Category Archives: Resus

Life-saving medicine

Acute Med, All Updates, Resus

Valsalva technique in SVT

Investigators at the Royal North Shore Hospital in Sydney (it’s good there) did a literature review to determine the best ‘gold standard’ way of performing a Valsalva manoeuvre for SVT, and assessed success rates before and after its introduction into the ED.

The technique required the patient to lie supine on the bed in a Trendelenberg position, and forcefully expire into a section of suction tubing and pressure gauge for at least 15 seconds and at a pressure of at least 40 mm Hg. The theory behind increased success in a supine position lies in augmenting the patients’ vagal tone and attenuating the sympathetic tone in addition to increased venous return during phase IV of Valsalva. The ‘standardised’ technique improved the rate of successful termination of SVT from 5.3% to 31.7%

Impact of a modified Valsalva manoeuvre in the termination of paroxysmal supraventricular tachycardia
Emerg Med J. 2010 Apr;27(4):287-91

All Updates, PHARM, Resus, Trauma

Pre-hospital RSI

Physicians from HEMS London document their experience of 400 pre-hospital rapid sequence induction / intubations. Their data are consistent with the experience of other similar services and with the emergency airway management literature in general:

  • Failure to intubate is rare
  • Removing cricoid pressure often improves the view
  • A BURP manoeuvre can improve the view and facilitate intubation, but bimanual laryngoscopy / external laryngeal manipulation is better
  • Having an SOP optimises first-pass success rate

Cricoid pressure and laryngeal manipulation in 402 pre-hospital emergency anaesthetics: Essential safety measure or a hindrance to rapid safe intubation?
Resuscitation 2010(81):810–816

All Updates, Resus

Pre-sedation fasting unnecessary

A thorough review of the emergency medicine sedation literature showed there is only one reported case of pulmonary aspiration during emergency procedural sedation, among 4657 adult cases and 17 672 paediatric cases reviewed. The authors of the review remind us that the often (inappropriately in the ED) quoted American Society of Anesthesiology guidelines for fasting prior to general anaesthesia are based on questionable evidence, and there is high-level evidence that demonstrates no link between pulmonary aspiration and non-fasted patients. There is no reason to recommend routine fasting prior to procedural sedation in the majority of patients in the Emergency Department.
An accompanying editorial points out that like other systematic reviews, the methodological flaws of the studies examined are likely to have limited the conclusions of this review.
The review authors and the editorialist agree that despite the lack of evidence linking fasting status to aspiration, selected patients believed to be significantly more prone to aspiration may benefit from risk:benefit assessment prior to sedation.
Something I learned from reading the review: ‘ it is now recognised that asymptomatic aspiration of gastric contents occurs physiologically during normal sleep‘. How about that.
Pre-procedural fasting in emergency sedation
Emerg Med J. 2010 Apr;27(4):254-61

Acute Med, All Updates, ICU, Resus

What fluid in rhabdomyolysis?

Image from the amazing Life in the Fast Lane website - click here to visit

A ‘BestBET‘ from the Emergency Medicine Journal examined the evidence for the use of sodium bicarbonate and/or mannitol in the management of rhabdomyolysis.
The clinical bottom line: there is no quality published evidence that alkaline diuresis is a superior treatment to normal saline alone.
Rhabdomyolysis and the use of sodium bicarbonate and/or mannitol
Emerg Med J. 2010 Apr;27(4):305-8
Full Text at the BestBets site

Acute Med, All Updates, PHARM, Resus

Oxygen in AMI – no benefit, possible harm

A Cochrane review examined the evidence from randomised controlled trials to establish whether routine use of inhaled oxygen in acute myocardial infarction (AMI) improves patient-centred outcomes, the primary outcomes being death, pain and complications.

Three trials involving 387 patients were included and 14 deaths occurred. The pooled relative risk (RR) of death was 2.88 (95% CI 0.88 to 9.39) in an intention-to-treat analysis and 3.03 (95% CI 0.93 to 9.83) in patients with confirmed AMI. While suggestive of harm, the small number of deaths recorded meant that this could be a chance occurrence. Pain was measured by analgesic use. The pooled RR for the use of analgesics was 0.97 (95% CI 0.78 to 1.20).
There is therefore no conclusive evidence from randomised controlled trials to support the routine use of inhaled oxygen in patients with acute AMI. A definitive randomised controlled trial is required.
Oxygen therapy for acute myocardial infarction
Cochrane Review

Acute Med, All Updates, Resus

Stroke thrombolysis benefit decays with time

Pooled results of several trials comparing recombinant tissue plasminogen activator with placebo in ischaemic stroke quantify the profile of benefit and harm for alteplase in broadly selected patients. Generally, alteplase appears to improve the outcome of one in three patients treated between 1 and 3 h from onset and of one in six patients treated in the 3–4·5 h window, but confers no net benefit beyond that time. Benefit may decrease exponentially (according to an accompanying editorial), so if you are a believer then get in there early.
Time to treatment with intravenous alteplase and outcome in stroke: an updated pooled analysis of ECASS, ATLANTIS, NINDS, and EPITHET trials
Lancet. 2010 May 15;375(9727):1695-703

