Chia Chih Tseng

Human opioid receptor A118G polymorphism affects intravenous patient-controlled analgesia morphine consumption after total abdominal hysterectomy.

Background:Animal and human studies indicate that genetics may contribute to the variability of morphine efficacy. A recent report suggested that cancer patients homozygous for the 118G allele caused by the single nucleotide polymorphism at nucleotide position 118 in the &mgr;-opioid receptor gene require higher doses of morphine to relieve pain. The purpose of the current study was to investigate whether this polymorphism contributes to the variability of morphine efficacy in women who undergo abdominal total hysterectomy. Methods:After informed consent was obtained, 80 female patients (American Society of Anesthesiologist physical status I or II) scheduled to undergo elective total hysterectomy surgery were enrolled in this study. All patients received general anesthesia and were screened for A118G polymorphism by blood sample. Intravenous morphine patient-controlled analgesia was provided postoperatively for satisfactory analgesia. The authors recorded the morphine consumption doses and demand times. Pain at rest and side effects were measured with rating scales. Results:Forty-three women were A118 homozygous, 19 were heterozygous, and 18 were G118 homozygous. Patients homozygous for G118 required more morphine doses (33 ± 10 mg) to achieve adequate pain relief compared with patients homozygous for A118 (27 ± 10 mg) in the first 24 h (P = 0.02). However, there was no statistically significant difference for morphine consumption at 48 h. Conclusion:Genetic variation of the &mgr;-opioid receptor may contribute to interindividual differences in postoperative morphine consumption. In the future, identifying single nucleotide polymorphisms of patients may provide information to modulate the analgesic dosage of opioid for better pain control.

Decrease of anesthetics activity by electroacupuncture on Jen-Chung point in rabbits

The effect of acupuncture at life-saving point on the central nervous depressive action of anesthetics was investigated in rabbits. Stimulation with electroacupuncture (EA) inserted in Jen-Chung point, which is located at the mid-point on the upper lip, decreased the sleeping time induced by pentobarbital or propofol. However, this action of acupuncture was not modified by naloxone at the doses sufficient to block opiate receptors. Plasma beta-endorphin detected by radioimmunoassay was also not markedly changed in rabbits which received similar electrostimulation. Moreover, pretreatment with para-chlorophenylalanine at a dose sufficient to deplete endogenous 5-hydroxytryptamine (5-HT) failed to influence the action of EA. Mediation of endogenous opioids and/or 5-HT in this action of EA was then ruled out. Prazosin reversed the sleeping time decreasing action of acupuncture in a dose-dependent manner. Also, the action of acupuncture was eliminated in rabbits which received intracerebroventricular injection of guanethidine at a dose which could block noradrenergic nerve terminals. It is suggested that stimulation of Jen-Chung point through EA can activate noradrenergic neurotransmission in the brain, which in turn reduces the central nervous depressive activity of anesthetics.

Intrathecal coelectrotransfer of a tetracycline‐inducible, three‐plasmid‐based system to achieve tightly regulated antinociceptive gene therapy for mononeuropathic rats

For optimal use of antinociceptive gene therapy, it may be important to have extrinsic control of the expression of the transfected gene. To achieve this goal, we used a tetracycline‐inducible system (Tet‐On) composed of three plasmids coding for beta‐endorphin, the tetracycline transcriptional activator rtTA, and the silencer tTS. The regulation of beta‐endorphin expression was first assessed in cultures of dorsal root ganglion neurons. The three plasmids were then electrotransfected into the spinal cord of mononeuropathic rats and the analgesic potential of this therapy in vivo was evaluated by thermal‐withdrawal latency and the mechanical‐withdrawal threshold. Intraperitoneal injections of doxycycline were made to evaluate the possibility of exogenous upregulation of transfected beta‐endorphin gene expression in vivo. The levels of beta‐endorphin were analyzed by intrathecal microdialysis and radioimmunoassay. We found that, after doxycycline administration, the expression of beta‐endorphin was rapid, stable, and tightly regulated (low background and high induction level) both in vitro and in vivo. The beta‐endorphin protein was secreted into cerebrospinal fluid at a peak level of 53 pmol/L in dialysate, which was sufficient to inhibit neuropathic pain. In conclusion, tightly controlled expression of beta‐endorphin can be obtained following intrathecal electrotransfer of a tetracycline‐inducible, three‐plasmid‐based system, and doxycycline‐dependent beta‐endorphin protein expression in this system alleviates sciatic nerve constriction‐induced limb pain. Copyright

The clinical use of small-dose tetracaine spinal anesthesia for transurethral prostatectomy

In a double-blinded study, we compared conventional dose tetracaine (8 mg), small-dose tetracaine (4 mg) with added fentanyl and epinephrine, and small-dose tetracaine (4 mg) with added fentanyl subarachnoid anesthesia. Forty-five patients scheduled for transurethral resection of prostate (TURP) under subarachnoid anesthesia were randomly assigned to Group 1 (8 mg hyperbaric tetracaine), Group 2 (4 mg hyperbaric tetracaine, 10 &mgr;g fen-tanyl, and 0.2 mg epinephrine), and Group 3 (4 mg hyperbaric tetracaine, 10 &mgr;g fentanyl, and 0.2 mL saline). Evaluations were performed after spinal anesthesia. Subarachnoid block was successful in all patients except one in Group 1, who required general anesthesia by mask. The median peak sensory levels 10 min after the induction of spinal anesthesia in Group 1 was T8, which was significantly higher than Group 2 and Group 3 (P < 0.05). The time of sensory and motor recovery in Group 3 was less than in Groups 1 and 2 (P < 0.05). Hypotension was observed in four patients in Group 1 and none in Groups 2 and 3. We conclude that small-dose 4-mg hyperbaric tetracaine plus 10 &mgr;g fentanyl might provide adequate anesthesia and fewer side effects for TURP when compared with the conventional (8 mg) dose.

Acute Coronary Syndrome in Cisatracurium-induced Anaphylactic Shock: Kounis Syndrome

In this case report, we describe a 70-year-old male patient who sustained Kounis syndrome induced by cisatracurium administration immediately following induction of general anesthesia. Acute coronary syndrome combined with anaphylactic shock, termed Kounis syndrome, should be investigated in percutaneous coronary intervention to solve this complex and life-threatening condition. A team effort by cardiologist and anesthesiologist is essential for successful resuscitation. In general, the incidence of an anaphylactic reaction to cisatracurium is low, but a high serum IgE level in combination with a positive skin prick test in our patient was strongly suggestive of cisatracurium-induced Kounis syndrome. In addition, a cross-reaction between cisatracurium and rocuronium is reported.

Combination of bupivacaine scalp circuit infiltration with general anesthesia to control the hemodynamic response in craniotomy patients.

BACKGROUND Sudden and overwhelming increases in blood pressure (BP) and heart rate (HR) during incision of the scalp may give rise to morbidity or mortality in patients with intracranial pathology undergoing neurosurgery. A modification of the method proposed by Labat to abate this circumstantiality was applied in a group of patients receiving craniotomy. The modified method was to combine scalp circuit infiltration of local anesthetic with general anesthesia to control the hemodynamic response to craniotomy. METHODS Twenty-six patients scheduled to undergo craniotomy were randomly divided into two groups. Patients whose conditions or their current medication that might affect the stability of hemodynamics were excluded. In group A patients (N = 16) 25-30 ml of 0.25% bupivacaine was used for scalp circuit infiltration on the operation side, while in those of group B (N = 10) the same volume of 0.9% normal saline was used. After induction, anesthesia was maintained with 0.6% to 1.2% end-tidal isoflurane (ET-Iso) and 50% N2O in oxygen (N2O:O2 = 2 l/min:2 l/min). The end-tidal CO2 was kept within the range of 25-30 mmHg. BP and HR were recorded every five min before incision and then every two min after incision until one hour after induction. ET-Iso was also recorded every two min throughout a period of sixty min. If the BP and HR increased above 20% of the baseline (10 min before incision), thiopental 2.5 mg/kg and fentanyl 2 micrograms/kg were administered. If hypertension became sustained, the isoflurane concentration was adjusted until an acceptable level was obtained. RESULTS The mean BP during the surgery was 92 +/- 1 mmHg in group A and 92 +/- 7 mmHg in group B. The difference in BP between incision to 6 min after incision was statistically significant (P < 0.05). The mean HR during surgery was 101 +/- 5 beats/min in group B and 91 +/- 2 beats/min in group A, the difference of which was not statistically significant. All of the patients in group B required a deepened anesthesia to keep the BP and HR within the normal range, but no patient in group A had such need. The average concentration of ET-Iso during the 60 min period was 0.95 +/- 0.12% in group B and 0.41 +/- 0.01% in group A, respectively. The difference was statistically significant (P < 0.05). CONCLUSIONS Our results showed that scalp circuit infiltration with 0.25% bupivacaine significantly improved the cardiovascular stability and reduced the requirement of isoflurane during craniotomy. The routine use of bupivacaine scalp circuit infiltration in patients undergoing craniotomy should be considered.

