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Wei-Zen Sun

Publications and source records attributed to Wei-Zen Sun.

35 records · Page 2Linked to original sources
PubMed2004

The absence of arterial oxygen desaturation during massive oxygen embolism after hydrogen peroxide irrigation.

For decades, water-mill murmur, decrease in end-tidal CO(2) (Petco(2)), hypotension, and hypoxemia have been accepted as diagnostic criteria for gas embolism. In this case report, a 19-yr-old male patient developed a sudden reduction in Petco(2) and profound circulatory collapse 15 min after intramedullary irrigation with H(2)O(2). However, arterial oxygen desaturation never developed throughout the entire course of resuscitation from presumed massive oxygen embolism.

Adult↗
PubMed2003

Propofol reduces nitric oxide biosynthesis in lipopolysaccharide-activated macrophages by downregulating the expression of inducible nitric oxide synthase.

Nitric oxide is an active oxidant that contributes to the physiology and pathophysiology of macrophages. Propofol has been widely used in intravenous anesthesia. It possess antioxidant and immunomodulating effects. This study aimed to evaluate the effects of propofol on nitric oxide production in lipopolysaccharide-activated macrophages. Exposure of macrophages to propofol (25, 50 and 75 micro M), to lipopolysaccharide (0.5, 1, 1.5 and 2 ng/ml) or to a combination of propofol and lipopolysaccharide did not affect cell viability. However, propofol at 100 micro M led to significant cell death ( P<0.05). The levels of nitrite, an oxidative product of nitric oxide, were increased in lipopolysaccharide-treated macrophages in a concentration-dependent manner ( P<0.01), while propofol could concentration-dependently decrease the lipopolysaccharide-enhanced nitrite levels ( P<0.01). Immunoblotting analysis revealed that lipopolysaccharide increased the protein level of inducible nitric oxide synthase (iNOS). The co-treatment of propofol and lipopolysaccharide significantly reduced this lipopolysaccharide-induced iNOS protein (357+/-49 x 10(3) versus 92+/-6 x 10(3) arbitrary units, P<0.01). Analysis by reverse transcriptase-polymerase chain reaction showed that lipopolysaccharide induced mRNA of iNOS, but that the inductive effect was inhibited by propofol (95+/-7 x 10(2) versus 30+/-4 x 10(2) arbitrary units, P<0.01). This study has demonstrated that propofol, at therapeutic concentrations, could suppress nitric oxide biosynthesis by inhibiting iNOS expression in lipopolysaccharide-activated macrophages. The mechanism of suppression was at a pretranslational level.

Animals↗
PubMed2003

Does the suggested lightwand bent length fit every patient? The relation between bent length and patient's thyroid prominence-to-mandibular angle distance.

BACKGROUND: To date, no study has explored the effect of bent length on lightwand intubation. For successful intubation in daily practice, the authors found that bent length should be approximated to the patient's thyroid prominence-to-mandibular angle distance (TMD), but some patients have a TMD much shorter than the suggested bent length range. The purposes of this study were to understand TMD distribution in adults and to test the influence of bent length on lightwand intubation. METHODS: The TMD, airway, and demographic data of 379 patients were collected. To test the bent length influence, patients were enrolled in group A (158 patients, TMD </= 5.5 cm) and group B (131 patients, TMD > 5.5 cm) and were intubated randomly using the lower (6.5 cm) and upper (8.5 cm) limits of the suggested range. Success rate and lightwand search time were compared. RESULTS: In group A, the success rate was 98.8% with 6.5-cm bent length and 78.2% with 8.5-cm bent length (P < 0.05). Search times were 5.7 +/- 2.90 and 8.9 +/- 5.80 s with 6.5- and 8.5-cm bent length, respectively (P < 0.01). In group B, there was no statistical difference in success rate and search time between 6.5- and 8.5-cm bent length. CONCLUSION: The suggested range was suitable for patients in group B (TMD > 5.5 cm). However, in group A (</=5.5 cm), the large discrepancy between the upper limit of the suggested range and this TMD caused difficulty in lightwand intubation. A 6.5-cm bent length is more suitable than an 8.5-cm bent length in these patients.

Adult↗
PubMed2003

General anesthetic management for diagnostic splenectomy in a patient with paraneoplastic pemphigus.

