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Biomedical subjects

Tong J Gan

Publications and source records attributed to Tong J Gan.

At least 19 recordsLinked to original sources
PubMed2006

Gabapentin and postoperative pain--a systematic review of randomized controlled trials.

The objective of this systematic review was to evaluate the efficacy and tolerability of perioperative gabapentin administration for the control of acute postoperative pain. We searched Medline (1966-2006), the Cochrane Library (2006), Scopus, CINAHL and bibliographies from clinical trials and review articles. We included randomized controlled trials (RCTs) comparing gabapentin with inactive controls in surgical patients. Sixteen valid RCTs were included. Weighted mean difference (WMD) for postoperative pain intensity (0-100 mm visual analogue scale) was -16.55 mm at 6 h and -10.87 mm at 24 h for treatment with a single preoperative dose of gabapentin 1200 mg. Cumulative opioid consumption at 24 h was also significantly decreased with gabapentin (WMD, -27.90 mg). When gabapentin was administered at doses less than 1200 mg, pain intensity was also lower at 6 h (WMD, -22.43 mm) and 24 h (WMD, -13.18 mm). Cumulative 24 h opioid consumption was also lower (WMD, -7.25 mg). Gabapentin was associated with an increased risk of sedation (Peto OR 3.86; 95% CI 2.50-5.94) but less opioid-related side effects such as vomiting (Peto OR 0.58; 95% CI 0.39-0.86) and pruritus (Peto OR 0.27; 95% CI 0.10-0.74). In conclusion, gabapentin has an analgesic and opioid-sparing effect in acute postoperative pain management when used in conjunction with opioids.

Acute Disease↗
PubMed2006

Meta-analysis of the safety of 5-HT3 antagonists with dexamethasone or droperidol for prevention of PONV.

BACKGROUND: Antiemetic guidelines recommend a combination of serotonin (5-HT3) with a second agent such as droperidol or dexamethasone. Physicians have been reluctant to employ these guidelines due to concerns over the black-box warning of droperidol and safety concerns with a steroid. OBJECTIVE: To assess the safety profiles of 5-HT3 receptor antagonist (5-HT3RA) monotherapy and combination therapy with a steroid or droperidol for prophylaxis of postoperative nausea and vomiting (PONV). METHODS: A MEDLINE search of English-language reports of randomized controlled trials (RCTs) was conducted (1966-September 2005) using the key terms 5-HT3, granisetron, ondansetron, dolasetron, tropisetron, PONV, postoperative, vomiting, emesis, and nausea. RCTs with treatment arms comparing 5-HT3RA monotherapy (granisetron, ondansetron, dolasetron, or tropisetron) with dexamethasone or droperidol or 5-HT3RA combinations and providing incidence data on adverse events were identified and reviewed. Within-study odds ratios with 95% confidence intervals were calculated to determine the incidence rates of all adverse events in RCTs using 5-HT3RA monotherapy and combination therapies. Overall effect sizes for frequently reported adverse events were estimated by pooling ORs using fixed- and random-effect models. RESULTS: Pooled ORs (OR(pooled)) for adverse events with 5-HT3RA/dexamethasone versus 5-HT3RA for PONV prophylaxis were not significant for any reported adverse events or the overall incidence of adverse events; 5-HT3RA/droperidol versus 5-HT3RA was significant only for decreased headache incidence (fixed model: OR(pooled) 0.35; 95% CI 0.18 to 0.69). The OR(pooled) for 5-HT3RA/dexamethasone versus dexamethasone was not significant for any reported adverse events except headaches (fixed model OR(pooled) 1.75; 95% CI 1.01 to 3.03), none of which was serious. OR(pooled) for 5-HT3RA/droperidol versus droperidol was not significant for any reported adverse events. Avascular necrosis, occult infection, and delayed wound healing were not observed with either combination therapy. Cardiac abnormalities were observed with 5-HT3RA/droperidol therapy. CONCLUSIONS: This meta-analysis indicates that either therapy has a safety profile similar to that of dexamethasone, droperidol, or 5-HT3RA.

Antiemetics↗
PubMed2006

Radical perineal prostatectomy for treatment of localized prostate cancer in obese and nonobese patients: a matched control study.

