LMA to stoma ventilation

Level 1 evidence is great, but for useful tips that can add options to your resuscitation toolbox there are some great finds in journal letters pages.

Try this one: An apneoic patient requires assisted ventilation in your resuscitation room. Bag-mask ventilation is ineffective. You then notice a mature tracheostomy at the same time that you’re told he had a laryngectomy. How would you ventilate him?

The obvious answer is to intubate the stoma with a size 6.0 tracheal tube or a tracheostomy tube if you have one. However prior to that you could bag-‘mask’ ventilate with a size 2 laryngeal mask airway applied to the stoma, holding the cuff in place with pressure through an index finger.

Such a technique is desribed in the context of an elective anaesthesia case in this month’s Anaesthesia. The LMA cuff provided an effective seal around the stoma, thereby allowing leak-free ventilation.

Stoma ventilation using a paediatric facemask is another option.

Tracheostomy ventilation using a laryngeal mask as a ‘bridge to extubation’
Anaesthesia 2010;65(12):1232–1233

Fibrinogen concentrate

A case report of massive obstetric haemorrhage due to placental abruption describes the successful management of haemorrhage associated with a low fibrinogen level with blood products that included fibrinogen concentrate.

Fibrinogen concentrate can be available more quickly than other clotting products as it is rapidly solubilised from an ampoule in 50 ml water and given as a bolus. To raise the plasma fibrinogen concentration by 1 g/l in a 70-kg person, 1000 ml fresh frozen plasma (6 standard UK units), or 260 ml cryoprecipitate (10 standard UK units) will be required. Administration of adequate doses of fresh frozen plasma or cryoprecipitate to treat hypofibrinogenaemia during obstetric haemorrhage will therefore take a substantial amount of time, even with an efficient blood bank and portering system.

Fibrinogen concentrate use during major obstetric haemorrhage
Anaesthesia 2010;65(12):1229–1230

A previous retrospective study showed its use in a series of surgical and obstetric haemorrhage cases may have been associated with a subsequent decreased need for other blood products.

Fibrinogen concentrate substitution therapy in patients with massive haemorrhage and low plasma fibrinogen concentrations
Br. J. Anaesth. (2008) 101 (6): 769-773 (Full text)

ED US for DVT

Made a radiologist go red with rage recently? If not, you could try showing them this paper1 in this month’s Annals of Emergency Medicine that describes accurate emergency physician ultrasound diagnosis of deep vein thrombosis after just ten minutes training!
ED patients with a suspected lower extremity deep venous thrombosis were assessed using a bedside 2-point compression technique by emergency physicians using a portable US machine and all patients subsequently underwent duplex ultrasonography performed by the Department of Radiology.

The emergency physicians had a 10-minute training session before enrolling patients

The techinque involved 2 specific points: the common femoral and popliteal vessels, with subsequent compression of the common femoral and popliteal veins. The study result was considered positive for proximal lower extremity deep venous thrombosis if either vein was incompressible or a thrombus was visualised.

Free DVT ultrasound tutorial at Sonoguide.com

A total of 47 physicians performed 199 2-point compression ultrasonographic examinations in the ED.
There were 45 proximal lower extremity deep venous thromboses observed on Department of Radiology evaluation, all correctly identified by ED 2-point compression ultrasonography. The 153 patients without proximal lower extremity deep venous thrombosis all had a negative ED compression ultrasonographic result. One patient with a negative Department of Radiology ultrasonographic result was found to have decreased compression of the popliteal vein on ED compression ultrasonography, giving a single false-positive result, yet repeated ultrasonography by the Department of Radiology 1 week later showed a popliteal deep venous thrombosis. The sensitivity and specificity of ED 2-point compression ultrasonography for deep venous thrombosis were 100% (95% confidence interval 92% to 100%) and 99% (95% confidence interval 96% to 100%), respectively.

These figures may appear to fail the ‘sniff test’, ie. seem too good to be true. Not surprisingly Annals acknowledge this by providing an accompanying editorial2 by emergency ultrasound heavyweight Michael Blaivas, MD, who is healthily skeptical of such a minimal training program but is overwhelmingly supportive of the principle. Dr Blaivas also provides a fantastic summary of the existing evidence base on ED ultrasound for DVT. To me he hits the nail on the head when with a philosophical point on the practice of EM: ‘One common challenge proponents of any new application or procedure face in emergency medicine is overcoming the inertia of comfort with the status quo.’ Spot on, Dr B.

1. Compression Ultrasonography of the Lower Extremity With Portable Vascular Ultrasonography Can Accurately Detect Deep Venous Thrombosis in the Emergency Department
Annals of Emergency Medicine 2010;56(6):601-10

2. Point-of-Care Ultrasonographic Deep Venous Thrombosis Evaluation After Just Ten Minutes’ Training: Is This Offer Too Good to Be True?
Annals of Emergency Medicine 2010;56(6):611-3

The guys at ‘EM Live’ have a short video on how to do DVT ultrasound: