You will be provided with the titles and abstracts of a collection of medical RCT reports studying a clinical question -- for instance, the efficacy of an intervention on some medical outcome. Please write a few sentences synthesizing the findings of these reports, which could serve as a conclusion section for a systematic review article. Your response should not include any other text. The RCT reports are below.



Title 1:
Comparison of three methods of respiratory care following upper abdominal surgery.
Abstract 1:
Incentive spirometry, as a method for preventing postoperative atelectasis, was compared with intermittent positive-pressure breathing (IPPB) and resistance breathing in 126 patients undergoing upper-abdominal surgery, most of whom had cholecystectomy. There was no statistically significant difference in the incidence of atelectasis among the three groups, who were matched for age, sex, smoking history, previous respiratory disease, and duration of surgery. There was a significantly higher incidence of atelectasis in patients over the age of 50 years (P = 0.004) than in younger subjects, where the incidence was not different among the three groups. Incentive spirometric therapy, as used in this study, offered no advantage over the other methods of treatment.


Title 2:
A controlled trial of intermittent positive pressure breathing, incentive spirometry, and deep breathing exercises in preventing pulmonary complications after abdominal surgery.
Abstract 2:
Controversy exists regarding the routine use of aids to lung expansion in the prevention of pulmonary complications after abdominal surgery. We prospectively randomized 172 patients into 1 of 4 groups: the control group (44 patients) received no respiratory treatment, the IPPB group (45 patients) received intermittent positive pressure breathing therapy for 15 min 4 times daily, the IS group (42 patients) was treated with incentive spirometry 4 times daily, and the DBE group (41 patients) carried out deep breathing exercises under supervision for 15 min 4 times daily. Roentgenographic changes, observed 24 h after surgery, were comparable in the 4 groups (20.5 to 36.6%). Pulmonary complications were defined as the development of 3 or more of 6 new findings: cough, phlegm, dyspnea, chest pain, temperature greater than 38 degrees C, pulse rate more than 100 beats/min. The frequency of development of pulmonary complications was 48% in the control group, 22% in the IPPB group (p less than 0.05), 21% in the IS group (p less than 0.05), and 22% in the DBE group (p less than 0.05). Side effects of respiratory treatment were observed only in the IPPB group (18%; p less than 0.05). Hospital stay in patients undergoing upper abdominal surgery was significantly shorter in the IS group (mean +/- SD, 8.6 +/- 3 days) than in the control group (13 +/- 5 days). This difference was not observed for the other 2 treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)


Title 3:
Prevention of postoperative pulmonary complications with CPAP, incentive spirometry, and conservative therapy.
Abstract 3:
Continuous positive airway pressure (CPAP) administered at intervals with a mask and incentive spirometry (IS) were compared with a regimen of coughing and deep breathing (CDB) to determine which promoted the most rapid recovery of pulmonary function after upper abdominal operations in 65 adults. Postoperatively, FRC of patients in all groups was similar relative to preoperative values. However, mean FRC of patients who received CPAP increased more rapidly than did mean FRC of those receiving CDB when compared to the values obtained following operation (p less than 0.05). Incentive spirometry did not increase FRC to a greater extent than did CDB. Roentgenographic evidence of atelectasis 72 hours postoperatively was observed in 23 percent of CPAP patients (five of 22) and 42 percent and 41 percent of patients who received CDB (eight of 19) and IS (nine of 22). Two patients (3 percent) developed pneumonia. The low incidence of pneumonia regardless of the type of therapy may be attributable to vigorous, vigilant respiratory care in a population at high risk for developing pneumonia. Frequency and supervision of respiratory therapy may be more important than the type of therapy delivered after upper abdominal operations. Mask CPAP offers advantages because it requires no effort from the patient, and therapy is not painful.


Title 4:
Effects of periodic positive airway pressure by mask on postoperative pulmonary function.
Abstract 4:
Postoperative pulmonary complications, alveolar-arteriolar oxygen difference ([A-a]O2-diff), peak expiratory flow (PEF) and forced vital capacity (FVC) were compared in patients using continuous positive airway pressure (CPAP) and positive expiratory pressure (PEP) administered by face mask against those of a control group using a deep-breathing device (Triflo). Forty-three consecutive, randomized patients undergoing elective upper abdominal surgery were included. CPAP, PEP and Triflo were administered for 30 consecutive breaths in every waking hour for three days postoperatively. The (A-a)O2-difference increased equally and significantly in the three groups after surgery, reaching a maximum on the first postoperative day. After this day, however, (A-a)O2-diff decreased in the CPAP and PEP groups, being significantly lower in the PEP group compared to the control group, two days postoperatively (p less than 0.05) and significantly lower in both the PEP and CPAP groups three days postoperatively (p less than 0.001 and p less than 0.05, respectively.) PEF did not differ significantly between the groups before or after surgery, while FVC was significantly higher in the PEP and CPAP groups, compared to control, on the third postoperative day (p less than 0.05). Atelectatic consolidation was observed in six of 15 patients in the control group three days postoperatively, the incidence being significantly lower in both the PEP group (0 of 15, p less than 0.001) and the CPAP group (one of 13, p less than 0.05). We concluded that periodic face mask administration of CPAP and PEP are superior to deep breathing exercises with respect to gas exchange, preservation of lung volumes and development of atelectasis after upper abdominal surgery. We also conclude that the simple and commercially available PEP mask is as effective as the more complicated CPAP system.


