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Biomedical subjects

W Wilhelm

Publications and source records attributed to W Wilhelm.

At least 55 records · Page 3Linked to original sources
PubMed1999

[The use of remifentanil in critically ill patients. Clinical findings and early experience].

OBJECTIVES: It was the aim of this investigation to report our initial clinical experience on the use of remifentanil in critically ill patients undergoing mechanical ventilation. Additionally, we hypothesized that even under intensive care conditions remifentanil might facilitate a temporally predictable and "programmed" tracheal extubation. METHODS: Remifentanil was used for analgesia and sedation of mechanically ventilated patients who were admitted to the ICU following major noncardiac surgery or who had to be ventilated due to respiratory failure. The infusion was started with 0.15 microg/kg/min and then adapted in steps of 0.05 microg/kg/min according to clinical needs. After admission to the ICU the depth of sedation was adjusted to a Ramsay score level of 4 (sleeping patient, immediately arousable) and then targeted at a level of 2-3 (patient awake, co-operative and tranquil or responding to command only). In case of sufficient pain relief but inadequate sedation patients could receive bolus doses of midazolam (1-3 mg) or an infusion of clonidine (0.5 microg/kg/h), the latter especially in case of shivering or hypertension. Prior to extubation bolus doses of piritramide (3-5 mg) and a non-opioid analgesic (metamizol or propacetamol) could be used for postoperative pain relief. Data are presented as mean+/-SD. RESULTS: A total of 46 patients were studied, aged 62.8+/-15.4 yr with a mean APACHE II score of 19.2 points. The duration of remifentanil infusion ranged up to 78 h with a mean of 9. 8 h. The mean infusion rate was 0.14+/-0.08 microg/kg/min during ongoing analgesia and sedation and 0.10+/-0.08 microg/kg/min immediately before its discontinuance. Additional sedatives were necessary in 63% of all patients. Emergence was rapid in the majority of cases: 67% of all patients could safely be extubated within 15 min after termination of remifentanil, and a total of 87% were extubated within 45 min. A development of tolerance was not observed during the study period. CONCLUSIONS: Remifentanil appeared to be suitable for analgesia and sedation of critically ill patients undergoing mechanical ventilation: Even under intensive care conditions recovery was rapid in the majority of cases, and in two thirds of all patients tracheal extubation was temporally predictable and could be timed within 15 min. These results are best explained by the metabolism and offset of action of remifentanil obviously unaffected in the ICU area. However, for fast emergence the cautious use of additional sedatives is crucial.

APACHE↗
PubMed1999

[Remifentanil for oocyte retrieval: A new single-agent monitored anaesthesia care technique].

INTRODUCTION: Transvaginal puncture for oocyte retrieval is a short-lasting but painful procedure. We hypothesized that a sole infusion of the ultra-short acting mu-agonist remifentanil may be a suitable and well-controllable single-agent analgesic technique that can dose-dependently be applied to spontaneously breathing patients. METHODS: Fifty consenting adult women were enrolled in this prospective trial. A sedative premedication was omitted, all patients received 3 L/min of inhaled oxygen, and a sole remifentanil infusion was started with 0.25 microg/kg/min. Remifentanil was adjusted as needed for pain relief (in steps of 0.05 microg/kg/min) and finished after the last puncture. Dosage requirements, vital functions, oxygen saturation (as achieved by pulse oximetry, psO(2)), adverse drug effects and the level of sedation (LOS 1-5; 1 = asleep/unarousable, 4 = calm/awake) were recorded. Remifentanil plasma concentrations were achieved by STANPUMP pharmacokinetic simulation. Data are presented as mean +/- SD. RESULTS: A total of 50 women (31.8 +/- 5.1 yr, 67.3 +/- 14. ASA I or II ) were investigated. Follicular aspiration lasted 10.8+/-5.2 min, and remifentanil was infused for 19.7+/-8.3 min. Dosage requirements were 0.25 microg/kg/min in 70% of all patients, 0.3 microg/kg/min in 22%, 0.2 microg/kg/min in 6%, and 0.4 microg/kg/min in 2% of all cases. Vital signs (baseline, after 1(st) puncture, end of surgery) nearly remained unchanged: heart frequency = 85 +/- 15, 87 +/- 17, 90 +/- 17 bpm, systolic blood pressure = 129 +/- 12, 132 +/- 13, 131 +/- 14 mmHg; respiratory rate = 116 +/- 4, 15 +/- 4 breaths/min; psO(2) = 99 +/- 1, 99 +/- 1, 99 +/- 2%. LOS was 4.0 (all), 3.9 +/- 0.3, 3.9 +/- 0.3. Remifentanil plasma concentrations were 5.0 +/- 1.3 ng/mL at the start, 6.6 +/- 1.3 at the end of surgery and 1.2 +/- 0.5 at PACU arrival. Adverse drug effects: 54% itching, no muscle rigidity. 94% of all women would choose this technique again. CONCLUSIONS: The sole infusion of remifentanil is a suitable and satisfying single-agent monitored anaesthesia care technique for oocyte retrieval. However, close anaesthetic observation - especially of the respiratory function - is mandatory.

