Critical Care Reviews Newsletter
February 26th 2012
Welcome
Hello
Welcome to the 12th Critical Care Reviews Newsletter. Every week over a hundred clinical and scientific journals are reviewed and the most important and interesting research publications in critical care are highlighted. These studies are added to the Journal Watch section of the website on a daily basis, as publication occurs. A link to either the full text or abstract, depending on the publisher's degree of open access, is attached. Higher level evidence is focused on, unless the publication is of special interest.
Emergency Medicine Australasia
CT PanScan in Trauma
To examine the utility of a panscan in blunt trauma, Asha and colleagues, in an before (n=656) and after (n=624) the introduction of a panscan protocol, compared the proportion of patients exposed to a radiation dose in excess of 20 mSv, and the incidence of missed injuries. The proportion of patients exposed to a radiation dose >20 mSv increased by 8% (95% CI: 4–12), which equated to one extra person being exposed to >20 mSv for every 13 patients treated after the introduction of the protocol. The odds of receiving a radiation dose >20 mSv after the introduction of the protocol compared with the odds before were increased across all subgroups. There were six missed injuries before and four after.
Resuscitation
Cardiac Arrest
In a randomised, double-blind, multi-centre, parallel-design clinical trial in four adult hospitals, Hock et al compared an initial dose of either adrenaline (1 mg) or vasopressin (40 IU), followed by current standard cardiac arrest management, in 727 patients in cardiac arrest in the Emergency Department. Both groups had comparable baselines. Eight participants (2.3%) from adrenaline and 11 (2.9%) from vasopressin group survived to hospital discharge with no significant difference between groups (p=0.27, RR=1.72, 95% CI=0.65 to 4.51). Sub-group analysis suggested improved outcomes for vasopressin in participants with prolonged arrest times.
Clinical Infectious Diseases
Vancomycin for MRSA
In a systematic review and meta analysis, van Hall and colleagues assessed the clinical significance of vancomycin minimum inhibitory concentration in 22 trials of MRSA infection. Vancomycin MIC was associated with mortality for MRSA infection irrespective of the source of infection or MIC methodology (OR 1.64; 95% CI: 1.14–2.37; P < 0.01). This mortality association was predominantly due to bloodstream infections (BSIs; OR, 1.58; 95% CI, 1.06–2.37; P = 0.03) and isolates with a vancomycin MIC of 2 μg/mL by Etest (OR, 1.72; 95% CI, 1.34–2.21; P < 0.01). Vancomycin MIC was associated with treatment failure irrespective of source of infection or MIC methodology (OR, 2.69; 95% CI, 1.60–4.51; P < 0.01).
European Journal of Heart Failure
Procalcitonin in Dyspnoea
In a prospective, international, observational study, Maisel and colleagues investigated the utility of procalcitonin (PCT), with or without clinical parameters, in the management of dyspnoea in the emergency department (BACH study). A model using PCT was more accurate (AUC 72.3%) than any other individual clinical variable for the diagnosis of pneumonia in all patients, in those with obstructive lung disease, and in those with acute heart failure (AHF). Combining physician estimates of the probability of pneumonia with PCT values increased the accuracy to >86% for the diagnosis of pneumonia in all patients. Patients with a diagnosis of AHF and an elevated PCT concentration (>0.21 ng/mL) had a worse outcome if not treated with antibiotics (P = 0.046), while patients with low PCT values (<0.05 ng/mL) had a better outcome if they did not receive antibiotic therapy (P = 0.049).
Anesthesia & Analgesia
Unplanned Extubation
In a systematic review spanning 62 years and 50 studies, da Silva and colleagues examined the effects of unplanned extubations in ICU. Unplanned extubations occur at a rate of 0.1 to 3.6 events per 100 intubation days. Risk factors associated with unplanned extubations included male gender, APACHE score ≥17, chronic obstructive pulmonary disease, restlessness/agitation, lower sedation level, higher consciousness level, and use of physical restraints (OR 3.1). Reintubation rates ranged from 1.8% to 88%.
Traumatic Brain Injury
In an observational study of 66 patients admitted to ICU with mild-to-moderate traumatic brain injury, Degos and colleagues assessed the association of estimated specific gravity (eST) on CT with 6 month outcomes. Univariate and stepwise multivariate analyses showed an independent association between eSG and 6-month poor outcome (P = 0.001). ROC-AUC of eSG for the prediction of 6-month outcomes was 0.87 (confidence interval: 0.77–0.96). Admission eSG values were correlated with 14-day mortality (P = 0.004), length of mechanical ventilation (P = 0.01), length of ICU stay (P = 0.045), and intracranial pressure monitoring (P < 0.001).
