MO125: Association of Bladder Post-Void Residual Volume and Urinary Tract Infection in Adult Females
Authors: Maramba Natalie , Patricia Lim Fayanne , Leano Jennifer 
Published: May 2022

Abstract

BACKGROUND AND AIMS
Urinary retention is the inability to voluntarily pass a sufficient amount of urine [1]. This predominantly affects males often due to benign prostatic hyperplasia [1]. In patients with symptomatic urinary retention, initial management such as urethral catheter insertion is warranted, along with further investigation. Multiple complications due to urinary retention include electrolyte imbalance, UTI and renal failure [2, 3]. Prognosis is fair if recognized early and subsequently treated [3]. Currently, there is a lack of standardization in studies involving post-void residual and urinary retention in females [4]. Hence, the aim of this study was to determine if there is a significant association between post-void residual volume estimated by sonography and UTI in symptomatic and asymptomatic adult females. Furthermore, the aim of this study was also to determine the residual volume detected in females with UTI and to describe the patients in terms of age, menopausal status, comorbids and genitourinary profile.

METHOD
The study was a retrospective case-control design with purposive sampling conducted in San Pedro Hospital, Inc., Davao City, Philippines. It involved 430 adult females aged 19 years and above who were admitted from 2018 to 2021 with urinalysis and/or urine culture as well as a pre- and post- void scan result. Factors included that may contribute to UTI were age, presence or absence of diabetes, menopause, hypertension, cerebrovascular accident and anatomic abnormalities and were compared in terms of incidence of UTI between groups. In terms of overall incidence of UTI in relation to % urinary retention, patients were stratified to &lt;10%, 10–30%, 30–50% and &gt;50% retention to identify the minimum amount of retention where the incidence of UTI is significant.

RESULTS
The age range of the 430 female patients included was 19–104 years. Among them, 310 (78.1%) were menopausal, 150 (37.8%) were diabetic, 168 (42.3%) were hypertensive, 7 (1.8%) had cerebrovascular accident and only 3 (0.8%) had anatomic abnormalities. In terms of age, there was no significant difference in the mean age group between those with UTI and without UTI (67 versus 65, P = .091). Between menopausal (72.5% versus 71.2%, P = .388) and non-menopausal groups (18.8% versus 21.6%, P = .759), there was also no statistical difference in the incidence of UTI between groups. The presence of comorbidities such as diabetes (36.3% versus 34.5%, P = .355), hypertension (39.4% versus 39.8%, P = .532), cerebrovascular accident (1.3% versus 1.9%, P = .693) and anatomic abnormalities (0% versus 1.1%, P = .912) likewise did not reach a statistical difference in terms of the presence or absence of UTI.
The relationship of post-void volume and the presence of UTI showed that patients with more than 10% residual volume had higher incidence of UTI (60.4% versus 45.4%), while the majority of those with less than 10% residual volume had lower incidence of UTI (39.6% versus 54.6%). The overall mean residual volume for those with UTI was 27.75 ± 29.38 cc, while the residual volume for those without UTI was 19.70 ± 25.90 cc. This was found to have a significant difference of 8.05 cc (P = .002). The results were further analysed to determine the odds ratio which revealed that those with post-void residual volume of 10% or more had a 27.87% increase in the chance of having UTI (OR = 1.2787, 0.8469–1.9306, P = .242).

CONCLUSION
Symptomatic and asymptomatic adult females with post-void residual volume of more than 10% are at increased risk for UTI regardless of age, menopausal or not, presence or absence of comorbidities. If left undiagnosed, female patients with urinary retention above 10% may then have recurrent UTI. Therefore, further investigation such as urodynamic study or early referral to urogynecologists may be of benefit to confirm and identify the specific cause of bladder dysfunction predisposing to urinary retention in order to incur early intervention and prevention of UTI.