Adult↗
PubMed1999

Effects of general anaesthesia vs. sedation on fertilization, cleavage and pregnancy rates in an IVF program.

Anaesthetic management for oocyte retrieval may interfere with the results and success rate of an in vitro fertilization (IVF) program. This study was conducted to compare the effects of two different anaesthetic techniques (general anaesthesia versus sedation) used for oocyte retrieval on IVF outcome. For general anaesthesia we used a combination of remifentanil (Ultiva) with either propofol or isoflurane in hypnotic concentrations. For sedation the protocol included midazolam, diazepam or propofol according to clinical needs. In total, 202 women were enrolled in the study. 96 women opted for sedation and 106 for general anaesthesia. The number of collected oocytes was significantly higher with general anaesthesia (10.54+/-5.43 [mean+/-SD]) than with sedation (6.25+/-3.65, p<0.0001), whereas the number of fertilized oocytes was not different (4.70+/-3.57 vs. 4.23+/-2.90). There were no significant differences in cleavage and pregnancy rates. We therefore believe that remifentanil-based general anaesthesia without nitrous oxide is a suitable alternative to sedation and may be recommended for IVF oocyte retrieval if general anaesthesia is requested.

Anesthesia, General↗
PubMed1999

[Portable capnographs in emergency care: a comparison of equipment].

Recently, transportable capnographs fulfilling the practical demands of emergency medicine have become commercially available (NPB-75, sidestream, Nellcor Puritan Bennett; and Tidal Wave, mainstream, Novametrix). A prerequisite for their use is an accuracy as required for clinical purposes (i.e., pCO2 +/- 2 mmHg). Additionally, environmental conditions in emergency medicine (e.g., changes in ambient temperature) should not have a significant impact on accuracy. The objective of this investigation was to analyse the accuracy of the two capnographs. The accuracy of the pCO2 measurement was evaluated under the following conditions: (1) measurement with three gas mixtures of defined concentrations (gas A: 5% CO2, 95% O2; gas B: 5% CO2, 20% O2, 75% N2; gas C: 10% CO2, 90% N2) related to STPD conditions (STPD = Standard Temperature and Pressure, Dry); and (2) exposure to changes in temperature (from +22 degrees C to -20 degrees C, and from -20 degrees C to +22 degrees C) applying the aforementioned 3 gas mixtures (STPD); and (3) in 20 patients manually ventilated with pure oxygen following endotracheal intubation (i.e., BTPS conditions = body temperature and pressure, saturated). Adequacy of the results was compared to the alveolar gas monitor AGM 1304 (Bruel & Kjaer, Copenhagen, Denmark; sidestream) which served as the reference method (providing an accuracy for the alveolar carbon dioxide partial pressure (pACO2) of +/- 1 mmHg). In the 3 dry gas mixtures, mean inaccuracy proved to be +4.5 +/- 4.1, +2.8 +/- 3.7, and +2.2 +/- 7.0 mmHg (gas A, gas B, gas C; STPD) with the Nellcor sidestream device. Using the Novametrix mainstream capnograph the results were found as follows: (1) -1.1 +/- 0.6, +2.9 +/- 0.6, and +5.6 +/- 2.3 mmHg (oxygen compensation enabled); and (2) +0.2 +/- 1.6, +2.2 +/- 0.6, and +3.2 +/- 4.2 mmHg (oxygen compensation disabled). After changing the environmental temperature (-20 degrees C / +22 degrees C), the resulting deviations (gases A-C, STPD) found with the Nellcor device averaged -12 +/- 4% and +15 +/- 3% (Nellcor); with the Novametrix mainstream device the deviations averaged -1 +/- 2% and +1 +/- 1%, and -2 +/- 1% and +1 +/- 1% (oxygen compensation enabled/disabled). Mean inaccuracy of the pCO2 measurement during ventilation of patients with pure oxygen (BTPS) was found to average -0.9 +/- 0.9 (Nellcor), and either +3.9 +/- 0.8 or +2.1 +/- 0.7 mmHg with the Novametrix (oxygen compensation enabled/disabled). Under BTPS conditions, both devices showed an acceptable deviation of the measurement accuracy up to a maximum of +/- 2 mmHg. The higher deviations of the "NPB-75" (Nellcor Puritan Bennett, sidestream) when using dry gas mixtures (STPD) may be explained by the automatic water vapour correction. Under the conditions of low and changing ambient temperature (-20 degrees C, +22 degrees C), only the "Tidal Wave" (Novametrix; mainstream) remained uninfluenced, whereas deviations of -12% and +15% were found with the "NPB-75".

