Biomedical subjects

W B Liao

Publications and source records attributed to W B Liao.

13 recordsLinked to original sources

PubMed2006

Long-term efficiency and stability of wetlands for treating wastewater of a lead/zinc mine and the concurrent ecosystem development.

A constructed wetland system in Guangdong Province, South of China has been used for treating Pb/Zn mine discharge since 1985. The performance in the purification of the mine discharge and the concurrent ecosystem development within the system during the period of 1985-2000 has been studied. The untreated wastewater contained rather high concentrations of cadmium (Cd) (0.05 mg L(-1)), lead (Pb) (11.5 mg L(-1)), and zinc (Zn) (14.5 mg L(-1)), which greatly exceed the upper limits for industrial wastewater discharge in China. The constructed wetland system effectively removed Cd by 94.00%, Pb by 99.04%, Zn by 97.30%, and total suspended solids (TSS) by 98.95% from the mine discharge over a long period (over 16 years) leading to significant improvement in water quality; it was also found that there were no significantly annual or monthly variations in pH values, As, Cd, Hg, Pb, and Zn concentrations in water collected from the outlet of the wetland. Moreover, diversity and abundance of living organisms, including protozoan, higher plants, terrestrial animals, and birds, increased gradually. The 16-year monitoring results showed a reciprocal relationship, at a certain extent, between restoration of the wetland ecosystem, in other words, the maturity of the wetland, and the long-term efficiency and stability on purifying heavy metal-contaminated wastewater.

China↗

PubMed2000

Cardiovascular manifestations of pheochromocytoma.

Pheochromocytomas are rare tumors that originate in chromaffin tissue and produce their distant variant effects by secretion of catecholamines, tending to mislead the emergency physicians to a wrong diagnosis. Therefore, we analyze the clinical cardiovascular manifestations in patients with pheochromocytoma to improve the diagnostic ability of the emergency physicians. All patients presenting to the Chang Gung Memorial Hospital between January 1993 and December 1997 with a final diagnosis of pheochromocytoma had their charts reviewed. The data of 25 patients including age, sex, adrenergic stimulation presentations, electrocardiographic changes, location of the tumor, and complications were analyzed. Hypertension was the most important major manifestation and fluctuation of blood pressure drew our attention to the possibility of pheochromocytoma. Six patients had abnormal electrocardiographic ST-T segment changes. Five of them had chest pain which prompted them to undergo coronary angiography before surgery, because acute coronary syndrome (unstable angina and acute myocardial infarction) was suspected initially. However, all of them turned out to have normal coronary arteries. Right-sided pheochromocytoma was found in three of these five patients. We should maintain high index of suspicion for pheochromocytoma in patients presenting with chest pain, fluctuating blood pressure, and ischemic electrocardiogram (ECG) changes despite any typical isoenzyme changes. Pheochromocytoma should also be included in the differential diagnosis of acute coronary syndrome because acute catecholamine secretion may induce chest pain and abnormal ECG changes mimicking an ischemic episode. The right-sided pheochromocytoma may present more striking electrocardiographic abnormalities and clinical manifestations.

Adolescent↗

PubMed2000

Influential factors affecting prognosis of snakebite patients management: Kaohsiung Chang Gung Memorial Hospital experience.

