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ABSTRACT: 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.
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.
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.
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.
Journal of the Formosan Medical Association 08/2009; 108(7):548-53. · 1.13 Impact Factor
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ABSTRACT: Resuming two lung ventilation (2LV) from one lung ventilation (OLV) has been proven to induce significant oxidative stress, mainly by superoxide release. Although total intravenous anesthesia and inhalational anesthesia are both used in thoracic surgery, different anesthetics may alter the oxidant/antioxidant balance.
Thirty patients undergoing thoracic surgery were randomly allocated to the propofol infusion (intravenous) group or isoflurane (inhalational) group after induction and placement of a double lumen endobronchial tube. Reactive oxygen species (ROS) production and total antioxidant status (TAS) were measured during OLV and 2LV manipulations. Blood samples were taken in the lateral position before OLV (T1), immediately before resuming 2LV (T2), and 5 minutes (T3) and 20 minutes (T4) after resuming 2LV, for measurement of ROS.
ROS production increased significantly at T3 and T4 in both groups but to a lesser extent in the propofol infusion group. TAS levels increased with time in the propofol group but not in the isoflurane group.
Propofol infusion, compared with isoflurane inhalation, attenuates ROS production and limits it for 20 minutes after resuming 2LV from OLV. Propofol infusion may be beneficial to patients with inadequate antioxidant capacity.
Acta Anaesthesiologica Taiwanica 01/2009; 46(4):160-5.
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ABSTRACT: 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.
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.
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.
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.
Journal of the Formosan Medical Association 06/2008; 107(6):478-84. · 1.13 Impact Factor
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ABSTRACT: The measurement of anesthetic depth is important in anesthesiology. Although heart rate variability (HRV) is profoundly affected by general anesthesia, it has not yet been commonly used in this field. One of the reasons is the lack of suitable parameters of HRV for short-term observations. In this study, we designed a time domain parameter of HRV named the similarity index. It was based on observing the trend of the distribution of instantaneous heart rates as time moved. Taking epochs of ECG data as short as 64 s can derive the index. We observed the values of this index of 30 patients when they were awake and under isoflurane anesthesia. The values had very little overlapping between the two states and the prediction probability to distinguish the two states was 0.91. We suggest that HRV, if suitably treated, can play more roles in the monitoring of anesthetic depth.
Medical & Biological Engineering 05/2008; 46(10):977-84. · 1.76 Impact Factor
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ABSTRACT: Spontaneous baroreflex sensitivity (SBR) has been suggested to be a measure of tonic parasympathetic cardiac control. The decrease of SBR during vagal inhibition was proven before. In this study, we investigated the response of SBR during vagal activation by administering intravenous atropine and phenylephrine in eight and ten healthy volunteers respectively. Atropine was given at a rate of 0.5 micro g/kg/min for 20 minutes and the infusion rate of phenylephrine was adjusted to increase the blood pressure 20 to 30 mmHg above baseline value. We found that SBR at first increased from 16.9 +/- 9.5 to 41.5 +/- 24.9 ms/mm Hg (p < 0.05) and then decreased to 8.9 +/- 6.2 ms/mm Hg (p < 0.05 compared with the peak value) after the initiation of atropine infusion. SBR also increased significantly (27.2 +/- 12.5 to 49.6 +/- 11.3 ms/mm Hg, p < 0.01) during phenylephrine infusion. The authors propose SBR as a measure of cardiac vagal effect because SBR increases under vagal activation.
Clinical Autonomic Research 07/2004; 14(3):189-93. · 1.30 Impact Factor
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ABSTRACT: Severe hypotension deteriorates renal functions and renal hemodynamics especially renal cortical blood flow. Systemic hypotension following high level spinal anesthesia may impair renal functions in spite of the blockade of renal sympathetic nerves that may help prevent vasoconstriction. Fluid loading is clinically applied for preventing hypotension but the effects on the changes of renal functions have not been studied. This study was designed to investigate the effects of fluid loading on systemic hemodynamics, renal hemodynamics and functions especially the blood distribution to renal cortex.
