Volume Incentive Spirometry Reduces Pulmonary Complications in Patients After Open Abdominal Surgery: A Randomized Clinical Trial

Introduction

More than 300 million surgical procedures are performed every year worldwide, and abdominal surgery is the most frequent major surgery.1,2 Postoperative pulmonary complications (PPCs) following abdominal surgery are frequent with an incidence ranging from 1% to 30%.3 The risk of PPCs increases with the distance from the surgical site to the diaphragm. Due to this unique physiological mechanism, upper abdominal incisions are associated with a higher risk of PPCs than lower abdominal surgeries.3 Common PPCs include atelectasis, pneumonia, and hypoxemia partially caused by diaphragm dysfunction, impaired mucociliary clearance, and postoperative pathophysiological reductions in lung volumes such as a reduction in the forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1).4,5 It has been demonstrated that obesity, smoking, malnutrition, and old age were associated with the incidence of PPCs among those undergoing abdominal surgery. Besides, the anesthesia, the surgical technique, the type of incision, and ineffective coughing might also contribute to PPC development.6 PPCs increase the morbidity and mortality rate, the length of hospital stay, readmissions, and additional healthcare costs.7 Therefore, to take effective measures for the prevention of PPCs after abdominal surgeries are urgently needed.

Since the beginning of the 20th century, respiratory physical therapy is often used for PPCs prevention and treatment to strengthen ventilation-perfusion matching and increase lung volumes and airway clearance.8 It consists of various airway clearance techniques and lung expansion therapy including diaphragmatic breathing exercises, mobilization, and mechanical breathing devices such as incentive spirometry.9 Diaphragmatic breathing exercise increases diaphragmatic excursion, alveolar expansion, and ventilation, reducing the chance of hypoxemia and an increase in respiratory work.10 Incentive spirometry is designed to give positive feedback and enables the patient to take long, slow deep breaths imitating natural sighing.11 It is available in two types: flow incentive spirometry (FIS) and volume incentive spirometry (VIS).11 A previous study has compared the effect of FIS and VIS on pulmonary function in abdominal surgery and found that VIS had a superior ability to FIS in reducing hospital stay.12 Additionally, Sum et al revealed that incentive spirometer reduced PPCs in patients with traumatic rib fractures.13 However, there is a lack of comprehensive research comparing diaphragmatic breathing with VIS in subjects after abdominal surgeries. In this study, we divided patients into the control (receiving diaphragmatic breathing exercises) and VIS (performing VIS exercises) groups to compare the hemodynamics, pulmonary function, and blood gas. Understanding the different effects of the two exercises might aid in recovery planning for patients after open abdominal surgeries.

Materials and Methods Participants

This prospective and randomized study was conducted in the Department of Surgery, Haining People’s Hospital between August 2021 and September 2022. Ethics approval was obtained from the Institutional Ethics Committee (IEC HPH 221008). All participants signed the written informed consent. Inclusion criteria: (1) patients received open abdominal surgery under general anesthesia; (2) with a medium or high risk of postoperative pulmonary complications (“Assess Respiratory Risk in Surgical Patients in Catalonia, ARISCAT score” ≥ 26);14 (3) patients who did not stay in intensive care unit after an operation and returned to ward successfully after extubation; (4) good compliance and understanding ability, able to cooperate with the completion of perioperative pulmonary rehabilitation treatment. Finally, 58 participants met the criteria and participated in this study. All the participants were randomly divided into the control group (n=29) and the VIS group (n=29) (Figure 1). The allocation sequence was computer-generated by a statistician and blinded to the investigators. Participants were randomized at a ratio of 1:1. The outcome assessor was also blinded to the group assignment.

Figure 1 Consort flow chart.

