Martin I. Gold

Comparison of Propofol With Isoflurane for Maintenance of Anesthesia in Patients With Chronic Obstructive Pulmonary Disease: Use of Pulmonary Mechanics, Peak Flow Rates, and Blood Gases

Patients with chronic obstructive pulmonary disease (COPD) are usually anesthetized with an inhalation agent. After Institutional Review Board approval, informed consent was obtained from 60 patients with moderate to severe COPD according to a preoperative severity scoring system, which took into account history and objective findings. By using objective criteria, such patients were randomly assigned to receive propofol (group I) or isoflurane (group II) as primary maintenance agents. Preoperative and postoperative arterial blood gases, peak expiratory flow rates (PEFR), and chest X-rays were compared. Total dynamic compliance (CDYN) and V1 (% volume exhaled in first second) were measured using Pitot tube sidestream spirometry. A 1,000-mL super-syringe was used to measure total static compliance (CST). Measurements were recorded postintubation, midanesthesia, and pre-extubation. All patients received fentanyl, lidocaine, and propofol, 1.5 to 2.0 mg/kg, for induction. Succinylcholine, 1-1.5 mg/kg, was administered to facilitate intubation. Maintenance was with N2O-O2, vecuronium, and either propofol (n = 30) or isoflurane (n = 30). Both groups showed decreases in postoperative PaO2, SaO2, and PEFR (p 0.05). There were no significant chest X-ray differences. There were no differences between groups with respect to intraoperative pulmonary mechanics (p > 0.05). The only difference between groups was an increase in postoperative PaCO2 in group I and a decrease in group II (p < 0.05). Use of Pitot tube sidestream spirometry is a practical and noninvasive technique for monitoring pulmonary mechanics during anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Remifentanil versus propofol as adjuncts to regional anesthesia

STUDY OBJECTIVE To compare the safety and efficacy of remifentanil and propofol as adjuncts to regional anesthesia in patients undergoing orthopedic or urogenital surgery. DESIGN Prospective, randomized study. SETTING Multicenter university hospitals. PATIENTS 107 ASA physical status I, II, and III adult patients who underwent orthopedic or urogenital surgery with axillary, ankle, or spinal block. INTERVENTIONS Patients were randomized to receive either an infusion of remifentanil 0.2 microg/kg/min or propofol 100 microg/kg/min 5 minutes before nerve block placement. The infusions were decreased by 50% on block completion, increased by 50% for patient discomfort, and decreased by 50% for hypoventilation (< 8 breaths/min) or hemodynamic instability. MEASUREMENTS AND MAIN RESULTS Pain, discomfort, anxiety, and sedation were assessed by both patient and investigator. Vital signs and adverse events were recorded. Fewer patients in the remifentanil group experienced pain during block placement (6%), and were oversedated (7%) than patients in the propofol group (23% and 26%, respectively; p < 0.05). Hypoventilation during and after block placement (21% and 25%, respectively) and nausea and vomiting during and after block placement (60% and 21%, respectively) were more common in the remifentanil group than in the propofol group (0% and 3%; 17% and 6%, respectively; p < 0.05). The incidence of hypoventilation in remifentanil-treated patients was higher in patients over 65 years of age (p < 0.05), but was transient, resolving within minutes of discontinuing the infusion. CONCLUSIONS At the doses studied, remifentanil was more effective than propofol in minimizing pain without producing excessive sedation. Remifentanil was associated with more transient respiratory depression and short-term nausea. Our findings indicate that the initial remifentanil rate should be 0.1 microg/kg/min (50% lower than the studys initial rate) and should be further decreased an additional 50% in the elderly to minimize adverse effects.

A controlled investigation of propofol, thiopentone and methohexitone

This was a randomized study of 180 ASA physical status I and II patients, 60 in each group who received propofol (PROP), 2.5 mg·kg-1, thiopentone (THIO), 4 mg·kg-1, or methohexitone (METH), 1.5 mg·kg-1. Control values, followed by changes after induction and during a 3-min delay before intubation were recorded for the following parameters: heart rate (HR), systolic and diastolic blood pressures (SBP, DBP), respiratory rate (RR), end—tidal CO2 (PetCO2), and induction time (IT). In addition, the incidence of adverse reactions and time for recovery from anaesthesia were noted. The IT (mean ± SE) was 35 ± 1 sec for propofol, 35 ± 1.2 sec for thiopentone and 34 ± 1.4 sec for methohexitone. Ninety-three per cent of the PROP group fell asleep with one dose and required no additional doses. Fifty per cent of each of the THIO and METH groups required additional agents (p < 0.05). METH was associated with the highest elevation in HR, PROP the least (p < 0.05). PROP was associated with the most decrease in SBP and DBP and in addition respiratory depression (p < 0.05). The incidence of injection pain or excitatory activity was equal in the three groups with the exception that 14 patients who received METH developed hiccoughs while none did in the other groups. PROP was associated with the most rapid recovery, particularly with respect to the orientation time. We conclude that PROP is an effective alternative to barbiturate induction and that the published recommended doses of THIO and METH are often ineffective.RésuméVoici une étude aléatoire de 180 patients de statut physique ASA I et II, divisés en trois groupes de 60, qui ont reçu 2.5 mg·kg-1 de propofol (PROP), ou 4mg·kg-1 de thiopental (TWO), ou 1.5 mg·kg-1 de méthohexital (METH). Les valeurs-témoins, suivies de changements après ľinduction et durant un délai de trois minutes avant ľintubation, ont été enregistrées pour les paramètres suivants: fréquence cardiaque (FC), pression artérielle systolique et diastolique (PAS, PAD), fréquence respiratoire (FR), CO2 de fin ďexpiration (PetCO2), et temps ďinduction (TI). De plus, on a inscrit ľincidence de réactions adverses et le temps de rétablissement de ľahesthésie. Le TI (moyenne · SE) était de 35 · 1 sec pour le propofol, 35 · 1.2 sec pour le thiopental et 34 · 1.4 sec pour le méthohexital. Quatre-vingt-treize pour cent des patients du groupe PROP se sont endormis après ľadministration ďune dose et n’ont requis aucune dose additionnelle. Cinquante pour cent des patients du groupe THIO et du groupe METH ont requis des doses additionnelles des agents respectifs (p < 0.05). La plus grande augmentation de la FC fut associée au METH tandis que la plus petite fut associée au PROP (p < 0.05). Le PROP fut associé à la plus grande diminution de la PAS et de la PAD et à une dépression respiratoire (p < 0.05). Ľincidence de la douleur ou ďactivité ďexcitation à ľinjection était égale dans tes trois groupes à ľexception de 14 patients du groupe METH qui ont eu un hoquet alors que ceci ne s’est produit chez aucun patient des autres groupes. Le PROP a été associé au rétablissement le plus rapide, concernant plus particulièrement le temps ďorientation. Nous concluons que le PROP est une alternative efficace à ľinduction aux barbituriques et que les doses recommandées de THIO et de METH dans les publications sont souvent inefficaces.

