Tag Archives: anaesthesia

Massive haemorrhage guideline

The Association of Anaesthetists of Great Britain and Ireland has published guidelines on the management of massive haemorrhage. Their summary:

  1. Hospitals must have a major haemorrhage protocol in place and this should include clinical, laboratory and logistic responses.
  2. Immediate control of obvious bleeding is of paramount importance (pressure, tourniquet, haemostatic dressings).
  3. The major haemorrhage protocol must be mobilised immediately when a massive haemorrhage situation is declared.
  4. A fibrinogen < 1 g.l)1 or a prothrombin time (PT) and activated partial thromboplastin time (aPTT) of > 1.5 times normal represents established haemostatic failure and is predictive of microvascular bleeding. Early infusion of fresh frozen plasma (FFP; 15 ml.kg)1) should be used to prevent this occurring if a senior clinician anticipates a massive haemorrhage.
  5. Established coagulopathy will require more than 15 ml.kg)1 of FFP to correct. The most effective way to achieve fibrinogen replacement rapidly is by giving fibrinogen concentrate or cryoprecipitate if fibrinogen is unavailable.
  6. 1:1:1 red cell:FFP:platelet regimens, as used by the military, are reserved for the most severely traumatised patients.
  7. A minimum target platelet count of 75 · 109.l)1 is appropriate in this clinical situation.
  8. Group-specific blood can be issued without performing an antibody screen because patients will have minimal circulating antibodies. O negative blood should only be used if blood is needed immediately.
  9. In hospitals where the need to treat massive haemorrhage is frequent, the use of locally developed shock packs may be helpful.
  10. Standard venous thromboprophylaxis should be commenced as soon as possible after haemostasis has been secured as patients develop a prothrombotic state following massive haemorrhage.

Blood transfusion and the anaesthetist: management of massive haemorrhage – full document

Rocuronium reusable after sugammadex

Sugammadex currently has no role in my own emergency / critical care practice. However a helpful paper informs us that patients whose rocuronium-induced neuromuscular blockade had been reversed by sugammadex may be effectively re-paralysed by a second high dose (1.2 mg/kg) of rocuronium. Onset was slower and duration shorter if the second dose of rocuronium was given within 25 minutes of the sugammadex.

The study was done with sixteen volunteers and the initial dose of roc was only 0.6 mg/kg – less than that used for rapid sequence intubation by many emergency & critical care docs.
When repeat dose roc was given five minutes after sugammadex (n=6), mean (SD) onset time maximal block was 3.06 (0.97) min; range, 1.92–4.72 min. For repeat dose time points ≥25 min after sugammadex (n=5), mean onset was faster (1.73 min) than for repeat doses <25 min (3.09 min) after sugammadex. The duration of block ranged from 17.7 min (rocuronium 5 min after sugammadex) to 46 min (repeat dose at 45 min) with mean durations of 24.8 min for repeat dosing <25 min vs 38.2 min for repeat doses ≥25 min.
Repeat dosing of rocuronium 1.2 mg kg−1 after reversal of neuromuscular block by sugammadex 4.0 mg kg−1 in anaesthetized healthy volunteers: a modelling-based pilot study
Br J Anaesth. 2010 Oct;105(4):487-92

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

Bad news for etomidate from CORTICUS

In an a priori substudy of the CORTICUS multi-centre, randomised, double-blind, placebo-controlled trial of hydrocortisone in septic shock, the use and timing of etomidate administration was examined in relation to outcome.
Of 499 analysable patients, 96 (19.2%) received etomidate within the 72 h prior to inclusion. The proportion of non-responders to ACTH was significantly higher in patients who were given etomidate than in other patients (61.0 vs. 44.6%, P = 0.004). Etomidate therapy was associated with a higher 28-day mortality in univariate analysis (P = 0.02) and after correction for severity of illness (42.7 vs. 30.5%; P=0.06 and P=0.03) in two multi-variant models. Hydrocortisone administration did not change the mortality of patients receiving etomidate (45 vs. 40%).
Some of the previous attacks on etomidate have not been founded on the most rigorous evidence. However this study adds further to the difficulty in justifying etomidate’s use when a perfectly acceptable alternative (ketamine) exists for rapid sequence induction in the haemodynamically unstable septic patient.
The effects of etomidate on adrenal responsiveness and mortality in patients with septic shock.
Intensive Care Med. 2009 Nov;35(11):1868-76

Cricoid pressure squashes kids' airways

A bronchoscopic study of anaesthetised infants and children receiving cricoid pressure revealed the procedure to distort the airway or occlude it by more than 50% with as little as 5N of force in under 1s and between 15 and 25N in teenagers. Therefore forces well below the recommended value of 30 N will cause significant compression/distortion of the airway in a child

Effect of cricoid force on airway calibre in children: a bronchoscopic assessment
Br J Anaesth. 2010 Jan;104(1):71-4

A novel jaw thrust device

A novel jaw thrust device (JTD) was tested against oropharyngeal and nasopharyngeal airways in anaesthetised patients. The JTD enabled effective ventilation with less airway resistance than the traditional airways, and so provided greater tidal volumes during pressure controlled ventilation. It fits into the mouth, keeping the mouth open and the jaw thrusted forward, and has a standard sized connector for attachment to ventilation devices.

Optimising the unprotected airway with a prototype Jaw-Thrust-Device – a prospective randomised cross-over study
Anaesthesia. 2009 Nov;64(11):1236-40

Take bloods before giving Lipid Rescue

Intralipid therapy is recommended for local anaesthetic toxicity and in some overdoses. After large doses of Intralipid, the results of blood tests may be difficult to analyse, delayed, or spuriously abnormal. If possible, all blood tests should be taken before the administration of Intralipid. While laboratories will readily identify significant lipaemia, communication about the presence of Intralipid is important. In one case, the inability to obtain a haemoglobin result led to delay in the identification of haemorrhage which was the cause of deterioration initially thought to be local anaesthetic toxicity.
Possible side effects of Intralipid rescue therapy
Anaesthesia 2010;65(2):210-11