Tak-Yu Lee

Effect of P‐6 acupressure on prevention of nausea and vomiting after epidural morphine for post‐Cesarean section pain relief

Background: Nausea and vomiting are important side effects following administration of epidural morphine for post‐Cesarean section pain relief. Stimulation of the P‐6 (Neiguan) acupoint is a traditional Chinese acupuncture modality used for antiemetic purpose; it has been found to be effective. The aim of this study was to evaluate the antiemetic effect of P‐6 acupressure in parturients given epidural morphine for post‐Cesarean section pain relief.

Perioperative plasma concentrations of tumor necrosis factor-alpha and interleukin-6 in infected patients.

OBJECTIVE To characterize the sequential plasma concentrations of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) and their relationship with the clinical outcome in patients with intra-abdominal infection who underwent surgical intervention. DESIGN A prospective, comparative study. SETTING Surgical intensive care unit of a university hospital. PATIENTS Fifteen patients with surgically proved intra-abdominal infection were included as the infected group. The comparative noninfected group consisted of ten patients who underwent major abdominal surgery without infection. INTERVENTIONS Blood samples were obtained from the indwelling arterial catheter before induction of general anesthesia, and 1, 1.5, 2, 3, 4, 6, and 24 hrs after skin incision. MEASUREMENTS AND MAIN RESULTS Plasma cytokine concentrations were measured using radioimmunoassay. The hemodynamic and physiologic parameters were recorded for comparison with cytokine concentrations. In the noninfected group, the TNF-alpha concentration was very low throughout the observation period, and the IL-6 concentration increased 4 hrs after skin incision. The infected group had significantly higher TNF-alpha and IL-6 concentrations than the noninfected group. The TNF-alpha concentration increased from 129.2 +/- 46.4 to 1196.0 +/- 445.8 pg/mL and the IL-6 concentration increased from 54.2 +/- 24.3 to 560.3 +/- 187.5 pg/mL 2 hrs after skin incision in the infected group. The postoperative APACHE II score correlated significantly with both peak IL-6 (r2=.39) and peak TNF-alpha (r2=.32) concentrations. CONCLUSIONS Both TNF-alpha and IL-6 concentrations increased significantly after surgical intervention in patients with intra-abdominal infection. The pulse increase in TNF-alpha concentration and the persistent increase in IL-6 concentration were related to the poor postoperative clinical condition in infected patients.

Effect of Oral Clonidine Premedication on Perioperative Hemodynamic Response and Postoperative Analgesic Requirement for Patients Undergoing Laparoscopic Cholecystectomy

BACKGROUND To investigate the clinical efficacy of oral clonidine premedication in anesthesia and analgesia in patients undergoing laparoscopic cholecystectomy (LC). METHODS One hundred and ten patients, scheduled for elective laparoscopic cholecystectomy, were recruited for the prospective, randomized, single-blind, comparative study. They were randomly allotted to either of the placebo or clonidine group. Patients of the placebo group (n = 65) were premedicated with oral antacid (alugel hydroxide 300 mg), while those in the clonidine group (n = 45) were premedicated with oral clonidine 150 micrograms prior to anesthesia. The premedication was given 60 to 90 min before the anticipated time of induction of anesthesia. Normocapnia was maintained throughout the perioperative period. Mass spectrometer was used to assess the inspired and expiratory concentrations of isoflurane, the anesthetic used for maintenance of anesthesia. Postoperative pain intensity, sedation scores, adverse events, time to the first dose of postoperative analgesic and cumulative analgesic requirement in 24 hours were recorded. Data were expressed as mean +/- SD. RESULTS Patients in the clonidine group displayed greater hemodynamic stability perioperatively and the isoflurane requirement was also reduced (30% less). The postoperative analgesic requirement was less (1.5 +/- 1.3 vs. 2.2 +/- 1.3 dose, P < 0.05) and the time for the first dose of analgesic was prolonged (411 +/- 565 vs. 264 +/- 441 min) in comparison with the placebo group but no statistic difference was found. CONCLUSIONS Oral clonidine premedication helped to provide perioperative hemodynamic stability, spared the use of isoflurane and reduced the requirement of postoperative analgesia so as to smoother the way to recovery in patients undergoing LC.