Capnography↗
PubMed1998

[Ondansetron. Prophylaxis and therapy of nausea and vomiting following major gynecologic procedures. Results of a national multicenter study].

UNLABELLED: This investigation was conducted as a national multicenter study to evaluate effectiveness and safety of prophylactic and therapeutic ondansetron for postoperative nausea and vomiting (PONV) in major gynaecological surgery. METHODS: 387 patients were randomised to receive either ondansetron 8 mg or placebo i.v. prior to anaesthesia induction. Anaesthesia was performed with a volatile anaesthetic, nitrous oxide and opioids. Established PONV was treated with ondansetron 4 mg i.v. Postoperative evaluation included time, duration and severeness of nausea and vomiting in the first 24 h after the operation. RESULTS: In the study period the incidence of emesis was 35% after prophylactic ondansetron and 58% after placebo (p < 0.01). Nausea occurred in 49% and 64% respectively (p < 0.01). 28% after prophylactic ondansetron and 48% after placebo required ondansetron therapy (p < 0.01). The number of adverse events was small in total and comparable for both groups. CONCLUSION: Our investigation proves the efficiency of ondansetron 8 mg prior to induction of anaesthesia in preventing PONV. Furthermore, our results demonstrate the safety of the drug for prophylaxis and therapy.

Antiemetics↗
PubMed1998

Desflurane or isoflurane for paediatric ENT anaesthesia. A comparison of intubating conditions and recovery profile.

BACKGROUND: The inhaled anaesthetic desflurane is characterized by a rapid wash-in and wash-out and may be useful for short paediatric ENT procedures. Therefore, this study was designed to compare the effects of desflurane or isoflurane on intubating conditions and recovery characteristics in paediatric ENT patients. METHODS: In this prospective, randomised investigation, we studied 44 children scheduled for ENT surgery, aged 4-12 yr and classified ASA I-II. After thiopentone induction (5-8 mg/kg) the lungs were ventilated by face mask and the vaporizer was dialed to 1 MAC (age-adapted) of desflurane of isoflurane. A reduced dose of vecuronium (0.05 mg/kg) was administered, and intubating conditions were rated 3 min later. Following tracheal intubation, 50% nitrous oxide were added, and the concentration of desflurane or isoflurane was adjusted according to clinical needs. At the end of surgery all anaesthetics were discontinued simultaneously and recovery times were recorded. RESULTS: Intubating conditions were rated significantly better for desflurane (excellent or good 20 of 22) than for isoflurane (12 of 22). Recovery times were significantly shorter for desflurane than for isoflurane (mean +/- SE): spontaneous ventilation 4.0 +/- 0.5 min vs. 6.0 +/- 0.7 min, extubation 8.4 +/- 0.7 vs. 11.4 +/- 1.1 min and arrival at PACU 11.5 +/- 0.8 vs. 16.6 +/- 1.5 min. No airway complications (coughing, laryngospasm, or desaturation < 97%) were noted for either anaesthetic. CONCLUSIONS: Following an intravenous induction improved intubating conditions, shorter recovery times and the lack of airway complications make desflurane a suitable alternative to isoflurane for paediatric ENT anaesthesia.

