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Biomedical subjects

J Lerman

Publications and source records attributed to J Lerman.

At least 37 records · Page 2Linked to original sources
PubMed1998

Interaction of vecuronium and atracurium during halothane anaesthesia in children.

The combination of vecuronium and atracurium was studied in 60 children of ASA physical status 1 or 2. In part I, the dose-response relationships were determined in 30 children who were randomly assigned to receive a single bolus of 0.02, 0.025 or 0.03 mg kg-1 of vecuronium or 0.075, 0.01 or 0.0125 mg.kg-1 of atracurium. The evoked electromyogram of the adductor pollicis brevis muscle to train-of-four stimulation was monitored. The speed of onset of the neuromuscular blockade was determined by a 95% depression of the train-of-four whereas the recovery index was established at 75% recovery of T1. In part II, 30 children were randomly assigned to receive 2 x ED95 of vecuronium, 2 x ED95 of atracurium, or a combination of 1 x ED95 of vecuronium + 1 x ED95 of atracurium. This study showed that the ED50 and ED95 for vecuronium were 0.021 mg.kg-1 and 0.037 mg.kg-1 and for atracurium 0.11 mg.kg-1 and 0.30 mg.kg-1, respectively. The slopes of the dose-response relationships were significantly different (p < 0.001). With vecuronium alone, the speed of onset of neuromuscular blockade was significantly slower (p < 0.001) and the duration of action less (p < 0.001) than that with atracurium alone or with the combination. There were no differences between atracurium and the combination of both medications. The recovery index was similar for all groups. We conclude that the dose-response relationships of vecuronium and atracurium in children undergoing halothane anaesthesia are not parallel and the neuromuscular effects of vecuronium and atracurium are neither additive nor synergistic. While vecuronium has a shorter duration of action than atracurium, this feature is not apparent when it is combined with atracurium in equipotent doses. Recovery is rapid and not prolonged when these two drugs are combined.

Anesthesia, Inhalation↗
PubMed1997

Subhypnotic propofol does not treat postoperative vomiting in children after adenotonsillectomy.

PURPOSE: To investigate the efficacy of a subhypnotic dose of propofol to treat vomiting in children after adenotonsillectomy. METHODS: Two hundred and fifty-two children, aged 2-12 yr, underwent a standardized anaesthetic opioid administration, and postoperative care after adenotonsillectomy, adenoidectomy or tonsillectomy. A prospective, double-blinded, placebo-controlled study was performed in 70 of the patients who retched or vomited after surgery and who had intravenous access. Patients were assigned randomly to receive either 0.2 mg.kg-1) propofol (n = 35), or placebo (intralipid 10%, n = 35). RESULTS: The overall incidence of vomiting during the first 18-24 hr was 50%. Of those who had received propofol after the first episode of vomiting, 63% relapsed requiring a rescue antiemetic compared with 57% of those who had received intralipid (P = NS). Of the children who received propofol, 54% experienced pain on injection and 46% were mildly sedated compared with 3% and 11%, respectively, in the placebo group (P < 0.003). CONCLUSION: We conclude that an intravenous bolus of 0.2 mg.kg-1 propofolis not effective in the treatment of postoperative vomiting in children after adenotonsillectomy when a standardized anaesthetic with thiopentone, halothane, nitrous oxide, and 1.5 mg.kg-1 codeine phosphate is used, but it does cause sedation and pain on injection.

Adenoidectomy↗
PubMed1997

Comparison of dobutamine ECG stress test with predischarge exercise test after acute myocardial infarction.

