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Ping-Wing Lui

Publications and source records attributed to Ping-Wing Lui.

At least 19 recordsLinked to original sources
PubMed2006

Propofol improves endothelial dysfunction and attenuates vascular superoxide production in septic rats.

OBJECTIVE: To determine the effects of propofol on vascular functions, plasma and endothelium-derived nitric oxide (EDNO), vascular NO, and cyclic guanosine monophosphate (cGMP), as well as vascular production of superoxide anion (O2*-), in septic animals. DESIGN: Prospective, multiexperimental, randomized, controlled studies. SETTING: University research laboratory. SUBJECTS: Male adult Sprague-Dawley rats weighing 350-400 g. INTERVENTIONS: Cecal ligation and puncture (CLP), with and without propofol (25 mg/kg/hr) infusion, after sham or CLP (24 hrs postsurgery). MEASUREMENTS AND MAIN RESULTS: Plasma NOx, basal aortic NOx, and cGMP concentrations all increased, whereas acetylcholine-induced endothelium-dependent relaxation (EDR), contractile response, and EDNO all decreased in CLP vs. sham rats (p < .001). Acetylcholine stimulated aortic NOx and cGMP significantly in sham and CLP-propofol (p < .01) but not CLP rats. Thus, propofol ameliorated the CLP-induced increases in plasma NOx, basal aortic NOx, and cGMP. It restored the CLP-induced impairment of EDR, EDNO, and acetylcholine-stimulated aortic NOx and cGMP levels. More O2*- production (measured by lucigenin-enhanced chemiluminescence) was noted in carotid arteries from CLP vs. sham rats (p < .001). Nicotinamide adenine dinucleotide (NADH; 1 mM) stimulated O2*- production in all rings, with significantly more increase in CLP vs. sham (p < .001). Propofol attenuated the excessive increase in O2*- production of CLP rings. CONCLUSIONS: Propofol treatment attenuated the overproduction of NO and O2*-, thus restoring the acetylcholine-responsive NO-cGMP pathway in CLP-induced sepsis. It also significantly improved the CLP-impaired EDR and EDNO in a parallel manner. These beneficial effects of propofol could be accounted for by improvement of the disturbed NO/O2*- balance in sepsis.

Animals↗
PubMed2006

Evaluation of the longitudinal contraction of the ventricle septum in patients undergoing off-pump coronary artery bypass graft surgery by strain rate imaging.

BACKGROUND: Strain rate (SR) imaging is an emerging technique for assessing myocardial systolic and diastolic functions. This technique can provide assessment in real time and color mapping; it also can detect ischemia at its earlier stages in comparison with visual estimation of wall motion with other techniques. METHODS: This study group consisted of 9 patients undergoing elective coronary artery bypass graft (CABG) surgery. After general anesthesia with sevoflurane (end-tidal 1.8%) in air/oxygen mixture, a complete transesophageal echocardiography (TEE) study was performed with an ultrasound machine. Myocardial wall strain rate imaging was then preformed off-line using a customized computer software (Echopac, Windows 2000 version 2.1, General Electric) running on a Compaq P4 computer. The experimental protocol was divided into 6 parts: (1) T1: 30 minutes after general anesthesia completed, (2) T2: after opening the sternum and pericardium, (3) T3: left anterior descending coronary artery(LAD) snared for the preparation of ischemic pre-conditioning (SLAD), (4) T4: after anastomosing left internal mammary artery (LIMA) on LAD, (5) T5: before closing the sternum and pericardium and (6) T6: after closing the sternum and pericardium. RESULTS: From strain rate imaging, peak systolic SRs were reduced or inverted over LAD perfused area during the SLAD period. In apical segments, peak systolic SR changed from -0.45 +/- 0.48 to 0.42 +/- 0.63 (P < 0.05), whereas peak diastolic SR changed from 0.34 +/- 0.61 to -0.80 +/- 1.08 (P < 0.05). In the middle septum, peak systolic SR changed from -0.67 +/- 0.51 to -0.43 +/- 0.50 (P < 0.05), while peak diastolic SR changed from 0.47 +/- 0.44 to -0.64 +/- 0.84 (P < 0.05). After LIMA grafting, peak systolic SR changed from 0.42 +/- 0.63 to -0.61 +/- 0.40 (P < 0.05), as against peak diastolic SR which changed from -0.80 +/- 1.08 to 0.21 +/- 0.44 (P < 0.05) in the apical septum. Peak systolic SR changed from -0.43 +/- 0.50 to -0.75 +/- 0.46 (P < 0.05), whereas peak diastolic SR changed from -0.64 +/- 0.84 to 0.64 +/- 0.88 (P < 0.05) in the middle septum. CONCLUSIONS: Postsystolic shortening is a marker for both ischemia and successful myocardial reperfusion. By strain rate imaging, we could detect ischemia with a more sensitive and specific method. For anesthesiologists and surgeons, it can be an intraoperative tool for assessing ventricular function after reperfusion.

