Comparison of Oral and Intravenous N-acetyl Cysteine in Preventing Contrast Nephropathy

Introduction

Despite high rates of morbidity and mortality in patients with contrast-induced nephropathy (CIN), there is no consensus regarding prevention of this well-known complication of contrast media use. One agent that has been widely used in this regard is N-acetyl cysteine (NAC). Nevertheless, its efficacy is still controversial. The aim of this study was to assess the efficacy of NAC, both in the oral and intravenous forms, for the prevention of CIN.

Methods

This study is a double-blind randomized placebo controlled clinical trial. We randomized 434 adult patients with chronic kidney disease (constant serum creatinine ≥1.5 mg/dL) who were candidates for coronary angiography/plasty. The patients were categorized into three groups. One group received 1,200 mg NAC intravenously half an hour before the procedure and oral placebo starting 3 days before angiography. The second group received oral NAC 600 mg twice daily for 3 days, starting the day before the intervention and intravenous placebo half an hour before intervention. The third group received both oral and intravenous placebo. CIN was defined as a 25% relative increase in serum creatinine from baseline value, 48 h after use of contrast medium.

Results

Of the 434 patients, 149 received intravenous NAC, 145 received oral NAC, and the remaining 140 received placebo. The incidence of CIN in the three groups was 6.1%, 7.6%, and 10.8%, respectively (p = 0.34).

Conclusion

In patients with chronic kidney disease, neither intravenous nor oral NAC is superior to placebo for preventing CIN.

The role of neutrophil-gelatinase-associated lipocalin in early diagnosis of contrast nephropathy

Neutrophil-gelatinase-associated lipocalin (NGAL) is a biomarker of acute kidney injury. The aim of this study was to define a cut-off for NGAL in the early diagnosis of contrast-induced nephropathy (CIN) in patients with normal kidney function. We enrolled 121 patients with normal serum creatinine who underwent coronary angiography. NGAL was measured in urine before the procedure and 12 and 24 h afterward. CIN was defined as a 0.3 mg/dl increase in serum creatinine within 48 h after the procedure. Seven of 121 patients had CIN (5.8%). The NGAL levels in the 12- and 24-h urine samples of these patients were 30 (5–45) and 20 (15–40) ng/ml, respectively, whereas those in patients without CIN were 15 (5–45) and 15 (10–51) ng/ml, respectively (P = 0.8). In patients with CIN, the sensitivity and specificity of NGAL with a cut-off of 22.5 ng/ml were 71.4% and 57.9% in 12-h urine samples, with the negative predictive values (NPV) and positive predictive values (PPV) of 97.1% and 9.4%, respectively. In conclusion, we suggest that urine NGAL with cut-off point of 22.5 ng/ml has acceptable sensitivity and specificity for early diagnosis of CIN in patients with normal serum creatinine, but regarding NPV and PPV the best performance of this value is to rule out the CIN in patients at risk who received contrast media.

The effect of magnesium sulphate on postoperative analgesia requirements in gynecological surgeries

Objective:

Recent studies have shown the positive effect of magnesium sulphate (MgSO4) on pain reduction and postoperative analgesic requirements in patients undergoing surgery. We assessed the effect of MgSO4 on intra-operative and postoperative analgesic requirements in patients undergoing lower abdominal gynecological laparotomy.

Materials and Methods:

This randomized clinical trial was conducted on 30 female patients at Rasool-e-Akram (referral and academic) hospital in Tehran from August 2012 to March 2013. The patients who were candidates for gynecologic surgeries (hysterectomy and/or myomectomy) were randomized into study (n=15) and control (n=15) groups. Same anesthetic technique was used in all patients. Besides induction of the anesthesia in the study group, we administered MgSO4 50 mg/kg/hr intravenously (IV) for analgesic purposes as a bolus dose and then 8 mg/kg IV as maintenance dose. Control group received the same anesthetic agents and the same amount of isotonic saline instead of MgSO4. Analgesic consumption was measured in both groups postoperatively within 24 hours. The visual analog scale (VAS) was used for the evaluation of postoperative pain in both groups.

Results:

There was a decrease in analgesic consumption and pain in the group receiving MgSO4, in comparison to control group. Pain severity assessment, 24 hours post operatively showed similar results in both groups. There was a statistically significant difference in prescribed dose of pethidine between study and control groups (p=<0.0001).

Conclusion:

Intra-operative MgSO4 is effective in postoperative pain control following lower abdominal laparotomy. Further studies with larger sample sizes and longer follow-up should be performed to obtain more information about safety and to determine whether doses of MgSO4 can provide postoperative analgesic benefits.

The influence of dexamethasone on postoperative nausea and vomiting in patients undergoing gynecologic laparoscopic surgeries: A randomised, controlled, double blind trial

OBJECTIVE

Dexamethasone, as a part of multimodal approach, can decrease nausea and vomiting following laparoscopy in high risk patients. We performed this study to find out whether the dexamethasone can improve postoperative nausea and vomiting (PONV) in patients undergoing gynecology laparoscopic surgeries.

MATERIALS AND METHODS

In this double-blind randomized clinical trial, 91 patients who underwent gynecologic laparoscopic surgery in Rasool Akram hospital in Tehran during 2011-2014 were enrolled. Fourty-four patients received 8 mg dexamethasone (study group) and 47 patients received 10 mg metochlopramide (control group) intravenously after intubation. Outcome parameters including age, weight, height, cause of hospitalization, drugs, Last Menstrual Period (LMP), Blood Pressure (BP), Heart Rate (HR), Respiratory Rate (RR) and oxygen saturation, Visual Analogue Scale (VAS) score, nausea and vomiting were entered to SPSS (v.16) and were analyzed.

RESULTS

Eighyt-eight American Society of Anesthesiology (ASA) class 1-2 patients between 25-39 years old were analyzed. There was no difference in vital signs during and post operation (BP, HR, RR and O₂ saturation) between these two groups (p value>0.05). There was no significant difference between VAS score at 4 and 24 hours after the operation (14% vs. 17.8% and 7% vs. 6.7%, respectively, p>0.05). Incidence of PONV in 4 hours was significantly lower in dexamethasone group (11.6% vs. 55.6% p<0.0001), while there was no significant difference in 24 hours (23.3% vs. 22.2%, p>0.05) and also need to anti-emetic drugs wasn't significantly lower in study group (p>0.05).

CONCLUSION

We conclude that dexamethasone can relieve PONV after gynecologic laparoscopic surgery.