The emergency department care of hemodialysis patients.

AIMS: To describe the emergency department (ED) presentation, evaluation and disposition of maintenance hemodialysis (HD) patients. MATERIALS AND METHODS: A retrospective review of adult HD patients seen 1/1-12/31/97. The following was collected: demographics, mode of arrival, chief complaint, etiology of renal failure, evaluation, treatment, disposition, length of stay and facility charges. During the study period, this tertiary care ED had an annual adult census of 45,000. No clinical pathways were in place. RESULTS: 143 patients made 355 visits: 351 charts were available. Mean patient age was 51 (range 20-86), 62% were male, 51% were white. 70% presented from home, 26% from dialysis. EMS transported 32%. Medicare insured 78%. Etiologies of renal failure included hypertension (33%), diabetes (27%), HIV (7%) and glomerulonephritis (8%). Complaints were related to infection (18%), dyspnea (17%), vascular access (16%). chest pain or dysrhythmia (15%) and gastrointestinal complaints (12%). ED evaluation included CBC (79%), electrolytes (75%), CXR (57%) and EKG (48%). Antibiotics were administered to 21%. HD was performed earlier than scheduled in 14%. Two hundred and eighteen patients (62%) were admitted (ICU 11%, telemetry 22%), 19 (5%) refused admission and 2 expired in the ED. The average hospital length of stay was 7.8 days (range 1-59), with 29% hospitalized more than 1 week, compared to 6.54 days for non-HD patients. The mean facility charge for admitted subjects was $14,758, while the average cost for non-HD admissions was $7,152. Of the 133 patients (38%) who were discharged directly from the ED, the mean length stay was 223 minutes (range 30 to 750) and the mean charge was $658. The mean length of stay for non-HD patients was 124 minutes. CONCLUSION: The ED evaluation of adult HD patients involves multiple diagnostic modalities, and patients are usually admitted. The admit rate, ED length of stay for discharged patients and hospital charges for care were substantially higher in the HD patients than in the general population. Further research in the ED care of these complex patients should be undertaken.

Benzyl alcohol with epinephrine as an alternative to lidocaine with epinephrine.

A randomized, prospective, double-blind study comparing benzyl alcohol with epinephrine, 1:100,000 (BA), and lidocaine with epinephrine, 1:100,000 (LID), as local anesthetics was carried out on adult patients with simple lacerations. The two study groups were compared for pain of infiltration (100 mm visual analog scale) and need for additional anesthesia. Pain scores were compared by a Mann Whitney Independent Rank Sum test and need for additional anesthesia by a Fishers Exact test. A total of 52 subjects (26 per group) were analyzed. The groups were similar in demographics and wound characteristics. The median pain score for BA, 7.5 mm, was less than for LID, 19.5 mm (p = 0.049). Although more patients receiving BA required additional anesthesia as compared to LID (8/26 versus 2/26), this difference did not reach statistical significance. BA is a reasonable alternative local anesthetic to LID for patients who are allergic to LID.

Home antipyretic use in children brought to the emergency department.

OBJECTIVE: To determine how often children with a complaint of fever receive antipyretics at home and if any demographic factors are associated with correct dosing. METHODS: A prospective, descriptive study of children 3 to 36 months old presenting with complaint of fever was conducted. Caregivers were questioned about demographics and antipyretic given. The ability of demographics to predict proper dosing was tested first individually and then with a regression model. The effect of proper home dosing on presence of fever and height of fever was also analyzed. A total of 138 children were analyzed. RESULTS: Of the 118 (86%) who received antipyretics at home, only 47% had been given a proper dose. No demographic variable predicted proper dosing. CONCLUSION: Reported antipyretic dose at home did not predict presence of fever or height of temperature measured in the emergency department.

Nitrous oxide for the treatment of acute migraine headache.

The objective of this study was to determine the efficacy of nitrous oxide in the therapy of acute migraine symptoms in emergency department (ED) patients. This was a prospective, randomized, double blind study of patients presenting to an ED. All eligible patients had a prior diagnosis and symptoms consistent with migraine headache and a normal neurological examination. Patients were randomized to receive either 50% nitrous oxide and 50% oxygen or 100% oxygen over 20 minutes. All patients completed a visual analog pain scale before and immediately after intervention. Initial pain scores and change in pain scores between the two groups were compared. There were 22 patients enrolled, 10 in the nitrous oxide group and 12 in the oxygen group. The groups were similar in age, gender, duration of headache, and initial pain scores. Pain scores decreased significantly in the nitrous oxide group (median change, 69 to 21 mm, P = .02). The oxygen group did not show significant change in pain scores (median change, 78.5 to 72, P = .09). Eighty percent of patients receiving nitrous oxide required no rescue medication at the completion of the intervention, compared with 17% of those receiving 100% oxygen (P = .008). Twenty minutes after termination of intervention, 60% of patients who had received nitrous oxide still required no rescue medication, compared with 8% of those who had received 100% oxygen (P = .02). Nitrous oxide shows efficacy in ED short-term treatment of acute migraine headache.

