More on Rocuronium (and Sugammadex)

While I am gradually being persuaded rocuronium might after all be a better choice than suxamethonium for rapid sequence intubation in critically ill patients- partly due to its relative preservation of apnoea time before desaturation in elective anaesthesia patients1 – I don’t believe that the existence and availability of its reversal agent, sugammadex, should really sway us in critical care. After all, we’re usually committed to getting an airway of some description (tracheal tube, supraglottic airway, or cricothyrotomy), and the relatively short duration of suxamethonium has never allowed me to ‘wake someone up and cancel the case’ in a critical care scenario. In fact, with sux, even healthy patients will desaturate before it wears off 2-4 if one is unable to intubate or ventilate.

But could we give sugammadex and reverse the rocuronium in time to save the patient in a can’t intubate/can’t ventilate (CICV) situation? This was tested in a simulation that studied the total time taken for anaesthetic teams to prepare and administer sugammadex from the time of their initial decision to use the drug5. The mean (SD) total time to administration of sugammadex was 6.7 (1.5) min, following which a further 2.2 min (giving a total 8.9 min) should be allowed to achieve a train-of-four ratio of 0.9. Four (22%) teams gave the correct dose, 10 (56%) teams gave a dose that was lower than recommended.
A reply to this article6 recommended some steps to speed up and improve the process:

  1. Brief the team that rocuronium is to be used and that should an unanticipated difficult airway situation be encountered, then sugammadex will be used to reverse the effects of the rocuronium.
  2. Allocate the task of drawing up the sugammadex to a specific team member who has no additional role in the rapid sequence induction.
  3. Before induction, a calculation is made of the dose of sugammadex (16 mg/kg) that would be required and the volume of drug that should be drawn up.
  4. The instruction is given that should the anaesthetist not confirm intubation within 2 min, then the sugammadex is to be drawn up and handed to the anaesthetist for administration.

There are of course rare situations where sugammadex can be a nuisance – it hangs around in renal failure and a recent case report 7described rocuronium (50mg followed by 30mg, patient weight not stated) failing to work on an elderly man who had received sugammadex 16 hours earlier! The authors of this case report state that in healthy patients, the mean cumulative percentage of sugammadex excreted in the urine over 24 h is 48–86%; therefore, a period of 24 h is recommended before a second administration of rocuronium. However, a good dose of rocuronium (1.2 mg/kg) should be effective after sugammadex reversal in previously healthy patients, but a study showed onset was slower and duration shorter if the second dose of rocuronium was given within 25 minutes of the sugammadex8.
So what are the take home points here? For me, the issues are:

  • Suxamethonium offers no real advantages over rocuronium for RSI in critical care – rocuronium at a dose of 1.2 mg/kg will provide similar intubating conditions to a good dose of sux9
  • Whatever you use, you need a rescue plan (supraglottic airway or transtracheal airway) for the CICV scenario
  • Sugammadex is a useful reversal agent in elective anaesthesia but is unlikely to be useful in a critical care scenario; however, if its use is anticipated it needs to be rehearsed as a standardised drill
  • Most of the literature on these agents pertains to well patients undergoing elective anaesthesia and we should be cautious about extrapolating results to the critical care setting
  • Finally, the urgency of a CICV can be reduced by CICVBCO – ‘can’t intubate, can’t ventilate, but CAN oxygenate’ – apnoeic diffusion oxygenation should be employed using pharyngeal or nasal oxygen10. Such a simple but underutilised technique can hugely improve the safety of RSI in critical care, and is described here.