Combination of topical EMLA with local injection of lidocaine : Superior pain relief after ferguson hemorrhoidectomy

ObjectiveTo determine whether a combination of topical anesthetic (EMLA) and local injection with lidocaine is better than lidocaine alone for pain relief after Ferguson hemorrhoidectomy. MethodsSixty patients scheduled for hemorrhoidectomy were randomized into 2 groups: (1) control group (CG, n=30) received neomycin ointment (5 g), and (2) EMLA group (EG, n=30) received EMLA (5 g), both agents applied topically after surgery. Before the surgical incision was made, lidocaine (10 mL of a 1% solution) was locally injected into all 60 patients. After surgery, analgesics were provided when necessary. The visual analog scale score was recorded at 4 time points: (1) upon arrival in the postanesthesia room, (2) 2 hours after arriving in the postanesthesia room, (3) between 9 and 10 PM on the first postoperative evening, and (4) on the first postoperative morning. The frequency of meperidine requests, 1-time catheterizations for urinary retention, and patient satisfaction with postoperative pain management, were also recorded. ResultsThe median visual analog scale scores and cumulative dosages of meperidine were significantly lower in the EG than the CG (P<0.05). Patient satisfaction with postoperative pain control was also significantly higher in the EG than the CG (P<0.01). No systemic complications occurred. DiscussionEMLA is considered a breakthrough in cutaneous analgesia, capable of reducing pain in many cutaneous procedures. Because Ferguson hemorrhoidectomy has been performed for years with ongoing concerns over postoperative pain, we felt that using EMLA could lower postoperative pain intensity and the number of requests for additional medication.

Attenuation of the catecholamine responses by electroacupuncture on Jen–Chung point during postoperative recovery period in humans

In this study, Jen-Chung (J-C) point was stimulated by electroacupuncture (EA) in 10 patients, and by placebo treatment in 10 controls, immediately after termination of inhalation for 15 min. During the postoperative recovery period, plasma catecholamine (CA) levels were assessed before (0) and 15 and 30 min after treatment. The time from cessation of inhalation to the first eye opening and to extubation did not differ between groups. The plasma catecholamine levels increased by 30% from 0 to 15 min in the control group but decreased by 6% in the EA group. The levels at 30 min were approximately the same as at time 0. The change in catecholamine levels from 0 to 15 min was significantly lower (P < 0.02) in the EA groups than the control group.

Paravertebral transcutaneous electrical nerve stimulation reduces movement during general anesthesia with isoflurane.

We evaluated paravertebral transcutaneous electrical nerve stimulation (TENS) as a means of enhancing anesthesia during hysterectomy. Patients were randomly assigned to experimental (n = 21) and control (n = 20) groups. Anesthesia with isoflurane was performed uniformly for all patients. Paravertebral (T6 and T7) TENS (50 mA, 15 Hz, continuously) was applied in the experimental group. After 15 min of isoflurane, a lower abdominal, skin-to-adipose-tissue incision was made. Seventeen of 21 patients in the experimental group showed no arm or leg movements during the incision, compared to 8 with 20 patients in the control group (P = 0.007). TENS deserves further exploration as an adjunct technique for general anesthesia.

The hypotensive effects of propofol at different sampling sites in cardiopulmonary bypass model.

BACKGROUND Although propofol has been widely used the uncertainties about its pharmacokinetics and pharmacodynamics are still in existence especially on acute infusion model. This study was designed to observe the changes of the arterial and superior vena cava blood concentrations of propofol during cardiopulmonary bypass and to see whichever site is more appropriate for pharmacodynamic studies of propofol. METHODS Eight patients undergoing cardiopulmonary bypass were infused rapidly with propofol. Samples were collected concurrently from bypass arterial side (Ca) and superior vena cava (Cv) side at 0, 0.5, 1, 1.5, 2, 5, 10, 20, 30, and 40 minutes after infusion and analyzed with high pressure liquid chromatography (HPLC). Arterial blood pressure was also recorded at the same time. RESULTS After administration, the concentration at Ca side was significantly higher than that at the corresponding Cv side from 0.5 to 5 min. The concentration at Ca side peaked at 0.5 min, then decreased rapidly and crossed the Cv curve at approximately 10 min. Thereafter Cv side concentration was slightly higher than that of Ca side. The mean arterial blood pressure decreased significantly from 1 to 20 min after injection. The change in Cv side was significantly consistent with the blood pressure change in the distribution phase (r = 0.78, r2 = 0.61 P < 0.001) (0 to 5 min). CONCLUSIONS There was a significant arteriovenous concentration difference of propofol after a rapid infusion in the cardiopulmonary bypass model. The hypotensive effect of propofol in the distribution phase can be predicted better on Cv side.