Anesthesia Recovery Period↗
PubMed1998

[Remifentanil in gynecologic laparoscopy. A comparison of consciousness and circulatory effects of a combination with desflurane and propofol].

OBJECTIVES: Rapid post-anaesthetic awakening and low hypnotic potency are two characteristic properties of the new opioid remifentanil. For clinical use remifentanil must be combined with another anaesthetic agent. Propofol is well-established for ambulatory anaesthesia, however, the properties of desflurane (low blood-gas solubility, rapid elimination) suggest this volatile anaesthetic to be a comparable alternative, particularly if rapid awakening is desired. The present study was designed to compare emergence times and haemodynamics for a combination of remifentanil wich hypnotic concentrations of either propofol or desflurane. METHODS: Gynaecological patients, scheduled for elective laparoscopy, were studied at random. After oral premedication with diazepam 0.08-0.12 mg/kg, anaesthesia was induced identically in both groups: remifentanil bolus (1 microgram/kg), start of remifentanil infusion (0.5 microgram/kg/min), followed by propofol (approx. 2 mg/kg) and cisatracurium (0.1 mg/kg). For maintenance of anaesthesia remifentanil (0.25 microgram/kg/min) was combined with either desflurane (0.5 MAC = 3.0 vol%) or propofol (6 mg/kg/h). With termination of surgery anaesthetic delivery was discontinued simultaneously and recovery times were recorded. Heart rate and non-invasive blood pressure were recorded at defined points of interest. RESULTS: In total, 40 patients (desflurane n = 20, propofol n = 20) were studied in comparable groups. For both regimens, emergence after remifentanil-based anaesthesia was remarkably rapid between unconsciousness and complete recovery: In mean only 60 s elapsed from the onset of spontaneous breathing to the moment when patients could clearly state their name. In comparison, recovery times were significantly shorter after remifentanil-desflurane than after remifentanil-propofol: time to spontaneous ventilation 6.4 +/- 2.8 vs. 9.6 +/- 3.9 min (mean +/- SD, p = 0.01); extubation 6.7 +/- 2.8 vs. 9.8 +/- 4.0 min (p = 0.02) and arrival at PACU 11.1 +/- 3.4 vs. 14.7 +/- 4.2 min (p = 0.005). The courses of heart rate (HR) and mean arterial pressure (MAP) were mostly similar in both groups with only minimal or moderate cardiocirculatory reactions during intubation or start of surgery. CONCLUSIONS: Remifentanil in combination with either desflurane or propofol, used for general anaesthesia during gynaecological laparoscopy, will facilitate a smooth haemodynamic course as well as a rapid emergence thereafter. Recovery times after remifentanil-based anaesthesia are significantly shorter with 3.0 vol% of desflurane than with 6 mg/kg/h propofol. Thus, desflurane appears to be a well-suited adjunct to remifentanil and an ideal alternative to propofol, if rapid recovery is required. Differences are best explained by the pharmacological properties of both coanaesthetics and their applied dosages.

Adult↗
PubMed1998

Effect of intravenous anesthetics on spontaneous and endotoxin-stimulated cytokine response in cultured human whole blood.