1. Effect of suxamethonium vs rocuronium on onset of oxygen desaturation during apnoea following rapid sequence induction
Anaesthesia. 2010 Apr;65(4):358-61
2. Critical hemoglobin desaturation will occur before return to an unparalyzed state following 1 mg/kg intravenous succinylcholine.
Anesthesiology. 1997 Oct;87(4):979-8
3. Hemoglobin desaturation after succinylcholine-induced apnea: a study of the recovery of spontaneous ventilation in healthy volunteers.
Anesthesiology. 2001 May;94(5):754-9
4. Succinylcholine dosage and apnea-induced hemoglobin desaturation in patients
Anesthesiology. 2005 Jan;102(1):35-40
5. Can sugammadex save a patient in a simulated ‘cannot intubate, cannot ventilate’ situation?
Anaesthesia. 2010 Sep;65(9):936-41
6. Can sugammadex save a patient in a simulated ‘cannot intubate, cannot ventilate’ situation?
Anaesthesia. 2011 Mar;66(3):223-4
7. Unexpected failure of rocuronium-mediated neuromuscular blockade
Anaesthesia. 2011 Jan;66(1):58-9
8. 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
9. Comparison of Succinylcholine and Rocuronium for First-attempt Intubation Success in the Emergency Department
Acad Emerg Med. 2011;18:11-14
10. Critical hemoglobin desaturation can be delayed by apneic diffusion oxygenation
Anesthesiology. 1999 Jan;90(1):332-3

Neuromuscular blockade facilitates mask ventilation

A blinded randomised controlled trial of rocuronium versus saline in anaesthetised patients demonstrated that mask ventilation was easier in paralysed patients.
The authors comment on the implications of this finding:
Our finding that neuromuscular blockade facilitates mask ventilation has important implications for the practice of managing difficult or impossible mask ventilation after administration of these drugs. Options in this case include returning to spontaneous ventilation, tracheal intubation, placement of a supraglottic airway device or obtaining emergency invasive airway access. In most cases, returning to spontaneous ventilation is not practical in a reasonable time frame, leaving tracheal intubation, supraglottic airway placement or emergency invasive airway access as the only feasible choices. Considerable evidence exists indicating that neuromuscular blockade facilitates tracheal intubation; and since our data further indicate that neuromuscular blockade facilitates mask ventilation, it follows that administering neuromuscular blockade is an advantage, rather than a hindrance when given early in a case of unrecognised difficult mask ventilation.
We wished to test the hypothesis that neuromuscular blockade facilitates mask ventilation. In order reliably and reproducibly to assess the efficiency of mask ventilation, we developed a novel grading scale (Warters scale), based on attempts to generate a standardised tidal volume. Following induction of general anaesthesia, a blinded anaesthesia provider assessed mask ventilation in 90 patients using our novel grading scale. The non-blinded anaesthesiologist then randomly administered rocuronium or normal saline. After 2 min, mask ventilation was reassessed by the blinded practitioner. Rocuronium significantly improved ventilation scores on the Warters scale (mean (SD) 2.3 (1.6) vs 1.2 (0.9), p<0.001). In a subgroup of patients with a baseline Warters scale value of >3 (i.e. difficult to mask ventilate; n=14), the ventilation scores also showed significant improvement (4.2 (1.2) vs 1.9 (1.0), p=0.0002). Saline administration had no effect on ventilation scores. Our data indicate that neuromuscular blockade facilitates mask ventilation. We discuss the implications of this finding for unexpected difficult airway management and for the practice of confirming adequate mask ventilation before the administration of neuromuscular blockade.
The effect of neuromuscular blockade on mask ventilation
Anaesthesia. 2011 Mar;66(3):163-7

Nasal cooling method

More data on the RhinoChill device from an in-hospital study of post-cardiac arrest patients in Germany. The RhinoChill device (BeneChill Inc., San Diego, USA) allows evaporative cooling by spraying an inert liquid coolant (a perfluorochemical) into the nasal cavity. The liquid evaporates instantaneously, thereby removing heat. It can make your nose discoloured, and in one patient with cardiogenic shock, tissue damage of nose and cheeks due to freezing occurred. Several of the authors are linked with the company that manufactures the device.

