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Biomedical subjects

W A Watson

Publications and source records attributed to W A Watson.

At least 19 recordsLinked to original sources
PubMed1992

Foreign body retention in glass-caused wounds.

STUDY OBJECTIVE: To describe patient and wound characteristics that are clinically useful in identifying wounds that were caused by glass and retained a foreign body. DESIGN: Retrospective consecutive case review. SETTING: Urban, university-affiliated teaching hospital. TYPE OF PARTICIPANTS: Four hundred thirty consecutive patients with a total of 578 evaluable wounds caused by glass during a 12-month period. MEASUREMENTS AND RESULTS: Medical records were reviewed to determine patient demographics, primary wound data (eg, location, type, description), mechanism of injury, type of glass involved, and presence of foreign body sensation. Glass was found by examination in 7% of wounds. Eight percent of 137 radiographs were positive. Wounds with the highest prevalence of retained glass were puncture wounds (P < .0005), those caused by stepping on glass or by a motor vehicle accident (P < .005), and those of the head or foot (P < .003). CONCLUSION: Characteristics of wounds most likely to retain glass were identified in this retrospective study. The presence of these factors should increase the clinician's suspicion of a retained glass foreign body. The indications for radiography for the detection of retained glass in wounds should be clarified with prospective studies.

Adult↗
PubMed1992

Emergency department interpretation of electrocardiograms.

STUDY OBJECTIVE: To determine the concordance of emergency physicians' and cardiologists' interpretations of abnormal ECGs. DESIGN: Retrospective cohort study. SETTING: An urban teaching hospital emergency department. TYPE OF PARTICIPANTS: Patients with an abnormal ED ECG that was interpreted by both an emergency physician and a cardiologist and who were discharged from the ED. MEASUREMENTS AND MAIN RESULTS: Seven hundred sixteen ECGs were reviewed; 143 abnormal ECGs were obtained on patients discharged from the ED. The cardiologist's final interpretation was defined as correct, and discordance was any abnormality not identified by the emergency physician. The overall discordance between emergency physicians' and cardiologists' ECG interpretations was 58.0% (P less than .001). Twenty-five discordant interpretations were likely clinically significant--representing missed ischemia, infarct, and abnormal rhythm. There was no ED interpretation in three of these. The most frequently missed findings by emergency physicians were evidence of ischemia/infarct of the anterior wall and atrial fibrillation. Twenty-one of the 83 patients with discordant interpretations were lost to follow-up. Two cases had a clinically significant discrepancy that would have altered patient care. CONCLUSION: Although the overall discordance was more than 50%, most ED misinterpretations were determined unlikely to have clinical significance. Additional studies are needed to identify variables that contribute to ED ECG misinterpretation and to develop methods to resolve these difficulties.

Cardiology↗
PubMed1992

Naloxone-associated patient violence: an overlooked toxicity?

OBJECTIVE: To report two cases of a previously unreported adverse effect, violent patient behavior, after the reversal of sedation by intravenous naloxone. DESIGN: Case report. PATIENTS/INTERVENTIONS: Responses of two individuals who had reversal of sedation by intravenous naloxone are compared. RESULTS: Placement of patient restraints before the administration of intravenous naloxone to obtunded or unconscious patients can make an important contribution to the safety of patients, healthcare personnel, and public safety personnel, as illustrated by the violent reaction of one unrestrained patient after naloxone administration. CONCLUSIONS: Patient restraint should be considered before naloxone administration to protect the patient and healthcare workers. In the prehospital setting, limiting the use of naloxone to patients with decreased mental status and respiratory depression would decrease the likelihood of naloxone-induced violent behavior.

Adult↗
PubMed1992

The preadministration of activated charcoal and aspirin absorption.

There is little information describing the effects of activated charcoal preadministration on drug absorption. This study was undertaken to determine the effect of activated charcoal preadministration at two different times on aspirin absorption. Fifteen volunteer subjects completed three study phases: 1) 975 mg aspirin alone, 2) 975 mg aspirin 30 min after 10 g activated charcoal, and 3) 975 mg aspirin 60 min after 10 g activated charcoal. Urine was collected for 48 h after the initiation of each study phase, and total aspirin recovery determined by HPLC. The aspirin recovery was 88.8% +/- 4.5% for the control phase, and 84.8% +/- 9.4% (Phase 1) and 85.8% +/- 12.6% (Phase 2) for the activated charcoal treatments (p > 0.05). These results suggest that activated charcoal administered 30 and 60 min prior to drug ingestion has little effect on drug absorption. Further studies of the effect of charcoal preadministration on the absorption of other drugs may provide useful information regarding factors important in determining activated charcoal efficacy.

Absorption↗
PubMed1992

A longitudinal analysis of factors associated with morbidity in cocaine abusers with psychiatric illness.

