Category Archives: All Updates

Acute Med, All Updates, Resus

TIA workup renders ABCD2 unhelpful

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ABCD2 is recommended to stratify the risk of stroke in patients presenting to the ED with TIA symptoms. In some centres this is used to differentiate those that need to be admitted for further evaluation and treatment from those that can be followed up in the outpatient setting. A recent study showed that if a detailed work up was done in the ED on all TIA patients (followed by appropriate intervention), the ABCD2 score did not predict adverse outcomes, which were lower in this cohort than in the original ABCD2 cohort.

STUDY OBJECTIVE: We study the incremental value of the ABCD2 score in predicting short-term risk of ischemic stroke after thorough emergency department (ED) evaluation of transient ischemic attack.
METHODS: This was a prospective observational study of consecutive patients presenting to the ED with a transient ischemic attack. Patients underwent a full ED evaluation, including central nervous system and carotid artery imaging, after which ABCD2 scores and risk category were assigned. We evaluated correlations between risk categories and occurrence of subsequent ischemic stroke at 7 and 90 days.
RESULTS: The cohort consisted of 637 patients (47% women; mean age 73 years; SD 13 years). There were 15 strokes within 90 days after the index transient ischemic attack. At 7 days, the rate of stroke according to ABCD2 category in our cohort was 1.1% in the low-risk group, 0.3% in the intermediate-risk group, and 2.7% in the high-risk group. At 90 days, the rate of stroke in our ED cohort was 2.1% in the low-risk group, 2.1% in the intermediate-risk group, and 3.6% in the high-risk group. There was no relationship between ABCD2 score at presentation and subsequent stroke after transient ischemic attack at 7 or 90 days.
CONCLUSION: The ABCD2 score did not add incremental value beyond an ED evaluation that includes central nervous system and carotid artery imaging in the ability to risk-stratify patients with transient ischemic attack in our cohort. Practice approaches that include brain and carotid artery imaging do not benefit by the incremental addition of the ABCD2 score. In this population of transient ischemic attack patients, selected by emergency physicians for a rapid ED-based outpatient protocol that included early carotid imaging and treatment when appropriate, the rate of stroke was independent of ABCD2 stratification.

An Assessment of the Incremental Value of the ABCD2 Score in the Emergency Department Evaluation of Transient Ischemic Attack
Ann Emerg Med. 2011 Jan;57(1):46-51

All Updates, Resus

Midazolam smoothens adult ketamine sedation

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In adults undergoing procedural sedation with ketamine, 0.03 mg/kg IV midazolam reduced recovery agitation compared with placebo.

You don’t need this. Just give the midazolam.


STUDY OBJECTIVE: We assess whether midazolam reduces recovery agitation after ketamine administration in adult emergency department (ED) patients and also compared the incidence of adverse events (recovery agitation, respiratory, and nausea/vomiting) by the intravenous (IV) versus intramuscular (IM) route.

METHODS: This prospective, double-blind, placebo-controlled, 2×2 factorial trial randomized consecutive ED patients aged 18 to 50 years to 4 groups: receiving either 0.03 mg/kg IV midazolam or placebo, and with ketamine administered either 1.5 mg/kg IV or 4 mg/kg IM. Adverse events and sedation characteristics were recorded.

RESULTS: Of the 182 subjects, recovery agitation was less common in the midazolam cohorts (8% versus 25%; difference 17%; 95% confidence interval [CI] 6% to 28%; number needed to treat 6). When IV versus IM routes were compared, the incidences of adverse events were similar (recovery agitation 13% versus 17%, difference 4%, 95% CI -8% to 16%; respiratory events 0% versus 0%, difference 0%, 95% CI -2% to 2%; nausea/vomiting 28% versus 34%, difference 6%, 95% CI -8% to 20%).

CONCLUSION: Coadministered midazolam significantly reduces the incidence of recovery agitation after ketamine procedural sedation and analgesia in ED adults (number needed to treat 6). Adverse events occur at similar frequency by the IV or IM routes.

