Joseph Clinton

Emergency noninvasive external cardiac pacing

Thirty-seven critical emergency department patients underwent attempts at external cardiac pacing over an 11-month period. Indications for pacing were asystole in 16, complete heart block (CHB) in 4, sinus bradycardia in 2, nodal bradycardia in 1, atrial fibrillation with bradycardia in 2, electromechanical dissociation in 1, idioventricular rhythm (IVR) in 10, and torsades de pointes in 1. Eight patients were successfully paced with improvement in their condition. Two were in asystole, two in CHB, three in sinus rhythm or atrial fibrillation with bradycardia, and one in idioventricular rhythm. Mean systolic blood pressure rise with pacing was 95 +/- 50 mm Hg. Six of these patients were ultimately discharged from the hospital. One asystolic patient survived to discharge. Other survivors presented with either CHB or bradycardia. Of the 29 patients who did not respond to pacing, 5 survived to hospital discharge. Surviving nonresponder presenting rhythms were CHB in one patient, sinus or nodal bradycardia in two, IVR in one, and torsades de pointes in one. External cardiac pacemaking appears to be effective in hemodynamically significant bradycardia. It does not appear to be effective in most instances of asystole or IVR resulting from prolonged cardiac arrest. When applied to patients with a responsive myocardium, it may result in significant hemodynamic improvement and may be lifesaving.

Prehospital Ultrasound Diagnosis of Traumatic Pericardial Effusion

A 41-year-old male was stabbed in the left chest. When paramedics arrived at the scene, the patient was unconscious. The airway was managed with a nasal trumpet, and the patient was quickly moved to the ambulance. The systolic blood pressure was 85 mm Hg. In the ambulance, one paramedic performed a bedside, prehospital ultrasound (PUS) using a SonoSite MicroMaxx (Sonosite Inc., Bothell, WA) with a P17 probe using a subcostal cardiac view. A large pericardial effusion with hyperechoic and anechoic fluid in the pericardial sac was identified (Figure 1, Video Clip S1, available as supporting information in the online version of this paper). Based on this ultrasound finding, the decision was made to immediately transport the patient to the closest Level 1 trauma center, with intravenous fluids administered enroute. The total emergency medical systems (EMS) scene time was 9 minutes and transport time was 6 minutes. The PUS took less than 1 minute to obtain and did not impact transport times. The emergency department was alerted that a patient with a hypotensive stab wound to the heart with a positive sonographic pericardial effusion was enroute. The patient was quickly assessed in the emergency department. The emergency physicians and trauma surgeons reviewed the PUS video. The patient was taken directly to the operating room based on the PUS video, and a median sternotomy was performed with evacuation of a large mixed-density clot and repair of a right ventricular stab wound using a single 3.0 Prolene suture with pledget. The patient had an uneventful postoperative course and was discharged from the hospital 4 days later with complete neurologic recovery. Prehospital ultrasound has been used in our EMS system on a limited basis for the past 12 months. This case demonstrates that EMS personnel can be adequately trained to utilize this technology to shorten time to determining certain diagnoses and facilitate proper destination decisions, which can improve overall patient care. This case is part of a larger PUS study that was approved by our institutional review board.

AN IMPEDANCE THRESHOLD DEVICE INCREASES BLOOD PRESSURE IN HYPOTENSIVE PATIENTS

BACKGROUNDnThe impedance threshold device (ITD-7) augments the vacuum created in the thorax with each inspiration, thereby enhancing blood flow from the extrathoracic venous systems into the heart.nnnOBJECTIVESnTo the best of our knowledge, the ITD-7 has not previously been investigated in hypotensive patients in the emergency department (ED) or the prehospital setting. The objective of this study was to determine whether the ITD-7 would increase systolic arterial pressures in hypotensive spontaneously breathing patients.nnnMETHODSnThe ED study was a prospective, randomized, double-blind, sham control design. Patients with a systolic blood pressure ≤ 95 mm Hg were randomized to breathe for 10 min through an active or sham ITD. The primary endpoint was the change in systolic blood pressure measured non-invasively. The prehospital study was a prospective, non-blinded evaluation of the ITD-7 in hypotensive patients.nnnRESULTSnIn the ED study, the mean ± standard deviation rise in systolic blood pressure was 12.9 ± 8.5 mm Hg for patients (n = 16) treated with an active ITD-7 vs. 5.9 ± 5.9 mm Hg for patients (n = 18) treated with a sham ITD-7 (p < 0.01). In the prehospital study, the mean systolic blood pressure before the ITD-7 was 79.4 ± 10.2 mm Hg and 107.3 ± 17.6 mm Hg during ITD-7 use (n = 47 patients) (p < 0.01).nnnCONCLUSIONnDuring this clinical evaluation of the ITD-7 for the treatment of hypotensive patients in the ED and in the prehospital setting, use of the device significantly increased systolic blood pressure and was safe and generally well tolerated.

