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Cyrus Motamed

Publications and source records attributed to Cyrus Motamed.

9 recordsLinked to original sources
PubMed2006

An analysis of postoperative epidural analgesia failure by computed tomography epidurography.

In this prospective study involving 125 patients, we analyzed epidural analgesia failure after major abdominal surgery using computed tomography (CT) epidurographies to compare the incidence of dislodgement of epidural catheters and leakage of solution from the epidural space between two groups of patients: patients with successful or failed epidural analgesia. Our hypothesis was that the incidence of dislodgement and leakage should be low when epidural analgesia is successful. A thoracic epidural catheter was inserted before general anesthesia and secured by subcutaneous tunneling. Bupivacaine (0.25%) was administered during surgery followed by continuous epidural analgesia with 0.125% bupivacaine (10 mL/h) and morphine (0.25 mg/h) for 48 h. Failure was defined as a visual analog scale pain score at rest more than 30 mm and/or interruption of epidural analgesia before 48 h for any reason. When failure was not due to unintentionally withdrawn, kinked catheters or adverse events (n = 11), a CT scan with contrast injection was performed. Control CT scans were also performed in patients with adequate analgesia (i.e., the success group). The incidence of failure was 24.8% (n = 31). CT scans in the failure group (n = 20) showed seven patients with catheters outside the epidural space, nine with normal distribution, one with unilateral spread, and three with leakage of solution outside the epidural space. In the success group, CT scans (n = 19) showed 11 patients with normal distribution, five with unilateral spread, and three with leakage. We conclude that the major cause of epidural analgesia failure was dislodgment of the catheter. CT scans were mostly useful for detecting leakage of injectate, which may be the early phase of dislodgment.

Abdominal Neoplasms↗
PubMed2005

Cardiac troponin I assessment and late cardiac complications after carotid stenting or endarterectomy.

PURPOSE: When compared with carotid endarterectomy (CEA), percutaneous carotid angioplasty with stent replacement (CAS) is a less invasive technique in the treatment of carotid stenosis. However, periprocedural hemodynamic instability still remains a challenge. This instability might lead to myocardial damage, which is now measured accurately by using cardiac troponin I (CTnI). METHODS: This study was designed to compare the periprocedural variation of CTnI in 150 consecutive patients scheduled to undergo CEA (n = 75) or CAS (n = 75). The levels of CTnI were measured until the third postoperative day in all patients. Short-term (1 month) and long-term (up to 5 years) postoperative cardiac outcome were assessed by means of chart review, regular follow-ups, and telephone calls. RESULTS: There was not any statistically significant difference between the 2 groups regarding the demographic characteristics and preprocedural medical status. The incidence of increase of CTnI (>0.5 ng/mL) was significantly higher in the CEA group (13%) compared with that in the CAS group (1%; P = .001). During the acute postprocedural period, the CAS group was significantly more prone to hypotension, requiring vasopressor therapy, whereas the CEA group had more hypertension, necessitating hypotensive medications (P < .001). At 5 years, the overall incidence of major cardiac complications (nonfatal myocardial infarction and death related to cardiac origin) was significantly more frequent in the CEA group (20% vs 5%, P < .01). CONCLUSION: The results of our study suggest that CAS yielded less myocardial damage in the short and long term when compared with CEA. Larger randomized multicenter trials with long-term outcomes are necessary to confirm our findings.

Aged↗
PubMed2005

Intubating laryngeal mask airway in morbidly obese and lean patients: a comparative study.

BACKGROUND: The intubating laryngeal mask airway (ILMA) was designed using the characteristics of healthy-weight subjects but was shown to be an effective airway device in morbidly obese patients. The authors compared airway management quality in morbidly obese and lean patients with use of the ILMA. METHODS: Fifty morbidly obese and 50 lean patients (mean body mass indexes, 42 and 27 kg/m, respectively) were enrolled in this prospective study. After induction of general anesthesia, characteristics of airway management were judged on safety and efficiency parameters, including success rate at ventilation and intubation and airway management quality criteria, such as the number of patients who required adjustment maneuvers, the number of failed tracheal intubation attempts, the total duration of airway management, and an overall difficulty visual analog scale score. RESULTS: The ILMA was successfully inserted and adequate ventilation through the ILMA was achieved in all 100 patients. The success rates of tracheal intubation through the ILMA were similar in obese and lean patients (96% and 94%, respectively). The numbers of failed blind tracheal access attempts and patients who required airway-adjustment maneuvers were significantly reduced in obese patients as compared with lean patients. Four obese patients experienced transient episodes of oxygen desaturation (oxygen saturation < 90%) before adequate bag ventilation was established with the ILMA. CONCLUSION: The authors confirmed that the ILMA was an efficient airway device for airway management of both lean and obese patients. In the conditions of this study, the authors observed that airway management with the ILMA was simpler in obese patients as compared with lean patients.

