Tag Archives: ACLS

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

In V.Fib and talking to you!

Some patients with severe refractory heart failure are kept alive thanks to implantable pumps such as the left ventricular assist device (LVAD). Many emergency physicians are likely to be unfamiliar with these but could encounter patients who have them. One particular peculiarity is that latter generation devices maintain non-pulsatile flow and provide or assist cardiac output independent of cardiac rhythm. In extreme situations patients can have life-sustaining cardiac outputs without palpable pulses or even audible heart sounds.

Click on image for Wikipedia article

A great example of how weird this can get is provided by a case of a 66 year male with an LVAD (HeartMate II (Thoratec Corporation)) who presented due to spontaneous discharge of his internal cardioverter-defibrillator (ICD). He was alert but had no pulses, and no detectable blood pressure using both a manual sphygmomanometer and an automated non-invasive blood pressure device. His 12 lead showed ventricular fibrillation. An invasive blood pressure showed a mean arterial pressure (mAP) of 80 mmHg. Several hours later his VF was successfully terminated and his mAP remained 80 mmHg
Some interesting points made by the authors include:

  • CPR was unnecessary in this guy but in cases of severe RV dysfunction it might need to be done to provide flow into the LV.
  • A danger of CPR in patients with an LVAD is the risk of damage to the device or ventricular rupture

LVAD use is significantly increasing so we can expect to encounter more episodes of previously impossible presentations to our emergency departments.

ABSTRACT
Optimal medical treatment, cardiac resynchronization, and the use of an implantable cardioverter defibrillator are established therapies of severe congestive heart failure. In refractory cases, left ventricular assist devices are more and more used not only as bridging to cardiac transplantation but also as destination therapy. Ventricular arrhythmias may represent a life-threatening condition and often result in clinical deterioration in patients with congestive heart failure. We report a case of asymptomatic sustained ventricular fibrillation with preserved hemodynamics caused by a nonpulsatile left ventricular assist device. Consecutive adequate but unsuccessful discharges of the implantable cardioverter defibrillator were the only sign of the usually fatal arrhythmia, prompting the patient to consult emergency services. Electrolyte supplementation and initiation of therapy with amiodarone followed by external defibrillation resulted in successful restoration of a stable cardiac rhythm after 3.5 hours.

Asymptomatic Sustained Ventricular Fibrillation in a Patient With Left Ventricular Assist Device
Ann Emerg Med. 2011 Jan;57(1):25-8.

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

Pre-hospital Echo

Pre-hospital physicians in Germany performed basic echo on patients with symptoms either of profound hypotension and/or severe dyspnoea/tachypnoea where judged by the physician to be in a ‘peri-resuscitation’ state, and on patients undergoing CPR. Features noted were; cardiac motion (present or absent), ventricular function (normal, moderately impaired, severely impaired, absent), right ventricular dilatation or pericardial collection.
A few interesting findings to note:

  • In almost all patients an interpretable view was achieved; in the CPR patients, the subcostal view was best
  • In PEA patients, there was a difference in survival to admission (to discharge isn’t documented) between those with and without sonographically evident cardiac wall motion (21/38 = 55% vs 1/13 = 8%)
  • In ‘suspected asystole’, some patients had sonographically evident cardiac wall motion, and 9/37 (24%) of these survived to hospital admission vs 4/37 (11%) with no wall motion. On this point, the authors note: ‘The ECG performance and interpretation were by experienced practitioners, and this therefore raises questions regarding the accuracy of an ECG diagnosis of asystole in the pre-hospital setting‘.

Purpose of the study: Focused ultrasound is increasingly used in the emergency setting, with an ALS- compliant focused echocardiography algorithm proposed as an adjunct in peri-resuscitation care (FEEL). The purpose of this study was to evaluate the feasibility of FEEL in pre-hospital resuscitation, the incidence of potentially treatable conditions detected, and the influence on patient management.
Patients, materials and methods: A prospective observational study in a pre-hospital emergency setting in patients actively undergoing cardio-pulmonary resuscitation or in a shock state. The FEEL protocol was applied by trained emergency doctors, following which a standardised report sheet was completed, including echo findings and any echo-directed change in management. These reports were then analysed independently.
Results: A total of 230 patients were included, with 204 undergoing a FEEL examination during ongoing cardiac arrest (100) and in a shock state (104). Images of diagnostic quality were obtained in 96%. In 35% of those with an ECG diagnosis of asystole, and 58% of those with PEA, coordinated cardiac motion was detected, and associated with increased survival. Echocardiographic findings altered management in 78% of cases.
Conclusions: Application of ALS-compliant echocardiography in pre-hospital care is feasible, and alters diagnosis and management in a significant number of patients. Further research into its effect on patient outcomes is warranted.
Focused echocardiographic evaluation in life support and peri-resuscitation of
emergency patients: A prospective trial

Resuscitation. 2010 Nov;81(11):1527-33

The Sichuan Straddle

I used to see it done on ‘ER’ but never knew people really straddled patients on stretchers doing CPR. Apparently they do in Sichuan, China and have now produced a manikin study to demonstrate its effectiveness. It might work there, but I imagine there are frequent situations in Australia (where I work) in which the combined weight of patient and paramedic would present an unfair load to the stretcher.

