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Biomedical subjects

T J Gan

Publications and source records attributed to T J Gan.

45 records · Page 3Linked to original sources
PubMed1997

Postoperative nausea and vomiting. A retrospective analysis in patients undergoing elective craniotomy.

Nausea and vomiting are important complications after craniotomy, for which there are little published epidemiologic data. We retrospectively examined the incidence of postcraniotomy nausea and vomiting to define risk factors. Medical records from 199 adults undergoing elective craniotomy were identified. Data extracted from surgery and the initial 48 hours postoperatively included gender, age, supratentorial versus infratentorial craniotomy, type of anesthesia (general versus monitored anesthesia care), intraoperative fentanyl dose, duration of anesthesia, antiemetic administration intraoperatively and postoperatively, and incidence of postoperative nausea, emesis, and opioid use. Postoperative nausea was recorded in 99 patients (50%) and emesis in 78 patients (39%). Postoperative opioids were administered to 170 patients (85%). Antiemetics were given intraoperatively to 13 patients (7%) and postoperatively to 121 patients (61%). More women (61%) than men (37%) had nausea (P = 0.001); emesis (women = 46%; men = 31%, P = 0.03); and postoperative antiemetic use (women = 69%; men = 51%, P = 0.013). The incidence of postoperative nausea (P = 0.04) and vomiting (P = 0.06) was greater in patients having infratentorial surgery. Emesis was more frequent in younger patients (P = 0.03). Postoperative nausea and vomiting were independent of anesthetic duration, fentanyl dose, or postoperative opioid use and occurred with similar frequency after general anesthesia or monitored anesthesia care. We conclude that postoperative nausea and vomiting occur frequently after craniotomy. Infratentorial surgery, female gender, and younger age are significant risk factors for this complication.

Adolescent↗
PubMed1996

A comparison of mivacurium dosage requirements during isoflurane and desflurane anesthesia.

STUDY OBJECTIVE: To evaluate the dose requirement and recovery characteristics of mivacurium infusions during anesthesia with equipotent concentrations of either desflurane or isoflurane. DESIGN: Randomized, open-study comparing the effects of desflurane and isoflurane on mivacurium-induced neuromuscular blockade. SETTING: Operating suite of a university-affiliated medical center. PATIENTS: 41 ASA status I, II, and III adult patients, requiring more than 45 minutes of neuromuscular blockade for surgery. INTERVENTIONS: Following a standardized induction sequence and established steady desflurane-nitrous oxide (DES group) or isoflurane-nitrous oxide (ISO group) anesthesia at 1 minimum alveolar concentration (MAC), an intubating dose of 0.2 mg/kg of mivacurium chloride was administered. Ventilation was maintained with a face mask until the first twitch (T1) of the evoked train-of-four (TOF) reached 10% or less of control when tracheal intubation was performed. T1 was allowed to return to 10% of its control value. An infusion of mivacurium at the initial rate of 5 micrograms/kg/min was then started and adjusted to maintain T1 at 10% +/- 2% of control. Within 20 minutes of completion of surgery, the mivacurium infusion was stopped, and the time for the evoked electromyograph (EMG) to return to 25% and 75% of the original baseline was noted. MEASUREMENTS AND MAIN RESULTS: Neuromuscular function was monitored continuously by an evoked EMG. The average infusion rate was 5.7 +/- 2.4 micrograms/kg/min (mean +/- SD) for DES group (n = 20) and 6.6 +/- 2.7 micrograms/kg/min for ISO group (n = 21) (p = NS). There was no change in the infusion rate of mivacurium over time for both groups. However, there was an inverse relationship in both groups between the time to recovery following a bolus dose and the subsequent mean infusion rate of mivacurium (correlation coefficient = -5.0; p < 0.005). The spontaneous recovery index (T25-75) for the two groups was identical, 11.5 +/- 4.9 min (mean +/- SD) for DES group and 11.5 +/- 7.9 min for ISO group (p = NS). CONCLUSION: There were no differences in the dose requirement and recovery indices of mivacurium during either desflurane or isoflurane-based anesthesia. Patients who took longer to recover from the bolus dose in both groups showed a subsequent reduction in dose requirements of mivacurium.

Adult↗
PubMed1996

Double-blind, randomized comparison of ondansetron and intraoperative propofol to prevent postoperative nausea and vomiting.

