We compared postoperative hepatic and renal functions and coagulation profiles in living donors undergoing right hepatectomy under isoflurane (n = 40) versus propofol (n = 40) anesthesia. After induction, anesthesia was maintained with isoflurane/air-O2 (group I) or propofol/air-O2 (group P) in addition to remifentanil and atracurium infusion in both groups. Aspartate aminotransferase, alanine aminotransferase, international normalized ratio (INR), activated partial thromboplastin time (aPTT), albumin, total bilirubin, blood urea nitrogen, creatinine, estimated glomerular filtration rate (GFR), platelet count, and hemoglobin levels were measured in the preoperative period, after end of the operation, and on the first, third, fifth and seventh postoperative days (PODs). INR was significantly increased on POD 3 and aPTT on POD 5 in group I compared with group P (P < .05). Albumin level was significantly lower in Group I on POD 1 and 3 (P < .05). GFR was significantly lower on POD 1 in the group I compared with group P (P < .05). The postoperative coagulation, GFR, and albumin values were superior following administration of propofol than isoflurane in donors who underwent living hepatectomy; however, both approaches were clinically safe, with no significant clinical difference.

BACKGROUND:

Transcutaneous vagal nerve stimulation is a promising treatment modality in patients suffering mood disorders and chronic pain, however, the mechanisms are still to be elucidated. A recently developed technique of EEG responses to electrical stimulation of the inner side of the tragus suggests that these responses are far field potentials, generated in the vagal system - Vagal Sensory Evoked Potentials (VSEP).

OBJECTIVE:

To reproduce the VSEP technique free from myogenic artifacts.

METHODS:

Fourteen ASA I-II patients scheduled for elective surgery in standardized Total Intravenous Anesthesia (TIVA) were enrolled. Transcutaneous electrical stimulation was applied to the inner side of the right tragus. Averaged EEG responses were recorded from the electrode positions C4-F4 and T4-O2 before and after induction of TIVA, during the maximal effect of the non-depolarizing muscle relaxing agent, cis-atracurium (C-AR) and after recovery from C-AR under TIVA.

RESULTS:

Typical response curves with P1, N1 and P2 peaks could be reproduced in all patients before and after anesthesia induction. The response curves disappeared during the C-AR action and re-appeared after recovery from C-AR under TIVA.

CONCLUSION:

The disappearance of the scalp responses to electrical tragus stimulation under the neuromuscular block suggests a muscular origin of these potentials.

The combination of ketamine and remifentanil seems to be associated with better analgesia and duration. The aim of this study was to evaluate whether a ketamine-remifentanil combination promotes improved postoperative analgesia.Prospective, randomized, double blind study of 40 patients undergoing video laparoscopic cholecystectomy. Anesthesia was performed with remifentanil, propofol, atracurium, and 50% oxygen. Group 1 (GI) patients received remifentanil (0.4 mcg.kg(-1).min(-1)) and ketamine (5 mcg.kg(-1).min(-1)) and Group 2 (G2) received remifentanil (0.4 mcg.kg(-1).min(-1)) and saline solution. Morphine 0.1mg.kg(-1) was administered at the end of the procedure, and postoperative pain was treated with morphine via PCA. We evaluated the severity of postoperative pain by a numerical scale from zero to 10 during 24 hours. We registered the time to the first analgesic supplementation, amount of morphine used in the first 24 hours, and adverse effects.There was a decrease in pain severity between extubation and other times evaluated in G1 and G2. There was no significant difference in pain intensity between the groups. There was no difference between G1 (22±24.9 min) and G2 (21.5±28.1min) regarding time to first dose of morphine and dose supplement of morphine consumed in G1 (29±18.4mg) and G2 (25.1±13.3mg).The combination of ketamine (5 mcg.kg(-1).min(-1)) and remifentanil (0.4mcg.kg(-1).min(-1)) for cholecystectomy did not alter the severity of postoperative pain, time to first analgesic supplementation or dose of morphine in 24hours.

BACKGROUND::

The acetylcholinesterase inhibitor, pyridostigmine, is prophylactically administered to mitigate the toxic effects of nerve gas poisoning. The authors tested the hypothesis that prolonged pyridostigmine administration can lead to neuromuscular dysfunction and even down-regulation of acetylcholine receptors.

METHODS::

Pyridostigmine (5 or 25 mg·kg·day) or saline was continuously administered via osmotic pumps to rats, and infused for either 14 or 28 days until the day of neuromuscular assessment (at day 14 or 28), or discontinued 24 h before neuromuscular assessment. Neurotransmission and muscle function were examined by single-twitch, train-of-four stimulation and 100-Hz tetanic stimulation. Sensitivity to atracurium and acetylcholine receptor number (quantitated by I-α-bungarotoxin) provided additional measures of neuromuscular integrity.

