Prehospital IM midazolam for seizures

Intramuscular midazolam is at least as safe and effective as intravenous lorazepam for the prehospital management of status epilepticus. In his blog EM Literature of Note, Dr Ryan Radecki looks forward to a similar trial comparing nasal midazolam, which would reduce the risk from injections. Read his full critique here. Buccal midazolam 0.5 mg/kg is of course also an option, as described in the Advanced Paediatric Life Support manual:
If using the buccal route, draw up the higher dose (0.5mg) of the IV preparation using a needle (to avoid any fragments of glass from the ampoule) and after removing the needle, inject the drug into the buccal area between the lower bottom lip and the gum margin at the side of the mouth. Buccal midazolam is twice as effective as rectal diazepam, but both drugs produce the same level and degree of respiratory depression.


BACKGROUND: Early termination of prolonged seizures with intravenous administration of benzodiazepines improves outcomes. For faster and more reliable administration, paramedics increasingly use an intramuscular route.

METHODS: This double-blind, randomized, noninferiority trial compared the efficacy of intramuscular midazolam with that of intravenous lorazepam for children and adults in status epilepticus treated by paramedics. Subjects whose convulsions had persisted for more than 5 minutes and who were still convulsing after paramedics arrived were given the study medication by either intramuscular autoinjector or intravenous infusion. The primary outcome was absence of seizures at the time of arrival in the emergency department without the need for rescue therapy. Secondary outcomes included endotracheal intubation, recurrent seizures, and timing of treatment relative to the cessation of convulsive seizures. This trial tested the hypothesis that intramuscular midazolam was noninferior to intravenous lorazepam by a margin of 10 percentage points.

RESULTS: At the time of arrival in the emergency department, seizures were absent without rescue therapy in 329 of 448 subjects (73.4%) in the intramuscular-midazolam group and in 282 of 445 (63.4%) in the intravenous-lorazepam group (absolute difference, 10 percentage points; 95% confidence interval, 4.0 to 16.1; P<0.001 for both noninferiority and superiority). The two treatment groups were similar with respect to need for endotracheal intubation (14.1% of subjects with intramuscular midazolam and 14.4% with intravenous lorazepam) and recurrence of seizures (11.4% and 10.6%, respectively). Among subjects whose seizures ceased before arrival in the emergency department, the median times to active treatment were 1.2 minutes in the intramuscular-midazolam group and 4.8 minutes in the intravenous-lorazepam group, with corresponding median times from active treatment to cessation of convulsions of 3.3 minutes and 1.6 minutes. Adverse-event rates were similar in the two groups.
CONCLUSIONS: For subjects in status epilepticus, intramuscular midazolam is at least as safe and effective as intravenous lorazepam for prehospital seizure cessation. (Funded by the National Institute of Neurological Disorders and Stroke and others; ClinicalTrials.gov number, ClinicalTrials.gov NCT00809146.).

Intramuscular versus Intravenous Therapy for Prehospital Status Epilepticus
N Engl J Med. 2012 Feb 16;366(7):591-600

Mathematical Art of M.C. Escher

I am stunned by the beauty and brilliance of this video by Spanish filmmaker Cristóbal VilaInspirations: A Short Film Celebrating the Mathematical Art of M.C. Escher.
M.C. Escher (1898-1972) was the Dutch artist who explored a wide range of mathematical ideas with his woodcuts, lithographs, and mezzotints.
The cool bloggers at openculture.com write: Although Escher had no formal training in mathematics beyond secondary school, many mathematicians counted themselves as admirers of his work.

 
INSPIRATIONS from Cristóbal Vila on Vimeo.
 
 
 
If you want to well up further with rapturous contemplation of the beauty of mathematics in nature, check out his other video, Nature by Numbers

Nature by Numbers from Cristóbal Vila on Vimeo.

Enoxaparin beats heparin for PCI

This is of interest to those of us in retrieval medicine, for logistic reasons: an infusion of heparin can be an unnecessary hassle during transport, especially if a subcutaneous injection prior to retrieval is a satisfactory alternative. This systematic review and meta-analysis shows enoxaparin appears to be superior to unfractionated heparin in reducing mortality and bleeding outcomes during percutaneous coronary intervention. This applies particularly to patients undergoing primary percutaneous coronary intervention for ST elevation myocardial infarction


OBJECTIVE: To determine the efficacy and safety of enoxaparin compared with unfractionated heparin during percutaneous coronary intervention.

