A Retrospective Study of Anticholinergic Use and Later Mobilization as Risk Factors for Urinary Retention After Major Lower Extremity Joint Arthroplasty.

BACKGROUND: Postoperative urinary retention (POUR) is a common surgical complication of major joint arthroplasty and is associated with increased lengths of stay and urinary tract infections. Studies have found that certain anticholinergic medications and reduced mobility are associated with POUR. This study assessed the effect of anticholinergic burden and later postoperative ambulation on POUR. METHODS: In this retrospective cohort study, we included subjects who had undergone elective primary or revision hip or knee arthroplasty (total hip arthroplasty [THA] or total knee arthroplasty [TKA]) between March 2015 and December 2017 in a single health system. Anticholinergic burden was measured using the Anticholinergic Drug Scale (ADS). We performed bivariate and multivariable logistic regression with POUR as the dependent variable. Of the 1,397 study subjects, 622 (45%) underwent THA and 775 (55%) underwent TKA. Their mean age was 65 years (range, 21 to 98), and 841 (60%) were women. POUR developed in 183 (13%) subjects. RESULTS: In multivariable analyses, ADS was associated with POUR after THA (P < .05), but not TKA (P = .08), while later ambulation was not associated with POUR after either procedure (P > .3 for both). CONCLUSION: Anticholinergic burden after THA was independently associated with POUR. Strategies to reduce anticholinergic burden may help reduce POUR after THA.

Aqueous humor dynamics during the day and night in volunteers with ocular hypertension.

OBJECTIVE: To evaluate the differences in aqueous humor dynamics between nighttime and daytime in participants with ocular hypertension. METHODS: Thirty participants (mean [SD] age, 59.2 [11.1] years) with ocular hypertension were enrolled in the study, which included 1 daytime and 1 nighttime visit. During each visit, measurements included central cornea thickness by ultrasound pachymetry, intraocular pressure (IOP) by pneumatonometry, aqueous flow by fluorophotometry, outflow facility by tonography, and blood pressure by sphygmomanometry. Uveoscleral outflow was calculated using the Goldmann equation. Daytime measurements were made only of episcleral venous pressure by venomanometry, anterior chamber depth by A-scan, and outflow facility by fluorophotometry. Repeated-measures analysis of variance and 2-tailed t tests were used for statistical comparisons. RESULTS: Compared with daytime seated IOP (21.3 [3.5] mm Hg), nighttime seated IOP (17.2 [3.7] mm Hg) was reduced (P < .001) and nighttime supine IOP (22.7 [4.6] mm Hg) was increased (P = .03). Central cornea thickness was increased at night from 570 (39) µm to 585 (46) µm (P < .001). There was a 48% nocturnal reduction in aqueous flow from 2.13 (0.71) µL/min during the day to 1.11 (0.38) µL/min at night (P < .001). Uveoscleral outflow was significantly reduced (P = .03) by 0.61 µL/min at night when using supine IOP, tonographic outflow facility, and episcleral venous pressure adjusted for postural changes in the Goldmann equation. All other measurements had no significant changes. CONCLUSIONS: Significant ocular changes occur at night in individuals with ocular hypertension, including a reduction in seated IOP but an increase in habitual IOP, thickening of the cornea, and decreases in aqueous flow and uveoscleral outflow. Outflow facility does not change significantly at nighttime.

Aqueous humor dynamics during the day and night in juvenile and adult rabbits.

PURPOSE: To determine the day and night differences in intraocular pressure (IOP), aqueous flow, outflow facility, uveoscleral outflow, and central corneal thickness (CCT) in juvenile and adult rabbits. METHODS: Studies were performed on twelve 3-month-old and ten 12-month-old male New Zealand White rabbits. Daytime measurements were made between 9 AM (3 hours after lights on) and 3 PM, and nighttime measurements were made between 11 PM and 5 AM. IOP was measured by pneumotonometry and aqueous flow by fluorophotometry. Outflow facility was determined by both fluorophotometry and tonography. Uveoscleral outflow was calculated by the Goldmann equation. CCT was measured by ultrasound pachymetry. Repeated-measures ANOVAs and Student's two-tailed t-tests were used for statistical comparisons. RESULTS: When nighttime versus daytime readings were compared, IOP, aqueous flow and uveoscleral outflow were higher, fluorophotometric outflow facility was lower, and CCT was thinner in both age groups. When the juvenile rabbits were compared to adult rabbits, IOP was lower, aqueous flow and uveoscleral outflow were higher, and fluorophotometric outflow facility and CCT were not different during the day or night. Tonographic outflow facility did not change in a 24-hour period in the juvenile rabbits. CONCLUSIONS: The increased IOP at night in rabbits can be explained mainly by a decrease in outflow facility. An increase in aqueous flow at night is counterbalanced by an increase in uveoscleral outflow. Although the rates of aqueous flow and uveoscleral outflow slow with maturity, their relative day/night differences remain the same.