BACKGROUND: The objective of this study was to determine the most influential factors affecting the prognosis of snakebite patients in Kaohsiung Chang Gung Memorial Hospital. METHODS: A thorough review of the medical records of poisonous snakebite from June 1986 to November 1999 was carried out in this retrospective study. RESULTS: Of the identified snakes in 39 bite victims, 70% of these cases were hemorrhagic type: Trimeresurus stejnegeri 20/27, T. mucrosquamatus 6/27, and Agkistrodon acutus 1/27; 28% were neurotoxic type: Naja naja atra 6/11 and Bungarus multicinctus 5/11; and 2% was mixed type: Vipera russelli formosensis 1/39. Three of four acute renal failure victims were bitten by T. mucrosquamatus. Two of the 5 victims bitten by B. multicinctus required endotracheal intubation to maintain their respiration. Five patients received skin grafting, 3 of whom were bitten by Naja naja atra. Most of our patients (55%) received only a single dose of antivenin, and 83% (29/35) of the antivenin was given within 6 hours after the bite; the antivenin infusion was finished in less than 2 hours in most cases (33/36). CONCLUSION: Bites from Trimeresurus stejnegeri are the most common poisonous snakebite recorded in our emergency department. T. mucrosquamatus is prominent in causing bleeding tendency and acute renal failure. Bungarus multicinctus is more prominent than Naja naja atra in causing acute respiratory failure. The dosage of antivenin used to treat patient bitten by cobra was less than that recommended by the poison control center, and the complication of skin necrosis requiring skin grafting was more severe than that of the other species.

Adolescent↗

PubMed1997

Cardiac tamponade in Taiwan.

We retrospectively reviewed all of the patients who were treated for cardiac tamponade at Linkou Chang Gung Memorial Hospital between January 1991 and December 1995. There were a total of 112 patients (57 males, 55 females) with a mean age of 51 +/- 14 years (53 +/- 15, 49 +/- 13, respectively). Dyspnea was the most common complaint (85%). The mean blood pressure was 129 +/- 24/78 +/- 17 mmHg, and only 8% had a systolic blood pressure of less than 90 mmHg. Sinus tachycardia was the most frequent electrocardiographic finding (72%, 62/86). Diffuse low voltage was noted in 35% (30/86) of the patients and electrical alternans was seen in 17% (15/86). The mean volume of pericardial effusion was 610 +/- 263 ml. Sixty-five percent of the pericardial effusions were bloody, 31% were serosanguineous, 2% were purulent and 2% were chylous. Overall, 54.5% of the patients had malignant diseases. Of the 61 patients who died, 79% had malignancies. Thirty-five (57%) of these 48 patients had lung cancer. The mean survival time from emergent pericardiocentesis was 3.4 months. In conclusion, non-traumatic cardiac tamponade had a poor prognosis because most patients had malignant etiologies. There is still no definitive treatment for recurrent malignant pericardial effusion-induced cardiac tamponade. Percutaneous pericardiocentesis as clinically required may be the most appropriate treatment, since it is questionable whether such subjects should be subjected to the unnecessary pain and suffering associated with an operative procedure, considering their short mean survival time.

Adolescent↗

PubMed1997

Thrombectomy for left ventricular protruding thrombi in a patient with dilated cardiomyopathy.

Left ventricular thrombus is one source of cardiogenic embolism. The protruding, mobile type is the highest risk subgroup but is rarely encountered. Thrombectomy is one choice of therapy, and variously recommended based primarily on the experience with myocardial infarction. We report a rare case of successful left ventricular thrombectomy for two protruding, mobile thrombi in a patient with idiopathic dilated cardiomyopathy in order to prevent repeat embolization.

Adult↗

PubMed1997

Cardiac perforation and tamponade induced by external cardiac massage: a case report.

A 76-year-old woman suffered from sudden loss of consciousness while sitting in a chair. She was sent to a local hospital and found to be in shock. After a brief period of external cardiac massage, she was transferred to our hospital. In our emergency department she was lethargic with cool, clammy extremities. Her blood pressure dropped from 113/53 mmHg on arrival to 72/42 mmHg 2 hours later. Echocardiography showed massive pericardial effusion, fair left ventricular contractility and no abnormal segmental motion. The echocardiographic appearance suggested fibrin-like substance in the pericardial space, which was felt to indicate the presence of blood. Enhanced chest computerized tomography showed extravasation of contrast medium from the right ventricular outflow tract. At surgery, a small perforation was found at the infundibular area of the right ventricle, and a total of 500 mL of blood had accumulated in the pericardial space. She was discharged 7 days postoperatively, having made an uneventful recovery. External cardiac massage may cause cardiac disruption, and this should be considered in patients who have secondary hemodynamic instability following successful cardiopulmonary resuscitation.