DESIGN: Systematic review and meta-analysis.

DATA SOURCES: Medline and Cochrane database of systematic reviews, January 1996 to May 2011.

STUDY SELECTION: Randomised and non-randomised studies comparing enoxaparin with unfractionated heparin during percutaneous coronary intervention and reporting on both mortality (efficacy end point) and major bleeding (safety end point) outcomes.

DATA EXTRACTION: Sample size, characteristics, and outcomes, extracted independently and analysed.

DATA SYNTHESIS: 23 trials representing 30 966 patients were identified, including 10 243 patients (33.1%) undergoing primary percutaneous coronary intervention for ST elevation myocardial infarction, 8750 (28.2%) undergoing secondary percutaneous coronary intervention after fibrinolysis, and 11 973 (38.7%) with non-ST elevation acute coronary syndrome or stable patients scheduled for percutaneous coronary intervention. A total of 13 943 patients (45.0%) received enoxaparin and 17 023 (55.0%) unfractionated heparin. Enoxaparin was associated with significant reductions in death (relative risk 0.66, 95% confidence interval 0.57 to 0.76; P<0.001), the composite of death or myocardial infarction (0.68, 0.57 to 0.81; P<0.001), and complications of myocardial infarction (0.75, 0.6 to 0.85; P<0.001), and a reduction in incidence of major bleeding (0.80, 0.68 to 0.95; P=0.009). In patients who underwent primary percutaneous coronary intervention, the reduction in death (0.52, 0.42 to 0.64; P<0.001) was particularly significant and associated with a reduction in major bleeding (0.72, 0.56 to 0.93; P=0.01).
CONCLUSION: Enoxaparin seems to be superior to unfractionated heparin in reducing mortality and bleeding outcomes during percutaneous coronary intervention and particularly in patients undergoing primary percutaneous coronary intervention for ST elevation myocardial infarction.

Efficacy and safety of enoxaparin versus unfractionated heparin during percutaneous coronary intervention: systematic review and meta-analysis
BMJ. 2012 Feb 3;344:e553

Scandinavian Critical Care

If you like the kind of updates posted here at Resus.ME, then check out SCANCRIT. This blog on anaesthesia, intensive care and emergency medicine – in-hospital and outside – is run by two friends of mine who undersell themselves with their description as ‘two Scandinavian senior anaesthetic registrars’.
These marauding Viking resuscitators are so much more. Lock up your daughters and go to www.scancrit.com

The REAL Shocked Patient

I promised to put some summary notes on the site for those who attended my talk on ‘The REAL Shocked Patient’ for the Australian College of Ambulance Professionals on Tuesday 21st February 2012, so here they are:

Shocked patients are important – they comprise most of the ‘talk and die’ caseload that preoccupies pub conversations between emergency physicians
It’s easy to mistake these patients as less sick than, say, hypoxic ones, but oxygen delivery to the tissues doesn’t just depend on oxygen!

Here’s a dead wombat – someone in the audience knew a worrying amount about wombat anuses.

The 4 Hs and 4 Ts aren’t a very cognitively practical mnemonic for the causes of PEA arrest (which is an extreme form of hypotension)

I prefer the ‘3 plus 3’ rule, which breaks down the causes into three – volume, pump, and obstruction. Obstruction is further broken down into three causes, being tension pneumothorax, cardiac tamponade, and pulmonary embolism:

Let’s look at some cases of shock caused by volume deficit, pump falure, or one of the three causes of obstruction to the circulation:
 
Case 1: The hypotensive motorcyclist
His low back pain suggested pelvic fracture
Think of ‘blood on the floor and four more’ (chest, abdomen, pelvis/retroperitoneum, long bones) and consider non-bleeding causes such as neurogenic (spinal injury), tension pneumothorax, cardiac tamponade, and finally medical causes/iatrogenic (drug) causes.
Don’t underestimate the importance of pelvis and limb splinting as a haemorrhage control technique in blunt trauma
Ultrasound in flight made thoracic or abdominal bleeding very unlikely, and ruled out tamponade and pneumothorax
Although he was hypotensive, no fluids were given, as he was mentating normally and peripherally well perfused, with a radial pulse. If we gave fluid, we would titrate to the presence of a radial pulse (in blunt trauma) but we don’t want to ‘pop the clot’ by elevating the BP, or make him less able to form effective clots by diluting his blood with crystalloid.
Mortality in trauma sharply rises with systolic BP below 105-110, so recalibrate your definition of hypotension in terms of when you might be concerned, and which patients may benefit from triage to a trauma centre.
 
