Subhypnotic propofol infusion plus dexamethasone is more effective than dexamethasone alone for the prevention of vomiting in children after tonsillectomy

Background: Postoperative vomiting (POV) is a common complication after tonsillectomy. Dexamethasone is known to decrease postsurgical vomiting. In this study, we compared the effects of dexamethasone alone to dexamethasone plus propofol on postoperative vomiting in children undergoing tonsillectomy. Methods: In a randomized double‐blinded study, we evaluated 80 healthy children, aged 4–12 years, who underwent tonsillectomy with or without adenoidectomy. After anesthesia was induced by inhalation of sevoflurane, 0.15 mg·kg^?1 dexamethasone and 2 μg·kg^?1 fentanyl was administered i.v. to all patients. The patients in the dexamethasone plus propofol group received 1 mg·kg^?1 propofol before intubation and continuously after intubation at a rate of 20 μg·kg^?1·min^?1 until the surgery was completed. Data for postoperative vomiting were grouped into the following time periods: 0–4 and 4–24 h. Data were analyzed using a Student’s t‐test and chi‐squared analysis. Results: The percentage of patients exhibiting a complete response (defined as no retching or vomiting for 24 h) increased from 37.5% in the dexamethasone‐alone group to 75% in the dexamethasone plus propofol group (P = 0.001). Twenty‐two patients (55%) in the dexamethasone‐alone and nine patients (22.5%) in the dexamethasone plus propofol groups experienced vomited during 0–4 h (P = 0.003). Eight patients in the dexamethasone‐alone group and three patients in the dexamethasone plus propofol group received ondansetron as a rescue antiemetic during the postoperative period. Conclusion: For children undergoing tonsillectomy, intraoperative subhypnotic propofol infusion combined with dexamethasone treatment provides a better prophylaxis against postoperative vomiting than does dexamethasone alone.     

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 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 fust 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% expenenced 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 propofol is 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.     

Posttonsillectomy vomiting. Ondansetron or metoclopramide during paediatric tonsillectomy: are two doses better than one?

This randomized, double blinded, placebo controlled, prospective study compared the antiemetic efficacy of one preoperative dose of metoclopramide 0.25 mg·kg^?1 intravenously or ondansetron 0.15 mg·kg^?1 intravenously with two doses of the same drugs (second dose administered one h postoperatively) in 200 preadolescent children undergoing tonsillectomy with either isoflurane or propofol anaesthesia. The incidence of posttonsillectomy vomiting was significantly reduced (P < 0.005) by two doses of either metoclopramide or ondansetron (18% and 8%, respectively) compared with placebo (50%). No difference in posttonsillectomy vomiting exists between the children who received isoflurane and those who received a propofol infusion. Our results suggest that two doses of metoclopramide 0.25 mg·kg^?1 intravenously, like two doses of ondansetron 0.15 mg·kg^?1, are effective in reducing vomiting after tonsillectomy in children who have received either isoflurane or propofol anaesthesia.     

Low incidence of the oculocardiac reflex and postoperative nausea and vomiting in adults undergoing strabismus surgery

Purpose

To investigate the incidence of the oculocardiac reflex (OCR), and of postoperative nausea and vomiting (PONV) in adults undergoing strabismus surgery.

Methods

Adults (18 86 yr) undergoing inpatient strabismus surgery received 10 μg·kg atropine and 10 μg·kg alfentaniliv and were randomly allocated to: (A) 5 mg·kg^?1 thiopentoneiv, isoflurane/N₂O maintenance; (B) 3 mg·kg^?1 propofoliv. propofol/N₂O maintenance (10–14 mg·kg^?1hr·t-1); © 3 mg·kg^?1 propofoliv, propofol/air/O₂ maintenance (10–14 mg·kg^?1·hr^?1). Analyses were with the number-needed-to-treat/harm.

Results

In 97 adults the absolute nsk of OCR (13–20%) and PONV (21–31% after 24 hr) was low. with no differences between groups. Number-needed-to-treat to prevent PONV with propofol with or without N₂O compared with thiopentone-isoflurane was 7 to 11. Number-needed-to-harm for one OCR with propofol compared with thiopentone-isoflurane was 17.

Conclusion

Adults undergoing strabismus surgery with prophylactic atropine had a low risk of OCR and PONV independent of the anaesthetic technique used.     