BACKGROUND: Various anesthetics have been suggested to interfere with the immune system. The ability of leukocytes to express surface receptors and mediators is fundamental to a successful host defense. Therefore, the effects of intravenous anesthetics on cytokine release by leukocytes and expression of surface molecules known to modulate this response were determined. METHODS: Concentration-dependent effects of thiopentone, etomidate, propofol, ketamine, midazolam, and fentanyl on spontaneous and endotoxin (lipopolysaccharide; 1 microg/ml)-stimulated cytokine release were studied in whole blood from volunteers (n = 6) cultured for 25 h. In addition, expression of the lipopolysaccharide-recognition molecule CD14 and the major histocompatibility complex class II molecule human leukocyte locus A system-DR (HLA-DR) on monocytes were assessed using flow cytometry. RESULTS: All anesthetics studied elicited only minor effects on spontaneous cytokine release even at pharmacologic concentrations. However, expression density of CD14 was reduced in the presence of thiopentone, etomidate, and propofol, whereas HLA-DR was unaffected. Lipopolysaccharide-stimulated tumor necrosis factor response was inhibited by thiopentone (12.8% [median]; 7.6-18.8 [25-75 percentile]) of control, and ketamine (46.4% [median]; 44.4-56.4 [25-75 percentile]), at pharmacologic concentrations, whereas it was augmented even in the presence of low concentrations of propofol (172.3% [median]; 120.5-200.7 [25-75 percentile]). Ketamine additionally decreased the concentration of interleukin (IL)-1beta (14.8% [median]; 12.0-18.0 [25-75 percentile]). Release of IL-1 receptor antagonist (IL-1ra) was inhibited by thiopentone, etomidate, and propofol, whereas the same anesthetics increased IL-10 concentration simultaneously. Midazolam and fentanyl did not alter the concentrations of any cytokine. CONCLUSIONS: These results suggest a complex modulation of the cytokine response by the studied anesthetics in cultured whole blood. Although effects on spontaneous cytokine release by leukocytes were negligible, some anesthetics affected their ability to respond to lipopolysaccharide.

Anesthetics, Intravenous↗
PubMed1998

Total intravenous anaesthesia with propofol and remifentanil in paediatric patients: a comparison with a desflurane-nitrous oxide inhalation anaesthesia.

BACKGROUND: Remifentanil is a new rapid-acting and ultra-short acting mu-opioid receptor agonist with few reports from use in children. Therefore, we compared a propofol-remifentanil-anaesthesia (TIVA) with a desflurane-N2O-anaesthesia (DN) with particular regard to the recovery of characteristics in children. METHODS: 50 children (4-11 yr) scheduled for ENT surgery were randomly assigned to receive TIVA (n = 25) or DN (N = 25). After standardised i.v. induction of anaesthesia in both groups with remifentanil, propofol and cisatracurium, TIVA was maintained with infusion of propofol and remifentanil. Ventilation was with oxygen in air. DN was maintained with desflurane in 50% N20. The administration of volatile and intravenous anaesthetics was adjusted to maintain a surgical plane of anaesthesia. At the end of surgery all anaesthetics were terminated without tapering and early emergence and recovery were assessed. In addition, side effects were noted. RESULTS: Both anaesthesia methods resulted in stable haemodynamics but significantly higher heart rate with desflurane. Recovery did not differ between the groups except for delayed spontaneous respiration after TIVA. Spontaneous ventilation occurred after 11 +/- 03.7 min versus 7.2 +/- 2.8 min (mean +/- SD, TIVA versus DN), extubation after 11 +/- 3.7 min versus 9.4 +/- 2.9 min, eye opening after 11 +/- 3.9 min versus 14 +/- 7.6 min and Aldrete score > or = 9 after 17 +/- 6.8 min versus 17 +/- 7.5 min. Postoperatively, there was a significant higher incidence of agitation in the DN group (80% vs. 44%) but a low incidence (< 10%) of nausea and vomiting in both groups. CONCLUSION: In children, TIVA with remifentanil and propofol is a well-tolerated anaesthesia method, with a lower peroperative heart rate and less postoperative agitation compared with a desflurane-N2O based anaesthesia.

Adenoidectomy↗
PubMed1997

[Remifentanil with propofol or isoflurane. A comparison of the recovery times after arthroscopic surgery].