We conducted a study to characterize a population of cocaine users who were referred to a state psychiatric institution, identify treatment problems including reasons for relapse, and develop strategies to improve treatment outcome. Using a data base system from a tertiary-care hospital emergency department, we identified a sample of 80 patients with a cocaine-related presentation who came to the emergency department and were referred to the psychiatric facility. Forty-six percent had consumed crack cocaine, and 65% reported ingesting cocaine with other drugs, half of them with alcohol. Suicidal ideation or attempt was the most common reason for referral. A retrospective review of 58 of the 80 referrals to the psychiatric facility showed that over half of the patients were given a concurrent psychiatric diagnosis and required hospitalization on an acute-care psychiatric unit. Sixty-two percent of those admitted had prior hospitalizations at the psychiatric facility, yet only five patients had received treatment for substance abuse. Seventy-four percent were readmitted to the psychiatric facility within 1 year of their index episode, with a higher rate of relapse among persons with dual diagnoses compared to cocaine users without dual diagnoses (p less than 0.05). Possible reasons for relapse included lack of referral for substance abuse treatment, nonintegrated treatment of psychiatric illness and substance abuse, lack of psychosocial support, and unresolved financial or job-related stressors. The data support increased funding to facilities that treat persons with dual diagnoses, and suggest the need to develop comprehensive treatment approaches involving a multidisciplinary team to address issues of mental illness and substance abuse concomitantly, and to identify and resolve stressors leading to relapse.

Adult↗
PubMed1992

Alcohol and motorcycle riders: a comparison of motorcycle and car/truck DWIs.

Alcohol's effects on balance and motor coordination would be expected to have greater consequences for motorcycle riders than car/truck drivers. Driving while intoxicated/under the influence (DWI) reports for 1984 and 1985 from the San Antonio, TX, Police Department were reviewed to evaluate motorcycle DWIs, and to compare them with car/truck DWIs. During the 2-y period there were 100 DWI reports involving motorcycle riders, which were compared to 100 involving car/truck drivers. Motorcycle riders were all male and younger (mean 26 y) than car/truck drivers (p less than 0.05). Initiation of the DWI investigation of motorcycle riders was more frequently due to excessive speed, and less likely due to an accident, when compared to car/truck investigations. Breath alcohol testing demonstrated a significantly lower blood alcohol concentration in motorcycle riders, 0.14 +/- 0.05 g/dL, than in car/truck drivers, 0.16 +/- 0.05 g/dL (p = 0.016). The results of this study suggest that alcohol influences motorcycle riders to a greater extent than it does car/truck drivers. Further data is needed to determine whether lower blood alcohol concentration limits should be considered for the definition of "driving while impaired" in motorcycle riders.

Alcoholic Intoxication↗
PubMed1991

Effect of standing orders on paramedic scene time for trauma patients.

STUDY OBJECTIVE: To determine if a protocol change that allowed paramedics to perform certain procedures before base station contact (standing orders) would decrease scene time in trauma patients. DESIGN: Retrospective review of case series. SETTING: A single-tiered, all advanced life support emergency medical services system. INTERVENTION: Implementation with standing orders for invasive procedures. TYPE OF PARTICIPANTS: All physiologically unstable trauma patients transported to a Level I trauma center by ambulance. MEASUREMENTS AND MAIN RESULTS: One hundred ninety-seven patients met the inclusion criteria--87 before and 110 after the initiation of standing orders. Mean scene times for the control group (15.3 +/- 8.4 minutes) and for the standing orders group (15.1 +/- 7.6 minutes) were similar (P = .18). The power of the study to detect a two-minute difference in scene time was .92. Scene time was not influenced by mechanism of injury, and the number of procedures performed on patients was similar between the two groups. CONCLUSION: Standing orders did not decrease scene time in physiologically unstable trauma patients. Further study is necessary to delineate the factors that actually contribute to on-scene time and the factors that are important in determining whether standing orders or on-line medical contact should be used.

Adult↗
PubMed1991

Simulated acetaminophen overdose: pharmacokinetics and effectiveness of activated charcoal.

STUDY OBJECTIVE: To determine the absorption rate of a supratherapeutic dose of acetaminophen elixir and compare the effect of activated charcoal (AC) given at different time intervals on preventing acetaminophen absorption. DESIGN: Randomized, nonblinded, crossover controlled study. SETTING: A certified regional poison control center. PARTICIPANTS: Ten healthy, adult male volunteers from 21 to 39 years old. INTERVENTIONS: Each subject received 5 g acetaminophen (elixir) on four occasions: a control phase plus 30 g of AC administered 15, 30, or 120 minutes after acetaminophen. Serum acetaminophen levels were obtained during the control phase only, and 24-hour urine collections were obtained during all four phases. MEASUREMENTS AND MAIN RESULTS: The highest serum acetaminophen levels were measured 1.4 +/- 0.52 hours after ingestion, and absorption was 97% complete by a mean of 2.05 hours. The administration of AC at 15, 30, and 120 minutes after acetaminophen reduced urinary recovery of acetaminophen and metabolites by 48%, 44%, and 33%, respectively. CONCLUSION: AC significantly reduces urinary recovery but not absorption of acetaminophen when administered two hours after acetaminophen elixir.