Accuracy of an enzymatic assay device for serum ethanol measurement.

OBJECTIVE: To determine the accuracy of an enzymatic assay of serum to measure blood ethanol levels in the emergency department. METHODS: A blinded, prospective study of emergency department patients for whom a blood ethanol was ordered and performed. After skin prep with betadine, two blood samples were drawn into separate sodium fluoride-containing vacutainers. One sample was sent to the hospital laboratory for blood ethanol analysis. The other was centrifuged for 5 minutes and the serum was then assayed using the QED A350 Saliva Alcohol Test. Values were then compared by kappa statistic and Pearson's correlation. Sensitivity and specificity calculations were determined for the QED device to detect a blood ethanol > 100 mg/dL. RESULTS: Sixty-six patients were enrolled. The kappa value for QED compared to lab blood ethanol was 0.93. The Pearson's correlation coefficient was 0.94. The QED, in general, tended to overestimate blood ethanol slightly. The QED was 100% sensitive and 82% specific in detecting a blood ethanol > 100 mg/dL. CONCLUSIONS: Analysis of serum using a QED A350' is a sensitive and accurate index of low to moderate increases in blood ethanol appropriate to emergency department, but not legal, interpretation.

Randomized trial of diphenhydramine versus benzyl alcohol with epinephrine as an alternative to lidocaine local anesthesia.

STUDY OBJECTIVES: We compared the pain of infiltration and anesthetic effects of.9% benzyl alcohol with epinephrine, 1% diphenhydramine, and.9% buffered lidocaine. METHODS: A prospective, randomized, double-blind study comparing benzyl alcohol, diphenhydramine, and lidocaine was carried out on adult volunteers. Each subject received all 3 injections in a standardized manner. Pain of infiltration was measured on a 100-mm visual analog pain scale and analyzed with a Kruskal-Wallis test. Duration of anesthesia was assessed at 5-minute intervals for a maximum of 45 minutes and compared with the use of survival analysis techniques by a log-rank test. Return of sensation by 45 minutes was evaluated with an exact chi2 test. All tests were 2-tailed, with significance defined as P <.05. RESULTS: Thirty subjects were enrolled. The diphenhydramine median pain score was 55 mm, compared with 12.5 mm for lidocaine and 5 mm for benzyl alcohol (P =.001). Pairwise comparisons showed that all possible combinations were statistically significant. The 3 anesthetics were different with respect to duration of anesthesia (P <.001). Pairwise comparisons revealed a longer duration of anesthesia for lidocaine than for diphenhydramine or benzyl alcohol, but no significant difference was found between diphenhydramine and benzyl alcohol. Pain sensation returned within the 45-minute study period in only 3 of 30 lidocaine injections, compared with 11 of 30 benzyl alcohol injections and 19 of 30 diphenhydramine injections (P =.001). CONCLUSION: Benzyl alcohol is a better alternative than diphenhydramine as a local anesthetic for lidocaine-allergic patients.

Local anesthesia for lacerations: pain of infiltration inside vs outside the wound.

OBJECTIVE: To compare the pains of infiltration of a local anesthetic for simple lacerations when used from within the wound vs through intact skin. METHODS: A randomized, prospective, single-blind, experimental protocol was conducted on a convenience sample of adults with simple lacerations. Subjects received two 0.5-mL injections of buffered lidocaine in each of the sites being compared. Immediately following each injection, pain was measured using a visual analog pain scale. Pain scores were converted to a numerical score and analyzed by a Wilcoxon signed-rank test. Subjects also were asked which injection hurt more, the first or the second (analyzed by a chi2 test). RESULTS: A total of 63 subjects were enrolled. The first injection was within the wound and the second injection through intact skin (group 1) for 32 patients, and the order was reversed for 31 patients (group 2). Median pain scores for all inside-the-wound injections (14 mm) were lower than those with intact skin injections (37 mm; p < 0.0001). In group 1, 4 subjects reported the first injection (within wound) hurt most, 23 thought the second (intact skin) hurt most, and 5 found no difference. In group 2, 18 subjects reported the first injection (intact skin) hurt most, 5 believed the second injection (within wound) hurt most, and 8 found no difference, p < 0.0001. CONCLUSION: Local anesthesia is less painful when injected from within a laceration as compared with intact skin.