OBJECTIVES: Due to its unique pharmacokinetics, the new esterase-metabolised opioid remifentanil results in rapid post-anesthesia recovery. The aim of this clinical investigation was to compare recovery times after remifentanil anaesthesia in combination with hypnotic concentrations of either propofol or isoflurane. Dosages used in the study protocol were based on recommendations by the pharmaceutical manufacturer. METHODS: Patients (ASA status I-II) scheduled for elective arthroscopy were included in this trial. Without premedication in the morning, anaesthesia was induced identically in both groups: remifentanil bolus (1 microgram/kg), start of remifentanil-infusion (0.5 micrograms/kg/min), followed immediately by propofol (ca. 2 mg/kg). For maintenance of anaesthesia remifentanil (0.25 micrograms/kg/min) was combined with either a propofol infusion of 0.1 mg/kg/min or 0.5 MAC isoflurane (= 0.6 vol. %) in O2/air. Anaesthetic delivery was discontinued simultaneously with termination of surgery and recovery times were recorded. RESULTS: A total of 40 patients were studied at random in two groups of 20 each with comparable demographic data and anaesthetic technique (Tables 1 and 2). In both groups emergence was very rapid. Recovery times were significantly shorter for remifentanil-isoflurane than for remifentanil-propofol (Table 3): spontaneous ventilation 5.1 vs 8.1 min (P < 0.05), extubation 5.5 vs 8.6 min (P < 0.02), post-anaesthesia recovery score > or = 9 of 10 points 6.2 vs 11.3 min (P < 0.01), and arrival at PACU 16.2 vs 19.2 min (P < 0.01). Mild to moderate shivering was noted in 40% of all patients (9 cases following isoflurane, 7 following propofol). CONCLUSIONS: Using the manufacturer's recommended dosages, emergence after remifentanil anaesthesia is more rapid with 0.5 MAC isoflurane than with 0.1 mg/kg/min propofol. These results are most probably due to the different pharmacological properties of both co-anaesthetics, especially the applied dosages, and to different interactions with remifentanil. Present clinical experience suggests that a further dose reduction, especially for propofol, is possible. For both remifentanil groups emergence was remarkably rapid between return of consciousness and the awake state (on-off phenomenon), which might contribute to post-anaesthesia safety.

Adult↗
PubMed1997

The addition of clonidine to prilocaine for intravenous regional anaesthesia.

The effect of the addition of clonidine 2 micrograms kg-1 to prilocaine 0.5% for intravenous regional anaesthesia (IVRA) in the arm was investigated in 56 healthy patients using a randomized, double-blind study. The characteristics of the sensory and motor block, quality of analgesia, development of post-operative pain sensations and haemodynamic variables were studied in three groups (IVRA with prilocaine, IVRA with prilocaine and clonidine, IVRA with prilocaine and systemic application of clonidine at tourniquet release). There were no significant differences between the groups concerning the onset and recovery characteristics of sensory and motor blockade, post-operative pain or side effects. In those patients receiving clonidine, mean arterial pressure decreased significantly (24-28%, respectively) after tourniquet release, while heart rate remained unchanged. Clonidine as an adjunct to prilocaine seems to be of limited benefit during and after intravenous regional anaesthesia.

Adrenergic alpha-Agonists↗
PubMed1997

Ondansetron reduces nausea and vomiting after paediatric adenotonsillectomy.

The efficacy, safety and resource implications of a single intravenous dose of ondansetron (0.1 mg.kg-1, maximum 4 mg) were assessed in a multinational, multicentre, randomized, double-blind, placebo-controlled trial of 427 children aged 1-12 years, undergoing tonsillectomy with/without adenoidectomy. Emesis (retching and/or vomiting) and nausea were analysed separately. Significantly more ondansetron-treated children had no episodes of emesis (127/212 (60%) vs 100/215 (47%); P = 0.004) and experienced no postoperative nausea (135/211 (64%) vs 108/213 (51%); P = 0.004) in the first 24 h. Ondansetron also reduced the number of emetic episodes (P < 0.001), the time to the first emetic episode (P < 0.001) and overall nausea severity (P = 0.003). Significantly fewer ondansetron-treated children were rescued or withdrawn from the study (5% vs 10%; P = 0.042). Fewer ondansetron-treated patients required nursing intervention (34% vs 45%; P = 0.007) and the average intervention time was significantly shorter (4.6 vs 8.1 minutes; P = 0.001). Resources used to manage PONV were significantly reduced by ondansetron (43% vs 57%; P = 0.014).