Aged↗

PubMed1996

Defecation induced deep venous thrombosis. A case report.

While the risk of deep venous thrombosis (DVT) during prolonged fights is well recognized, we present the case of a 54-year-old male who suffered a deep venous thrombosis following defecation. Defecation, through a combination of the Valsalva maneuver and squatting, led to a DVT due to venous stasis, most marked in the left leg. Color-duplex scanning not only proved a convenient diagnostic tool but also allowed for monitoring and documentation of popliteal and saphenous vein recanalization. Being non-invasive and complication-free, color-duplex scanning should be considered for any patient in whom DVT is a possibility.

Angiography↗

PubMed1996

Deep venous thrombosis in Taiwan.

We retrospectively reviewed all patients with a final diagnosis of deep venous thrombosis (DVT) treated at Linkou Chang Gung Memorial Hospital between 1989 and 1995. There were a total of 245 patients with a mean age of 58 years (males 56 and females 59), ranging from 11 to 89 years. The ratio of left to right leg involvement was 2.4 to 1 (166 to 71), however, the right leg was more likely to lead to an acute pulmonary embolism, with a ratio of 3.0 to 1 (9/ 71 to 7/166 patients). Among these patients, 16.3% (40) had cancer. The most frequently involved system was the GI system (16). Adenocarcinoma proved the most common type of malignancy 62.5% (25/40). From this analysis, we found the left leg had a higher likelihood of thrombosis but a DVT of the right leg was more frequently associated with an acute pulmonary embolism. As with previous reports there was a strong relationship between cancer and DVT and the development of a deep venous thrombosis requiring a search for an underlying malignancy in those patients with an unexplained DVT.

Acute Disease↗

PubMed1996

Anticholinergic overdose induced torsade de pointes successfully treated with verapamil.

An 18-year-old schizophrenic female was recently treated after overdosing on trihexyphenidyl, thioridazine and an unknown antidepressant. On presentation to a local hospital, she was cyanotic with dilatated pupils and in acute respiratory failure. She was intubated prior to transfer. While in our Emergency Department, she exhibited occasional premature ventricular contractions which later became intermittent torsade de pointes. As this was an anticholinergic overdose we infused sodium bicarbonate in an attempt to increase protein binding, hoping to decrease the concentration of toxic metabolites. We also tried to suppress the dysrhythmia by infusing magnesium. The potassium level was borderline low so a supplemental infusion was initiated. Defibrillation was attempted. To try to shorten the action potential duration by activating the K+ channel, an isuprel infusion was also attempted. All methods failed. The patient fluctuated between an irregular sinus rhythm with prolonged QT interval and pulseless torsade de pointes for almost 24 hours. At all times, she responded appropriately to pain. Finally we attempted blockade of the calcium channel using verapamil with dramatic results. Each single bolus (0.1 mg/kg) successfully converted the patient back to sinus rhythm for some 15-20 minutes before the torsade recurred. After the initiation of a continuous verapamil infusion (0.005 mg/kg/hr), the patient remained in stable sinus rhythm. Verapamil proved highly effective in this patient with an anticholinergic overdose induced dysrhythmia.

Adolescent↗

PubMed1996

Metastatic colonic carcinoma with intracavitary right ventricular outflow tract obstruction and cardiac tamponade: a case report.

Intracavitary metastasis causing right ventricular outflow tract (RVOT) obstruction is very rare. Combination of cardiac tamponade with RVOT obstruction due to intracavitary metastasis has never been reported in the literature. Herein, we report a case of colonic carcinoma with sudden onset of severe dyspnea. Echocardiography detected cardiac tamponade as well as a huge intracavitary mass obstructing the RVOT. Pericardiocentesis and surgical resection of the right ventricular mass were performed but the patient died during operation. Thus, the combination of intracavitary RVOT obstruction and cardiac tamponade in a patient with carcinoma suggests extensive myocardial and pericardial involvement with a poor prognosis.

