Huge Solar Flare


NASA’s Solar Dynamics Observatory observed this ultraviolet image of one of the most intense solar flares witnessed in the past few months in sunspot 1112. A filament of magnetised material can be seen streaking 500,000 kilometres across the sun’s southern hemisphere. The bright spot just above the filament’s midpoint is UV radiation released from the sunspot. Read More from New Scientist

AED Use in Children Now Includes Infants

From the new 2010 resuscitation guidelines:

For attempted defibrillation of children 1 to 8 years of age with an AED, the rescuer should use a pediatric dose-attenuator system if one is available. If the rescuer provides CPR to a child in cardiac arrest and does not have an AED with a pediatric dose-attenuator system, the rescuer should use a standard AED. For infants (<1 year of age), a manual defibrillator is preferred. If a manual defibrillator is not available, an AED with pediatric dose attenuation is desirable. If neither is available, an AED without a dose attenuator may be used.

Summary: Adult AEDs may be used in all infants and children if there is no child-specific alternative

Highlights of the 2010 American Heart Association Guidelines for CPR and ECC

Cis-atracurium for ARDS

The ACURASYS study of atracurium vs placebo in ARDS: three ml rapid intravenous infusion of 15 mg of cis-atracurium besylate or placebo was administered, followed by a continuous infusion of 37.5 mg per hour for 48 hours. There appeared to be benefits in the intervention group, although the mechanisms are not clear. Further studies are needed.

BACKGROUND: In patients undergoing mechanical ventilation for the acute respiratory distress syndrome (ARDS), neuromuscular blocking agents may improve oxygenation and decrease ventilator-induced lung injury but may also cause muscle weakness. We evaluated clinical outcomes after 2 days of therapy with neuromuscular blocking agents in patients with early, severe ARDS.

METHODS: In this multicenter, double-blind trial, 340 patients presenting to the intensive care unit (ICU) with an onset of severe ARDS within the previous 48 hours were randomly assigned to receive, for 48 hours, either cisatracurium besylate (178 patients) or placebo (162 patients). Severe ARDS was defined as a ratio of the partial pressure of arterial oxygen (PaO2) to the fraction of inspired oxygen (FIO2) of less than 150, with a positive end-expiratory pressure of 5 cm or more of water and a tidal volume of 6 to 8 ml per kilogram of predicted body weight. The primary outcome was the proportion of patients who died either before hospital discharge or within 90 days after study enrollment (i.e., the 90-day in-hospital mortality rate), adjusted for predefined covariates and baseline differences between groups with the use of a Cox model.

RESULTS: The hazard ratio for death at 90 days in the cisatracurium group, as compared with the placebo group, was 0.68 (95% confidence interval [CI], 0.48 to 0.98; P=0.04), after adjustment for both the baseline PaO2:FIO2 and plateau pressure and the Simplified Acute Physiology II score. The crude 90-day mortality was 31.6% (95% CI, 25.2 to 38.8) in the cisatracurium group and 40.7% (95% CI, 33.5 to 48.4) in the placebo group (P=0.08). Mortality at 28 days was 23.7% (95% CI, 18.1 to 30.5) with cisatracurium and 33.3% (95% CI, 26.5 to 40.9) with placebo (P=0.05). The rate of ICU-acquired paresis did not differ significantly between the two groups.

CONCLUSIONS: In patients with severe ARDS, early administration of a neuromuscular blocking agent improved the adjusted 90-day survival and increased the time off the ventilator without increasing muscle weakness. (Funded by Assistance Publique-Hôpitaux de Marseille and the Programme Hospitalier de Recherche Clinique Régional 2004-26 of the French Ministry of Health; ClinicalTrials.gov number, NCT00299650.)

Neuromuscular blockers in early acute respiratory distress syndrome
N Engl J Med. 2010 Sep 16;363(12):1107-16

CAB rather than ABC

The 2010 ILCOR resuscitation guidelines were published today. Key changes and continued points of emphasis from the 2005 BLS Guidelines include the following:

  • Sequence change to chest compressions before rescue breaths (CAB rather than ABC)
  • Immediate recognition of sudden cardiac arrest based on assessing unresponsiveness and absence of normal breathing (ie, the victim is not breathing or only gasping)
  • “Look, Listen, and Feel” removed from the BLS algorithm
  • Encouraging Hands-Only (chest compression only) CPR (ie, continuous chest compression over the middle of the chest) for the untrained lay-rescuer
  • Health care providers continue effective chest compressions/CPR until return of spontaneous circulation (ROSC) or termination of resuscitative efforts
  • Increased focus on methods to ensure that high-quality CPR (compressions of adequate rate and depth, allowing full chest recoil between compressions, minimizing interruptions in chest compressions and avoiding excessive ventilation) is performed
  • Continued de-emphasis on pulse check for health care providers
  • A simplified adult BLS algorithm is introduced with the revised traditional algorithm
  • Recommendation of a simultaneous, choreographed approach for chest compressions, airway management, rescue breathing, rhythm detection, and shocks (if appropriate) by an integrated team of highly-trained rescuers in appropriate settings

2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Part 5: Adult Basic Life Support
Circulation. 2010;122:S685-S705
http://circ.ahajournals.org/cgi/content/full/122/18_suppl_3/S685

New CPR Guidelines

The International Liaison Committee on Resuscitation has published its five-yearly update of resuscitation guidelines.