A rat model was used in our study. Intravenous normal saline infusion was started in both control group (5 ml/kg/h, 8 rats) and fluid loading group (15 ml/kg/h, 8 rats) 30 min before spinal anesthesia. A high level (above T4) spinal anesthesia was conducted via a preset intrathecal catheter with 0.5% hyperbaric bupivacaine. Blood pressure, heart rate and renal cortical microvascular blood flow (CMBF) were measured via a laser Doppler probe firmly contacted on renal cortex and recorded continuously after spinal anesthesia. Renal functions including glomerular filtration rates (GFR, by inulin clearance), effective renal plasma flow (ERPF, by P-aminohippurate clearance), urine flow rate (UFR) and electrolytes excretion were measured every 30 min after spinal anesthesia.
Severe hypotension was notable within 5-10 min after intrathecal anesthesia and recovered with 30 min in both groups but the difference was not significant between groups. In the control group, GFR and ERPF decreased significantly in the first 30 min by 51.9 +/- 19.8% and 44.3 +/- 13.7% respectively (P < 0.05) and recovered after 60 min. Also the deteriorations of UFR and CMBF were significantly longer (over 60 min). In fluid loading group, ERPF, UFR and CMBF could maintain throughout the experiment but only GFR was affected in the first 30 min.
Fluid administration did not prevent hypotension following high level spinal anesthesia but might have beneficial effects on renal hemodynamics especially on the renal cortical circulation and urine flow rate.
Acta anaesthesiologica Sinica 03/2003; 41(1):7-12.
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ABSTRACT: The release of a tourniquet produces reactive oxygen species (ROS), which can cause ischemia-reperfusion injury. We investigated the effects on ROS production in 22 adult ASA physical status I-II patients sedated with small-dose propofol infusion and IV midazolam undergoing elective total knee replacement under intrathecal anesthesia, allocated randomly to one of two groups. In the Propofol group, sedation was performed with propofol 0.2 mg/kg followed by infusion at a rate of 2 mg. kg(-1). h(-1). In the Control group, IV midazolam 5 mg was given. ROS production was measured by lucigenin chemiluminescence analysis. Blood samples were obtained from the radial artery after spinal anesthesia, 1 min before release of the tourniquet and 5 and 20 min after reperfusion. The ischemic time was approximately 70 min. ROS production decreased nonsignificantly before reperfusion in both groups but increased significantly 5 and 20 min after reperfusion in the Midazolam group. In the Propofol group, no significant increase of ROS production was found. We conclude that small-dose propofol infusion attenuates ROS production in tourniquet-induced ischemia-reperfusion injury. IMPLICATIONS: Small-dose propofol sedation, compared with IV midazolam, attenuates free radical production after release of the tourniquet during total knee replacement under spinal anesthesia.
Anesthesia & Analgesia 07/2002; 94(6):1617-20, table of contents. · 3.29 Impact Factor
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ABSTRACT: Spontaneous baroreflex sensitivity, high-frequency gain, (0.15–0.35 Hz), and mid-frequency gain (0.07–0.14 Hz) are noninvasive measures of cardiac baroreflex function derived by spontaneous sequence and cross-spectral analysis. To demonstrate the difference between these baroreflex estimates, 14 patients received etomidate (0.3 mg/kg bolus and 0.9 mg/kg/h infusion), lidocaine (60 mg), and vecuronium (0.1 mg/kg) by intravenous injection. The authors found that spontaneous baroreflex sensitivity and high-frequency gain were decreased (p<0.05) after etomidate anesthesia, whereas mid-frequency gain was maintained. Spontaneous baroreflex sensitivity, high-frequency gain, and mid-frequency gain, although compared simultaneously, did not change in a parallel manner. In another 5 patients, who received normal saline only, measures were unchanged. The authors conclude that spontaneous baroreflex sensitivity, high-frequency gain, and mid-frequency gain are not interchangeable. Experimental results on baroreflex control depend on the parameter selected.
Clinical Autonomic Research 05/2000; 10(3):117-121. · 1.30 Impact Factor
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ABSTRACT: 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.
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%.
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.
Clinical Journal of Pain 19(1):55-8. · 2.81 Impact Factor
