Diclofenac Does Not Decrease Renal Blood Flow or Glomerular Filtration In Elderly Patients Undergoing Orthopedic Surgery

Single-dose diclofenac in healthy volunteers can cause decrease in renal perfusion measured by functional magnetic resonance imaging

OBJECTIVES

We investigated changes of renal perfusion after topical and oral diclofenac administration in healthy volunteers using functional magnetic resonance imaging (MRI) with arterial spin labelling (ASL).

METHODS

Twenty-four healthy human participants (21-51 years) underwent 1.5T MRI before and 1 h after a single oral dose of diclofenac (50 mg). Twelve of 24 participants underwent an additional MRI examination following 3-day topical diclofenac administration. For renal perfusion imaging, a flow-sensitive alternating inversion-recovery TrueFISP ASL sequence was applied. Plasma concentrations of diclofenac and serum concentrations of thromboxane were determined.

KEY FINDINGS

After oral diclofenac application, large interindividual differences in plasma concentrations were observed (range <3-4604 nm). Topical diclofenac application did not result in relevant systemic diclofenac levels (range 5-75 nm). MRI showed a significant reduction of renal perfusion in individuals with diclofenac levels ≥225 nm (baseline: 347 ± 7 vs diclofenac: 323 ± 8 ml/min/100 g, P < 0.01); no significant differences were observed in participants with diclofenac levels <225 nm. Diclofenac levels correlated negatively with thromboxane B2 levels pointing towards target engagement.

CONCLUSIONS

Single-dose diclofenac caused a decrease in renal perfusion in participants with diclofenac levels ≥225 nm. We demonstrated that even a single dose of diclofenac can impair renal perfusion, which could be detrimental in patients with underlying chronic kidney disease or acute kidney injury.

Effects of peri-operative nonsteroidal anti-inflammatory drugs on post-operative kidney function for adults with normal kidney function

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) provide effective analgesia during the post-operative period but can cause acute kidney injury (AKI) when used peri-operatively (at or around the time of surgery). This is an update of a Cochrane review published in 2007.

OBJECTIVES

This review looked at the effect of NSAIDs used in the peri-operative period on post-operative kidney function in patients with normal kidney function.

SEARCH METHODS

We searched Cochrane Kidney and Transplant's Specialised Register to 4 January 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Specialised Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs (RCTs in which allocation to treatment was obtained by alternation, use of alternate medical records, date of birth or other predictable methods) looking at the use of NSAIDs versus placebo for the treatment of post-operative pain in patients with normal kidney function were included.

DATA COLLECTION AND ANALYSIS

Data extraction was carried out independently by two authors as was assessment of risk of bias. Disagreements were resolved by a third author. Dichotomous outcomes are reported as relative risk (RR) and continuous outcomes as mean difference (MD) together with their 95% confidence intervals (CI). Meta-analyses were used to assess the outcomes of AKI, change in serum creatinine (SCr), urine output, renal replacement therapy (RRT), death (all causes) and length of hospital stay.

MAIN RESULTS

We identified 26 studies (8835 participants). Risk of bias was high in 17, unclear in 6and low in three studies. There was high risk of attrition bias in six studies.Only two studies measured AKI. The use of NSAIDs had uncertain effects on the incidence of AKI compared to placebo (7066 participants: RR 1.79, 95% CI 0.40 to 7.96; I2 = 59%; very low certainty evidence). One study was stopped early by the data monitoring committee due to increased rates of AKI in the NSAID group. Moreover, both of these studies were examining NSAIDs for indications other than analgesia and therefore utilised relatively low doses.Compared to placebo, NSAIDs may slightly increase serum SCr (15 studies, 794 participants: MD 3.23 μmol/L, 95% CI -0.80 to 7.26; I2 = 63%; low certainty evidence). Studies displayed moderate to high heterogeneity and had multiple exclusion criteria including age and so were not representative of patients undergoing surgery. Three of these studies excluded patients if their creatinine rose post-operatively.NSAIDs may make little or no difference to post-operative urine output compared to placebo (6 studies, 149 participants: SMD -0.02, 95% CI -0.31 to 0.27). No reliable conclusions could be drawn from these studies due to the differing units of measurements and measurement time points.It is uncertain whether NSAIDs leads to the need for RRT because the certainty of this evidence is very low (2 studies, 7056 participants: RR 1.57, 95% CI 0.49 to 5.07; I2 = 26%); there were few events and the results were inconsistent.It is uncertain whether NSAIDs lead to more deaths (2 studies, 312 participants: RR 1.44, 95% CI 0.19 to 11.12; I2 = 38%) or increased the length of hospital stay (3 studies, 410 participants: MD 0.12 days, 95% CI -0.48 to 0.72; I2 = 24%).

AUTHORS' CONCLUSIONS

Overall NSAIDs had uncertain effects on the risk of post-operative AKI, may slightly increase post-operative SCr, and it is uncertain whether NSAIDs lead to the need for RRT, death or increases the length of hospital stay. The available data therefore does not confirm the safety of NSAIDs in patients undergoing surgery. Further larger studies using the Kidney Disease Improving Global Outcomes definition for AKI including patients with co-morbidities are required to confirm these findings. .