Case 2: The child crushed by a wall
Caution regarding lower limb infusions in patients with abdominal / pelvic injuries – the fluid may not get to the heart.

The classification of shock into four classes is crap. Never let the absence of a tachycardia reassure you.


Intraosseous is awesome, and EZ-IO has the best track record by far.
 
Case 3: The boy stabbed in the upper thigh
In penetrating limb trauma, prehospital options include pressure, elevation, tourniquet, and haemostatic dressings. Foley catheters have been used successfully in transition zones such as the neck or groin.
 
Case 4: Haematemesis
Should we apply the same principles of permissive hypotension to patients with ‘medical’ bleeding?
The Trendelenburg position doesn’t make a lot of sense – no need to head down the patient, although the act of elevating the legs may ‘autoinfuse’ a bolus of blood to the core circulation, and is recommended by some bodies as a first aid manoeuvre for hypotensive patients in the field prior to iv fluids.
 
Case 5: The overdose patient with a low blood pressure but otherwise fine.
When don’t I Worry about hypotension? When the patient is:

  • With it
  • Warm peripherally
  • Weeing
  • and (in hospital) Without a raised lactate


Case 6: Two cases of pump failure: STEMI and complete heart block
Adrenaline infusions can be simply made with a 1mg 1:10000 minijet diluted in a litre of saline and dripped through a peripheral line titrated to BP / HR / mentation / pulses.
In complete heart block (or other bradycardias) with hypotension, percussion pacing is an option of you don’t have access to transcutaneous or transvenous pacing. If you get capture, it’s as effective in terms of stroke volume as a pacing wire.
 
Case 7: Obstructive shock – tamponade cases
…with resolution of hypotension after drainage by emergency physicians who identified the tamponade on ultrasound, even though they didn’t suspect it clinically. It can be a surprise!
 
Case 8: Obstructive shock – tension pneumothorax
Patients are often agitated and won’t lie flat. They may complain of ‘tight’ breathing. Crackles and/or wheezes may be heard. The classic description of deviated trachea, absent breath sounds, and hyperresonance are the exception, not the rule. Be suspicious and always palpate for subcutaneous emphysema.
Don’t assume a needle decompression will work – there is debate about the best site but in some adults a standard needle won’t reach the pleural space. If you need to place more than one needle, go for it. As physicians, we do thoracostomies to ensure we’ve hit the spot.
 
Case 9: Obstructive shock – pulmonary embolism
A tough one prehospital, as the hypotensive ones need fibrinolysis. Fluid may help the hypotension but too much can overdistend the right ventricle which can then impair left ventricular filling, and worsen the patient’s circulatory state. Once again, ultrasound may be invaluable in highlighting PE as a possible cause for shock.
 
Case 10: Penetrating trauma to the ‘box’ – chest and upper abdomen.
If these patients arrest due to tamponade, early (< 10 minutes) clamshell thoracotomy can be life saving, which means it may need to be done pre-hospital by a HEMS physician to provide a chance of survival. Be on the look out for these and if in doubt activate a medical team (in New South Wales). Like with tension pneumothorax, these patients may be extremely agitated as a manifestation of their shock.
 
Case 11: Confused elderly male with pyrexia and smelly urine who appears ostensibly ‘normotensive’
…but how many 82 year olds do you know with a BP of 110/57? His acute confusion may be a manifestation of shock and he needs aggressive evaluation in hospital including a lactate measurement. Don’t be afraid to give this guy fluids in the field – you can make a big difference here.
Here are five of the myths I promised to expose:

So…shocked patients can talk and die. Don’t let that happen. Shocked patients can be normotensive, and hypotensive patients might not be shocked. Have a plan for how you might evaluate the 3+3 causes in your setting and what you can use from your medication and equipment list to manage volume, pump, and obstruction issues. You will save many lives if you become a serious shock detective.