RESULTS::

Specific tetanic tensions (Newton [N]/muscle weight [g]) were significantly (P < 0.05) decreased at 14 (10.3 N/g) and 28 (11.1 N/g) days of 25 mg·kg·day pyridostigmine compared with controls (13.1-13.6 N/g). Decreased effective dose (0.81-1.05 vs. 0.16-0.45 mg/kg; P < 0.05) and decreased plasma concentration (3.02-3.27 vs. 0.45-1.37 μg/ml; P < 0.05) of atracurium for 50% paralysis (controls vs. 25 mg·kg·day pyridostigmine, respectively), irrespective of discontinuation of pyridostigmine, confirmed the pyridostigmine-induced altered neurotransmission. Pyridostigmine (25 mg·kg·day) down-regulated acetylcholine receptors at 28 days.

CONCLUSIONS::

Prolonged administration of pyridostigmine (25 mg·kg·day) leads to neuromuscular impairment, which can persist even when pyridostigmine is discontinued 24 h before assessment of neuromuscular function. Pyridostigmine has the potential to down-regulate acetylcholine receptors, but induces neuromuscular dysfunction even in the absence of receptor changes.

To assess the feasibility of measuring cord dorsum potentials (CDPs) in anesthetized clinically normal dogs after caudal nerve stimulation, determine the intervertebral site of maximum amplitude and best waveform of the CDP, and evaluate the effects of neuromuscular blockade.8 male and 4 female dogs (age, 1 to 5 years).Dogs were anesthetized, and CDPs were recorded via needles placed on the dorsal lamina at intervertebral spaces L1-2 through L7-S1. Caudal nerves were stimulated with monopolar electrodes inserted laterally to the level of the caudal vertebrae. Dogs were tested without and during neuromuscular blockade induced with atracurium besylate. The CDP latency and amplitude were determined from the largest amplitude tracings.CDPs were recorded in 11 of 12 dogs without neuromuscular blockade and in all dogs during neuromuscular blockade. The CDP was largest and most isolated at the L4-5 intervertebral space (3 dogs) or the L5-6 intervertebral space (9 dogs); this site corresponded to the segment of insertion of the first caudal nerve. Onset latencies ranged from 2.0 to 4.7 milliseconds, and there was no effect of neuromuscular blockade on latencies. Amplitudes of the CDPs were highly variable for both experimental conditions.CDPs were recorded from all dogs tested in the study; neuromuscular blockade was not critical for successful CDP recording but reduced muscle artifact. This technique may be useful as a tool to assess the caudal nerve roots in dogs suspected of having compressive lumbosacral disease or myelopathies affecting the lumbar intumescence.

It has been suggested that monitoring during total intravenous anaesthesia should include aspects of brain function. The current study used a manually adjusted target-controlled infusion of propofol for anaesthesia, guided to a bispectral index range of 55-60. Intra-operative responsiveness, as assessed by the isolated forearm technique, was compared with whether the bispectral index predicted/identified a patient's appropriate hand movements in responses to commands. Twenty-two women underwent major gynaecological surgery with total intravenous anaesthesia, propofol, remifentanil and atracurium. Sixteen women responded, on 80 occasions, with appropriate hand movements to commands during surgery, of which the bispectral index detected 47 (sensitivity 59%). The bispectral index suggested consciousness 220 times in the absence of movement responses (specificity 85%). The positive predictive value of a bispectral index response was 18%. While two women had vague recall about squeezing fingers, none had recall of surgery. For patients who responded more than once during surgery the bispectral index value associated with a response was not constant. Although there was no difference in the median (IQR [range]) effect site propofol concentration between intra-operative responses (2.0 (1.5-2.3 [1.2-4.0]) μg.ml(-1)) and eye opening after surgery (2.1 (1.7-2.8 [1.5-3.9]) μg.ml(-1)), the median (IQR [range]) bispectral index value at eye opening after surgery was significantly higher than that associated with responses during surgery: 75 (70-78 [51-93]) vs 61 (52-67 [37-80]) respectively, (p < 0.001). The manual control of propofol intravenous anaesthesia to target a bispectral index range of 55-60 may result in an unacceptable number of patients who are conscious during surgery (albeit without recall).