Adult↗
PubMed2004

Unanticipated difficult airway in anesthetized patients: prospective validation of a management algorithm.

BACKGROUND: Management strategies conceived to improve patient safety in anesthesia have rarely been assessed prospectively. The authors undertook a prospective evaluation of a predefined algorithm for unanticipated difficult airway management. METHODS: After a 2-month period of training in airway management, 41 anesthesiologists were asked to follow a predefined algorithm for management in the case of an unanticipated difficult airway. Two different scenarios were distinguished: "cannot intubate" and "cannot ventilate." The gum elastic bougie and the Intubating Laryngeal Mask Airway (ILMA) were proposed as the first and second steps in the case of impossible laryngoscope-assisted tracheal intubation, respectively. In the case of impossible ventilation or difficult ventilation, the IMLA was recommended, followed by percutaneous transtracheal jet ventilation. The patient's details, adherence rate to the algorithm, efficacy, and complications of airway management processes were recorded. RESULTS: Impossible ventilation never occurred during the 18-month study. One hundred cases of unexpected difficult airway were recorded (0.9%) among 11,257 intubations. Deviation from the algorithm was recorded in three cases, and two patients were wakened before any alternative intubation technique attempt. All remaining patients were successfully ventilated with either the facemask (89 of 95) or the ILMA (6 of 95). Six difficult-ventilation patients required the ILMA before completion of the first intubation step. Eighty patients were intubated with the gum elastic bougie, and 13 required a blind intubation through the ILMA. Two patients ventilated with the ILMA were never intubated. CONCLUSION: When applied in accordance with a predefined algorithm, the gum elastic bougie and the ILMA are effective to solve most problems occurring during unexpected difficult airway management.

Adult↗
PubMed2003

Potentiation of mivacurium blockade by low dose of pancuronium: a pharmacokinetic study.

BACKGROUND: Mivacurium is potentiated by pancuronium to a much greater extent than other relaxants. In a previous investigation we suggested that this potentiation could be due to the ability of pancuronium to inhibit plasma cholinesterase activity, but we did not measure plasma concentrations of mivacurium. In the current study we performed a pharmacokinetic analysis by measuring the plasma concentration of mivacurium when preceded by administration of a low dose of pancuronium. METHODS: After induction of general anesthesia with propofol and fentanyl and orotracheal intubation, 10 patients (pancuronium-mivacurium group) received 15 microg/kg pancuronium followed 3 min later by 0.1 mg/kg mivacurium, whereas 10 other patients (mivacurium group) received saline followed by 0.13 mg/kg mivacurium 3 min later. Plasma cholinesterase activity was measured before and 3 and 30 min after pancuronium dosing in the pancuronium-mivacurium group and was measured before and after administration of saline in the mivacurium group. Arterial plasma concentrations of mivacurium and its metabolites were measured at 0.5, 1, 1.5, 2, 4, 10, 20, and 30 min after injection. Neuromuscular blockade was assessed by mechanomyography. RESULTS: Plasma cholinesterase activity decreased by 26% in the pancuronium-mivacurium group 3 min after injection of pancuronium (P < 0.01) and returned to baseline values 30 min later; however, no significant variation was observed in the mivacurium group. The clearances of the two most active isomers (Cis-Trans and Trans-Trans) were lower in the pancuronium-mivacurium group (17.6 +/- 5.1, 14.7 +/- 5.3 ml. min-1. kg-1, respectively) than in the mivacurium group (32.4 +/- 20.2, 24.8 +/- 13.5 ml. min-1. kg-1; P < 0.05). CONCLUSIONS: A subparalyzing dose of pancuronium decreased plasma cholinesterase activity and the clearance of the two most active isomers of mivacurium. Pancuronium potentiates mivacurium more than other neuromuscular blocking agents because, in addition to its occupancy of postsynaptic acetylcholine receptors, it slows down the hydrolysis of mivacurium.