Intervention

In the control group, participants received conventional diaphragmatic breathing exercises. The participants were placed in a half-lying position and their hands were placed just below the anterior costal margin, on the rectus abdominus muscle, and inhaled slowly through the nose for 3 seconds, from functional remaining capacity to total lung capacity. Exhalation was performed slowly through the mouth. They were asked to relax their shoulders and upper chest so they could feel the rise and fall of their abdomen with the hand resting on it.15 The method of performing diaphragmatic breathing exercises is shown in Figure 2A. The exercises were performed for 5 minutes and 4 times per day under the supervision of the therapist. They were asked to breathe normally in between the sets of the diaphragmatic breathing exercise.11

Figure 2 Two intervention exercises for patients following abdominal surgery. (A) Diaphragmatic breathing. (B) Volume incentive spirometry.

In the VIS group, VIS was administered to the patient who was also placed in a half-lying position. A pillow was placed beneath the patient’s knees. The participants were instructed to hold the volume-oriented incentive spirometry and perform slow, deep inhalation, avoiding any forceful expiration.16 The process was first demonstrated to the patient to ensure that they understood the technique’s use before performing it. The method of performing VIS is shown in Figure 2B. The treatment was performed for 5 minutes and 4 times per day under the supervision of the therapist. Both two groups received routine postoperative rehabilitation education before surgery and began to receive treatment guidance 2 days before surgery.

Data Collection

After being allotted into groups, the patients in the two groups were visited one day before the surgery. Demographic data such as age, height, weight, body mass index (BMI), sex, smoking history, and type of surgery were collected.

Six-minute walk test (6MWT): The patients performed a 6MWT according to the American Society’s guidelines during the preoperative period.17 Dyspnoea and fatigue, mean arterial pressure (MAP), heart rate (HR), and oxygen saturation (SpO2) were measured at the start and immediately after finishing the test. A modified Borg scale was used to measure dyspnoea and fatigue. Distance covered in meters after 6 minutes was the main outcome of the test.

All the subjects underwent evaluations of hemodynamic indexes including MAP, HR, and SpO2 were also recorded on the 1st, 3rd, and 5th postoperative days for both groups. The primary outcome measurements were changes to pulmonary function through the following parameters: maximal inspiratory pressure (MIP), peak expiratory flow (PEF), vital capacity max (Vcmax), FEV1, FVC, and FEV1/FVC. In addition, blood gas indexes such as bass excess (BE), partial pressure of arterial oxygen (PaO2), partial pressure of arterial carbon dioxide (PaCO2), and pH values were recorded. These measurements were taken in the preoperative period and were repeated on the 1st, 3rd, and 5th postoperative days for both groups.

Statistical Analysis

All data analyses were performed by SPSS software version 23.0 (SPSS Inc., Chicago, IL, USA). Categorical variables were represented as count (percentage) and the difference between the two groups was compared by Chi-square test or Fisher’s exact test. Continuous variables conforming to normal distribution were expressed as mean ± standard deviation (SD) and an independent t-test was used to compare differences between the two groups, and repeated-measure analysis of variance was used for intra-group comparisons. Non-normally distributed continuous data were expressed as median (quartile) and were compared by Mann–Whitney U-test between the two groups. Statistical significance was set at P <0.05. The effect size of the study was calculated as 0.80 using G*Power software version 3.1.9.7 (Franz Faul, Universitat Kiel, Germany) based on the two-sided significance level (α), sample size (n=29 in each group), power (1-β=0.85), and independent t-test.

Results Demographic Information

Fifty-eight patients (including 41 males and 17 females) who received open abdominal surgery under general anesthesia were included in the study. The control group and the VIS group consisted of 29 patients each. There were no dropouts in this study. Their average age was 72.81±9.86 years (control group 72.00 ± 9.62; VIS group 73.62 ± 10.21; P >0.05). There were no significant differences in height, weight, and BMI between the two groups (all P >0.05). Males accounted for 72.4% and 69.0%, respectively in the control and VIS groups with no statistical difference (P >0.05). The number of patients having a smoking history was 19 (65.5%) and 15 (51.7%) in the control and VIS groups, respectively (P >0.05). Besides, the distribution of type of surgery in the control group was not significantly different from that in the VIS group (Table 1).

