Paul Cheney

The effect of pH buffering on reducing the pain associated with subcutaneous infiltration of bupivicaine

The authors propose that pH buffering of bupivicaine with sodium bicarbonate reduces the pain associated with its local subcutaneous infiltration. In a double-blind, prospective study, 62 healthy adult volunteers received a 0.5 mL subcutaneous infiltration of 0.5% buffered bupivicaine into the dorsum of a randomly chosen hand. The pH was adjusted to 7.0 by adding 0.05 mL of sodium bicarbonate (1 mEq/L [corrected]) to 10 mL vials of commercially available bupivicaine (1:200 dilution). The control hand was injected with the same amount of unbuffered agent. Pain was scored after each infiltration using a nonsegmented visual analogue scale. Students t-test for paired measurements was used to analyze intergroup pain score differences. Forty-three subjects (69%) reported less pain with buffered bupivicaine and only 17 (27%) noted a modest increase: two subjects (3%) reported no difference. The mean pain score for the buffered agent was 22 mm compared with 30 mm for the control. The mean difference (control-experimental) was 8 mm (t = 4.64, df = 61, P less than .001). The authors conclude that the addition of sodium bicarbonate to bupivicaine reduces the pain associated with its local infiltration.

The Use of Chemical Restraints Reduces Agitation in Patients Transported by Emergency Medical Services

BACKGROUND Agitated patients are the primary source of injury to patients and providers during ambulance transport. OBJECTIVE Our primary hypothesis was that the addition of a chemical restraint agent (midazolam) to a restraint protocol would reduce agitation to a greater extent than a restraint protocol with physical restraint alone. METHODS The local emergency medical services restraint protocol (RP) was implemented on October 1, 2006. It included a form for data collection about each restrained patient. On April 1, 2007, chemical restraint (CR) using midazolam in addition to physical restraints was made available through the RP, and paramedics were educated in its use. Transported patients were divided into pre-CR and post-CR. The post-CR group was split into those who received and those who did not receive midazolam. Agitation was measured on a validated agitation behavior scale with a parametric (Rasch) adjustment. RESULTS There were 96 patients in the pre-CR group and 522 patients in the post-CR group. Forty-three percent of the pre-CR group and 49% of the post-CR group had a decrease in agitation during transport (NS). Of the 522 in the post-CR group, 110 were physically restrained and given midazolam (21%) and 412 were physically restrained without midazolam (79%). There was a significantly greater decrease in agitation scores (-17 ± 21 vs. -7 ± 17) in the subjects receiving midazolam compared to those who did not. CONCLUSION If available, CR is used in about 20% of restrained patients. When CR is used, there is a decrease in the subjects agitation.

Safety and compliance with an emergency medical service direct psychiatric center transport protocol

OBJECTIVES To evaluate compliance and safety of an emergency medical service (EMS) triage protocol that allows paramedics to transport patients directly to psychiatric emergency services. METHODS A psychiatric patient diversion protocol was developed for our system. Protocol compliance was evaluated the following 3 ways: (1) psychiatric facility intake forms completed by mental health workers on patients transported by EMS directly to a psychiatric emergency service (PES) bypassing the ED, (2) hospital records for patients who were redirected from PES to the ED for medical evaluation, (3) retrospective analysis of ambulance charts. Study outcomes included protocol noncompliance rate, protocol failure rate, and any morbidity associated with either noncompliance or protocol failure. Data were analyzed using proportions and 95% confidence intervals (CI). RESULTS A total of 174 patients were directly transported to PES bypassing ED medical clearance. The protocol effectively screened for medical issues in 96% of cases. Protocol noncompliance occurred in 51 cases for a frequency of 29% (CI, 22%-36%). One patient in the paramedic noncompliance group required hospital admission. There was protocol failure in 5 (2.9%; 95% CI, 0.9-6.6) of the patients who fit all protocol requirements for transport to PES but required secondary transport to the ED. All were subsequently transferred back to PES. Nine patients (5.2%; CI, 2.7%-9.5%) required secondary transfer to the ED. No patient had critical or life-threatening problems. CONCLUSIONS Emergency medical service providers showed a poor level of compliance with vital sign criteria, but the protocol provided a high level of safety.