The effect of order on pain of local anesthetic infiltration.

OBJECTIVE: To define the relationship between order of injection and pain of infiltration of buffered lidocaine. METHODS: Volunteers > or = 18 years of age were enrolled in a prospective, double-blind experimental protocol. Subjects received a 0.5-mL intradermal injection of anesthetic in each forearm. All injections were given by the same individual in the same manner. Immediately following each injection, the subjects rated the pain of infiltration on a standardized 100-mm visual analog pain scale. Both the subjects and the individual giving the injections were blinded to the anesthetic being administered. They were told that the injections could be either plain or buffered lidocaine. They were further informed that any individual subject could receive 2 of the same anesthetics or 1 of each in either order. In reality, all injections were buffered lidocaine for all subjects. Pain scores were converted to a numerical score by making measurements to the nearest millimeter and analyzed by a Wilcoxon signed-rank test with p < 0.05 considered significant. RESULTS: Fifty subjects were enrolled. The first injection had a median pain score of 13.5 mm, compared with 23.5 mm for the second (p = 0.007). CONCLUSION: The second injection of buffered lidocaine was found to be statistically more painful than the first in this protocol that controlled for all variables except for order of injection. Future studies involving paired comparisons should take this information into account.

Topical tetracaine attenuates the pain of infiltration of buffered lidocaine.

OBJECTIVE: To determine whether topical tetracaine attenuates the pain of buffered lidocaine infiltration. METHODS: A prospective, randomized, double-blind trial was conducted involving adults with lacerations being repaired following local anesthesia. Two 0.5-mL injections of buffered lidocaine were given in a standardized manner. Injection 1 was given prior to application of topical study solution. Injection 2 was given on the opposite side of the laceration after topical application of a study solution that was 4 mL of either tetracaine or normal saline. Pain of each infiltration was measured using a visual analog pain scale. Pain score differences (injection 1 - injection 2) were compared for the 2 study solutions using a Wilcoxon 2-sample signed-rank test. RESULTS: Of 57 subjects studied, 29 received tetracaine and 28 received saline. The groups were similar in age, gender, wound length, wound location, and initial pain score. Pain scores decreased significantly in the tetracaine group as compared with the saline group. The median pain score difference for tetracaine was 12.0 mm, with an interquartile range (IQR) of 2 to 43 mm, as compared with 2 mm, with an IQR of - 17 to 21 mm for saline (p = 0.048). CONCLUSION: Topical tetracaine attenuates the pain of infiltration of buffered lidocaine.

Safe out-of-hospital treatment of chest pain without direct medical control.

INTRODUCTION: The use of direct medical control (DMC) in the out-of-hospital setting often is beneficial, but has the disadvantage of consuming emergency medical services (EMS) resources. HYPOTHESIS: Uncomplicated, nontrauma, adult patients with chest pain can be treated safely and transported by paramedics without DMC. METHODS: Retrospective chart review of all nontrauma, adult patients with chest pain treated in a combined rural and suburban EMS system during a 2-year period (December 1990 through November 1992) was conducted. Before November 1991, DMC was mandatory for all patients with chest pain. Beginning 01 November 1991, if a patient had resolution of a pain either spontaneously, with administration of oxygen, or after a single dose of nitroglycerin, DMC was at the discretion of the paramedic. Using the above criteria for inclusion, three study groups were defined: Group 1, before protocol change; Group 2, after protocol change without DMC; and Group 3, after protocol change when physician contact was obtained, but not required. These groups were compared for the following parameters: 1) scene time; 2) time to administration of first dose of nitroglycerin; 3) time interval between measurement of vital signs; 4) oxygen use; 5) intravenous access; and 6) electrocardiographic monitoring. Continuous and categorical variables were analyzed by multivariate and univariate analysis of variance and chi-square tests, respectively. RESULTS: Of 308 nontrauma, adult patients with chest pain, 71 met inclusion criteria in Group 1, 40 in Group 2, and 34 in Group 3. No statistically significant differences were identified in any of the study parameters. CONCLUSION: Adult patients with chest pain who have no other symptoms or complicating conditions can be treated appropriately be paramedics without DMC.