Table 1 Demographic Characteristics

Comparison of Functional Capacity Between the Two Groups Preoperatively

The functional capacity of patients was measured using a 6MWT preoperatively and was compared between the two groups. No significant difference was observed in the distance walked between the two groups. Additionally, the pre-test modified Borg score, MAP, HR, and SpO2, as well as the post-test modified Borg score, MAP, HR, and SpO2 in the two groups were not significantly different (all P >0.05) (Table 2).

Table 2 Comparison of Functional Capacity Between the Two Groups Preoperatively

Comparison of Hemodynamics Inter and Intra-Group Differences at Different Time Points

Three hemodynamic indexes MAP, HR, and SpO2 were compared with the control and VIS groups 1, 3, and 5 days after the operation. When compared with the 1st postoperative day, there was a statistically significant increase seen in the MAP on the 3rd and 5th days within the two groups (all P <0.05). There was a statistically significant decrease in HR on the 3rd postoperative day compared with the 1st postoperative day (P <0.05). However, there was no significant change in SpO2 postoperatively (P >0.05). Besides, at 3 days and 5 days after the operation, patients in the VIS group had a significantly higher SpO2 than that in the control group (all P <0.05) (Table 3).

Table 3 Comparison of Hemodynamics Inter and Intra-Group Differences at Different Time Points

Comparison of Pulmonary Function Inter and Intra-Group Differences at Different Time Points

No significant difference in MIP, PEF, Vcmax, FEV1, FVC, and FEV1/FVC between the control and VIS groups was found during the preoperative period (P >0.05). Compared with the preoperative period, MIP, PEF, Vcmax, FEV1, FVC, and FEV1/FVC were significantly decreased on the 1st, 3rd, and 5th postoperative day within both control and VIS groups (all P <0.05). However, there was an increasing trend in these six indexes on the 3rd and 5th postoperative days compared with the 1st postoperative day. Moreover, the VIS group had a significantly higher value of MIP than the control group on the 1st and 5th days after the operation (P <0.05). The Vcmax value was significantly higher in the VIS group on the 3rd and 5th postoperative days than that in the VIS group (P <0.05). The significantly elevated levels of PEF, FEV1, FVC, and FEV1/FVC were observed on the 1st, 3rd, and 5th postoperative days in the VIS group compared with those in the control group (all P <0.05) (Table 4).

Table 4 Comparison of Pulmonary Function Test Inter and Intra-Group Differences at Different Time Points

Comparison of Blood Gas Indexes Inter and Intra-Group Differences at Different Time Points

There was no statistical difference in preoperative blood gas indexes between the two groups. Compared with the preoperative period, BE, PaO2, and pH were significantly downregulated on the 1st and 3rd days after the operation within the two groups (P <0.05). The level of PaCO2 was significantly upregulated on the 1st and 3rd postoperative days compared to the preoperative period (P <0.05). In the VIS group, BE, and pH were significantly higher on the 1st postoperative day than those in the control group (P <0.05), while there was no statistical significance in PaO2 and PaCO2 levels between the two groups (P >0.05) (Table 5).

Table 5 Comparison of Blood Gas Indexes Inter and Intra-Group Differences at Different Time Points

Discussion

With a large number of surgeries occurring annually worldwide, morbidity and mortality are increased in patients who develop PPCs.18 PPCs such as respiratory failure, and pneumonia are common following abdominal surgery, leading to a prolonged hospital stay and decreased postoperative stay.19 This study compared the efficacy of conventional diaphragmatic breathing and the VIS on hemodynamics, pulmonary function, and blood gas indexes in patients undergoing open abdominal surgery under general anesthesia. The study enrolled 58 participants with an average age of 72.81±9.86 years. The patients were randomly assigned to the control group receiving the diaphragmatic breathing exercise (n=29) and the VIS group (n=29). Our study indicated that VIS might be a valuable treatment option for use with patients after open abdominal surgeries for improving pulmonary function, hemodynamics, and blood gas indexes.