Exercise testing after acute myocardial infarction is commonly used, but in recent years alternative methods have been proposed. Standard exercise testing was compared with dobutamine electrocardiographic (ECG) stress testing in 100 patients after an acute initial myocardial infarction. Dobutamine ECG stress testing was performed in a standard manner at 5 +/- 1 days after the infarction and exercise testing was performed a mean of 10 +/- 2 days following the event. Agreement between both tests was observed in 91 cases (91%), P < .001, Fisher test kappa value, 0.79). The dobutamine test predicted the result of the exercise test with a sensitivity of 100% (95% confidence interval, 87-100) and a specificity of 88% (95% confidence interval 77-93) for a positive predictive value of 75% (95% confidence interval, 62-97) and a negative predictive value of 100% (95% confidence interval, 91-100). Dobutamine ECG stress testing is concluded to be an objective and reliable procedure, which accurately predicts the results of standard exercise testing. It is inexpensive, easy to perform, and although not yet confirmed, could be particularly useful in patients who cannot perform exercise.

Aged↗
PubMed1997

Anaesthesia for insertion of ear tubes in children: comparison of propofol, thiopentone and halothane.

To determine the quality of anaesthesia and speed of recovery after propofol anaesthesia for myringotomy in children, 100 children 2-12 years were randomized to one of four anaesthetic regimens for induction/maintenance: thiopentone (STP) (5 mg.kg-1)/halothane, propofol (3 mg.kg-1)/halothane, halothane/halothane or propofol (3 mg.kg-1)/propofol bolus (0.5 mg.kg-1 every 3 min (10 mg.kg-1.h-1)). Nitrous oxide (70%) in oxygen (30%) was used to facilitate insertion of an intravenous catheter and was continued throughout the anaesthetic. We found that the incidence of intraoperative movement in response to surgical stimulation was significantly greater in the prop/prop group 32%, compared with the three other groups (P < 0.02). Although some recovery variables (time to response to questions, sit unaided, tolerate oral fluids, and discharge with fluids) were achieved more rapidly by the prop/ prop group than the other three groups, the times to open eyes, obey commands and, most importantly, discharge from recovery without fluids did not differ between the prop/prop and the hal/ hal groups. We conclude that there is little benefit in using propofol as an induction agent alone or in combination with a propofol maintenance anaesthetic for paediatric myringotomy and tube surgery.

Anesthesia Recovery Period↗
PubMed1997

Parental perceptions, expectations and preferences for the postanaesthetic recovery of children.

Improvements in anaesthesia have led to the introduction of rapid-acting agents which quicken recovery and decrease sleepiness. Whether parents believe a rapid postanaesthetic recovery is an advantage is unknown. Therefore, we evaluated the parental perceptions, expectations and preferences for the postanaesthetic recovery of children. One hundred and three parents of children having ambulatory surgery completed a structured questionnaire and the results of 101 are presented. Results indicate that 93% of parents expect their child to be sleepy after surgery. Seventy-four per cent of parents indicated they would prefer their child to be sleepy or tired in the first 24 h postoperatively. Eight-five percent of parents would not be upset if their child's discharge was delayed up to three hours because their child was too sleepy. Finally 45.5% of parents are extremely concerned about their child experiencing postoperative pain and 68% believe that their child would be in more pain if they recovered rapidly from the anaesthetic. These results indicate that rapid recovery from anaesthesia and quick discharge from hospital are not key expectations of parents of children admitted for day surgery. Parents associate a rapid recovery with more pain. Parents need to be more fully informed of the advantages of a rapid recovery and reassured that children can recover quickly and completely but at the same time be comfortable postanaesthetic.

Ambulatory Surgical Procedures↗
PubMed1997

A randomized multicenter study of remifentanil compared with alfentanil, isoflurane, or propofol in anesthetized pediatric patients undergoing elective strabismus surgery.

