cardiac risk index (per point OR 2.04, 95% CI 1.17-3.6), abnormal chest radiograph (OR 3.2, 95% CI 1.07-9.4), and abnormal findings on chest examination (OR 5.8, 95% CI 1.04-32) were associated with postoperative pulmonary complications. The value of preoperative spirometry including severity of COPD in predicting postoperative pulmonary complications was not confirmed.
The risk of postoperative pulmonary complications in patients with COPD (FEV1 < 50% of predicted) who underwent thoracic and major abdominal surgery was investigated by Kroenke and colleagues.4 A total of 26 patients with postoperative pulmonary complications was compared with 52 patients matched by operation type and age. Incidence of cardiac, pulmonary, and vascular complications were similar between the groups, regardless of mild-moderate COPD. Logistic regression analysis revealed that aging, high ASA score, and use of perioperative bronchodilators were all associated with postoperative complications.
Meta-analysis of Chest PT
Thomas and McIntosh conducted a meta-analysis on the effectiveness of various forms of chest PT on the prevention of postoperative pulmonary complications after upper abdominal surgery.5 They searched literature investigating incentive spirometry (IS), intermittent positive pressure breathing (IPPB), and deep breathing exercise (DBEX) using MEDLINE and the Cumulative Index to Nursing and Allied Health databases from 1966-1992. From 116 citations, 14 articles were used in the meta-analysis. The common odds ratios (CORs) for the above interventions in preventing postoperative pulmonary complications were as follows. (See Table.)
Table
Efficacy of different chest PT modalities in preventing postoperative pulmonary complications
| Intervention |
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| IS vs. No PT |
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| DBEX vs. No PT |
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| IS vs. IPPB |
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| IS vs. DBEX |
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| IPPB vs. DBEX |
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Randomized Controlled Trials of Chest PT
Recently, two RCTs of the use of chest PT in prevention of postoperative pulmonary complications were reported. Hall and associates prospectively randomized 462 patients who underwent abdominal surgery into four groups; IS group with low risk (n = 79), DBEX group with low risk (n = 76), IS group with high risk (n = 152), and IS + PT group with high risk (n = 149).6 Patients with age younger than 60 and an ASA score of 1 were considered to be at low risk. The incidence of respiratory complications was 8% for the IS group with low risk, 11% for the DBEX group with low risk, 19% for the IS group with high risk, and 13% for the IS + PT group with high risk (over all incidence of respiratory complications was 14%). Although no significant difference for incidence of pulmonary complications was found among the groups, the time spent by the physiotherapist was 17, 15, 25, and 55 minutes, respectively, in the four groups.
Another prospective and randomized study was conducted by Olsen and associates, in which 174 patients received chest PT such as pursed lip breathing, huffing and coughing, and early mobilization, and 194 patients received no chest PT.7 Incidences of postoperative pulmonary complications were 6% and 27% for the treatment and control groups, respectively (P < 0.001). Although treated patients were mobilized significantly earlier, no difference in hospital stay was found between the groups.
Summary and Recommendation
The following statements can be made based on the data reviewed above. 1) Preoperative spirometry does not predict postoperative pulmonary complications. 2) Postoperative pulmonary complications are more frequent and associated with a longer hospital stay than cardiac complications. 3) Risk factors for pulmonary complications are aging, comorbid underlying disease (e.g., high ASA score), severity of cardiac disease, abnormal chest x-ray findings, abnormal chest examination, and perioperative use of bronchodilators. Thus, these patients should be a target for providing chest PT. 4) IS and DBEX are confirmed to be more effective in preventing postoperative pulmonary complications than no chest PT. 5) However, a recent RCT failed to prove the effectiveness of IS over DBEX or IS + PT, and although another RCT found advantage in the use of chest PT to no PT, no difference in hospital stay was found. It is concluded that a certain patient population could benefit from chest PT such as IS and DBEX, although further RCTs are required to prove any advantage on hospital stay and cost.