Involvement of coerulospinal noradrenergic pathway in fentanyl-induced muscular rigidity in rats

Unilateral, site-specific microinjection of fentanyl (2.5 micrograms/50 nl) into the locus coeruleus (LC) in Sprague-Dawley rats anesthetized with ketamine evoked a significant increase in the electromyographic activity recorded from both caudal lateral extensor and gastrocnemius muscles. This correlate of opiate-induced muscular rigidity was appreciably antagonized by a pretreatment with the specific alpha 1-adrenoceptor blocker, prazosin (250 micrograms/kg, i.v.). On the other hand, an equimolar dose (0.65 mumol/kg) of the specific alpha 2-adrenoceptor blocker, yohimbine (0.23 mg/kg, i.v.) failed to prevent the occurrence of fentanyl-induced EMG activation. We suggest that the coerulospinal noradrenergic pathway may be directly involved in the elicitation of muscular rigidity by fentanyl, possibly via alpha 1-adrenoceptors in the spinal cord.

Involvement of locus coeruleus and noradrenergic neurotransmission in fentanyl-induced muscular rigidity in the rat

Whereas muscular rigidity is a well-known side effect that is associated with high-dose fentanyl anesthesia, a paucity of information exists with regard to its underlying mechanism(s). We investigated in this study the possible engagement of locus coeruleus of the pons in this phenomenon, using male Sprague-Dawley rats anesthetized with ketamine. Under proper control of respiration, body temperature and end-tidal CO2, intravenous administration of fentanyl (50 or 100 micrograms/kg) consistently promoted an increase in electromyographic activity recorded from the gastrocnemius and abdominal rectus muscles. Such an induced muscular rigidity by the narcotic agent was significantly antagonized or even reduced by prior electrolytic lesions of the locus coeruleus or pretreatment with the alpha-adrenoceptor blocker, prazosin. Microinjection of fentanyl (2.5 micrograms/50 nl) directly into this pontine nucleus, on the other hand, elicited discernible electromyographic excitation. It is speculated that the induction of muscular rigidity by fentanyl may involve the coerulospinal noradrenergic fibers to the spinal motoneurons.

EFFECTS OF ESTROGEN ON AUTOTOMY IN NORMAL AND OVARIECTOMIZED RATS

Gonadal hormones may modulate analgesia responses induced by acute stress in humans and rats. To evaluate the effects of gonadal hormones in modifying neuropathic pain, we measured autotomy changes following sciatic nerve resection in ovariectomized rats and in the presence of estrogen replacement. Two groups of female rats were subjected to ovariectomy and sham surgery. Each group was then divided into two subgroups receiving subcutaneously sesame oil with or without estradiol benzoate (5 μg/day/rat). All rats then underwent sciatic nerve resection in one hindlimb. Degree of self-mutilation was measured daily for 8 weeks. Estradiol treatment resulted in significantly lower autotomy scores in ovariectomized rats (3.6 ± 0.6 vs. 5.5 ± 0.3, p < 0.01) and in sham-operated rats (3.4 ± 0.7 vs. 5.1 ± 0.4, p < 0.05). The results of this study indicate that estrogen can modify the autotomy behavior, an indicator of neuropathic pain, in rats after nerve injury.

The optimal effective concentration of lidocaine to reduce pain on injection of propofol

STUDY OBJECTIVE To determine the optimal concentration of lidocaine that reduces pain on injection of a propofol-lidocaine mixture. DESIGN Prospective, randomized, double-blinded, clinical investigation. SETTING Medical center, university teaching hospital. PATIENTS 240 ASA physical status I and II female outpatients, aged 21 to 65 years, undergoing dilation and curettage with propofol for anesthesia induction. INTERVENTIONS Patients were randomized to one of four groups in double-blinded fashion. In Group A (control), patients were given propofol containing normal saline; in Group B, Group C, and Group D, patients received propofol containing 0.05% lidocaine (Group B), propofol containing 0.1% lidocaine (Group C), and propofol containing 0.2% lidocaine (Group D) for induction. MEASUREMENTS AND MAIN RESULTS The incidence of pain on injection of propofol was significantly decreased in Group C and Group D (8.3% and 10.0%, respectively) in comparison to the control group (91.7%) (p < 0.001). Although the result in Group B (76.7%) was better than that in the control group, the difference was not statistically significant. No significant difference was seen between Group C and Group D. CONCLUSIONS The optimal effective concentration of lidocaine, which decreased the incidence of pain caused by propofol injection, was 0.1% in the currently studied population.