Paraneoplastic pemphigus (PNP) is an autoantibody-mediated mucocutaneous blistering disease that often occurs with confirmed or occult malignancy. It is often accompanied by extensive eruption of respiratory mucosa and can lead to respiratory failure. The indications for anesthetic management in patients with PNP are rare due to the high risk of generating further eruption of respiratory mucosa during intubation, with potentially disastrous consequences. We report the anesthetic management in a 43-year-old woman with PNP scheduled for diagnostic splenectomy. The surgery was postponed due to persistent hoarseness, diffuse oral-pharyngeal mucositis, and laryngeal erosion. Methylprednisolone 40 mg 3 times daily was prescribed for controlling the mucosa lesions. Two weeks later, after the improvement of mucosal lesions, direct laryngoscopic intubation and the scheduled splenectomy were performed under general anesthesia. Pathology of the spleen showed low-grade B-cell lymphoma had induced PNP. Flexible fiberoptic bronchoscopic examination revealed neither bleeding nor bullae formation in the trachea either immediately after intubation or before extubation. The tracheal mucosa is highly susceptible to mechanical stimulation with direct laryngoscopic intubation. Cuff inflation and positive pressure ventilation, awareness of the disease characteristics of PNP, a sufficient course of steroid therapy beforehand, and adequate mucosal protection are essential to the uneventful anesthetic management of the patient with PNP involving the respiratory tract mucosa.

Adult↗
PubMed2003

Nitrous oxide suppresses tonic and phasic nociceptive behaviors but not formalin-induced c-Fos expression in the rat spinal cord dorsal horn.

BACKGROUND: The aim of this study was to investigate the anesthetic and analgesic effects of subanesthetic concentration of nitrous oxide and to compare these effects with halothane and fentanyl. METHODS: The antinociceptive effects were assessed in male Sprague-Dawley rats by behavioral responses to phasic and tonic nociceptive stimulations and biochemical index of pain, formalin-induced Fos-like immunoreactivity (Fos-LI), in spinal cord dorsal horn. Neurological functions (proprioception, mental status and motor function) were monitored to determine whether or not behavioral responses were impaired by anesthetic action of the treatment. Four groups of rats treated with: (1) saline, (2) 75% nitrous oxide (0.5 MAC), (3) 0.5% halothane (0.5 MAC) and (4) fentanyl 100 micrograms/kg were subject either to graded intensity of CO2 laser stimulation (phasic pain) or s.c. injection of 50 microliters 2.5% formalin (tonic pain) in two separate studies. All rats in the tonic pain study were killed for immunohistochemistry at 60 min after formalin injection. Maximal counts of Fos-LI labelled neurons in rat spinal cord dorsal horn were compared according to the laminar distribution. RESULTS: We found that all rats exhibited normal righting reflexes regardless of whatever treatment. Nitrous oxide and halothane greatly impaired mental status and motor function, indicating that both agents could induce a modest degree of sedation and paresis at subanesthetic concentrations. Fentanyl increased the threshold level to noxious thermal stimulation, and reduced the formalin-induced licking/biting behaviors and the number of Fos-LI labelled neurons which are predominantly found in the neck of the dorsal horn. Nitrous oxide and halothane increased the thermal nociceptive threshold, suppressed licking/biting behavior in both early and late phases of the formalin test. Unlike fentanyl, nitrous oxide and halothane failed to suppress c-fos expression. The extent and pattern of nitrous oxide-induced antinociception was identical to halothane, which is known to have little or no analgesic effect. The lack of attenuated biochemical response to tonic pain stimulation may suggest that nitrous oxide fails to suppress spinal sensitization despite its potent inhibition on behavioral hyperalgesia. CONCLUSIONS: These findings suggest that, at the spinal level, subanesthetic concentration of nitrous oxide greatly attenuates nociceptive behaviors mainly due to a non-selective suppression of behavioral responses that are commonly associated with inhalation anesthetic drugs.

Anesthetics, Inhalation↗
PubMed2002

Intravenous tenoxicam reduces uterine cramps after Cesarean delivery.

PURPOSE: Postpartum uterine contraction pain is a common phenomenon after Cesarean delivery. We investigated the effectiveness of tenoxicam in reducing uterine contraction pain. METHODS: We enrolled 120 consecutive non-breastfeeding women who were scheduled for elective Cesarean delivery. After the administration of spinal anesthesia with bupivacaine and intrathecal morphine 0.15 mg injection, the patients were randomly divided into two groups. Group I received placebo (normal saline) iv injection, and Group II received tenoxicam 40 mg iv injection after clamping the umbilical cord. Verbal analogue scale of wound pain and uterine contraction pain were recorded at two, four, eight,16, and 24 hr after Cesarean delivery. RESULTS: There was no significant difference in wound pain scores between the two groups (all scores < or =3). However, the tenoxicam group had significant lower uterine contraction pain scores and required less supplemental meperidine medication than did the placebo group (8.5% vs 41.4%, P <0.05). The incidences of nausea or vomiting, pruritus, and bleeding were not significantly different between groups. CONCLUSION: Intravenous tenoxicam 40 mg significantly reduced the intensity of uterine cramps in patients undergoing Cesarean delivery without increasing side effects.

