Biomedical subjects

A Michalek-Sauberer

Publications and source records attributed to A Michalek-Sauberer.

10 recordsLinked to original sources

PubMed2002

Sevoflurane and propofol decrease intraocular pressure equally during non-ophthalmic surgery and recovery.

BACKGROUND: To provide good control of intraocular pressure (IOP) during anaesthesia and surgery, we conducted a study comparing the effects on IOP during maintenance and recovery of sevoflurane vs propofol anaesthesia in 33 patients (ASA I-II) undergoing elective non- ophthalmic surgery. METHODS: Anaesthesia was induced with propofol 2 mg kg(-1), fentanyl 2 micro g kg(-1) and vecuronium 0.1 mg kg(-1). Patients were allocated randomly to receive either propofol 4-8 mg kg(-1) h(-1) (group P; n=16) or 1.5-2.5 vol% sevoflurane (group S; n=17) for maintenance of anaesthesia. Fentanyl 2-4 micro g kg(-1) was added if necessary. The lungs were ventilated with 50% air in oxygen. Blood pressure, heart rate, oxygen saturation and end-tidal carbon dioxide were measured before and throughout anaesthesia and in the recovery room. IOP was determined with applanation tonometry (Perkins) by one ophthalmologist blinded to the anaesthetic technique. RESULTS: There was a significant decrease in IOP after induction and during maintenance of anaesthesia in both groups. No significant differences in IOP between the two groups was found. CONCLUSION: Sevoflurane maintains the IOP at an equally reduced level compared with propofol.

Adolescent↗

PubMed2000

Effects of vecuronium and rocuronium in antagonistic laryngeal muscles and the anterior tibial muscle in the cat.

BACKGROUND: Adequate vocal cord paralysis and full recovery of laryngeal muscle function are important when muscle relaxants are used perioperatively. This study was designed to compare the effects of vecuronium and rocuronium at the vocal cord abductor and adductor muscles and the anterior tibial muscle in cats. METHODS: Twelve adult cats were studied under pentobarbitone-N2O/O2-anesthesia. After supramaximal electrical stimulation of the peroneal nerve and the recurrent laryngeal nerve (0.1 Hz and intermittent train-of-four) evoked electromyographic responses were obtained from the anterior tibial muscle, the posterior cricoarytenoid muscle (vocal cord abductor) and two vocal cord adductor muscles, the lateral cricoarytenoid and the vocal muscle. Six cats received bolus doses of increasing size of vecuronium (ED90 22.5 microg x kg(-1)) and six cats rocuronium (ED90 90 microg x kg(-1)). RESULTS: Equipotent doses of vecuronium and rocuronium caused a similar degree of paralysis in all muscles (vecuronium ED90: 70% blockade at the posterior cricoarytenoid, 83% at the lateral cricoarytenoid, 84% at the vocal muscle and 90% at the anterior tibial muscle; rocuronium ED90: 71% at the posterior cricoarytenoid, 67% at the lateral cricoarytenoid, 78% at the vocal muscle and 90% at the anterior tibial muscle; vecuronium 2 x ED90: 93% blockade at the posterior cricoarytenoid, 95% at the lateral cricoarytenoid, 97% at the vocal muscle and 99% at the anterior tibial muscle; rocuronium 2 x ED90: 89% blockade at the posterior and lateral cricoarytenoid, 93% at the vocal muscle and 100% at the anterior tibial muscle). Onset time was significantly shorter at the posterior cricoarytenoid muscle (290 s) compared to the lateral cricoarytenoid muscle (400 s) after vecuronium ED90 and to the vocal muscle (150 s versus 210 s) after rocuronium ED90. Compared to the anterior tibial muscle (interval 25-75%: 6.5 min after vecuronium 2 x ED90 and 3.3 min after rocuronium 2 x ED90 and to the posterior cricoarytenoid muscle (interval 25-75%: 7 min after vecuronium 2 x ED90 and 4.3 min after rocuronium 2 x ED90), recovery of laryngeal adductor muscle function was markedly delayed with both neuromuscular blocking drugs (interval 25-75% at the lateral cricoarytenoid and vocal muscle: 14 min and 15.8 min after vecuronium 2 x ED90 and 10.3 min and 11.6 min after rocuronium 2 x ED90 respectively). CONCLUSION: In cats, the time course of neuromuscular blockade after vecuronium and rocuronium differs in antagonistic laryngeal muscles. The protective laryngeal function of glottis closure recovers later than vocal cord abduction after both vecuronium and rocuronium.

Androstanols↗

PubMed1998

Sevoflurane anaesthesia in paediatric patients: better than halothane?

