Dr Rich Levitan has made an enormous contribution to the science and practice of emergency airway management, as his bibliography demonstrates. In a new article in Emergency Physicians Monthly entitled ‘Demystifying Pediatric Laryngoscopy’, Rich covers some great tips for optimising laryngoscopic view in kids.
Check this excerpt out for an example:
“During laryngoscopy in infants the epiglottis and uvula are often touching; the epiglottis may be located within an inch of the mouth. Often the epiglottis lies against the posterior pharynx, and it is critical to have a Yankauer to dab the posterior pharynx as the laryngoscope is advanced. Hyperextension of the head pushes the base of tongue and epiglottis backwards against the posterior pharyngeal wall, and makes epiglottis identification more difficult”
Gems like this come thick and fast when you hear or read what Rich has to say. Seven years ago I was left reeling after finishing his ‘Airway Cam Guide to Intubation and Practical Emergency Airway Management‘ which profoundly influenced the way I practice and teach emergency airway skills, including on the Critical Care for Emergency Physicians course.
I’ve finally gotten round to booking a place on one of his courses in March in Baltimore. I’ll let you know how it goes. In the mean time, I’d like to point you toward his training videos as a great educational resource, like this one that demonstrates for novice laryngoscopists the difference between the appearances of trachea and oesophagus, the former having recognisable, defined posterior cartilagenous structures:
Demystifying Pediatric Laryngoscopy
Emergency Physicians Monthly January 19, 2011
Category Archives: Resus
Life-saving medicine
RV involved in AMI more often than you think
We know that inferior STEMI may be complicated by right ventricular involvement, which is why I whack a V4R lead on all my inferior AMI patients. A recent study using cardiac magnetic resonance imaging showed that RV oedema and regional or global RV dysfunction were common in anterior infarcts too, although the proportion significantly decreased at four month follow up.
RV abnormalities are contiguous to the jeopardized LV myocardium and do not occur exclusively in inferior LV infarcts, but are found in up to 33% of anterior LV infarcts as well. The presence of RV ischemic injury is associated with early RV dysfunction as well as with RV functional recovery at follow-up.
Right Ventricular Ischemic Injury in Patients With Acute ST-Segment Elevation Myocardial Infarction: Characterization With Cardiovascular Magnetic Resonance.
Circulation. 2010 Oct 5;122(14):1405-12
Improved survival with modified CPR
A large randomised controlled trial1 on out-of-hospital cardiac arrest patients compared standard CPR with CPR augmented by two modifications:
- active compression-decompression using a hand-held suction device to compress the chest. The device is attached to the chest of the patient during CPR and the rescuer actively lifts the chest upwards after each compression, which are done at a rate of 80/min
- augmented negative intrathoracic pressure using an impedance threshold device, which is a valve that limits passive air entry into the lungs during chest compressions, thereby reducing intrathoracic pressure and increasing blood flow to vital organs
The primary study endpoint was survival to hospital discharge with favourable neurological function.
Funding issues resulted in premature cessation of the study. 47 (6%) of 813 controls survived to hospital discharge with favourable neurological function compared with 75 (9%) of 840 patients in the intervention group (odds ratio 1·58, 95% CI 1·07–2·36; p=0·019]. 74 (9%) of 840 patients survived to 1 year in the intervention group compared with 48 (6%) of 813 controls (p=0·03), with equivalent cognitive skills, disability ratings, and emotional-psychological statuses in both groups. The overall major adverse event rate did not differ between groups, but more patients had pulmonary oedema in the intervention group (94 [11%] of 840) than did controls (62 [7%] of 813; p=0·015).
An accompanying editorial2 points out that previous studies in animal models of cardiac arrest gave reassuring results for both devices individually and when used together, but results from clinical trials in patients have been mixed for each device when used individually:
- For compression-decompression CPR, a systematic review pooled the existing data for such CPR versus standard CPR in 4162 patients and found no difference in short-term mortality (relative risk 0·98, 95% CI 0·94–1·03) or survival to hospital discharge (0·99, 0·98–1·01). The 2010 CPR guidelines for the USA and Europe do not recommend the use of compression–decompression CPR alone.
