Chest Compression Fraction in Simulated Cardiac Arrest Management by Primary Care Paramedics: King Laryngeal Tube Airway versus Basic Airway Management

Prehospital Emergency Care: Posted online on January 10, 2013.

The objective of this randomised simulation study was to determine whether use of the King laryngeal tube (KLT) airway resulted in differences in chest compression fraction (CCF) during simulated cardiac arrest managed by primary care paramedics (PCPs), as compared with basic airway management (bag–mask ventilation [BMV]).

© Gary Wilson/ Pre-hospital Research Forum

The KLT was introduced to all providers in the EMS system at the time of study initiation. All participants received the same training, and were not aware that the primary outcome of the study was CCF. Standard airway management by PCPs prior to this was BMV. Pairs of PCPs were randomized to use KLT or BMV during a scripted 6-minute cardiac arrest scenario. The scenarios were videotaped, and data were abstracted by a single investigator. The CCF was calculated (fraction of time chest compressions were done/total scenario time). The CCF, number of seconds to first ventilation, and number of seconds to first compression were compared using the Mann-Whitney U test.

Sixty-seven pairs of PCPs participated: 30 in the KLT arm and 37 in the BMV arm. Demographics were similar in each group: KLT 68.3% males, BMV 55.4% males; KLT mean age 33.52 years), BMV mean age 32.07 years; and KLT mean years of experience 9.03, BMV mean years of experience 6.59. The CCF was higher in the KLT group: median 0.82 compared with the BMV group: median 0.70. Time to first ventilation was longer in the KLT group: median 83.00 sec than in the BMV group: median 48.00 sec. Times to first compression were similar: KLT median 13.00 sec, BMV median 14.00 sec .

It was found in this randomised simulation study, KLT use by PCPs during simulated standard cardiac arrest scenarios was found to significantly increase CCF compared with basic airway management with BMV. These results are likely to be seen with majority of types of supraglottic airways when compared with basic airway management methods as once the device is correctly located, the requirement to maintain an effective seal, one of the interruptions to effective CPR, is eliminated and continuous compressions can be performed. Considering the results state it took 35 seconds longer to achieve the first ventilation with the KLT, it should be noted that about a third of KLT pairs placed the device before providing the first ventilation while others placed the KLT at just over two minutes into the scenario. The amount of time without CPR per minute of the scenario was the same in both groups in the first 3 minutes, but significantly less in minutes 3 to 6 when the KLT was used.

The authors also note that while the study provides some evidence that the use of KLT may improve CCF, it is unknown how this would translate into the real-world setting, or whether this intervention would improve survival.

http://informahealthcare.com/doi/abs/10.3109/10903127.2012.744784

A Pilot Study Examining the Viability of a Prehospital Assessment with UltraSound for Emergencies (PAUSE) Protocol

The Journal of Emergency Medicine: Volume 44, Issue 1 , Pages 142-149, January 2013

Prehospital ultrasound has been shown to aid in the diagnosis of multiple conditions that do not generally change prehospital management. On the other hand, the diagnoses of cardiac tamponade, tension pneumothorax, or cardiac standstill may directly impact patient resuscitation in the field. The authors wanted to determine if prehospital care providers can learn to acquire and recognise ultrasound images for several life-threatening conditions using the Prehospital Assessment with UltraSound for Emergencies (PAUSE) protocol.

This was a prospective, educational intervention pilot study at an urban fire department with integrated emergency medical services (EMS). 20 emergency medical technicians – paramedic with no prior ultrasonography training were enrolled into the study. Subjects underwent a 2-h training session on basic ultrasonography of the lungs and heart to evaluate for pneumothorax, pericardial effusion, and cardiac activity. Subjects were tested on image interpretation as well as image acquisition skills. Two bedside ultrasound-trained emergency physicians scored images for adequacy. Image interpretation testing was performed using pre-obtained ultrasound clips containing normal and abnormal images.

All subjects appropriately identified the pleural line, and 19 of 20 paramedics achieved a Cardiac Ultrasound Structural Assessment Scale score of ≥4. For the image interpretation phase, the mean PAUSE protocol video test score was 9.1 out of a possible 10 (95% confidence interval 8.6–9.6).

