Capnography in Emergency Medicine

Capnographs measure the concentration of carbon dioxide at the end of each exhaled breath – defined as end-tidal CO2. Read about capnography in emergency medicine and how to monitor critically-ill patients, procedural sedation, cardiopulmonary resuscitation and transportation of ventilated patients within and outside the Emergency Department.

Normal capnograph

Most life-saving articles of 2014?

Of all the articles of importance in emergency medicine in 2014 Medscape has selected the five that could have the greatest impact in helping you save lives. Make sure you read them!

2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes: Executive summary: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines 

Medscape says that the section to be highlighted is the recommendation for urgent catheterization. Patients with NSTE-ACS needing “urgent/immediate invasive strategy” include patients with:

  • refractory angina despite aggressive use of standard antianginal medications
  • evidence of evolving heart failure or worsening mitral regurgitation
  • hemodynamic instability
  • sustained ventricular tachycardia or ventricular fibrillation (excepting patients with serious comorbidities or contraindications to such procedures).

Such patients have been given a Class I indication, level of evidence A, for invasive therapy within 2 hours. Note that immediate catheterization is now indicated for patients who are post-ventricular fibrillation cardiac arrest even in the absence of ST-segment elevation on the ECG.

Full-text available here

A simplified and structured teaching tool for the evaluation and management of pulseless electrical activity

Cardiac arrest victims who present with pulseless electrical activity (PEA) usually have a grave prognosis. Several conditions, however, have cause-specific treatments which, if applied immediately, can lead to quick and sustained recovery. Current teaching focuses on recollection of numerous conditions that start with the letters H or T as potential causes of PEA. This teaching method is too complex, difficult to recall during resuscitation, and does not provide guidance to the most effective initial interventions. This review proposes a structured algorithm that is based on the differentiation of the PEA rhythm into narrow- or wide-complex subcategories, which simplifies the working differential and initial treatment approach. This, in conjunction with bedside ultrasound, can quickly point towards the most likely cause of PEA and thus guide resuscitation.

Full-text available here

Factors associated with the occurrence of cardiac arrest after emergency tracheal intubation in the Emergency Department

This article finds that early post-intubation CA occurred with an approximate 2% frequency in the ED. Systolic hypotension before intubation is associated with this complication, which has potentially significant implications for clinicians at the time of intubation. Medscape says that it is easy to forget that intubation can produce significant haemodynamic compromise which may not be a problem in most patients, but which can cause decompensation in critically ill patients with limited haeomodynamic reserve. The conclusion is that it “seems logical” that  critically ill patients should receive aggressive pre-intubation fluid resus and/or vasopressors to prevent heamodynamic collapse on intubation, although further randomized trials are needed

Full-text available here

And finally two articles from the New England Journal of Medicine which both deal with the management of sepsis

A randomized trial of protocol-based care for early septic shock (Full-text available here) and  Early goal-directed resuscitation for patients with early septic shock (Abstract available here. Full text available from the library on request. Use the request form here).

The primary lesson to take from these articles is that a formal early goal-directed protocol does not improve mortality over non-protocol-based aggressive therapy. Specific interventions are the key to improving mortality:

  • Early recognition is key. Blood cultures should be obtained and broad-spectrum antibiotics initiated without delay. Crystalloids should be provided early and vasopressors added for fluid-resistant shock. When initiating mechanical ventilation it is important to use lung-protective strategies with low tidal volumes
  • Central venous catheters and monitoring ScvO2 do not appear to improve outcomes when used routinely. Rather monitoring serial lactate levels as a measure of perfusion appears to be adequate in general. Blood transfusions should be used less often and are best saved for patients with active cardiac or cerebral ischaemia in the presence of a haemoglobin level < 7 g/dl.