Remifentanil hydrochloride is a new, ultrashort-acting opioid metabolized by nonspecific plasma and tissue esterases. We conducted this multicenter study to examine the hemodynamic response and recovery profile of premedicated children undergoing strabismus repair who were randomly assigned to receive one of four treatment drugs (remifentanil, alfentanil, isoflurane, or propofol) along with nitrous oxide and oxygen for maintenance of anesthesia. Induction of anesthesia was by nitrous oxide, oxygen, and halothane or nitrous oxide, oxygen, and propofol. Anesthesia was then maintained with remifentanil 1.0 microgram/kg over 30-60 s, followed by a constant infusion of 1.0 microgram.kg-1.min-1, alfentanil 100 micrograms/kg bolus followed by a constant infusion of 2.5 micrograms.kg-1.min-1, propofol 2.5 mg/kg bolus followed by a constant infusion of 200 micrograms.kg-1.min-1, or isoflurane 1.0 minimum alveolar anesthetic concentration. The infusions of the anesthetics and the administration of the inhaled gases were adjusted clinically by predetermined protocols. Elapsed time intervals from the end of surgery to the time the patients were tracheally extubated and displayed purposeful movement, as well as the time the patients met the postanesthesia care unit (PACU) and hospital discharge times, were recorded. Heart rate and systolic and diastolic blood pressure were measured at fixed intervals. In addition, cardiovascular side effects (bradycardia, hypotension, and hypertension) as well as vomiting, pruritus, agitation, and postoperative hypoxemia were also noted. There were no significant differences in patient demographics among the treatment groups. There was no difference in the early recovery variables (times to extubation and purposeful movement) or the times to PACU and hospital discharge among groups. There were significant differences in side effects among the groups. Patients who received remifentanil had higher PACU objective pain-discomfort scores than those who received alfentanil and propofol. Patients anesthetized with alfentanil had a greater incidence in the use of naloxone and a greater incidence of postoperative hypoxemia compared with those anesthetized with remifentanil. The incidence of postoperative hypoxemia was the same for remifentanil, propofol, and isoflurane groups. There were no significant differences in the incidence of emesis among the four groups, and all four groups had similar hemodynamic profiles. We conclude that remifentanil appears to be an effective drug for anesthesia. Its hemodynamic and recovery profile appear similar to other comparable drugs. Based on previous pharmacokinetic studies, the 1.0 microgram.kg-1.min-1 infusion may be twice the 50% effective dose observed in adults. In this study, the relative "overdose" of remifentanil was well tolerated and did not prolong recovery.

Alfentanil↗
PubMed1996

Study design in clinical research: sample size estimation and power analysis.

The purpose of this review is to describe the statistical methods available to determine sample size and power analysis in clinical trials. The information was obtained from standard textbooks and personal experience. Equations are provided for the calculations and suggestions are made for the use of power tables. It is concluded that sample size calculations and power analysis can be performed with the information provided and that the validity of clinical investigation would be improved by greater use of such analyses.

Clinical Trials as Topic↗
PubMed1996

Pharmacokinetics of the active metabolite (MDL 74,156) of dolasetron mesylate after oral or intravenous administration to anesthetized children.

BACKGROUND: Dolasetron mesylate is a selective 5-HT3 receptor antagonist under investigation as an antiemetic in children. Published studies indicate that its antiemetic activity results from the active metabolite (MDL 74,156), which is produced within 10 minutes of administration of dolasetron mesylate. METHODS: The pharmacokinetics of MDL 74,156 and the safety and tolerability of dolasetron mesylate were studied after a single oral or intravenous dose of 1.2 mg.kg-1 dolasetron mesylate to healthy children from 2 to 12 years of age. Oral dolasetron was administered to 12 children 1 to 2 hours before anesthesia. Intravenous dolasteron was administered to 18 children at induction of anesthesia. Serial blood samples were collected for 24 hours after dosing to measure the plasma concentration of MDL 74,156. Indexes of liver and kidney function were determined, and electrocardiograms and adverse events were recorded.

Administration, Oral↗
PubMed1996

Dimenhydrinate decreases vomiting after strabismus surgery in children.

