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Biomedical subjects

D H Yen

Publications and source records attributed to D H Yen.

7 recordsLinked to original sources
PubMed2001

Diagnosis of appendicitis in the ED: comparison of surgical and nonsurgical residents.

The purpose of this study was to evaluate the impact of a surgery-based (SB) versus nonsurgery-based (NSB) training background of residents on the diagnosis of acute appendicitis in the emergency department (ED). The medical records of 641 adult patients who had undergone an appendectomy during a 3-year period (July 1996 to June 1999) were reviewed. All the patients were divided into NSB-in charge (n = 367) and SB-in charge (n = 274) groups, and demographic and clinical data recorded. Both groups' patients showed no differences in either negative appendectomy or perforation rates. However, NSB group patients had longer in-hospital delays in comparison with SB group patients (12.0 +/- 0.7 versus 9.6 +/- 0.4 hours, P <.05). This longer stay time mainly occurred in the patients with negative exploration and uncomplicated appendicitis P <.05). In both groups, patients with complicated appendicitis had longer prehospital delay of presentation than those with uncomplicated appendicitis. (2.0 +/- 0.2 versus 1.2 +/- 0.1 days in NSB group; 2.5 +/- 0.5 versus 1.3 +/- 0.2 days in SB group, P <.01). The NSB residents tended to order more computed tomography (CT) scans than SB residents (12% versus 5.1%, P <.05). With the application of a CT scan, the negative appendectomy rate was reduced significantly from 23% to 12%. We concluded that under the supervision of board-certified emergency physicians, the NSB residents had capabilities similar to SB residents in making correct diagnoses of acute appendicitis. In addition, close observation of equivocal cases in the ED did not necessarily increase the perforation rate.

Adult↗
PubMed2001

Spectral changes in systemic arterial pressure signals during acute mevinphos intoxication in the rat.

We investigated the cardiovascular consequences of acute intoxication by the organophosphate poison, mevinphos (Mev), and delineated the underlying mechanism. Based on on-line power spectral analysis of systemic arterial pressure (SAP) signals in rats anesthetized and maintained by propofol, we identified two distinct phases after intravenous administration of Mev (160 or 320 microg/kg). Phase I was characterized by transient hypertension and mild tachycardia, concurrent with an increase in the very high-frequency (BVHF; 5-9 Hz), high-frequency (BHF; 0.8-2.4 Hz), low-frequency (BLF; 0.25-0.8 Hz),and very low-frequency (BVLF; 0-0.25 Hz) components of SAP signals. Phase II exhibited significant hypotension, a reversal of the BVHF and BVLF power to control levels, and further reduction in the power density of both BHF and BLF components to below baseline. Microinjection of Mev (2 microg) into the bilateral nucleus reticularis ventrolateralis (NRVL), the medullary origin of sympathetic neurogenic vasomotor tone, essentially duplicated those phasic cardiovascular changes. Similarly, sympathoexcitatory NRVL neurons exhibited respectively an elevation and a decline in their spontaneous activities during Phase I and Phase II Mev intoxication. We conclude that the progressive accumulation of acetylcholine over time induced by a direct inhibition of Mev on cholinesterase in the NRVL may be responsible for the phasic changes in cardiovascular events over the course of acute Mev intoxication. Whereas the initial amount of acetylcholine is excitatory to NRVL neurons, overstimulation by the amassed acetylcholine results instead of an inhibitory action.

Animals↗
PubMed2001

Characteristics of patients at a Taipei summer rock concert festival.

BACKGROUND: Rock concerts are popular mass gatherings in Taiwan. Millions of fans participate in rock concerts in Taiwan each year. However, there were no reports on the characteristics of the patients seen in rock concerts in Taiwan. METHODS: Medical care for a summer rock concert festival held in an outdoor stadium in Taipei was coordinated by emergency physicians of a medical center. About 50,000 attendees participated in the two-night concert. Three stations were set up to provide advanced medical care. A standardized form was used to collect information about patients. RESULTS: A total of 28 cases visited the medical stations, fourteen cases each day. They were aged from 13 to 40 years, with an average of 20.8 +/- 6.4. Twenty-one cases were female and seven were male. Twenty-two (79%) were spectators, five (18%) were on-duty staff, and one was a by-stander. Based on an estimation of totally 50,000 participants in the stadium for this two-night festival, the medical use rate was roughly 5.6 PPTT (patients per ten thousand attendees). The most common major problem was fainting which accounted for 13 cases (46%). Of these 13 cases, three cases (23%) lost consciousness and 12 cases (92%) were female. Sixteen cases (57%) were classified as requiring ALS (advanced life support) and 12 cases (43%) as requiring BLS (basic life support). Most cases improved and were discharged after onsite treatment. Only one case was transferred by ambulance due to persistent chest pain. However, she recovered several hours later. CONCLUSIONS: By this preliminary data, first reported in Taiwan, we found that the most common problem was fainting. More than half of the cases seen at the concert required advanced life support. A well-designed emergency medical service (EMS) system is mandatory to provide services for these events.

Adolescent↗
PubMed2000

Spectral analysis of systemic arterial pressure and heart rate signals of patients with acute respiratory failure induced by severe organophosphate poisoning.