Aged↗
PubMed2006

Difficult oral endotracheal intubation in an acromegalic patient receiving transsphenoidal surgery--a case report.

Patients suffering from acromegaly are associated with increased risks of difficult airway management. We report a case of acromegaly scheduled for transsphenoidal resection of pituitary adenoma under general anesthesia in whom all possible means failed us in the insertion of the endotracheal tube (ET) through the mouth, a procedure essential for transsphenoidal surgery. The operation was called off and for securing his compromised airway a nasal ET was placed under fiberoptic bronchoscopy. Five days later, awake oral fiberoptic intubation was successful under topical anesthesia. We suggest that oral endotracheal intubation performed awake under topical anesthesia with the aid of a fiberoptic bronchoscope is a choice approach in acromegalic patients with predicated difficult airway who are to receive surgery.

Acromegaly↗
PubMed2006

Myocardial infarction masked by high level spinal anesthesia in a patient undergoing herniorrhaphy.

Myocardial infarction (MI) is one of the leading causes of perioperative morbidity. Although evidence to prove significant reduction of perioperative MI with regional anesthesia is lacking, anesthesiologists still prefer this technique over general anesthesia for surgery involving the lower abdomen or lower extremities, especially in patients with cardiac risks. However, high level of sensory block during spinal anesthesia may obscure the referred pain from MI, which could contribute to the delay of diagnosis and treatment of an acute perioperative attack. We report a case of MI which occurred either intraoperatively or postoperatively, with symptoms that were masked by high level of sensory block to T4 by spinal anesthesia. This perioperative MI was only diagnosed when the patient recovered from anesthesia in the post-anesthesia care unit (PACU).

Aged↗
PubMed2005

Ultrasound-guided axillary brachial plexus block in patients with chronic renal failure: report of sixteen cases.

In this report, 16 patients with end-stage renal disease undergoing forearm arteriovenous shunt surgery were subjected to an ultrasound-guided axillary approach for brachial plexus nerve block. Two doses of 15 ml lidocaine 1.5% were injected using a double-shot technique The spread of the solution within the plexus sheath could be visualized using a high-resolution 12-MHz imaging probe. Most patients (94%) experienced an excellent analgesia in the regions innervated by median, ulnar and radial nerves with a lower percentage of complete analgesia (63%) in the areas innervated by musculocutaneous nerve. Three patients, who complained of pain during the surgery required further supplements of narcotics. There were no complications such as, nerve injury, puncture of the axillary vessels or other systemic reactions. This technique provides adequate analgesia - without complications and without difficulty - for extremity surgery in patients with end-stage renal diseases.

Aged↗
PubMed2005

Paraplegia by acute cervical disc protrusion after lumbar spine surgery.