Relationship of Restraint Use, Patient Injury, andAssaults on Ems Personnel

Objective. We hypothesized that the assaults on EMS personnel by patients requiring restraints can be correlated with demographic information, patient condition, andother scene information such as presence the of law enforcement. Methods. The study was a one-year cross-sectional study of paramedic restraint use andassault on EMS personnel in an urban area. A data collection form was completed by EMS for each patient placed in restraints. Study outcome variable was “Assault on EMS personnel.” Predictor variables included demographic andEMS call information, patient condition, law-enforcement related variables, andthe paramedics perception of the need for chemical restraints. To compare predictor andoutcome variables, a multivariable model with odds ratios and95% confidence intervals was used. Results. The study included 271 restrained patients over a 12-month period from April 2002 to April 2003. Seventy-seven (28%) cases were positive for assaults on EMS personnel. Multivariable analysis including 8 variables, indicated the following 6 variables were associated with assault on EMS personnel: time of day between midnight and6 am (OR = 4.4, 95% CI = 1.6–12.7); female patient (OR for males 0.6, 95% CI = 0.3–1.0); violent patient (OR = 10.1, 95%CI = 2.3–48.2); patient injured under supervision (OR = 3.9, 95% CI = 1.1–13.8); arrested patient (OR = 4.4, 95% CI = 1.1–18.5); andperceived need for chemical restraint (OR = 2.1, 95% CI = 1.2–3.9). Conclusion. Multiple factors are correlated with assaults on EMS personnel by patients requiring restraints. By specifically targeting patients exhibiting these factors, EMS providers can help prevent injury to themselves. Patients not exhibiting these factors may be less dangerous.

Impact of a restraint training module on paramedic students' likelihood to use restraint techniques.

Objectives. The purpose of this study was to evaluate a restraint training module for paramedic students. The hypotheses were that the effect of an hour-long restraint training module on paramedic students would (1) improve their understanding of concepts about patient restraints and(2) change their likelihood to use restraint techniques on patients in emergency situations. Methods. This was a cross-sectional study. A five-person panel of highly experienced emergency medical services (EMS) personnel compiled an hour-long restraint training module based on a compiled list of important concepts. A pretest andposttest were designed to contain the following two parts: (1) a knowledge quiz consisting of ten content-based questions and(2) a questionnaire on the likelihood to use restraint techniques in emergency situations, consisting of a five-question validated scale (Video Assessment of Propensity to use Emergency Restraints Scale [VAPERS]). Results. Thirty-four paramedic students at our training institution participated. We found that the paramedic students had a significant increase in their knowledge of the content shown (66% vs. 85%, p < 0.05). There was no significant overall difference between pretest scores on the VAPERS (56 ± 17 on a 0–100 scale) andposttest scores (57 ± 16 on a 0–100 scale). Conclusions. Paramedic students had improved understanding of important restraint concepts following a training module. The training module did not significantly change overall likelihood to use restraint techniques.

Ondansetron Oral Dissolving Tablets are Superior to Normal Saline Alone for Prehospital Nausea