Assessment of immediate post-anaesthetic recovery in young children following intravenous morphine infusions,halothane, and isoflurane

Within 15 minutes of terminating general anaesthesia, progressive recovery of consciousness, spontaneous ventilation and cough, and limb movements were assessed in 60 young children (age range 0-5 years, mean ± SEM; 2.$3 ± 0.34; weight 13.86 ± 0.41 kg). All patients were ASA physical status class I-III, received a standard intravenous induction (atropine 0.02 mg·kg^-1, thiopental sodium 5 mg·kg^-1, diazepam 0.2mg·kg^-1), were intubated with an orotracheat tube following the administration of metocurine, 0.4 mg·kg^-1, and were maintained under general anaesthesia with nitrous oxide and oxygen in a 70:30 mixture administered by a T-piece circuit. They were ventilated mechanically to maintain normal blood- oxygen tension and normocarbia. The patients were assessed in three equal groups according to the anaesthetic supplement they received. Group I received intravenous infusions of morphine sulfate (loading dose 60 μg·kg^-1administered over 5 minutes followed by a continuous intravenous infusion of 2 μg·kg^-1min^-1. Patients in Groups II and HI had 0.5 per cent halothane and 1.0 per cent isoflurane respectively added to the nitrous oxidel oxygen fresh gas mixture rather than morphine sulphate infusions. By the end of the study period, there was no significant difference in the degree of recovery between the morphine and the isoflurane groups but the patients in the halothane group had recovered to a lesser degree. Generally, the patients in the morphine group were awake but not crying, while those in the other two groups were less sedated.     

Vomiting after strabismus surgery in children: ondansetronvs propofol

Purpose

To compare the antiemetic efficacy and costs associated with two anaesthetic regimens in children undergoing strabismus surgery. One regimen contained halothane, nitrous oxide and ondansetron, while the other contained propofol and nitrous oxide.

Methods

Three hundred children aged 2–14 yr undergoing strabismus surgery were enrolled into this single-blind, randomized, stratified, blocked study with a balanced design. Anaesthesia was induced by inhalation with halothane/N₂O/O₂ (Group O) or with 2.5–3.5 mg·kg¹ propofol + 0.5 mg·kg^?1 lidocaineiv (Group P). Group O patients were administered 0.15 mg·kg^?1 ondansetron (maximum dose 8 mg)iv and all patients received atropine 20 μg·kg^?1 iv immediately after induction of anaesthesia. Anaesthesia was maintained with N₂O and halothane (Group O) or N₂O and propofol (Group P). Patients were followed for 24 hr after their operation primarily to assess the incidence of postoperative vomiting. For each case, the costs of the anaesthetic drugs administered and their associated intravenous administration tubing were determined. Drug costs were those prevailing at the study site at the time of the investigation. Fixed costs, such as the cost of the anaesthetic equipment were not assessed.

Results

Groups were similar with respect to demographic data. The incidence of vomiting in both groups was 11 % while in-hospital and 23% after discharge. Each episode of in-hospital vomiting prolonged discharge by 17 ± 4 min, P < 0.001. Mean cost per case for anaesthetic drugs was less in Group 0. 18 ± 8vs 21 ± 10 CDN$. mean ± SD. P < 0.01.

Conclusion

The two methods of antiemetic prophylaxis were equally effective. Propofol-based anaesthesia was more expensive.     

RETRACTED ARTICLE: Effective dose of granisetron for preventing postoperative emesis in children

Purpose

This study was to identify the minimum effective dose of granisetron, a selective 5-hydroxytryptamine type 3 receptor antagonist, to prevent postoperative vomiting in children who have undergone strabismus repair, tonsillectomy or tonsillectomy with adenoidectomy.

Methods

In a randomized, double-blind fashion, 80 healthy children aged 4–10 yr were assigned to receive either placebo (saline) or granisetron in a dose of 20, 40 or 80 μg· kg^?1 iv immediately following the induction of anaesthesia. All subjects received a standardized anaesthetic, which consisted of sevoflurane in nitrous oxide and oxygen. Rescue antiemetics were administered if two or more episodes of vomiting occurred. Postoperative pain was treated with acetaminophene pr or pentazocine iv. During the first 24 hr after anaesthesia, the frequencies of retching and vomiting were recorded in a standardized fashion by nursing staff while subjects were in a hospital.

