Dexamethasone alone versus in combination with intra-operative super-hydration for postoperative nausea and vomiting prophylaxis in female patients undergoing laparoscopic cholecystectomy: a randomized clinical trial.

BACKGROUND: Dexamethasone has a prophylactic effect on postoperative nausea and vomiting (PONV) and perioperative hydration is believed to play a role in PONV prophylaxis. This study was performed to examine the combined effects of pre-induction dexamethasone plus super-hydration on PONV and pain following laparoscopic cholecystectomy (LC). METHODS: A total of 100 female patients undergoing LC were enrolled and randomized equally into two groups. Group DF received 5 mg dexamethasone (pre-induction) plus 30 ml/kg Ringer's lactate (intraoperative) and group D received 5 mg dexamethasone (pre-induction) alone. Anesthetic and surgical managements were standardized for all patients. The incidence and severity of PONV, and intra and post-operative analgesic and postoperative antiemetic consumption, were assessed during the first 24 h postoperatively. Post-anesthesia care unit (PACU) stay and aggregated 24 h pain scores were calculated. RESULTS: Group DF had significantly lower PONV than group D (P = 0.03). The number of patients with the lowest PONV score was significantly increased in group DF (P = 0.03). Ondansetron consumption was significantly lower in group DF (P < 0.0001). The mean accumulated 24 h pain scores were significantly lower in group DF compared to group D (P < 0.0001). The time to first analgesic request was significantly longer in group DF than group D (P < 0.0001). In addition, total meperidine consumption during the first postoperative 24 h was significantly lower in group DF than group D (P = 0.002). CONCLUSIONS: In female patients undergoing LC, pre-induction with 5 mg dexamethasone plus intraoperative 30 ml/kg Ringer's lactate solution decreased PONV and pain during the first 24 h postoperatively compared to 5 mg dexamethasone alone.

Comparison of intrathecal versus intra-articular dexmedetomidine as an adjuvant to bupivacaine on postoperative pain following knee arthroscopy: a randomized clinical trial.

BACKGROUND: Postoperative pain is a common, distressing symptom following arthroscopic knee surgery. The aim of this study was to compare the potential analgesic effect of dexmedetomidine after intrathecal versus intra-articular administration following arthroscopic knee surgery. METHODS: Ninety patients undergoing unilateral elective arthroscopic knee surgery were randomly assigned into three groups in a double-blind placebo controlled study. The intrathecal dexmedetomidine group (IT) received an intrathecal block with intrathecal dexmedetomidine, the intra-articular group (IA) received an intrathecal block and intra-articular dexmedetomidine, and the control group received an intrathecal block and intra-articular saline. The primary outcome of our study was postoperative pain as assessed by the visual analogue scale of pain (VAS). Secondary outcomes included the effect of dexmedetomidine on total postoperative analgesic use and time to the first analgesic request, hemodynamics, sedation, postoperative nausea and vomiting, patient satisfaction, and postoperative C-reactive protein (CRP) levels. RESULTS: Dexmedetomidine administration decreased pain scores for 4 h in both the intrathecal and intra-articular groups, compared to only 2 h in the control patient group. Furthermore, there was a significant reduction in pain scores for 6 h in the intra-articular group. The time to the first postoperative analgesia request was longer in the intra-articular group compared to the intrathecal and control groups. The total meperidine requirement was significantly lower in the intra-articular and intrathecal groups than in the control group. CONCLUSIONS: Both intrathecal and intra-articular dexmedetomidine enhanced postoperative analgesia after arthroscopic knee surgery. Less total meperidine was required with intra-articular administration to extend postoperative analgesia to 6 h with hemodynamic stability.

Spinal versus general anesthesia for Cesarean section in patients with sickle cell anemia.

