Tag Archives: resuscitation

Tympanic monitoring for targeted temperature management

As the authors of this study point out, the reliability of tympanic temperature monitoring is still under debate. Since invasive measures of core temperature employed in the ICU may not be practicable in the pre-hospital setting, it would be helpful to employ a simpler method in the field, particular if we are implementing targeted temperature management post-cardiac arrest. In this small study of ten patients (with 558 temperature measurements) there was a high degree of correlation between tympanic and oesophageal temperature (r=0.95, p<0.0001, 95% CI 0.93 to 0.96) and also between tympanic and bladder temperature (r=0.96, p<0.0001, 95% CI 0.95 to 0.97). This finding is apparently in keeping with results obtained from patients undergoing cardiac surgery.

Objective Prehospital induction of therapeutic hypothermia after cardiac arrest may require temperature monitoring in the field. Tympanic temperature is non-invasive and frequently used in clinical practice. Nevertheless, it has not yet been evaluated in patients undergoing mild therapeutic hypothermia (MTH). Therefore, a prospective observational study was conducted comparing three different sites of temperature monitoring during therapeutic hypothermia.
Methods Ten consecutive patients admitted to our medical intensive care unit after out-of-hospital cardiac arrest were included in this study. During MTH, tympanic temperature was measured using a digital thermometer. Simultaneously, oesophageal and bladder temperatures were recorded in a total of 558 single measurements.
Results Compared with oesophageal temperature, bladder temperature had a bias of 0.019°C (limits of agreement ±0.61°C (2SD)), and tympanic measurement had a bias of 0.021°C (±0.80°C). Correlation analysis revealed a high relationship for tympanic versus oesophageal temperature (r=0.95, p<0.0001) and also for tympanic versus bladder temperature (r=0.96, p<0.0001).
Conclusions That tympanic temperature accurately indicates both oesophageal and bladder temperatures with a very small discrepancy in patients undergoing MTH after cardiac arrest is demonstrated in this study. Although our results were obtained in the hospital setting, these findings may be relevant for the prehospital application of therapeutic hypothermia as well. In this case, tympanic temperature may provide an easy and non-invasive method for temperature monitoring.

Tympanic temperature during therapeutic hypothermia
Emerg Med J. 2011 Jun;28(6):483-5

Hyperkalaemia dogmalysis


One of the things I enjoy most is the dismantling of medical dogma. In his brilliant blog Precious Bodily Fluids, nephrologist Joel Topf reviewed some of the hyperkalaemia literature and offers some of the following pearls:

  • The ECG is insensitive and non-specific as a means of diagnosing (and in particular ruling out) hyperkalaemia (sensitivity of ‘strict’ criteria of symmetrical peaked T waves that resolve on follow up: 18%; sensitivity of any ECG change: 52%).
  • The dangers of calcium treatment for digoxin toxicity-associated hyperkalaemia may be exaggerated and are supported by very weak evidence
  • Sodium bicarbonate does not effectively lower potassium but does lower ionised calcium which can increase the risk of hyperkalaemia-associated dysrhythmia

Read the full blog post here
View Dr Topf’s presentation below:

ACEP policy on PE

The American College of Emergency Physicians has revised its 2003 clinical policy on pulmonary embolism.


 
Among the areas considered is the the role of thrombolytic medication. The policy provides the following recommendations to this question:

What are the indications for thrombolytic therapy in patients with PE?
Level B recommendations
Administer thrombolytic therapy in hemodynamically unstable patients with confirmed PE for whom the benefits of treatment outweigh the risks of life-threatening bleeding complications.*
*In centers with the capability for surgical or mechanical thrombectomy, procedural intervention may be used as an alternative therapy.
Level C recommendations
(1) Consider thrombolytic therapy in hemodynamically unstable patients with a high clinical suspicion for PE for whom the diagnosis of PE cannot be confirmed in a timely manner.
(2) At this time, there is insufficient evidence to make any recommendations regarding use of thrombolytics in any subgroup of hemodynamically stable patients. Thrombolytics have been demonstrated to result in faster improvements in right ventricular function and pulmonary perfusion, but these benefits have not translated to improvements in mortality.