OBJECTIVE: To evaluate the efficacy of straddling external chest compression performed on moving stretchers.
METHODS: The study was a prospective, randomized, cross-over study on a manikin performed at a university hospital. Twenty subjects were selected from the 40 graduates using random numbers to participate in the study. Participants were randomized to either performing standard or straddling external chest compression followed by the other technique 7 days later. The compression variables and time to first compression were recorded.
RESULTS: Twenty subjects (12 males and 8 females) took part in the study. There were no differences between the standard and straddling external chest compression for the compression rate, effective compression percentage and compression depth. There was no difference between the standard external chest compression and straddling external chest compression for incorrect hand position and incomplete release compression. Time to first compression during straddling external chest compression (10.31 ± 1.65 s) was greater than that during standard external chest compression (2.74 ± 0.40 s) (P < 0.001).
CONCLUSIONS: The quality of straddling external chest compression performed on a moving stretcher was as effective as standard external chest compression performed on the floor. By performing straddling external chest compression, time for transporting victims to the emergency department to get advanced life support may be shortened.
The efficacy of straddling external chest compression on a moving stretcher
Resuscitation. 2010 Nov;81(11):1562

CPR on your own? Stay at the head end

In this manikin study, single-rescuer bag-mask ventilation (BMV) with chest compressions was tried in three different positions. Staying at the head end to deliver effective BMV, with ‘over-the-head’ chest compressions from that position, was best.

Background The 2005 guidelines for cardiopulmonary resuscitation (CPR) do not include a statement on performance of basic life support by a single healthcare professional using a bagevalveemask device. Three positions are possible: chest compressions and ventilations from over the head of the casualty (over-the-head CPR), from the side of the casualty (lateral CPR), and chest compressions from the side and ventilations from over the head of the casualty (alternating CPR). The aim of this study was to compare CPR quality of these three positions.
Methods 102 healthcare professionals were randomised to a crossover design and performed a 2-min CPR test on a manikin for each position.
Results The hands-off time over a 2-min interval was not significantly different between over-the-head (median 31 s) and lateral (31 s) CPR, but these compared favourably with alternating CPR (36 s). Over-the-head CPR resulted in significantly more chest compressions (155) compared with lateral (152) and alternating CPR (149); the number of correct chest compressions did not differ significantly (119 vs 122 vs 109). Alternating CPR resulted in significantly less inflations (eight) compared with over-the-head (ten) and lateral CPR (ten). Lateral CPR led to significantly less correct inflations (three) compared with over-the-head (five) and alternating CPR (four).
Conclusions In the case of a single healthcare professional using a bagevalveemask device, the quality of over-the-head CPR is at least equivalent to lateral, and superior to alternating CPR. Because of the potential difficulties in bagevalveemask ventilation in the lateral position, the authors recommend over-the-head CPR.
Comparison of the over-the-head, lateral and alternating positions during cardiopulmonary resuscitation performed by a single rescuer with a bag valve mask device
Emerg Med J. 2010 Oct 14. [Epub ahead of print]

How to give cold saline in the field

Pre-hospital therapeutic hypothermia might be a good thing, but there may be difficulties in achieving it if the 4 degrees C saline warms up during the infusion. What’s the optimal way of administering it? Czech investigators attempt to answer the question:
Background The cooling efficacy of intravenous administration of cold crystalloids can be enhanced by optimisation of the procedure. This study assessed the temperature stability of different application regimens of cold normal saline (NS) in simulated prehospital conditions.

Methods Twelve different application regimens of 4°C cold NS (volumes of 250, 500 and 1000 ml applied at infusion rates of 1000, 2000, 4000 and 6000 ml/h) were investigated for infusion temperature changes during administration to an artificial detention reservoir in simulated prehospital conditions.
Results An increase in infusion temperature was observed in all regimens, with an average of 8.163.38C (p<0.001). This was most intense during application of the residual 20% of the initial volume. The lowest rewarming was exhibited in regimens with 250 and 500 ml bags applied at an infusion rate of 6000 ml/h and 250 ml applied at 4000 ml/h. More intense, but clinically acceptable, rewarming presented in regimens with 500 and 1000 ml bags administered at 4000 ml/h, 1000 ml at 6000 ml/h and 250 ml applied at 2000 ml/h. Other regimens were burdened by excessive rewarming.
Conclusion Rewarming of cold NS during application in prehospital conditions is a typical occurrence. Considering that the use of 250 ml bags means the infusion must be exchanged too frequently during cooling, the use of 500 or 1000 ml NS bags applied at an infusion rate of $4000 ml/h and termination of the infusion when 80% of the infusion volume has been administered is regarded as optimal.
Prehospital cooling by cold infusion: searching for the optimal infusion regimen
Emerg Med J. 2010 Aug 23. [Epub ahead of print]

End tidal CO2 in cardiac arrest

Measuring end-tidal CO2 in cardiac arrest patients is helpful for

  1. confirming tracheal tube placement
  2. assessing the effectiveness of chest compressions
  3. predicting likelihood of return of spontaneous circulation (ROSC), in that a persistently low ETCO2 tends to predict death, whereas a high or rising ETCO2 is associated with a higher chance of ROSC.