BACKGROUND: Sickle cell anemia (SCA) increases the rate of maternal and fetal complications. This pilot study was designed to compare the maternal and fetal outcomes of spinal versus general anesthesia (GA) for parturients with SCA undergoing cesarean delivery. METHODS: Forty parturients with known SCA scheduled for elective Cesarean delivery were randomized into spinal anesthesia (n = 20) and GA groups (n = 20). Perioperative hemodynamic parameters were recorded. Postpartum complications were followed up. Opioid consumption was calculated. Blood loss during surgery and the number of patients who received intraoperative or postpartum blood transfusion were recorded. Patient satisfaction with the type of anesthesia was assessed. The Apgar score at 1 and 5 min, neonatal admission to the intensive care unit, and mortality were also recorded. RESULTS: Blood loss was significantly higher in the GA than spinal group (P = 0.01). However, the number of patients who received an intraoperative or postpartum blood transfusion was statistically insignificant. Significantly more patients developed intraoperative hypotension and bradycardia in the spinal than GA group. Opioid use during the first 24 h was significantly higher in the GA than spinal group (P < 0.0001). More patients had vaso-occlusive crisis in the GA than spinal group without statistical significance (P = 0.4). There was one case of acute chest syndrome in the GA group. No significant differences were observed in postoperative nausea and/or vomiting, patient satisfaction, or hospital length of stay. Neonatal Apgar scores were significantly better in the spinal than GA group at 1 and 5 min (P = 0.006 and P = 0.009, respectively). Neonatal intensive care admission was not significantly different between the two groups, and there was no neonatal mortality. CONCLUSIONS: Spinal anesthesia may have advantages over GA in parturients with SCA undergoing Cesarean delivery.

Comparison of dexmedetomidine and dexamethasone for prevention of postoperative nausea and vomiting after laparoscopic cholecystectomy.

BACKGROUND: Postoperative nausea and vomiting (PONV) are common following laparoscopic cholecystectomy (LC). Dexamethasone has been reported to reduce PONV. However, there is insufficient evidence regarding the effect of dexmedetomidine in decreasing PONV. This study was designed to compare the effects of a single dose of dexmedetomidine to dexamethasone for reducing PONV after LC. METHODS: Eighty-six adult patients scheduled for LC were randomized to receive either single dose 1 µg/kg of dexmedetomidine (Dexmed group, N = 43) or 8 mg dexamethasone (Dexa group, N = 43) before skin incision. During the first 24 h postoperatively, the incidence and severity of PONV were assessed. Pain and sedation scores were assessed on arrival in the recovery room and early postoperatively. Analgesic and antiemetic consumption during the 24 h after surgery were calculated. Intra-operative and postoperative hemodynamics were recorded. RESULTS: Twenty-one percent of the patients in the Dexmed group developed PONV compared to 28% in the Dexa group (P = 0.6). Severity of PONV was similar between the two groups (P = 0.07). Early postoperatively, pain severity was significantly lower in the Dexmed group, but sedation scores were significantly higher. The first analgesic request was significantly delayed in the Dexmed group (P = 0.02). The total amounts of intraoperative fentanyl and postoperative tramadol administered were significantly lower in the Dexmed group. No difference in ondansetron was noted between the two groups. Mean arterial pressure and heart rate were significantly lower in the Dexmed group after administration of dexmedetomidine. No major side effects were reported. CONCLUSIONS: Dexmedetomidine reduces the incidence and severity of PONV, similar to dexamethasone. It is superior to dexamethasone in reducing postoperative pain and total analgesic consumption during the first 24 h after LC.

Behavioral and emotional effects of repeated general anesthesia in young children.

BACKGROUND: Preclinical and clinical data suggest the possibility of neurotoxicity following exposure of young children to general anesthetics with subsequent behavioral disturbances. The aim of the study was to determine the overall effect of repeated general anesthesia on behavior and emotions of young children aged 1½-5 years old, compared to healthy children. MATERIALS AND METHODS: Thirty-five children underwent repeated anesthesia and surgery were matched with the same number of healthy children who attended vaccination clinic, as a control group. Both groups were administered the child behavior checklist (CBCL) 1½-5 years and Diagnostic and Statistical Manual of Mental Disorders (DSM) oriented scale. Behavior data were collected through a semi-structured questionnaire. RESULTS: The CBCL score revealed that children with repeated anesthesia were at risk to become anxious or depressed (relative risk [RR]; 95% confidence interval [CI] = 11 [1.5-80.7]), to have sleep (RR; 95% CI = 4.5 [1.1-19.4]), and attention problems (RR; 95% CI = 8 [1.1-60.6]). There was no difference in the risk between the two groups regarding emotionally reactive, somatic complaints, withdrawn problems, aggressive behavior, internalizing or externalizing problems. On DSM scale, children with repeated anesthesia were at risk to develop anxiety problems (RR; 95% CI = 3.7 [1.1-12.0]), and attention deficit/hyperactivity problems (RR; 95% CI = 3 [1.1-8.4]). There was no difference in the risk between the two groups regarding affective, pervasive developmental and oppositional defiant problems. CONCLUSION: Young children who undergone repeated surgical procedures under general anesthesia were at risk for subsequent behavioral and emotional disturbances. Proper perioperative pain management, social support, and avoidance of unpleasant surgical experiences could minimize these untoward consequences.

