Timothy J. Mader

Reducing the pain of local anesthetic infiltration: Warming and buffering have a synergistic effect

STUDY OBJECTIVE To compare room-temperature unbuffered lidocaine, warm lidocaine, buffered lidocaine, and warm buffered lidocaine to determine which of the four solutions is least painful during infiltration. DESIGN Randomized, controlled, double-blinded, volunteer study. TYPE OF PARTICIPANT Thirty-two young healthy adults. MAIN RESULTS Each subject received four subcutaneous injections of 1% lidocaine: room-temperature unbuffered, warm, buffered, and warm buffered. After each injection, participants recorded their perception of pain associated with infiltration of the solution on a visual analog scale. Mean pain scores for the four solutions were determined and analyzed. The mean perceived pain score for the warm buffered solution was significantly lower than for any of the other solutions (versus warm: P = .0005; versus buffered: P = .0028; versus room temperature: P = .0001). There was no statistically significant difference between either the warm solution or buffered solution and the room-temperature unbuffered lidocaine. The difference in mean pain score for the warm buffered solution, compared with those for the warm, buffered, and room-temperature solutions, suggests that warming and buffering have a synergistic effect. CONCLUSION Skin infiltration with warm buffered lidocaine is significantly less painful than infiltration with room-temperature unbuffered lidocaine, warm lidocaine, or buffered lidocaine.

Emergency Medicine Research Consent Form Readability Assessment

STUDY OBJECTIVE To determine the level of education necessary to understand informed consent documents used to enroll subjects in emergency medicine research. METHODS The directors of 96 accredited emergency medicine residency programs were asked to provide copies of research consent forms approved for patient enrollment at their facilities. A computer program was used to evaluate the readability of the documents submitted. The consent forms were stratified by degree of risk to the subject and compared with the use of ANOVA and the Kruskal-Wallis test. RESULTS Ninety-four informed consent documents were received from 45 program directors. After exclusion of 6 forms, 88 were analyzed using the software program RightWriter 5.0. The mean readability index (years of education needed to understand the content) was 10. The length and complexity of the consent forms increased as risk to the subject increased (P = .03). CONCLUSION Informed consent documents used in emergency medicine research may be too complex for the average patient to understand. A positive correlation exists between protocol risk and consent from complexity.

Adenosine receptor antagonism in refractory asystolic cardiac arrest: results of a human pilot study.

PRIMARY OBJECTIVE To determine if adenosine receptor antagonism has any beneficial impact on victims of asystolic cardiac arrest and whether or not it warrants further clinical study as a treatment for cardiac asystole. MATERIALS AND METHODS A 6-month prospective, randomized, double-blinded, placebo-controlled trial, set in an urban emergency medical services system, in adults with nontraumatic asystolic out-of-hospital cardiac arrest. Patients in whom standard advanced cardiac life support pharmacotherapy failed were randomized to receive placebo or aminophylline, a nonspecific competitive adenosine receptor antagonist. Rhythms were recorded before and after intervention. RESULTS Twenty-two patients were appropriately entered into the trial. Eight patients served as controls and 14 patients received aminophylline. The groups were similar in all measured parameters except for initial rhythm. None of the patients in the placebo group responded to the intervention. Half of the patients in the treatment group had return of organized cardiac electrical activity. CONCLUSION Our results suggest that adenosine receptor antagonism may have a role in the treatment of cardiac asystole. Further clinical studies to validate these findings and clarify the appropriate use of adenosine receptor antagonists in cardiac asystole may be justified.

Time to invasive airway placement and resuscitation outcomes after inhospital cardiopulmonary arrest

BACKGROUND Clinicians often place high priority on invasive airway placement during cardiopulmonary resuscitation. The benefit of early vs. later invasive airway placement remains unknown. In this study we examined the association between time to invasive airway (TTIA) placement and patient outcomes after inhospital cardiopulmonary arrest (CPA). METHODS We analyzed data from the National Registry of Cardiopulmonary Resuscitation (NRCPR). We included hospitalized adult patients receiving attempted invasive airway placement (endotracheal intubation, laryngeal mask airway, tracheostomy, and cricothyrotomy) after the onset of CPA. We excluded cases in which airway insertion was attempted after return of spontaneous circulation (ROSC). We defined TTIA as the elapsed time from CPA recognition to accomplishment of an invasive airway. The primary outcomes were ROSC, 24-h survival, and survival to hospital discharge. We used multivariable logistic regression to evaluate the association between the patient outcome and early (<5 min) vs. later (> or =5 min) TTIA, adjusted for hospital location, patient age and gender, first documented pulseless ECG rhythm, precipitating etiology and witnessed arrest. RESULTS Of 82,649 CPA events, we studied the 25,006 cases in which TTIA was recorded and the inclusion criteria were met. Observations were most commonly excluded for not having an invasive airway emergently placed during resuscitation. The mean time to invasive airway placement was 5.9 min (95% CI: 5.8-6.0). Patient outcomes were: ROSC 50.3% (49.7-51.0%), 24-h survival 33.7% (33.1-34.3%), survival to discharge 15.3% (14.9-15.8%). Early TTIA was not associated with ROSC (adjusted OR: 0.96, 0.91-1.01) but was associated with better odds of 24-h survival (adjusted OR: 0.94, 0.89-0.99). The relationships between TTIA and survival to discharge could not be determined. CONCLUSIONS Early invasive airway insertion was not associated with ROSC but was associated with slightly improved 24-h survival. Early invasive airway management may or may not improve inhospital cardiopulmonary resuscitation outcomes.

