Peripheral vasoactive infusions

periph-vasoactive-iconIt is often recommended that vasoactive agents are infused via central lines because of the risk of infiltration and tissue injury. The Children’s Hospital Boston transport team describe transport of 73 infants and children who were treated during interhospital transport with vasoactive medications via a peripheral intravenous line.
Median transport time was only 38 minutes (range 3[!!]-216) and median age was 1 (birth to 19) .
Dopamine monotherapy was given in 66 patients, adrenaline (epinephrine) monotherapy in 2, dobutamine plus phenylephrine in 1, dopamine and epinephrine in 3, and dopamine, dobutamine, and epinephrine in 1 patient.
In this retrospective study no patients developed infiltration or other complications related to peripheral vasoactive agents during interfacility transport. Eleven of the 73 patients, however, did develop infiltrates related to vasoactive infusion after arrival at the accepting institution; all infiltrates involved only minimal blanching and/or erythema, and all resolved without significant intervention and caused no lasting tissue injury. The risk of infiltration rose with increasing medication dose and duration of use.
Interesting that noradrenaline (norepinephrine) wasn’t used. This study is interesting but the overwhelming predominance of dopamine makes it hard to extrapolate this to European or Australasian practice.
The Use of Vasoactive Agents Via Peripheral Intravenous Access During Transport of Critically Ill Infants and Children
Pediatr Emerg Care. 2010 Aug;26(8):563-6

rFVIIa did not reduce trauma mortality

An industry sponsored placebo-controlled multicentre randomised controlled trial has shown no mortality reduction from recombinant activated Factor VII (rFVIIa) in patients with trauma.
rFVIIa acts physiologically by enhancing clot formation in the presence of tissue factor expressed on injured or ischemic vascular subendothelium. It also acts pharmacologically, binding directly to activated platelets, increasing thrombin burst, and promoting the formation of a stable hemostatic plug.
Blunt and/or penetrating trauma patients aged 18 years to 70 years were eligible if they had continuing torso and/or proximal lower extremity bleeding after receiving 4 units of RBCs despite standard hemostatic interventions. There was no 30 day mortality reduction, although fewer blood products were transfused from dosing to 24 hours in the rFVIIa group.
No significant difference was seen in the safety profile of rFVIIa compared with placebo.
The CONTROL trial was terminated early (573 of 1502 patients) after an interim analysis suggested a high likelihood of futility in demonstrating the primary endpoint in the blunt trauma population.
Results of the CONTROL Trial: Efficacy and Safety of Recombinant Activated Factor VII in the Management of Refractory Traumatic Hemorrhage
Journal of Trauma-Injury Infection & Critical Care September 2010 69(3):489-500

Paediatric Tube Cuff Pressures

A paediatric critical care transport service encountered elevated tracheal tube cuff pressures (>30 cmH20) in 41% of 60 consecutive care studied, and over 60 cmH20 in 30%. This measurement was taken on arrival at the bedside, not in flight.
Cuffed tubes are good, but we need to keep an eye on the pressures.
This is in keeping with the results of an adult study previously blogged on this site.
Endotracheal Tube Cuff Pressures in Pediatric Patients Intubated Before Aeromedical Transport
Pediatr Emerg Care. 2010 May;26(5):361-3

Bronchiolitis – not much works

A review article on bronchiolitis reminds us that there is little evidence to support any specific therapies. Bronchodilators, steroids, adrenaline (epinephrine), CPAP, heliox, mucolytics and leukotriene antagonists are all reviewed. Of these, inhaled 3% saline as a mucolytic has some promise in that studies show it to reduce length of stay in admitted patients by one day. CPAP has been shown to reduce pCO2 but evidence of further benefit may have been limited by a lack of adequately powered studies.
Current Therapies in Bronchiolitis
Pediatr Emerg Care. 2010 Apr;26(4):302-7

Alternative toothless mask position

An alternative position for holding the facemask when bag-mask ventilating edentulous patients is described and evaluated. 49 patients with inadequate seal and air leak during two-hand positive-pressure ventilation had significantly improved ventilation as measured by reduced air leak and increased expiratory volume when the caudal end of the mask was repositioned above the lower lip while maintaining neck extension.

Face mask ventilation in edentulous patients: a comparison of mandibular groove and lower lip placement
Anesthesiology. 2010 May;112(5):1190-3

Taming the Ketamine Tiger

A paper of great interest for those of us who spend a lot of time teaching the use of ketamine describes its history from initial synthesis in the early 1960s. Ketamine pioneer Edward F. Domino, M.D describes how it was first given to humans in 1964: ‘Our findings were remarkable! The overall incidence of side effects was about one out of three volunteers. Frank emergence delirium was minimal. Most of our subjects described strange experiences like a feeling of floating in outer space and having no feeling in their arms or legs.

Domino goes on to list interesting anecdotes in ketamine’s history, like how his wife came up with the term ‘dissociative anaesthetic’ and how physicians and their partners experimenting with ketamine in the 1970s tried communicating with dolphins, fell in love, and froze to death in a forest. The pharmacology of ketamine is described along with its effects on pain and even depression.
Taming the ketamine tiger.
Anesthesiology. 2010 Sep;113(3):678-84 Free Full Text

Roc quicker when bicarb added

Interesting…a randomised trial compared rocuronium mixed with saline against rocuronium mixed 1:1 with 8.4% sodium bicarbonate.
The principal finding was that rocuronium mixed with sodium bicarbonate 8.4% is more potent than that of rocuronium alone; it resulted in a more rapid onset time, and a prolonged recovery from the neuromuscular blockade.
It is likely that this effect is because the drug is weakly basic, and the change in pH from 4.01 to 7.78 seen after the addition of sodium bicarbonate 8.4% to rocuronium increases the amount of unionised rocuronium in the solution.
I suppose we could just give a bigger dose if we need to though.
Potency and recovery characteristics of rocuronium mixed with sodium bicarbonate
Anaesthesia. 2010;65(9):899–903