Hospital Response to a Major Freeway Bridge Collapse

BACKGROUNDnWe describe the hospital system response to the Interstate 35W bridge collapse in Minneapolis into the Mississippi River on August 1, 2007, which resulted in 13 deaths and 127 injuries. Comparative analysis of response activities at the 3 hospitals that received critical or serious casualties is provided.nnnMETHODSnFirst-hand experiences of hospital physicians, issues identified in after-action reports, injury severity scores, and other relevant patient data were collected from the 3 hospitals that received seriously injured patients, including the closest hospitals to the collapse on each side of the river.nnnRESULTS/DISCUSSIONnInjuries were consistent with major acceleration/deceleration force injuries. The most critical patients arrived first at each hospital, suggesting appropriate prehospital triage. Capacity of the health care system was not overwhelmed and the involved hospitals generally reported an overresponse by staff. Communication and patient tracking problems occurred at all of the hospitals. Situational awareness was limited due to the scope of structural collapse and incomplete information from the scene.nnnCONCLUSIONSnHospitals were generally satisfied with their surge capacity and incident management plan activation. Issues such as communications, patient tracking, and staff overreporting that have been identified in past incidents also were problematic in this event. Hospitals will need to address deficiencies and build on successful actions to cope with future, potentially larger incidents.

Emergency medical services response to a major freeway bridge collapse

BACKGROUNDnThe Interstate 35W Bridge in Minneapolis collapsed into the Mississippi River on August 1, 2007, killing 13 people and injuring 127.nnnMETHODSnThis article describes the emergency medical services response to this incident.nnnRESULTS/DISCUSSIONnComplexities of the event included difficult patient access, multiple sectors of operation, and multiple mutual-aid agencies. Patient evacuation and transportation was rapid, with the collapse zone cleared of victims 95 minutes after the initial 9-1-1 call. A common regional emergency medical service incident management plan that was exercised was critical to the success of the response.nnnCONCLUSIONSnCommunication and patient tracking difficulties could be improved in future responses.

Reliability and Validity of a Test Designed to Assess Combat Medics' Readiness to Perform Life-Saving Procedures

OBJECTIVESnReducing preventable deaths because of uncontrolled hemorrhage, tension pneumothorax, and airway loss is a priority. As part of a research initiative comparing different training models, this study evaluated the reliability and validity of a test that assesses combat medic performance during a polytrauma scenario using live animal models.nnnMETHODSnNine procedural checklists and seven global rating scales were piloted with four cohorts of soldiers (n = 94) at two U.S. training sites. Cohorts represented novice to proficient trainees. Procedure scores and a mean global score were calculated per subject. The intraclass correlation was calculated per procedure, with 0.70 as the threshold for acceptability. An overall difference among cohorts was hypothesized: Cohort 4 (proficient) > Cohort 3 (competent) > Cohort 2 (beginners) > Cohort 1 (novice) trainees. Data were analyzed using Kruskal-Wallis and analysis of variance.nnnRESULTSnAt Site A, intraclass correlation coefficients ranged from 74% to 93% for 6 of 9 procedures. Cohorts differed significantly on hemorrhage control, needle decompression, cricothyrotomy, amputation management, chest tube insertion, and mean global scores. Cohort 4 outperformed the others, and Cohorts 2 and 3 outperformed Cohort 1.nnnCONCLUSIONnThe test differentiates novices from beginners, competent, and proficient trainees on difficult procedures and overall performance.

Training and Assessing Critical Airway, Breathing and Hemorrhage Control Procedures for Trauma Care: Live Tissue versus Synthetic Models