Cardiac Tamponade↗

PubMed1995

Aortic dissection in Taiwan.

We retrospectively reviewed all patients with a final diagnosis of spontaneous thoracic aortic dissection treated at Linkou Chang Gung Memorial Hospital between January 1989 and December 1994. There were a total of 109 patients with a mean age of 55 +/- 11 years ranging from 19 to 88 years. The male-to-female ratio was 2 to 1 (73 to 36). There was a predilection to present during the colder months, with 69% seen between September 1 and February 28 and only 31% during the warmer half of the year. In most patients, hypertension (85%) was the major predisposing factor with another 7% having Marfan syndrome. The remaining 8% had no obvious underlying disease except for one patient who had an atrial septum defect. Presenting chief complaints in order of frequency included: anterior chest pain 58.7% (64/109), back pain 19.2% (21/109), abdominal pain 10.1% (11/109), consciousness change 3.7% (4/109), neck pain 2.7% (3/109), paraparesis 2.7% (3/109), dyspnea 1.8% (2/109), and hemoptysis 0.9% (1/109). The diagnostic breakdown revealed 46% to be type A (50/109) and 54% type B (59/109). A total of 26 (24%) patients died in hospital (16% were type A and 8% were type B). (Type A included all proximal dissections and those distal dissections that extend retrograde to involve the arch and ascending aorta; Type B refers to the other distal dissections without proximal extension; proposed by Daily et al.) Thoracic aortic dissection remains an important concern in patients with a history of hypertension. Patients seem particularly susceptible during cold weather months. The average age of our patients was only 55 years and 24% of them died during hospitalization. Earlier identification and more aggressive antihypertensive treatment is required.

Adult↗

PubMed1995

Widespread embolism in a patient with infective endocarditis--a case report.

A 28-year-old man with a history of rheumatic heart disease, alcoholism and amphetamine abuse presented with severe left upper quadrant abdominal pain and persistent fever. He stayed at home for the previous two months due to intermittent dull lower abdominal pain, chills, fever and tarry stools without seeking medical help. A diagnosis of infective endocarditis with splenic infarcts and a renal infarct was made based on the echocardiographic and abdominal computer tomography scan findings. His clinical course was complicated by an acute inferior wall myocardial infarction and cerebral hemorrhage. Despite aggressive medical treatment, his condition deteriorated. One month later, his condition became more critical with pneumonia and intractable shock, and his family requested his discharge. He died soon after leaving the hospital.

Adult↗

PubMed1995

Multiplane transesophageal echocardiography in traumatic aortic dissection: a case report.

We report a case of a 23 year old male who suffered a traffic accident and had a suspicious widening of the mediastinum on chest x-ray. Computed tomography (CT) failed to demonstrate an aortic dissection. Due to the mechanism of injury and chest X-ray findings, we decided to perform a multiplane transesophageal echocardiogram (MTE). This revealed an aortic dissection of less than one centimeter in length and good heart function. Due to CT evidence of hemoperitoneum, the patient received an emergent laparatomy. A liver laceration and jejunal perforation were found and repaired. An intraabdominal abscess developed, which led to sepsis, multiple organ failure and ultimately death. MTE was used to monitor the status of the dissection and adequacy of heart function during his intensive care unit stay. The dissection extended to 4 cm in length by the second week and then remained stable. There was no thrombus formation within the false lumen by the third month. While the patient unfortunately died from complications related to his abdominal injuries, MTE not only diagnosed the traumatic aortic dissection when CT failed, but allowed easy monitoring of both the rate of extension and the flow patterns within the false lumen. This made prognostication and treatment planning much easier.

Adult↗