Category Archives: All Updates

All Updates, Guidelines, Resus, Trauma

Stab wounds to the neck

An algorithm for the management of patients with stab wounds to the neck has been proposed by authors of a review of the topic.
‘Hard’ signs of vascular injury include severe active bleeding, unresponsive shock, evolving stroke, and large/expanding haematoma. ‘Soft’ signs include a non-expanding moderate haematoma, a bruit/thrill, or a radial pulse deficit (although some consider the latter two to be hard signs). Mentioned in the text, but omitted from the algorithm, is the option of placing a Foley catheter into the wound and inflating the balloon to blindly control bleeding in a crashing haemodynamically unstable patient in order to buy time to get to the operating room.

Review article: Emergency department assessment and management of stab wounds to the neck.
Emerg Med Australas. 2010 Jun;22(3):201-10

All Updates, ICU, Resus, Ultrasound

Saline can be used in place of US gel

A study comparing sterile saline as a conduction agent with ultrasound gel showed adequate visualization of anatomic structures for ultrasound-guided vascular access. The authors state that given sterile saline’s theoretical advantages over gel in terms of availability, cost, safety and ease of use in the procedural field, it should be considered as a viable alternative to gel as a conduction agent.

Saline - so many uses we hadn't thought of

Use of sterile saline as a conduction agent for ultrasound visualization of central venous structures
Emerg Med Australas. 2010 Jun;22(3):232-5

All Updates, ICU, Kids, PHARM, Resus

Etomidate in RSI – systematic review

A systematic review of 20 included studies comparing a bolus dose of etomidate for rapid sequence induction with other induction agents resulted in the following conclusion:
“The available evidence suggests that etomidate suppresses adrenal function transiently without demonstrating a significant effect on mortality. However, no studies to date have been powered to detect a difference in hospital, ventilator, or ICU length of stay or in mortality”
The Effect of a Bolus Dose of Etomidate on Cortisol Levels, Mortality, and Health Services Utilization: A Systematic Review
Ann Emerg Med. 2010 Aug;56(2):105-13

All Updates, PHARM

Tracheal tube cuff pressure in flight

Tracheal tube cuff pressures increased from a mean 28.7 cm H2O pre-flight to 62.6 cm H2O in flight (mean altitude increase 2260 feet) in a Swiss helicopter-based study.
At cruising altitude, 98% of patients had intracuff pressure >30 cm H2O, 72% had intracuff pressure>50 cm H2O, and 20% even had intracuff pressure>80 cm H2O.
Multiple different referring hospitals meant the type of tracheal tube was not controlled for.

Endotracheal Tube Intracuff Pressure During Helicopter Transport
Ann Emerg Med. 2010 Aug;56(2):89-93

Acute Med, All Updates, ICU, Resus

Complex acid-base problems

Working out the expected compensatory response to an acid base disturbance often reveals a second acid-base problem that was otherwise hidden. I regularly use Winter’s formula when I see a metabolic acidosis, but I have trouble remembering the others, so here they are, from Harwood-Nuss’ Clinical Practice of Emergency Medicine (apologies if you ‘think’ in kilopascals):
Formulas Describing Expected Compensatory Response to Primary Acid–Base Disturbances
Simple Metabolic Acidosis

  • Predicted decreased PCO2 mm Hg = 1.2 × Δ(HCO3-) mEq/L
  • Predicted PCO2 mm Hg = 1.5(HCO3-) mEq/L + 8 ± 2
  • Anticipated PCO2 approximates last two digits of arterial pH

Simple Metabolic Alkalosis

  • Predicated increased Δ PCO2 mm Hg = 0.67 × Δ(HCO3-) mEq/L

Simple Acute Respiratory Acidosis

  • Predicted decreased ΔpH units = 0.8 × Δ PCO2 mm Hg
  • Predicted increased Δ(HCO3-) mEq/L = 0.1 × Δ PCO2 mm Hg