OBJECTIVES: To compare the perioperative outcomes of severely obese and nonobese patients undergoing radical perineal prostatectomy (RPP). METHODS: A cohort of 71 severely obese patients, as defined by a body mass index of 35 kg/m2 or more, who underwent RPP between 1992 and 2003 was retrospectively identified. These patients were matched by age, American Society of Anesthesiologists class, and year of surgery to a cohort of 71 nonobese patients (body mass index less than 25 kg/m2). Statistical testing was performed to compare the estimated blood loss, transfusion requirements, and complication rates (primary endpoints), as well as the length of surgery, intraoperative anesthesia requirements, postoperative hematocrit level, length of stay, and surgical margin status (secondary endpoints). RESULTS: The mean body mass index +/- standard deviation of patients in the obese and nonobese group was 38.9 +/- 4.7 and 22.9 +/- 1.6 kg/m2 (P = 0.001), respectively. Patients were similar with regard to baseline characteristics. Obese and nonobese patients did not demonstrate significant differences in mean estimated blood loss (571 +/- 391 and 494 +/- 317 mL, respectively; P = 0.06), transfusion rates (2.8% and 7.0%, respectively; P = 0.45), or positive surgical margin rates (14.1% and 9.9%, respectively; P = 0.22). The overall complication rates were significantly different at 16.9% and 7.0% (P = 0.03). CONCLUSIONS: Severely obese patients undergoing RPP had blood transfusion rates similar to those of the nonobese patients. Obese RPP patients were at increased risk of surgical and anesthesia-related perioperative complications, many of which might be avoidable. Specifically, efforts should be directed toward preventing the development of lower extremity neurapraxia by minimizing the operative time and optimizing patient positioning.

Cohort Studies↗
PubMed2006

The kaolin-activated Thrombelastograph predicts bleeding after cardiac surgery.

OBJECTIVE: The objective of this study was to determine the relationship of the kaolin-activated Thrombelastograph (TEG) with postoperative bleeding and laboratory tests of coagulation in the setting of cardiac surgery with the routine use of -aminocaproic acid. DESIGN: Prospective observational study. SETTING: An adult heart center at a tertiary referral, university hospital. PARTICIPANTS: Thirty adult cardiac surgical patients. INTERVENTIONS: The kaolin-activated TEG, platelet counts, prothrombin times, activated partial thromboplastin times, and fibrinogen levels were measured before induction of anesthesia, during cardiopulmonary bypass, and on arrival in the intensive care unit. Mediastinal and thoracostomy drainage were measured every hour for 4 hours after arrival in the intensive care unit. MEASUREMENTS AND MAIN RESULTS: Correlation and multivariate linear regression modeling were used to describe relationships among coagulation tests, TEG parameters, and early postoperative bleeding. The TEG maximum amplitude (MA) parameter correlated well with postoperative bleeding (r = -0.6, p = 0.0018), more so than platelet count (r = -0.45, p = 0.02), fibrinogen level (r = -0.40, p = 0.06), or prothrombin time (r = 0.43, p = 0.02). The receiver operating characteristic curve c-index describing MA as a predictor for postoperative bleeding is 0.78. Abnormalities in all the laboratory test results were associated with an abnormal MA. CONCLUSIONS: In conclusion, the kaolin-activated TEG is associated with early coagulopathic bleeding. It may reflect the severity of a global coagulopathy affecting both platelets and coagulation factors and be a guide to incremental prohemostatic therapy in this setting.

Aged↗
PubMed2006

Postoperative nausea and vomiting following inpatient surgeries in a teaching hospital: a retrospective database analysis.