Ketamine with and without midazolam for emergency department sedation in adults: a randomized controlled trial
Ann Emerg Med. 2011 Feb;57(2):109-114

All Updates, ICU, PHARM, Resus

Pre-hospital RSI and single use blades

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Single-use metal laryngoscope blades were compared in a randomised trial in the pre-hospital setting by French SAMU physicians. First-pass intubation success (defined as one advancement of the tube in the direction of the glottis during direct laryngoscopy) was similar between conventional and disposable metal blades.

A French doctor (not involved in the study)

STUDY OBJECTIVE: Emergency tracheal intubation is reported to be more difficult with single-use plastic than with reusable metal laryngoscope blades in both inhospital and out-of-hospital settings. Single-use metal blades have been developed but have not been compared with conventional metal blades. This controlled trial compares the efficacy and safety of single-use metal blades with reusable metal blades in out-of-hospital emergency tracheal intubation.
METHODS: This randomized controlled trial was carried out in France with out-of-hospital emergency medical units (Services de Médecine d’Urgence et de Réanimation). This was a multicenter prospective noninferiority randomized controlled trial in adult out-of-hospital patients requiring emergency tracheal intubation. Patients were randomly assigned to either single-use or reusable metal laryngoscope blades and intubated by a senior physician or a nurse anesthetist. The primary outcome was first-pass intubation success. Secondary outcomes were incidence of difficult intubation, need for alternate airway devices, and early intubation-related complications (esophageal intubation, mainstem intubation, vomiting, pulmonary aspiration, dental trauma, bronchospasm or laryngospasm, ventricular tachycardia, arterial desaturation, hypotension, or cardiac arrest).
RESULTS: The study included 817 patients, including 409 intubated with single-use blades and 408 with a reusable blade. First-pass intubation success was similar in both groups: 292 (71.4%) for single-use blades, 290 (71.1%) for reusable blades. The 95% confidence interval (CI) for the difference in treatments (0.3%; 95% CI -5.9% to 6.5%) did not include the prespecified inferiority margin of -7%. There was no difference in rate of difficult intubation (difference 3%; 95% CI -7% to 2%), need for alternate airway (difference 4%; 95% CI -8% to 1%), or early complication rate (difference 3%; 95% CI -3% to 8%).
CONCLUSION: First-pass out-of-hospital tracheal intubation success with single-use metal laryngoscopy blades was noninferior to first-pass success with reusable metal laryngoscope blades.

Out-of-Hospital Tracheal Intubation With Single-Use Versus Reusable Metal Laryngoscope Blades: A Multicenter Randomized Controlled Trial
Ann Emerg Med. 2011 Mar;57(3):225-31

Acute Med, All Updates, PHARM

Delayed door-to-balloon even with helicopters

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For a whole bunch of reasons, patients with ST-elevation myocardial infarction who undergo interhospital transfer for primary percutaneous coronary intervention may not meet the required 90 minute door-to-balloon time. In a new study of patients transferred by helicopter, only 3% of STEMI patients transferred for reperfusion met the 90-minute goal. Should this result in an increase in the use of fibrinolysis at non–percutaneous coronary intervention hospitals?