All Updates, ICU, Resus

Misoprostol for PPH

Misoprostol is a prostaglandin analogue with uterotonic activity. It was compared with placebo in its sublingual form in a randomised trial in 1422 women with postpartum haemorrhage and uterine atony. It was given with other uterotonic agents (mostly oxytocin 10IU im or slow iv). The primary outcome was blood loss of 500 mL or more within 60 min after randomisation, and this was similar in both groups.
Misoprostol as an adjunct to standard uterotonics for treatment of post-partum haemorrhage: a multicentre, double-blind randomised trial
Lancet. 2010 May 22;375(9728):1808-13

All Updates, Resus, Trauma

Exsanguinating pelvis – occlude the aorta

Some patients with life-threatening arterial haemorrhage from a pelvic fracture may be peri-arrest prior to transfer to the angiography suite. French authors describe their use of a balloon catheter to occlude the infrarenal aorta to allow resuscitation to achieve sufficient stability for the transfer. As well as exsanguinating pelvic haemorrhage, intra-aortic balloon occlusion has already been described for the treatment of hemorrhagic shock in the case of ruptured abdominal aortic aneurysm, in abdominal trauma, in gastrointestinal bleeding, and in postpartum hemorrhage.
Features of note regarding the technique include:

  • it can be done blind (without radiological guidance)
  • it can be done prior to transfer to a centre with interventional radiology
  • it can be done in cardiac arrest (and has resulted in ROSC and subsequent survival)

The authors are at pains to point out that the intra-aortic balloon occlusion method described in the study ‘should be reserved to patients in critically uncontrollable hemorrhagic shock (CUHS) and is not a first-line treatment of pelvic fractures in hemorrhagic shock.’
Intra-Aortic Balloon Occlusion to Salvage Patients With Life-Threatening Hemorrhagic Shocks From Pelvic Fractures
J Trauma. 2010 Apr;68(4):942-8.

All Updates, Resus, Trauma

Tranexamic acid saves lives in trauma

A convincing, practice-changing trial is a rare thing in major trauma, but here comes a biggie:
The CRASH-2 trial recruited over 20 000 patients from 40 countries (sadly excluding the US because the trial investigators couldn’t afford the insurance – a sign that no large drug company was funding this trial of an inexpensive therapy).
The antifibrinolytic drug tranexamic acid was compared with placebo in adult trauma patients with, or thought to be at risk of, significant haemorrhage. Clinicians were blinded to the intervention and the primary outcome was death in hospital within 4 weeks of injury. Secondary outcomes were vascular occlusive events (myocardial infarction, stroke, pulmonary embolism, and deep vein thrombosis), surgical intervention (neurosurgery, thoracic, abdominal, and pelvic surgery), receipt of blood transfusion, and units of blood products transfused. Treatment groups were balanced with respect to all baseline patient characteristics.

All-cause mortality was significantly reduced with tranexamic acid and the risk of death due to bleeding was significantly reduced. Vascular occlusive events (fatal or non-fatal) did not differ significantly between the groups (and were fewer in the tranexamic acid group compared with the placebo group).
All cause mortality in the tranexamic acid group was (1463/10 060) = 14·5% and in the placebo group was (1613/10 067) = 16·0%. So absolute risk reduction is 1.5% and Number Needed to Treat = 67.
The same trials group is investigating the effect of tranexamic acid in post-partum haemorrhage, in a study known as the WOMAN Trial
Take Home Message: the early administration of tranexamic acid to trauma patients with, or at risk of, significant bleeding reduces the risk of death from haemorrhage with no apparent increase in fatal or non- fatal vascular occlusive events. All-cause mortality was significantly reduced with tranexamic acid.
Effects of tranexamic acid on death, vascular occlusive events, and blood transfusion in trauma patients with significant haemorrhage (CRASH-2): a randomised, placebo-controlled trial
The Lancet, Early Online Publication, 15 June 2010

Acute Med, All Updates, Resus

Thoracic electrical bioimpedance in dyspnoea

Thoracic electrical bioimpedance (TEB) was used in ED patients presenting with dyspnoea to differentiate between cardiac and non-cardiac causes.
The fundamental principle behind TEB is based on Ohm’s law. If a constant electrical current is applied to the thorax, changes in impedance (ΔZ) to flow are equal to changes in voltage drop across the circuit. As a current will always seek the path of lowest resistivity, which in the human body is blood, ΔZ of the thorax will primarily reflect the dynamic changes of blood volume in the thoracic aorta. Changes in thoracic electrical impedance are continuously recorded and processed using a computer algorithm to calculate a number of cardiohaemodynamic parameters such as stroke volume, CO, CI, SVR and systemic vascular resistance index (SVRi).

A cardiac index cut-off of 3.2 l/m/m2 had a 86.7% sensitive (95% CI 59.5% to 98.0%) and 88.9% specific (95% CI 73.9% to 96.8%) for cardiac dyspnoea in the 52 patients studies, of which 15 had cardiac-related dyspnoea.
The study has several limitations including small numbers and using the gold standard of discharge diagnosis.
Thoracic electrical bioimpedance: a tool to determine cardiac versus non-cardiac causes of acute dyspnoea in the emergency department
Emerg Med J. 2010 May;27(5):359-63
Free Full Text