Simple Chronic Respiratory Acidosis

  • Predicted decreased ΔpH units = 0.3 × Δ PCO2 mm Hg
  • Predicted increased Δ(HCO3-) mEq/L = 0.35 × Δ PCO2 mm Hg

Simple Acute Respiratory Alkalosis

  • Predicted increased ΔpH units = 0.8 × Δ PCO2 mm Hg
  • Predicted decreased Δ(HCO3-) mEq/L = 0.2 × Δ PCO2 mm Hg

Simple Chronic Respiratory Alkalosis

  • Predicted increased ΔpH units = 0.17 × Δ PCO2 mm Hg
  • Predicted decreased Δ(HCO3-) mEq/L = 0.5 × Δ PCO2 mm Hg
All Updates, ICU, Resus

Femoral SvO2 not so useful

Bloods sampled from both femoral vein and SVC-sited catheters in critically ill patients showed good correlation in lactate levels but the oxygen saturation was not so reliable, with >5% variation in more than 50% and >15% variation in some patients. The authors suggest one reason is that the femoral catheter tip usually sits in the iliac vein and samples blood prior to the mixing of blood returning from intra-abdominal organs. They advise caution in using SfvO2 to guide resuscitation when narrow end points are used, as this may lead to inappropriate vasoactive drug or blood component therapy.

Femoral-Based Central Venous Oxygen Saturation Is Not a Reliable Substitute for Subclavian/Internal Jugular-Based Central Venous Oxygen Saturation in Patients Who Are Critically Ill
Chest. 2010 Jul;138(1):76-83

All Updates, ICU, Resus

ALI / ARDS strategies

A CME article in Critical Care Medicine summarises the literature on ARDS (including its limitations) and provides evidence based recommendations on what to do about severe hypoxaemia. They summarise:
For life-threatening hypoxaemia, initial management with a recruitment manoeuvre and/or high PEEP should be undertaken if plateau airway pressures and lack of barotrauma allow. If not, or if these are not effective, then proceed to the prone position or HFOV. If hypoxemia still persists, then consider the administration of inhaled NO. If NO fails, then glucocorticoids can then be administered. For elevated plateau airway pressures when tidal volumes are 4 mL/kg, consider prone positioning or HFOV. For life- threatening respiratory acidosis, consider the use of a buffer or continuous veno-venous hemofiltration. It is most important to assess for objective physiologic improvement in the appropriate time period for each intervention. If no benefit is evident, then the therapy should be discontinued to minimise harm and delay in the initiation of another therapy. If the patient continues to have life-threatening hypoxemia, acidosis, or elevated plateau airway pressures, then consider ECMO or extracorporeal carbon dioxide removal.


Therapeutic strategies for severe acute lung injury
Crit Care Med. 2010 Aug;38(8):1644-50

All Updates, Guidelines, Kids

Brain tumours in kids

When might you suspect a brain tumour in a child who presents with, say, nausea and vomiting, or behavioural disturbance? A guideline has been produced which might prompt one to think of this important but often delayed diagnosis.

The diagnosis of brain tumours in children: a guideline to assist healthcare professionals in the assessment of children who may have a brain tumour Arch Dis Child. 2010 Jul;95(7):534-9

All Updates, Resus, Trauma, Ultrasound

Ultrasound of intracranial haematoma

Using a 2Mhz transducer insonating through the temporal acoustic bone window, Italian physicians detected the expansion of an extradural haematoma. In their discussion they highlight that transcranial sonography of brain parenchyma in adults has been proposed by several authors for the evaluation of the ventricular system, monitoring of midline shift, diagnosis and follow-up of intracranial mass lesions. In one study, of 151 patients, 133 (88%) had a sufficient acoustic bone window. Note that the skull contralateral to the acoustic bone window is visualised.

Arrow indicates EDH; asterisk indicates mesencephalon

Bedside detection of acute epidural hematoma by transcranial sonography in a head-injured patient
Intensive Care Med. 2010 Jun;36(6):1091-2