Many risk factors have been identified to be associated with PPCs. Smoking is a risk factor for pulmonary complications after surgery, even in patients with the absence of lung disease.20 The underlying mechanism might be decreased lung capacity and impaired mucociliary function due to tobacco-induced organ damage.21 In addition, older age was associated with a higher risk of PPCs and poor survival rates since they are at an increased risk of comorbid conditions.22 Congestive heart failure, a diagnosis of chronic obstructive pulmonary disease, an ASA score of II or higher, or chronic liver disease were independent risk factors for PPCs.5,23–25 Kaw et al showed that patients with obstructive sleep apnoea have a two-fold increase in the risk of developing acute respiratory failure after non-cardiac surgery.26 In addition, patients with preoperative anemia undergoing any type of surgery are more than triple as likely as those without anemia to develop a PPC.27

The administration of anesthesia leads to ventilation-perfusion mismatch, hypoxemia, and shunt. The hypoxic ventilator drive and the normal periodic “sighing” respiration which are necessary for the maintenance of normal lung inflation are suppressed by narcotic analgesics and anesthetic agents.28 Narcotic analgesics affect the central regulation of respiration, altering the upper respiratory tract and chest wall, resulting in inadequate ventilation, reduced sensitivity of the respiratory center to carbon dioxide stimulation, increased obstructive breathing, suppression of the cough reflex, and irregular mucus production.10 Direct injuries to the abdominal wall and incisions affect diaphragm function. All these factors can impair the function of respiratory muscles, leading to a decrease in functional residual capacity and vital capacity.29 In this study, the functional capacity of the patients preoperatively was assessed by 6MWT and the results showed that there was no significant difference in all the related indicators including walk distance, Borg-score, MAP, HR, and SpO2 between the two groups. However, SpO2 in the VIS group was significantly higher than that in the control group on the 3rd and 5th postoperative day, indicating that postoperative hypoxemia was reduced by using VIS.

FEV1, FVC, and FEV1/FVC are useful parameters for evaluating restrictive lung disease. PEF is a measure of maximum flow or peak flow generated by maximum effort on exhalation and it assesses maximum expiratory as an alternative measure of expiratory muscle strength and is useful for evaluating obstructive pulmonary disease such as asthma.30 The pulmonary function test values such as PEF, FEV1, FVC, and FEV1/FVC ratio were all significantly downregulated after abdominal surgery compared with those during the preoperative period. As a mechanical device, VIS was used to encourage patients to take long, slow, and sustained deep inspirations which contribute to achieving maximal inflating pressure in the alveoli and maximal inhaled volume, and also helps to maintain the patency of the smaller airways.11 There is an increasing trend of these values after diaphragmatic breathing exercises and VIS exercises on the 3rd and 5th postoperative day. As expected, patients in the VIS group had significantly higher levels of FEV1, FVC, FEV1/FVC, MIP, PEF, and Vcmax compared with the control group. Moreover, we found that BE and pH values were higher in the VIS group within the normal range than those in the control group. These findings revealed that VIS exercise might have a superior ability to the conventional diaphragmatic breathing exercise in improving pulmonary function.

In conclusion, the functional capacity of the patients in the two groups was not statistically different before the surgery. There was a significant improvement in hemodynamics, pulmonary function, and blood gas for patients following open abdominal surgery in the VIS group to the control group. Thus, diaphragmatic breathing and VIS could improve pulmonary function postoperatively, but VIS exercise might be a better option for lowering the incidence of PPCs.

Data Sharing Statement

The dataset used and/or analyzed during the current study is available from the corresponding author on reasonable request.

Ethics Approval

The study was approved by Haining People’s Hospital. All patients who were familiar with the contents and processes of the study and able to complete all the scheduled study processes signed the informed consent. Our study complies with the Declaration of Helsinki.

Funding

No funding was received for conducting this study.

Disclosure

The authors have no conflicts of interest to declare for this work.

