Ruptured left subclavian artery aneurysm presenting as upper airway obstruction in von Recklinghausen's disease

Aneurysms arising from the subclavian artery are very rare vascular abnormalities in von Recklinghausen's disease, which often have a silent clinical presentation and are difficult to diagnose before rupture. We report a case of von Recklinghausen's disease with life-threatening upper airway obstruction caused by spontaneous rupture of the left subclavian artery aneurysm in a 46-year-old woman. The diagnosis was eventually confirmed by a reconstructed enhanced computed tomography of aorta. We emphasise the importance of it as a differential diagnosis because life-threatening upper airway obstruction may develop in such patient.

Comparison of clinical with pathological nodal staging from systematic mediastinal lymph node dissection in early resectable non-small cell lung cancer

INTRODUCTION

We compared the accuracy of clinical nodal (cN) status N0-1 with that of pathological nodal (pN) status obtained from systematic mediastinal lymph node dissection (SMLD) in primary non-small cell lung cancer.

METHODS

Data from 22 consecutive patients, who underwent lung cancer resection and SMLD of at least three mediastinal lymph node stations, from November 2001 to May 2003, were ana1ysed retrospectively. Only patients with cN0-1 status on computed tomography (CT) referred for surgery, were included in this study.

RESULTS

Mean age of patients was 66.6 +/- 8.1 years with a male to female ratio of 17:5. Mean number of lymph node stations dissected was 5.8 +/- 1.8. 41 percent had squamous cell carcinoma, 45.5 percent had adenocarcinoma, and 4.5 percent each had large cell carcinoma, bronchioalveolar carcinoma or a lymphoepithelial carcinoma. pN2 metastases were found in 27.3 percent of patients. The sensitivity of cN0-1 was only 12.5 percent, with a specificity of 92.9 percent and an area under the receiver operating characteristics curve of 0.53. The positive and negative predictive values of cN0-1 status were 50 percent and 65 percent, respectively, with an accuracy of 59 percent. 41 percent of patients were understaged with 27.3 percent in pathological stage III. Curative resections were achieved in 59 percent of patients.

CONCLUSION

The sensitivity of cN0-1 status based on CT alone is extremely poor when compared with pN status from SMLD. Based on cN0-1 status alone without SMLD, 27.3 percent of patients in pN2 would have been understaged. We recommend that all patients with cN0-1 status should undergo SMLD of at least three appropriate mediastinal node stations, for more accurate staging.

A risk score to predict silent myocardial ischemia in patients with coronary artery disease under aspirin therapy presenting with upper gastrointestinal hemorrhage

BACKGROUND

Silent myocardial ischemia (SMI) is a relatively common complication in patients with coronary artery disease (CAD) under aspirin therapy presenting with upper gastrointestinal hemorrhage (UGIH).

AIM

This study was conducted to develop and prospectively validate a risk prediction score to identify SMI in patients undergoing aspirin therapy for CAD presenting with UGIH in the emergency department (ED).

METHODS

This was a 2-phase noninterventional study. In the derivation phase, adults with CAD under aspirin therapy (100 mg once daily) presenting to the ED with UGIH were retrospectively recruited. By multiple logistic regression analysis, we derived a risk score from 224 patients that predicts the patients' risk of SMI. In the validation phase, we prospectively validated this score using receiver operating characteristic curves with data from 110 patients. We also developed a fast-track screening procedure from this score.

RESULTS

There were 56 patients (25.0%) and 29 patients (26.4%) with SMI in the derivation and validation sets, respectively. Independent multivariate predictors of SMI were age of older than 75 years, severity of CAD, systolic blood pressure of less than 110 mm Hg, diastolic blood pressure of less than 85 mm Hg, hematocrit of less than 30%, and blood urea nitrogen-creatinine ratio of more than 30. The area under receiver operating characteristic curve for the rule was 0.93 in the derivation set and 0.96 in the validation set. At the cutoff value of 5 points or higher, the sensitivity and specificity of the fast-track screening procedure for SMI were 96.6% and 86.4%, respectively. The positive and negative predictive values were 71.8% and 98.6%, respectively.