OBJECTIVE: Spectral analysis of systemic arterial pressure (BP) and heart rate (HR) signals may be an alternative prognostic tool for predicting patient outcome in the intensive care unit (ICU). We evaluated the applicability of the same analysis in the emergency department for predicting mortality in patients with acute respiratory failure induced by severe organophosphate poisoning. DESIGN: Prospective collection of data from 14 emergency service patients. SETTING: Emergency service at a large, university-affiliated medical center. PATIENTS: Consecutive patients who, after attempting suicide by ingesting organophosphates, were admitted to the ICU of the emergency service with acute respiratory failure and remained for > or =2 days INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Demographic and survival data and day 1 Acute Physiology and Chronic Health Evaluation (APACHE) II and Glasgow Coma Scale scores were recorded. Continuous, on-line, real-time spectral analysis of BP and HR signals was carried out during the first 12 hrs after admission. We then computed the total sum of power density during this period of the low-frequency (0.04-0.15 Hz) and very low-frequency (0.004-0.04 Hz) components in the BP and HR spectra, along with the averaged values of mean BP and HR. Eight patients who recovered exhibited vigorous power in the low-frequency and very low-frequency components of their BP and HR signals. There was a significant reduction in the power density of those four spectral components in three patients who eventually died. Three patients discharged in a vegetative state manifested significantly reduced power in the low-frequency component in their BP spectra, with maintained power in the other three spectral components. APACHE II and Glasgow Coma Scale scores of the recovered patients were discernibly different from those of patients who eventually died or who became vegetative. None of the 14 patients showed appreciable differences in mean BP, mean HR, erythrocyte or plasma cholinesterase concentration, or atropine requirement during the first 24 hrs. CONCLUSION: The low-frequency and very low-frequency components of BP and HR signals may be a sensitive alternative index for early prediction of mortality in patients with acute respiratory failure induced by severe organophosphate poisoning.

Acute Disease↗
PubMed2000

Klebsiella pneumoniae renal abscess.

BACKGROUND: The clinical characteristics of renal abscess caused by Klebsiella pneumoniae have not been previously reported in case-series studies. The purpose of this study is to demonstrate the clinical characteristics of K pneumoniae renal abscess for early diagnosis and to identify the clinical risk factors associating with poor prognosis. METHODS: We retrospectively reviewed the medical records of 24 patients with K pneumoniae renal abscess, from April, 1982 through February, 1998. The clinical presentations, including the demographic characteristics, predisposing disorders, initial signs and symptoms, laboratory test results, diagnostic radiology studies, therapeutic modalities and risk factors associated with mortality were studied. RESULTS: The mean age was 58.7 years and the male to female ratio was 10:14. The most common predisposing factors were diabetes mellitus (58%), urolithiasis (25%) and immunosuppression (17%). Fever, chills and flank pain were the most common symptoms and signs, whereas pyuria, elevation of leukocyte count, glucose, blood urea nitrogen and creatinine were the common laboratory features. The distinct complications of K pneumoniae renal abscess were bacteremia in 13 (54%), emphysematous pyelonephritis in five (21%), and metastatic septic infection in three (12.5%). The cure rate was 52% (11/21) in patients treated with a combination of antibiotics and percutaneous drainage; however, six (35%) patients who survived required another surgical procedure for complete recovery. The overall mortality rate was 25%. The clinical factors of elderly age (>65 years) at presentation, lethargy, elevation of serum blood urea nitrogen and pulmonary complications were associated with poor prognoses. CONCLUSIONS: Focusing on the early diagnosis of K pneumoniae renal abscess and recognition of the prognostic factors for a poor prognosis, we highlight the specific clinical characteristics that include elderly age, lethargy, impairment of renal function, metastatic septic lesions and pulmonary complications. All patients with K pneumoniae renal abscesses should receive empiric antibiotics and percutaneous drainage or aspiration, and surgical intervention as necessary for patients with intractable disease.

Abscess↗
PubMed1999

Renal abscess: early diagnosis and treatment.

The purpose of this study was to identify initial clinical characteristics that can lead to early diagnosis of renal abscess in the emergency department and predict poor prognosis. A retrospective review of 88 renal abscess patients, from April 1979 through January 1996, was conducted. Patients were categorized into two groups. In group 1, renal abscess was diagnosed by an emergency physician, whereas in group 2 renal abscess was not diagnosed by an emergency physician. Clinical characteristics included demographic data, predisposing medical problems, duration of illness before diagnosis, time spent in hospital diagnosis, initial signs and symptoms, laboratory tests, and radiology studies that may have been useful in the early diagnostic regimes. Clinical factors were also analyzed for their value in predicting poor prognosis. The mean age of 88 patients with renal abscess was 59.8 years. The most common predisposing disorder was diabetes mellitus, followed by renal calculi and ureteral obstruction. The duration of diagnosis by emergency physicians was shorter for group 1 patients (1.2 +/- .4 v group 2, 2.8 +/- 2.9 days; P < .01) and the blood urea nitrogen level was higher in group 1 (55.7 +/- 42.2 mg/dL, v group 2, 33.5 +/- 33.5 mg/dL; P = .02). In the early diagnosis of renal abscess, emergency physicians should focus on patients who have predisposing disorders, ie, diabetes mellitus, renal stones, immunosuppression, longer duration of symptoms of urinary tract infection, and renal failure, who should promptly be investigated with ultrasound in the emergency department. The cure rate after treatment with routine antibiotics plus percutaneous drainage was 64%. This therapy is recommended for initial treatment. Poor prognosis is associated with elderly patients with lethargy and with elevation of the serum blood urea nitrogen level.

Abscess↗