BACKGROUND: Breast surgery is associated with a high incidence of postoperative nausea and vomiting. Propofol and prophylactic administration of ondansetron are associated with a lower incidence of postoperative nausea and vomiting. To date no comparison of these two drugs has been reported. A randomized study was done to compare the efficacy of ondansetron and intraoperative propofol given in various regimens. METHODS: Study participants included 89 women classified as American Society of Anesthesiologists physical status 1 or 2 who were scheduled for major breast surgery. Patients were randomly assigned to one of four groups. Group O received 4 mg ondansetron in 10 ml 0.9% saline and groups PI, PIP, and PP received 10 ml 0.9% saline before anesthesia induction. Group O received thiopental, isoflurane, nitrous oxide-oxygen, and fentanyl for anesthesia. Group PI received propofol, isoflurane, nitrous oxide-oxygen, and fentanyl. Group PIP received propofol, isoflurane, nitrous oxide-oxygen, and fentanyl. Thirty minutes before expected skin closure, isoflurane was discontinued and 50 to 150 micrograms.kg-1.min-1 propofol was given intravenously to maintain anesthesia. Group PP received propofol for induction and maintenance of anesthesia, nitrous oxide-oxygen, and fentanyl. Postoperative pain relief was provided with morphine administered by a patient-controlled analgesia pump. The incidence of nausea and vomiting, requests for rescue antiemetic and sedation, pain scores, and hemodynamic data were recorded for 24 h. RESULTS: Within 6 h of surgery, groups O and PP had a lower incidence of nausea compared with groups PI and PIP (P < 0.05). Fewer patients in group PP (19%) vomited during the 24-h period compared with groups O (48%), PI (64%), and PIP (52%) (P < 0.05). The incidence of antiemetic use was also less in group PP (P < 0.05). Patients in group PP had lower sedation scores at 30 min and at 1 h (P < 0.05). There were no differences among the groups in pain scores, blood pressure, heart rate, respiratory rate, and incidence of pruritus. CONCLUSIONS: Propofol administered to induce and maintain anesthesia is more effective than ondansetron (with thiopental-isoflurane anesthesia) in preventing postoperative vomiting and is associated with fewer requests for rescue antiemetic and sedation in the early phase of recovery. It is equally effective in preventing postoperative nausea as ondansetron in the first 6 h after operation. Propofol used only as an induction agent or for induction and at the end of surgery were not as protective against postoperative nausea and vomiting.

Adult↗
PubMed1995

Comparison of different methods of administering droperidol in patient-controlled analgesia in the prevention of postoperative nausea and vomiting.

We performed a double-blind, placebo-controlled study to evaluate the different methods of administering droperidol in patients using patient-controlled analgesia (PCA) with morphine. Eighty patients undergoing major orthopedic procedures received temazepam 0.2 mg/kg orally followed by induction of general anesthesia with propofol 2.5 mg/kg, fentanyl 2 micrograms/kg, and vecuronium 0.1 mg/kg. Anesthesia was maintained with nitrous oxide, oxygen, and enflurane. At the end of surgery, all patients received PCA with morphine (0.5 mg/mL, bolus dose 1 mg, and lockout interval 5 min. Before commencement of PCA, patients were randomized to receive droperidol 1.25 mg immediately and, in addition, droperidol 0.16 mg with each PCA dose (Group 1), droperidol 1.25 mg immediately (Group 2), droperidol 0.16 mg with each PCA dose (Group 3), and no droperidol (Group 4). Incidence of nausea and vomiting, request for rescue antiemetics, sedation score, and side effects were recorded every 4 h. Droperidol significantly reduced the incidence of postoperative nausea and vomiting (PONV) (P < 0.01) and request for rescue antiemetic (P < 0.01) compared to placebo. However, there was no difference in the incidence of PONV between droperidol given either as a single dose at the end of surgery (Group 2) or mixed in morphine PCA (Group 3). The addition of droperidol in PCA after an initial dose (Group 1) should be avoided, as it resulted in more sedation and no further reduction in the incidence of PONV compared to Groups 2 and 3.

Adolescent↗
PubMed1994

Phaeochromocytoma presenting as acute hyperamylasaemia and multiple organ failure.

Phaeochromocytoma may present in many different ways. We report an unusual presentation of phaeochromocytoma in a man with hyperamylasaemia and multiple organ failure thought to be due to acute relapsing pancreatitis. Abdominal ultrasound and computerised tomography (CT) examinations revealed a mass at the tail of the pancreas. Fine needle biopsy of the mass precipitated headache, intense vasoconstriction and labile blood pressure. He proceeded to laparotomy, at which an 8 x 9 cm mass was found to be replacing the left adrenal gland. Histological examination revealed a phaeochromocytoma. This case illustrates that hyperamylasaemia and multiple organ failure may be unusual presentations of phaeochromocytoma and may be unusual presentations of phaeochromocytoma and phaeochromocytoma should be considered in the differential diagnosis of a peripancreatic mass found by ultrasound or CT.

Acute Disease↗
PubMed1994

Double-blind comparison of ondansetron, droperidol and saline in the prevention of postoperative nausea and vomiting.

We have compared the efficacy of ondansetron with droperidol and saline in the prevention of postoperative nausea and vomiting (PONV) in 120 ASA I and II patients undergoing hip and knee replacements and femoral resections. They received a standardized combined extradural and general anaesthetic and at the end of surgery were allocated randomly to receive droperidol 1.25 mg, ondansetron 4 mg or 0.9% saline in a 25-ml bag. An extradural mixture containing 0.5% plain bupivacaine 10 ml, fentanyl 500 micrograms and saline 30 ml was infused and PONV assessed for 24 h. Both ondansetron and droperidol were superior to saline in preventing vomiting (P < 0.01) although there was no significant difference between them. The incidence of vomiting was 17% for ondansetron, 18% for droperidol and 45% for saline. There was no significant difference in the incidence of nausea between the groups. Metoclopramide, the rescue antiemetric, was demanded by 38%, 34% and 17% of patients receiving saline, droperidol and ondansetron, respectively (ondansetron vs droperidol P < 0.05).

Adolescent↗