Opportunity for gratuitous helicopter shot never knowingly declined

STUDY OBJECTIVE: Early reperfusion portends better outcomes for ST-segment elevation myocardial infarction (STEMI) patients. This investigation estimates the proportions of STEMI patients transported by a hospital-based helicopter emergency medical services (EMS) system who meet the goals of 90-minute door-to-balloon time for percutaneous coronary intervention or 30-minute door-to-needle time for fibrinolysis.
METHODS: This was a multicenter, retrospective chart review of STEMI patients flown by a hospital-based helicopter service in 2007. Included patients were transferred from an emergency department (ED) to a cardiac catheterization laboratory for primary or rescue percutaneous coronary intervention. Out-of-hospital, ED, and inpatient records were reviewed to determine door-to-balloon time and door-to-needle time. Data were abstracted with a priori definitions and criteria.
RESULTS: There were 179 subjects from 16 referring and 6 receiving hospitals. Mean age was 58 years, 68% were men, and 86% were white. One hundred forty subjects were transferred for primary percutaneous coronary intervention, of whom 29 had no intervention during catheterization. For subjects with intervention, door-to-balloon time exceeded 90 minutes in 107 of 111 cases (97%). Median door-to-balloon time was 131 minutes (interquartile range 114 to 158 minutes). Thirty-nine subjects (21%) received fibrinolytics before transfer, and 19 of 39 (49%) received fibrinolytics within 30 minutes. Median door-to-needle time was 31 minutes (interquartile range 23 to 45 minutes).
CONCLUSION: In this study, STEMI patients presenting to non-percutaneous coronary intervention facilities who are transferred to a percutaneous coronary intervention-capable hospital by helicopter EMS do not commonly receive fibrinolysis and rarely achieve percutaneous coronary intervention within 90 minutes. In similar settings, primary fibrinolysis should be considered while strategies to reduce the time required for subsequent interventional care are explored.

Reperfusion Is Delayed Beyond Guideline Recommendations in Patients Requiring Interhospital Helicopter Transfer for Treatment of ST-segment Elevation Myocardial Infarction.
Ann Emerg Med. 2011 Mar;57(3):213-220

Acute Med, All Updates, ICU

H1N1 or CAP?

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A scoring system composed of clinical, radiological, and laboratory variables purports to distinguish H1N1 influenza virus infection from community acquired pneumonia1. An accompanying editorial2 suggests that while further validation is required, the most useful application of the score might be in those with a score of 0 or 1 (out of 5), in whom the the high negative predictive value might safely avoid inpatient isolation and neuraminidase inhibitor treatment in the under-65s.

Background Early identification of patients with H1N1 influenza-related pneumonia is desirable for the early instigation of antiviral agents. A study was undertaken to investigate whether adults admitted to hospital with H1N1 influenza-related pneumonia could be distinguished clinically from patients with non-H1N1 community-acquired pneumonia (CAP).
Methods Between May 2009 and January 2010, clinical and epidemiological data of patients with confirmed H1N1 influenza infection admitted to 75 hospitals in the UK were collected by the Influenza Clinical Information Network (FLU-CIN). Adults with H1N1 influenza-related pneumonia were identified and compared with a prospective study cohort of adults with CAP hospitalised between September 2008 and June 2010, excluding those admitted during the period of the pandemic.
Results Of 1046 adults with confirmed H1N1 influenza infection in the FLU-CIN cohort, 254 (25%) had H1N1 influenza-related pneumonia on admission to hospital. In-hospital mortality of these patients was 11.4% compared with 14.0% in patients with inter-pandemic CAP (n=648). A multivariate logistic regression model was generated by assigning one point for each of five clinical criteria: age ≤65 years, mental orientation, temperature ≥38°C, leucocyte count ≤12×10(9)/l and bilateral radiographic consolidation. A score of 4 or 5 predicted H1N1 influenza-related pneumonia with a positive likelihood ratio of 9.0. A score of 0 or 1 had a positive likelihood ratio of 75.7 for excluding it.
Conclusion There are substantial clinical differences between H1N1 influenza-related pneumonia and inter-pandemic CAP. A model based on five simple clinical criteria enables the early identification of adults admitted with H1N1 influenza-related pneumonia.

1. Clinical and laboratory features distinguishing pandemic H1N1 influenza-related pneumonia from interpandemic community-acquired pneumonia in adults
Thorax. 2011 March; 66(3): 247–252 Free Full Text
2. Predicting the unpredictable: is it possible clinically to separate H1N1 from non-H1N1 community-acquired pneumonia?
Thorax. 2011 Mar;66(3):187-8

All Updates, ICU, Resus

More on Rocuronium (and Sugammadex)

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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

All Updates, ICU, Resus

Neuromuscular blockade facilitates mask ventilation

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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.‘
ABSTRACT
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

Acute Med, All Updates, ICU, Resus

Nasal cooling method

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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

All Updates, PHARM, Resus

EZ-IO in pre-hospital care

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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