Adenoidectomy↗
PubMed1997

[Comparative study of pethidine and clonidine for prevention of postoperative shivering. A prospective, randomized, placebo-controlled double-blind study].

OBJECTIVE: Patients with ischaemic heart disease and cardiac failure are endangered by an increase in oxygen consumption caused by postoperative shivering. The purpose of this study was to evaluate if pethidine and clonidine, which are well known for their effectiveness in the treatment of this undesirable side effect, can also prevent postoperative shivering if administered at the end of surgery. In addition it was investigated whether their intraoperative application influences the time of extubation and analgesics demand in the early postoperative period. METHODS: 60 patients (ASA I-II) scheduled for elective microsurgical vertebral disc resection were included in the study. After standardised induction of anaesthesia (5 mg x kg-1 thiopental, 2 micrograms x kg-1 fentanyl, 0.1 mg x kg-1 vecuronium) lungs were ventilated with isoflurane vaporized in 66% N2O and 33% O2. The concentration of the inhalation anaesthetic was adjusted to maintain a surgical plane of anaesthesia without supplementary doses of opioids. Patients were randomly allocated in a double-blind fashion to one of three groups (each n = 20) to receive either pethidine (0.3 mg x kg-1) or clonidine (2 micrograms x kg-1) or 0.9% saline (control) 5 minutes prior to the end of surgery. Heart rate, arterial blood pressure and rectal temperature were measured at defined times, as well as the recovery time between the end of anaesthesia and extubation, incidence of postoperative shivering, and the pain level of the patients with a visual analog scale. The frequency and total demand of analgesics were determined using patient controlled analgesia and recorded for two hours postoperatively. RESULTS: The incidence of postoperative shivering in the clonidine group (5%) was less than in the pethidine group (25%) and significantly less than in the saline group (55%). Heart rate and blood pressure values after the administration of clonidine were lower than after pethidine and significantly lower than after saline. The time between end of surgery and extubation was similar in all groups with an average of 18 minutes. No significant differences among the pain scores and the analgesics demand were noted among any of the groups, including the saline control-group. CONCLUSION: Intraoperative administration of clonidine (2 micrograms x kg-1) is suitable for prevention of postoperative shivering. Despite its sedative effects the recovery time until extubation was not prolonged. 0.3 mg x kg-1 pethidine proved to be less beneficial.

Adjuvants, Anesthesia↗
PubMed1997

[Craniosynostosis operations in childhood].

Premature osteosynthesis of one or more cranial bones, either intrauterine or within the first postnatal months, is defined as craniosynostosis. The resulting limitation of intracranial space can cause retardation of cranial growth which, in turn, leads to craniostenosis with increasing intracerebral pressure. Complex forms of craniosynostosis with concomitant malformations (i.e. Apert-, Crouzon-, and Pfeiffer syndromes) must be principally distinguished from simple craniosynostosis. This complex cranio-facial dysostosis is a premature osteosynthesis of cranial and facial bones. In general, as far as Germany is concerned, the incidence of cranio-synostosis amounts to 1/1000 births. If they remain untreated, many of these children will suffer from cortex-associated retardation of intelligence. Surgical management, therefore, is initiated at a very early stage, and should be performed in specialised centres. Recommendations for operation vary from an age of 4 to 36 months. However, an age of 6 months or more is the most frequently preferred age for surgical intervention. Severe respiratory disorders, as well as impossibility of enteral intake of nourishment, are considered absolute indications for surgery, independent of the age; elimination of the stigmatisation regarding environmental contacts of the child is another mandatory indication for operation. The goal of early surgery is reconstruction of physiological, cranial, and facial bone structures ("fronto-orbital" or "fronto-facial advancement"). Correction of craniofacial malformation may be associated with--in part--severe complications for the child. From the anaesthesiologist's point of view, this disease demands highly qualified perioperative management, since a variety of idiosyncrasies and risks must be taken into account: These are, for example, venous air embolism, hypothermia, disorders of water and electrolyte equilibrium, and, extremely vital, difficult intubation and substantial blood loss.

Anesthesia, General↗