The document contains a detailed appraisal of the literature to date on benefits and harms from thrombolysis. Of interest is the Pulmonary Embolism Severity Index (PESI) – a scoring system that appears to reliably predict mortality and thus has the potential to assist physicians in making risk-benefit decisions when considering administration of thrombolytics. The full text of the policy, which covers far more than just thrombolysis, can be found by following the link below.
Critical Issues in the Evaluation and Management of Adult Patients Presenting to the Emergency Department With Suspected Pulmonary Embolism
Annals of Emergency Medicine 2011 June 57(6):628-652 – Free Full Text

Drugs in cardiac arrest – guess what works?

Just like epinephrine (adrenaline), amiodarone does not increase survival to hospital discharge in cardiac arrest patients. I doubt his will deter the people in the resuscitation room with their stopwatches from handing me these drugs and telling me I ought to be giving them though.

Amiodarone - a load of balls

 

AIMS: In adult cardiac arrest, antiarrhythmic drugs are frequently utilized in acute management and legions of medical providers have memorized the dosage and timing of administration. However, data supporting their use is limited and is the focus of this comprehensive review.

METHODS: Databases including PubMed, Cochrane Library (including Cochrane database for systematic reviews and Cochrane Central Register of Controlled Trials), Embase, and AHA EndNote Master Library were systematically searched. Further references were gathered from cross-references from articles and reviews as well as forward search using SCOPUS and Google scholar. The inclusion criteria for this review included human studies of adult cardiac arrest and anti-arrhythmic agents, peer-review. Excluded were review articles, case series and case reports.

RESULTS: Of 185 articles found, only 25 studies met the inclusion criteria for further review. Of these, 9 were randomised controlled trials. Nearly all trials solely evaluated Ventricular Tachycardia (VT) and Ventricular Fibrillation (VF), and excluded Pulseless Electrical Activity (PEA) and asystole. In VT/VF patients, amiodarone improved survival to hospital admission, but not to hospital discharge when compared to lidocaine in two randomized controlled trials.

CONCLUSION: Amiodarone may be considered for those who have refractory VT/VF, defined as VT/VF not terminated by defibrillation, or VT/VF recurrence in out of hospital cardiac arrest or in-hospital cardiac arrest. There is inadequate evidence to support or refute the use of lidocaine and other antiarrythmic agents in the same settings.

The use of antiarrhythmic drugs for adult cardiac arrest: A systematic review
Resuscitation. 2011 Jun;82(6):665-70

Single bag for adults and kids

A nice idea – using a single adult self-inflating bag for the resuscitation of adult and paediatric patients, marked to identify compression points that deliver specific tidal volume ranges. Might be useful in situations where equipment needs to be minimised, such as military or pre-hospital settings.

AIM: To overcome limitations of inaccurate tidal volume (TV) delivery by conventional selfinflating paediatric and adult bags during paediatric and adolescent resuscitation, we designed a novel target volume marked bag (TVMB) with four compression points marked on an adult bag surface. The aim of this study was to evaluate the TVMB in delivering preset TV.

METHODS: Fifty-three subjects (28 doctors, 17 nurses, 8 paramedics) participated in this simulation trial. TVMB, paediatric bag and adult bag were connected to a gas flow analyser for measuring TV and peak inspiratory pressure (PIP). In a random cross-over setting, participants delivered 10 ventilations using the adult bag, paediatric bag or TVMB in each of four target volume ranges (100-200ml, 200-300ml, 300-400ml, 400-500ml). We compared TV and PIP for the adult bag, paediatric bag and TVMB in each subject.

RESULTS: Compared with the paediatric bag, TVMB showed higher rates of accurate TV delivery in the 200-300ml target volume range (87-90% versus 32-35%; p<0.05). Compared with the adult bag, TVMB showed higher rates of accurate TV delivery in all target volume ranges (75-90% versus 45-50%; p<0.05). The frequency of too high or low TV delivery was higher with the adult bag than TVMB (20-30% versus 0-5%; p<0.05). There was no significant difference in PIP between the paediatric bag and TVMB (within 5cm H(2)O; p<0.05).

