14 Sep 12
By K Raghunathan, W McGee, T Higgins
Curr Opin Crit Care 2012;18:350-357
This review discusses the importance of intravenous fluid dose and composition in surgical ICU patients. On the basis of updated physiologic postulates, we suggest guidelines for the use of crystalloids and colloids. Goal-directed fluid therapy is advocated as a means for avoiding both hypovolemia and hypervolemia.
Integrity of the endothelial surface layer (ESL) and ‘volume context’ are key determinants of fluid disposition. During critical illness the ESL is compromised. Optimal resuscitation may be guided by functional measures of fluid responsiveness with some caveats. The best approach may be to use physiologically balanced crystalloids for hypovolemic resuscitation and colloids for euvolemic hemodynamic augmentation.
The routine replacement of unmeasured presumed fluid deficits is not appropriate. In critically ill patients, resuscitation with intravenous fluids should produce a demonstrable enhancement of perfusion. Individualized goal-directed therapy using functional hemodynamic parameters can optimize resuscitation and ‘deresuscitation’.
12 Sep 12
By R Thiele, J Huffmyer, J Raphael, Jacob
Curr Opin Crit Care 2012;18:358-365
To identify the recent literature supporting the ability of anesthesiologists to impact morbidity and mortality outside of the immediate intraoperative period.
Hemodynamic management designed to optimize cardiac output and stroke volume can significantly lower the risk of perioperative morbidity, and, in some cases, mortality. The implications of the POISE trial, which upended the previously accumulating data in support of indiscriminate perioperative β-blockade by demonstrating worsened outcomes, were supported by high-quality, propensity-matched, prospectively collected data. Data supporting the safety of colloid use has been threatened by the retraction of 88 publications of a single author, as well as prospective, nonrandomized data, suggesting increased renal morbidity in critically ill patients receiving synthetic colloids. Large datasets continue to suggest an association between red blood cell transfusion and mortality. Analysis of the operating room strongly implicates anesthesia providers as a potential mechanism for bacterial contamination.
Anesthesiologists should consider implication of goal-directed therapy in high-risk surgical patients, adhere to the American College of Cardiology/American Heart Association guidelines with regard to perioperative β-blockade, critically assess the data to support their choice of synthetic colloids over crystalloids, explore all possible strategies for avoiding perioperative transfusion, and be cognizant of their potential contribution to perioperative infectious morbidity.
11 Sep 12
By K Choong, S Arora S, J Cheng
The objective of this randomized controlled trial was to evaluate the risk of hyponatremia following administration of a isotonic (0.9% saline) compared to a hypotonic (0.45% saline) parenteral maintenance solution (PMS) for 48 hours to postoperative pediatric patients.
Surgical patients 6 months to 16 years of age with an expected postoperative stay of >24 hours were eligible. Patients with an uncorrected baseline plasma sodium level abnormality, hemodynamic instability, chronic diuretic use, previous enrollment, and those for whom either hypotonic PMS or isotonic PMS was considered contraindicated or necessary, were excluded. A fully blinded randomized controlled trial was performed. The primary outcome was acute hyponatremia. Secondary outcomes included severe hyponatremia, hypernatremia, adverse events attributable to acute plasma sodium level changes, and antidiuretic hormone levels.
A total of 258 patients were enrolled and assigned randomly to receive hypotonic PMS (N = 130) or isotonic PMS (N = 128). Baseline characteristics were similar for the 2 groups. Hypotonic PMS significantly increased the risk of hyponatremia, compared with isotonic PMS (40.8% vs 22.7%; relative risk: 1.82 [95% confidence interval: 1.21–2.74]; P = .004). Admission to the pediatric critical care unit was not an independent risk factor for the development of hyponatremia. Isotonic PMS did not increase the risk of hypernatremia (relative risk: 1.30 [95% confidence interval: 0.30–5.59]; P = .722). Antidiuretic hormone levels and adverse events were not significantly different between the groups.
Isotonic PMS is significantly safer than hypotonic PMS in protecting against acute postoperative hyponatremia in children.
23 Aug 12
By A Perner, N Haase, A Guttormsen, J Tenhunen, G Klemenzson, A Åneman, K Madsen, et al for the 6S Trial Group and the Scandinavian Critical Care Trials Group
N Engl J Med 2012; 367:124-134
Hydroxyethyl starch (HES) is widely used for fluid resuscitation in intensive care units (ICUs), but its safety and efficacy have not been established in patients with severe sepsis.
In this multicenter, parallel-group, blinded trial, we randomly assigned patients with severe sepsis to fluid resuscitation in the ICU with either 6% HES 130/0.42 (Tetraspan) or Ringer’s acetate at a dose of up to 33 ml per kilogram of ideal body weight per day. The primary outcome measure was either death or end-stage kidney failure (dependence on dialysis) at 90 days after randomization.
Of the 804 patients who underwent randomization, 798 were included in the modified intention-to-treat population. The two intervention groups had similar baseline characteristics. At 90 days after randomization, 201 of 398 patients (51%) assigned to HES 130/0.42 had died, as compared with 172 of 400 patients (43%) assigned to Ringer’s acetate (relative risk, 1.17; 95% confidence interval [CI], 1.01 to 1.36; P=0.03); 1 patient in each group had end-stage kidney failure. In the 90-day period, 87 patients (22%) assigned to HES 130/0.42 were treated with renal-replacement therapy versus 65 patients (16%) assigned to Ringer’s acetate (relative risk, 1.35; 95% CI, 1.01 to 1.80; P=0.04), and 38 patients (10%) and 25 patients (6%), respectively, had severe bleeding (relative risk, 1.52; 95% CI, 0.94 to 2.48; P=0.09). The results were supported by multivariate analyses, with adjustment for known risk factors for death or acute kidney injury at baseline.
Patients with severe sepsis assigned to fluid resuscitation with HES 130/0.42 had an increased risk of death at day 90 and were more likely to require renal-replacement therapy, as compared with those receiving Ringer’s acetate.