- The most current systematic review for the impedance-threshold device showed a significantly improved early survival (relative risk 1·45, 1·16–1·80), and a short-term improved neurological outcome (2·35, 1·30–4·24); however, improved long- term survival did not reach conventional statistical significance (1·48, 0·91–2·41).
The Resuscitation Outcomes Consortium (ROC) PRIMED study3 showed no survival benefit in 8718 patients randomised to standard CPR with an active or sham impedance-threshold device (the Consortium includes the same investigators as the Lancet paper). This was published as an abstract in Circulation recently.
The editorialist has reservations regarding a change in clinical practice resulting from this new study, partly because the trial was stopped prematurely and enrolment of a larger cohort could have changed the findings, and partly because the open use of both devices might have unintentionally introduced bias into the study. Further validation is recommended.
1. Standard cardiopulmonary resuscitation versus active compression-decompression cardiopulmonary resuscitation with augmentation of negative intrathoracic pressure for out-of-hospital cardiac arrest: a randomised trial
Lancet 2011;377:301-11
2. Augmented CPR: rescue after the ResQ trial
Lancet. 2011 Jan 22;377:276-7
3. The Resuscitation Outcomes Consortium ROC) PRIMED Impedance Threshold Device (ITD) Cardiac Arrest Trial: A Prospective, Randomized, Double-Blind, Controlled Clinical Trial
Circulation 2010; 122: 2215–26 (abstr)
Open thoracostomy
Not a new paper to cite here, just a collection of resources that refer to open thoracostomy in trauma.
A longstanding practice by some European and Australasian HEMS physicians, open thoracostomy is essentially a chest tube procedure without the actual intercostal catheter: the surgical incision is made, blunt dissection is performed, and the pleura penetrated. The wound is then left open.
This is a rapid way of decompressing a tension pneumothorax in a critically injured trauma patient who is intubated. The positive pressure ventilation prevents the thoracostomy wound from acting as an open, ‘sucking’, chest wound.
In many pre-hospital services this is the preferred approach to pleural decompression in an intubated patient, and also forms part of the approach to resuscitation in traumatic cardiac arrest.
Some principles to consider are:
- A tube and drainage system are not necessary for the drainage of air, but should be used if there is signficant haemothorax
- The tissues may re-appose during transport so physiological deterioration should prompt a re-fingering of the thoracostomy to re-establish the drainage tract and allow air to escape
- Standard intravenous cannula devices may be shorter than the distance from chest wall to pleural space in many adults, adding to the inadequacy of needle decompression
- Signs of tension pneumothorax are rarely if ever as obvious as the textbooks suggest – unexplained shock or hypoxaemia in a patient with actual or probably thoracic trauma should prompt consideration of pleural decompression even in the absence of obvious clinical signs of pneumothorax – subtle evidence only may exist, such as palpable subcutaneous emphysema
- This should only be done in intubated patients undergoing positive pressure ventilation!
This video shows the procedure, done by a relative beginner; a slightly larger incision with more assertive dissection would make it faster and more effective
Not yet heard Scott Weingart’s excellent podcast on traumatic arrest, which includes open, or ‘finger’, thoracostomy? You can find it here
Thoracostomy references
Simple Thoracostomy Avoids Chest Drain Insertion in Prehospital Trauma
J Trauma 1996 39(2):373-374
Simple thoracostomy in prehospital trauma management is safe and effective: a 2-year experience by helicopter emergency medical crews
European Journal of Emergency Medicine 2006, 13:276–280
Prehospital thoracostomy
European Journal of Emergency Medicine 2008, 15:283–285
Chest decompression during the resuscitation of patients in prehospital traumatic cardiac arrest
Emerg. Med. J. 2009;26;738-740
Life-saving or life-threatening? Prehospital thoracostomy for thoracic trauma
Emerg Med J 2007;24:305–306
Pre-Hospital and In-Hospital Thoracostomy: Indications and Complications
Ann R Coll Surg Engl. 2008 January; 90(1): 54–57
Needle decompression is inadequate:
Needle Thoracostomy in the Treatment of a Tension Pneumothorax in Trauma Patients: What Size Needle?
J Trauma. 2008;64:111–114
Pre-hospital management of patients with severe thoracic injury
Injury 1995 26(9):581-5
Sux vs Roc in ED RSI
Suxamethonium and rocuronium were compared in a database of prospectively recorded cases of RSI in the emergency department.