Results

There were no differences among four treatment groups with regard to subject characteristics, surgical procedures, anaesthetic and postoperative management or adverse effects. The frequencies of these symptoms were as follows: 65%, 60%, 20% and 15% after administration of placebo, granisetron 20, 40 or 80 μg· kg^?1. Three children who had received either placebo or granisetron 20 μg · kg^?1 required another rescue antiemetic drug, whereas none who had received granisetron 40 or 80 μg · kg^?1 needed rescue drugs.

Conclusion

Granisetron 40 μg · kg^?1 is an effective antiemetic for preventing retching and vomiting following strabismus repair and tonsillectomy in children. Increasing the dose to 80 μg ·kg ^?1 provided no demonstrable benefit in reducing postoperative emesis.     

Droperidol decreases the incidence and the severity of vomiting after tonsillectomy and adenoidectomy in children

We assessed the effect of intravenous droperidol on the incidence and the severity of postoperative vomiting in children undergoing tonsillectomy and adenoidectomy. Seventy-nine ASA physical status I or II children aged 1.5 to 18 years (mean 6.1 years) were randomized into two groups. Group I received droperidol 50 μg·kg^?1 i.v. (maximum 1.25 mg), while group II received saline placebo immediately following the induction of general anaesthesia. All episodes of vomiting were recorded from the time of extubation until discharge the next morning. Of the 35 assigned to group I only 16 (46%) had one or more episodes of emesis compared to 31 of 44 (71%) in group II (P < 0.05). Patients in group I who vomited, did so only 1.9 ± 1.2 times compared to 4.6 ± 3.8 times for the control patients (P < 0.01). The authors conclude that droperidol at a dose of 50 μg·kg^?1 given at the time of induction of anaesthesia to healthy children decreases the incidence and the severity of vomiting during the first postoperative day following tonsillectomy and adenoidectomy.;     

Does propofol reduce vomiting after strabismus surgery in children?

Background: Previous studies have indicated that propofol anaesthesia may reduce the incidence of postoperative nausea and vomiting after strabismus surgery in children. This study was designed to investigate the incidence of vomiting after strabismus surgery at two different levels of propofol anaesthesia compared to thiopental/isoflurane anaesthesia. Methods: Ninety ASA class I or II children, aged 5–14 yrs were randomly assigned to one of three groups: Group T/I (n=30) induction with 5 mg kg^-1 of thiopental and maintenance with isoflurane, group P5 (n=31) induction with propofol 2 mg kg^-1, maintenance with propofol infusion 5 mg kg^-1 h^-1 or group P10 (n=29) induction with propofol 2 mg kg^-1, maintenance with propofol 10 mg kg^-1 h^_I. All received glycopyrrolate, vecuronium, fentanyl and controlled ventilation with O₂/N₂O 30/ 70. Ketorolac i.v. was given to prevent postoperative pain. If additional analgesia was needed, ibuprofen/acetaminophen or buprenorphine was given according to clinical need. Results: There were no differences between study groups with respect to age, weight, history of previous anaesthesia or emesis after previous anaesthesia, duration of anaesthesia, surgery or sleep after anaesthesia, or number of muscles operated. The incidence of vomiting was 37%, 29% and 28% in groups T/I, P5 and P10, respectively. There were no statistically significant differences between the three groups in the incidence of vomiting. The median age of patients who vomited was 7.5 (range 5.0–13.7) yrs while the median age of the patients who did not vomit was 9.1 (range 5.0–14.0) yrs (P < 0.01). Conclusion: In the present study, propofol anaesthesia compared to thiopental/isoflurane anaesthesia did not reduce the incidence of vomiting following strabismus surgery in children.     

