Abstract: Objective:To investigate the application value of high frequency chest wall oscillation (HFCWO) after operation of abdominal incisional hernia.
Methods:A prospectively randomized doubleblind study was adopted. Fifty patients who underwent operation of abdominal incisional hernia at the Huadong Hospital Affiliated to Fudan University between January 2014 and September 2015 were allocated into the HFCWO group (undergoing postoperative HFCWO) and control group ［undergoing postoperative conventional chest physiotherapy (CPT )］ using random number table. Observation indicators included: (1) adverse events, (2) pain perception index: postoperative pain intensity from 1 day to 5 days was assessed by visual analogue scale (VAS), (3) respiratory function: arterial oxygen saturation (SaO2), oxygenation index (OI), arterial partial pressure of oxygen (PaO2) and arterial partial pressure of carbon dioxide (PaCO2) at postoperative day 1, 3 and 5, (4) followup. The followup using outpatient examination and telephone interview was performed to detect the recovery of patients up to March 2016. Measurement data with normal distribution were represented as ±s. The comparisons between groups were evaluated with the t test. The repeated measurement data were done using the repeated measures ANOVA and the count data were analyzed using the chisquare test.
Results:Fifty patients were screened for eligibility and were allocated into the 2 groups, 25 in each group. (1) Adverse events: all the patients in the 2 groups underwent successfully treatment, without the occurrence of hypoxemia, hemodynamic instability, arrhythmia, bronchospasm, vomiting, wound dehiscence, shedding catheter and so on. (2) Pain perception index: VAS from before chest treatment to postoperative day 5 was from 1.7±1.0 to 1.5±1.1 in the HFCWO group and from 1.4±0.8 to 1.8±0.6 in the control group, with a statistically significant difference in the change trend of pain intensity between the 2 groups (F=0.02, P<0. 05) and in the pain intensity at postoperative day 2, 3 and 4 between the 2 groups (t= 0.01, 0.01, 0.01, P<0. 05). (3) Respiratory function: arterial SaO2, OI and arterial PaO2 from before chest treatment to postoperative day 5 was from 97.9%±2.2% to 99.2%±0.9%, from (300±47)mmHg (1 mmHg=0.133 kPa) to (337±59)mmHg, from (103±49)mmHg to (104±17)mmHg in the HFCWO group and from 98.2%±2.3% to 98.8%±2.0%, from (311±29)mmHg to (347±61)mmHg, from (99±15)mmHg to (103±14)mmHg in the control group, with statistically significant differences in the change trends of above indicators between the 2 groups (F=0.83, 0.50, 0.59, P>0. 05). (4) Followup: 43 patients were followed up after discharge from hospital for 1-6 months, with a median time of 5 months. During the followup, patients were not complicated with chest tightness and shortness of breath, with good wound healing.
Conclusion:Compared with conventional chest physiotherapy, HFCWO could improve tolerability of patients and reduce the pain after operation of abdominal incisional hernia.