CONCLUSIONS

This simple risk prediction score is easily calculated and is based on rapidly available clinical and laboratory data in the ED. It can be used to stratify patients undergoing aspirin therapy for CAD presenting with UGIH by risk of SMI.

Unrecognized paroxysmal ventricular standstill masquerading as epilepsy: a Stokes-Adams attack

Recognition of cardiac syncope masquerading as epilepsy may be difficult in the Emergency Department. We report a middle-aged man with recent onset convulsions who posed a diagnostic puzzle before it was found that he had paroxysmal ventricular standstill with complete atrioventricular block: he made a complete recovery after temporary pacemaker insertion. The main lessons from this case were (1) a convulsive seizure of only seconds duration and with an abrupt return of consciousness suggests syncope not epilepsy, (2) repeated, convulsive syncopes without provocation suggest cardiac syncope, (3) a 12-lead ECG should be recorded as soon as possible after such a series of episodes and should not be discontinued until an event is captured, and (4) Emergency Department clinicians should be familiar with any automatic gain on their ECG machine, lest fast, atrial activity be mistaken for narrow complex tachycardia. In summary, a good clinical history is of prime importance in differentiating convulsive syncope from epilepsy, and a simple, non-invasive cardiovascular evaluation may help to diagnose the condition as cardiac syncope.

Cavernous sinus thrombophlebitis masquerading as ischaemic stroke: a catastrophic pitfall in any emergency department

Cavernous sinus thrombophlebitis is a clinically rare but fatal disease that progresses rapidly. Its initial presentation is always neglected by emergency physicians, until typical symptoms and signs are noted or thin-slice brain CT results obtained, by which time it is already too late. A case of cavernous sinus thrombophlebitis caused by sinusitis, which initially masqueraded as ischaemic stroke, is reported. Blindness of the left eye was the outcome. High suspicion, accurate diagnosis and aggressive antibiotic treatment are emphasised.

Development of a personal digital assistant-based wireless application in clinical practice

PURPOSE

Our study aims to develop a personal digital assistant (PDA)-based wireless application in medical information processing by using Bluetooth and IEEE 802.11b wireless standards and SyncML codes.

METHODS

In this study, an "integrated database access module" is used to provide a unified integrated access interface while consistency of wireless data transmission is achieved by using the standardized SyncML protocol. A prototype of the system has been developed, implemented, and tested for its mobility, usability, stability, and performance with questionnaire survey.

RESULTS

Response time for browsing/searching was usually less than 3s. The average time intervals needed for data transmissions were 68.6+/-8.5s for Bluetooth and 47.0+/-4.8s for 802.11b. The five-point Likert scale (from 1=least to 5=most) questionnaire survey of 30 medical professionals yielded a high degree of satisfaction with the system's mobility (4.18+/-0.89), usability (4.69+/-0.90), stability (3.81+/-0.94), and performance (3.97+/-0.88).

CONCLUSION

The results of our study suggested that PDA applications which exploit wireless communication are convenient and feasible in clinical practice.

Silent myocardial ischemia in coronary artery disease patients under aspirin therapy presenting with upper gastrointestinal hemorrhage

AIM

To identify the risk factors for myocardial ischemia in patients undergoing aspirin therapy for coronary artery disease (CAD) presenting with upper gastrointestinal hemorrhage and to ascertain the impacts on mortality and length of hospital stay.

METHODS

Adults with CAD under aspirin therapy (100 mg once daily) presenting to the emergency department with upper gastrointestinal hemorrhage were retrospectively recruited and divided into group A (ischemia) and group B (non-ischemia). Charts were reviewed for various demographic, laboratory and outcome data. Electrocardiograms were interpreted blindly by a senior cardiologist.