Non-traumatic paraplegia caused by herniation of the cervical intervertebral disc is an uncommon postoperative complication. A patient with claudication and radiculopathy was scheduled for lumbar laminectomy due to spinal stenosis. Postoperatively, numbness below T6 was found in his both legs of the patient. MRI showed a protruded intervertebral disc between C6 and C7. Despite urgent disectomy, the patient's lower extremities remained paralyzed without significant improvement for 3 months. Loss of muscle support during general anesthesia, excessive neck extension during endotracheal intubation and positioning, as well as bucking and agitation are believed as triggering factors for the protrusion of the cervical disc. We suggest that a complete history taking and physical examination be accomplished in patients scheduled for lumbar spine surgery in order to exclude coexisting cervical spine disorders. In addition, skillful endotracheal intubation and careful neck positioning are mandatory for patients receiving surgery in the prone position.

Acute Disease↗
PubMed2005

Airway obstruction by a metastatic mediastinal tumor during anesthesia.

A case of low back pain syndrome was diagnosed due to spinal metastasis with unknown primary origin. During anesthesia for surgical stabilization, unexpected airway obstruction occurred after endotracheal intubation. Fiber-optic bronchoscopic examination showed narrowing of the trachea and main bronchi caused by extrinsic compression. After administration of neostigmine to reverse neuromuscular blockade, the patient resumed spontaneous breath. Airway obstruction was relieved thereafter. The extrinsic lesion was diagnosed as mediastinal lung cancer. The mechanism and management of this airway compromise caused by mediastinal tumor is discussed.

Adult↗
PubMed2005

Efficacy of ultrasound-guided axillary brachial plexus block: a comparative study with nerve stimulator-guided method.

BACKGROUND: The aim of this study was to compare the efficacy of axillary brachial plexus block using an ultrasound-guided method with the nerve stimulator-guided method. We also compared the efficacy of ultrasound-guided single-injection with those of double-injection for the quality of the block. METHODS: Ninety patients scheduled for surgery of the forearm or hand were randomly allocated into three groups (n = 30 per group), i.e., nerve stimulator-guided and double-injection (ND) group, ultrasound-guided and double-injection (UD) group, and ultrasound-guided and single-injection (US) group. Each patient received 0.5 ml kg(-1) of 1.5% lidocaine with 5 mg kg(-1) epinephrine. Patients in the ND group received half the volume of lidocaine injected near the median and radial nerves after identification using a nerve stimulator. Patients in the UD group received half the volume of lidocaine injected around the lateral and medial aspects of the axillary artery, while those in the US group were given the entire volume near the lateral aspect of the axillary artery. The extent of the sensory blockade of the seven nerves and motor blockades of the four nerves were assessed 40 min after the performance of axillary brachial plexus block. RESULTS: Seventy percent of the patients in the ND and US groups as well as 73% of the patients in the UD group obtained satisfactory sensory and motor blockades. The success rate of performing the block was 90% in patients in the ND and UD groups and 70% in the US group. The incidence of adverse events was significantly higher in the ND group (20%) compared with that in the US group and the UD group (0%; p = 0.03). CONCLUSIONS: Ultrasound-guided axillary brachial plexus block, using either single- or double-injection technique, provided excellent sensory and motor blockades with fewer adverse events.

Adult↗
PubMed2005

The effects of continuous axillary brachial plexus block with ropivacaine infusion on skin temperature and survival of crushed fingers after microsurgical replantation.

