Effects of the concurrent use of a reduced dose of propofol with divided supplemental remifentanil and moderate hyperventilation on duration and morphology of electroconvulsive therapy-induced electroencephalographic seizure activity: A randomized controlled trial.

STUDY OBJECTIVE: The clinical adequacy of electroconvulsive therapy (ECT) depends on not only seizure duration but also seizure amplitude and postictal suppression. The objective of this study was to evaluate the effects of combination of a reduced dose of propofol and moderate hyperventilation on seizure duration and electrical stimulus requirement for adequate ictal amplitude and postictal suppression. DESIGN: Prospective, randomized, controlled trial. SETTING: Operating room at a municipal hospital. PATIENTS: Sixty ASA physical status I or II patients scheduled to receive a total of >300 ECT treatments. INTERVENTIONS: Patients were randomly assigned to have the three interventions: the use of a standard dose (1mg/kg) of propofol and normoventilation (ETCO2 of 40-45mmHg) (group P/N), the use of a reduced dose (0.5mg/kg) of propofol with divided remifentanil injections and normoventilation (group RP/N), and the use of a reduced dose of propofol with divided remifentanil injections and moderate hyperventilation (ETCO2 of 30-35mmHg) (group RP/H). Patients in groups RP/N and RP/H received remifentanil 1µg/kg followed by propofol 0.5mg/kg for unconsciousness and thereafter remifentanil 1µg/kg immediately before the electrical stimulus. MEASUREMENTS AND MAIN RESULTS: Patients in group RP/H had significantly longer durations of electroencephalographic (EEG) seizures in the early phase of the ECT course (P<0.05) and lower intensities of electrical stimulus in the late phase of the ECT course (P<0.05) than those in groups P/N and RP/N. CONCLUSION: A reduced dose of propofol combined with divided supplemental remifentanil under moderate hyperventilation during ECT may contribute to reduced electrical dosage due to the ability of its augmentation of seizure amplitude and postictal suppression in the late phase of the ECT course.

[Anesthetic management for nasal foreign body removal in children].

Migration of a foreign body into the nasal cavity accidentally occurred in three children aged 2 yr. All procedures for removal were performed under general anesthesia. Two patients underwent slow anesthetic induction with sevoflurane and their tracheas were intubated under spontaneous breathing without neuromuscular blocking agents. One patient underwent rapid sequence induction with cricoid pressure to prevent aspiration. Anesthetic courses of the three patients were stable, and the foreign bodies were successfully removed without any complications. Since a nasal foreign body can cause occurrence of its aspiration into the trachea due to crying or reduction of muscle tone, special attention should be paid for safe management of the airway and/or anesthesia throughout the procedure.

Effect of divided supplementation of remifentanil on seizure duration and hemodynamic responses during electroconvulsive therapy under propofol anesthesia.

PURPOSE: Although a reduced dose of propofol combined with remifentanil is often used in anesthesia for electroconvulsive therapy (ECT), there have been few studies in which the optimal technique for injection of remifentanil was examined in detail. The aim of this study was to evaluate the effects of single and divided injection of remifentanil combined with propofol on seizure duration and hemodynamic responses during ECT. METHODS: Twenty-six ASA I-II patients were enrolled in this study and received a total of 78 ECTs. Each patient received propofol 1.2 mg/kg (group P), remifentanil 1 µg/kg followed by propofol 0.5 mg/kg (group R1), and remifentanil 1 µg/kg followed by propofol 0.5 mg/kg and thereafter remifentanil 2 µg/kg (group R2). Succinylcholine 1 mg/kg was used for muscle paralysis after loss of consciousness. RESULTS: Although mean motor seizure durations were significantly longer in groups R1 and R2 than in group P (P < 0.05), they were similar in groups R1 and R2. Although the percentage increases in mean arterial pressure after ECT were significantly smaller in groups P (P < 0.01) and R2 (P < 0.05) than in group R1, they did not significantly differ between groups P and R2. CONCLUSIONS: Divided use of remifentanil at 1 and 2 µg/kg combined with propofol 0.5 mg/kg produces an acceptable outcome in both seizure duration and hemodynamic stability during ECT compared with the standard hypnotic doses of propofol alone or remifentanil 1 µg/kg followed by propofol 0.5 mg/kg.

