Target-controlled dosing of remifentanil during cardiac surgery reduces postoperative hyperalgesia.

OBJECTIVE: One of the strategies to attenuate opioid-induced hyperalgesia (OIH) may be to decrease intraoperative doses of opioids by using target-controlled infusion (TCI). DESIGN: Double-blind and randomized study. SETTING: A single university hospital. PARTICIPANTS: Forty American Society of Anesthesiologists II to III patients scheduled for elective cardiac surgery. INTERVENTIONS: patients were randomized to 1 of the 2 groups: 1 group received an infusion of intraoperative remifentanil using TCI (target: 7 ng/mL), and the 2nd one was given an intraoperative continuous infusion (CI) (0.3 µg/kg/min). The anesthestic protocol and postoperative pain management were the same in both groups. The extent of mechanical dynamic hyperalgesia on the middle line perpendicular to the wound was considered the primary endpoint. The secondary endpoints were other results of dynamic and punctuate hyperalgesia until postoperative day 7, visual analog scale (VAS) and verbal rating scale (VRS) scores, and total morphine consumption until postoperative day 2. MEASUREMENTS AND MAIN RESULTS: Morphometric and demographic characteristics and duration of surgery were comparable in both groups. Intraoperative remifentanil consumption was greater in CI than in TCI group (5,329 [1,833] v 3,662 [1,160] µg, p = 0.003). During the first 44 hours, there were no differences in morphine consumption, VAS, and VRS. The extent of hyperalgesia was significantly lower on postoperative days 1, 2, and 4 in the TCI group than in the CI group on the 3 evaluated lines (p < 0.05). Punctuate hyperalgesia evaluating 3 different points was lower in the TCI than in the CI group from postoperative day 1 until postoperative day 7 (p < 0.05). CONCLUSIONS: The intraoperative decrease of opioid consumption when comparing the CI versus TCI mode of administration of remifentanil led to less OIH after cardiac surgery.

Evaluation of continuous veno-venous hemofiltration for the treatment of cardiogenic shock in conjunction with acute renal failure after cardiac surgery.

BACKGROUND: Cardiogenic dysfunction with acute renal failure (ARF) and diuretic drug resistance increases mortality after cardiac surgery with cardiopulmonary bypass (CPB) in adults. Until few years ago, intermittent renal replacement therapy (IRRT) was the only therapeutical strategy proposed to such patients. Few data are available in the literature regarding the use of continuous veno-venous haemofiltration (CVVH) in this clinical context. The aim of our observational study was to evaluate the impact of CVVH strategy on ARF in conjunction with cardiogenic shock after cardiac surgery and on its well-known associated poor outcome. METHODS: During the period 2005-2006, we prospectively collected data from our database as we controlled the renal replacement therapy using CVVH (n=73). We also retrospectively collected data from our computerised database on patients who were treated with IRRT (n=68, period 2002-2003). Among CVVH-treated patients, a multivariate analysis of the data aimed to identify risk factors associated with 30-day mortality. RESULTS: In patients who presented with ARF in conjunction with cardiogenic shock after cardiac surgery, 30-day mortality rate was 59% for the IRRT group and 42% for the CVVH group. Within the CVVH group, the logistic regression and multivariate analyses reported that some variables were associated with higher mortality risk: a score F concerning the urinary output criteria of the RIFLE (risk, injury, failure, loss, end-stage kidney disease) classification (for scores R or I: odds ratio (OR): 0.01, 95% confidence interval (95% CI): 0.02-0.59; p=0.01), plasma bilirubin (OR: 1.44, 95% CI: 1.12-1.84; p=0.04), total CVVH duration <50h over 72 h (>50h; OR: 0.009, 95% CI: 0.04-0.93; p=0.01), the need of catecholamine support (OR: 12.88, 95% CI: 1.95-84.96; p=0.01), tachycardia in the intensive care unit (ICU; OR: 1.64, 95% CI: 1.02-2.65; p=0.04), surgery duration (<300 min; OR: 0.11, 95% CI: 0.02-0.71; p=0.02) and combined cardiac surgery (OR: 7.00, 95% CI: 1.29-37.88; p=0.02). CONCLUSION: In patients with ARF in conjunction with cardiogenic shock after cardiac surgery, renal replacement therapeutic strategy based on long-lasting CVVH could improve patients' outcome. The identification of risk factors associated with a poor outcome would help to better manage such patients in the ICU. Low total duration of CVVH within the first 72 h was one criteria related to poor outcome. This suggests that CVVH must be initiated as soon as possible when ARF with diuretic resistance occurs in patients after cardiac surgery and continued as long as possible for the first 3 days.