Inadvertent knotting of a thoracic epidural catheter.

We report a case of corrosive injury of upper gastrointestinal and respiratory tracts scheduled for feeding jejunostomy under thoracic epidural anesthesia. An epidural catheter was inserted at the T8–T9 intervertebral space and threaded 7 cm beyond the tip of the Tuohy needle in a rostral direction. Resistance was noticed during attempts to inject the local anesthetic. As resistance could not be relieved by changing the position of the patient, kinking of the epidural catheter was suspected. Following informing the patient of the associated risks, the catheter was retrieved successfully by gentle and steady pulling. A tight double‐knot of catheter was found. No neurological sequelae to the procedure were noticed.

Participation of Noradrenergic Neurotransmission in the Enhancement of Baroreceptor Reflex Response by Substance P at the Nucleus Tractus Solitarii of the Rat: A Reverse Microdialysis Study

Abstract: We applied reverse microdialysis and HPLC analysis to evaluate the participation of noradrenergic neurotransmission in modulation of the baroreceptor reflex response by substance P at the nucleus tractus solitarii in Sprague‐Dawley rats anesthetized with pentobarbital sodium (50 mg/kg, i.p., with 20 mg/kg/h.i.v. supplement). Continuous infusion of substance P (600 µM) at 1 µl/min into the nucleus tractus solitarii through a stereo‐taxically positioned microdialysis probe (active exchange length, 180–200 µm; diameter, 220 µm) for 1 h elicited an enhancement of the baroreceptor reflex response. This facilitatory effect correlated positively, during the 60‐min infusion period, with the time course of increase in the extracellular concentration of substance P and noradrenaline in the nucleus tractus solitarii. Experimentally elevating the concentration of noradrenaline at this medullary nucleus also augmented the baroreceptor reflex sensitivity. On the other hand, depletion of the noradrenergic fibers and nerve terminals at the nucleus tractus solitarii with DSP4 diminished the enhancement of baroreceptor reflex response and the corresponding elevation in extracellular concentration of noradrenaline by substance P. Microinfusion of noradrenaline into the nucleus tractus solitarii in DSP4‐treated animals, however, potentiated the baroreceptor reflex response. These results suggest that the enhancement of baroreceptor reflex response by substance P may involve an increase in the concentration of noradrenaline at the nucleus tractus solitarii via a presynaptic mechanism.

Development and validation of the questionnaire of satisfaction with perioperative anesthetic care for general and regional anesthesia in Taiwanese patients.

BACKGROUND To fulfill the increasing demand of service quality improvement in recent years, it is imperative to develop a proper instrument to evaluate patient satisfaction with perioperative anesthetic care for many institutes in Taiwan. METHODS We used a six-factor 32-item pilot questionnaire developed in our previous study as our starting point in this study. Exploratory factor analysis of the pilot questionnaire for factor structure generation was performed in general anesthesia patients (group 1, n = 320) and resulted in the generation of the Patient Satisfaction with Perioperative Anesthetic Care questionnaire (PSPACq). Confirmatory factor analysis of the PSPACq in general anesthesia (group 2, n = 565) and regional anesthesia (group 3, n = 225) patients was performed for validation and cross-validation of the PSPACq model, respectively. The confounding variables and the patient loyalty effects on PSPACq scores were analyzed to evaluate the nomological validity of the PSPACq. RESULT Exploratory factor analysis of the pilot questionnaire in group 1 resulted in the development of the PSPACq (a seven-factor 30-item model). The standardized coefficients and indexes for the assessment of fit of the PSPACq model in group 2 (validation) and group 3 (cross-validation) patients revealed a well-fitting model. The results of the loyalty scores and confounding variables support the nomological validity of the PSPACq. CONCLUSIONS A valid and reliable questionnaire (PSPACq) with Taiwanese culture characteristics was developed and is suitable for testing of patient satisfaction with perioperative anesthesia care for patients receiving general or regional anesthesia for their surgery.