CONCLUSIONS: TVMB could deliver accurate TV in various target volume ranges for paediatric and adolescent resuscitation.

Resuscitation. 2011 Jun;82(6):749-54

Fluid Bolus in African Children with Severe Infection

Much discussion has already taken place in the blogosphere about the FEAST study of fluid resuscitation in septic children. Although a well conducted study, its external validity to Western populations is dubious, particularly in view of the proportion of malaria in the cohorts studied.

In the words of my emergency physician colleague Dr Fiona Rae from Wrexham, UK:

“Interesting. As they say, a completely different population in a resource limited setting so it doesn’t translate to UK practice. Majority of these children had malaria and if I read correctly 32% had Hb < 5g/dl. Also 20-40mls/kg is quite a lot of fluid these days as an initial bolus other than in the sort of severely shocked patients that they seemed to exclude. Their overall mortality also seems to be lower than expected for this population.

If you work in an environment without ITU and a high incidence of malaria then its a useful study. They are not the sort of children I see in my resus room with shock though.”
Nicely put Fi!
You can also read an analysis of this study on Dr G’s blog – where you can find other posts on critical care and emergency medicine.

Background
The role of fluid resuscitation in the treatment of children with shock and life-threatening infections who live in resource-limited settings is not established.
Methods
We randomly assigned children with severe febrile illness and impaired perfusion to receive boluses of 20 to 40 ml of 5% albumin solution (albumin-bolus group) or 0.9% saline solution (saline-bolus group) per kilogram of body weight or no bolus (control group) at the time of admission to a hospital in Uganda, Kenya, or Tanzania (stratum A); children with severe hypotension were randomly assigned to one of the bolus groups only (stratum B). Children with malnutrition or gastroenteritis were excluded. The primary end point was 48-hour mortality; secondary end points included pulmonary edema, increased intracranial pressure, and mortality or neurologic sequelae at 4 weeks.
Results
The data and safety monitoring committee recommended halting recruitment after 3141 of the projected 3600 children in stratum A were enrolled. Malaria status (57% overall) and clinical severity were similar across groups. The 48-hour mortality was 10.6% (111 of 1050 children), 10.5% (110 of 1047 children), and 7.3% (76 of 1044 children) in the albumin-bolus, saline-bolus, and control groups, respectively (relative risk for saline bolus vs. control, 1.44; 95% confidence interval [CI], 1.09 to 1.90; P=0.01; relative risk for albumin bolus vs. saline bolus, 1.01; 95% CI, 0.78 to 1.29; P=0.96; and relative risk for any bolus vs. control, 1.45; 95% CI, 1.13 to 1.86; P=0.003). The 4-week mortality was 12.2%, 12.0%, and 8.7% in the three groups, respectively (P=0.004 for the comparison of bolus with control). Neurologic sequelae occurred in 2.2%, 1.9%, and 2.0% of the children in the respective groups (P=0.92), and pulmonary edema or increased intracranial pressure occurred in 2.6%, 2.2%, and 1.7% (P=0.17), respectively. In stratum B, 69% of the children (9 of 13) in the albumin-bolus group and 56% (9 of 16) in the saline-bolus group died (P=0.45). The results were consistent across centers and across subgroups according to the severity of shock and status with respect to malaria, coma, sepsis, acidosis, and severe anemia.
Conclusions
Fluid boluses significantly increased 48-hour mortality in critically ill children with impaired perfusion in these resource-limited settings in Africa.

Mortality after Fluid Bolus in African Children with Severe Infection
NEJM May 26, 2011 Full text available

Cardiac arrest drugs and pupils

Although not predictive immediately post-cardiac arrest in the emergency department, dilated unreactive pupils two or three days later on the ICU may indicate a hopeless prognosis. We know from our experience with adrenaline (epinephrine) infusions that this drug does not prevent pupils from reacting to light, but what about atropine?