Utstein-like template for physician EMS

Many European and Australasian emergency medical services deploy physicians to the scene. In order to facilitate consistent data reporting and future collaborative research, a working group produced a recommended reporting template. The group consisted of ‘sixteen European experts in the field of pre-hospital care’, and the nine authors of the study were seven Scandinavians, one Italian and one Brit.

Prehospital Care Doctors
They established an Utstein-like template for documenting and reporting in physician-staffed pre-hospital services. The core data set consists of 45 variables grouped in five different categories: “fixed system variables”, “event operational descriptors”, ” patient descriptors”, “process mapping”, and “outcome measures and quality indicators”.

A consensus-based template for documenting and reporting in physician-staffed pre-hospital services
Andreas J Kruger, David Lockey, Jouni Kurola, Stefano Di Bartolomeo, Maaret Castren, Soren Mikkelsen, Hans Morten Lossius
Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine 2011, 19:71 Full Text
Full text PDF

Severe Traumatic Brain Injury in Children

The Brain Trauma Foundation has released updated guidelines on traumatic brain injury in children.
Most of the recommendations are Grade C and therefore based on limited evidence.

Indications for ICP monitoring

Use of intracranial pressure (ICP) monitoring may be considered in infants and children with severe traumatic brain injury (TBI) (Grade C).
Four lines of evidence support the use of ICP monitoring in children with severe TBI:

  • a frequently reported high incidence of intracranial hypertension in children with severe TBI
  • a widely reported association of intracranial hypertension and poor neurologic outcome
  • the concordance of protocol-based intracranial hypertension therapy and best-reported clinical outcomes
  • and improved outcomes associated with successful ICP-lowering therapies.

