New 6% hydroxyethyl starch 130/0.4 does not increase blood loss during major abdominal surgery - a randomized, controlled trial.

BACKGROUND/PURPOSE: Ideal fluid management during surgery still poses a clinical dilemma gauging the benefits and adverse effects. This randomized controlled trial compared the tissue perfusion and coagulation profiles under clinically equivalent hydroxyethyl starch (HES 130/0.4) and lactated Ringer's solution (LR). METHODS: Eighty-four patients undergoing major abdominal surgery were randomized to receive either HES or LR. Tissue perfusion parameters using heart rate, arterial blood pressure, central venous pressure, cardiac index, stroke volume index, and central venous oxygen saturation were measured at T0 (baseline), T1 (start of surgery), T2 (1 hour after start of surgery), and T3 (end of surgery). Coagulation parameters using thrombelastography (TEG) were measured at T0 (baseline), T4 (after 15 mL/kg fluid transfused), and T5 (24 hours after baseline). RESULTS: The total amount of fluid administrated was 1547.9 ± 424.0 mL in HES group and 2303.1 ± 1033.7 mL in LR group (p < 0.001). The parameters of tissue perfusion and TEG did not differ significantly between groups at any time point except for a transient decrease in clot kinetic and clot strength at T4 for HES group. There was no significant difference in blood loss and consumption of blood products between the two fluids. CONCLUSION: HES 130/0.4 is a more efficient intravascular volume expander to maintain tissue perfusion than conventional crystalloid. Transient hypocoagulability induced by HES 130/0.4 does not warrant excessive blood loss and blood transfusion.

Polymorphism of µ-Opioid Receptor Gene (OPRM1:c.118A>G) Might Not Protect against or Enhance Morphine-Induced Nausea or Vomiting.

A cohort, double blind, and randomized study was conducted to investigate the effect of a single nucleotide polymorphism of the µ-opioid receptor at nucleotide position 118 (OPRM1:c.118A>G) on the association with the most common side effects (nausea or vomiting) induced by intravenous patient control analgesia (IVPCA) with morphine, including incidence and severity analysis. A total of 129 Taiwanese women undergoing gynecology surgery received IVPCA with pure morphine for postoperative pain relief. Blood samples were collected and sequenced with high resolution melting analysis to detect three different genotypes of OPRM1 (AA, AG, and GG). All candidates 24 h postoperatively will be interviewed to record the clinical phenotype with subjective complaints and objective observations. The genotyping after laboratory analysis showed that 56 women (43.4%) were AA, 57 (44.2%) were AG, and 16 (12.4%) were GG. The distribution of genotype did not violate Hardy-Weinberg equilibrium test. There was no significant difference neither between the severity and incidence of IVPCA morphine-induced side effects and genotype nor between the association between morphine consumption versus genotype. However, there was significant difference of the relation between morphine consumption and the severity and incidence of IVPCA morphine-induced nausea and vomiting. The genetic analysis for the severity and incidence of IVPCA morphine-induced nausea or vomiting showed no association between phenotype and genotype. It might imply that OPRM1:c.118A>G does not protect against IVPCA morphine-induced nausea or vomiting.

Sex differences in conscious sedation during upper gastrointestinal panendoscopic examination.

BACKGROUND/PURPOSE: Sex differences in response to noxious stimuli or analgesia have been demonstrated. We investigated sex differences in conscious sedation during upper gastrointestinal panendoscopic examination with regard to drug dose and entropy scores. METHODS: We investigated sex differences in 30 men and 30 women who were undergoing conscious sedation during upper gastrointestinal panendoscopic examination. The drug mixture was prepared as 5 mg midazolam plus 1 mg alfentanil diluted with normal saline to a volume of 10 mL. An initial injection of 4 mL was followed by an additional 1 mL every 1 minute, until the modified Observer Assessment of Alertness and Sedation (OAAS) rating scale was ≤ 3 when the panendoscope was inserted. Further injection was allowed thereafter. Entropy values, including state entropy (SE) and response entropy (RE), were monitored from baseline to full recovery. RESULTS: The volume of mixture needed to achieve an OAAS score of ≤ 3 was significantly lower in men than in women (4.4 ± 0.7 mL vs. 4.8 ± 0.8 mL, p = 0.034). The initial drug demand was not significantly influenced by age, body weight, or body height. The RE and SE values at the time of panendoscope insertion were not significantly different between men and women. The total volume for men was also significantly lower than that for women (5.7 ± 1.1 mL vs. 6.5 ± 1.4 mL, p < 0.01). The lowest RE and SE values during the procedure were not significantly different between men and women. CONCLUSION: Women need more analgesic agents than men during panendoscopic examination. There was no significant difference between men and women with regard to anesthetic depth and response to noxious stimuli, as revealed by similar SE and RE values.

