Reduced Need for Urinary Bladder Catheterization in the Postanesthesia Care Unit After Implementation of an Evidence-based Protocol: A Prospective Cohort Comparison Study

Preoperative Postvoid Residual Is Not Predictive of Postoperative Urinary Retention in Primary Total Joint Arthroplasty Patients

Background

Postoperative urinary retention is a common complication after total hip and knee arthroplasty. Postvoid residual (PVR) scanning is a noninvasive method commonly used to evaluate this complication. Preoperatively increased PVR (PrePVR) has been suggested as a risk factor for postoperative catheterization. The aim of this study was to prospectively assess the importance of PrePVR and its relationship with urinary catheter placement, urology consult, and length of stay postoperatively.

Methods

Data was prospectively and consecutively collected at a single institution. All patients were bladder scanned preoperatively to collect PrePVR and subsequently scanned on postoperative days zero and one to collect Postoperative PVR. Chart review was performed to determine the number of straight catheterizations, Foley placement, urology consult and length of stay as well as patient demographics.

Results

Ninety-four consecutive patients were included in this study. There was a significantly increased postoperative PVR as compared to PrePVR (48.0 mL vs 21.0 mL; P < .0001). A PrePVR >50 mL was not associated with a significant difference in PVR between before and after surgery (P = .13); length of stay (P = .08); need for straight catheterization (P = .11); postoperative Foley placement (P = 1.0); or urology consult (P = 1.0). The only significant risk factor identified for postoperative Foley catheter placement was age (77.7 vs 64.2; P = .02).

Conclusions

PrePVR >50 mL was not an accurate predictor of postoperative urinary retention after total joint arthroplasty. PVR significantly increased in all patients. Male sex and increasing age were associated with large increases in PVR postoperatively and an increased risk of catheterization.

Routine Use of Bladder Scans After Primary Total Joint Arthroplasty is Not Necessary: Results of a Protocol Change

BACKGROUND

Postoperative urinary retention is a common concern after total joint arthroplasty (TJA) and can cause discomfort, incontinence and, if left untreated, myogenic changes to the bladder. However, overdiagnosis of postoperative urinary retention by bladder scans may lead to unnecessary interventions and delayed discharges. The purpose of this study was to compare the safety of two bladder management protocols following TJA.

METHODS

From January 3, 2022 to April 29, 2022, 519 consecutive patients operated on by thirteen surgeons underwent routine postoperative bladder scanning (standard protocol). From February 28, 2022 to April 29, 2022, a new protocol was introduced by three surgeons in 209 consecutive patients using a specific algorithm (selective protocol) so that only symptomatic patients had bladder scans. The primary outcome of interest was catheterization rate. Chi-square and Students t-tests were used for analyses. There were 37.7% of patients in the selective group who received scans.

RESULTS

Times to catheterization, readmissions, emergency department visits, and straight catheterization rates (15.0 versus 14.8% P = .999) were similar. More scans in the selective group resulted in intervention (39.2 versus 15.0%, P < .001). Prevoid volumes were higher in the selective protocol (608 versus 448 mL, P < .001). Postvoid volumes were similar (233 versus 223 mL, P = .497). There was one readmission for a urinary tract infection in the standard group and no urinary-related readmissions in the selective group.

CONCLUSION

The selective protocol had a higher rate of same day discharge, fewer bladder scans, and did not lead to increased rates of urinary-related complications. These findings suggest that selective bladder scanning for symptomatic patients can be safely instituted for TJA patients.

Validation of acoustic voided volume measure: a pilot prospective study

PURPOSE

We evaluated the accuracy and reliability of a new smartphone-based acoustic voided volume (VV) measurement application compared to VV estimation based on the measurement of urine volume in a bladder by ultrasound bladder scan.

PATIENTS AND METHODS

A total of 53 subjects from 01/2021 to 09/2021 were prospectively enrolled. Bladder scan-based VV estimation is based on the difference in the volume of urine in a bladder measured before urination and volume measured after urination. The acoustic VV measurement is based on smartphone-based acoustic VV measurement mobile application. VV estimates for the same void were compared between two techniques. Urinary measures were obtained from 49 male subjects resulting in a total of 245 measurements for analysis. VV measures were compared using Pearson's correlation coefficient (PCC), evaluation of observed versus predicted VV measures using linear regression fit indices, and Bland-Altman method.

RESULTS

VV between the two techniques revealed strong correlation (PCC 0.811, p < 0.001). Means of the number of measurements per patient and inpatient days for measurements analyzed are 5 and 2.7, respectively. In 245 measurements, VV measured by bladder scan is 238.69 ± 122.32 mL, VV measured by mobile application is 254.69 ± 119.28 mL, and their difference of two measurements is 16 ± 74.29 mL.

CONCLUSION

Through the comparison with VV estimated by ultrasound bladder scan, which is a technology to measure the urine volume in a bladder, it was confirmed that the smartphone-based acoustic VV measurement application proudP^® is accurate.

Bypassing the post‐anaesthesia care unit after elective hip and knee arthroplasty: a prospective cohort safety study

Following knee and hip arthroplasty, transfer to a recovery area immediately following surgery and before going to ward might be unnecessary in low-risk patients. Avoiding the recovery area in this way could allow for more targeted use of resources for higher risk patients, which may improve operating theatre flow and productivity. A prospective single-centre cohort study on the safety of criteria for bypassing the post-anaesthesia care unit in elective hip and knee arthroplasty was designed. Criteria were: ASA physical status < 3; peri-operative bleeding < 500 ml; low postoperative discharge-score (modified Aldrete-score); and an uncomplicated surgical and neuraxial anaesthesia procedure. The primary outcome was the number of patients in need of secondary readmission to the post-anaesthesia care unit. Events within the first 24 postoperative hours were recorded, along with readmission and complication rates. A total of 696 patients were included, with 287 (41%) undergoing total hip arthroplasty, 274 (39%) undergoing total knee arthroplasty and 135 (19%) undergoing unicompartmental knee-arthroplasty. Of these, 207 (44%) bypassed the post-anaesthesia care unit. Patients all received multimodal analgesia without peripheral nerve blockade. Only one patient in the ward group required secondary readmission to the post-anaesthesia care unit. Within 24 h, 151 events were reported, with 41 (27%) in the ward group and 110 (73%) in the post-anaesthesia care unit group. Two events in each group occurred within 2 hours of surgery. No complications were attributed to bypassing the post-anaesthesia care unit. The use of simple pragmatic criteria for bypassing the post-anaesthesia care unit for patients undergoing knee and hip arthroplasty with spinal anaesthesia is possible and associated with significant reduction of post-anaesthesia care unit admission and without apparent safety issues. Confirmation is needed from other studies and external validity should be interpreted cautiously in centres with different peri-operative regimens, organisational and staffing structures.