RESULTS

A total of 152 patients, 72.4% men and 27.6% women, were analyzed. Of these, 31 patients had ischemia and were placed in group A and 121 patients did not have ischemia and were in group B. Independent multivariate predictors of myocardial ischemia were history of triple vessel disease (odds ratio [OR], 9.24; 95% confidence interval [CI], 2.00-42.72), lower diastolic blood pressure (OR, 1.09; 95% CI, 1.02-1.16), lower hematocrit (OR, 1.41; 95% CI, 1.16-1.70), and higher blood urea nitrogen (OR, 0.94; 95% CI, 0.89-0.98). Patients with myocardial ischemia had significantly longer hospital length of stay (8.7 +/- 4.0 days vs 5.4 +/- 1.7 days; P < 0.001) and higher in-hospital mortality (16.1%vs 2.5%; P < 0.01) than did those without myocardial ischemia.

CONCLUSION

Myocardial ischemia is a relatively common complication in CAD patients under aspirin therapy presenting with upper gastrointestinal hemorrhage. A history of CAD with triple vessel disease, higher blood urea nitrogen, lower diastolic blood pressure and lower hematocrit may help identify patients who are at increased risk of myocardial ischemia, which tends to be associated with higher in-hospital mortality and increased length of hospital stay.

Low plasma vasopressin/norepinephrine ratio predicts septic shock

To evaluate if low plasma vasopressin and high norepinephrine concentrations predict grave prognosis of sepsis, a prospective sample of consecutive patients visiting the emergency department of a university teaching hospital who met the American College of Chest Physicians criteria of sepsis or severe sepsis was enrolled. Besides septic workup, we measured serum vasopressin and norepinephrine concentrations to correlate the impending outcome. One hundred eighty-two patients aged 27 to 99 years met the inclusive criteria and were classified as those with septic shock (n = 72), severe sepsis (n = 56), and those with sepsis only (n = 54) according to the outcome within 6 hours. Thirty healthy subjects were included as control. The plasma vasopressin level at baseline was significantly lower for those who finally developed septic shock (septic shock group, 3.6 +/- 2.5 pg/mL; 95% confidence interval [CI], 3.0-4.2 pg/mL; severe sepsis group, 21.8 +/- 4.1 pg/mL, 95% CI, 20.7-22.9 pg/mL; sepsis group, 10.6 +/- 6.5 pg/mL, 95% CI, 8.8-12.4 pg/mL, P < .001), whereas the norepinephrine level was highest for the same group (septic shock group, 3650 +/- 980 pg/mL, 95% CI, 3420-3880 pg/mL; severe sepsis group, 3600 +/- 1000 pg/mL, 95% CI, 3330-3870 pg/mL; sepsis group, 1720 +/- 320 pg/mL, 95% CI, 1630-1810 pg/mL). The vasopressin/norepinephrine ratio was significantly lower for the patients with final diagnosis of septic shock (P < .001). The mean interval between the time of samples drawn and the time of the most severe occurring sequelae was 2.4 +/- 0.8 hours. Receiver operating characteristic analysis revealed that the vasopressin/norepinephrine ratio 1 x 10(-3) had a sensitivity of 97% (95% CI, 90%-99%) and a specificity of 85% (95% CI, 78%-91%) for detecting impending septic shock. Low serum vasopressin/norepinephrine ratio can predict impending septic shock.

Esophageal rupture due to Sengstaken-Blakemore tube misplacement

The author presents three cases of esophageal rupture during the treatment of massive esophageal variceal bleeding with Sengstaken-Blakemore (SB) tube. In each case, simple auscultation was used to guide SB tube insertion, with chest radiograph obtained only after complete inflation of the gastric balloon. Two patients died of hemorrhagic shock and one died of mediastinitis. The author suggests that confirmation of SB tube placement by auscultation alone may not be adequate. Routine chest radiographs should be obtained before and after full inflation of the gastric balloon to confirm tube position and to detect tube dislocation.