Lack of a hyperkalemic response in emergency department patients receiving succinylcholine.

OBJECTIVE: To determine whether serum potassium (K) levels increase significantly following succinylcholine (SCh)-assisted intubation in ED patients. METHODS: A prospective, noncontrolled, consecutive case series design was used to evaluate the change in serum K levels in ED patients who received SCh for emergency intubation. The study was performed at an academic medical center staffed by board-certified emergency physicians. The subjects were 100 consecutive prescreened ED patients with various diagnoses who received SCh for intubation. The eligible subjects had serum K levels determined prior to and 5 minutes after administration of a 1.0-1.5-mg/kg i.v. dose of SCh. Serum K levels were measured by the ion-selective electrode assay method. RESULTS: The mean change in serum K levels was -0.04 mmol/L (95% CI -0.14 to 0.06). The maximum increase was 1.10 mmol/L. The serum K level rose in 46 cases, decreased in 46 cases, and was unchanged in eight cases. No instance of SCh-induced cardiac arrest was identified. CONCLUSION: Changes in serum K levels following SCh administration in prescreened ED patients were minimal. A hyperkalemic response is uncommon in ED patients who undergo SCh-assisted intubation.

The effects of warming and buffering on pain of infiltration of lidocaine.

OBJECTIVES: To investigate the effects of warming vs buffering, and warming with buffering, on the pain of lidocaine infiltration. METHODS: A randomized, double-blind clinical trial was conducted using volunteers aged 18 years or more and without an allergy to lidocaine. The study consisted of two parts, each comparing two solutions. The solutions for Part I were warm (38.9 degrees C; 102 degrees F) plain lidocaine and room-temperature buffered lidocaine. Warm buffered lidocaine and room-temperature buffered lidocaine were used for Part II. The subjects received two standardized 0.5-mL intradermal injections, one study solution in each forearm. Immediately after each injection, pain was assessed using a 100-mm visual analog pain scale. Pain scores were analyzed by the sign test, with significance defined as p < 0.05. RESULTS: Part I (n = 10): Nine subjects reported room-temperature buffered lidocaine to be less painful than warm plain lidocaine. Mean pain scores were 28 mm lower for room-temperature buffered lidocaine than they were for warm plain lidocaine (p < 0.01). Part II (n = 24): Eleven subjects found warm buffered lidocaine to be the least painful, 11 reported room-temperature buffered lidocaine to be the least painful, and two reported no difference. A mean pain score difference of 2.1 mm favoring warm buffered lidocaine was not statistically significant. Part II had a power of 80% to detect a 10-mm difference between the two solutions at alpha = 0.05. CONCLUSION: To reduce the pain of lidocane infiltration, buffering is more effective than warming. Warming does not enhance buffering.

Does topical lidocaine attenuate the pain of infiltration of buffered lidocaine?

OBJECTIVE: To determine whether topical lidocaine attenuates the pain of buffered lidocaine infiltration. METHODS: This was a prospective, randomized, double-blind, placebo-controlled trial conducted at a university-based ED. The subjects were adults who had lacerations being repaired using local anesthesia. Two 0.5-mL injections of buffered lidocaine were given in a standardized manner. The first was given prior to application of topical study solution. The second was given on the opposite side of the laceration after topical application of study solution, which was 5 mL of either 2% lidocaine or saline placebo. The pain of each infiltration was measured using a visual analog pain scale. Pain scores were calculated and compared using a Wilcoxon test with significance defined as p < or = 0.05. RESULTS: A total of 54 subjects participated; 29 received lidocaine topically and 25 received placebo. The groups were similar with respect to age, gender, wound length, wound location, and initial pain score. Pain scores decreased by 11.6 +/- 18.6 mm for lidocaine and 10.9 +/- 20.9 mm for placebo (p > 0.5). The study had the power to detect a 15-mm pain score difference (alpha = 0.05 and beta = 0.20) on a 100-mm scale. CONCLUSION: Topical 2% lidocaine does not attenuate the pain of infiltration of buffered lidocaine more than does topical normal saline. Investigation of other topical anesthetics with and without epinephrine in conjunction with buffered lidocaine is warranted.

Ketorolac tromethamine use in a university-based emergency department.

