A patient is resuscitated from an out-of-hospital cardiac arrest and is in your emergency department, comatose, with a pulse.
You know that therapeutic hypothermia is indicated and are happy with the protocol for that. You clinically assess for the underlying cause with history, examination, ECG, and other investigations as indicated.
Someone asks you if you want to give some magnesium “as per the guidelines”. As you are wondering what that’s for someone else asks you how long myocardial stunning lasts for and whether that’s the likely cause of hypotension now.
Luckily you avoid getting annoyed with all these reasonable questions by suddenly remembering that there are international recommendations for the management of ‘Post–Cardiac Arrest Syndrome’. You excuse yourself from the room on the pretext of going to the lavatory and quickly find a quiet area where you scan the following article for help:
Post–Cardiac Arrest Syndrome Epidemiology, Pathophysiology, Treatment, and Prognostication
A Consensus Statement From the International Liaison Committee on Resuscitation (American Heart Association, Australian and New Zealand Council on Resuscitation, European Resuscitation Council, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Asia, and the Resuscitation Council of Southern Africa); the American Heart Association Emergency Cardiovascular Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on Cardiopulmonary, Perioperative, and Critical Care; the Council on Clinical Cardiology; and the Stroke Council
Circulation 2008;118;2452-2483 Full Text Article
Ultrasoundpaedia
A useful site containing ultrasound images is Ultrasoundpaedia at 
Pre-hospital intubation experience and outcomes
Hospitals and medical personnel performing high volumes of procedures demonstrate better patient outcomes and fewer adverse events. The relationship between rescuer experience and patient survival for out-of-hospital endotracheal intubation is unknown.
An American study analysing 3 statewide databases with 26,000 records aimed to determine the association between endotracheal intubation experience and patient survival.
In-the-field intubators were EMS paramedics, nurses, and physicians, although paramedics performed more than 94% of out-of-hospital tracheal intubations. Although all air medical rescuers may use neuromuscular- blockade-assisted (rapid sequence) tracheal intubation, select ground EMS units are allowed to use tracheal intubation facilitated by sedatives only; the rest are done ‘cold’.
Patients in cardiac arrest and medical nonarrest experienced increased odds of survival when intubated by rescuers with high procedural experience. In trauma patients, survival was not associated with rescuer experience.
The odds of survival for air medical trauma patients were almost twice that of other patients, which may be related to the use of neuromuscular- blocking agents by air medical crews, or due to more specialised critical care training. The authors suggest that rescuers should perform at least 4 to 12 annual tracheal intubations.
Out-of-Hospital Endotracheal Intubation Experience and Patient Outcomes
Ann Emerg Med. 2010 Jun;55(6):527-537
Craig Venter unveils "synthetic life"
Man creates life using synthetic DNA. Extraordinary effort and talent applied painstakingly for years in pursuit of a goal. Inspiring!
Target Oxygen Saturation in Extreme Prems
1316 infants who were born between 24 weeks 0 days and 27 weeks 6 days of gestation were randomised to one of two different target ranges of oxygen saturation: 85 – 89% vs. 91 – 95%. The primary outcome was a composite of severe retinopathy of prematurity (defined as the presence of threshold retinopathy, the need for surgical ophthalmologic intervention, or the use of bevacizumab), death before discharge from the hospital, or both.
All infants were also randomly assigned to continuous positive airway pressure or intubation and surfactant in a 2-by-2 factorial design.
The rates of severe retinopathy or death did not differ significantly between the lower-oxygen-saturation group and the higher-oxygen-saturation group (28.3% and 32.1%, respectively; relative risk with lower oxygen saturation, 0.90; 95% confidence interval [CI], 0.76 to 1.06; P=0.21). Death before discharge occurred more frequently in the lower-oxygen-saturation group (in 19.9% of infants vs. 16.2%; relative risk, 1.27; 95% CI, 1.01 to 1.60; P=0.04), whereas severe retinopathy among survivors occurred less often in this group (8.6% vs. 17.9%; relative risk, 0.52; 95% CI, 0.37 to 0.73; P<0.001). There were no significant differences in the rates of other adverse events.
An editorial notes that the unmasked trial data showed that the distribution of oxygen saturation levels was within or above the target range in the higher-oxygen-saturation group, but in the lower-oxygen-saturation group, it was about 90 to 95% (i.e., above the target range). The difference in oxygen saturation levels between the groups was about 3 percentage points instead of the 6 percentage points that had been planned. Therefore, this study actually compared saturation levels of about 89 to 97% with saturation levels of 91 to 97%; the results should be ascribed to these higher ranges.
