Colloids and Crystalloids Are Largely Equivalent for Fluid Resuscitation of Hypovolemic Shock
Annane D, Siami S, Jaber S, et al, CRISTAL Investigators. Effects of fluid resuscitation with colloids vs crystalloids on mortality in critically ill patients presenting with hypovolemic shock. JAMA. 2013; 310:1809-17. PubMed
Background: Both colloids and crystalloids may have theoretical benefits in the management of hypovolemic shock, but early data from small studies suggested that they may not be equivalent in practice (7). The CRISTAL (Colloids Versus Crystalloids for the Resuscitation of the Critically Ill) study is the latest entry in recent years to address this area of clinical uncertainty.
Findings: 2857 adults in hypovolemic shock were studied. Patients were randomly assigned to receive any colloid versus any crystalloid for initial acute resuscitation of hypovolemic shock in the ICU. Those treated with colloids received significantly less fluids than those treated with crystalloids (median volume administered in first 7 days, 2000 vs. 3000 mL, respectively). There was no difference in 28-day mortality (25.4% in the colloid group vs. 27.0% in the crystalloid group), although the colloid group had more vasopressor-free and ventilator-free days.
Cautions: Clinicians were not blinded to the use of study fluids, leaving the study susceptible to potential bias. Specific colloid and crystalloid agents were not compared, allowing comparison only of 2 large classes, and possible adverse effects with specific agents may have been missed.
Implications: This study suggests that, in general, colloids are noninferior to crystalloids for the acute resuscitation of hypovolemic shock. Nonetheless, an individualized approach to each patient is still warranted, because other studies have raised agent-specific concerns, such as the potential for kidney injury with use of hydroxyethyl starch (8), or have suggested situation-specific caution, such as use of albumin in the setting of traumatic brain injury (9). Given cost differences, crystalloids may still be preferable to colloids for initial resuscitation of these patients.
Addition of Steroids and Vasopressin Improves Neurologically Favorable Survival After In-Hospital Cardiac Arrest
Mentzelopoulos SD, Malachias S, Chamos C, et al. Vasopressin, steroids, and epinephrine and neurologically favorable survival after in-hospital cardiac arrest: a randomized clinical trial. JAMA. 2013; 310:270-9. PubMed
Background: The survival rate after in-hospital sudden cardiac arrest requiring vasopressors is very poor. These investigators did a previous study in which the combination of vasopressin, epinephrine, and methylprednisolone given during in-hospital cardiac arrest was associated with increased survival to hospital discharge (10). The current study was conducted to extend those findings and assess survival with favorable neurologic function.
Findings: 364 adult patients with sudden in-hospital cardiac arrest were consecutively enrolled and randomly assigned to receive vasopressin and steroid (methylprednisolone) with epinephrine (VSE group) or placebo with epinephrine. The VSE recipients who survived resuscitation with postresuscitation shock also received stress-dose hydrocortisone. The VSE group had significantly increased return of spontaneous circulation and increased survival to hospital discharge with favorable neurologic recovery (survival rate, 14% vs. 5.1% in the placebo group), as well as more days free of neurologic or renal failure.
Cautions: The control group had a greater number of cardiac arrests due to respiratory and metabolic causes, which are known to have worse outcomes than arrest due to cardiac causes. Not all patients with ventricular tachycardia or fibrillation arrest received therapeutic hypothermia; more uniform application of this therapy may have altered the benefits seen with VSE therapy.
Implications: Although the results of this well-designed study demonstrate that the addition of vasopressin and steroids strikingly improved survival in patients who develop in-hospital cardiac arrest, this finding will need to be validated in different settings before broad application. Until then, systematic consideration of proven therapies, such as therapeutic hypothermia, should be pursued.
Restrictive Transfusion Strategy Reduced Mortality in Patients With Acute Upper Gastrointestinal Bleeding
Villanueva C, Colomo A, Bosch A, et al. Transfusion strategies for acute upper gastrointestinal bleeding. N Engl J Med. 2013; 368:11-21. PubMed
Background: Meta-analyses of trials comparing restrictive red blood cell transfusion strategies with liberal transfusion strategies have shown no significant differences in outcomes (11), but nearly all trials have excluded patients with acute gastrointestinal bleeding. This study was performed to address this gap in evidence.
Findings: 921 adult patients with severe acute upper gastrointestinal bleeding and high risk for rebleeding were recruited from a single hospital in Spain and randomly assigned to receive a restrictive transfusion strategy (at a hemoglobin level <7 g/dL) or a liberal strategy (at a hemoglobin level <9 g/dL). Patients with massive exsanguination or active cardiovascular or cerebrovascular disease were excluded. The restrictive transfusion group had a 45% reduction in all-cause mortality (5.2% vs. 9.2%, respectively), fewer episodes of recurrent bleeding (10% vs. 16%), and fewer in-hospital complications (40% vs. 48%).