Acetaminophen↗
PubMed1991

Sulfate homeostasis. III. Effect of chronic naproxen or sulindac treatment on inorganic sulfate disposition in arthritic patients with renal impairment.

The purpose of the present investigation was to examine the influence of chronic naproxen (500 mg twice daily) or sulindac (200 mg twice daily) therapy on the disposition of inorganic sulfate in arthritic subjects with impaired renal function. Subjects were studied during a control period (after a 7-day NSAID washout) and after 14 days of treatment with either naproxen or sulindac. During the control period subjects in this investigation exhibited higher serum sulfate concentrations and lower sulfate renal clearance values than reported for younger subjects with normal renal function. Treatment with either sulindac or naproxen significantly decreased creatinine clearance. Sulindac therapy also increased the serum sulfate concentration and decreased the clearance of sulfate; a similar trend was observed after naproxen therapy but the average change was smaller and not statistically significant. There were significant correlations between the creatinine and the sulfate clearances or serum concentrations. The glomerular filtration rate of inorganic sulfate was not altered by drug treatment and there was no impairment of reabsorption. The serum concentrations and renal clearance of other electrolytes (sodium, potassium, magnesium, calcium, phosphorus) were largely unaffected. Therefore, chronic treatment with naproxen or sulindac decreases the renal clearance of endogenous sulfate in humans: this appears to be a consequence of the decrement in renal function observed in subjects with preexisting mild renal impairment.

Aged↗
PubMed1991

Lidocaine absorption and metabolism after oropharyngeal application in young and young-elderly adults.

The purpose of this study was to evaluate the effect of age on lidocaine absorption and metabolism after application to the oropharynx and vocal cords in a manner similar to preparation for flexible fiberoptic bronchoscopy. Five healthy volunteers were studied in each of two age groups: from 25 to 37 and 60 to 68 years of age. Each volunteer had a total of lidocaine 300 mg administered as a gargle, gel, or directly to the vocal cords. Blood samples and expectorant were collected to determine concentrations of lidocaine and its metabolites, monoethylglycinxylidide (MEGX) and glycinxylidide (GX). No differences in peak plasma lidocaine concentrations, 2.09 +/- 1.28 mumol/L (1 microgram/mL = 4.27 mumol/L) in young subjects, and 2.35 +/- 0.85 mumol/L in young-elderly subjects, or lidocaine AUC were seen between the two age groups. Lidocaine recovered in expectorant ranged from 96 to 168 mg. This study suggests that, over the age range studied, increased age does not impair lidocaine absorption from the oropharynx or lidocaine metabolism when topical lidocaine is used during flexible fiberoptic bronchoscopy.

Absorption↗
PubMed1991

Pharmacokinetic simulation of the effect of multiple-dose activated charcoal in phenytoin poisoning--report of two pediatric cases.

Activated charcoal is commonly used to inhibit the absorption of phenytoin after acute overdose. There are also reports of multiple-dose activated charcoal (MDAC) increasing the clearance of phenytoin in adults. We describe our experience modeling phenytoin pharmacokinetics during therapy with MDAC in the treatment of two cases of acute phenytoin poisoning in children. After extensive attempts at modeling the serum phenytoin concentrations, simulations were performed to identify the possible consequences of MDAC administration. Phenytoin elimination was more rapid than was expected, based on previously reported phenytoin pharmacokinetic parameters. Moreover, the time to peak phenytoin concentration and time course of phenytoin intoxication appeared to be shorter than available reports of phenytoin intoxication treated with a single dose of activated charcoal. MDAC may prevent continued phenytoin absorption and increase phenytoin elimination rate via gastrointestinal dialysis. The effect of MDAC on the clearance of phenytoin can be described by a first-order elimination rate constant of approximately 0.02-0.04/h.

Charcoal↗
PubMed1991

Activated charcoal and acetylcysteine absorption: issues in interpreting pharmacokinetic data.