Remifentanil-Propofol- Anästhesie bei Bandscheibenoperationen: ein Vergleich mit einer Desfluran-N2O- Inhalationsanästhesie Effekte auf Hämodynamik und Aufwachverhalten

Zusammenfassung Fragestellung: Unterscheidet sich eine totale intraven?se An?sthesie mit Propofol (P) und Remifentanil (R) von einer Inhalationsan?sthesie mit Desfluran (D) und Lachgas (L) bei lumbalen Bandscheibenoperationen hinsichtlich der Steuerbarkeit der Narkose, der Beeinflussung h?modynamischer Parameter, des Aufwachverhaltens und des postoperativen Analgetikabedarfs der Patienten? Methodik: 50 Patienten (ASA I–II, 18–65 Jahre) wurden randomisiert entweder einer P/R- oder D/L-Gruppe zugeteilt. Nach standardisierter Narkoseeinleitung (1 μg/kg Remifentanil, 1,5 mg/kg Propofol, 0,1 mg/kg Cisatracurium) wurde die An?sthesie in der D/L-Gruppe bedarfsadaptiert mit Desfluran in 50% N₂O und in der P/R-Gruppe mit 2 mg/kg/h Propofol und 0,5 μg/kg/min Remifentanil aufrechterhalten, wobei die Remifentanildosis nach 15 min halbiert wurde. Am Operationsende unmittelbar vor der Umlagerung in die horizontale Rückenlage wurde die Zufuhr der An?sthetika abrupt unterbrochen und folgende Aufwachzeiten erfa?t: Eintritt Spontanatmung (V_T>4 ml/kg), Extubation, Augen?ffnen, richtiges Benennen von Namen und Geburtsdatum und der Analgetikabedarf der ersten 2 postoperativen Stunden im Aufwachraum. Ergebnisse: Die Patienten der D/L-Gruppe reagierten auf den Intubationsreiz und die Hautinzision mit signifikanten Blutdruckanstiegen und zeigten signifikant h?here Herzfrequenzwerte, w?hrend ansonsten die h?modynamischen Parameter w?hrend des Narkoseverlaufs vergleichbar waren. Die Patienten der P/R-Gruppe erreichten signifikant früher eine stabile Spontanatmung (3,2 vs. 6,4 min), konnten früher extubiert werden (3,8 vs. 9,5 min), ?ffneten früher die Augen (3,0 vs. 11,5 min) und waren eher in der Lage, ihren Namen und Geburtsdatum zu benennen (4,8 vs. 14,3 min), wiesen aber auch signifikant h?ufiger Muskelzittern auf. Keine signifikanten Unterschiede fanden sich im Analgetikabedarf sowie in der Inzidenz von übelkeit und Erbrechen. Schlu?folgerung: Die Patienten erwachen aus der TIVA mit Propofol/Remifentanil schneller als aus der Desfluran/N₂O-Narkose und erreichen schneller ein h?heres Vigilanzniveau, wobei die geringe Intensit?t postoperativer Wundschmerzen nach Bandscheibenoperationen kein aufwendiges Konzept zur postoperativen Analgesie erfordert.      

Anaesthesia for non-cardiac surgery in heart-transplanted patients

This review documents the anaesthetic management, haemodynamic function and outcome in 18 of 86 heart-transplanted recipients, who returned for 32 non-cardiac surgical procedures at the Toronto Hospital from 1985 to 1990. General anaesthesia was administered in eight of the 27 elective operations and four of the five emergency operations. Induction medications included thiopentone (2–4 mg· kg^?1), fentanyl (1–7 μg· kg^?1) and succinylcholine (1–1.5 mg· kg^?1). Anaesthesia was maintained with a combination of oxygen /nitrous oxide and isoflurane or enflurane. Muscle relaxation was maintained with vecuronium or pancuronium. No delayed awakening or unplanned postoperative ventilation was observed. Neuroleptanaesthesia was administered to 63.0% and 20.0% of the elective and emergency operations, respectively. The anaesthetics included fentanyl (25–100 ng) and midazolam (0.5–1.5 mg) or diazemuls (2.5–5.0 mg). Spinal anaesthesia (75 mg lidocaine) was administered to only two of the 27 elective operations. No important haemodynamic changes were observed in any anaesthetic group, but lower systolic BP was found after induction and during maintenance periods in the patients who received general anaesthesia than in those who received neurolept-anaesthesia. However, no anaesthesia-related morbidity or mortality was noted. This suggests that general, neurolept- and spinal anaesthesia do not affect haemodynamic function or postoperative outcome in heart-transplanted recipients undergoing subsequent non-cardiac surgery.     