BACKGROUND: Continuous axillary brachial plexus block with local anesthetic has been shown to improve tissue perfusion after replantation surgery of the extremity. The present study aimed to investigate whether continuous axillary brachial plexus block with ropivacaine infusion can improve the survival of the reconstructive fingers secondary to an increase in its skin temperature in patients receiving replantation surgery of the crushed fingers. METHODS: Under general anesthesia, 18 patients received replantation or toe-to-hand transplantation of their crushed digits. They were randomly divided into two groups. Under ultrasound guidance, continuous axillary brachial plexus analgesia was effected by a loading dose of 10 ml 0.75% ropivacaine, followed by an infusion of 4-5 ml per hour for up to three days (Group A). Patients who did not receive continuous analgesia postoperatively served as a control (Group B). An infrared thermometer was used to hourly assess the skin temperature of the surgical and non-surgical sites in both groups for 24 h after the surgery. In addition, the survival (the rate of re-operation or amputation) of the reconstructive digits was also evaluated in both groups. RESULTS: The skin temperature of the digits (T1) on both groups did not show any significant difference at any point of time after the surgery albeit there was a trend of increased skin temperature on the reconstructive digits in patients receiving continuous axillary brachial plexus block (Group A) as compared to those without receiving the block (Group B). Also, the difference in skin temperature (dT) differed slightly at 0, 9 and 21 hours postoperatively in Group A in comparison with Group B (0.75 +/- 0.65 vs. -2.33 +/- 1.24, 0.53 +/- 0.34 vs. -3.02 +/- 1.27, -0.125 +/- 0.55 vs. -2.33 +/- 0.91, p < 0.05). However, no patients in both groups received a second operation or amputation of the graft. CONCLUSIONS: The result of this study demonstrated that axillary brachial plexus block with continuous infusion of 0.75% ropivacaine can increase the skin temperature, an index of tissue perfusion, of the reconstructive digits for 24 h after microvascular surgery of the crushed fingers. However, graft survival was good in both groups.

Adult↗
PubMed2004

Preemptive effects of intrathecal cyclooxygenase inhibitor or nitric oxide synthase inhibitor on thermal hypersensitivity following peripheral nerve injury.

The present study provides an important implication for the management of chronic neuropathic pain, focusing on prostaglandin (PG) and nitric oxide (NO) in the spinal cord. To determine if spinally administered cyclooxygenase (COX) inhibitor or nitric oxide synthase (NOS) inhibitor had preemptive analgesia on thermal hypersensitivity induced by chronic constrictive nerve injury, Sprague-Dawley rats were chronically implanted with an intrathecal (i.t.) catheter. The left sciatic nerve was loosely ligated with 2-mm polyethylene tubing to produce painful mononeuropathy. Animals received tenoxicam (7.5, 15 or 30 micromol/10 microl, i.t.), NS-398 (15 or 30 micromol), or L-NAME (30, 150 or 300 micromol) immediately before the nerve injury, followed by daily injection extending into the four postoperative days. The hindpaw was immersed into a hot (42 degrees C, 44 degrees C and 46 degrees C) or cold (10 degrees C) water bath. The paw immersion test revealed significant thermal hyperalgesia and allodynia 5 day after nerve injury in vehicle control animals. Tenoxicam (7.5, 15 or 30 micromol) or L-NAME (30, 150 or 300 micromol) dose-dependently attenuated hyperalgesia and allodynia. Equimolar dose of NS-398 (15 or 30 micromol) also diminished these nociceptive behaviors. Higher dose of either drug primarily produced longer duration of inhibition. The inhibitory effect of tenoxicam (30 micromol) on hyperalgesia was more effective than that of an equimolar dose of NS-398 or L-NAME. These results demonstrated that intrathecally administered COX inhibitor or NOS inhibitor provides preemptive analgesia on thermal hypersensitivity following chronic constrictive nerve injury in rats.

Animals↗
PubMed2004

Fatal ischemia stroke in a patient with an asymptomatic carotid artery occlusion after lumbar spine surgery--a case report.

Recognizing carotid artery stenosis (CAS) in an asymptomatic patient preoperatively is difficult. We report a 63-year-old female who had diabetes mellitus and hypertension suffered from a fatal ischemic stroke secondary to a total occlusion of the left carotid artery after a lumbar spine surgery in the prone position. Intraoperative induced hypotension and neck rotation in this patient should be considered as contributory factors. According to previous studies extensively screening out CAS is not recommended. Using electroencephalography (EEG) or somatosensory evoked potential (SSEP) to monitor brain function and carefully positioning of the neck are recommended in these patients who are at risk of stroke while receiving induced hypotension during lumbar spine surgery in the prone position.

Arterial Occlusive Diseases↗
PubMed2004

High satisfaction with problem-based learning for anesthesia.