Efficacy of the Airtraq(®) laryngoscope with a fiberoptic bronchoscope compared with that of Airtraq(®) alone for tracheal intubation: a manikin study.

PURPOSE: Successful intubation using the Airtraq(®) requires optimal positioning of the glottis in the middle of the viewfinder. If the glottic view cannot be optimized, some glottic manipulation is essential for the Airtraq-assisted successful intubation. We evaluated the efficacy of the combined use of the Airtraq and a fiberoptic bronchoscope (FOB) compared with that of the Airtraq alone for tracheal intubation in simulated airway scenarios. METHODS: Eight anesthesia providers (four staff and four residents) were enrolled in this study. The participants intubated the trachea of the ALS Simulator manikin in five tongue edema scenarios simulating modified Cormack-Lehane grade 1, 2a, 2b, 3, and 4 views and one cervical immobilization scenario. RESULTS: No significant difference in the rate of successful intubation was detected between the combined use and the use of Airtraq alone in all scenarios. However, the duration of intubation attempts with the combined use was significantly shorter in difficult laryngoscopy scenarios (Cormack-Lehane grade 2b-4) (P < 0.01) and were significantly longer in easy laryngoscopy scenarios (grade 1 and 2a) (P < 0.05) than those with Airtraq alone. The rate of successful intubation and duration of intubation attempts were similar between the anesthetists and residents in each intubation technique in all scenarios. CONCLUSION: The combined use of Airtraq(®) and a FOB enables rapid intubation in simulated difficult airway scenarios compared with intubation using Airtraq alone, and the speed of intubation performed by anesthetists and residents is similar in all airway scenarios.

Effects of sepsis on the neuromuscular blocking actions of d-tubocurarine on rat adductor and abductor laryngeal muscles.

PURPOSE: We evaluated the effects of sepsis on the neuromuscular blocking actions of d-tubocurarine (dTc) in the lateral cricoarytenoid (LCA) and posterior cricoarytenoid (PCA) muscles, an adductor muscle and an abductor muscle of the vocal cords, respectively, in vitro. METHODS: Sepsis was induced in rats by cecal ligation and puncture (CLP) to elicit panperitonitis. Electromyograms (EMGs) and endplate potentials (EPPs) were recorded from the LCA and PCA muscles of CLP-operated septic rats and sham-operated nonseptic rats, using extracellular and intracellular microelectrodes, respectively. RESULTS: EMG and EPP (amplitude and quantum content) were depressed by dTc, but the dTc-induced neuromuscular blocking effects were attenuated by sepsis. The suppressive effects of dTc on EMG and EPP (amplitude and quantum content) were less intense in the LCA muscle than in the PCA muscle under both sepsis and nonsepsis conditions. CONCLUSION: Our study shows that sepsis has a depressive effect on dTc-induced neuromuscular blocking actions at both the adductor and abductor muscles of vocal cords in the larynx.

[Case of laryngeal edema occurring after tracheal extubation presumably due to antihypertensive medications].

A 61-year-old woman underwent microlaryngeal surgery for a vocal cord polyp. Anesthesia was induced with propofol, and vecuronium was given after loss of consciousness. The trachea was intubated smoothly with a Portex tracheal tube with a 6.0 mm in inner diameter and the cuff was inflated to the minimal occlusion volume. Anesthesia was maintained with O2-air-sevoflurane. The surgical procedure was completed without any troubles. Immediately after tracheal extubation, she developed dyspnea with stridor. As marked laryngeal edema was found by direct vision with the aide of a laryngoscope, reintubation was performed and methylprednisolone was administered intravenously. She was extubated on the next day, after confirmation of the tracheal tube cuff leak following the reduction in the cuff pressure. At this time, fiberoptic bronchoscopy revealed that the laryngeal edema had disappeared. For the past history, she had taken amlodipine for 10 years and candesertan for 2 months, and had often experienced dyspnea. It should be kept in mind that preoperative antihypertensive medications might have an impact on occurrence of perioperative laryngeal edema.

[Efficacy of spinal anesthesia with small-dose lidocaine in ambulatory prostate biopsy procedures for elderly patients : comparison with propofol anesthesia].