Targeting oxygen saturation levels is difficult, and a recommended oxygen saturation range that is effective yet safe remains elusive. A lower oxygen saturation level significantly reduces the incidence of severe retinopathy of prematurity but may increase the rate of death.
Target Ranges of Oxygen Saturation in Extremely Preterm Infants
N Engl J Med. 2010 May 16. [Epub ahead of print]
Early CPAP versus Surfactant in Extreme Prems
In a randomised, multicentre trial of 1316 infants born between 24 weeks 0 days and 27 weeks 6 days of gestation, infants were randomly assigned to intubation and surfactant treatment (within 1 hour after birth) or to CPAP treatment initiated in the delivery room, with subsequent use of a protocol-driven limited ventilation strategy. The primary outcome was death or bronchopulmonary dysplasia as defined by the requirement for supplemental oxygen at 36 weeks.
Infants who received CPAP treatment, as compared with infants who received surfactant treatment, less frequently required intubation or postnatal corticosteroids for bronchopulmonary dysplasia (P<0.001), required fewer days of mechanical ventilation (P=0.03), and were more likely to be alive and free from the need for mechanical ventilation by day 7 (P=0.01). However the rates of the primary outcome did not differ significantly between the CPAP group and the surfactant group (47.8% and 51.0%, respectively; relative risk with CPAP, 0.95; 95% confidence interval [CI], 0.85 to 1.05).
The infants randomised to CPAP could receive limited invasive ventilation if necessary; 83.1% of the infants in the CPAP group were intubated. They did not include infants who were born at a gestational age of less than 24 weeks, since the results of a pilot trial showed that 100% of such infants required intubation in the delivery room.
This study had a 2-by-2 factorial design in which infants were also randomly assigned to one of two target ranges of oxygen saturation.
Early CPAP versus Surfactant in Extremely Preterm Infants
N Engl J Med. 2010 May 16. [Epub ahead of print]
Carotid Artery Stenting versus Endarterectomy
The Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST) compared the outcomes of carotid-artery stenting with those of carotid endarterectomy among over 2500 patients with symptomatic or asymptomatic extracranial carotid stenosis.
The authors offer the following conclusions:
- Stroke was more likely after carotid artery stenting.
- Myocardial infarction was more likely after carotid endarterectomy, but the effect on the quality of life was less than the effect of stroke.
- Younger patients had slightly fewer events after carotid-artery stenting than after carotid endarterectomy; older patients had fewer events after carotid endarterectomy.
- The low absolute risk of recurrent stroke suggests that both carotid-artery stenting and carotid endarterectomy are clinically durable and may also reflect advances in medical therapy.
Stenting versus Endarterectomy for Treatment of Carotid-Artery Stenosis
NEJM May 26 2010 Published Online
Guidelines for Clostridium Difficile
Guidelines for preventing, detecting, and treating Clostridium Difficile infection from the Infectious Diseases Society of America have been published.
Clinical Practice Guidelines for Clostridium difficile Infection in Adults: 2010 Update by the Society for Healthcare Epidemiology of America (SHEA) and the Infectious Diseases Society of America (IDSA)
Infect Control Hosp Epidemiol 2010;31:431–455 Full Text
Bloodtest Not Pertinent (BNP)
Despite a lack of evidence that it’s useful, many emergency departments have introduced BNP testing. Some smart Australians decided to properly evaluate its benefit the best way possible – with a randomised controlled trial on 612 patients with acute severe dyspnoea. Guess what? Clinician knowledge of BNP values in patients who presented with shortness of breath to the emergency department did not reduce the probability of hospital admission or alter management or length of hospital stay. The study findings do not support indiscriminate BNP testing in all dyspnoea patients, but do not rule out a possible role in patients with milder dyspnoea.
B-type natriuretic peptide testing, clinical outcomes, and health services use in emergency department patients with dyspnea: a randomized trial
Ann Intern Med. 2009 Mar 17;150(6):365-71
PCI and therapeutic hypothermia
Percutaneous coronary intervention did not increase the risk of dysrhythmia, infection, coagulopathy, or hypotension associated with therapeutic hypothermia after cardiac arrest. Intensivists and cardiologists should perhaps agree that this adds to existing evidence that the two therapies are not mutually exclusive.
Feasibility and safety of combined percutaneous coronary intervention and therapeutic hypothermia following cardiac arrest
Resuscitation. 2010 Apr;81(4):398-403