###### Abstract  
Background: To report the evaluation of incentive spirometry (IS)-induced pressure changes in intra-abdominal drainage catheters and consider its use for maintaining catheter patency and enhancing drainage. Methods: Prospective study of patients with indwelling intra-abdominal drainage catheters for abdominal fluid collections who had their intra-abdominal pressures measured while performing incentive spirometry. Patients were instructed in the use of an incentive spirometer. Within a week after initial drainage, pressure changes with IS were evaluated three times at 1500 cc and three times at maximum inspiratory effort. Intra-abdominal pressure (IAP) was measured using a pressure monitor connected to the drainage catheter. Results: Twenty patients (men, 12; women, 8). Fluid collection locations were pelvis, Right-upper quadrant (RUQ), Left-upper quadrant (LUQ), Left-lower quadrant (LLQ), and Right-lower quadrant (RLQ). A total of 16 of 20 patients showed an elevation of IAP with IS. At 1500 cc, the pressure increased by an average of 41.24 mmHg2O. At maximal inspiratory effort, the pressure increased by an average of 48.26 mmHg2O. Pressure increase was greater in upper abdomen catheters. Four patients with lower abdominal and pelvic collections showed minimal pressure changes with IS. Conclusion: IS increases IAP and fluid flow through abdominal drainage catheters. Future studies are warranted to determine whether the use of IS enhances catheter performance and facilitates drainage via its effect on IAP.  
incentive spirometry; intra-abdominal fluid collection; percutaneous drainage (\(<\)5%) incidence of complications, depending on the nature of the abscess [12]. Despite its success rates, the drawbacks of PCD include occlusion of catheter side holes, infections, bleeding, and stagnation of fluid flow; the latter of which can be ameliorated by increasing the intra-abdominal pressure relative to the pressure outside the body [12; 14].  
Fluid flows through drainage catheters from inside the body to the external collection bag in a laminar fashion according to Poiseuille's Law \((Q_{\_}{\_}{Laminar}=\frac{(P_{\_}{2}-P_{\_}{1})\approx 2^{4}}{8\eta t}\) ) (Figure 1). A greater pressure differential (\(P_{\_}{2}-P_{\_}{1}\), \(\Delta p\)) and a lower length factor (\(r\)) increase the flow of fluid through the catheter.  
Spirometry breathing exercises cause variations in the intra-abdominal pressure. Increased intra-abdominal pressure is known to augment catheter drainage [15]. The use of incentive spirometry to potentially enhance catheter drainage by increasing intraabdominal pressure has not been studied before. Our study focuses on a novel and potentially impactful use of incentive spirometry to enhance percutaneous catheter drainage. Prior research has shown that increased intra-abdominal pressure can improve catheter drainage, but no prior studies have examined the potential of IS-induced pressure changes to enhance PCD. The purpose of this study is to report the evaluation of incentive spirometry-induced pressure changes in intra-abdominal drainage catheters and consider their use for enhancing drainage; this represents an area of considerable significance since it has the potential to substantially impact clinical practice by optimizing an already-effective procedure in IS.