Threshold for treatment of intracranial hypertension
Treatment of intracranial pressure (ICP) may be considered at a threshold of 20 mm Hg (Grade C).
Sustained elevations in ICP (>20 mm Hg) are associated with poor outcome in children after severe TBI.
Normal values of blood pressure and ICP are age-dependent (lower at younger ages), so it is anticipated that the optimal ICP treatment threshold may be age-dependent.
Cerebral perfusion pressure thresholds
A CPP threshold 40–50 mm Hg may be considered. There may be age-specific thresholds with infants at the lower end and adolescents at the upper end of this range (Grade C).
Survivors of severe pediatric TBI undergoing ICP monitoring consistently have higher CPP values vs. nonsurvivors, but no study demonstrates that active maintenance of CPP above any target threshold in pediatric TBI reduces mortality or morbidity.
CPP should be determined in a standard fashion with ICP zeroed to the tragus (as an indicator of the foramen of Monro and midventricular level) and MAP zeroed to the right atrium with the head of the bed elevated 30°.
Advanced neuromonitoring
If brain oxygenation monitoring is used, maintenance of partial pressure of brain tissue oxygen (PbtO2) >10 mm Hg may be considered.
Neuroimaging
In the absence of neurologic deterioration or increasing intracranial pressure (ICP), obtaining a routine repeat computed tomography (CT) scan >24 hrs after the admission and initial follow-up study may not be indicated for decisions about neurosurgical intervention (Grade C).
Hyperosmolar therapy
Hypertonic saline should be considered for the treatment of severe pediatric traumatic brain injury (TBI) associated with intracranial hypertension. Effective doses for acute use range between 6.5 and 10 mL/kg (of 3%) (Grade B).
Hypertonic saline should be considered for the treatment of severe pediatric TBI associated with intracranial hypertension. Effective doses as a continuous infusion of 3% saline range between 0.1 and 1.0 mL/kg of body weight per hour administered on a sliding scale. The minimum dose needed to maintain intracranial pressure (ICP)
Temperature control
Moderate hypothermia (32–33°C) beginning early after severe traumatic brain injury (TBI) for only 24 hrs’ duration should be avoided.
Moderate hypothermia (32–33°C) be- ginning within 8 hrs after severe TBI for up to 48 hrs’ duration should be considered to reduce intracranial hypertension.
If hypothermia is induced for any indication, rewarming at a rate of >0.5°C/hr should be avoided (Grade B).
Moderate hypothermia (32–33°C) be- ginning early after severe TBI for 48 hrs, duration may be considered (Grade C).
Note: after completion of these guidelines, the committee became aware that the Cool Kids trial of hypothermia in pediatric TBI was stopped because of futility. The implications of this development on the recommendations in this section may need to be considered by the treating physician when details of the study are published.
Cerebrospinal fluid drainage
Cerebrospinal fluid (CSF) drainage through an external ventricular drain may be considered in the management of increased intracranial pressure (ICP) in children with severe traumatic brain injury (TBI).
The addition of a lumbar drain may be considered in the case of refractory intracranial hypertension with a functioning external ventricular drain, open basal cis- terns, and no evidence of a mass lesion or shift on imaging studies (Grade C).
Barbiturates
High-dose barbiturate therapy may be considered in hemodynamically stable patients with refractory intracranial hypertension despite maximal medical and surgical management.
When high-dose barbiturate therapy is used to treat refractory intracranial hy- pertension, continuous arterial blood pressure monitoring and cardiovascular support to maintain adequate cerebral perfusion pressure are required (Grade C).
Decompressive craniectomy for the treatment of intracranial hypertension
Decompressive craniectomy (DC) with duraplasty, leaving the bone flap out, may be considered for pediatric patients with traumatic brain injury (TBI) who are showing early signs of neurologic deterioration or herniation or are developing intracranial hypertension refractory to medical management during the early stages of their treatment (Grade C).
Hyperventilation
Avoidance of prophylactic severe hyperventilation to a PaCO2 If hyperventilation is used in the management of refractory intracranial hypertension, advanced neuromonitoring for evaluation of cerebral ischemia may be considered (Grade C).
Corticosteroids
The use of corticosteroids is not recommended to improve outcome or reduce intracranial pressure (ICP) for children with severe traumatic brain injury (TBI) (Grade B).
Analgesics, sedatives, and neuromuscular blockade
Etomidate may be considered to control severe intracranial hypertension; however, the risks resulting from adrenal suppression must be considered.
Thiopental may be considered to control intracranial hypertension.
In the absence of outcome data, the specific indications, choice and dosing of analgesics, sedatives, and neuromuscular-blocking agents used in the management of infants and children with severe traumatic brain injury (TBI) should be left to the treating physician.
*As stated by the Food and Drug Administration, continuous infusion of propofol for either sedation or the management of refractory intracranial hypertension in infants and children with severe TBI is not recommended (Grade C).
The availability of other sedatives and analgesics that do not suppress adrenal function, small sample size and single-dose administration in the study discussed previously, and limited safety profile in pediatric TBI limit the ability to endorse the general use of etomidate as a sedative other than as an option for single-dose administration in the setting of raised ICP.
Glucose and nutrition
The evidence does not support the use of an immune-modulating diet for the treatment of severe traumatic brain injury (TBI) to improve outcome (Grade B).
In the absence of outcome data, the specific approach to glycemic control in the management of infants and children with severe TBI should be left to the treating physician (Grade C).
Antiseizure prophylaxis
Prophylactic treatment with phenytoin may be considered to reduce the incidence of early posttraumatic seizures (PTS) in pediatric patients with severe traumatic brain injury (TBI) (Grade C).
The incidence of early PTS in pediatric patients with TBI is approximately 10% given the limitations of the available data. Based on a single class III study (4), prophylactic anticonvulsant therapy with phenytoin may be considered to reduce the incidence of early posttraumatic seizures in pediatric patients with severe TBI. Concomitant monitoring of drug levels is appropriate given the potential alterations in drug metabolism described in the context of TBI. Stronger class II evidence is available supporting the use of prophylactic anticonvulsant treatment to reduce the risk of early PTS in adults. There are no compelling data in the pediatric TBI literature to show that such treatment reduces the long-term risk of PTS or improves long-term neurologic outcome.
Guidelines for the Acute Medical Management of Severe Traumatic Brain Injury in Infants, Children, and Adolescents-Second Edition
Pediatr Crit Care Med 2012 Vol. 13, No. 1 (Suppl.)
Read online
Download PDF (617k)
Other Brain Trauma Foundation Guidelines

Posterior pericardiocentesis

Dr Emanuele Catena and colleagues report a case of an adult male who presented 7 days post cardiac surgery with simultaneous pleural and pericardial effucions causing dyspnoea, tachycardia and hypotension.

