2013 - October R3 Journal Review
Myburgh JA et al. Resuscitation Fluids. N Engl J Med. 2013 Sep 26; 369(13): 1243-1251
This article is a review article of 50 studies reviewing the safety, efficacy, and utility of different IV fluid for resuscitation in the acutely ill patient. These studies were performed in the ED and ICU setting. Authors used a definition of “ideal resuscitation fluid” as one that provides a predictable and sustained increase in intravascular volume; has a composition as close as possible to that of extracellular fluid; is metabolized and completely excreted without tissue accumulation; does not produce adverse metabolic or systemic effects; and is cost effective.
Authors evaluated the different options:
1) Colloid (albumin)
- expensive; safe; may be useful in early sepsis (one study-has not been substantiated; many studies show no difference than with saline); increased mortality in TBI; albumin theoretically keeps fluid in the intravascular space because the molecule is too large to go to the extravascular space (but this is in healthy tissues)
2) Hydroxyethyl starch (HES)
- idea that it is a cheaper, synthetic version of albumin; has shown increased rates of renal-replacement therapy and adverse events in ICU patients; no evidence to use over any other colloid solutions. No evidence that this is better than Ringer’s or NS.
- the standard (especially in the US); associated with the development of metabolic acidosis and AKI, but overall very safe.
- unknown safety-not ready for mainstream.
All have been shown to cause interstitial edema. In conclusion, no ideal resuscitative fluid exists. Each patient’s fluid requirements will change as their condition and status change. Article recommends reassessing patient as condition changes. Fluids should be considered the same as any other IV drug, need to maximize efficacy and minimize toxicity. For us as EPs, no new data to suggest changing from using NS as the initial fluid resuscitation fluid in the ED, but to reassess as the patient’s condition changes (especially if they are boarding in the ED for an extended period).
Cullen L et al. Validation of high-sensitivity troponin I in a 2-hour diagnostic strategy to assess 30-day outcomes in emergency department patients with possible acute coronary syndrome JACC 2013 Oct, 1;62(14)1242-9 This multicenter prospective cohort study provided internal and external validation of a 2 hour accelerated diagnostic protocol (ADP) for patients with low risk chest pain. In the internal validation, patients were recruited with more than 5 min of symptoms consistent with AHA case definitions of possible cardiac symptoms from a hospital in New Zealand and a hospital in Australia. The external validation cohort was recruited from hospitals in Switzerland, Spain and Italy including patients with symptoms suggestive of acute MI with onset or peak symptoms within 12 hours of presentation. Exclusion criteria included: age<18 years, inability or unwillingness to consent, patients transferred from another hospital, patients that could not be followed up and patients on dialysis. The primary outcome measure was a composite end point in 30 days of death, cardiac arrest, AMI, emergency revascularization, cardiogenic shock, ventricular arrhythmia requiring intervention and high degree AV block requiring intervention. Patients defined as low risk by TIMI score of 0-1, non-ischemic ECG and negative 0 and 2 hours ultrasensitive troponins (defined as <99th percentile) were followed for 30 days to evaluate for safety of this protocol. 3,592 patients were recruited 1,048 were excluded for multiple reasons (incomplete TIMI score, no serial blood samples, no ECG available and chest pain of unknown origin with elevated troponin). 1,029 patients met low risk criteria by the ADP. Three patients in this cohort had an adverse event as defined in the primary outcome. Patient 1 had 2 negative ultrasensitive troponins but reference troponins increased and he underwent angiogram which showed no lesions. Patient 2 had 2 negative ultrasensitive troponins, underwent angiography and was found to have a 30% LAD lesion, no intervention was performed. Patient 3 had 2 negative ultrasensitive troponins, underwent and exercise treadmill test which was negative but was diagnosed with an NSTEMI. No intervention was performed. The conclusion of this study is that outpatient follow up is safe in patients with a TIMI score of 0-1 and negative 0 and 2 hour troponins. It should be noted that this study did not include change in troponin as criteria for failing the ADP if both troponins were negative. The study population was also primarily Caucasian which may limit generalizability (ethnicity demographic statistics not published).
Holmes, et al. Identifying Children at Very Low Risk of Clinically Important Blunt Abdominal Injuries, Ann Emerg Med. 2013;62:107-116.
Intra-abdominal injury is an important and leading cause of morbidity in children. CT scans can often identify these injuries, but CTs have radiation exposure as a critical drawback. The authors attempted to derive a clinical prediction rule to find children at low risk of clinically important intra-abdominal injuries (IAI) requiring acute intervention, thus potentially avoiding CT usage in this population.
Using the PECARN network the authors enrolled 12,044 children (ages 0-18, median age 11.1 years) who had blunt torso trauma. Notably excluded were patients presenting after 24 hours from injury, with preexisting neurological disorders, known pregnancy, and transfers from other facilities with prior imaging. Of the 12,044 enrolled patients, 6.3% had IAI, and only 1.7% (203 patients) required acute intervention. The derived prediction rule includes seven variables, in order of importance:
1. Evidence of abdominal wall trauma or seat belt sign
2. GCS score less than 14
3. Abdominal tenderness
4. Evidence of thoracic wall trauma
5. Complaints of abdominal pain
6. Decreased breath sounds
This rule, when all negative, place a patent at a very low risk, 0.1%, for IAI requiring acute intervention. The rules have a negative predictive value of 99.9%, negative likelihood ratio of 0.07, a sensitivity of 97.0% (95% CI 93.7%-98%), and a specificity of 42.5% (95% CI 41.6%-43.5%) for IAI requiring acute intervention. Adding FAST and lab work as criteria to these seven variables, which was not included here, would further improve the above results. The authors conclude that had these rules been applied to these 12,044 patients, 1,254 CTs could have been avoided. Importantly, the authors point out that the converse of this rules does not hold true, as it only has a 92.5% sensitivity for finding any IAI (intervention or not). It is important to distinguish that if a patient is positive for any of the above variables, they don't automatically require CT, as this was derived to identify low risk patients who possibly don't need CT.
This study does a great job of deriving rules to assist finding those patients that may have been involved a traumatic event who don't need CT scans and can be worked-up without CTs. Like all rule derivations, it requires additional external validation (which seems to always show decreased test performance compared to the derivation) before it can be used clinically. That said, you can feel pretty confident in your decision to not CT pediatric patients that meet the above criteria (especially if they have a negative FAST) when it correlates with your sound clinical judgment.