AIM: Mild therapeutic hypothermia improves survival and neurologic recovery in primary comatose survivors of cardiac arrest. Cooling effectivity, safety and feasibility of nasopharyngeal cooling with the RhinoChill device (BeneChill Inc., San Diego, USA) were determined for induction of therapeutic hypothermia.
METHODS: Eleven emergency departments and intensive care units participated in this multi-centre, single-arm descriptive study. Eighty-four patients after successful resuscitation from cardiac arrest were cooled with nasopharyngeal delivery of an evaporative coolant for 1h. Subsequently, temperature was controlled with systemic cooling at 33 degrees C. Cooling rates, adverse events and neurologic outcome at hospital discharge using cerebral performance categories (CPC; CPC 1=normal to CPC 5=dead) were documented. Temperatures are presented as median and the range from the first to the third quartile.
RESULTS: Nasopharyngeal cooling for 1h reduced tympanic temperature by median 2.3 (1.6; 3.0) degrees C, core temperature by 1.1 (0.7; 1.5) degrees C. Nasal discoloration occurred during the procedure in 10 (12%) patients, resolved in 9, and was persistent in 1 (1%). Epistaxis was observed in 2 (2%) patients. Periorbital gas emphysema occurred in 1 (1%) patient and resolved spontaneously. Thirty-four of 84 patients (40%) patients survived, 26/34 with favorable neurological outcome (CPC of 1-2) at discharge.
CONCLUSIONS: Nasopharyngeal evaporative cooling used for 1h in primary cardiac arrest survivors is feasible and safe at flow rates of 40-50L/min in a hospital setting.
Safety and feasibility of nasopharyngeal evaporative cooling in the emergency department setting in survivors of cardiac arrest
Resuscitation. 2010 Aug;81(8):943-9

EZ-IO in pre-hospital care

French pre-hospital physicians liked the EZ-IO intraosseous drill, using it for drugs (including rapid sequence intubation drugs) and fluids in the pre-hospital setting. There was a very high insertion success rate.
OBJECTIVE: Intraosseous access is a rapid and safe alternative when peripheral vascular access is difficult. Our aim was to assess the safety and efficacy of a semi-automatic intraosseous infusion device (EZ-IO) when using a management algorithm for difficult vascular access in an out-of-hospital setting.
METHODS: This was a one-year prospective, observational study by mobile intensive care units. After staff training in the use of the EZ-IO device and provision of a management algorithm for difficult vascular access, all vehicles were equipped with the device. We determined device success rate and ease of use, resuscitation fluid volume and drugs administered by the intraosseous route, and complications at insertion site.

RESULTS: A total of 4666 patients required vascular access. The EZ-IO device was used in 30 cardiac arrest patients (25 adults; 5 children) and 9 adults with spontaneous cardiac activity. The success rate for first insertion was 84%. Overall success rate (max. 2 attempts) was 97%. The device was used for fluid resuscitation in 16 patients (mean volume: 680ml), adrenaline administration in 24 patients, and rapid sequence induction in 2 patients. There was only one local complication (transient local inflammation).
CONCLUSIONS: On implementation of an algorithm for the management of difficult vascular access, the EZ-IO device proved safe and highly effective in both adult and paediatric patients in an out-of-hospital emergency setting. It is a suitable device for consideration as a first-line option for difficult vascular access in this setting.
Efficacy and safety of the EZ-IOTM intraosseous device: Out-of-hospital implementation of a management algorithm for difficult vascular access
Resuscitation. 2011 Jan;82(1):126-9

Limits on resuscitative thoractomy in ED

Eighteen trauma centers contributed ED resuscitative thoracotomy data to a study that commenced enrollment in January 2003. During the ensuing 6 years, 56 patients survived to hospital discharge. Mean age was 31.3; the youngest was a 15-year-old female and the oldest was a 64-year-old male; 93% were male. Injury mechanism was stab wound (SW) in 30 patients, gunshot wound (GSW) in 21 patients, and blunt trauma in 5 patients.
The most common injury was a SW to a ventricle (n =17), accounting for 30% of survivors, followed by a GSW to the lung (n =9) in 16%. There were five survivors (9%) after blunt trauma. Two patients were revived with isolated head trauma who had deteriorated from extensive hemorrhage, one from an open blunt skull fracture (who had 5 minutes of prehospital CPR and left the hospital neurologically intact.) and the other from SWs to the scalp. Two patients also survived with isolated neck injuries: a SW to the vertebral artery and a GSW to the internal carotid artery.
34% of survivors underwent prehospital CPR. Corroborating the reported duration of CPR, the mean base deficit (BD) was 23.3 mequiv/L (range, 14–32 mequiv/L) in those undergoing CPR >5 minutes. In the SW group, the duration was 2 minutes to 10 minutes; the sole survivor after 10 minutes had ventricular wounds with pericardial tamponade. In the GSW group, prehospital CPR was from 1 minute to 15 minutes. The only patient surviving with 15 minutes of CPR also had a ventricular wound with pericardial tamponade but had a moderate neurologic deficit at discharge. In the blunt group, CPR ranged from 3 minutes to 9 minutes; the survivor with 9 minutes of CPR had an atrial rupture with pericardial tamponade.
Seven patients survived with asystole at ED arrival; of significance, all patients had pericardial tamponade. At the time of hospital discharge, three of these patients (43%) had functional neurologic recovery.
The authors state: ‘most recent edition of the ACSCOT advanced trauma life support manual continues to declare “patients sustaining blunt injuries who arrive pulseless but with myocardial electrical activity are not candidates for resuscitative thoracotomy”. But these statements are not congruent with most of the recent literature.