The authors found that paramedics were able to perform the PAUSE protocol and recognise the presence of pneumothorax, pericardial effusion, and cardiac standstill. The PAUSE protocol may potentially be useful in rapidly detecting specific life-threatening pathology in the prehospital environment, and warrants further study in existing EMS systems.

http://www.jem-journal.com/article/S0736-4679(12)00253-3/abstract?elsca1=etoc&elsca2=email&elsca3=0736-4679_201301_44_1&elsca4=emergency_medicine

The NEXUS criteria: do they stand the test of time?

European Journal of Emergency Medicine: February 2013 – Volume 20 – Issue 1 – p 58–60

The National Emergency X-ray Utilisation Study (NEXUS) criteria and the Canadian cervical spine rules are validated clinical decision-making tools used to facilitate selective cervical spine (C-spine) radiography. The NEXUS criteria are frequently used, as the Canadian cervical spine rules have been noted to be difficult to learn, remember and implement. While the rules are often used to decide whether radiography is required, the questions asked are similar to the should we immobilise questions asked by pre-hospital care providers.

© Gary Wilson/ Pre-hospital Research Forum

In this article the authors present a series of significant C-spine injury in three elderly patients who would not have warranted C-spine imaging using the NEXUS criteria. Each patient was mobile and fully orientated after the injury. There was no midline tenderness, neurological deficit, distracting injury or alcohol/drug involvement. Plain film imaging was initially performed as each patient had a reduced range of movement. Significant odontoid peg injury was confirmed on subsequent computed tomography/MRI imaging for all patients.

Despite previous validation studies of the NEXUS criteria in the elderly population, the authors urge caution in using the NEXUS criteria alone in determining radiography of the C-spine in the elderly. Similarly, the pathophysiological changes associated of ageing, mechanism of injury, history and patient presentation should be incorporated into the elderly patient assessment before the immobilisation decision is made rather than simply following C-spine immobilisation rules.

http://journals.lww.com/euro-emergencymed/Abstract/2013/02000/The_NEXUS_criteria___do_they_stand_the_test_of.12.aspx.

For more information on the NEXUS and Canadian cervical spine rules, the following article, while ten years old, provides a good comparison between the two methods:

The Canadian C-Spine Rule versus the NEXUS Low-Risk Criteria in Patients with Trauma

N Engl J Med 2003; 349:2510-2518December 25, 2003

Full text article at: http://www.nejm.org/doi/full/10.1056/NEJMoa031375#t=articleTop

Endotracheal Tube Cuff Pressure before, during, and after Fixed-Wing Air Medical Retrieval

Prehospital Emergency Care: Posted online on December 19, 2012.

Increased endotracheal tube (ETT) cuff pressure is associated with compromised tracheal mucosal perfusion and injuries. but no published data is available for Australia on pressures in the fixed-wing air medical retrieval setting.

© Gary Wilson/ Pre-hospital Research Forum

After the introduction of a cuff pressure manometer at the Royal Flying Doctor Service (RFDS) Base in Dubbo, New South Wales (NSW), Australia, the authors assessed the prevalence of increased cuff pressures before, during, and after air medical retrieval.

This was a retrospective audit in 35 ventilated patients during fixed-wing retrievals by the RFDS in NSW, Australia. Explicit chart review of ventilated patients was performed for cuff pressures and changes during medical retrievals with pressurized aircrafts. Pearson correlation was calculated to determine the relation of ascent and ETT cuff pressure change from ground to flight level.

It was found that the mean (± standard deviation) of the first ETT cuff pressure measurement on the ground was 44 ± 20 cm H2O. Prior to retrieval in 11 patients, the ETT cuff pressure was >30 cm H2O and in 11 patients >50 cm H2O. After ascent to cruising altitude, the cuff pressure was >30 cm H2O in 22 patients and >50 cm H2O in eight patients. The cuff pressure was reduced 1) in 72% of cases prior to take off and 2) in 85% of cases during flight, and 3) after landing, the cuff pressure increased in 85% of cases.