Cautions: The transfusion strategy was broken at the discretion of clinicians when such circumstances as massive bleeding or surgical intervention occurred; this ensued more often in the restrictive strategy group than the liberal strategy group (8% vs. 3%, respectively) and may have influenced results. Exclusion criteria were extensive and limit the generalizability of this study; of note, patients with lower gastrointestinal bleeding were excluded.
Implications: Most patients with upper gastrointestinal bleeding and high risk for rebleeding should be managed with a restrictive red blood cell transfusion strategy, with transfusion occurring when the hemoglobin level falls to less than 7 g/dL. Modification of this threshold should be considered in patients with massive exsanguination and those with active or recent cardiovascular or cerebrovascular disease.
Universal Decolonization Prevents More ICU Infections Than MRSA Screening and Isolation
Huang SS, Septimus El, Kleinman K, et al, CDC Prevention Epicenters Program; AHRQ DECIDE Network and Healthcare-Associated Infections Program. Targeted versus universal decolonization to prevent ICU infection. N Engl J Med. 2013; 368:2255-65. PubMed
Background: Health care–associated infections caused by MRSA are a significant source of morbidity and mortality, particularly in the ICU. The current strategy of polymerase chain reaction assay–based detection and contact isolation is resource-intensive and may have adverse effects on patient care.
Findings: The study was conducted in 78 U.S. community-based adult ICUs with preexisting infection prevention procedures. The investigators followed 48 390 patients during a baseline period and compared them with 74 256 patients during the intervention period. During the intervention period, participating ICUs were randomly assigned to 1 of 3 groups: standard MRSA screening plus contact isolation, MRSA screening plus targeted decolonization of MRSA-colonized patients with intranasal mupirocin and chlorhexidine bathing, or empirical mupirocin plus chlorhexidine decolonization of all patients admitted to the ICU. Universal decolonization was associated with a 37% reduction in MRSA-positive blood cultures and a 44% reduction in bloodstream infections by any organism.
Cautions: The differential effect of intranasal mupirocin versus chlorhexidine bathing was not examined. Monitoring for resistance to mupirocin and chlorhexidine was not performed.
Implications: Universal decolonization with chlorhexidine bathing and adjunctive therapy may be more effective at reducing nosocomial ICU infection than MRSA-specific screening and isolation policies. More generally, these findings suggest that broadly applicable population-based interventions, such as hand hygiene or bundled care, offer more promise for infection control than individualized, disease-specific strategies, such as pathogen-specific screening and isolation.
Prone Positioning Improves Survival Among Selected Patients With Severe ARDS
Guérin C, Reignier J, Richard JC, et al, PROSEVA Study Group. Prone positioning in severe acute respiratory distress syndrome. N Engl J Med. 2013; 368:2159-68. PubMed
Background: Management of severe ARDS can be challenging; in many cases, lung injury is heterogeneous, such that volume and pressure applied by the mechanical ventilator may be unequally distributed throughout the lung. This study was performed to assess the effect of early use of prone positioning, which has been shown to improve ventilation–perfusion matching (12).
Findings: In a prospective trial in 27 European ICUs with experience in prone positioning, 576 patients with severe ARDS and no contraindications were randomly assigned (out of 1434 patients who were screened) to prone positioning instituted within 36 hours of ARDS recognition versus standard supine care. Prone patients spent 73% of available time in the prone position, with an average of 17 hours per prone session and a mean of 4 sessions per patient.
Patients in the prone position had higher oxygenation and better lung mechanics by day 3 and, compared with the control group, had significantly lower 28-day mortality (16% vs. 32%) and 90-day mortality (24% vs. 41%). There was no significant increase in the number of adverse events from prone positioning.
Cautions: Patients were highly selected; less than 15% of all patients with ARDS were randomly assigned. All staff performing prone positioning had more than 5 years’ experience with these procedures. Patients in the study received a lower positive end-expiratory pressure strategy, even though a recent meta-analysis suggests that higher positive end-expiratory pressure strategies may be better in patients with moderate to severe ARDS (13).
Implications: Early consideration should be given to prone positioning during ventilation for patients with moderate to severe ARDS and persistent hypoxemia despite ventilator optimization. Application of prone positioning requires staff training and adequate personnel to perform the maneuver, as well as appropriate monitoring for complications of this position.