American Journal of Respiratory and Critical Care Medicine
Fever Supression in Septic Shock
In a multicenter randomized controlled trial, Schortgen et al compared fever supression with external cooling (n=101) to achieve normothermia (36.5-37°C) for 48 hours with no external cooling (n=99) in critically ill febrile patients with septic shock. Body temperature was significantly lower in the cooling group after 2 hours of treatment (36.8±0.7 vs. 38.4±1.1°C, P<0.01). A 50% vasopressor dose decrease was more common with external cooling after 12 hours of treatment (54% vs. 20%; 95% CI: -46 to -21; P<0.001) but not at 48 hours. Shock reversal during the ICU stay was significantly more common with cooling (86% vs. 73%; 95%CI: 2 to 25; P=0.021). Day-14 mortality was significantly lower in the cooling group (19% vs. 34%; 95%CI: -28 to -4; P=0.013).
Resuscitation
Ultrasound for Tracheal Tube Placement
Sim and colleagues performed a prospective, single centre, observational study to determine the accuracy and timeliness of ultrasound to confirm emergency endotracheal tube (ETT) placement in 115 patients. ETT position was confirmed with a transducer placed on the chest bilaterally at the mid-axillary line, to identify the lung sliding over the lungs bilaterally during ventilation. The accuracy of ultrasound to confirm proper endotracheal intubation was 88.7% (95% CI: 81.6–93.3%). The positive predictive value was 94.7% (95% CI: 87.1–97.9%) in non-cardiac-arrest patients and 100% (95% CI: 87.1–100.0%) in the cardiac-arrest patients. The median operating time of ultrasound was 88
s (interquartile range [IQR]: 55.0, 193.0), and of chest radiography was 1349s (IQR: 879.0, 2221.0) post intubation.
Out-of-Hospital Cardiac Arrest
Brei and colleagues conducted a pre-hospital randomized study with the Emergency Medical Service of Bonn, Germany, comparing hypertonic saline {2mlkg−1 7.2% NaCl with 6% hydroxyethyl starch 200,000/0.5 (HES)} with HES in 203 out-of-hospital cardiac arrest patients. Hypertonic saline was associated with a brief rise in serum Na from 162±36mmoll−1 at 10min after infusion to near normal (144±6mmoll−1) at hospital admission. Survival to hospital admission and hospital discharge was similar in both groups (50/100 7.2% NaCl vs. 49/103 HES for hospital admission, 23/100 HHS vs. 22/103 HES for hospital discharge). There was a small improvement in neurological outcome at discharge in survivors who received 7.2% NaCl (cerebral performance category 1 or 2; 13/100 7.2% NaCl vs. 5/100 HES, p<0.05, odds-ratio 2.9, 95% CI 1.004–8.5).
Archives of Surgery
Blunt Abdominal Surgery
Over a 14 year period, Berg et al examined the patterns of injury in 1661 patients with blunt thoracoabdominal injury in a level 1 trauma centre in the USA. Intra-abdominal solid organ injury occurred in 59.7% and hollow viscus injury in 6.0%. Blunt cardiac trauma occurred in 6.3%; major thoracic vessel injury, in 4.6%; and diaphragmatic trauma, in 6.0%. 474 (28.5%) required laparotomy, 31 (1.9%) required thoracotomy (excluding resuscitative thoracotomy), and 1146 (69.0%) did not require an operation. The majority of solid organ injuries were managed nonoperatively (liver, 83.9%; spleen, 68.3%; and kidney, 91.2%). Excluding patients with severe head trauma, mortality ranged from 4.5% with nonoperative management to 18.1% and 66.7% in those requiring laparotomy and dual cavitary exploration, respectively.
Tranexamic Acid in Combat Trauma
In a retrospective study of 896 consecutive admissions of US and UK soldiers with combat injuries in Afganistan, who received at least 1 unit of red cells, Morrison compared the outcomes between those who received tranexamic acid (n=293) and those who did not (n=603). Those receiving tranexamic acid had lower unadjusted mortality (17.4% vs 23.9%; P = .03) despite being more severely injured (Injury Severity Score, 25.2 [16.6] vs 22.5 [18.5]; P < .001). This benefit was greatest in the group of patients who received massive transfusion (14.4% vs 28.1%; P = .004), where tranexamic acid was also independently associated with survival (odds ratio = 7.228; 95% CI, 3.016-17.322) and less coagulopathy (P = 0.003).
I hope you find these brief summaries useful.
Until next week
Rob