Dimenhydrinate, an H1-receptor antagonist, has been used to both prevent and treat postoperative vomiting (POV) in children for several decades. However, its effectiveness for POV after strabismus surgery remains anecdotal. This study was designed to determine the effectiveness and side effects of dimenhydrinate for the prevention of POV in children after strabismus surgery. Eighty ASA physical status I or II children, ages 1-12 yr inclusive, who were undergoing strabismus surgery, were prospectively and randomly allocated to receive either dimenhydrinate 0.5 mg/kg intravenously (n = 40) or placebo (n = 40) at induction of anesthesia. The incidence of POV and the times to arousal (and discharge from the recovery room and hospital) were recorded postoperatively in a double blinded manner. For 24 h after discharge from the hospital, all emetic episodes and medications given were recorded by the parents. Demographic data did not differ between the groups. Children who received dimenhydrinate had significantly less POV both inhospital (10%) and overall (30%) than those who received placebo (in-hospital 38%, P < 0.008; overall 65%, P < 0.003). The times to arousal and discharge from the hospital did not differ between the two groups. Dimenhydrinate (0.5 mg/kg) is an effective, safe, and inexpensive antiemetic in children undergoing strabismus surgery. It significantly reduces the incidence of vomiting for 24 h postoperatively and is not associated with prolonged sedation or other adverse effects.

Antiemetics↗
PubMed1996

Plasma inorganic fluoride concentrations after sevoflurane anesthesia in children.

BACKGROUND: Sevoflurane is degraded in vivo in adults yielding plasma concentrations of inorganic fluoride [F-] that, in some patients, approach or exceed the 50- micron theoretical threshold for nephrotoxicity. To determine whether the plasma concentration of inorganic fluoride [F-] after 1-5 MAC x h sevoflurane approaches a similar concentration in children, the following study in 120 children scheduled for elective surgery was undertaken. METHODS: Children were randomly assigned to one of three treatment groups before induction of anesthesia: group 1 received sevoflurane in air/oxygen 30% (n = 40), group 2 received sevoflurane in 70% N2O/30% O2 (n = 40), and group 3 received halothane in 70% N2O/30% O2 (n = 40). Mapleson D or F circuits with fresh gas flows between 3 and 61/min were used Whole blood was collected at induction and termination of anesthesia and at 1, 4, 6, 12, and 18 or 24 h postoperatively for determination of the [F-]. Plasma urea and creatinine concentrations were determined at induction of anesthesia and 18 or 24 h postoperatively. RESULTS: The mean (+/- SD) duration of sevoflurane anesthesia, 2.7 +/- 1.6 MAC x h (range 1.1-8.9 MAC x h), was similar to that of halothane, 2.5 +/- 1.1 MAC x h. The peak [F-] after sevoflurane was recorded at 1 h after termination of the anesthetic in all but three children (whose peak values were recorded between 4 and 6 h postanesthesia). The mean peak [F-] after sevoflurane was 15.8 +/- 4.6 microns. The [F-] decreased to <6.2 microns b 24 h postanesthesia. Both the peak [F-] (r2 = 0.50) and the area under the plasma concentration of inorganic fluoride-time curve (r2 = 0.57) increased in parallel with the MAC x h of sevoflurane. The peak [F-] after halothane, 2.0 +/- 1.2 microns, was significantly less than that after sevoflurane (P<0.00012) and did not correlate with the duration of halothane anesthesia (MAC x h; r2 = 0.007). Plasma urea concentrations decreased 24 h after surgery compared with preoperative values for both anesthetics (P<0.01), whereas plasma creatinine concentrations did not change significantly with either anesthetic. CONCLUSIONS: It was concluded that, during the 24 h after 2.7 +/- 1.6 MAC x h sevoflurane, the peak recorded [F-] is low (15.8 microns), F- is eliminated rapidly, and children are unlikely to be at risk of nephrotoxicity from high [F-].

Anesthetics, Inhalation↗
PubMed1996

Induction, recovery, and safety characteristics of sevoflurane in children undergoing ambulatory surgery. A comparison with halothane.