Recommended Limits of Resuscitative Thoracotomy in the ED


BACKGROUND: Since the promulgation of emergency department (ED) thoracotomy >40 years ago, there has been an ongoing search to define when this heroic resuscitative effort is futile. In this era of health care reform, generation of accurate data is imperative for developing patient care guidelines. The purpose of this prospective multicenter study was to identify injury patterns and physiologic profiles at ED arrival that are compatible with survival.
METHODS: Eighteen institutions representing the Western Trauma Association commenced enrollment in January 2003; data were collected prospectively.
RESULTS: During the ensuing 6 years, 56 patients survived to hospital discharge. Mean age was 31.3 years (15-64 years), and 93% were male. As expected, survival was predominant in those with thoracic injuries (77%), followed by abdomen (9%), extremity (7%), neck (4%), and head (4%). The most common injury was a ventricular stab wound (30%), followed by a gunshot wound to the lung (16%); 9% of survivors sustained blunt trauma, 34% underwent prehospital cardiopulmonary resuscitation (CPR), and the presenting base deficit was >25 mequiv/L in 18%. Relevant to futile care, there were survivors of blunt torso injuries with CPR up to 9 minutes and penetrating torso wounds up to 15 minutes. Asystole was documented at ED arrival in seven patients (12%); all these patients had pericardial tamponade and three (43%) had good functional neurologic recovery at hospital discharge.
CONCLUSION: Resuscitative thoracotomy in the ED can be considered futile care when (a) prehospital CPR exceeds 10 minutes after blunt trauma without a response, (b) prehospital CPR exceeds 15 minutes after penetrating trauma without a response, and (c) asystole is the presenting rhythm and there is no pericardial tamponade.
Defining the Limits of Resuscitative Emergency Department Thoracotomy: A Contemporary Western Trauma Association Perspective
J Trauma. 2011 Feb;70(2):334-339.

Risk factors for cervical spine injury

Data from the Crash Injury Research Engineering Network (CIREN) database were analysed to identify epidemiologic and biomechanical risk factors for  cervical spinal cord and spinal column injuries. They showed:

  • Older case occupants are at an increased risk of cervical spine injury (CSI)
  • Rollover crashes and severe crashes led to a much higher risk of CSI than other types and severity of MVCs
  • Seat belt use is very effective in preventing CSI
  • Airbag deployment may increase the risk of occupants sustaining a CSI