Retracted: Comparison of granisetron and droperidol in the prevention of vomiting after strabismus surgery or tonsillectomy in children

This prospective, randomized, double-blinded study evaluated the antiemetic efficacy of granisetron and droperidol in 80 ASA physical status I children, aged 4–10 years, undergoing strabismus surgery or tonsillectomy with or without adenoidectomy. After anaesthetic induction, the patients received either granisetron (40 μg·kg^?1, n=40) or droperidol (50 μg·kg^?1, n=40) intravenously. The incidence of vomiting during the first 24 h after anaesthesia was 15% and 38% after administering granisetron and droperidol, respectively(r)( P=0.02). The requirement for rescue antiemetic therapy for the treatment of two or more episodes of vomiting was 0% with granisetron and 18% with droperidol ( P=0.001). In conclusion, granisetron was superior to droperidol in reducing the incidence and frequency of postoperative vomiting in paediatric patients.     

Preoperative ketorolac increases bleeding after tonsillectomy in children

Purpose

To compare the incidence of vomiting following codeine or ketorolac for tonsillectomy in children.

Methods

We had planned to enrol 240 patients, aged 2–12 yr undergoing elective tonsillectomy into a randomized, single-blind study in University Children’s Hospital. The study was terminated, after 64 patients because interim analysis of the data by a blinded non-study scientist concluded that the patients were at undue risk of excessive perioperative bleeding. After induction of anaesthesia by inhalation with N₂O/halothane or with propofol 2.5?3.5 mg· kg^?1 iv, the children were administered 150 μg· kg^?1 ondansetron and 50 μg · kg^?1 midazolam. Maintenance of anaesthesia was with N₂O and halothane in O₂. Subjects were administered either 1.5 mg · kg^?1 codeine im or 1 mg· kg^?1 ketorolac iv before the commencement of surgery. Intraoperative blood loss was measured with a Baxter Medi-Vac® Universal Critical Measurement Unit. Postoperative management of vomiting and pain was standardized. Vomiting was recorded for 24 hr after anaesthesia. Data were compared with ANOVA, Chi-Square analysis and Fisher Exact Test.

Results

Thirty-five subjects received ketorolac. Demographic data were similar. The incidence of vomiting during the postoperative period was 31% in the codeine-group and 40% in the ketorolac-group. Intraoperative blood losses was 1.3 ± 0.8 ml · kg^?1 after codeine and 2.2 ± 1.9 ml · kg^?1 after ketorolac (mean ± SD) P < 0.05. Five ketorolac-treated patients had bleeding which led to unscheduled admission to hospital, P < 0.05, Exact Test.

Conclusion

Preoperative ketorolac increases perioperative bleeding among children undergoing tonsillectomy without beneficial effects.     

Propofol for tracheal intubation in children anesthetized with sevoflurane: a dose–response study

Background: Tracheal intubation during sevoflurane induction is frequently facilitated with i.v. propofol. We designed a dose–response study to evaluate the intubating conditions, and the incidence and duration of apnea after i.v. propofol in children. Methods/Materials: Sixty healthy children were randomly assigned to 0, 0.5, 1, 2 or 3 mg·kg^?1 i.v. propofol during sevoflurane/nitrous oxide anesthesia. Tracheal intubation was performed approximately 30 s after propofol by an anesthesiologist who was blind to the treatment. The anesthesiologist assessed the responses to laryngoscopy and intubation using a standardized scale. Incidence and duration of apnea after propofol as well as heart rate, and systolic blood pressure before and after laryngoscopy were recorded. Data were analyzed using one‐way and repeated measures anova , the Jonckheere–Terpstra test, and logistic regression, with P < 0.05 accepted. Results: The laryngoscopy score after 3 mg·kg^?1 propofol was less than that after 0 mg·kg^?1 (P < 0.01) and 0.5 mg·kg^?1 (P < 0.05). Incidence of apnea after propofol 3 mg·kg^?1, 8/10, was greater than after 0 mg·kg^?1, 3/14 (P < 0.011) and 0.5 mg·kg^?1, 3/12 (P < 0.03). Duration of apnea after 3 mg·kg^?1 was greater than after 0 and 0.5 mg·kg^?1 (P < 0.01). The risk of apnea increased 1.83 fold for each 1 mg·kg^?1 dose increase in propofol (P < 0.01). Mean heart rate and systolic pressure decreased with the main effect, time. Conclusion: During sevoflurane/nitrous oxide anesthesia, propofol 3 mg·kg^?1 provides superior intubating conditions with an increased incidence of and prolonged apnea compared with 0 and 0.5 mg·kg^?1.     