Behavioral impact of sickle cell disease in young children with repeated hospitalization.

BACKGROUND: Sickle cell disease (SCD) in children with a history of repeated hospitalization is distressing for children as well as their parents leading to anxiety and has negative effects on the psychological state of children and their families. OBJECTIVE: The aim of the study was to determine the overall effect of SCD on the behavior of young children age 1½ to 5 years old who had repeated history of hospitalization, compared to a control group of healthy children attended a vaccination clinic. PATIENTS AND METHODS: Thirty-five children of age 1½ to 5 years who have SCD and repeated history of hospitalization were recruited from pediatric clinic as the study group and matched with same number of healthy children who attended vaccination clinic, as a control group. Both groups were administered the child behavior checklist (CBCL) 1½ to 5 years and diagnostic and statistical (DSM)-oriented scale. Behavior data were collected through a semi-structured questionnaire. RESULTS: CHILDREN WHO HAVE SCD HAD STATISTICALLY SIGNIFICANT BEHAVIORAL CHANGES ON CBCL COMPARED TO THE CONTROL GROUP: Anxiety/depression (65.2 vs. 55.1; P < 0.001), somatic complaint (66.7 vs. 54.4; P < 0.001) withdrawn (63.4 vs. 53.2; P < 0.001), aggressive behavior (60.4 vs. 56; P=0.04), and internalizing symptoms (64.7 vs. 51.5; P < 0.001), respectively. The DSM scale showed that children with SCD scored significantly higher in pervasive developmental disorder compared to the control group (60.9 vs. 53.9; P < 0.001) respectively. CONCLUSION: Children with SCD who had history of repeated hospitalization are at an increased risk of developing behavioral problems. Psychological counseling, social support, and proper pain management could minimize these behavioral consequences.

Electrocardiographic activity before onset of postoperative atrial fibrillation in cardiac surgery patients.

BACKGROUND: Electrocardiographic (ECG) characteristics were analyzed in postoperative cardiac surgery patients in an attempt to predict development of new-onset postoperative atrial fibrillation (AF). METHODS: Nineteen ECG characteristics were analyzed using computer-based algorithms. The parameters were retrospectively analyzed from ECG signals recorded in postoperative cardiac surgery patients while they were in the cardiovascular intensive care unit (CVICU) at our institution. ECG data from 99 patients (of whom 43 developed postoperative AF) were analyzed. A bootstrap variable selection procedure was applied to select the most important ECG parameters, and a multivariable logistic regression model was developed to classify patients who did and did not develop AF. RESULTS: Premature atrial activity (PAC) was greater in AF patients (P < 0.01). Certain heart rate variability (HRV) and turbulence parameters also differed in patients who did and did not develop AF. In contrast, P-wave morphology was similar in patients with and without AF. Receiver operating curve (ROC) analysis applied to the model produced a C-statistic of 0.904. The model thus correctly classified AF patients with more than a 90% sensitivity and a 70% specificity. CONCLUSION: Among the 19 ECG parameters analyzed, PAC activity, frequency-domain HRV, and heart rate turbulence parameters were the best discriminators for postoperative AF.

Dosing of remifentanil to prevent movement during craniotomy in the absence of neuromuscular blockade.

BACKGROUND: In neuroanesthesia practice, muscle relaxants may at times need to be avoided to facilitate intraoperative motor pathway monitoring. Our study's objective was to determine the optimal dose of remifentanil required to prevent movement after neurosurgical stimulation. METHODS: After Institutional Review Board approval and written informed consent, 132 patients undergoing elective craniotomy randomly received one of 12 remifentanil dose regimens (0.10 to 0.21 microg/kg/min). Remifentanil was started before induction with propofol and succinylcholine. Anesthesia was maintained with isoflurane (0.6% end-tidal) in air/oxygen. During the study, movement was assessed on predetermined criteria by the anesthesiology, nursing, and neurosurgical teams. Heart rate and blood pressure were recorded every 5 minutes. We assessed the relationship between movement, hypotension, bradycardia, and dose using probit analysis and logistic regression. RESULTS: Sixty-five percent of the patients moved in response to surgical stimuli [95% confidence interval (CI): 49%-79%] at a remifentanil infusion rate of 0.10 microg/kg/min, and movement decreased to 21% (95% CI: 11-35) at 0.21 microg/kg/min. The probability of movement was 50% at an infusion rate (95% CI) of 0.13 (0.10 to 0.15) microg/kg/min remifentanil and decreased to 25% at an infusion rate of 0.19 (0.17 to 0.29) microg/kg/min. The probability of hypotension and bradycardia was 50% at 0.13 (0.10 to 0.15) microg/kg/min and 0.17 (0.15 to 0.21) microg/kg/min, respectively. CONCLUSIONS: Higher doses of remifentanil lessen the risk of movement in the absence of muscle relaxants with surgical stimulation for elective craniotomy. Hypotension and bradycardia were common at higher doses. Even at the maximum dose (0.21 mcg/kg/min) there was a 20% chance of movement. Adjunctive therapy is needed to ablate movement reliably, and to counteract the hypotensive effect of remifentanil. These findings may be helpful for clinicians administering remifentanil and isoflurane during procedures, where muscle relaxants may not be desirable.