It may be however that its predictive ability depends on the type of cardiac arrest, and how far into the resuscitation you’ve got when you measure the ETCO2. Consider this new study from Slovenian pre-hospital emergency physicians:
Methods: The study included two cohorts of patients: cardiac arrest due to asphyxia with initial rhythm asystole or pulseless electrical activity (PEA), and cardiac arrest due to arrhythmia with initial rhythm VF or pulseless VT. The causes of asphyxia were: asthma, severe acute respiratory failure, tumor of the airway, suicide by hanging, acute intoxication, pneumonia and a foreign body in the airway.PetCO2 was measured for both groups immediately after intubation and repeatedly every minute, both for patients with or without return of spontaneous circulation (ROSC). We compared the dynamic pattern of PetCO2 between groups. Resuscitation procedures were performed by an emergency medical team (emergency medical physician and two emergency medical technicians or registered nurses) in accordance with 2005 ERC Guideline
Results: Between June 2006 and June 2009 resuscitation was attempted in 325 patients and in this study we included 51 patients with asphyxial cardiac arrest and 63 patients with VF/VT cardiac arrest. The initial values of PetCO2 were significantly higher in the group with asphyxial cardiac arrest (6.74 ± 4.22 kilopascals (kPa) versus 4.51 ± 2.47 kPa; P = 0.004). In the group with asphyxial cardiac arrest, the initial values of PetCO2 did not show a significant difference when we compared patients with and without ROSC (6.96 ± 3.63 kPa versus 5.77 ± 4.64 kPa; P = 0.313). We confirmed significantly higher initial PetCO2 values for those with ROSC in the group with primary cardiac arrest (4.62 ± 2.46 kPa versus 3.29 ± 1.76 kPa; P = 0.041).

A significant difference in PetCO2 values for those with and without ROSC was achieved after five minutes of CPR in both groups (asphyxial arrest: 6.09 ± 2.63 kPa versus 4.47 ± 3.35 kPa; P = 0.006; primary arrest: 5.63 ± 2.01 kPa versus 4.26 ± 1.86; P = 0.015)
In mmHg, the PetCO2 values for those with and without ROSC after five minutes of CPR was: asphyxial arrest: 42.3 ± 20 mmHg versus 34 ± 25.5 mmHg; P = 0.006; primary arrest: 42.8 ± 15.3 mmHg versus 32.3 ± 14.1 mmHg; P = 0.015
Graphically, this difference in ROSC vs non-ROSC PetCO2 for both groups appeared to be even greater at ten minutes, with higher statistically significance (p<0.001), although the values of PetCO2 are not given in the paper.
In all patients with ROSC the initial PetCO2 was again higher than 1.33 kPa (10.1 mmHg).
Conclusions: The dynamic pattern of PetCO2 values during out-of-hospital CPR showed higher values of PetCO2 in the first two minutes of CPR in asphyxia, and a prognostic value of initial PetCO2 only in primary VF/VT cardiac arrest. A prognostic value of PetCO2 for ROSC was achieved after the fifth minute of CPR in both groups and remained present until final values. This difference seems to be a useful criterion in pre-hospital diagnostic procedures and attendance of cardiac arrest.
The authors summarise with the following key messages:

  • Initial values of PetCO2 are higher in asphyxial cardiac arrest than in primary cardiac arrest.
  • Initial values of PetCO2 in asphyxial cardiac arrest do not have a prognostic value for resuscitation outcome.
  • The prognostic value of PetCO2 for ROSC was achieved after the fifth minute of CPR in both groups and remained present until the final values.
  • The values of PetCO2 seem to be useful in differentiating the causes of cardiac arrest in a pre-hospital setting.

I think that last one’s a bit of a stretch. For me, this paper confirms that the longer you are into a cardiac arrest resuscitation, the worse news a low PetCO2 is. The lack of predictive value of initial PetCO2, particularly in the asphyxia group, is interesting but not surprising.
The dynamic pattern of end-tidal carbon dioxide during cardiopulmonary resuscitation: difference between asphyxial cardiac arrest and ventricular fibrillation/pulseless ventricular tachycardia cardiac arrest
Critical Care 2011, 15:R13

Pre-hospital therapeutic hypothermia

A Czech study demonstrated effective pre-hospital therapeutic cooling of post-cardiac arrest patients using fairly modest amounts of intravenous saline at 4°C: the administration of 12.6 ± 6.4 mL/kg (1,032 ± 546 mL) of 4°C normal saline led to a tympanic temperature decrease of 1.4 ± 0.8°C (from 36.2 ± 1.5 to 34.7 ± 1.4°C; P < 0.001) in 42.8 ± 19.6 minutes. No ice packs were applied.

Before other emergency medical services adopt this, it should be noted that all these patients were managed in the field by emergency physicians who administered sedatives and neuromuscular blockers. It’s a European thing.
Pre-hospital cooling of patients following cardiac arrest is effective using even low volumes of cold saline
Critical Care 2010, 14:R231 Full text