OBJECTIVE: To report the incidence of postoperative nausea and vomiting (PONV), to describe the use of anti-emetics both for the prophylaxis and treatment of PONV, and to assess resource utilization and duration of post-anesthesia care unit (PACU) stay. RESEARCH DESIGN AND METHODS: We retrieved data from the Duke Anesthesia Peri-operative database. We included adult patients, who underwent inpatient surgery under general anesthesia with inhaled agents between January 2004 and February 2005, and had two or more risk factors for PONV documented preoperatively (female, previous history of PONV or motion sickness, non-smoker or use of postoperative opioid). Data on the use of prophylactic anti-emetics, the incidence of PONV, nausea scores, pain scores, and the use of rescue anti-emetics in PACU and in the period between PACU discharge and 24 h after surgery were recorded. Resource utilization and cost assessment was performed from the perspective of the hospital and included length and direct cost of PACU stay, as well as the acquisition costs of rescue anti-emetics in PACU. Descriptive statistics were used to summarize the demographic characteristics of patients. For group comparisons, data were analyzed with the t-test for continuous data, and the Chi-square test for categorical data. Multiple linear regression models were used to evaluate the association between PONV and PACU length of stay adjusting for confounding factors. RESULTS: A total of 3641 patients were included in the analysis. Of those, 2869 (79%) received prophylactic anti-emetics. In the PACU, nausea and vomiting were reported in 16% and 3% of the patients, respectively. Rescue anti-emetics were given to 26% of all patients. The incidence of vomiting was significantly less in patients who received PONV prophylaxis (p = 0.03). In multiple linear regression models, the duration of PACU stay was longer by a mean of 25 min in patients who experienced PONV or received rescue anti-emetics in PACU (p < 0.0001) despite the fact that the duration of surgery was shorter by a mean of 24 min in this group of patients (p < 0.0001). Following PACU discharge, 40% of patients reported nausea, vomiting or needed rescue anti-emetics. PONV was associated with significantly increased resource utilization and costs of PACU stay (p < 0.0001). Emesis was associated with greater incremental cost (138 US dollars) than nausea (85 US dollars), mainly from the longer duration of PACU stay. CONCLUSIONS: PONV remain a significant problem postoperatively and often persists beyond PACU discharge. The presence of PONV is associated with increased length of PACU stay and greater resource utilization and costs.

Adult↗
PubMed2006

Transcutaneous acupoint electrical stimulation with the ReliefBand for the prevention of nausea and vomiting during and after cesarean delivery under spinal anesthesia.

We randomized 94 patients undergoing cesarean delivery with spinal anesthesia to receive transcutaneous acupoint electrical stimulation using the ReliefBand at the P6 point (active group) or an active ReliefBand applied to the dorsum of the wrist (sham control group). The ReliefBand was applied 30-60 min preoperatively and left in place for 24 h. There was no statistically significant difference between the active and sham control groups in the incidence of intraoperative/postoperative nausea (30% versus 43%/23% versus 41%), vomiting (13% versus 9%/26 versus 37%), need for rescue antiemetics (23% versus 18%/34% versus 39%), or complete response (55% versus 57%/51% versus 34%). There was also no difference between the two groups in nausea scores, number of vomiting episodes, or patient satisfaction with postoperative nausea and vomiting management.

Acupuncture Points↗
PubMed2006

Use of a modifier reduces inconsistency in the American Society of Anesthesiologists Physical Status Classification in parturients.

In this study, we sought to determine whether there is a significant discrepancy among a group of practitioners when rating pregnant patients using the ASA Physical Status Classification and whether this discrepancy could be resolved with the addition of a modifier for pregnancy. Our results indicate that significant discrepancy occurs and that it is reduced with the use of the modifier, especially when referring to the healthy parturient.

Anesthesiology↗
PubMed2006

Risk factors for postoperative nausea and vomiting.

Knowledge of postoperative nausea and vomiting (PONV) risk factors allows anesthesiologists to optimize the use of prophylactic regimens. Modern PONV risk research began in the 1990s with publication of studies using logistic regression analysis to simultaneously identify multiple independent PONV predictors and publication of meta-analyses and systematic reviews. This literature shows that female gender post-puberty, nonsmoking status, history of PONV or motion sickness, childhood after infancy and younger adulthood, increasing duration of surgery, and use of volatile anesthetics, nitrous oxide, large-dose neostigmine, or intraoperative or postoperative opioids are well established PONV risk factors. Possible risk factors include history of migraine, history of PONV or motion sickness in a child's parent or sibling, better ASA physical status, intense preoperative anxiety, certain ethnicities or surgery types, decreased perioperative fluids, crystalloid versus colloid administration, increasing duration of anesthesia, general versus regional anesthesia or sedation, balanced versus total IV anesthesia, and use of longer-acting versus shorter-acting opioids. Early-phase menstruation, obesity and lack of supplemental oxygen are disproved risk factors. Current risk scoring systems have approximately 55%-80% accuracy in predicting which patient groups will suffer PONV. Further research examining genetic and under-investigated clinical patient characteristics as potential risk factors, and involving outpatients and children, should improve predictive systems.