Adolescent↗
PubMed2002

Sevoflurane and isoflurane, but not propofol, decrease mivacurium requirements over time.

PURPOSE: Volatile anesthetic agents potentiate neuromuscular blockade, but the magnitude of potentiation appears to be time dependent. The time course of this interaction was studied by measuring mivacurium infusion rates during sevoflurane, isoflurane and propofol anesthesia. METHODS: After informed consent, anesthesia was induced in 48 ASA physical status I-II adults with propofol, fentanyl and mivacurium 0.25 mg.kg(-1) and maintained with N(2)O (60%) and one of the three agents chosen at random: sevoflurane 1.9%; isoflurane 1.2%; or propofol 100-150 microgram.kg(-1).min(-1). Train-of-four stimulation was applied every 15 sec to the ulnar nerve. Neuromuscular blockade was monitored with accelerometry. At 5% recovery of the first twitch (T1), a mivacurium infusion was started and adjusted every five minutes to maintain 90-95% T1 depression. RESULTS: The time to 5% T1 recovery after the initial dose was similar in all groups (13-15 min). Fifteen minutes after the start of the infusion mivacurium requirements were greater (P < 0.05) in the propofol group (7.5 +/- 1.7 microgram.kg(-1).min(-1); mean +/- SD) than in either isoflurane (4.7 +/- 1.6 microgram.kg(-1).min(-1)) or sevoflurane (4.5 +/- 1.5 microgram.kg(-1).min(-1)) group. Then, the rate remained stable for propofol (6.2 +/- 1.4 microgram.kg(-1).min(-1) after 90 min of infusion) while it decreased with isoflurane to 2.9 +/- 1.6 microgram.kg(-1).min(-1) at 90 min (P < 0.05 vs propofol) and to 1.4 +/- 1.0 microgram.kg(-1).min(-1) in the sevoflurane group (P < 0.05 vs propofol and isoflurane). CONCLUSION: Sevoflurane and isoflurane do not prolong the effect of a bolus dose of mivacurium, but potentiation increases with time from 30-105 min of exposure. This interaction is greater with sevoflurane than isoflurane.

Adult↗
PubMed2002

Systolic blood pressure, not BIS, is associated with movement during laryngoscopy and intubation.

OBJECTIVE: To compare bispectral index (BIS) values to hemodynamic variations, in order to evaluate adequacy of anesthesia during orotracheal intubation with muscle relaxants. METHODS: Forty-one patients ASA I-II, scheduled for elective peripheral surgery under general anesthesia with tracheal intubation were enrolled in the study. Fentanyl/thiopental followed by vecuronium were used for induction. Onset of relaxation was monitored at the orbicularis occuli (OO) muscle using train-of-four stimulation. Intubation was performed when no response at the OO was detected visually. Intubating conditions were noted. The "isolated forearm" technique was used to detect movement during laryngoscopy/intubation. BIS values, pulse rate (PR), and systolic pressure were recorded before induction, during laryngoscopy/intubation and 60 sec after intubation. RESULTS: Although intubating conditions were clinically adequate for all patients, ten out of 41 had movement of the isolated arm during laryngoscopy/intubation. BIS values were not significantly different for these patients: 67 (55-83) compared to those who had no movement: 60 (35-80), P = 0.6. During laryngoscopy, PR increased for all patients while systolic pressure increased significantly only in patients who moved: 125 (100-136) mmHg vs those who did not: 108 (67-140), P < 0.05. CONCLUSION: Systolic pressure elevations were associated with inadequate anesthesia as evaluated by the "isolated forearm" technique, during laryngoscopy/intubation. BIS values were not different between groups, suggesting that systolic blood pressure may be a better predictor of inadequate anesthesia under the circumstances described.

Adjuvants, Anesthesia↗