Adult↗
PubMed2002

The effect of high and low frequency electroacupuncture in pain after lower abdominal surgery.

In the present study, we examined the effects of preoperative electroacupuncture (EA) at classical bilateral acupuncture points (Zusanli, also known as ST-36) on postoperative pain and opioid-related side effects. One hundred healthy consenting women undergoing lower abdominal surgery were randomly assigned to four treatment regimens: Group I (n=25), control; Group II (n=25), sham-EA (needle insertion without electrical stimulation); Group III (n=25), low-EA (2 Hz of electrical stimulation); and Group IV (n=25), high-EA (100 Hz of electrical stimulation). EA groups received needle insertion with or without electrical stimulation 20 min prior to anesthesia. All patients received patient-controlled analgesia (PCA) of morphine postoperation. Postoperative pain was evaluated by recording (1). the time of the first required analgesic, (2). the number of PCA demands, (3). the total amount of morphine required by PCA, and (4) patients' VAS pain score. We found that the time of first analgesic requested was 10, 18, 28, and 28 min in the control, sham-, low-, and high-EA groups, respectively. During the first 24h, the total amount of morphine required was decreased by 21, 43 and 61% in the sham-, low- and high-EA groups, respectively. The incidence of nausea and dizziness during the first 24h after surgery was significantly reduced in both the low-EA and high-EA groups compared with the control and sham-EA groups. We also found that sham-EA exerts a beneficial effect with respect to its pain relieving quality but not the side effect profiles. Our findings demonstrates that preoperative treatment with low-EA and high-EA can reduce postoperative analgesic requirements and associated side effects in patients undergoing lower abdominal surgery.

Acupuncture Analgesia↗
PubMed2002

Relationship between pain-specific beliefs and adherence to analgesic regimens in Taiwanese cancer patients: a preliminary study.

This pilot cross-sectional study aimed to 1) explore pain beliefs and adherence to prescribed analgesics in Taiwanese cancer patients, and 2) examine how selected pain beliefs, pain sensory characteristics, and demographic factors predict analgesic adherence. Pain beliefs were measured by the Chinese version of Pain and Opioid Analgesic Beliefs Scale-Cancer (POABS-CA) and the Survey of Pain Attitudes (SOPA). Analgesic adherence was measured by patient self-report of all prescribed pain medicine taken during the previous 7 days. Only 66.5% of hospitalized cancer patients with pain (n = 194) adhered to their analgesic regimen. Overall, patients had relatively high mean scores in beliefs about disability, medications, negative effects, and pain endurance, and low scores in control and emotion beliefs. Medication and control beliefs significantly predicted analgesic adherence. Patients with higher medication beliefs and lower control beliefs were more likely to be adherent. Findings support the importance of selected pain beliefs in patients' adherence to analgesics, suggesting that pain beliefs be assessed and integrated into pain management and patient education to enhance adherence.

Analgesics↗
PubMed2002

The effect of IVPCA morphine on post-hysterectomy bowel function.

BACKGROUND: Although morphine has been shown to induce bowel dysfunction in a dose-dependent fashion, in most relevant studies it was investigated in single bolus injection. Recently, intravenous morphine via patient-controlled analgesia (IVPCA) has been widely used to provide analgesia by divided bolus doses on patients' demand with satisfactory effects. This approach, by reducing the peak serum surge, largely resembles the pharmacokinetic and pharmacodynamic advantage of continuous infusion. There is yet no report on the investigation of its effect on post-operative bowel dysfunction. METHODS: Fifty-one women who underwent abdominal total hysterectomy (ATH) due to uterine myoma were enrolled to investigate the association between the doses of morphine consumption by PCA and the time of first passage of flatus. In all patients morphine was administered intravenously via a PCA pump immediately after recovery from general anesthesia. RESULTS: We found that 49 out of 51 patients (96%) exhibited mild pain with IVPCA morphine. They had consumed an average dose of 16.9 mg morphine (range, 0-46 mg) upon the first passage of flatus which occurred 2036.4 min (average) post-operatively. There was no correlation between the dose of morphine and the time of first passage of flatus (r = 0.053, P > 0.05). CONCLUSIONS: The absence of suppression of bowel movement by IVPCA morphine for post-operative pain control suggests that favorable pharmacokinetic profile of IVPCA can help reduce the morphine-induced bowel dysfunction at its therapeutic level.