Humans↗
PubMed2006

Pharmacokinetic and pharmacodynamic characteristics of medications used for moderate sedation.

The ability to deliver safe and effective moderate sedation is crucial to the ability to perform invasive procedures. Sedative drugs should have a quick onset of action, provide rapid and clear-headed recovery, and be easy to administer and monitor. A number of drugs have been demonstrated to provide effective sedation for outpatient procedures but since each agent has its own limitations, a thorough knowledge of the available drugs is required to choose the appropriate drug, dose and/or combination regimen for individual patients. Midazolam, propofol, ketamine and sevoflurane are the most frequently used agents, and all have a quick onset of action and rapid recovery. The primary drawback of midazolam is the potential for accumulation of the drug, which can result in prolonged sedation and a hangover effect. The anaesthetics propofol and sevoflurane have recently been used for sedation in procedures of short duration. Although effective, these agents require monitored anaesthesia care. Ketamine is an effective agent, particularly in children, but there is concern regarding emergence reactions. AQUAVAN injection (fospropofol disodium), a phosphorylated prodrug of propofol, is an investigational agent possessing a unique and distinct pharmacokinetic and pharmacodynamic profile. Compared with propofol emulsion, AQUAVAN is associated with a slightly longer time to peak effect and a more prolonged pharmacodynamic effect. Advances in the delivery of sedation, including the development of new sedative agents, have the potential to further improve the provision of moderate sedation for a variety of invasive procedures.

Anesthesia Recovery Period↗
PubMed2006

Use of neostigmine in the management of acute postoperative pain and labour pain: a review.

Neostigmine is a parasympathomimetic agent that has been recently investigated for use as an adjunct analgesic agent in the perioperative and peripartum period. A number of studies have investigated the intrathecal, epidural, caudal and intra-articular routes of administration of this agent, as well as the addition of neostigmine to local anaesthetics used for brachial plexus block and intravenous regional anaesthesia. While the intrathecal administration of neostigmine produced useful analgesic effects in the postoperative period in some studies, the high incidence of adverse events, mainly nausea and vomiting, limit the clinical usefulness of this route of administration. Several studies investigated the postoperative analgesic effects of epidural neostigmine using a number of different regimens. Overall, this route of administration appeared to improve postoperative analgesia in most studies without increasing the incidence of adverse events, and merits further research. Neuraxial administration of neostigmine appears to be safe in the obstetric population, with no reported adverse effects in the mother or fetus. While intrathecal administration is limited by a high incidence of nausea and vomiting in this patient population, the epidural route appears more promising and requires further investigation. The addition of neostigmine to caudal local anaesthetics was associated with improved postoperative analgesia in a number of studies. A dose of 2 microg/kg proved to be effective in several studies but was associated with an increased incidence of vomiting in some studies. Intra-articular administration of neostigmine 500microg produced a useful analgesic effect in the postoperative period in several studies and was not associated with an increase in the incidence of adverse effects. Studies investigating the efficacy of adding neostigmine to the local anaesthetics used for brachial plexus block and intravenous regional anaesthesia reported conflicting results. Further studies are required to determine the place of the administration of neostigmine by these routes.

Anesthesia, Conduction↗
PubMed2005

Role of analgesic adjuncts in postoperative pain management.

Postoperative pain remains a major problem. A multi-modal analgesic approach is recommended to optimize pain management and reduce opiate-related adverse effects. Several analgesic adjuncts have been investigated, and many have proved to have a useful analgesic effect. This article reviews the literature regarding use of analgesic adjuncts in the perioperative period.

Adrenal Cortex Hormones↗
PubMed2005

The effectiveness of rescue antiemetics after failure of prophylaxis with ondansetron or droperidol: a preliminary report.

