2013 - November R3 Journal Review
Annane D et al. Effects of Fluid Resuscitation with Colloids or Crystalloids on Mortality in Critically Ill patients presenting with hypovolemic shock: the CRISTAL randomized trial. JAMA. 2013 Nov 6. 310(17) 1809-1817.
This was a multicenter (57 sites, 5 countries), randomized controlled prospective trial comparing resuscitation with colloids versus crystalloids in hypovolemic shock defined by 1) hypotension, 2) decreased cardiac output/low filling pressures and 3) signs of end organ hypoperfusion. Of the 6498 patients assessed for study criteria, a total of 2857 patients were enrolled from February 2003 through November 2012. 1414 were randomized to receive colloids and 1443 were randomized to receive crystalloids during their entire ICU resuscitation. Groups were well matched without significant difference including cause of hypovolemic shock (trauma, sepsis, other). The study was unblinded, and a variety of fluids were used in accordance with each institution’s practice. The goal was to compare therapeutic strategies (colloids versus crystalloids) rather than two molecular based formulas. The primary outcome was 28 day mortality. Secondary outcomes were 90 day mortality, as well as days without renal replacement therapy, mechanical ventilation, vasopressors and ICU and hospital length of stay.
Primary outcome: 25.4% (359/1414) of the colloid group died within 28 days, versus 27.0% of the crystalloid group (390/1443), with no significant difference (p=0.26).
Secondary outcomes: 90 day mortality: 30.7% (434/1414) of the colloid group died, versus 34.2% (493/1443) of the crystalloid group, which was statistically significant (p=0.03). There was no statistically significant difference in the need for renal replacement therapy (dialysis) or hospital length of stay. There was a significant difference in mechanical ventilation and vasopressor use at 7 and 28 days, with both favoring use of colloids.
This study concluded that there is no 28 day survival benefit to colloids when compared to crystalloids in ICU resuscitation for hypovolemic shock. There are some secondary outcomes that could benefit from more study: including an apparent survival benefit at 90 days, and potentially less need for life-support treatments (vasopressors, mechanical ventilation) without evidence of potential kidney injury noted in previous studies of colloids. However, there are limitations (unblinded study with high degree of variability) and the authors are understandably reluctant to make any strong recommendations. However, this is an interesting area for further exploration.
Agha BS et al. Pulmonary Embolism in the Pediatric Emergency Department. Pediatrics. 2013; 132:663-667.
This was a single, large, tertiary care pediatric center retrospective review from 2003 to 2011 aiming to identify the clinical course of and to describe pediatric patients ultimately diagnosed with PE. Investigators reviewed vital signs, signs and symptoms, medical history and risk factors, laboratory testing, and any imaging results in these patients diagnosed with PE. They excluded those patients with known PE or those in whom PE was a result of hospitalization/procedure/treatment. Twenty-five patients out of greater than one million total patient visits to this pediatric ED over the 9 years were ultimately included in the study. Eighty of the total 105 pediatric patients with PE during this time period were excluded because they had known PE prior, they were directly admitted (and did not pass through the ED), or had PE as a complication of hospitalization. 40% of patients diagnosed with PE had this diagnosis made in the ED and the remaining 60% were diagnosed while admitted with a mean time to diagnosis of these 60% of two days after admission. The most common risk factors for PE were BMI > 25, OCP use, and previously diagnosed DVT without PE. Indwelling catheters, post-operative, nephrotic syndrome, SLE, sickle cell, malignancy, and congenital heart disease were the other significant risk factors. The investigators also retrospectively applied Wells criteria and PERC rule to these 25 patients (with an adjusted HR max cutoff). None of the patients were considered ‘high risk’ using Wells criteria. 48% were ‘low risk.’ 52% were ‘moderate risk.’ When applying the PERC rule, 84% of patients were correctly identified as needing further workup for PE with tachycardia being the most common reason (and source of PERC rule failure).
PE in the pediatric population is very rare. As such, it is difficult to diagnose often times with large delays in diagnosis. This retrospective review aimed at identifying the characteristics of pediatric patients with PE to promote earlier diagnosis. It is limited in that they excluded 80/105 patients with PE from their study because of direct admission or prior history of known PE. Interestingly, the PERC rule had a 16% false negative rate when applied retrospectively to this population. Overall, PE should remain on our differential in appropriate cases and strict adherence of Wells criteria or PERC rule should be avoided in this population.
Traub SJ et al. N-Acetylcysteine plus intravenous fluids versus intravenous fluids alone to prevent contrast-induced nephropathy in emergency computed tomography. Ann Emerg Med. 2013 Nov; 62(5): 511-520.
This article is a randomized, double blind, 2-center, placebo-controlled study. Patients who were undergoing chest, abdominal or pelvic CT scan with IV contrast were enrolled. Patients were older than 18, had one risk factor for developing contrast induced nephropathy; exclusion criteria were: ESRD, pregnancy, NAC allergy, or clinical instability. Patients were divided into two groups: Intervention group received NAC 3g in 500mL NS and 200mg/h (67mL/h) for up to 24h. Placebo group received 500mL NS bolus and then 67 mL/h NS for up to 24 hours. Primary outcome was contrast-induced nephropathy measured by an increase in creatinine by 25% from baseline – measured 48-72 hours after the CT. The study was terminated early for futility. There was NO significant difference between the NAC and NS alone group. After reviewing 357 of the 399 enrolled patients, it was shown that those patients that received <1L NS in the ED prior to the CT scan had a higher rate of contrast induced nephropathy compared to those patients that received >1L NS (12.9% vs 3.3% - no p-value given). Conclusion: in patients with small risk of CIN – no benefit to prophylaxis with NAC – simple fluid hydration is effective.