References

1. Asehnoune K, Le Moal C, Lebuffe G, et al. Effect of dexamethasone on complications or all cause mortality after major non-cardiac surgery: multicentre, double blind, randomised controlled trial. BMJ. 2021;373:n1162. doi:10.1136/bmj.n1162

2. Boden I, Skinner EH, Browning L, et al. Preoperative physiotherapy for the prevention of respiratory complications after upper abdominal surgery: pragmatic, double blinded, multicentre randomised controlled trial. BMJ. 2018;360:j5916. doi:10.1136/bmj.j5916

3. Huang YT, Lin YJ, Hung CH, et al. The fully engaged inspiratory muscle training reduces postoperative pulmonary complications rate and increased respiratory muscle function in patients with upper abdominal surgery: a randomized controlled trial. Ann Med. 2022;54(1):2222–2232. doi:10.1080/07853890.2022.2106511

4. Koc A, Inan G, Bozkirli F, Coskun D, Tunc L. The evaluation of pulmonary function and blood gas analysis in patients submitted to laparoscopic versus open nephrectomy. Int Braz J Urol. 2015;41(6):1202–1208. doi:10.1590/S1677-5538.IBJU.2015.0040

5. Miskovic A, Lumb AB. Postoperative pulmonary complications. Br J Anaesth. 2017;118(3):317–334. doi:10.1093/bja/aex002

6. Cleva R, Assumpcao MS, Sasaya F, et al. Correlation between intra-abdominal pressure and pulmonary volumes after superior and inferior abdominal surgery. Clinics. 2014;69(7):483–486. doi:10.6061/clinics/2014(07)07

7. Kuroe Y, Mihara Y, Okahara S, Ishii K, Kanazawa T, Morimatsu H. Integrated pulmonary index can predict respiratory compromise in high-risk patients in the post-anesthesia care unit: a prospective, observational study. BMC Anesthesiol. 2021;21(1):123. doi:10.1186/s12871-021-01338-1

8. Stiller KR, Munday RM. Chest physiotherapy for the surgical patient. Br J Surg. 1992;79(8):745–749. doi:10.1002/bjs.1800790807

9. Rowley DD, Malinowski TP, Di Peppe JL, Sharkey RM, Gochenour DU, Enfield KB. A randomized controlled trial comparing two lung expansion therapies after upper abdominal surgery. Respir Care. 2019;64(10):1181–1192. doi:10.4187/respcare.06812

10. Alaparthi GK, Augustine AJ, Anand R, Mahale A. Comparison of diaphragmatic breathing exercise, volume and flow incentive spirometry, on diaphragm excursion and pulmonary function in patients undergoing laparoscopic surgery: a randomized controlled trial. Minim Invasive Surg. 2016;2016:1967532. doi:10.1155/2016/1967532

11. Amin R, Alaparthi GK, Samuel SR, Bairapareddy KC, Raghavan H, Vaishali K. Effects of three pulmonary ventilation regimes in patients undergoing coronary artery bypass graft surgery: a randomized clinical trial. Sci Rep. 2021;11(1):6730. doi:10.1038/s41598-021-86281-4

12. Kumar AS, Alaparthi GK, Augustine AJ, Pazhyaottayil ZC, Ramakrishna A, Krishnakumar SK. Comparison of flow and volume incentive spirometry on pulmonary function and exercise tolerance in open abdominal surgery: a randomized clinical trial. J Clin Diagn Res. 2016;10(1):KC01–KC06. doi:10.7860/JCDR/2016/16164.7064

13. Sum SK, Peng YC, Yin SY, et al. Using an incentive spirometer reduces pulmonary complications in patients with traumatic rib fractures: a randomized controlled trial. Trials. 2019;20(1):797. doi:10.1186/s13063-019-3943-x

14. Girrbach F, Zeutzschel F, Schulz S, et al. Methods for determination of individual PEEP for intraoperative mechanical ventilation using a decremental PEEP trial. J Clin Med. 2022;11(13):3707. doi:10.3390/jcm11133707

15. Alaparthi GK, Amin R, Gatty A, et al. Contrasting effects of three breathing techniques on pulmonary function, functional capacity and daily life functional tasks in patients following valve replacement surgery- a pilot randomized clinical trial. Heliyon. 2021;7(7):e07643. doi:10.1016/j.heliyon.2021.e07643