STUDY OBJECTIVES: To compare the effectiveness of treating established postoperative nausea and vomiting (PONV) with an antiemetic acting at a different receptor with that of treating PONV with the antiemetic used for prophylaxis. DESIGN: Analysis of data collected in a previously published randomized, double-blind, placebo-controlled study. SETTING: Outpatient surgical procedures from 50 institutions in North America. PATIENTS: Patients (N = 2061) undergoing outpatient surgical procedures planned to last no more than 2 hours. INTERVENTIONS: Patients were randomized to receive ondansetron 4 mg, droperidol 1.25, droperidol 0.625 mg, or placebo. In the postoperative anesthesia care unit, patients who developed PONV received rescue antiemetics at the discretion of the attending anesthesiologist. The following antiemetics were used for rescue: ondansetron 4 mg, droperidol 0.625 to 1.25 mg, metoclopramide 10 mg, promethazine 6.25 to 25 mg, and dimenhydrinate 25 to 50 mg. MEASUREMENTS: The complete response rate (no nausea, no emesis, and no need for further rescue) after administration of the rescue antiemetic in patients with established PONV was calculated. The complete response rate after administration of each of the different rescue antiemetics was compared with that after administration of the same antiemetic used for PONV prophylaxis. MAIN RESULTS: In patients who failed prophylaxis with ondansetron 4 mg, the complete response rate was significantly higher (P = .02) after rescue with promethazine 6.25 to 25 mg (78%) than after rescue with ondansetron 4 mg (46%). In patients who failed prophylaxis with droperidol 0.625 and 1.25 mg, the complete response rate was significantly higher after rescue with promethazine 6.25 to 25 mg (77%; P = .02) and dimenhydrinate 25 to 50 mg (78%; P = .04) than after rescue with droperidol 0.625 to 1.25 mg (56%). CONCLUSION: In patients who failed prophylaxis with ondansetron or droperidol, promethazine was significantly more effective than the agent used for prophylaxis for the treatment of PONV. In patients who failed prophylaxis with droperidol, dimenhydrinate was also more effective than droperidol for the treatment of established PONV in the postoperative anesthesia care unit.

Adult↗
PubMed2005

Radical perineal prostatectomy for the treatment of localized prostate cancer in morbidly obese patients.

PURPOSE: We assessed the feasibility of radical perineal prostatectomy (RPP) in morbidly obese patients with clinically organ confined prostate cancer. MATERIALS AND METHODS: Of 1,265 consecutive patients who underwent RPP at our institution from 1992 to 2003 we identified 18 with a body mass index (BMI) of 40 kg/m or greater. Demographic and clinical patient characteristics were obtained from the medical records, which were further reviewed to identify the perioperative incidence of surgical and anesthesia related complications. RESULTS: Median BMI was 41.7 kg/m (range 40.2 to 62.6). Five patients had a BMI of 45.0 kg/m or greater. No intraoperative or anesthesia related complication occurred. Mean operative time +/- SD was 188 +/- 32 minutes and estimated blood loss was 573 +/- 285 ml. None of the 18 patients received blood transfusions. During the immediate postoperative period 4 complications occurred in the form of lower extremity neuropraxia in 2 patients, local skin bleeding in 1 and early sepsis in 1 requiring rehospitalization for intravenous antibiotics. Mean operative time and estimated blood loss were significantly lower when surgery was performed by a highly experienced surgeon compared with experienced surgeons (174 +/- 21 vs 235 +/- 10 minutes and 485 +/- 258 vs 838 +/- 197 ml, p = 0.001 and 0.027, respectively). CONCLUSIONS: RPP in morbidly obese patients is feasible and it is associated with acceptable perioperative morbidity. The perineal approach should be considered in morbidly obese patients seeking surgical treatment for clinically localized prostate cancer.

Humans↗
PubMed2005

Perioperative fluid management and clinical outcomes in adults.

The administration of IV fluid to avoid dehydration, maintain an effective circulating volume, and prevent inadequate tissue perfusion should be considered, along with the maintenance of sleep, pain relief, and muscular relaxation, a core element of the perioperative practice of anesthesia. Knowledge of the effects of different fluids has increased in recent years, and the choice of fluid type in a variety of clinical situations can now be rationally guided by an understanding of the physicochemical and biological properties of the various crystalloid and colloid solutions available. However, there are few useful clinical outcome data to guide this decision. Deciding how much fluid to give has historically been more controversial than choosing which fluid to use. A number of clinical studies support the notion that an approach based on administering fluids to achieve maximal left ventricular stroke volume (while avoiding excess fluid administration and consequent impairment of left ventricular performance) may improve outcomes. In this article, we review the available fluid types and strategies of fluid administration and discuss their relationship to clinical outcomes in adults.