A total of 327 RSI were included in the final analyses. All patients received etomidate as the induction sedative and were successfully intubated. Of these, 113 and 214 intubations were performed using succinylcholine and rocuronium, respectively.
- The rate of first-attempt intubation success was similar between the succinylcholine and rocuronium groups (72.6% vs. 72.9%, p = 0.95).
- Median doses used for succinylcholine and rocuronium were 1.65 mg/kg (interquartile range [IQR] = 1.26–1.95 mg/kg) and 1.19 mg/kg (IQR = 1–1.45 mg/kg), respectively.
- The median dose of etomidate was 0.25 mg/kg in both groups.
In this study succinylcholine and rocuronium were equivalent with regard to first-attempt intubation success in the ED. This finding is consistent with previous investigations that used doses between 0.9 and 1.2 mg/kg and found similar intubating conditions to succinylcholine at these higher doses; subgroup analyses of studies using a lower rocuronium dose of 0.6 to 0.7 mg/kg had a relative risk favoring succinylcholine for excellent intubating conditions.
The low (in my view) rate of first-attempt intubation success in both groups was (72.6% vs. 72.9%), does make one wonder whether the intubating clinicians optimised their strategy for first-pass success.
Comparison of Succinylcholine and Rocuronium for First-attempt Intubation Success in the Emergency Department
Acad Emerg Med. 2011;18:11-14
Algorithm for Body Packers
‘Mules’ or body packers are people who transport illegal drugs by packet ingestion into the gastrointestinal tract. A large study of body packers apprehended by United State Customs officials at JFK International Airport, New York describes experience with body packers and an algorithm for conservative and surgical management.
Of 56 patients requiring admission out of a total of 1250 subjects confirmed to be body packers, 25 patients (45%) required surgical intervention, whereas 31 patients (55%) were successfully managed conservatively.
Diagnosis:
- Plain abdominal x-ray was diagnostic in 49 patients (88% of all hospitalised patients).
- Non-contrast CT of the abdomen and pelvis is required if AXR is negative
- Forty-eight per cent of body packers had positive urine toxicology for illicit substances.
Management:
- Indications for intervention included:
- bowel obstruction
- packet rupture/toxicity
- delayed progression of packet transit on conservative management.
- Patients with packets found predominantly in the proximal gastrointestinal tract failed conservative management more frequently than those with packets found in the distal gastrointestinal tract.
Multiple intraoperative manoeuvres were used to remove the foreign bodies:
- gastrotomy
- enterotomy
- colotomy.
Wound infection was the most common complication and is associated with distal enterotomy and colotomy.
The authors recommend a confirmatory radiological study to demonstrate complete clearance of packets
Establishment of a definitive protocol for the diagnosis and management of body packers (drug mules).
Emerg Med J 2011;28:98-10
Hypothermia and hypokalaemia
We all like to treat selected post cardiac arrest patients with hypothermia now, but isn’t hypothermia associated with a drop in potassium, which of course can precipitate pesky ventricular dysrhythmias in patients who would really rather not arrest again. Maybe the hypothermia itself is protective against the dysrhythmias?
A study from the Mayo Clinic updates our knowledge of this area:
METHODS: We retrospectively analyzed potassium variability with Therapeutic Hypothermia (TH) and performed correlative analysis of QT intervals and the incidence of ventricular arrhythmia.
RESULTS: We enrolled 94 sequential patients with OHCA, and serum potassium was followed intensively. The average initial potassium value was 3.9±0.7 mmol/l and decreased to a nadir of 3.2±0.7 mmol/l at 10 h after initiation of cooling (p<0.001). Eleven patients developed sustained polymorphic ventricular tachycardia (PVT) with eight of these occurring during the cooling phase. The corrected QT interval prolonged in relation to the development of hypothermia (p<0.001). Hypokalemia was significantly associated with the development of PVT (p=0.002), with this arrhythmia being most likely to develop in patients with serum potassium values of less than 2.5 mmol/l (p=0.002). Rebound hyperkalemia did not reach concerning levels (maximum 4.26±0.8 mmol/l at 40 h) and was not associated with the occurrence of ventricular arrhythmia. Furthermore, repletion of serum potassium did not correlate with the development of ventricular arrhythmia.