Airtraq™ is an optical laryngoscope that allows viewing of the vocal cords without a direct line of sight. The main objective of this prospective, randomized, controlled trial was to evaluate Airtraq intubation characteristics, mainly intubation time and cardiovascular changes in the pediatric patients.Fifty children of American Society of Anesthesiologists class I, 2-10 years of age were divided into 2 groups using sealed envelope technique. Children were premedicated with midazolam. Anesthesia was induced with sevoflurane, fentanyl, and atracurium. Patients were randomly allocated to be intubated with either Airtraq (Airtraq group) or Macintosh laryngoscope (Macintosh group). Intubation time, number of intubation attempts, optimization maneuvers, and ease of intubation were recorded. Hemodynamic variables were recorded before and after anesthetic induction, 1, 3, and 5 min after tracheal intubation.The mean age of children was 6.1 years. Compared with Macintosh group, the use of Airtraq was associated with shorter intubation time (51.6±26.7 s vs 22.8±6.1 s, respectively, P=0.001), less median number of intubation attempts 2 (1-2) versus 1 (1-1), P=0.001), more ease of intubation [2 (1-3) versus 1 (1-1), P=0.001] and less increase in the heart rate 5 min after intubation (P=0.007). No optimization maneuvers required for Airtraq laryngoscope (P=0.001).Airtraq decreases intubation time, number of attempts, and optimization maneuvers, less heart rate changes during intubation compared with Macintosh laryngoscope.

Non-depolarizing neuromuscular blocking agents (NMB) differ in pharmacokinetic and pharmacodynamic parameters. An anesthesiologist according to these similarities and differences is able to choose the least costly one if the same safety profile and same clinical benefit achieved with the different alternatives.The main objective of this study is to evaluate the economic and adverse drug reactions prevalence and differences between cisatracurium and atracurium the two non-depolarizing NMB drugs, which are widely used in adult patients undergoing surgery with general anesthesia in a teaching Hospital in Iran.A cost analysis and adverse drug reactions (ADR) monitoring were performed. Only direct costs were considered and data were collected through a prospective randomized study. Regardless of the type of surgery, 100 patients were randomly divided into two equal groups to receive either cisatracurium or atracurium by anesthesiologists. ADRs prevalence and cost differences between patients receiving one of the two non-depolarizing NMB agents were evaluated by independent sample t-test and Chi-square test respectively.No significant difference was observed between the two groups of patients in demographic data. There was no statistical difference in the ADR prevalence in both groups. The numbers of ADR within atracurium group was higher than cisatracurium group, but this distinction was not statistically significant (p > 0.05). It was significant difference in cost between the two neuromuscular blocking drugs (p < 0.05).According to our study it seems that atracurium and cisatracurium had similar safety profile and atracurium had a cost benefit relative to cisatracurium in initial loading doses. In patients with instability in hemodynamic parameters the cisatracurium was the appropriate choice.  

We report on an anesthetic experience with a 74-year-old female with Isaacs' syndrome, who underwent elective surgery for open rotator cuff repair. Isaacs' syndrome is a rare peripheral motor neuron disorder with clinical manifestations such as involuntary muscle twitching, cramps, mild weakness and increased sweating. To avoid prolonged neuromuscular blockade, the patient was observed with neuromuscular monitoring during total intravenous anesthesia with propofol, remifentanil, and atracurium. No adverse events were observed during the anesthetic management, and the patient recovered smoothly from the neuromuscular blockade. We describe the clinical characteristics of Isaacs' syndrome and its specific considerations in anesthesia.

To evaluate the effect of tramadol 2 mg/kg on haemodynamic response to tracheal intubation where the end tidal concentration of sevoflurane was kept constant at 1 MAC (2%).Double blind randomized controlled trial.The Aga Khan University Hospital, Karachi, from January 2009 to April 2009.Thirty-four patients scheduled for surgery under general anaesthesia were randomly allocated to two groups, sevoflurane alone (2%) or sevoflurane (2%) and tramadol (2 mg/kg) combination. Anaesthesia was induced with thiopentone and atracurium and with either tramadol or placebo according to group allocation. Sevoflurane was administrated along with N2O and oxygen through the face mask till end tidal minimum alveolar concentration (MAC) of one (2%) was achieved. Haemodynamic changes were noted at 1, 2 and 3 minutes post induction and every minute upto 7 minutes post-intubation and compared with baseline values.A significant difference in heart rate was seen at 2 and 3 minutes post-induction and 1, 2 and 3 minutes postintubation between two groups with values higher in sevoflurane alone group. No significant difference was seen in systolic, diastolic, and mean blood pressure compared to baseline between the two groups.HR and SBP values following laryngoscopy and tracheal intubation in both groups were less than 20% of baseline. Addition of tramadol 2 mg/kg to 1 MAC sevoflurane displayed further depression of chronotropic response to laryngoscopy and intubation as compared to sevoflurane alone following thiopentone and atracurium induction.