BACKGROUND: Sevoflurane is an inhalational anesthetic with characteristics suited for use in children. To determine whether the induction, recovery, and safety characteristics of sevoflurane differ from those of halothane, the following open-labeled, multicenter, randomized, controlled, phase III study in children undergoing ambulatory surgery was designed. METHODS: Three hundred seventy-five children, ASA physical status 1 or 2, were randomly assigned in a 2:1 ratio to receive either sevoflurance or halothane, both in 60% N2O and 40% O2. Anesthesia was induced using a mask with an Ayre's t piece or Bain circuit in four of the centers and a mask with a circle circuit in the fifth center. Maximum inspired concentrations during induction of anesthesia were 7% sevoflurane and 4.3% halothane. Anesthesia was maintained by spontaneous ventilation, without tracheal intubation. End-tidal concentrations of both inhalational anesthetics were adjusted to 1.0 MAC for at least 10 min before the end of surgery. Induction and recovery characteristics and all side effects were recorded. The plasma concentration of inorganic fluoride was measured at induction of and 1 h after anesthesia. RESULTS: During induction of anesthesia, the time to loss of the eyelash reflex with sevoflurane was 0.3 min faster than with halothane (P < 0.001). The incidence of airway reflex responses was similar, albeit infrequent with both anesthetics. The total MAC.h exposure to sevoflurane was 11% less than the exposure to halothane (P < 0.013), although the end-tidal MAC multiple during the final 10 min of anesthesia was similar for both groups. Early recovery as evidenced by the time to response to commands after sevoflurane was 33% more rapid than it was after halothane (P < 0.001), although the time to discharge from hospital was similar for both anesthetics. The mean ( +/- SD) plasma concentration of inorganic fluoride 1 h after discontinuation of sevoflurane was 10.3 +/- 3.5 microM. The overall incidence of adverse events attributable to sevoflurane was similar to that of halothane, although the incidence of agitation attributable to sevoflurane was almost threefold greater than that attributable to halothane (P < 0.004). CONCLUSIONS: Sevoflurane compared favorably with halothane. Early recovery after sevoflurane was predictably more rapid than after halothane, although this was not reflected in a more rapid discharge from the hospital. The incidence of adverse events was similar for both anesthetics. Clinically, the induction, recovery, and safety characteristics of sevoflurane and halothane are similar. Sevoflurane is a suitable alternative to halothane for use in children undergoing minor ambulatory surgery.

Ambulatory Surgical Procedures↗
PubMed1996

Acute lung injury after instillation of human breast milk or infant formula into rabbits' lungs.

BACKGROUND: Recent interest in shortening the fasting interval after ingestion of milk products demonstrated large volumes of breast milk in the stomach 2 h after breastfeeding. Although aspiration is a rare event, if it were to occur with human breast milk, it is important to understand the extent of the lung injury that might occur. Therefore, the response to instillation of acidified breast milk and infant formula in the lungs of adult rabbits was studied. METHODS: In 18 anesthetized adult rabbits, 1 of 3 fluids (in a volume of 0.8 ml.kg-1 and pH level of 1.8, acidified with hydrochloric acid); saline, breast milk, or infant formula (SMA, Wyeth, Windsor, Ontario), was instilled into the lungs via a tracheotomy. The lungs were ventilated for 4 h after instillation. Alveolar-to-arterial oxygen gradient and dynamic compliance were measured before and at hourly intervals after instillation. After 4 h, the rabbits were killed and the lungs were excised. Neutrophil infiltration was quantitated by a pathologist blinded to the instilled fluid. A histologic control group of four rabbits was ventilated under study conditions without any intratracheal fluid instillation. RESULTS: Alveolar-to-arterial oxygen gradient increased and dynamic compliance decreased significantly during the 4 h after instillation of both breast milk and infant formula compared with baseline measurements and with saline controls (P < 0.05). The neutrophil counts in the lungs from the saline, breast milk, and formula rabbits were significantly greater than those in the control group. CONCLUSIONS: Instillation of acidified breast milk or infant formula (in a volume of 0.8 ml.kg-1 and pH level of 1.8) into rabbits' lungs induces acute lung injury of similar intensity that lasts at least 4 h.

Acute Disease↗