The authors believe that the high prevalence of excessive cuff pressures during air medical retrieval can be avoided by the use of cuff pressure manometers.

http://informahealthcare.com/doi/abs/10.3109/10903127.2012.744787

Blood Administration in Helicopter Emergency Medical Services Patients Associated With Hypothermia

Air Medical Journal: Volume 32, Issue 1 , Pages 47-51, January 2013

The infusion of packed red blood cells (PRBCs) in the severely injured patient is not a new practice. It is a potentially lifesaving procedure although it is not without inherent risk. This practice in the helicopter emergency medical services (HEMS) has not been examined in the literature. The authors wanted to attempt to determine the factors associated with hypothermia (ie, < 35°C), including the transfusion of O negative blood.

© Gary Wilson/ Pre-hospital Research Forum

This was a retrospective review using the trauma registry on all patients who arrived at the authors’ rural level 1 trauma center by HEMS from January 1, 2005, through June 30, 2009 [Dartmouth-Hitchcock Medical Center, Lebanon, NH]. Patient temperature on arrival was compared for patients with and without hypothermia transported by the HEMS service.

During the study period, there were 707 HEMS transports. Sixty (8.5%) were hypothermic, and 30 (4.2%) received PRBCs. There was a high likelihood of PRBC patients with hypothermia (odds ratio = 6.27; 95%).

The authors found that HEMS trauma patients who have received blood are more likely to arrive hypothermic (ie, < 35°C). The clinical impact of giving PRBCs in the HEMS prehospital setting was not determined.

http://www.airmedicaljournal.com/article/S1067-991X(12)00052-1/abstract?elsca1=etoc&elsca2=email&elsca3=1067-991X_201301_32_1&elsca4=emergency_medicine

Review article: Paramedic education opportunities and challenges in Australia

Emergency Medicine Australasia: Article first published online: 25 Dec 2012

Paramedic education has been undergoing major development in Australia in the past 20 years, with many different educational programmes being developed across all Australian jurisdictions.

This article aims to review the current paramedic education programmes in Australia to identify the similarities and differences between the programmes, and the strengths and challenges in these programmes. A literature search was performed using six scientific databases to identify any systematic reviews, literature reviews or relevant articles on the topic. Additional searches included journal articles and text references from 1995 to 2011. The search was conducted during December 2010 and November 2011.

© Gary Wilson/ Pre-hospital Research Forum

Included in this review are a total of 28 articles, which are focused around five major issues in paramedic education:

(i) principle on paramedic programmes and the involvement of industry partners;

(ii) clinical placements;

(iii) contemporary methods of education;

(iv) needs for specific programmes within paramedic education; and

(v) articles related to the accreditation process for paramedic programmes. Paramedic programmes across Australian universities vary with many different practices, especially relating to clinical placements in the field. The further advances of the paramedic education programmes should aim to respond to population change and industry development, which would enhance the paramedic profession across Australia.

http://onlinelibrary.wiley.com/doi/10.1111/1742-6723.12034/abstract

Clinical Events and Treatment in Prehospital Patients with ST-segment Elevation Myocardial Infarction

Prehospital Emergency Care: Posted online on January 2, 2013.

Little is known about clinically important events and advanced care treatment that patients with ST-segment elevation myocardial infarction (STEMI) encounter in the prehospital setting.

© Gary Wilson/ Pre-hospital Research Forum

The authors sought to determine the proportion of community patients with STEMI who experienced a clinically important event or received advanced care treatment prior to arrival at a designated percutaneous coronary intervention (PCI) laboratory or emergency department (ED).

The authors reviewed 487 consecutive community patients with STEMI between May 2008 and June 2009. All patients were geographically within a single large “third-service” urban emergency medical services (EMS) system and were transported by paramedics with an advanced care scope of practice. Predefined clinically important events and advanced care treatment that occurred in patients being transported directly to a PCI laboratory or ED (group 1) or interfacility transfer to a PCI laboratory (group 2) were recorded.

One or more clinically important events occurred in 92 of 342 (26.9%) group 1 patients and nine of 145 (6.2%) group 2 patients. The most common were sinus bradycardia, hypotension, and cardiac arrest. Additionally, 33 of 342 (9.6%) group 1 and nine of 145 (6.2%) group 2 patients received one or more advanced care treatments. The most common were administration of morphine and administration of atropine. Eight group 1 patients and three group 2 patients received cardiopulmonary resuscitation (CPR) or defibrillation.