Adult↗
PubMed2005

A randomized, double-blind study of granisetron plus dexamethasone versus ondansetron plus dexamethasone to prevent postoperative nausea and vomiting in patients undergoing abdominal hysterectomy.

In this randomized, double-blind study, we evaluated whether small-dose granisetron (0.1 mg) plus dexamethasone 8 mg (G+D) was as effective as ondansetron 4 mg plus dexamethasone 8 mg (O+D) for preventing vomiting during the 0 to 2 h after tracheal extubation in patients undergoing abdominal hysterectomy requiring general anesthesia. Dexamethasone (D) was administered at induction of anesthesia, and granisetron (G) or ondansetron (O) was given approximately 15 min before tracheal extubation. Data on postoperative nausea and vomiting were collected at 0, 2, 6, and 24 h. For the primary efficacy endpoint, most patients in each group had no vomiting in the 0- to 2-h interval (82/87 [94%] for G+D versus 86/89 [97%] for O+D). Effectiveness of G+D was demonstrated versus O+D. Treatment groups were similar with regard to moderate or severe nausea, complete response, rescue medication use, and total control over 24 h. A descriptive assessment of adverse events showed that both combinations were well tolerated with infrequent and similar incidences of adverse events. The combination of small-dose G administered just before tracheal extubation plus D given at induction of anesthesia is an effective alternative to O+D in preventing vomiting during the 0- to 2-h interval after tracheal extubation.

Adult↗
PubMed2005

Selective serotonin 5-HT3 receptor antagonists for postoperative nausea and vomiting: are they all the same?

Selective serotonin 5-HT(3) receptor antagonists have proven safe and effective for the management of postoperative nausea and vomiting. Dolasetron, granisetron, ondansetron and tropisetron selectively and competitively bind to 5-HT(3) receptors, blocking serotonin binding at vagal afferents in the gut and in the regions of the CNS involved in emesis, including the chemoreceptor trigger zone and the nucleus tractus solitarii. Despite their shared mechanism of action, 5-HT(3) receptor antagonists have different chemical structures and exhibit differences in receptor binding affinity, dose response and duration of effect. Furthermore, although dolasetron, granisetron, ondansetron and tropisetron are all extensively metabolised by the cytochrome P450 (CYP) system, different components of this system predominate in the metabolism of each of these agents. Hence, although these agents are considered equally effective in the overall population, their pharmacokinetic and pharmacodynamic differences may explain the variability in individual responses to these drugs. This review discusses the pharmacological profiles of dolasetron, granisetron, ondansetron and tropisetron, and the clinical implications of differences in their profiles.

Antiemetics↗
PubMed2004

The efficacy of the 5-HT3 receptor antagonists combined with droperidol for PONV prophylaxis is similar to their combination with dexamethasone. A meta-analysis of randomized controlled trials.

PURPOSE: The aim of this quantitative systematic review is to compare the efficacy and side effects of combining one of the 5-HT(3) receptor antagonists (5-HT) with droperidol or dexamethasone for postoperative nausea and vomiting (PONV) prophylaxis. METHODS: We performed a systematic search (Medline, Embase, and the Cochrane Library) for randomized controlled trials that compared the antiemetic efficacy of combining one of the 5-HT with droperidol or dexamethasone vs 5-HT alone. Relevant endpoints were prevention of early (0 to 6 hr), and overall (0 to 24 hr) PONV, and side effects. The articles that could meet the inclusion criteria were scored for inclusion and methodological validity using the three-item, five-point, Oxford-scale. Relative risk and numbers needed-to-treat with 95% confidence intervals were calculated for each combination vs 5-HT alone. The two combinations were then indirectly compared. A random effects model was used. RESULTS: We considered 41 trials for analysis but subsequently excluded eight. Thirty-three trials with data from 3,447 patients were analyzed. Except for early nausea with the 5-HT plus droperidol, both combinations were significantly more effective than 5-HT in preventing early and overall PONV. There was no difference in antiemetic efficacy between the two combinations. The incidence of commonly reported side effects was also similar in the two combination groups. CONCLUSION: We conclude that there is no statistically significant difference in antiemetic efficacy or side effects profile when one of the 5-HT is combined with either droperidol or dexamethasone and that both combination regimens are significantly more effective than 5-HT alone.

Antiemetics↗