Characteristic ECG signs of LAD occlusion without ST elevation

In a single centre observational study over 10 years of patients undergoing acute PCI of the left anterior descending (LAD) artery, 35 of 1890 (2%) had a distinct non-ST elevation ECG pattern.

The ECG showed ST-segment depression at the J-point of at least 1 mm in the precordial leads with upsloping ST-segments continuing into tall, symmetrical T-waves. Patients also showed a mean J-point elevation of approximately 0.5 mm in lead aVR.

This novel ECG pattern resolved after reperfusion in all included patients.

The authors caution that these electrocardiographic changes may be missed or misdiagnosed as reversible ischaemia, which might substantially delay the transportation to a PCI centre or the start of reperfusion therapy

The authors conclude: “It is important for cardiologists and emergency care physicians to recognise this distinct ECG pattern, so they can triage such patients for immediate reperfusion therapy.”

Image from Dr Smith's ECG Blog

Persistent precordial “hyperacute” T-waves signify proximal left anterior descending artery occlusion
Heart. 2009 Oct;95(20):1701-6

ACEP pneumonia statement

The American College of Emergency Physicians has conducted an evidence review and issued a policy regarding two critical issues surrounding ED management of pneumonia: whether blood cultures should be taken and in what time frame antibiotics should be administered.

The full document is available from the ACEP website:
Clinical Policy: Critical Issues in the Management of Adult Patients Presenting to the Emergency Department With Community-Acquired Pneumonia

Is cervical spine protection always necessary following penetrating neck injury?

This short cut review in the Best Bets format attempted to answer the question: “is cervical spine protection always necessary following penetrating neck injury?”

From the available evidence they draw the following conclusions:

  1. In stab wounds to the neck (with or without neurological deficit) an unstable spinal injury is very unlikely and c-spine immobilisation is not needed
  2. In gunshot wounds the value of cspine immobilisation is limited: for gunshot wounds without neurological deficit no immobilisation is required, while in cases of gunshot wounds with neurological deficit, or where the diagnosis cannot be made (ie, altered mental status), a collar or sandbag is advised once ABCs are stable, with close observation and intermittent removal to inspect and reassess.
  3. In the rare event of penetrating injury with combined blunt force trauma, a collar or sandbag is advised if possible, once ABCs are stable, with intermittent removal to reassess.

Emerg Med J. 2009 Dec;26(12):883-7

Full text at BestBets.org

Can venous blood gases replace arterial gases?

A comprehensive summary of the literature presented by Professor Anne-Maree Kelly in June 2009 at 4ème SYMPOSIUM INTERNATIONAL BLOOD GASES AND CRITICAL CARE TESTING in France can be viewed on her presentation slides at the link below.

She summarises:

  • pH – Close enough agreement for clinical purposes in DKA, isolated metabolic disease; more work needed in shock, mixed disease
  • Bicarbonate – Close enough agreement for clinical purposes in most cases; more work needed in shock, mixed disease, calculated vs measured gap
  • pCO2 – NOT enough agreement for clinical purposes; potential as a screening test
  • Potassium – Insufficient agreement between serum and BG values for clinical purposes
  • Base excess – Insufficient data

Can venous blood gas analysis replace arterial in emergency and critical care?

Spinal imaging and immobilisation may be unnecessary in many GSW patients

A retrospective review of 4204 patients sustaining gunshot wounds (GSW) to the head, neck or torso examined the incidence of spinal cord injury and bony spinal column injury required operative spinal intervention. None of the patients demonstrated spinal instability requiring operative intervention, and only 2/327 (0.6%) required any form of operative intervention for decompression. The authors concluded that spinal instability following GSW with spine injury is very rare, and that routine spinal imaging and immobilisation is unwarranted in examinable patients without symptoms consistent with spinal injury following GSW to the head, neck or torso.
The role of routine spinal imaging and immobilisation in asymptomatic patients after gunshot wounds
Injury. 2009 Aug;40(8):860-3

Cuffed tracheal tubes for children

In a prospective randomised controlled multi-centre trial, cuffed tracheal tubes were compared with uncuffed tubes in 2246 children aged from birth to five years undergoing general anaesthesia. There was no significant difference in post-extubation stridor but the need for tube exchange was 2.1% in the cuffed and 30.8% in the uncuffed groups (P<0.0001).

From the resuscitation point of view, there remain few if any arguments for using an uncuffed tube.

Prospective randomized controlled multi-centre trial of cuffed or uncuffed endotracheal tubes in small children

Br J Anaesth. 2009 Dec;103(6):867-73