A letter by Dr Sophie MacDougall-Davis in Resuscitation describes a 66 year old male patient admitted to the ICU after an intraoperative PEA arrest during which he received 3 mg intravenous atropine. Post arrest and post anaesthesia he was awake with no neurological deficit, but eight hours after the cardiac arrest his pupils remained fixed and dilated, and were dilated with only a very slight reaction the next morning and remained sluggish at forty-eight hours, normalising at seventy-two hours. A possible reason for its prolonged action may be uptake of atropine from the plasma into the aqueous humor of the eye, followed by its slow release.
Dr MacDougall-Davis cautions:

When assessing pupils in comatose cardiac arrest survivors, the potential for atropine to have a prolonged effect on pupil size and reactivity should be considered.

Atropine, fixed dilated pupils and prognostication following cardiac arrest
Resuscitation. 2011 Feb;82(2):232

Two hands on the jaw for mask ventilation

Elective surgery patients were anaesthetised with propofol with or without fentanyl and had an oropharyngeal airway placed. They were ventilated with pressure control ventilation via facemask held with a single handed traditional ‘EC clamp’ grip and with a two-handed jaw thrust, and compared. The order in which these two techniques were trialled was randomised. All breaths were delivered with a peak pressure of 15 cm H2O, an inspiratory-to-expiratory ratio of 1:1, at a frequency of 15 breaths per minute. Ventilation was more effective with the two handed technique.
Using a self-inflating bag for resuscitation, this would translate to a two-person technique. Of note in methodology however was use of a ‘standard pillow’ and some emphasis on head extension. Perhaps ventilation would have been more effective with either technique if they had applied the golden rule of ear-to-sternal-notch positioning: a must for effective mask ventilation and successful laryngoscopy.

BACKGROUND: Mask ventilation is considered a “basic” skill for airway management. A one-handed “EC-clamp” technique is most often used after induction of anesthesia with a two-handed jaw-thrust technique reserved for difficult cases. Our aim was to directly compare both techniques with the primary outcome of air exchange in the lungs.
METHODS: Forty-two elective surgical patients were mask-ventilated after induction of anesthesia by using a one-handed “EC-clamp” technique and a two-handed jaw-thrust technique during pressure-control ventilation in randomized, crossover fashion. When unresponsive to a jaw thrust, expired tidal volumes were recorded from the expiratory limb of the anesthesia machine each for five consecutive breaths. Inadequate mask ventilation and dead-space ventilation were defined as an average tidal volume less than 4 ml/kg predicted body weight or less than 150 ml/breath, respectively. Differences in minute ventilation and tidal volume between techniques were assessed with the use of a mixed-effects model.
RESULTS: Patients were (mean ± SD) 56 ± 18 yr old with a body mass index of 30 ± 7.1 kg/m. Minute ventilation was 6.32 ± 3.24 l/min with one hand and 7.95 ± 2.70 l/min with two hands. The tidal volume was 6.80 ± 3.10 ml/kg predicted body weight with one hand and 8.60 ± 2.31 ml/kg predicted body weight with two hands. Improvement with two hands was independent of the order used. Inadequate or dead-space ventilation occurred more frequently during use of the one-handed compared with the two-handed technique (14 vs. 5%; P = 0.013).
CONCLUSION: A two-handed jaw-thrust mask technique improves upper airway patency as measured by greater tidal volumes during pressure-controlled ventilation than a one-handed “EC-clamp” technique in the unconscious apneic person.

A Two-handed Jaw-thrust Technique Is Superior to the One-handed “EC-clamp” Technique for Mask Ventilation in the Apneic Unconscious Person
Anesthesiology. 2010 Oct;113(4):873-9

ECLS on Japanese, in Japanese

A review of extracorporeal life support for out-of-hospital cardiac arrest was undertaken, looking specifically at studies published in the Japanese literature. The abstract is shown below. Based on these findings, inclusion criteria for a multicentre, prospective non-randomised cohort study were established. The ‘SAVE-J: Study of advanced life support for ventricular fibrillation with extracorporeal circulation in Japan’ was launched and has been ongoing since October 2008 to compare the proportion of patients with a favourable neurological outcome by intention-to-treat in an ECPR group with a non-ECPR group. Inclusion criteria for this new study are:

  1. shockable rhythm on the initial ECG
  2. cardiac arrest on arrival at hospital regardless of the presence of recovery of spontaneous circulation before arrival
  3. arrival at hospital within 45 min of the call for an ambulance or cardiac arrest;
  4. cardiac arrest remaining for more than 15 min after arrival at hospital.