Adult↗
PubMed2002

An evidence-based review on the use of corticosteroids in peri-operative and critical care.

With complex and extensive pharmacological effects, corticosteroids are widely used in many clinical situations. A survey conducted to define the role of corticosteroids in various settings of peri-operative and critical care gave strong evidence to support that the use of corticosteroid is absolutely indicated in patients with adrenal insufficiency, asthma, anaphylaxis, acute spinal cord injury, and increased ICP resulting from brain tumors. As the benefits of corticosteroids are much in evidence, their uses are recommended to extend to postoperative antiemesis, acute respiratory failure (such as ARDS, COPD, and fat embolism), increased ICP associated with brain abscess, thyroid storm, and refractory hypothermia. Beneficial effect could be expected in septic shock with high-dose corticosteroids. Despite extensive reports on their versatile usefulness, evidence-based review did not recommend the use of corticosteroids in increased ICP associated with traumatic head injury and cerebral infarct, cardiac arrest, post-extubation airway edema, and aspiration pneumonia due to poor effectiveness let alone further worsening of the conditions. Great caution must be taken in clinical situations where administration of corticosteroids is considered contraindicated such as systemic fungal infection, hypersensitivity to the drug, intramuscular injection in idiopathic thrombocytopenia purpura, vaccination with live virus.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Intravenous lidocaine and ephedrine, but not propofol, suppress fentanyl-induced cough.

PURPOSE: The aim of this study was to evaluate the effectiveness of lidocaine, propofol and ephedrine in suppressing fentanyl-induced cough. METHODS: One hundred and eighteen patients were randomly assigned into four groups and the following medications were given intravenously: patients in Group I (n = 31) received normal saline 2 mL, Group II (n = 29) received lidocaine 2 mg.kg(-1), Group III (n = 30) received propofol 0.6 mg.kg(-1) and Group IV (n = 28) received ephedrine 5 mg. At one minute after the study medication, fentanyl 2.5 microg.kg(-1) was given intravenously within two seconds. The occurrence of cough and vital sign profiles were recorded within two minutes after fentanyl bolus by an anesthesiologist blinded to study design. RESULTS: Sixty-five percent of patients in the placebo group had cough, whereas the frequency was significantly decreased in Groups II (14%) and IV (21%). Although a numerically lower frequency of cough was noted in Group III (37%), it was not statistically different from that of the placebo group. SpO(2) decreased significantly in patients of Group III compared to placebo; one patient experienced hypoxemia necessitating mask ventilation. Patients in Group III showed a decrease in heart rate and systolic blood pressure (2 beats.min(-1) and 8 mmHg vs baseline). Patients in Group IV showed an increase in both measurements (5 beats.min(-1) and 8 mmHg vs baseline). No truncal rigidity was observed throughout the study. CONCLUSIONS: Intravenous lidocaine 2 mg.kg(-1) or ephedrine 5 mg, but not propofol 0.6 mg.kg(-1), was effective in preventing fentanyl-induced cough. The results provide a convenient method to decrease fentanyl-induced cough.

Adult↗
PubMedDate not supplied

Differential analgesic effect of tenoxicam on the wound pain and uterine cramping pain after cesarean section.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to enhance opioid analgesia in the acute pain service. The question, however, of whether NSAIDs produce a similar extent of potentiation among different types of pain, has not been thoroughly investigated. MATERIALS AND METHODS: A randomized, placebo-controlled, double-blind study was performed to characterize the analgesic effect of tenoxicam, a long-acting NSAID, on resting wound pain, evoked wound pain, and uterine cramping pain after cesarean section. Saline (n = 48) or 20 mg tenoxicam (n = 45) was intravenously injected immediately after clamping the umbilical cord. All patients were instructed to obtain maximal postoperative analgesia by intravenous patient-controlled morphine. RESULTS Tenoxicam profoundly reduced the intensity of uterine cramping pain (3.6 [2.0-5.6] versus 5.5 [3.4-6.6]; p < 0.01) but had no additional effect on wound pain at rest, with movement, changing position, sitting, and walking. Intraoperative injection of 20 mg tenoxicam decreased the demand ratio for patient-controlled analgesia (PCA) and 24-hour morphine consumption by approximately 30%. CONCLUSIONS: The data show that tenoxicam potentiates opioid analgesic effect on the somatic and visceral types of pain to different extents, and they suggest that intraoperative injection of 20 mg tenoxicam is sufficient to enhance intravenous PCA morphine on uterine cramping pain for the first 24 hours after cesarean section.

Adolescent↗