CONCLUSIONS: Therapeutic hypothermia is associated with a significant decline in serum potassium during cooling. Hypothermic core temperatures do not appear to protect against ventricular arrhythmia in the context of severe hypokalemia and cautious supplementation to maintain potassium at 3.0 mmol/l appears to be both safe and effective.
Hypokalemia during the cooling phase of therapeutic hypothermia and its impact on arrhythmogenesis
Resuscitation. 2010 Dec;81(12):1632-6
Body position in poisoning
You come across a patient in the community who has taken an overdose of pills. The ambulance is on its way and you have no medical equipment. Is there any first aid that might help? How should you position the patient if they are unconscious?
Authors of a BestBet in the EMJ searched the literature to answer the three-part question:
In [orally poisoned patients] does [a specific body position] result in [a better outcome for the patient]?
The limited evidence they found from just two papers suggests that drug absorption is lowest in patients lying on their left side, so you might want to consider placing an unconscious overdose patient in the left-sided recovery position prior to definitively managing them in hospital. The theoretical increased risk of pulmonary aspiration on the left side should be considered however. The table shows just how limited this evidence base is – but the idea is an interesting one.
Optimal body position in oral poisoning cases
Emerg Med J 2010;27:952-953 Full text from the BestBets site
Bleeding Tracheostomy
Adapted from the UK Intensive Care Society’s ‘Standards for the care of adult patients with a temporary tracheostomy‘
Bleeding from an established tracheostomy (ie. ‘late bleeding’, as to opposed to peri-operative bleeding that is more common and often benign) may occur because of erosion of blood vessels in and around the stoma site. This is more likely if there has been infection of the stoma site. Such bleeding may settle with conservative management. More worryingly, however, is the prospect of such bleeding being the result of erosion of a major artery in the root of the neck where there has been pressure from the tracheostomy tube itself or the cuff tube. Most commonly, this erosion occurs into the right brachiocephalic artery (also known as the innominate artery), resulting in a tracheo-innominate artery fistula. This situation may be heralded in the preceding hours by a small, apparently insignificant, sentinel bleed. Bleeding from such a fistula will be massive. THIS IS A LIFE-THREATENING EMERGENCY and so decisions need to be rapidly made.
- Call for help– senior medical and nursing staff, other health professionals with tracheostomy care skills (e.g. respiratory therapist, physiotherapist).
- Clear airway – blood clots may need to be suctioned.
- Replace blood products as required
- Bleeding may be temporarily reduced or stopped by applying finger pressure to the root of the neck in the sternal notch, or by inflating the tracheostomy tube cuff (if present) with a 50ml syringe of air. This inflation should be done slowly and steadily to inflate the balloon to a maximum volume without bursting it. Depending on the type and size of the tracheostomy tube this may be anywhere between 10 and 35 ml.
- Urgent referral for surgical exploration must now be made, if not already done so. In addition to an ENT or maxillofacial surgeon, it may be necessary to get help from a vascular surgeon. Sometimes, the damage can only be repaired utilising cardio-pulmonary bypass, and so a cardiothoracic surgeon may also be needed to help.
- Consider palliation – it is well recognised that fatalities occur in this situation, and that this may be the mode of death for some patients with head and neck cancers
Tracheostomy resources
The National Tracheostomy Safety Project at www.tracheostomy.org.uk in the UK aims to allow patients with tracheostomies or laryngectomies to be safely cared for in hospitals.
The site contains a wealth of educational resources of use to the critical care practitioner. For example, have you thought about what do with a laryngectomy patient who presents with dyspnoea, or even apnoea? Remember that although applying oxygen to the face & neck is a default emergency action for all patients with a tracheostomy, these patients cannot be intubated and ventilated through the normal oral route since their tracheostomy is an end stoma – it does not communicate with the mouth:
Compare this with the algorithm for other patients with a tracheostomy, in whom attempts to oxygenate and ventilate, including intubation, can be made in an emergency either from the ‘top end’ (mouth) or via the stoma:
There are also a number of multimedia resources and a link to the UK Intensive Care Society’s Tracheostomy Guidelines