A randomized controlled trial of intravenous aminophylline for atropine-resistant out-of-hospital asystolic cardiac arrest.

OBJECTIVES Myocardial ischemia, during cardiopulmonary arrest, can lead to atropine-resistant bradyasystole from interstitial accumulation of endogenous adenosine. Aminophylline is a nonspecific adenosine receptor antagonist capable of reversing ischemia-induced bradyasystole in a variety of settings. The hypothesis of this study was that aminophylline improves the rate of return of spontaneous circulation (ROSC) in atropine-resistant asystolic out-of-hospital cardiac arrest when used early in the resuscitation effort. METHODS This was a prospective, randomized, double-blinded, placebo-controlled trial set in an urban emergency medical services system serving a population of 250,000. All non-pregnant, normothermic adults suffering nontraumatic out-of-hospital cardiac arrest (February 1999 to August 2000) with asystole were eligible. Patients remaining in asystole after initial doses of epinephrine and atropine received either aminophylline 250 mg or matching placebo as a bolus injection through a peripheral intravenous line. All other aspects of the attempted resuscitation proceeded in accordance with standard Advanced Cardiac Life Support (ACLS) guidelines. A sample size of 102 patients was calculated to yield a power of 80% to show an absolute improvement of 25% in ROSC. The aminophylline and control groups were compared by calculating 95% confidence intervals (95% CIs) and the data were modeled using logistic regression. RESULTS The investigators enrolled 112 consecutive patients. One subject was dropped prior to analysis because of missing data. Data for 111 patients were analyzed on an intention-to-treat basis. Baseline characteristics were similar for the two groups. Comparing the control and aminophylline groups, ROSC was achieved in 15.6% (95% CI = 6% to 29%) and 22.7% (95% CI = 13% to 35%), while reversal of asystole occurred in 26.7% (95% CI = 15% to 42%) and 40.9% (95% CI = 29% to 54%), respectively. Group allocation had an odds ratio of 1.8 (95% CI = 0.6 to 5.3) for ROSC. Witnessed arrest was an independent predictor of outcome with an odds ratio of 3.8 (95% CI = 1.3 to 11.2). CONCLUSIONS Addition of aminophylline appears to be a promising new intervention in the ACLS treatment of atropine-resistant asystolic out-of-hospital cardiac arrest.

Aminophylline in undifferentiated out-of-hospital asystolic cardiac arrest

PRIMARY OBJECTIVE To determine if the introduction of intravenous aminophylline, a nonspecific adenosine receptor antagonist, into the resuscitation algorithm of asystole will increase return of spontaneous circulation when used in undifferentiated prehospital cardiac arrest. METHODS An urban, prehospital, prospective, randomized, double-blind, placebo-controlled trial of nonpregnant normothermic adults suffering nontraumatic out-of-hospital asystolic cardiac arrest. Subjects were treated in accordance with published advanced cardiac life support guidelines and standard pharmacotherapy. They were randomly assigned to receive either placebo or aminophylline along with the initial boluses of atropine and epinephrine. Cardiac rhythms and carotid pulses were monitored throughout the resuscitation. RESULTS Eighty-two patients were entered into the trial. Forty-five patients were assigned to the placebo group and 37 received aminophylline. Nine of 45 controls (20%; 95% CI 10-35%) achieved return of spontaneous circulation compared to ten of 37 (27%; 95% CI 14-44%) in the aminophylline group. CONCLUSIONS We were not able to show a statistically significant improvement in return of spontaneous circulation when aminophylline was given during the early resuscitation phase of undifferentiated asystolic cardiac arrest in the prehospital setting with this sample size.

