2012 January R3 Journal Review
Reades R, Studnek J, Vandeventer S, Garrett J. Intraosseous Versus Intravenous Vascular Access During Out-of-Hospital Cardiac Arrest. Ann Emerg Med. 2011 Dec; 58(6): 509-516.
Although intraosseous needle insertion is commonly used in the pediatric population, it has become more frequently used in the adult population as well, especially in the out-of-hospital setting when immediate vascular access is required such as in cardiac arrest.
The objective of this study was to assess frequency of first-attempt success between the humeral IO, tibial IO, and peripheral IV routes during out-of-hospital cardiac arrest.
This study was a prospective, nonblinded, triple-arm, randomized controlled trial, conducted by a municipal all-advanced life support EMS agency. The study enrolled patients >18 yrs old experiencing an out-of-hospital (medical) cardiac arrest from May 2010 to October 2010. Exclusion criteria included traumatic arrest, peripheral IV access prior to arrest, those with successful resuscitation before attempted vascular access, those with DNR orders, or those with any contraindication for the use of any of the vascular access methods
Patients were randomized to one of the 3 locations – proximal tibia IO, proximal humeral IO, or peripheral IV. Randomized note cards were distributed to paramedics at the beginning of each shift, indicating which vascular access site was to be used initially if they responded to an out-of-hospital cardiac arrest during their shift. The primary outcome measure was first-attempt success at the assigned method of vascular access, defined as initial success (secure placement) and overall success (needle dislodgement and/or inability to administer medications/fluid). Secondary outcomes included total number of attempts required, time to successful vascular access, time to first ACLS meds, and total volume of fluid infused during resuscitation.
Results showed that first-attempt success at vascular access was significantly higher (P<0.001) with tibial IO access (91%; 95% CI 83% to 98%) compared with that of humeral IO access (51%; 95% CI 37% to 65%) or peripheral IV access (43; 95% CI 31% to 55%). Humeral IO devices were more likely to dislodge. In regards to secondary outcomes, time to initial success was significantly shorter for the tibial IO route (4.6 minutes; IQR 3.6 to 6.2 min) compared with the humeral IO route (7.0 minutes; IQR 3.9 to 10.0 min). There was, however, a larger amount of fluid infused with the peripheral IV (800mL; IQR 500 to 1,000 mL).
Limitations of this study include that the study only tested one IO device and insertion process, the study was not designed to test safety, end outcome or survival to hospital discharge. Also, the various time measurements were documented on a time log with no universal clock used. Variables such as morbidity and mortality were not available for analysis. They were unable to correlate survival rates or return of spontaneous circulation to either vascular access method. Also, the average weight of the patients in the humeral IO group was greater than the other two groups and may have been associated with more difficult vascular access.
In summary, results demonstrated that the tibial IO route was the most effective method of gaining vascular access during out-of-hospital cardiac arrest with decreased time to initial needle placement and less frequent dislodgement than humeral IO. Proximal humeral IO placement proved to be suboptimal with success rate of 50% and dislodgement of 20%. This study demonstrated that tibial IO vascular access placement has a higher success rate than peripheral IV on first attempt and are quicker than peripheral IV insertions. However, twice the amount of fluid was infused through peripheral IV catheters. To be noted, the cost related to IO access is much greater than IV access and there is yet to be studies done comparing cost-effectiveness. Results from this study may help EMS directors with protocols regarding vascular access in out-of-hospital cardiac arrest. It also should remind EM physicians that IO vascular access is a quick and effective means to achieve vascular access in our critically ill or cardiac arrest patients in the Emergency Department, as it is in the out-of-hospital setting.
Payen, JF et al. Corticosteroid after etomidate in critically ill patients: A randomized controlled trial. Crit Care Med. 2012; 40(1):29-35.
There is much debate over the use of etomidate for sedation for RSI of critically ill patients. Previous studies have suggested that single-dose etomidate blocks cortisol synthesis, resulting in a primary adrenal insufficiency that lasts up to 48 hours. Hydrocortisone has been used for treatment of those with adrenal insufficiency who do not respond to fluids and/or vasopressors. The authors' goal was to investigate the use of hydrocortisone administration in patients given a single dose of etomidate, and to determine its effectiveness at decreasing the proportion of vasopressor-dependent patients.
This was a prospective, single center, randomized, controlled, double-blind trial. They included any adult patient that received etomidate to facilitate sedation for RSI. Exclusion criteria included septic shock requiring steroids, chronic adrenal insufficiency, pituitary disorder, etomidate administration >24 hours after admission to ICU, and several others. Patients were randomized to receive either hydrocortisone (HC) (200 mg in 50 mL saline solution) or normal saline (control) (50 mL). Solutions were infused over 42 hours starting at hour 6 (H6). A corticotrophin test was performed at H5, prior to administration of the treatment. Primary outcome was the requirement of vasopressors at H6, H12, H24, H48 for patients with a SOFA score of 3 or 4. Secondary outcomes include course of norepinephrine dose, max serum glucose, number of patients treated with insulin, max SOFA score, 28-day all-cause mortality, duration of mechanical ventilation, length of ICU stay, # of ICU days with norepinephrine support.
A total of 103 patients were potentially eligible, and 97 were randomized: 48 in the HC group, 49 in the control group. Hormonal assays were performed in 90 patients. There were 41/45 (91%) who met criteria for adrenal insufficiency in the HC group and 38/45 (84%) in the control group. The proportion of patients with SOFA score 3 or 4 declined comparably between HC and control groups (p<.01). MAPs were also comparable between the two groups (p<.05). There was no difference between the two groups for any of the secondary outcomes either (p<.05).
Etomidate was not used in all patients, and that decision was left to the intubating provider. Steroids were not started until H6. There was no benefit from hydrocortisone to overcome etomidate-related adrenal insufficiency. "Single-dose etomidate could be considered in critically ill patients undergoing RSI…without major concerns about its drug-induced hormonal derangement." This article tells us that, yes, etomidate does block cortisol synthesis, but it is not clinically significant and doesn't affect important end points like mortality, LOS, days on the vent.