Old skool pericardiocentesis

His pericardial effusion was posterior which usually requires surgical drainage, but the adjacent left pleural effusion was associated with pulmonary atelectasis and displacement of the lung, allowing them to insert a needle using sonographic guidance first into the pleural space then the pericardial space.
They inserted through the fourth intercostal space 4 cm medially to the left posterior axillary line (with the patient positioned in the semireclining position). They used agitated saline bubbles to confirm first the pleural then the pericardial location of the needle tip. A 30-cm-long catheter was introduced into the posterior pericardium using the Seldinger technique, and serous-haemorrhagic fluid was drained. The catheter was then retracted allowing drainage of the pleural effusion.
The procedure resulted in haemodynamic and respiratory improvement.
The authors summarise:


This case reports the technique of a “back pericardiocentesis” performed under echographic guidance as a valid alternative to surgery in the peculiar situation characterized by the simultaneous presence of a large left pleural effusion. In the presence of a large left pleural effusion, pulmonary atelectasis and displacement of air-filled pulmonary tissue allows ultrasound transmission from a patient’s back to the heart through a liquid interface and needle insertion “from back” to reach the pericardial space.

 
Pericardiocentesis From Back Under Echographic Guidance An Approach for Posterior Pericardial Effusions
Circulation. 2011 Dec 13;124(24):e835-6

Airway lessons relearned


A UK study examined all out-of-operating room intubations over a one month period in nine hospitals1.
Patients whose indication for tracheal intubation was cardiac arrest and who were intubated without the use of drugs were excluded from analysis, as were neonatal intubations.
Disappointing – but not surprising – findings were the lack of universally applied capnography and the use of propofol as the most commonly used induction agent. However more senior intubators were less likely to use propofol than more junior ones (who used it in 93% of intubations!), and the seniors were also more likely to use non-depolarising neuromuscular blocking drugs (NMBDs) than juniors.
The authors report that in seven (4%) patients, pre-oxygenation “was felt to be impossible“. I find it hard to imagine this situation unless RSI is being done on combative patients without prior sedation, which if this is the case makes me shudder.
The authors express their understandable concern over the absence of an alternative airway such as a laryngeal mask in 12% of cases.
Although the adverse event rate seems high, they point out that they used the term ‘adverse events’ rather than ‘complications’ as the events may not be directly attributable to the intubation. In other words, some patients may have been hypoxaemic or hypotensive to start with due to their underlying clinical problem.
I find this study interesting because the results are similar to those reported in a study I and my colleagues conducted a decade ago2, in which ICU intubations were shown to be more hazardous that ED intubations. This can be explained by the higher proportion of patients on ICU with shock and/or respiratory failure. On the other hand, ED patients more commonly required intubation for neurological presentations, with relatively stable cardiorespiratory physiology.
Take a look at the breakdown of cases in the recent study:

and compare this with our findings:

…this is why I have to argue when I hear it occasionally stated that ‘all ED airways are difficult airways’ – some are actually easy, in patients with long stable apnoea times who make great teaching cases.
The authors “speculate that the low rate of hypoxaemia and airway complications may be related to the high proportion of intubations undertaken by those with anaesthesia as a base speciality, and to the almost universal use of NMBDs.” They do not provide strong data to support the first half of their statement. The supplementary data available online indeed show that the majority of intubators were anaesthesia-based, but how their adverse event rates compare with those of the emergency physicians and paediatricians who also undertook intubations is not available.
I don’t want to detract from the important message Dr Bowles and colleagues are conveying: that the lessons from the 4th National Audit Project on major complications of airway management in the UK still need to be applied.
This paper is one aspect of the potentially life-saving work done by this team, which includes the intubation checklist they created.


BACKGROUND: Tracheal intubation is commonly performed outside the operating theatre and is associated with higher risk than intubation in theatre. Recent guidelines and publications including the 4th National Audit Project of the Royal College of Anaesthetists have sought to improve the safety of out-of-theatre intubations.