Out-of-hospital cardiac arrest outcomes stratified by rhythm analysis ,

BACKGROUND Survival data for out-of-hospital cardiac arrest (OHCA) victims initially in PEA or asystole who convert to a shockable rhythm during attempted resuscitation, relative to an initial shockable rhythm, have never been previously reported. This study was done to assess OHCA outcomes among a large cohort of adults in the CARES dataset stratified by three rhythm categories: initial shockable (IS), converted shockable (CS), and never shockable (NS). METHODS The study was IRB approved. All adult index events at participating sites (2005-2010) were study eligible. All patient data elements were provided. Odds ratios of CS and NS status for survival to hospital discharge were calculated via multivariate logistic regression that adjusted for demographics, site, resuscitation initiators, AED use, and other covariates. RESULTS There were 40,274 OHCA records submitted to the CARES registry during the study period. After exclusions, our final sample size was 30,939 (7404 IS [23.9%], 3225 CS [10.4%], 20,310 NS [65.7%]). Raw survival rates of CS and NS patients were similar (4.7% vs. 4.1%, respectively; p=0.08) but significantly lower than IS patients (26.9%; p<0.001). The adjusted OR of survival to hospital discharge for CS was 0.17 (95% CI: 0.14, 0.20) and for NS it was 0.17 (95% CI: 0.15, 0.18) with IS as the referent. CONCLUSION After OHCA, the survival rate for CS victims is significantly lower than for IS patients. These findings suggest that CS and IS are different entities and that alternatives to existing resuscitation algorithm tailored to patients with CS should be investigated.

Survival from profound alcohol-related lactic acidosis.

We present the case of a patient with profound alcohol-related lactic acidosis (lactate = 16.1 mmol/L; pH = 6.67) associated with a multitude of metabolic derangements who made a remarkable recovery following aggressive management. The patient was in extremis upon arrival in the emergency department (ED), and resuscitation was begun immediately. While in the ED, the problem list generated included: acute alcohol intoxication, severe lactic acidosis, dehydration, hypothermia, hypoglycemia, acute renal insufficiency, and hepatic failure. Resuscitation continued in the intensive care unit with remarkable improvement and satisfactory outcome. In this patient, the severe lactic acidosis and associated abnormalities were all attributed to acute and chronic effects of ethanol. A brief summary of the proposed mechanism by which these metabolic derangements developed and an outline of her management follows.

Acute pancreatitis in children.

Acute pancreatitis in childhood is not a rare condition, and it should be considered in all children presenting with acute abdominal complaints. A complete history should be obtained, with emphasis on recent trauma or infection, current medications, and the presence of any chronic diseases. After a thorough physical examination, simple ancillary studies including noninvasive imaging techniques will confirm the clinical suspicion. Appropriate aggressive treatment, instituted early, will help to reduce the associated morbidity and mortality. Most children with acute pancreatitis will recover with conservative management and suffer no significant long-term sequelae.

Factors Associated With Longer Time to Treatment for Patients With Suspected Acute Coronary Syndromes A Cohort Study

Background—Rapid treatment of acute coronary syndromes (ACS) is important; causes of delay in emergency medical services care of ACS are poorly understood. Methods and Results—We performed an analysis of data from IMMEDIATE (Immediate Myocardial Metabolic Enhancement during Initial Assessment and Treatment in Emergency Care), a randomized controlled trial of emergency medical services treatment of people with symptoms suggesting ACS, using hierarchical multiple regression of elapsed time. Out-of-hospital ECGs were performed on 54 230 adults calling 9-1-1; 871 had presumed ACS, 303 of whom had ST-segment elevation myocardial infarction and underwent percutaneous coronary intervention. Women, participants with diabetes mellitus, and participants without previous cardiovascular disease waited longer to call 9-1-1 (by 28 minutes, P<0.01; 10 minutes, P=0.03; and 6 minutes, P=0.02, respectively), compared with their counterparts. Time from emergency medical services arrival to ECG was longer for women (1.5 minutes; P<0.01), older individuals (1.3 minutes; P<0.01), and those without a primary complaint of chest pain (3.5 minutes; P<0.01). On-scene times were longer for women (2 minutes; P<0.01) and older individuals (2 minutes; P<0.01). Older individuals and participants presenting on weekends and nights had longer door-to-balloon times (by 10, 14, and 11 minutes, respectively; P<0.01). Women and older individuals had longer total times (medical contact to balloon inflation: 16 minutes, P=0.01, and 9 minutes, P<0.01, respectively; symptom onset to balloon inflation: 31.5 minutes for women; P=0.02). Conclusions—We found delays throughout ACS care, resulting in substantial differences in total times for women and older individuals. These delays may impact outcomes; a comprehensive approach to reduce delay is needed.