Comparison of propofol with thiopental and isoflurane for induction and maintenance of general anesthesia

Propofol, a phenol compound with a short elimination half-life, was compared with thiopental and isoflurane for induction and maintenance of general anesthesia in 60 consenting ASA I, II, and III patients. The study was randomized and open label in design. Hemodynamically, the propofol patients showed a mean +/- SEM decrease in systolic blood pressure in comparison with the thiopental/isoflurane group at 2 (115.1 +/- 4.9 vs. 136.6 +/- 6.0 mmHg), 3 (125.7 +/- 5.1 vs. 149.4 +/- 5.6 mmHg), and 5 min (126.6 +/- 3.8 vs. 144.4 +/- 6.1 mmHg) postinduction and at intubation (135.2 +/- 4.7 vs. 157.8 +/- 6.0 mmHg) (p less than 0.05). The heart rate was lower in the propofol group throughout the induction period (p less than 0.05). Patients who received propofol were ready for discharge from the recovery room sooner (67.9 +/- 4.0 vs. 80.0 +/- 3.6 min) than the thiopental/isoflurane-treated patients (p less than 0.05). Propofol is as safe and effective for induction and maintenance of general anesthesia as thiopental and isoflurane.

The mini-Wright expiratory peak flow meter

The purpose of this study was to compare the recently modified mini-Wright peak flow meter with the Wright peak flow meter. One hundred adult patients were arbitrarily divided into two groups, based on their average peak flow on the mini-Wright device. A strong positive correlation in excess of 0.90 was shown. We believe that the smaller, cheaper device is as accurate as the Wright peak flow meter.RésuméL’objectif de cette étude était de comparer le mini débitmètre de pointe de Wright tel que modifié récemment avec le débitmètre de pointe de Wright. Cent patients d’ âge adulte furent divisés en deux groupes de façon arbitraire selon leur débit expiratoire de pointe moyen tel que mesuré par le mini-appareil de Wright. Une correlation positive importante dépassant 0.90 a été montrée et nous croyons que ce nouvel appareil qui est plus petit et coûte moins cher, est aussi précis que le débitmètre de pointe de Wright.

Comparison of Propofol with Isoflnrane for Maintenance of Anesthesia in Patients with Chronic Obstructive Pulmonary Disease: Use of Pulmonary Mechanics, Peak Flow Rates, and Blood Gases

Patients with chronic obstructive pulmonary disease (COPD) are usually anesthetized with an inhalation agent. After Institutional Review Board approval, informed consent was obtained from 60 patients with moderate to severe COPD according to a preoperative severity scoring system, which took into account history and objective findings. By using objective criteria, such patients were randomly assigned to receive propofol (group I) or isoflurane (group II) as primary maintenance agents. Preoperative and postoperative arterial blood gases, peak expiratory flow rates (PEFR), and chest X-rays were compared. Total dynamic compliance (CDYN) and V1 (% volume exhaled in first second) were measured using Pitot tube sidestream spirometry. A 1,000-mL super-syringe was used to measure total static compliance (CST). Measurements were recorded postintubation, midanesthesia, and pre-extubation. All patients received fentanyl, lidocaine, and propofol, 1.5 to 2.0 mg/kg, for induction. Succinylcholine, 1-1.5 mg/kg, was administered to facilitate intubation. Maintenance was with N2O-O2, vecuronium, and either propofol (n = 30) or isoflurane (n = 30). Both groups showed decreases in postoperative PaO2, SaO2, and PEFR (p < 0.05), but there were no differences between groups (p > 0.05). There were no significant chest X-ray differences. There were no differences between groups with respect to intraoperative pulmonary mechanics (p > 0.05). The only difference between groups was an increase in postoperative PaCO2 in group I and a decrease in group II (p < 0.05). Use of Pitot tube sidestream spirometry is a practical and noninvasive technique for monitoring pulmonary mechanics during anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)