Systematic oral hydration with water is similar to parenteral hydration for prevention of contrast-induced nephropathy: an updated meta-analysis of randomised clinical data

Background

Contrast-induced nephropathy (CIN) is the third most common cause of hospital-acquired kidney injury and is related to increased long-term morbidity and mortality. Adequate intravenous (IV) hydration has been demonstrated to lessen its occurrence. Oral (PO) hydration with water is inexpensive and readily available but its role for CIN prevention is yet to be determined.

Methods

PubMed, EMBASE and the Cochrane Central register of controlled trials (CENTRAL) databases were searched until April 2015 and studies were selected using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. All randomised clinical trials with head-to-head comparison between PO and IV hydration were included.

Results

A total of 5 studies with 477 patients were included in the analysis, 255 of those receiving PO water. The incidence of CIN was statistically similar in the IV and PO arms (7.7% and 8.2%, respectively; relative risk 0.97; 95% CI 0.36 to 2.94; p=0.95). The incidence of CIN was statistically similar in the IV and PO arms in patients with chronic kidney disease and with normal renal function. Rise in creatinine at 48–72 h was lower in the PO hydration group compared with IV hydration (pooled standard mean difference 0.04; 95% CI 0.03 to 0.06; p<0.001; I²=62%).

Conclusions

Our meta-analysis shows that systematic PO hydration with water is at least as effective as IV hydration with saline to prevent CIN. PO hydration is cheaper and more easily administered than IV hydration, thus making it more attractive and just as effective.

Randomized controlled trial of discontinuation of nasal-CPAP in stable preterm infants breathing room air

This trial assessed the consequences of discontinuation of nasal-CPAP in stable preterm infants breathing room air. Eighty-eight infants with a mean gestational age of 29 (24-33) weeks and a mean birthweight of 1264 (665-2060)g, randomized to either discontinuation of CPAP or its continuation, were clinically observed and monitored for 6 h by cardiorespiratory monitor, pulse oximeter and transcutaneous blood gas monitor. The abdominal circumference and gastric air and aspirate volumes were measured prior to meals at trial entry and after 6 h. Discontinuation of CPAP led to a small but significant decrease in oxygenation at 1 and 6 h. During the trial, five infants in the experimental group required supplemental oxygen and one infant was put back on CPAP owing to excessive apnoeas. Discontinuation of CPAP did not influence the TcPCO2 or the number of apnoeas and bradycardias during the trial, but led to significantly increased respiratory rate, retractions, and flaring at 6 h. It also led to a significant decrease in the abdominal circumference and gastric air volume. Thirty-nine percent of infants were put back on CPAP some time after the trial, mainly because of recurrent apnoeas and bradycardias. Taking the infant off CPAP during the trial reduced subsequent use of CPAP.