BACKGROUND: Opinions differ as to what is more appropriate anesthetic technique for elderly patients undergoing ambulatory surgery. The objective of this study is to compare the efficacy and safety of spinal anesthesia with small-dose lidocaine and those of propofol general anesthesia in elderly patients undergoing ambulatory prostate biopsy. METHODS: Eighty ASA physical status I x II patients aged older than 65 year were randomized to receive either spinal anesthesia with 1% hyperbaric lidocaine 1 ml (10 mg) (group L) or general anesthesia with 1.0 mg x kg(-1) of propofol injected at 180 mg x kg(-1) x hr(-1) followed by continuous infusion at 8 mg x kg(-1) x hr(-1) (group P). RESULTS: Significantly higher incidences of intraoperative hypotension and respiratory depression were found in the group P compared with the group L (P < 0.05). There were no major postoperative side effects, including transient neurologic symptoms and delirious sate, in either group. Both anesthetic techniques resulted in a high rate of patient satisfaction. Total perioperative costs were significantly lower in the group L compared with the group P (P < 0.01). CONCLUSIONS: Spinal anesthesia with 10 mg of hyperbaric 1% lidocaine may be more preferable to propofol anesthesia in elderly patiens undergoing ambulatory prostate biopsy, with respect to safety and costs.

Severe hyperglycemic shock associated with hepatic portal venous gas.

We report a case of hyperglycemic shock associated with hepatic portal venous gas. A 79-year-old woman with post-stroke depression developed severe tachycardiac atrial fibrillation and hypotension due to hypovolemia caused by severe hyperglycemia, as well as showing disseminated intravascular coagulation (DIC). Continuous intravenous infusion of insulin and volume loading with normal saline gradually achieved normalization of the serum glucose level and hemodynamic stability. However, the DIC did not resolve, and abdominal computed tomography (CT) revealed hepatic portal venous gas (HPVG) in the left lobe of the liver. Surgery was thus considered mandatory. However, because severe hemodynamic lability occurred again immediately after the CT examination, and persisted, surgery could not be performed, and the patient died of septic shock due to bowel perforation. It was concluded that the underlying causes of DIC should be sought promptly, without delay.

A comparison of intravenous-based and epidural-based techniques for anesthesia and postoperative analgesia in elderly patients undergoing laparoscopic cholecystectomy.

PURPOSE: We wished to compare the effectiveness of intravenous-based (IV) and epidural-based (EPI) techniques for anesthesia and postoperative analgesia in elderly patients undergoing laparoscopic cholecystectomy. Effectiveness was compared in terms of reduction of postoperative pain and adverse events, and achieving a high level of patient satisfaction. METHODS: Thirty American Society of Anesthesiologists (ASA) physical status I-II patients aged more than 65 years, scheduled for laparoscopic cholecystectomy, were enrolled in this study. The patients in the IV group (n = 15) received modified neurolept anesthesia with droperidol 0.2 mgxkg(-1) and pentazocine 0.15-0.3 mgxkg(-1) (maximum dose of 1.0 mgxkg(-1)) and 60% nitrous oxide in oxygen, followed by postoperative intravenous infusion of 20 microgxml(-1) buprenorphine, provided with a patient-controlled analgesia pump programmed to deliver a bolus of 0.5 ml with a lockout interval of 15 min and a background infusion of 0.5 mlxh(-1). The patients in the EPI group (n = 15) had combined epidural analgesia and general anesthesia with sevoflurane and 60% nitrous oxide in oxygen, followed by the epidural infusion of a 0.125% bupivacaine and 5 microg x ml(-1) buprenorphine mixture by means of an on-demand analgesic system (bolus of 2 ml, lockout interval of 60 min, and background infusion of 2 mlxh(-1)). RESULTS: The quality of postoperative analgesia was similar in the two groups. The incidences of intraoperative hypotension and bradycardia and postoperative hypotension were significantly lower in the IV group than in the EPI group (P < 0.05). A significantly higher level of patient satisfaction was found in the IV group compared with that in the EPI group (P < 0.05). The major contributor to dissatisfaction in the EPI group was anxiety or discomfort associated with the epidural procedures. CONCLUSION: Modified neurolept anesthesia with pentazocine and postoperative i.v. analgesia with buprenorphine were superior to epidural-based techniques, in terms of hemodynamic stability and patient satisfaction, in elderly patients undergoing laparoscopic cholecystectomy.

A comparison of spinal anesthesia with small-dose lidocaine and general anesthesia with fentanyl and propofol for ambulatory prostate biopsy procedures in elderly patients.