Initial Experience with Narcotic-Free Ureteroscopy: A Feasibility Analysis

BACKGROUND AND PURPOSE

In the United States, there is an opioid abuse epidemic fueled by prescription medications. Concerns that uncontrolled pain after surgical procedures will result in poor patient satisfaction and increased workload for ancillary staff are potential factors that influence provider prescription habits. Currently, there is a paucity of literature on analgesic requirements after ureteroscopy (URS) for nephrolithiasis. Our study objective was to evaluate the safety of narcotic-free ureteroscopy (nf-URS) and assess its impact on provider workload.

METHODS

We performed a retrospective chart review of 104 patients, between October 2017 and May 2018, who underwent URS and who required a stent postprocedure. Starting February 2018, patients without absolute contraindication or allergies to nonsteroidal anti-inflammatory drugs received a prescription for diclofenac instead of hydrocodone or oxycodone. Postoperative phone calls to nurses and residents, emergency room visits, and prescription monitoring reports were evaluated for all patients, and compared between the nf-URS and the standard ureteroscopy (s-URS).

RESULTS

There were 52 nf-URS and 52 s-URS procedures. In the postoperative period, 9 (17%) nf-URS and 10 (19%) s-URS patients called with postoperative pain issues. Five (10%) nf-URS vs 9 (17%) s-URS patients obtained narcotics after seeking additional medical care after URS because of inadequate pain control. There were no postoperative complications in our cohort. Compared with s-URS, 6871.5 mg less of morphine equivalent dosage (1375 hydrocodone tablets) was administered to nf-URS patients immediately after surgery.

CONCLUSIONS

Attempts to reduce the number of narcotic prescriptions are paramount in the fight against narcotic addiction in the United States. Although our initial cohort is small, this feasibility study provides compelling evidence that nf-URS is a safe and effective practice. Furthermore, nf-URS resulted in a dramatic decrease in the number of narcotics circulating in the community.

Low Versus Standard Urine Output Targets in Patients Undergoing Major Abdominal Surgery: A Randomized Noninferiority Trial

OBJECTIVE

To determine whether a low perioperative minimum urine output target is safe and fluid sparing when compared with the standard target.

BACKGROUND

A minimum hourly urine output of 0.5 mL/kg is a key target guiding perioperative fluid therapy. Few data support this standard practice, which may contribute to perioperative fluid overloading.

METHODS

We randomized patients without significant risk factors for acute kidney injury undergoing elective colectomy to a minimum urine output target of 0.2 mL/kg/h (low group) or 0.5 mL/kg/h (standard group) from induction of anesthesia until 8 AM 2 days after surgery. Maintenance fluids were standardized and additional fluids administered to achieve the targets. Primary outcome was noninferiority for urine neutrophil gelatinase-associated lipocalin on the day after surgery.

RESULTS

Between November 21, 2011 and July 11, 2013, 40 participants completed the study. The low group received 3170 mL (95% confidence interval 2380-3960) intravenous fluids versus 5490 mL (95% confidence interval 4570-6410) in the standard group (P = 0.0004), and was noninferior for neutrophil gelatinase-associated lipocalin [14.7 μg/L (interquartile range 7.60-28.9) vs 18.4 μg/L (interquartile range 8.30-21.2); Pnoninferiority = 0.0011], serum cystatin C (Pnoninferiority < 0.0001), serum creatinine (Pnoninferiority = 0.0004), and measured glomerular filtration (Pnoninferiority = 0.0003). Effective renal plasma flow increased in both groups after surgery, and more in the standard group (Pnoninferiority = 0.125).

CONCLUSIONS

A perioperative urine output target of 0.2 mL/kg/h is noninferior to the standard target of 0.5 mL/kg/h and results in a large intravenous fluid sparing. This target should be adopted in surgical patients without significant kidney injury risk factors.

[Risk factors for renal dysfunction after total hip arthroplasty]

INTRODUCTION

Postoperative renal dysfunction (PRD) is well-documented after cardiovascular surgery but there are only limited available data concerning major orthopedic surgery, although patients may have several risk factors prone to impair renal function. We designed an epidemiologic prospective study to assess the incidence of PRD after total hip arthroplasty (THA) and to determine risk factors.

PATIENTS AND METHODS

Were included in the study 755 patients scheduled for THA in a single centre, over a 14 months period. Thirty-one demographic, clinical and biological parameters were collected for each patient. PRD was defined by a value of glomerular filtration, determined by the Cockroft and Gault formula<or=60 ml/min per 1.73 m2, on the seventh postoperative day. Risk factors were determined by univariate and then multivariate analyses using a linear regression model.

RESULTS

Pre- and postoperatively (POD7), respectively 22.4% and 31.4% of the patients, had a creatinine clearance less than 60 ml/min per 1.73 m2. Univariate analysis documented age, ASA score, diabetes mellitus, chronic hypertension, the use of diuretics and NSAID, anemia, and an increased value of plasma urea as risk factors. Risk factors documented by multivariate analysis were: preoperative creatinine clearance less than 60 ml/min per 1.73 m2, (OR: 5.8, 95% confidence interval: [1.6-8.1], p=0.0006), preoperative plasma urea greater than 7.49 mmol/l (2.1 [1.4-11.1], p=0.04), age above 70 years (1.8 [1.1-4.3], p=0.02), and duration of NSAID's treatment beyond 5 days (3.2 [1.4-7.1], p=0.02).

CONCLUSION

PRD is common after THA and is prone to develop in aged patients with comorbidities. Duration of NSAID's administration should be limited in those patients.