BACKGROUND: : Motor vehicle collisions (MVCs) are the leading cause of spine and spinal cord injuries in the United States. Traumatic cervical spine injuries (CSIs) result in significant morbidity and mortality. This study was designed to evaluate both the epidemiologic and biomechanical risk factors associated with CSI in MVCs by using a population-based database and to describe occupant and crashes characteristics for a subset of severe crashes in which a CSI was sustained as represented by the Crash Injury Research Engineering Network (CIREN) database.
METHODS: : Prospectively collected CIREN data from the eight centers were used to identify all case occupants between 1996 and November 2009. Case occupants older than 14 years and case vehicles of the four most common vehicle types were included. The National Automotive Sampling System’s Crashworthiness Data System, a probability sample of all police-reported MVCs in the United States, was queried using the same inclusion criteria between 1997 and 2008. Cervical spinal cord and spinal column injuries were identified using Abbreviated Injury Scale (AIS) score codes. Data were abstracted on all case occupants, biomechanical crash characteristics, and injuries sustained. Univariate analysis was performed using a χ analysis. Logistic regression was used to identify significant risk factors in a multivariate analysis to control for confounding associations.
RESULTS: : CSIs were identified in 11.5% of CIREN case occupants. Case occupants aged 65 years or older and those occupants involved in rollover crashes were more likely to sustain a CSI. In univariate analysis of the subset of severe crashes represented by CIREN, the use of airbag and seat belt together (reference) were more protective than seat belt alone (odds ratio [OR] = 1.73, 95% confidence interval [CI] = 1.32-2.27) or the use of neither restraint system (OR = 1.45, 95% CI = 1.02-2.07). The most frequent injury sources in CIREN crashes were roof and its components (24.8%) and noncontact sources (15.5%). In multivariate analysis, age, rollover impact, and airbag-only restraint systems were associated with an increased odds of CSI. Using the population-based National Automotive Sampling System’s Crashworthiness Data System data, 0.35% of occupants sustained a CSI. In univariate analysis, older age was noted to be a significant risk factor for CSI. Airbag-only restraint systems and both rollover and lateral crashes were also identified as risk factors for CSI. In addition, increasing delta v was highly associated with CSIs. In multivariate analysis, similar risk factors were noted. Of all the restraint systems, seat belt use without airbag deployment was found to be the most protective restraint system (OR = 0.29, 95% CI = 0.16-0.50), whereas airbag-only restraint was associated with the highest risk of CSI (OR = 3.54, 95% CI = 2.29-5.46).
CONCLUSIONS: : Despite advances in automotive safety, CSIs sustained in MVC continue to occur too often. Older case occupants are at an increased risk of CSI. Rollover crashes and severe crashes led to a much higher risk of CSI than other types and severity of MVCs. Seat belt use is very effective in preventing CSI, whereas airbag deployment may increase the risk of occupants sustaining a CSI. More protection for older occupants is needed and protection in both rollover and lateral crashes should remain a focus of the automotive industry. The design of airbag restraint systems should be evaluated so that they are not causative of serious injury. In addition, engineers should continue to focus on improving automotive design to minimize the risk of spinal injury to occupants in high severity crashes
Occupant and Crash Characteristics for Case Occupants With Cervical Spine Injuries Sustained in Motor Vehicle Collisions
J Trauma. 2011 Feb;70(2):299-309

Balloon catheters for haemorrhage control

Something I keep up my sleeve (not literally) for managing some life-threatening vascular wounds prior to surgery is the use of a balloon catheter like a foley to tamponade haemorrhage. This paper looks at series of such attempts although they state: “Except for the base of the skull (naso/oropharynx), all catheters were de- ployed in the operating room.“, so not exactly emergency medicine / pre-hospital practice, but a useful reminder that this is an option when going immediately to the operating room isn’t:

BACKGROUND: : Balloon catheter tamponade is a valuable technique for arresting exsanguinating hemorrhage. Indications include (1) inaccessible major vascular injuries, (2) large cardiac injuries, and (3) deep solid organ parenchymal bleeding. Published literature is limited to small case series. The primary goal was to review a recent experience with balloon catheter use for emergency tamponade in a civilian trauma population.
METHODS: : All patients requiring emergency use of a balloon catheter to tamponade exsanguinating hemorrhage (1998-2009) were included. Patient demographics, injury characteristics, technique, and outcomes were analyzed.
RESULTS: : Of the 44 severely injured patients (82% presented with hemodynamic instability; mean base deficit = -20.4) who required balloon catheter tamponade, 23 of the balloons (52%) remained indwelling for more than 6 hours. Overall mortality depended on the site of injury/catheter placement and indwelling time (81% if <6 hours; 52% if ≥6 hours; p < 0.05). Physiologic exhaustion was responsible for 76% of deaths in patients with short-term balloons. Mortality among patients with prolonged balloon catheter placement was 11%, 50%, and 88% for liver, abdominal vascular, and facial/pharyngeal injuries, respectively. Mean indwelling times for iliac, liver, and carotid injuries were 31 hours, 53 hours, and 78 hours, respectively. Overall survival rates were 67% (liver), 67% (extremity vascular), 50% (abdominal vascular), 38% (cardiac), and 8% (face). Techniques included Foley, Fogarty, Blakemore, and/or Penrose drains with concurrent red rubber Robinson catheters. Initial tamponade of bleeding structures was successful in 93% of patients.
CONCLUSIONS: : Balloon catheter tamponade can be used in multiple anatomic regions and for variable patterns of injury to arrest ongoing hemorrhage. Placement for central hepatic gunshot wounds is particularly useful. This technique remains a valuable tool in a surgeon’s armamentarium.
A Decade’s Experience With Balloon Catheter Tamponade for the Emergency Control of Hemorrhage
J Trauma. 2011 Feb;70(2):330-3