A comparison of intramuscular tenoxicam with intramuscular morphine for pain relief following tonsillectomy in children

A double blind trial was conducted to evaluate the analgesic efficacy of intramuscular tenoxicam for pain relief following tonsillectomy in children. Fifty children, aged 3–10 years, were randomly allocated to receive intramuscular tenoxicam 0.75 mg·kg^?1 or intramuscular morphine sulphate 0.2 mg·kg^?1 after induction of anaesthesia. Although the tenoxicam group required significantly more postoperative morphine (mean 57.8 μg·kg^?1 compared with 26.9 μg·kg^?1, P=0.025), the total morphine dose was significantly reduced after tenoxicam (57.8 μg·kg^?1 compared with 226.9 ug·kg^?1, P<0.0001). There was no difference between the quality of analgesia after discharge from recovery. The incidence of postoperative vomiting was significantly reduced after tenoxicam (20%) compared with morphine (71%).     

Intrathecal clonidine decreases propofol sedation requirements during spinal anesthesia in infants

Background: Propofol is a popular agent for providing procedural sedation in pediatric population during lumbar puncture and spinal anesthesia. Adjuvants like clonidine and fentanyl are administered intrathecally to prolong the duration of spinal anesthesia and to provide postoperative analgesia. We studied the propofol requirement after intrathecal administration of clonidine or fentanyl in infants undergoing lower abdominal surgeries. Methods: Sixty‐five ASA I infants undergoing elective lower abdominal surgery under spinal anesthesia were assigned into four groups in this prospective randomized double‐blinded study. Group B received bupivacaine based on body weight (<5 kg = 0.5 mg·kg⁻¹; 5–10 kg = 0.4 mg·kg⁻¹). Group BC received 1 μg·kg⁻¹ of clonidine with bupivacaine, group BF received 1 μg·kg⁻¹ of fentanyl with bupivacaine, and patients in group BCF received 1 μg·kg⁻¹ each of clonidine and fentanyl with bupivacaine. A bolus of 2–3 mg·kg⁻¹ of propofol bolus was administered for lumbar puncture. Sedation was assessed using a six‐point sedation score (0–5) and a five‐point reactivity score (0–4) which was based on a behavioral score. After achieving a sedation and reactivity score of 3–4, the patients were placed lateral in knee chest position and lumbar puncture performed and test drug administered. Further intraoperative sedation was maintained with an infusion of 25–50 μg·kg⁻¹·min⁻¹ of propofol infusion. Results: The mean ± sd infusion requirement of propofol decreased from 35.5 ± 4.5 in group B to 33.4 ± 5.4 μg·kg⁻¹·min⁻¹ in group BF and further decreased to 16.7 ± 6.2 μg·kg⁻¹·min⁻¹ and 14.8 ± 4.9 μg·kg⁻¹·min⁻¹ in group BC and BCF, respectively. There were no statistically significant differences between BC and BCF groups. The mean sedation and reactivity scores were higher in groups BC and BCF when compared to groups B and BF. Conclusion: Our study show that the requirement of propofol sedation reduces with intrathecal adjuvants. The reduction was significant with the addition of clonidine and clonidine–fentanyl combination as opposed to bupivacaine alone or with fentanyl. There was no significant difference in propofol infusion requirement with the use of bupivacaine alone or with fentanyl.     

Ondansetron is a better prophylactic antiemetic than droperidol for tonsillectomy in children

Both intravenous ondansetron (OND) and droperidol (DROP) have been observed to reduce vomiting after tonsillectomy in children. This randomized, double-blind investigation compared the effect of OND and DROP on vomiting after outpatient tonsillectomy in 276 healthy children age 2– 12 yr. All subjects received a standardized anaesthetic, which consisted of induction with either propofol or halothane/N₂O, vecuronium 0.1 mg · kg^{? 1} on an as needed basis, maintenance with halothane/ N₂O, midazolam and codeine, and reversal of neuromuscular blockade with neostigmine and atropine on an as needed basis. Subjects were given either OND 150 μg · kg^{? 1} or DROP 50 μg · kg^{? 1} iv after induction of anaesthesia. Rescue antiemetics in the hospital were administered to patients who vomited × 2 and × 4, respectively. Postoperative pain was treated with morphine, codeine and/or acetaminophen. For 24 hr following surgery, emesis was recorded by nursing staff while subjects were in hospital, and by parents following discharge from hospital. The two groups were similar with respect to demographic data, induction technique and anaesthesia time. The frequency of in-hospital emesis was 16% in the OND-patients and 30% in the DROP-group, P < 0.05. The OND-subjects required fewer rescue antiemetics, 5% vs 13%, P < 0.05. The overall incidence of emesis was 45% in the OND-group and 57% in the DROP-group, P < 0.05. In conclusion, ondansetron was a superior prophylactic antiemetic for tonsillectomy in children when compared to droperidol.     