INTRODUCTIONnOptimal teaching and assessment methods and models for emergency airway, breathing, and hemorrhage interventions are not currently known. The University of Minnesota Combat Casualty Training consortium (UMN CCTC) was formed to explore the strengths and weaknesses of synthetic training models (STMs) versus live tissue (LT) models. In this study, we compare the effectiveness of best in class STMs versus an anesthetized caprine (goat) model for training and assessing seven procedures: junctional hemorrhage control, tourniquet (TQ) placement, chest seal, needle thoracostomy (NCD), nasopharyngeal airway (NPA), tube thoracostomy, and cricothyrotomy (Cric).nnnMETHODSnArmy combat medics were randomized to one of four groups: 1) LT trained-LT tested (LT-LT), 2) LT trained-STM tested (LT-STM), 3) STM trained-LT tested (STM-LT), and 4) STM trained-STM tested (STM-STM). Participants trained in small groups for 3 to 4 hours and were evaluated individually. LT-LT was the control to which other groups were compared, as this is the current military predeployment standard. The mean procedural scores (PSs) were compared using a pairwise t-test with a Dunnetts correction. Logistic regression was used to compare critical fails (CFs) and skipped tasks.nnnRESULTSnThere were 559 subjects included. Junctional hemorrhage control revealed no difference in CFs, but LT-tested subjects (LT-LT and STM-LT) skipped this task more than STM-tested subjects (LT-STM and STM-STM; pxa0<xa00.05), and STM-STM had higher PSs than LT-LT (pxa0<xa00.001). For TQ, both STM-tested groups (LT-STM and STM-STM) had more CFs than LT-LT (pxa0<xa00.001) and LT-STM had lower PSs than LT-LT (pxa0<xa00.05). No differences were seen for chest seal. For NCD, LT-STM had more CFs than LT-LT (pxa0=xa00.001) and lower PSs (pxa0=xa00.001). There was no difference in CFs for NPA, but all groups had worse PSs versus LT-LT (pxa0<xa00.05). Forxa0Cric, we were underpowered; STM-LT trended toward more CFs (pxa0=xa00.08), and STM-STM had higher PSs than LT-LT (pxa0<xa00.01). Tube thoracostomy revealed that STM-LT had higher CFs than LT-LT (pxa0<xa00.05), but LT-STM had lower PSs (pxa0<xa00.05). An interaction effect (making the subjects who trained and tested on different models more likely to CF) was only found for TQ, chest seal, and Cric; however, of these three procedures, only TQ demonstrated any significant difference in CF rates.nnnCONCLUSIONnTraining on STM or LT did not demonstrate a difference in subsequent performance for five of seven procedures (junctional hemorrhage, TQ, chest seal, NPA, and NCD). Until STMs are developed with improved anthropomorphic and tissue fidelity, there may still be a role for LT for training tube thoracostomy and potentially Cric. For assessment, our STM appears more challenging for TQ and potentially for NCD than LT. For junctional hemorrhage, the increased skips with LT may be explained by the differences in anatomic fidelity. While these results begin to uncover the effects of training and assessing these procedures on various models, further study is needed to ascertain how well performance on an STM or LT model translates to the human model.

Prehospital Chemical Restraint of a Noncommunicative Autistic Minor by Law Enforcement

Abstract When responders are dealing with an agitated patient in the field, safety for all involved may sometimes only be accomplished with physical or chemical restraints. While experiences using chemical restraint in the prehospital setting are found in the medical literature, the use of this by law enforcement as a first-response restraint has not previously been described. We report a case of successful law enforcement–administered sedation of a noncommunicative, autistic, and violent minor using intramuscular droperidol and diphenhydramine. Although this case has some unique characteristics that allowed chemical restraint to be given by the law enforcement agency, it calls attention to some specific prehospital issues that need to be addressed when dealing with autistic patients with extreme agitation.

Validation of an Assessment Tool for Field Endotracheal Intubation.

OBJECTIVESnEndotracheal intubation (ETI) is an important skill for all emergency providers; our ability to train and assess our learners is integral to providing optimal patient care. The primary aim of this study was to assess the inter-rater reliability (IRR) and discriminant validity of a novel field ETI assessment tool using a checklist-derived performance score (PS) and critical failure (CF) rate.nnnMETHODSnForty-three participants (18 paramedic students, 11 paramedics, and 14 emergency physicians [EPs]) performed ETI during a simulated trauma scenario on a pseudo-ventilated cadaver. Each participant was assessed by two experienced raters. IRR was calculated using the intraclass correlation coefficient. Regarding discriminant validity, a Kruskal-Wallis test was used to analyze PSs and a χ2 test was used for CFs. Mean global rating scale (GRS) scores were compared using an analysis of variance.nnnRESULTSnThe ETI assessment tool had excellent IRR, with an intraclass correlation coefficient of 0.94. There was a significant difference in PSs, CFs, and GRSs (p < 0.05) between cohorts.nnnCONCLUSIONnThe novel field ETI assessment tool has excellent reliability among trained raters and discriminates between experienced ETI providers (EPs) and less experienced ETI performers using PSs, CFs, and GRSs on a fresh cadaveric model.