Clinically important events and advanced care treatment are common in community STEMI patients undergoing prehospital transport or interfacility transfer to a PCI center. Several patients required CPR or defibrillation. The authors recommend further research to define the clinical experience of STEMI patients during the out-of-hospital phase and the scope of practice required of EMS providers to safely manage these patients.

http://informahealthcare.com/doi/abs/10.3109/10903127.2012.744783

Successful Management of Excited Delirium Syndrome with Prehospital Ketamine: Two Case Examples

Prehospital Emergency Care: Posted online on December 11, 2012.

Ketamine appears to be receiving increased interest and use by pre-hospital providers. This case study describes successful use of ketamine to manage two difficult patients.

Excited delirium syndrome (ExDS) is a medical emergency usually presenting first in the prehospital environment. Untreated ExDS is associated with a high mortality rate and is gaining recognition within organized medicine as an emerging public safety problem. It is highly associated with male gender, middle age, chronic illicit stimulant abuse, and mental illness.

Management of ExDS often begins in the field when first responders, law enforcement personnel, and emergency medical services (EMS) personnel respond to requests from witnesses who observe subjects exhibiting bizarre, agitated behavior. Although appropriate prehospital management of subjects with ExDS is still under study, there is increasing awareness of the danger of untreated ExDS, and the danger associated with the need for subject restraint, whether physical or chemical.

The authors describe two ExDS patients who were successfully chemically restrained with ketamine in the prehospital environment, and who had good outcomes without complication. These are claimed to be among the first case reports in the literature of ExDS survival without complication using this novel prehospital sedation management protocol. This strategy bears further study and surveillance by the prehospital care community for evaluation of side effects and unintended complications.

http://informahealthcare.com/doi/abs/10.3109/10903127.2012.729129

Impact of Delayed and Infrequent Administration of Vasopressors on Return of Spontaneous Circulation during Out-of-Hospital Cardiac Arrest

Prehospital Emergency Care: January-March 2013, Vol. 17, No. 1 , Pages 15-22

Epinephrine and vasopressin are the only vasopressors associated with return of spontaneous circulation (ROSC). While current guidelines recommend rapid and frequent vasopressor administration during cardiac arrest, delays in their administration in the out-of- hospital setting remain a concern.

This study evaluated delays in vasopressor administration and their effect on field ROSC.

This retrospective review included all adult patients who experienced cardiac arrest of medical origin and received field resuscitative efforts among 10 emergency medical services (EMS) systems. Data were abstracted from the EMS medical record and included response time intervals, calculated first-dose and interdosing intervals of vasopressors, and ROSC. Data were analyzed using Mann-Whitney tests, chi-square tests, and t-tests, survival analysis, and logistic regression, with p ≤ 0.05 indicating significance.

© Gary Wilson/ Pre-hospital Research Forum

A total of 660 cardiac arrest patients were enrolled in the study. It was found that the mean EMS response time was 8.8 minutes; 52.7% of patients had witnessed cardiac arrests, 46.2% received bystander cardiopulmonary resuscitation (CPR), 23.0% had shockable initial rhythms, and 19.5% experienced field ROSC. In total, 1,913 doses of epinephrine and 111 doses of vasopressin were administered, with mean and 90th-percentile scene arrival–to–first drug intervals of 9.5 and 17 minutes, respectively. The mean and 90th-percentile interdosing intervals were 6.1 and 10 minutes, respectively. Patients experiencing ROSC had shorter scene arrival–to–first drug intervals than those without ROSC (8.1 vs. 9.8 min), but there was no difference in the mean interdosing interval (6.8 vs. 6.0 min). In the logistic regression analysis of ROSC, the adjusted odds ratio for call receipt–to–first drug interval ≤10 minutes was 1.91). Patients receiving advanced airway control prior to vasopressor administration were less likely to have a call receipt–to–first drug interval within 10 minutes (4.0% vs. 17.3%) and were less likely to attain ROSC (15.7% vs. 25.4%).

The authors found that the interval between scene arrival and first administration of vasopressors is significantly shorter among patients who experience ROSC compared with those who do not. Airway control procedures delay vasopressor administration and reduce the likelihood of ROSC. Although the interdosing intervals of most patients were not consistent with current recommendations, there was no difference in the mean interdosing times between those who achieved ROSC and those who did not.

http://informahealthcare.com/doi/abs/10.3109/10903127.2012.702193