Abstract Background. Antiemetics have been shown to be effective in multiple hospital settings, but few studies have been done in the prehospital environment. Objectives. Our hypotheses were 1) that the amount of normal saline administered during an emergency medical services (EMS) transport was not related to a change in nausea and vomiting and 2) that the addition of the ondansetron orally disintegrating tablet (ODT) would decrease the degree of nausea. Methods. This was a pre–post study of two cohorts of consecutive patients with nausea in the prehospital setting. During phase 1 of the study, our local EMS agency adopted a protocol form to complete whenever a patient with nausea and/or vomiting was assessed and transported to one of the area hospitals. Patients were asked to rate their nausea on a visual analog scale (VAS) and a Likert scale, and saline administration and active vomiting were documented. During phase 2, our EMS system adopted the use of ondansetron ODT for nausea and continued to complete the same forms. The nausea forms completed by EMS during phase 1 (saline only) and phase 2 (ondansetron ODT) were evaluated and compared. For both phases, the primary outcome measures were the change in VAS nausea rating (0 = no nausea, 100 = most nausea imaginable) from beginning to end of the transport and the results on the Likert scale completed at the end of the transport. Relationships were considered significant if p < 0.01. Results. Data were collected from 274 transports in phase 1 and 372 transports in phase 2. The average patient age was 50 ± 12 years. In phase 1 of the study, 178 of 274 patients (65%) received normal saline (mean volume ± standard deviation = 265 ± 192 mL). There was no significant correlation between the VAS change and the amount of fluid administration in either phase of the study. Conversely, during phase 2, patients receiving ondansetron ODT showed significant improvement in both measures of nausea. The difference in nausea improvement between phase 1 and phase 2 was significant (difference in VAS change: 24.6; 95% confidence interval 20.9, 28.3). Conclusion. There was no improvement in patient nausea related to quantity of saline alone during an EMS transport. The addition of ondansetron ODT resulted in a significant improvement in degree of nausea.

Poster 043. Ability of a Priority Dispatch System to Respond Appropriately to Victims of Cardiac Arrest

Purpose: To evaluate die accuracy of die Emergency Medical Priority Dispatch System (EMPDS) with respect to response level for cardiac arrest cases, and to compare response times for delta versus other response levels. The study setting was an urban ALS system that adopted a priority dispatch system 2.5 years ago. The sensitivity of the EMPDS has not been evaluated with regard to cardiac arrest cases since its implementation. We hypothesized that 99% of cardiac arrest cases would receive the highest level of response. Methods: We retrospectively reviewed 1994 emergency medical services (EMS) atraumatic cardiac arrest incident reports. We compared response time to response level using a subsample of 230 cases for which complete data were available. We used ANOVA and chi-square tests in our analyses. Results: Of 284 cardiac arrest cases, 258 (90.8%) were classified as delta, 17 (6.0%) as charlie, eight (2.8%) as bravo, and one (0.4%) as alpha. More cases were misclassified as charlie or lower than expected ( p p = 0.25). Conclusion: The EMPDS has high sensitivity in identifying and responding to cardiac arrest calls. The highest priority calls had, on average, approximately one minute faster response times than the lower priority calls. This reflects the importance of accuracy in this system, particularly with regard to conditions, such as cardiac arrest where response time is highly correlated with survival. The results of this study support the use of the EMPDS, and indicate the need for more specific analyses of the causes and consequences of misclassification of cardiac arrest cases.

Rapid visual colorimetry of peritoneal lavage fluid

STUDY HYPOTHESIS That visual colorimetry can be used to rapidly and precisely estimate the erythrocyte count of 1:5 dilutions of simulated peritoneal lavage fluid. POPULATION Fifty-four normal adult human subjects. METHODS The automated or chamber RBC count is often used on fluid obtained by peritoneal lavage in patients with abdominal trauma to help determine the need for surgery. Unfortunately, this method sometimes results in excessive delay. We designed and built a simple colorimeter that facilitated rapid direct visual comparison of unknown samples with known color standards. A radiograph view box was used as a light source. Standards were prepared in 16-mm glass tubes to simulate peritoneal lavage fluid with RBC counts ranging from 0 to 140,000 in 10,000 cell/microL increments; 1:5 dilutions with water were used throughout to reduce opacity. Thimerosal was added to unknowns and standards to stabilize color; all samples were kept refrigerated at 4 C when not in use. In a double-blind in-vitro study, each subject matched 20 randomly distributed unknowns ranging from 12,000 to 131,000 erythrocytes/microL to the nearest standard. RESULTS The mean absolute error for all 1,080 determinations was 3,560 RBC/microL (95% CI = 4,290-4,830; SD = 4,560; t = 39.6; df = 1,079; P less than .001). This method correctly predicted the RBC count to within 9,000 cells/microL 95% of the time. CONCLUSION Visual comparison of 1:5 dilutions of simulated peritoneal lavage fluid with known color standards can be used to rapidly and precisely estimate the erythrocyte count.