Coronary Artery Bypass Surgery
Coronary artery bypass surgery is one of the most common operations performed in most industrialized countries, and is frequently complicated by postoperative atelectasis. However, the effect of chest PT on morbidity and outcome is still unknown.
Randomized Controlled Trials on Chest PT
Stiller and associates prospectively randomized 120 patients into three groups: Group 1 patients received no perioperative PT; Group 2 had breathing and coughing exercises by a physiotherapist twice daily on the first two postoperative days and once per day on the third and fourth postoperative days; and Group 3 patients received the same intervention, only with the frequency of intervention provided by the physiotherapist doubled.8 The overall incidence of pulmonary complications was 7.5%. No difference was found among the groups in terms of the incidence and severity of fever, hypoxia, chest x-ray abnormalities, and clinically significant pulmonary complications. On the basis of these findings, Stiller et al questioned the prophylactic application of chest PT for routine coronary artery surgery.
Johnson and associates prospectively randomized 228 patients who developed atelectasis postoperatively into four groups, 48 patients with minimal atelectasis receiving early mobilization (Group 1), 49 patients with minimal atelectasis receiving early mobilization and sustained maximal inflation (SMI) (Group 2), those with marked atelectasis receiving early mobilization + SMI (Group 3, n = 64), and those with marked atelectasis receiving early mobilization + SMI + percussion (Group 4, n = 63).9 Johnson et al found that the extent of atelectasis at extubation did not predict the risk of pneumonia. Length of ICU stay and total hospital stay were slightly longer in Groups 3 and 4 in comparison with those of Group 1 and 2: 2.0 and 8, 2.1 and 8, 2.3 and 9, and 2.3 and 10 (mean days), respectively. Physical therapy cost was highest in Group 4 ($79, $88, $100, and $222 per patient in Groups 1-4, respectively). They concluded that although the extent of atelectasis at extubation was related to longer ICU and hospital stays, additional intervention such as SMI and percussion did not improve outcomes such as morbidity and hospital stay, but increased therapist cost.
Similar observation was reported by Richter-Larsen and associates, where 97 low-risk male patients undergoing coronary artery bypass surgery were prospectively randomized into three groups who received routine chest PT, supplemented with positive expiratory pressure, or inspiratory resistance-positive expiratory pressure.10 No difference was found between the groups for physiological measurements and incidence of atelectasis.
Crowe and Bradley enrolled 185 patients with chronic airflow limitation who underwent coronary artery bypass surgery, and randomly assigned them into two groups who received either chest PT (breathing exercise, secretion removal, mobilization) or chest PT with IS.11 They found that chest PT + IS provided patients with no more benefit than chest PT alone.
Summary and Recommendation
Although the presence of marked atelectasis prolongs hospital stay, routine use of chest PT and additional provision of IS or SMI are not validated in terms of improving patient outcomes and should be reevaluated based on hospital cost. Standardization of chest PT in terms of its extent and frequency and definition of pulmonary complications are especially important in conducting future randomized controlled trials in this area.
References
1. Lawrence VA, et al. Arch Intern Med 1989;149:280-285.
2. Lawrence VA, et al. J Gen Inter Med 1995;10:617-618.
3. Lawrence VA, et al. Chest 1996;110:744-750.
4. Kroenke K, et al. Chest 1993;104:1445-1451.
5. Thomas JA, et al. Physical Ther 1994;74:3-16.
6. Hall JC, et al. BMJ 1996;132:148-152.
7. Olsen MF, et al. Brit J Surg 1997;84:1535-1538.
8. Stiller K, et al. Chest 1994;105:741-747.
9. Johnson D, et al. Am J Respir Crit Care Med 1995; 152:953-958.
10. Richter-Larsen K, et al. Intensive Care Med 1995; 21:469-474.
11. Crowe JM, et al. Physical Ther 1997;77:260-268.
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