BACKGROUND: The aim of this study was to compare students' satisfaction between problem-based learning (PBL) and lecture-based traditional teaching of anesthesia. METHODS: One hundred and thirty-seven fifth-year medical students were enrolled in a course which used a hybrid curriculum for teaching about anesthesia. The hybrid curriculum included 9 essential lectures and 3 related PBL case discussions. A Linkert 5-point scale was used for to assess students' satisfaction levels between PBL and lecture-based traditional teaching. Data were collected through a year-end questionnaire over 2 academic years from 2002 to 2003. Scores regarding the satisfaction levels between these 2 teaching methods were analyzed using a 2-sided paired t-test. RESULTS: Most students preferred PBL over the lecture-based traditional teaching in the following 6 aspects: learning about anesthesia, understanding other medical knowledge, being interested in and motivated to learn, training for future work, training of personal abilities, and being confident and satisfied with the teaching method (p < 0.05). However, traditional teaching was superior to PBL in enhancing the speed of learning with greater understanding of a basic knowledge of anesthesia, as well as in providing more solid content with understanding of a greater number of anesthetic techniques (p < 0.05). Satisfaction levels with this curriculum did not generally differ between students enrolled in different classes in 2002 and 2003. CONCLUSIONS: Although the assessment tools and content of PBL need to be modified, implementation of PBL for teaching anesthesia showed satisfactory results.

Anesthesiology↗
PubMed2004

Efficacy and adverse effects of patient-controlled epidural or intravenous analgesia after major surgery.

BACKGROUND: The purpose of this retrospective study was to determine whether epidural fentanyl-bupivacaine patient-controlled analgesia (PCA) was more efficacious and had fewer adverse effects than epidural or intravenous morphine PCA. METHODS: We retrospectively retrieved data from 859 patients (mean age 64+/-7 years) who received continuous epidural medication, either morphine or fentanyl-bupivacaine PCA, or intravenous morphine PCA for postoperative pain control after major elective surgery from 1999 to 2000. Pain was assessed postoperatively using a verbal analogue pain scale (VAS, 0-10) during rest, mobilization, and coughing. Adverse effects including nausea, vomiting, pruritus, urinary retention, sedation, motor block, and respiratory depression (< 8 breaths per minute) were recorded. On the third postoperative day, the overall quality of pain control was evaluated using a pain relief scale (PRS, 1-4). RESULTS: There were 201 patients who had epidural morphine PCA, 427 patients who had fentanyl-bupivacaine PCA, and 231 patients who had intravenous morphine PCA. Most patients (> 86%) who received epidural or intravenous PCA, either morphine or fentanyl combined with bupivacaine, experienced good pain relief (VAS, 0-3) during rest, mobilization, and coughing. Nonetheless, patients who received epidural morphine or fentanyl-bupivacaine had greater satisfaction with overall pain relief (PRS = 4) than did those who received intravenous morphine (p<0.05). Nausea and vomiting were most common in the epidural morphine group (p<0.05). Pruritus occurred least often in patients who received epidural fentanyl-bupivacaine analgesia (p < 0.05). There were no differences in other adverse events such as urinary retention, sedation, and motor block among the three groups. No respiratory depression was found in any patient. CONCLUSIONS: Patients receiving epidural fentanyl-bupivacaine PCA experienced better overall pain relief, while morphine PCA, either epidurally or intravenously, caused more side effects. It is considered safe to use continuous epidural PCA with fentanyl-bupivacaine in patients receiving major elective surgery.

Aged↗
PubMed2003

Pretreatment with small-dose ketamine reduces withdrawal movements associated with injection of rocuronium in pediatric patients.