ILCOR neonatal cooling guideline

On the basis of the published data to date the Neonatal Task Force of the International Liaison Committee on Resuscitation (ILCOR) made the following recommendation on February 2010 with regard to therapeutic hypothermia:

  • Newly born infants born at term or near-term with evolving moderate to severe hypoxic-ischemic encephalopathy should be offered therapeutic hypothermia.
  • Whole-body cooling and selective head cooling are both appropriate strategies.
  • Cooling should be initiated and conducted in neonatal intensive care facilities using protocols consistent with those used in the randomized clinical trials i.e. commence within 6 h, continue for 72 h and rewarm over at least 4 h.
  • Carefully monitor for known adverse effects of cooling – thrombocytopenia and hypotension.
  • All treated infants should be followed longitudinally.

Therapeutic hypothermia following intrapartum hypoxia-ischemia. An advisory statement from the Neonatal Task Force of the International Liaison Committee on Resuscitation
Resuscitation 2010;81(11):1459-1461

Difficult tube – Easytube

French pre-hospital physicians included the Easytube, which is similar to the Combitube, in their difficult airway algorithm. They describe the insertion method as:
..inserted blindly, the patient’s head must be in neutral position. Manually opening the patient’s mouth and pressing the tongue gently toward the mandible, the tube is inserted parallel to the frontal axis of the patient until the proximal black ring mark is positioned at the level of the incisors. If the EzT is inserted blindly, the tip is likely to be positioned in the esophagus with a probability of more than 95% [3]. Ventilation of the patient should be performed using a colored lumen, and the transparent lumen can then be used to insert a gastric tube or to drain gastric contents.
The authors suggest that the main advantages of the Ezt are: shorter insertion time for Ezt than for ETI, better protection against aspiration than a laryngeal mask and the possibility of blind insertion of the Ezt in patients trapped in a sitting position.
BACKGROUND: Securing the airway in emergency is among the key requirements of appropriate prehospital therapy. The Easytube (Ezt) is a relatively new device, which combines the advantages of both an infraglottic and supraglottic airway.
AIMS: Our goal was to evaluate the effectiveness and the safety of use of Ezt by emergency physicians in case of difficult airway management in a prehospital setting with minimal training.

METHODS: We performed a prospective multi-centre observational study of patients requiring airway management conducted in prehospital emergency medicine in France by 3 French mobile intensive care units from October 2007 to October 2008.
RESULTS: Data were available for 239 patients who needed airway management. Two groups were individualized: the “easy airway management” group (225 patients; 94%) and the “difficult airway management” group (14 patients; 6%). All patients had a successful airway management. The Ezt was used in eight men and six women; mean age was 64 years. It was used for ventilation for a maximum of 150 min and the mean time was 65 min. It was positioned successfully at first attempt, except for two patients, one needed an adjustment because of an air leak, and in the other patient the Ezt was replaced due to complete obstruction of the Ezt during bronchial suction.
CONCLUSION: The present study shows that emergency physicians in cases of difficult airway management can use the EzT safely and effectively with minimal training. Because of its very high success rate in ventilation, the possibility of blind intubation, the low failure rate after a short training period. It could be introduced in new guidelines to manage difficult airway in prehospital emergency.
The Easytube for airway management in prehospital emergency medicine
Resuscitation. 2010 Nov;81(11):1516-20