Applying an artificial neural network to predict total body water in hemodialysis patients

BACKGROUND

Estimating total body water (TBW) is crucial in determining dry weight and dialytic dose for hemodialysis patients. Several anthropometric equations have been used to predict TBW, but a more accurate method is needed. We developed an artificial neural network (ANN) to predict TBW in hemodialysis patients.

METHODS

Demographic data, anthropometric measurements, and multifrequency bioelectrical impedance analysis (MF-BIA) were investigated in 54 patients. TBW measured by MF-BIA (TBW-BIA) was the reference. The predictive value of TBW based on ANN and five anthropometric equations (58% of actual body weight, Watson formula, Hume formula, Chertow formula, and Lee formula) was evaluated.

RESULTS

Predictive TBW values derived from anthropometric equations were significantly higher than TBW-BIA (31.341 +/- 6.033 liters). The only non-significant difference was between TBW-ANN (31.468 +/- 5.301 liters) and TBW-BIA (p = 0.639). ANN had the strongest Pearson's correlation coefficient (0.911) and smallest root mean square error (2.480); its peak centered most closely to zero with the shortest tails in an empirical cumulative distribution plot when compared with the other five equations.

CONCLUSION

ANN could surpass traditional anthropometric equations and serve as a feasible alternative method of TBW estimation for chronic hemodialysis patients.

A shortened dengue IgM capture ELISA using simultaneous incubation of antigen and peroxidase-labeled monoclonal antibody

A shortened IgM capture ELISA for the detection of dengue IgM antibodies using simultaneous incubation of antigen and peroxidase-labeled monoclonal antibody was described. The shortened two-step assay was compared with the four-step IgM capture ELISA on sera from dengue patients confirmed by the hemagglutination inhibition (HI) test. When paired acute and convalescent sera were tested, the shortened ELISA showed 100% agreement with HI results. It detected dengue IgM antibodies in the acute sera of 66% of patients with a primary dengue infection, 60% of patients with a secondary infection, and 98% of patients with a presumptive secondary infection. When the results of 151 dengue patients were combined, 75% of the acute sera were positive by the shortened IgM capture ELISA.

Preconsultation use of analgesics on adults presenting to the emergency department with acute appendicitis

OBJECTIVE

279 cases of appendicitis were reviewed and compared for the difference between those patients who received pain medication before consulting a surgeon and those who were not treated with analgesics.

METHODS

All patients aged 15 years and older who underwent appendicectomy for appendicitis between 1 July 2001 and 30 June 2002 were divided into group 1 (those who received preconsultaion use of analgesics) and group 2 (those who were not treated with analgesics). The following measures were compared: age, sex, symptom duration, initial vital signs, white blood cell counts, frequency of imaging studies, time to operative intervention, and operative findings. Continuous and categorical variables were analysed using t and chi(2) tests, respectively.

RESULTS

A total of 279 patients were included for analysis. Patient details (age, sex, symptom duration) of the two study groups were similar. There was no statistically significant difference between group 1 and group 2 with respect to vital signs (systolic blood pressure, pulse rate, respiratory rate, body temperature), white blood cell counts, and frequency of imaging studies (ultrasound, computed tomography). There was no significant difference in the rate of perforated appendicitis between the two study groups although a shorter median time to operative intervention has been found in the group who received analegesia.

CONCLUSION

The preconsultation use of analgesics in ED patients with a final diagnosis of appendicitis is not associated with a longer delay to operative intervention and is not associated with an increased rate of perforated appendicitis.

Establishing a clinical decision rule of severe acute respiratory syndrome at the emergency department

STUDY OBJECTIVE

In the absence of reliable rapid confirmatory tests during severe acute respiratory syndrome (SARS) endemics, we designed a 2-phase cohort study to establish a scoring system for SARS and to evaluate whether it could improve the sensitivity and specificity of the World Health Organization (WHO) criteria.