OBJECTIVE: To assess the use of parenteral ketorolac tromethamine (KT) in the emergency department (ED). METHODS: During a six-month period, KT was administered in an uncontrolled, nonblinded fashion to a series of ED patients experiencing acute pain. The patients rated pain on a previously validated visual analog pain scale before receiving KT. They repeated this procedure one hour after KT administration, prior to additional analgesia, or preceding release, whichever came first. Analgesic response was assessed by comparing pretreatment and posttreatment pain scores for the entire study population by the Wilcoxon rank sum test. Possible effects of specific variables (patient age, gender, race, indication for KT, route, dose, previous use of NSAIDs, and concurrent administration of muscle relaxants) were assessed using the Kruskal-Wallis test. RESULTS: Of the 445 patients enrolled, 375 (84%) reported pain relief with KT, only seven (2%) worsened, and the remainder (14%) reported no change. Overall pain reduction was 37.6 +/- 27.2 (SD) mm (100-mm scale) for the entire study population. The pain scores obtained after KT administration were significantly lower than those obtained prior to KT administration (p < 0.001). The only variable that significantly influenced pain score reduction was indication for KT (p = 0.001). Nephrolithiasis and toothache patients had the largest mean reductions in pain. No significant side effect was reported. CONCLUSION: Parenteral KT is a useful and safe analgesic for ED patients. The agent generally provides analgesia and is particularly promising for patients with nephrolithiasis or toothache.

A comparison of proparacaine and tetracaine eye anesthetics.

OBJECTIVE: To compare two topical eye anesthetics, proparacaine and tetracaine, for pain of instillation and duration of activity. METHODS: Volunteers received both anesthetics in a prospective, randomized, double-masked protocol. The subjects were given one drop of a study solution in the lower lid fornix of the left eye. Immediately after receiving the medication, they rated the pain of instillation on a previously validated visual-analog pain scale. This procedure was then repeated in the right eye with the other study solution. Pain scales were quantified by making measurements to the nearest millimeter from the point of scale origin to the point marked by the patient. The time interval until return of the corneal blink reflex was determined using a cotton wisp. Pain scores and the time to return of corneal reflex were analyzed by the Sign test and Wilcoxon rank-sum test, respectively, with significance defined as p < 0.05. RESULTS: Twenty-three subjects were available for analysis. Twenty subjects reported proparacaine hurt less than tetracaine, two felt the pain was the same for the two agents, and only one reported that proparacaine was more painful. The mean pain score for tetracaine was 24 mm (100 mm maximum) higher than that for proparacaine (p < 0.0002). Proparacaine lasted 1.3 minutes longer than tetracaine, 10.7 minutes versus 9.4 minutes (p = 0.0001). CONCLUSION: Proparacaine eye drops cause less pain than tetracaine eye drops upon instillation. Anesthesia from proparacaine last slightly longer. These properties make proparacaine preferable to tetracaine.

4-Methylpyrazole blocks acetaminophen hepatotoxicity in the rat.

STUDY OBJECTIVE: To determine whether 4-methylpyrazole inhibits the hepatotoxic effects of acetaminophen in a rat model. DESIGN AND TYPE OF PARTICIPANTS: A nonblinded experiment using male Sprague-Dawley rats. INTERVENTIONS: Animals were divided into four groups. Groups 1 through 3 received 2,000 mg/kg acetaminophen by gavage; group 4 acted as a control. At four or eight hours, group 2 received 400 mg/kg 4-methylpyrazole; group 3 received 50 mg/kg 4-methylpyrazole. Blood samples were taken for measurements of serum AST and ALT levels. Livers were removed for microscopic examination and grading of necrosis. RESULTS: Lower AST and ALT levels were obtained for both the 400-mg/kg (P < .01) and 50-mg/kg (P < .05) doses of 4-methylpyrazole administered four hours after acetaminophen. Although mean AST and ALT levels also were lower when 400 and 50 mg/kg 4-methylpyrazole were administered eight hours after acetaminophen, these results were not statistically significant. Median necrosis scores were 3 for rats receiving acetaminophen alone, 0.5 for those receiving acetaminophen and 400 mg/kg 4-methylpyrazole (P < .05), 1 for those receiving acetaminophen and 50 mg/kg 4-methylpyrazole (P < .05), and 0 for control rats (P < .05). CONCLUSION: When administered four hours after a toxic dose of acetaminophen, 4-methylpyrazole significantly inhibits hepatotoxicity in the rat, as reflected by lower levels of serum transaminases and lesser degrees of hepatic necrosis.