STUDY OBJECTIVE: To compare operating conditions, intraoperative adverse events, recovery profiles, postoperative adverse effects, patient satisfaction, and costs of small-dose lidocaine spinal anesthesia with those of general anesthesia using fentanyl and propofol for elderly outpatient prostate biopsy. DESIGN: Prospective, randomized, blind study. SETTING: Outpatient anesthesia unit at a municipal hospital. PATIENTS: 80 ASA physical status I and II patients, aged 65 to 80 years, scheduled for outpatient prostate biopsy. INTERVENTIONS: Patients were assigned to receive either spinal anesthesia with 10 mg of hyperbaric 1% lidocaine (L group, n=40) or anesthetic induction with fentanyl 1 microg.kg-1 IV and 1.0 mg.kg-1 propofol injected at 90 mg.kg-1.h-1, followed by continuous infusion at 6 mg.kg-1.h-1 (F/P group, n=40). MEASUREMENTS AND MAIN RESULTS: Both anesthetic techniques provided acceptable operating conditions for the surgeon. However, a significantly higher frequency of intraoperative hypotension was found in the F/P group than in the L group (P<0.05). Time to home readiness was shorter in the F/P group (P<0.05). Both techniques had no major postoperative adverse effects and resulted in a high rate of patient satisfaction. Total costs were significantly lower in the L group than in the F/P group (P<0.01). CONCLUSIONS: Spinal anesthesia with 10 mg of hyperbaric 1% lidocaine may be a more suitable alternative to general anesthesia with fentanyl and propofol for ambulatory elderly prostate biopsy in terms of safety and costs.

Experimental incision-induced pain in human skin: effects of systemic lidocaine on flare formation and hyperalgesia.

In order to try to gain a better understanding of the mechanisms of post-operative pain, this study was designed to psychophysically determine physiological and pharmacological characteristics of experimental pain induced by a 4-mm-long incision through the skin, fascia and muscle in the volar forearm of humans. In experiment 1, the subjects (n=8) were administered lidocaine systemically (a bolus injection of 2mg/kg for a period of 5 min followed by an intravenous infusion of 2mg/kg/h for another 40 min), and then the incision was made. In experiment 2, cumulative doses of lidocaine (0.5-2mg/kg) were systemically injected in the subjects (n=8) 30 min after the incision had been made, when primary and secondary hyperalgesia had fully developed. Spontaneous pain was assessed using the visual analog scale (VAS). Primary hyperalgesia was defined as mechanical pain thresholds to von Frey hair stimuli (from 7 to 151 mN) in the injured area. The area of secondary hyperalgesia to punctate mechanical stimuli was assessed using a rigid von Frey hair (151 mN). Flare formation was assessed in the first experiment using a laser doppler imager (LDI). Pain perception was maximal when the incision was made and then rapidly disappeared within 30 min after the incision had been made. Primary hyperalgesia was apparent at 15 min after the incision had been made and remained for 2 days. The incision resulted in a relatively large area of flare formation immediately after the incision had been made. The area of flare began to shrink within 15 min and was limited to a small area around the injured area at 30 min after incision. Secondary hyperalgesia was apparent at 30 min after incision and persisted for 3h after incision and then gradually disappeared over the next 3h. In experiment 1, pre-traumatic treatment with systemic lidocaine suppressed primary hyperalgesia only during the first 1h after the incision had been made. The lidocaine suppressed the development of flare formation without affecting the pain rating when the incision was made. The development of secondary hyperalgesia continued to be suppressed after completion of the lidocaine infusion. In experiment 2, post-traumatic treatment with lidocaine temporarily suppressed primary as well as secondary hyperalgesia that had fully developed; however, the primary and secondary hyperalgesia again became apparent after completion of the lidocaine administration. These findings suggest that pre-traumatic treatment with lidocaine reduces the excessive inputs from the injured peripheral nerves, thus suppressing development of flare formation and secondary hyperalgesia through peripheral and central mechanisms, respectively. Pre-traumatic treatment with lidocaine would temporarily stabilize the sensitized nerves in the injured area, but the nerves would be sensitized after completion of the administration. Post-traumatic treatment with lidocaine reduced primary and secondary hyperalgesia that had fully developed. However, the finding that the suppressive effect of lidocaine on secondary hyperalgesia was temporary suggests that the development and maintenance of secondary hyperalgesia are caused by different mechanisms.