Transdermal oxygen does not improve sternal wound oxygenation in patients recovering from cardiac surgery.

BACKGROUND: Sternal wound dehiscence and infection complicate 1% of cardiac surgeries. Tissue oxygen tension (PsqO(2)) is the primary determinant of surgical wound infection risk and is often critically low in surgical incisions. We tested the hypothesis that local transdermal delivery of oxygen improves oxygenation in sternotomy wounds after cardiac surgery. Our secondary hypothesis was that supplemental inspired oxygen improves sternal wound PsqO(2). METHODS: After undergoing cardiopulmonary bypass, 30 patients randomly received (1) 2 EpiFlo oxygen generators (Ogenix, Inc., Beachwood, OH) that provided oxygen at 6 mL/h into an occlusive wound dressing or (2) identical-appearing inactive generators. PsqO(2) and temperature were measured in the wound approximately 5 mm below the skin surface. PsqO(2) and arterial oxygen (Pao(2)) were measured 1 h after intensive care unit admission (Fio(2) = 60%) and on the first and second postoperative mornings at Fio(2) of both 30% and 50% in random order. RESULTS: Data from four patients were excluded for technical reasons. Patient characteristics were similar in each group, as were type of surgery and perioperative management. Increasing Fio(2) from 30% to 50% improved Pao(2) from 99 [84-116] to 149 [128-174] mm Hg (P < 0.001, mean [95% CI]) and sternal wound PsqO(2) from 23 [16-33] to 27 [19-38] mm Hg (P < 0.001). In contrast, local oxygen delivery did not improve tissue oxygenation: 24 [14-41] vs 25 [16-41] mm Hg (P = 0.88). CONCLUSIONS: Additional inspired oxygen improved Pao(2) and sternal wound PsqO(2) after bypass and may, consequently, reduce infection risk. However, oxygen insufflated locally into an occlusive dressing did not improve wound PsqO(2) and, therefore, does not appear to be useful clinically in cardiac surgery patients to reduce sternal wound infections.

An evaluation of a full-access underbody forced-air warming system during near-normothermic, on-pump cardiac surgery.

BACKGROUND: A new underbody forced-air warming system is available for use during cardiac surgery. We tested the hypothesis combining underbody forced-air warming with standard thermal management would maintain intraoperative core temperature and reduce core temperature after-drop (largest decrease in core temperature in the 60 min after bypass) in patients undergoing near-normothermic cardiopulmonary bypass (CPB). METHODS: Patients undergoing routine, nonemergent cardiac surgery were randomly assigned to routine thermal management (fluid warming and passive insulation, n = 30) or routine management supplemented by an active underbody forced-air system (n = 30; Arizant Healthcare Model 635, Eden Prairie, MN). Core body temperature was measured by bladder catheter at 15-min intervals during the perioperative period. Comparisons were made between groups for temperature before, during, and after CPB. RESULTS: Data from four patients were excluded for cause, leaving 29 patients in the routine management group and 27 patients in the forced-air group. Initial temperatures were similar, but temperatures in the forced-air group were higher than in the routine group at the start of CPB (36.3 degrees C +/- 0.6 degrees C vs 35.7 degrees C +/- 0.7 degrees C, P = 0.002). There were no differences between groups in the lowest temperatures during CPB (forced air, 35.5 degrees C +/- 1.5 degrees C vs routine, 35.3 degrees C +/- 1.3 degrees C, P = 0.67); the end of CPB (36.7 degrees C +/- 0.4 degrees C vs 36.6 degrees C +/- 0.4 degrees C, P > 0.99); or the temperature at departure from the operating room (36.5 degrees C +/- 0.4 degrees C vs 36.2 degrees C +/- 0.5 degrees C, P = 0.36). After-drop was 0.03 degrees C +/- 0.54 degrees C in patients randomized to underbody forced-air warming and 0.21 degrees C +/- 0.51 degrees C in those assigned to routine management (P = 0.20). CONCLUSIONS: Adding an underbody forced-air warming system to the near-normothermic thermal management protocol significantly increased pre-bypass temperature; however, it had no further clinically important effect on core temperature.