Forty-two children (aged 2-16 years) were randomly assigned to receive either sevoflurane (n = 21) or halothane (n = 21) in nitrous oxide/oxygen. After pre-medication with midazolam, anaesthesia was induced by facemask and the anaesthetic concentration was increased until loss of eyelash reflex (sevoflurane, 6%; halothane, 2.5%). Thereafter, 1-1.5 MAC of the inhalational agents were maintained until skin closure. Intra-operative analgesia was provided either by intermittent intravenous (i.v.) bolus doses of fentanyl (2-3 micrograms kg-1) or by a regional blockade. Induction was smooth and the time to loss of eyelash reflex was slightly shorter with sevoflurane than with halothane, the difference not quite reaching statistical significance (P = 0.06). In both groups, heart rate remained stable and blood pressure decreased significantly during induction. Haemodynamic parameters remained stable during anaesthetic maintenance; no cardiac dysrhythmias were observed. Emergence time with sevoflurane was 12.9 min vs. 16.3 min with halothane, but this difference was not statistically significant. It is concluded that sevoflurane is as suitable for paediatric patients as halothane. The slightly faster emergence time offered by sevoflurane over halothane was of no clinical significance in the present study.

Adolescent↗

PubMed1998

The efficacy and safety of a clonidine/bupivacaine combination in caudal blockade for pediatric hernia repair.

UNLABELLED: We evaluated the analgesic efficacy and hemodynamic and respiratory safety of clonidine when added to bupivacaine for caudal blocks in 58 children aged 38 +/- 2 mo (mean +/- SEM). Patients scheduled for ambulatory hernia repair were randomly given a caudal injection (0.75 mL/kg) of either saline placebo (P group), bupivacaine, 0.25% (B group), bupivacaine plus epinephrine 1:200,000 (BE group), bupivacaine plus clonidine 1 microgram/kg (BC1 group), or bupivacaine plus clonidine 2 micrograms/kg (BC2 group). Postoperative measurements included duration of analgesia, hemodynamics, and respiratory monitoring for 6 h. Thereafter, parents assessed their child's analgesic requirements at home every 3 h for 18 h. The duration of analgesia (median [range]) was significantly longer (P < 0.05) in the BC1 and BC2 groups (360 [270-360] min and 360 [355-360] min, respectively) compared with the P (77[45-190]), B (346[105-360]), or BE group (300[75-360]). Similarly, the BC1 and BC2 groups required less additional analgesic within the first 24 h. All groups showed a significant decrease in mean arterial pressure compared with baseline values, but the differences among the groups were not significant. Bradycardia and respiratory depression were not observed. Clonidine 1 and 2 micrograms/kg can be safely added to bupivacaine caudal blockade in small children for ambulatory hernia repair to achieve an increased duration of analgesia compared with bupivacaine alone or bupivacaine plus epinephrine. IMPLICATIONS: The addition of clonidine, an antihypertensive drug with analgesic properties, to local anesthetics in caudal blocks prolongs postoperative pain relief and reduces the need for additional pain treatment in children after hernia operation.

Analgesics, Non-Narcotic↗

PubMed1998

The cerebral and cardiovascular effects of cisatracurium and atracurium in neurosurgical patients.

UNLABELLED: Drugs for neurosurgical patients should not increase intracranial pressure (ICP) or change cerebral perfusion pressure (CPP) and cerebral blood flow. This double-blind, cross-over study compares the effects of a single (3 x effective dose producing 95% twitch depression) intravenous bolus dose of cisatracurium 0.15 mg/kg with atracurium 0.75 mg/kg on mean red blood cell flow velocity in the middle cerebral artery (CBFV; transcranial Doppler), ICP (intraventricular or intraparenchymal monitor), mean arterial pressure (MAP), CPP (MAP-ICP), and heart rate (HR) every minute during a 15-min study period. Included in the study were 14 sedated and ventilated adult neurosurgical patients. After the cisatracurium bolus, ICP, CPP, CBFV, MAP, and HR did not change, and no histamine related events were observed. After the atracurium bolus, ICP, CPP, CBFV, and MAP decreased. The lowest values of ICP (-16% of baseline), CPP (-5%), CBFV (-8%), and MAP (-7%) were recorded 2-4 min after the atracurium bolus injection. After this transient decrease, MAP and CPP returned to baseline, whereas CBFV and ICP transiently exceeded baseline values. The highest values of CBFV (5%) and ICP (17%) were recorded 9-12 min after the atracurium bolus injection. Five patients showed a typical histamine response after atracurium, with a decrease in MAP and flushing. Excluding these five patients eliminated statistical significance in ICP, CPP, CBFV, and MAP differences. In conclusion, cisatracurium demonstrated fewer cerebral and cardiovascular hemodynamic side effects in sedated adult neurosurgical patients. IMPLICATIONS: This double-blind study in sedated and mechanically ventilated adult neurosurgical patients demonstrates that an intravenous bolus dose of the neuromuscular blocker cisatracurium results in less cerebral (intracranial pressure, cerebral perfusion pressure, middle cerebral artery blood flow velocity) and cardiovascular (blood pressure) hemodynamic side effects, compared with an equipotent dose of atracurium.

Adult↗

PubMed1998