Different mechanisms of development and maintenance of experimental incision-induced hyperalgesia in human skin.

BACKGROUND: To determine the mechanisms of postoperative pain, the effects of local anesthesia on development and maintenance of surgical incision-induced hyperalgesia were evaluated in a crossover, double-blinded, placebo-controlled human study using 17 subjects. METHODS: An experimental 4-mm-long incision through skin, fascia, and muscle was made in the volar forearm of each subject. In experiment 1, 1% lidocaine or saline in a volume of 0.2 ml was subcutaneously injected into the incision site pretraumatically and posttraumatically. In experiment 2, a 5-cm-long strip of skin was subcutaneously injected with 0.2 ml of 1% lidocaine near the incision site pretraumatically and posttraumatically. Flare, spontaneous pain, and primary and secondary hyperalgesia to punctate mechanical stimuli were assessed after the incision had been made. RESULTS: Pretraumatic lidocaine injection prevented the occurrence of spontaneous pain and development of flare formation that was found surrounding the incision site immediately (1 min) after the incision had been made. The lidocaine suppressed primary hyperalgesia more effectively than did posttraumatic block, but only for the first 4 h after the incision. The preincision block prevented development of secondary hyperalgesia, whereas posttraumatic block did not significantly affect the fully developed secondary hyperalgesia. The area of flare formation and the area of secondary hyperalgesia did not extend over the strip of the skin that had been pretraumatically anesthetized, whereas the posttraumatic block did not significantly reduce the area of fully developed secondary hyperalgesia. CONCLUSIONS: Pretraumatic injection of lidocaine reduces primary hyperalgesia more effectively than does posttraumatic injection, but only for a short period after incision. The spread of secondary hyperalgesia is mediated peripheral nerve fibers, but when secondary hyperalgesia has fully developed, it becomes less dependent on or even independent of peripheral neural activity originating from the injured site.

Prophylactic IM small-dose phenylephrine blunts spinal anesthesia-induced hypotensive response during surgical repair of hip fracture in the elderly.

UNLABELLED: In a double-blinded, placebo-controlled, randomized study, we evaluated the effect of prophylactic IM phenylephrine at doses of 1.5 and 3 mg on hyperbaric tetracaine spinal anesthesia-induced hypotension in 90 normotensive and hypertensive patients aged >65 yr undergoing surgery for hip fracture. Thirty normotensive patients received 1.5 or 3 mg of phenylephrine IM (N/P-1.5 and N/P-3.0 groups; n = 15 in each), whereas controls received saline (N/C group; n = 15), and 45 hypertensive patients were treated in a similar manner (H/P-1.5, H/P-3.0, and H/C groups; n = 15 in each). All groups had a peak sensory block height of T9, with a range of T8 to T10. The incidence of hypotension (>25% decrease in mean arterial blood pressure [MAP] from baseline) was significantly lower in the patients who received phenylephrine 1.5 or 3 mg than in the controls, both in the normotensive and hypertensive groups (P < 0.01). The N/P-3.0 and N/P-1.5 groups and the H/P-3.0 group had significantly lower percentage reductions in MAP (P < 0.05) and required significantly smaller doses of rescue IV ephedrine (P < 0.05) than did the N/C group or the H/C group. The H/P-1.5 group also required significantly less rescue IV ephedrine (P < 0.05), although it was not sufficient to significantly attenuate the percentage decrease in MAP compared with that in the H/C group. Bradycardia (heart rate <50 bpm) as an adverse effect after IM administration of phenylephrine was not observed in any of the groups. Hypertension (MAP >20% increase from baseline) after medication occurred in the N/P-3.0 and H/P-3.0 groups, but not in the N/P-1.5 and H/P-1.5 groups. We conclude that prophylactic IM injection of 1.5 mg of phenylephrine is a safe (defined as the inhibition of bradycardia and hypertension) and effective means of reducing the incidence of hypotension associated with spinal anesthesia in normotensive and hypertensive elderly patients. IMPLICATIONS: We evaluated the efficacy and safety of small-dose IM phenylephrine for prophylaxis against spinal anesthesia-induced hypotension in normotensive and hypertensive elderly patients. Phenylephrine 1.5 mg IM was effective for reducing the incidence of hypotension and avoided adverse effects.