Effect of dexamethasone on atrial fibrillation after cardiac surgery: prospective, randomized, double-blind, placebo-controlled trial.

OBJECTIVE: The purpose of this study was to assess the effect of preoperative dexamethasone (DEX) on the occurrence of postoperative atrial fibrillation (AF). DESIGN: Prospective, randomized, double-blind, placebo-controlled clinical trial. SETTING: Tertiary referral center. PARTICIPANTS: Seventy-eight adult patients undergoing combined valve and coronary artery bypass graft (CABG) surgery were randomized to receive either DEX or placebo. INTERVENTIONS: The DEX group received dexamethasone, 0.6 mg/kg, after induction of anesthesia, and the placebo group received an equal volume of normal saline. Interleukin (IL)-6, -8, and -10; tumor necrosis factor alpha; and endothelin (ET)-1 were measured preoperatively and on postoperative days (POD) 1, 2, and 3. Complement (C-4) and C-reactive protein (CRP) were measured preoperatively and on POD 2. Exhaled nitric oxide (NO) was measured preoperatively, 15 minutes after aortic unclamping, and 1 hour after intensive care unit admission. MEASUREMENTS AND MAIN RESULTS: No significant difference in the incidence of AF was found between the placebo (41%) and DEX groups (30%) (95% confidence interval [-11%, 34%); p = 0.31). DEX significantly reduced at least 1 postoperative level of IL-6, IL-8, IL-10, CRP, and exhaled NO. DEX did not affect ET-1 or C-4 levels. IL-10 on POD 3 was positively correlated with postoperative hospital length of stay (r = 0.30, p = 0.01). Increased levels of IL-8 and IL-10 on POD 1 were positively correlated with the intubation time (r = 0.31, p = 0.01; r = 0.30, p = 0.01, respectively). Conversely, C-4 on POD 2 was negatively correlated with the intubation time and intensive care unit length of stay (r = -0.32, p = 0.006; r = -0.30, p = 0.01, respectively). CONCLUSIONS: DEX did not affect the incidence of AF in patients undergoing combined CABG and valve surgery. However, it did modulate the release of several inflammatory and acute-phase response mediators that are associated with adverse outcomes.

Risks and outcomes of acute kidney injury requiring dialysis after cardiac transplantation.

BACKGROUND: Risk factors for postoperative acute kidney injury (AKI) are well described in nontransplantation settings. Data regarding risks and consequences of AKI after cardiac transplantation are unclear. METHODS: We analyzed 756 cardiac transplant recipients between 1993 and 2004. The primary outcome is postoperative AKI requiring dialysis therapy. Secondary outcomes are hospital mortality and postoperative morbidities, including cardiac, neurological, and serious infection. Wilcoxon rank-sum, chi-square, or Fisher exact tests were used for univariable comparison. A bootstrap-bagging procedure (1,000 repetitions) and multivariable logistic analysis with multiple imputation were used for the final model. RESULTS: AKI frequency was 5.8% (44 of 756 patients). By means of univariable analysis, preoperative risk factors for AKI were diabetes, prior cardiac surgery, intra-aortic balloon pump use, albumin level, creatinine level, clinical severity score, and cold ischemia time. Intraoperative risk factors were cardiopulmonary bypass time and transfusion requirement. By means of multivariate analysis, serum creatinine level (odds ratio [OR], 2.7; 95% confidence interval [CI], 1.6 to 4.6), serum albumin level (OR, 0.34; 95% CI, 0.21 to 0.54), insulin-requiring diabetes (OR, 3.5; 95% CI, 1.4 to 9.0), and cardiopulmonary bypass time (OR, 1.29; 95% CI, 1.02 to 1.64) were independent predictors of postoperative AKI. The overall postoperative mortality rate was 4.2%; it was 50% in patients with AKI compared with 1.4% in patients without AKI. AKI was associated with greater frequencies of cardiac, neurological, and serious infection morbidities (43.2%, 18.2%, and 54.6% versus 5.5%, 2.3%, and 7.2%, respectively; P < 0.001). CONCLUSION: AKI is associated with significant morbidity and mortality after cardiac transplantation. Predictors of AKI can be used to risk-stratify patients to ameliorate further kidney injury and offer a survival benefit.