METHODS

According to the clinical characteristics and initial laboratory findings of 175 suspected cases defined by the WHO criteria (20 confirmed as cases of SARS) in 3 university teaching hospitals in Taipei between March 1 and April 20, 2003, the scoring system for SARS was designed by multivariate analysis and stepwise logistic regression as the simple arithmetic sum of point values assigned to 7 parameters. We thereafter applied the scoring system for SARS to the consecutive 232 patients (the validation group) who met the WHO criteria of suspected cases from April 21 to May 22, 2003. Final diagnosis of SARS was determined by the results of real-time polymerase chain reaction and paired serum.

RESULTS

The scoring system for SARS was defined as radiographic findings of multilobar or bilateral infiltrates (3 points), sputum monocyte predominance (3 points), lymphocytopenia (2 points), history of exposure (1 point), lactate dehydrogenase more than 450 U/L (1 point), C-reactive protein more than 5.0 mg/dL (1 point), and activated partial prothrombin time more than 40 seconds (1 point). Of the validation group, 60 patients (group A) were confirmed as having cases of SARS, and the other 172 (group B) patients tested negative for SARS. The total points of the scoring system for SARS at initial presentation were significantly higher in the SARS group (median 9; range 6 to 11) than in the non-SARS group (median 4; range 3 to 7; P<.001). At the cutoff value of 6 points, the sensitivity and specificity of the scoring system for SARS in diagnosing SARS were 100% and 93%, respectively. The positive and negative predictive values of the scoring system for SARS were 83% and 100%, respectively.

CONCLUSION

The scoring system for SARS can provide a rapid and reliable clinical decision to help emergency physicians detect cases of SARS more accurately in the endemic area.

Stratification of adverse outcomes by preoperative risk factors in coronary artery bypass graft patients: an artificial neural network prediction model

We constructed and internally validated an artificial neural network (ANN) model for prediction of in-hospital major adverse outcomes (defined as death, cardiac arrest, coma, renal failure, cerebrovascular accident, reinfarction, or prolonged mechanical ventilation) in patients who received "on-pump" coronary artery bypass grafting (CABG) surgery. We retrospectively analyzed a 5-year CABG surgery database with a final study population of 563 patients. Predictive variables were limited to information available before the procedure, and outcome variables were represented only by events that occurred postoperatively. The ANN's ability to discriminate outcomes was assessed using receiver-operating characteristic (ROC) analysis and the results were compared with a multivariate logistic regression (LR) model and the QMMI risk score (RS) model. A major adverse outcome occurred in 12.3% of all patients and 18 predictive variables were identified by the ANN model. Pairwise comparison showed that the ANN model significantly outperformed the RS model (AUC = 0.886 vs.0.752, p = 0.043). However, the other two pairs, ANN vs. LR models (AUC = 0.886 vs. 0.807, p = 0.076) and LR vs. RS models (AUC = 0.807 vs. 0.752, p = 0.453) performed similarly well. ANNs tend to outperform regression models and might be a useful screening tool to stratify CABG candidates preoperatively into high-risk and low-risk groups.

The development of an in-vitro perfusion system for studies on cultured cells

The design and use of a perfusion system, using a modified flow chamber for studies on cultured animal cells, is described. Rat thoracic aorta smooth muscle cells were isolated by an explant method and grown on Thermanox coverslips. These were introduced into the flow chamber. A flow rate of 25ml/min and a shear stress of 14.6 dynes/cm2 (12 dyne = 10 microN) (both within physiological limits) were maintained. Cells remained attached to the coverslips after 8h of perfusion with culture medium. The effect of exposing rat smooth muscle cells to the cardiovascular toxin, allylamine, is also described. The components of the system are routinely available, simple to clean, easy to assemble and sterilize. The incorporation of an in-line sensor that monitors pH, PO2, PCO2 and temperature ensures that the perfusion conditions remain within physiological limits. Automation means that minimal supervision is required. This system provides a potential mechanism in which cultured vascular cells may be perfused under controlled haemodynamic conditions, and their response to a cytotoxin may be evaluated.