Patient -controlled epidural ropivacaine as a post-Cesarean analgesia: a comparison with epidural morphine.

OBJECTIVE: Conventional, intermittent, epidural morphine is widely applied as a post-Cesarean delivery analgesia. We compared the analgesic efficacy, motor weakness, and side effects of administering a patient-controlled epidural analgesia (PCEA) of pure ropivacaine versus the intermittent administration of epidural morphine after Cesarean delivery. MATERIALS AND METHODS: This randomized, double-blind study included 120 full-term parturients who underwent elective Cesarean delivery and received either PCEA with pure ropivacaine or an intermittent bolus epidural of 2 mg/10 mL morphine in normal saline twice per day. The efficacy of pain relief, post-Cesarean side effects, motor blockades, time to first ambulation, and global satisfaction scores were evaluated. RESULTS: Pain scores were recorded at the four evaluation times (2, 12, 24, and 48 hours post-Cesarean delivery), and the time to first ambulation did not statistically differ between the two groups. Patients in the ropivacaine group experienced more motor weakness at 2 and 12 hours, fewer side effects, and higher global satisfaction scores than those in the morphine group (p < 0.05). CONCLUSION: The analgesic efficacy after cesarean delivery was almost equivalent between two groups. PCEA with pure ropivacaine induced significant motor blockade during the first 12 hours, but without delaying the time to first ambulation. Patients in the ropivacaine group reported higher patient satisfaction scores due to the significant reduction of annoying side effects, such as pruritus, nausea, vomiting, and urinary retention.

Combination of low-dose nalbuphine and morphine in patient-controlled analgesia decreases incidence of opioid-related side effects.

BACKGROUND/PURPOSE: The addition of ultra-low-dose naloxone to patient-controlled analgesia (PCA) with morphine reduces opioid-related side effects. Nalbuphine, a mixed opioid agonist-antagonist, may be able to attenuate opioid-related side effects. The goal of the present study was to investigate the effect of combined low-dose nalbuphine and morphine in PCA for postoperative pain control after gynecological surgery. METHODS: This randomized, double-blind, controlled study enrolled 174 female patients who were undergoing total abdominal hysterectomy, myomectomy, or ovarian tumor excision. In the control group, the PCA formula was 1 mg/mL pure morphine. In the study group, the PCA formula was 1 mg/mL morphine and 10 microg/mL nalbuphine (1:100). Numerical rating score, PCA requirement, nausea, vomiting, use of antiemetics, pruritus, use of antipruritics, and opioid-related adverse events were investigated at 1, 2, 4, and 24 hours postoperatively. RESULTS: One hundred and sixty-nine patients completed the study: 86 in the control group and 83 in the study group. The incidence of nausea was lower in the study group (41%) than in the control group (65%). The incidence of vomiting, use of antiemetics, pruritus, and use of antipruritics did not differ between the two groups. The numerical rating pain score and PCA requirements were not significantly different between the two groups. CONCLUSION: Combination of low-dose nalbuphine and morphine in PCA decreases the incidence of opioid-related nausea, without affecting the analgesia and PCA requirement. This novel combination can improve the quality of PCA used for postoperative pain control after gynecological surgery.

Propofol attenuates the decrease of dynamic compliance and water content in the lung by decreasing oxidative radicals released from the reperfused liver.