METHODS: We performed a prospective observational study examining all tracheal intubations occurring outside the operating theatre in nine hospitals over a 1 month period. Data were collected on speciality and grade of intubator, presence of essential safety equipment and monitoring, and adverse events.

RESULTS: One hundred and sixty-four out-of-theatre intubations were identified (excluding those where intubation occurred as part of the management of cardiac arrest). The most common indication for intubation was respiratory failure [74 cases (45%)]. Doctors with at least 6 month’s experience in anaesthesia performed 136 intubations (83%); consultants were present for 68 cases (41%), and overall a second intubator was present for 94 procedures (57%). Propofol was the most common induction agent [124 cases (76%)] and 157 patients (96%) received neuromuscular blocking agents. An airway rescue device was available in 139 cases (87%). Capnography was not used in 52 cases (32%). Sixty-four patients suffered at least one adverse event (39%) around the time of tracheal intubation.

CONCLUSIONS: Out-of-theatre intubation frequently occurs in the absence of essential safety equipment, despite the existing guidelines. The associated adverse event rate is high.

1. Out-of-theatre tracheal intubation: prospective multicentre study of clinical practice and adverse events
Br J Anaesth. 2011 Nov;107(5):687-92


BACKGROUND: Emergency rapid sequence intubation (RSI) performed outside the operating room on emergency patients is the cornerstone of emergency airway management. Complication rates are unknown for this procedure in the United Kingdom and the factors contributing to immediate complications have not been identified.

AIMS: To quantify the immediate complications of RSI and to assess the contribution made by environmental, patient, and physician factors to overall complication rates.

METHODS: Prospective observational study of 208 consecutive adult and paediatric patients undergoing RSI over a six month period.

RESULTS: Patients were successfully intubated by RSI in all cases. There were no deaths during the procedure and no patient required a surgical airway. Patient diagnostic groups requiring RSI are described. Immediate complications were hypoxaemia 19.2%, hypotension 17.8%, and arrhythmia 3.4%. Hypoxaemia was more common in patients with pre-existing respiratory or cardiovascular conditions than in patients with other diagnoses (p<0.01). Emergency department intubations were associated with a significantly lower complication rate than other locations (16.9%; p = 0.004). This can be explained by the difference in diagnostic case mix. Intubating teams comprised anaesthetists, non-anaesthetists, or both. There were no significant differences in complication rates between these groups.
CONCLUSIONS: RSI has a significant immediate complication rate, although the clinical significance of transient events is unknown. The likelihood of immediate complications depends on the patient’s underlying condition, and relevant diagnoses should be emphasised in airway management training. Complication rates are comparable between anaesthetists and non-anaesthetists. The significantly lower complication rates in emergency department RSI can be explained by a larger proportion of patients with comparatively stable cardiorespiratory function.

2. The who, where, and what of rapid sequence intubation: prospective observational study of emergency RSI outside the operating theatre
Emerg Med J. 2004 May;21(3):296-301 Free Full Text

Another reason to be skeptical about collars

More evidence that the obsession with cervical collars is founded on dogma rather than science


Background All trauma patients with a cervical spinal column injury or with a mechanism of injury with the potential to cause cervical spinal injury should be immobilised until a spinal injury is excluded. Immobilisation of the entire patient with a rigid cervical collar, backboard, head blocks with tape or straps is recommended by the Advanced Trauma Life Support guidelines. However there is insufficient evidence to support these guidelines.

Objective To analyse the effects on the range of motion of the addition of a rigid collar to head blocks strapped on a backboard.

Method The active range of motion of the cervical spine was determined by computerised digital dual inclinometry, in 10 healthy volunteers with a rigid collar, head blocks strapped on a padded spine board and a combination of both. Maximal opening of the mouth with all types of immobiliser in place was also measured.

Results The addition of a rigid collar to head blocks strapped on a spine board did not result in extra immobilisation of the cervical spine. Opening of the mouth was significantly reduced in patients with a rigid collar.

Conclusion Based on this proof of principle study and other previous evidence of adverse effects of rigid collars, the addition of a rigid collar to head blocks is considered unnecessary and potentially dangerous. Therefore the use of this combination of cervical spine immobilisers must be reconsidered.

Value of a rigid collar in addition to head blocks: a proof of principle study.
Emerg Med J. 2012 Feb;29(2):104-7