Studies determining the effects of activated charcoal on drug absorption frequently use area under the plasma drug concentration versus time curve or drug and metabolite recovery in the urine as endpoints. The considerations in using these endpoints is presented using studies that have evaluated the effects of activated charcoal on acetylcysteine absorption. Acetylcysteine's pharmacokinetics, quantitation of plasma concentrations, and the lack of an identifiable pharmacokinetic-pharmacodynamic relationship all contribute to the difficulties in determining whether activated charcoal inhibits the oral absorption of acetylcysteine, or alters acetylcysteine's efficacy in treating acetaminophen overdoses. The results of these studies should be interpreted cautiously, with consideration of internal and external study validity.

Absorption↗
PubMed1990

The emergency department treatment of dyspepsia with antacids and oral lidocaine.

The treatment of dyspepsia in the emergency department often consists of antacid in combination with viscous lidocaine, even though the specific etiology of the pain is frequently unknown. The efficacy of lidocaine as a component of symptomatic therapy was evaluated in a randomized, patient-blinded protocol. Patients presenting to the ED with dyspeptic symptoms were randomized to receive 30 mL of antacid (Mylanta II), or 30 mL of antacid plus 15 mL of 2% viscous lidocaine (GI cocktail). Patients recorded their pain score on an 11-cm linear analog scale prior to and 30 minutes after treatment. Seventy-six patients were enrolled; three were excluded from analysis due to incomplete data. Thirty-four patients were randomized to receive antacid and 39 to receive GI cocktail. Patients rated their baseline pain at 6.4 +/- 2.8 cm in the antacid group and 6.7 +/- 2.7 cm in the cocktail group (P greater than .50). Improvement in pain score with treatment was 0.9 +/- 2.9 cm in the antacid group compared with 4.0 +/- 3.4 cm in the GI cocktail group (P less than .0001). Assessment of pain relief using a five-point rating scale also indicated greater relief with GI cocktail therapy compared with antacid alone (P = .004). No adverse effects were noted with either treatment. We conclude that a single dose of antacid and viscous lidocaine provides a significantly greater degree of immediate pain relief than antacid alone in patients with dyspepsia.

Acute Disease↗
PubMed1990

Clinically significant radiograph misinterpretations at an emergency medicine residency program.

Radiographic misinterpretation rates have been suggested as a quality assurance tool for assessing emergency departments and individual physicians, but have not been defined for emergency medicine residency programs. A study was conducted to define misinterpretation rates for an emergency medicine residency program, compare misinterpretation rates among various radiographic studies, and determine differences with respect to level of training. A total of 12,395 radiographic studies interpreted by emergency physicians during a consecutive 12-month period were entered into a computerized data base as part of our quality assurance program. The radiologist's interpretation was defined as correct. Clinical significance of all discrepancies was determined prospectively by ED faculty. Four hundred seventy-five (3.4%) total errors and 350 (2.8%) clinically significant errors were found. There was a difference in clinically significant misinterpretation rates among the seven most frequently obtained radiograph studies (P less than .0005, chi 2), accounted for by the 9% misinterpretation rates for facial films. No difference (P = .421) was noted among full-time, part-time, third-year, second-year, and "other" physicians. This finding is likely due to faculty review of residents' readings. Evaluation of misinterpretation rates as a quality assurance tool is necessary to determine the role of radiographic quality assurance in emergency medicine resident training. Educational activities should be directed toward radiographic studies with higher-than-average reported misinterpretation rates.

Diagnostic Errors↗
PubMed1990

Clinical utility of a saliva alcohol dipstick estimate of serum ethanol concentrations in the emergency department.

Rapid determination of serum ethanol concentrations can be a useful adjunct in evaluating patients with decreased levels of consciousness. Previous reports suggest that saliva ethanol concentrations measured by a colorimetric saliva dipstick assay correlate well with serum ethanol concentrations and could be useful in the emergency department. We compared saliva dipstick assay results with concurrent serum ethanol measurements in 67 emergency department patients with altered mental status. Color changes of the stick are calibrated to reflect serum ethanol concentrations of negative (no color change), 4.3 mmol/L, 10.8 mmol/L, 21.7 mmol/L, and greater than or equal to 65.1 mmol/L. Emergency department staff were instructed to conduct the measurement according to the manufacturer's directions and round up equivocal results to the next highest concentration. Serum ethanol concentrations (mean +/- SD) grouped by dipstick results were: negative, 5.2 +/- 13.1 mmol/L; 4.3 mmol/L, 29.1 +/- 18.0 mmol/L; 10.8 mmol/L, 46.6 +/- 27.6 mmol/L; 21.7 mmol/L, 47.0 +/- 18.5 mmol/L; and 65.1 mmol/L, 62.4 +/- 24.2 mmol/L. There were 12 false-negative and 2 false-positive results. Correlation between dipstick results and serum ethanol concentrations was rho = 0.611 (p less than 0.0005). The lack of accuracy of the saliva dipstick measurements and the high number of false-negative results make it a poor choice for determining alcohol use in the emergency department patient.

Colorimetry↗