UNLABELLED: We evaluated the pretreatment of small-dose of ketamine or normal saline in the reduction of withdrawal movements induced by rocuronium injection. One-hundred pediatric patients (aged 1-6 yr) were randomly assigned into 2 groups. A 22-gauge IV cannula was inserted into the dorsum of the hand, and ketamine 0.2 mg/kg or normal saline was given, followed by a 5 mg/kg thiopental injection 10 s later. IV rocuronium (0.8 mg/kg) was injected over 5 s. The patient's response to rocuronium injection was graded by using a four-point scale in a double-blinded manner. We observed that the incidence of withdrawal movements was 83% in the saline group and 27% in patients pretreated with ketamine (P < 0.05). Some patients in both groups developed skin erythema at the site of injection. We conclude that pretreatment with small-dose ketamine significantly attenuates withdrawal movements associated with IV injection of rocuronium in pediatric patients anesthetized with thiopental. IMPLICATIONS: Pretreatment with small-dose ketamine 0.2 mg/kg provides a simple and safe means of reducing the incidence of withdrawal movements induced by the injection of rocuronium, a short-acting nondepolarizing muscle relaxant.

Androstanols↗
PubMed2003

Chemical burn caused by povidone-iodine alcohol solution--a case report.

Burns associated with chemical disinfectants for skin preparation are rare. Skin irritation and maceration associated with pressure factors may contribute to its occurrence. We report a 24-year-old female with thyroid tumor who was admitted for subtotal thyroidectomy. After anesthetic induction, the patient was placed in the supine position with the trunk elevated to 20 degree. The skin over the anterior neck was sterilized with 10% Povidone-iodine (PI) alcohol solution. After a 3-hour surgery, the patient complained of burning pain over the back at the recovery room. Physical examination revealed a 9 x 11 cm area of skin lesion partially thickened amid on the middle of the back suggestive of chemical burn. After conservative treatment, she was discharged uneventfully 4 days later. Upon follow-up, the wound was seen to heal with minimal scarring within 3 weeks.

Adult↗
PubMed2003

Propofol inhibits neuronal firing activities in the caudal ventrolateral medulla.

BACKGROUND: Propofol is a potent intravenous anesthetic. The action of propofol on the medullary depressor area, the caudal ventrolateral medulla (CVLM), has not been well established. We therefore performed extracellular recordings to study the neuronal activity of the CVLM in cats before and after intravenous propofol administration, to investigate its influence on neuronal firings. METHODS: Experiments were performed on 31 cats anaesthetized with a mixture of alpha-chloralose and urethane administered intraperitoneally. Mean systemic arterial pressure, heart rate, and the neuronal firing (NF) rate were continuously recorded before and after intravenous injection of a single dose of 2 mg x kg(-1) propofol or separate supplemental doses of 1, 2, and 4 mg x kg(-1) propofol until those parameters had returned to the premedication level. RESULTS: Propofol dose-dependently and reversibly inhibited the NF rate after the supplemental doses of 1, 2, and 4 mg x kg(-1) propofol. The control NF rate of 17.9 +/- 8.6 Hz was depressed to 15.8 +/- 8.5 Hz after the first dose of propofol (p < 0.05 vs. the control), and was further depressed to 12.8 +/- 8.3 Hz (p < 0.05 vs. the control) and 10.0 +/- 7.9 Hz (p < 0.05 vs. the control) after the second and the third doses of propofol, respectively. CONCLUSION: The dose-dependent inhibition of the spontaneous neuronal firing rate is the main pharmacological action of propofol in the caudal ventrolateral medulla of cats.

Anesthetics, Intravenous↗
PubMed2002

Rocuronium-induced generalized spontaneous movements cause pulmonary aspiration.

Rapid-sequence induction with cricoid pressure is a standard procedure for inducing anesthesia in patients with a potentially full stomach. During the induction period, if the patient develops generalized movements of the body, the pressure level of the cricoid may change unexpectedly. As a result, the increase in intragastric pressure may cause gastric regurgitation and consequent pulmonary aspiration. Rocuronium has been widely used as an alternative to succinylcholine during the induction of anesthesia. However, most patients who received rocuronium complained of severe burning pain in their arm during intravenous injection. Even after the administration of the induction agents, rocuronium injection can also cause withdrawal of the hand or other generalized movements of the body. We describe a case of gastric regurgitation with pulmonary aspiration following generalized spontaneous movements associated with rocuronium injection in a girl who received pediatric emergent surgery.

Androstanols↗