Title 5:
Can postoperative pulmonary conditions be improved by treatment with the Bartlett-Edwards incentive spirometer after upper abdominal surgery?
Abstract 5:
During the immediate postoperative course after upper abdominal surgery, pulmonary complications often occur, caused, inter alia, by reduced regional ventilation and by atelectases as a result of: (1) narrowing of the small peripheral bronchi, and (2) impaired respiratory function. Based on these pathophysiological mechanisms, an instrument (Bartlett-Edwards Incentive Spirometer) has been devised, which aims at giving the patient an opportunity of sustained maximal inspiration under standardized and controlled conditions. The use of this instrument has been followed by reports of a considerable reduction in postoperative pulmonary complications. In a controlled clinical investigation of the pre- and postoperative condition of the lungs, we were unable to show any beneficial effect of the instrument. In general, we have a low frequency of severe postoperative pulmonary complications, as compared with the results reported in the literature. We ascribe this to our very effective pre- and postoperative respiratory therapy.


Title 6:
Absence of benefit of incentive spirometry in low-risk patients undergoing elective cholecystectomy. A controlled randomized study.
Abstract 6:
To determine the potential benefit of incentive spirometry, which has been advocated to prevent pulmonary complications after upper-abdominal surgery, we compared a group of patients receiving incentive spirometry to another group receiving no specialized postoperative respiratory care. Forty patients in the American Society of Anesthesiologists' class 1 and 2 who were undergoing cholecystectomy (through right subcostal incision) were included in the study and were randomly allocated to one of the two groups. Patients receiving incentive spirometry were encouraged by a specialized respiratory physiotherapist to breathe deeply for five minutes hourly, 12 times daily, for three postoperative days. No statistically significant difference between the two groups was found in the radiologic evidence of postoperative pulmonary complications, arterial oxygen pressure, spirometric measurement, and clinical evaluation at the second or fourth postoperative day (or both). In particular, deterioration on the chest x-ray film at the fourth postoperative day was observed in eight of 20 patients in the group receiving incentive spirometry and in six of 20 in the control group. Our study confirms the postoperative deterioration of respiratory function after upper-abdominal surgery and demonstrates the lack of therapeutic values of incentive spirometry in these patients at low risk for pulmonary complications.


Title 7:
An evaluation of the incentive spirometer to improve lung function after cholecystectomy.
Abstract 7:
Forty patients who underwent elective cholecystectomy were allocated randomly to one of two groups. Patients in one group used an incentive spirometer as part of their postoperative chest physiotherapy; those in the other received routine postoperative physiotherapy as dictated by their needs. Each group contained equal numbers of smokers and nonsmokers, and the data from each group were analysed separately. The use of the incentive spirometer did not confer any benefits as judged by clinical evidence of pulmonary complications, pulmonary function tests or length of hospital stay.


Title 8:
Incentive spirometry versus routine chest physiotherapy for prevention of pulmonary complications after abdominal surgery.
Abstract 8:
We entered 876 patients into a clinical trial aimed at preventing pulmonary complications after abdominal surgery. Patients either received conventional chest physiotherapy or were encouraged to perform maximal inspiratory manoeuvres for 5 min during each hour while awake, using an incentive spirometer. The incidence of pulmonary complications did not differ significantly between the groups: incentive spirometry 68 of 431 (15.8%, 95% CI 14.0-17.6%), and chest physiotherapy 68 of 445 (15.3%, CI 13.6-17.0%). Nor was there a difference between the groups in the incidence of positive clinical signs, pyrexia, abnormal chest radiographs, pathogens in sputum, respiratory failure (PO2 less than 60 mm Hg), or length of stay in hospital. We conclude that prophylactic incentive spirometry and chest physiotherapy are of equivalent clinical efficacy in the general management of patients undergoing abdominal surgery.


Title 9:
The evaluation of the incentive spirometer in the management of postoperative pulmonary complications.
Abstract 9:
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We found no evidence regarding the effectiveness of the use of incentive spirometry for prevention of postoperative pulmonary complications in upper abdominal surgery. This review underlines the urgent need to conduct well-designed trials in this field. There is a case for large randomized trials of high methodological rigour in order to define any benefit from the use of incentive spirometry regarding mortality.