BACKGROUND: Remote pulmonary injuries after hepatic reperfusion are frequently caused by reactive oxygen species (ROS)-induced damage. The choice of anesthetics may affect the balance between oxidants and antioxidants, and propofol, a commonly used anesthetic, has an antioxidant effect. In this study, we developed a model to study pulmonary function with hepatic ischemia/reperfusion (I/R) manipulation, with the aim of defining remote pulmonary dysfunction after hepatic reperfusion and determining if propofol affects this dysfunction by altering ROS production from the liver or lungs. METHODS: Adult male rats weighing 160-250 g were randomly divided into four groups according to the type of surgery (sham or I/R) and the anesthetic administered (pentobarbital or propofol). To induce I/R, the portal vein and hepatic artery to the left and medial lobes of the liver were clamped. All of the measurements were done after 5 h of reperfusion, after 45 min of ischemia. Pulmonary function after hepatic I/R was determined by dynamic compliance, resistance and wet-to-dry ratio, and by histopathology. Hepato-cellular injuries were confirmed by alanine aminotransferase, whereas ROS production was measured from the inferior vena cava, jugular vein, and carotid artery. Products of lipid peroxidation, thiobarbiturate acid reactive substances and malondialdehyde, were measured in lung and hepatic tissues. RESULTS: Remote lung injury after hepatic I/R was shown by a significant decrease of Cdyn, and increases in resistance and the wet-to-dry ratio. ROS production was significantly increased and was highest in samples from the inferior vena cava. Thiobarbiturate acid reactive substances and malondialdehyde in the liver and serum alanine aminotransferase were significantly increased only in the I/R+pentobarbital group. All of the changes were significantly attenuated in the I/R+ propofol group (P=0.05). With propofol infusion, there was decreased ROS production from the reperfused liver, with less hepato-cellular injury, followed by well-maintained pulmonary function. CONCLUSION: Remote pulmonary dysfunction and reperfusion injury in the liver were demonstrated in our rat model, as well as massive ROS production and lipid peroxidation. Propofol infusion attenuated remote pulmonary injury by lessening oxidative injury from the reperfused liver.

Effect of combining ultralow-dose naloxone with morphine in intravenous patient-controlled analgesia: the cut-off ratio of naloxone to morphine for antiemesis after gynecologic surgery.

BACKGROUND/PURPOSE: Admixing an ultralow dose of naloxone with intravenous morphine patient-controlled analgesia (PCA) has been shown to decrease postoperative nausea. However, the cut-off ratio of the naloxone-morphine admixture for antiemetic effects has not been investigated. The purpose of this study was to investigate the cut-off ratio of naloxone-morphine admixture in PCA for antiemesis after gynecologic surgery. METHODS: This double-blind study enrolled 120 female patients who were scheduled for gynecologic surgery under general anesthesia. Patients were randomly allocated to one of three groups (n = 40 for each group). The concentration of naloxone and morphine respectively was 0 microg/mL and 1 mg/mL in group 1, 0.1 microg/mL and 1 mg/mL in group 2 (1:10,000), and 1 microg/mL and 1 mg/mL in group 3 (1:1000). Morphine consumption, verbal rating score of wound pain at rest and with exertion, and morphine-related side effects were investigated at 1, 2, 4 and 24 hours postoperatively. RESULTS: A total of 112 patients completed the study (37 in group 1, 36 in group 2, 39 in group 3). The incidence of nausea during the postoperative 4-24 hours was significantly lower in group 3 than in group 1 (23.1% vs. 56.8%, p < 0.05). Furthermore, the overall incidence of severe nausea was significantly lower in group 3 than in group 1 (2.6% vs. 24.3%, p < 0.05) as was the rescue antiemetic requirements (5.1% vs. 24.3%, p < 0.05). However, there were no significant differences between groups 2 and 1. The pain scores (at rest and with exertion) and 24-hour morphine consumption were not significantly different among the three groups. CONCLUSION: The antiemetic efficacy of ultralow-dose naloxone combined with PCA morphine is limited by a cut-off ratio of naloxone to morphine of 1:10,000.

Oxidative stress during 1-lung ventilation.