16. Restrepo RD, Wettstein R, Wittnebel L, Tracy M. Incentive spirometry: 2011. Respir Care. 2011;56(10):1600–1604. doi:10.4187/respcare.01471

17. Laboratories ATSCoPSfCPF. ATS statement: guidelines for the six-minute walk test. Am J Respir Crit Care Med. 2002;166(1):111–117. doi:10.1164/ajrccm.166.1.at1102

18. Karalapillai D, Weinberg L, Neto AS, et al. Intra-operative ventilator mechanical power as a predictor of postoperative pulmonary complications in surgical patients: a secondary analysis of a randomised clinical trial. Eur J Anaesthesiol. 2022;39(1):67–74. doi:10.1097/EJA.0000000000001601

19. Sand O, Andersson M, Arakelian E, Cashin P, Semenas E, Graf W. Severe pulmonary complications after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy are common and contribute to decreased overall survival. PLoS One. 2021;16(12):e0261852. doi:10.1371/journal.pone.0261852

20. Lo IL, Siu CW, Tse HF, Lau TW, Leung F, Wong M. Pre-operative pulmonary assessment for patients with hip fracture. Osteoporos Int. 2010;21(Suppl 4):S579–S586. doi:10.1007/s00198-010-1427-7

21. Gronkjaer M, Eliasen M, Skov-Ettrup LS, et al. Preoperative smoking status and postoperative complications: a systematic review and meta-analysis. Ann Surg. 2014;259(1):52–71. doi:10.1097/SLA.0b013e3182911913

22. Wu CY, Cheng YJ, Hung MH, Lin IJ, Sun WZ, Chan KC. Association between early acute respiratory distress syndrome after living-donor liver transplantation and perioperative serum biomarkers: the role of club cell protein 16. Biomed Res Int. 2019;2019:8958069. doi:10.1155/2019/8958069

23. Brueckmann B, Villa-Uribe JL, Bateman BT, et al. Development and validation of a score for prediction of postoperative respiratory complications. Anesthesiology. 2013;118(6):1276–1285. doi:10.1097/ALN.0b013e318293065c

24. Li C, Yang WH, Zhou J, et al. Risk factors for predicting postoperative complications after open infrarenal abdominal aortic aneurysm repair: results from a single vascular center in China. J Clin Anesth. 2013;25(5):371–378. doi:10.1016/j.jclinane.2013.01.013

25. Canet J, Sabate S, Mazo V, et al. Development and validation of a score to predict postoperative respiratory failure in a multicentre European cohort: a prospective, observational study. Eur J Anaesthesiol. 2015;32(7):458–470. doi:10.1097/EJA.0000000000000223

26. Kaw R, Chung F, Pasupuleti V, Mehta J, Gay PC, Hernandez AV. Meta-analysis of the association between obstructive sleep apnoea and postoperative outcome. Br J Anaesth. 2012;109(6):897–906. doi:10.1093/bja/aes308

27. Canet J, Gallart L, Gomar C, et al. Prediction of postoperative pulmonary complications in a population-based surgical cohort. Anesthesiology. 2010;113(6):1338–1350. doi:10.1097/ALN.0b013e3181fc6e0a

28. Navarro KL, Huss M, Smith JC, Sharp P, Marx JO, Pacharinsak C. Mouse anesthesia: the art and science. ILAR J. 2021;62(1–2):238–273. doi:10.1093/ilar/ilab016

29. Stocking JC, Drake C, Aldrich JM, et al. Outcomes and risk factors for delayed-onset postoperative respiratory failure: a multi-center case-control study by the University of California critical care research collaborative (UC(3)RC). BMC Anesthesiol. 2022;22(1):146. doi:10.1186/s12871-022-01681-x

30. Choi JY, Rha DW, Park ES. Change in pulmonary function after incentive spirometer exercise in children with spastic cerebral palsy: a randomized controlled study. Yonsei Med J. 2016;57(3):769–775. doi:10.3349/ymj.2016.57.3.769

留言 (0)

沒有登入
gif