I look forward to seeing the results SAVE-J. If you wish to read more, you can check out the SAVE-J study website.

AIM: Although favourable outcomes in patients receiving extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest have been frequently reported in Japanese journals since the late 1980s, there has been no meta-analysis of ECPR in Japan. This study reviewed and analysed all previous studies in Japan to clarify the survival rate of patients receiving ECPR.
MATERIAL AND METHODS: Case reports, case series and abstracts of scientific meetings of ECPR for out-of-hospital cardiac arrest written in Japanese between 1983 and 2008 were collected. The characteristics and outcomes of patients were investigated, and the influence of publication bias of the case-series studies was examined by the funnel-plot method.
RESULTS: There were 1282 out-of-hospital cardiac arrest patients, who received ECPR in 105 reports during the period. The survival rate at discharge given for 516 cases was 26.7±1.4%. The funnel plot presented the relationship between the number of cases of each report and the survival rate at discharge as the reverse-funnel type that centred on the average survival rate. In-depth review of 139 cases found that the rates of good recovery, mild disability, severe disability, vegetative state, death at hospital discharge and non-recorded in all cases were 48.2%, 2.9%, 2.2%, 2.9%, 37.4% and 6.4%, respectively.
CONCLUSIONS: Based on the results of previous reports with low publication bias in Japan, ECPR appears to provide a higher survival rate with excellent neurological outcome in patients with out-of-hospital cardiac arrest.

Extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest: a review of the Japanese literature
Resuscitation. 2011 Jan;82(1):10-4

Which cardiac arrest survivors have a positive angio?

A retrospective study of out-of-hospital cardiac arrest patients attended by a French pre-hospital system was performed to assess the predictive factors for positive coronary angiography.

OBJECTIVES: Coronary angiography is often performed in survivors of out-of-hospital cardiac arrest, but little is known about the factors predictive of a positive coronary angiography. Our aim was to determine these factors.
METHODS: In this 7-year retrospective study (January 2000-December 2006) conducted by a French out-of-hospital emergency medical unit, data were collected according to Utstein style guidelines on all out-of-hospital cardiac arrest patients with suspected coronary disease who recovered spontaneous cardiac activity and underwent early coronary angiography. Coronary angiography was considered positive if a lesion resulting in more than a 50% reduction in luminal diameter was observed or if there was a thrombus at an occlusion site.
RESULTS: Among the 4621 patients from whom data were collected, 445 were successfully resuscitated and admitted to hospital. Of these, 133 were taken directly to the coronary angiography unit, 95 (71%) had at least one significant lesion, 71 (53%) underwent a percutaneous coronary intervention, and 30 survived [23%, 95% confidence interval (CI): 16-30]. According to multivariate analysis, the factors predictive of a positive coronary angiography were a history of diabetes [odds ratio (OR): 7.1, 95% CI: 1.4-36], ST segment depression on the out-of-hospital ECG (OR: 5.4, 95% CI: 1.1-27.8), a history of coronary disease (OR: 5.3, 95% CI: 1.4-20.1), cardiac arrest in a public place (OR: 3.7, 95% CI: 1.3-10.7), and ventricular fibrillation or ventricular tachycardia as initial rhythm (OR: 3.1, 95% CI: 1.1-8.6).
CONCLUSION: Among the factors identified, diabetes and a history of coronary artery were strong predictors for a positive coronary angiography, whereas ST segment elevation was not as predictive as expected.

Predictive factors for positive coronary angiography in out-of-hospital cardiac arrest patients
Eur J Emerg Med. 2011 Apr;18(2):73-6