OBJECTIVES: Resuming 2-lung ventilation from 1-lung ventilation might induce a re-expansion and reoxygenation effect. The oxidative stress during 1-lung ventilation/2-lung ventilation has not been studied, although severe complications, such as re-expansion pulmonary edema, were reported. Reactive oxygen species production and total antioxidant status assay levels were measured in this study during 1-lung ventilation/2-lung ventilation. The effects on extravascular lung water, cardiac output, and intrathoracic blood volume were also studied by using the Pulsion PiCCO system. METHODS: Twenty patients undergoing 1-lung ventilation/2-lung ventilation (>60 minutes) for video-assisted thoracoscopic surgery with minimal lung injuries were included in this study. Reactive oxygen species production was measured by means of lucigenin (detecting superoxide mainly) and luminol (detecting H2O2 and HOCl mainly) chemiluminescence. Reactive oxygen species production, total antioxidant status assay (by using the Randox TAS kit), extravascular lung water, cardiac output, and intrathoracic blood volume values were measured before 1-lung ventilation (T1), before resuming 2-lung ventilation (T2), 5 minutes after 2-lung ventilation (T3), and 30 minutes after 2-lung ventilation (T4). RESULTS: One-lung ventilation time was 118 +/- 33 minutes. Lucigenin chemiluminescence (but not luminol chemiluminescence) increased significantly at T3 and T4. Total antioxidant status decreased nonsignificantly. Extravascular lung water, intrathoracic blood volume, and permeability index values changed nonsignificantly after 2-lung ventilation. Cardiac output increased significantly at T4, and there is a negative correlation between cardiac output and extravascular lung water (r = -0.431, P < .005). CONCLUSIONS: Resuming 2-lung ventilation induces a massive superoxide production. Comparable extravascular lung water and intrathoracic blood volume and a nonsignificant decrease of total antioxidant status indicate adequate antioxidant capacity to counteract it. Severe oxidative injuries after 1-lung ventilation/2-lung ventilation should be considered in patients without adequate antioxidative capacity, such as those with cancer and trauma.

The optimal injection time of alfentanil for blunting circulatory responses to tracheal intubation.

BACKGROUND: The aim of this study is to investigate the optimal injection time of alfentanil during induction of anesthesia to blunt the circulatory responses induced by laryngoscopy and tracheal intubation. METHODS: Seventy-five patients of ASA class I or II were randomly assigned to five groups. Group I was the placebo group in which the patients received normal saline 2 ml just before induction. Patients in groups II, III, IV and V received alfentanil 10 microg/kg at 5, 3, 1 and 0.5 min before intubation respectively. Anesthesia was maintained with 1.5% isoflurane and nitrous oxide in 50% oxygen (2:2 L/min). The patients' heart rate and blood pressure before and after intubation were documented and compared. The occurrence of adverse effects was also recorded. RESULTS: Patients' demographic data, baseline hemodynamic profile and the laryngoscopic time did not differ among the five groups. The patients in groups II, III and IV showed decreased heart rate compared with group I within 3 min after intubation. The patients in group V like those in group I did not show a reduction in heart rate 1 min after intubation. The patients in groups II, III, IV and V all showed reduced systolic blood pressure and rate-pressure product (RPP) 2 min after intubation. The occurrence of hypotension and bradycardia was not different among the five groups; hypertension and high RPP were less in groups II, III and IV as compared with group I. Ninety-three percent patients in group II and group III suffered from dizziness after alfentanil administration. One patient in group II had nausea and another one patient displayed hypoxemia after alfentanil administration. CONCLUSIONS: Considering equal effectiveness and fewer side effects, one minute before intubation is the optimal injection time of alfentanil to blunt the circulatory responses induced by laryngoscopy and tracheal intubation.

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.

Intraoperative TEE monitoring on pulmonary thromboembolectomy--a case report.

We present a successful thromboembolectomy under intraoperative transesophageal echocardiography (TEE) monitoring on a woman with massive pulmonary embolism (PE). Sudden onset of dyspnea happened 7 days after lumbar spine surgery and ventilation/perfusion scan and angiography performed right away were suggestive of PE. Operation was performed 17 days later after invalid anticoagulant treatments and unavailing catheter fragmentation. Intraoperative TEE showed massive emboli in the main and right pulmonary arteries (MPA and RPA) and dilated right atrium (RA) with deviated intraatrial septum. Removal of the emboli was performed smoothly under TEE monitoring. The dilation of RA, right ventricle (RV) and PA were resolved soon after thromboembolectomy. The patient was extubated the next day with obvious improvement of clinical symptoms and discharged two weeks later without neurological sequale. We conclude that TEE can be an excellent tool not only for early diagnosing PE in high risk patients but also for intraoperative monitoring on removing emboli and managing cardiac functions.

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.