The American Heart Association Guidelines can be accessed here

The European Resuscitation Guidelines can be accessed here

2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science
Circulation. 2010;122:S639

Evidence refutes ATLS shock classification

I have always had a problem with the ATLS classification of hypovolaemic shock, and omit it from teaching as any clinical applicability and reproducibility seem to be entirely lost on me. I was therefore reassured to read that real physiological data from the extensive national trauma registry in the UK (TARN) of 107,649 adult blunt trauma patients do not strongly support this classification. A key observation we regularly make in trauma patients is the frequent presence of normo- or bradycardia in hypovolaemic patients, which is well documented in the literature.

Unreferenced dogma that became viral

An excellent discussion section in this paper states: ‘it is clear that the ATLS classification of shock that associates increasing blood loss with an increasing heart rate, is too simplistic. In addition, blunt injury, which forms the majority of trauma in the UK, is usually a combination of haemorrhage and tissue injury and the classification fails to consider the effect of tissue injury

Testing the validity of the ATLS classification of hypovolaemic shock
Resuscitation. 2010 Sep;81(9):1142-7

In-flight cooling after out-of-hospital cardiac arrest

Aeromedical retrieval specialists in Scotland developed a simple, cheap, effective in-flight cooling protocol using intravenous (IV) cold Hartmann’s solution and chemical cooling packs. Fluids cooled in a fridge (4°C) were transported in an insulated cool box; the patient was sedated, paralysed and intubated, and controlled ventilation started. The patient was then cooled by IV infusion of 30 ml/kg of cold Hartmann’s. Chemical ice packs were activated and placed in the axillae and groin. The time interval between successful resuscitation and the patient being retrieved and flown to an Intensive Care Unit (ICU) was at least 3.5 h. Cooled patients had a mean decrease in body temperature during retrieval compared to patients not cooled (−1.6 °C vs. +0.9 °C, p = 0.005) and a lower body temperature on ICU arrival (34.1 °C vs. 36.4 °C, p = 0.05). Two of the 5 cooled patients achieved target temperature (<34 °C) before ICU arrival. No complications of in-flight cooling were reported.

Not the only way to cool down in Scotland

In-flight cooling after out-of-hospital cardiac arrest
Resuscitation. 2010 Aug;81(8):1041-2

Burr holes by emergency physicians

Emergency physicians at Hennepin County Medical Centre (HCMC) are trained in skull trephination (drilling a burr hole) for patients with coma, anisocoria and epidural (extradural) haematoma (EDH) who have not responded to osmotic agents and hyperventilation. This may be particularly applicable in centres remote from neurosurgical centres where delays caused by interfacility transfer are associated with increased morbidity and mortality.

Dr Smith and colleagues from HCMC describe a series of five talk-and-deteriorate patients with EDH who underwent skull trephination. 3 had complete recovery without disability, and 2 others had mild to moderate disability but with good to excellent cognitive function. None had complications from the procedure other than external bleeding from the already lacerated middle meningeal artery. In 4 of 5 cases, the times were recorded. Mean time from ED presentation to trephination was 55 min, and mean time from ED to craniotomy was 173 min. The mean time saved was 118 min, or approximately 2 h.

All trephinations were done by emergency physicians, who had received training in skull trephination as part of the HCMC Emergency Medicine Residency or as part of the Comprehensive Advanced Life Support (CALS) course. Training was very brief and involved discussion of the treatment of EDH, review of a CT scan of EDH, and hands-on practice on the skull of a dead sheep, using the Galt trephinator.

An excellent point made by the authors reminds us that patients with EDH who talk-and-deteriorate (those with the traditionally described “lucid interval”) have minimal primary brain injury and frequently have no brain parenchymal injury. Thus, if the EDH is rapidly decompressed, the outcome is significantly better than for deterioration due to other aetiologies. The authors recommend in EDH that the procedure should be done within 60–90 min of onset of anisocoria. A review of other studies on the procedure would suggest that case selection is critical in defining the appropriateness of the procedure: talk-and-deteriorate, coma, anisocoria, and a delay to neurosurgical decompression.

Emergency Department Skull Trephination for Epidural Hematoma in Patients Who Are Awake But Deteriorate Rapidly
J Emerg Med. 2010 Sep;39(3):377-83