Comparison of propofol-fentanyl with propofol-fentanyl-ketamine combination in pediatric patients undergoing interventional radiology procedures

Background: With an increase in the frequency of interventional radiology procedures in pediatrics, there has been a corresponding increase in demand for procedural sedation to facilitate them . The purpose of our study was to compare the frequency of adverse effects, sedation level, patient recovery characteristics in pediatric patients receiving intravenous propofol fentanyl combination with or without ketamine for interventional radiology procedures. Our main hypothesis was that the addition of ketamine would decrease propofol/fentanyl associated desaturation. Methods and materials: Sixty consenting American Society of Anesthesia physical status I–III pediatric patients undergoing interventional radiology procedures under sedation were studied according to a randomized, double‐blinded, institutional review board approved protocol. Group 1 received propofol 0.5 mg·kg^?1 + fentanyl 1 μg·kg^?1 + ketamine 0.5 mg·kg^?1, and group 2 received propofol 0.5 mg·kg^?1 + fentanyl 1 μg·kg^?1 + same volume of %0.9 NaCl intravenously. Results: While apnea was not observed in any of the groups, there were three cases (10%) in group 1, and nine cases (30%) in group 2 with oxygen desaturation (P = 0.052). In group 1, 12 (40%) patients and, in group 2, 21 (70%) patients required supplemental propofol during the procedure (P = 0.021). There was no evidence for difference between groups in terms of other side effects except nystagmus. Conclusions: In conclusion, addition of low dose ketamine to propofol‐fentanyl combination decreased the risk of desaturation and it also decreased the need for supplemental propofol dosage in pediatric patients at interventional radiology procedures.     

Isoflurane compared with nitrous oxide anaesthesia for intraoperative monitoring of somatosensory-evoked potentials

Intraoperative monitoring of somatosensoryevoked potentials is a routine procedure. To determine the depressant effect of nitrous oxide relative to isoflurane, the authors recorded the scalp, cervical and brachial plexusevoked responses to stimulation of the median nerve under different anaesthetic conditions. Eight subjects, age 35 ± 6 (SD) yr, weight 68 ± 12 kg, were studied. Following recording of awake control responses, anaesthesia was induced with thiopentone 5 mg· kg^{? 1} and fentanyl 3 μg· kg^{? 1} and was followed by succinylcholine 1 mg· kg^{? 1}. During normocapnia and normothermia, and with a maintenance infusion of fentanyl 3 μg · kg^{? 1}· hr^{? 1}, evoked potential recording was repeated under three different anaesthetic conditions; 0.6 MAC nitrous oxide, 0.6 MAC nitrous oxide ± 0.6 MAC isoflurane, and 0.6 MAC isoflurane. Among the anaesthetic conditions, the combination of nitrous oxide-isoflurane had the most depressant effect on the cortical amplitude (67 ± 4% reduction, P < 0.05). Nitrous oxide decreased the cortical amplitude more than an equipotent dose of isoflurane (60 ± 4% vs 48 ± 7%, P < 0.05). The latency was unchanged by nitrous oxide, but increased slightly by isoflurane and isofluranenitrous oxide anaesthesia (1.0 and 0.9 msec respectively, P < 0.05). We conclude that somatosensory-evoked potential monitoring is feasible both during nitrous oxide anaesthesia and isoflurane anaesthesia, but the cortical amplitude is better preserved during 0.6 MAC of isoflurane alone relative to 0.6 MAC of nitrous oxide alone. The depressant effect is maximal during nitrous oxideisoflurane anaesthesia but less than the predicted additive effect.     

Propofol, but not thiopentone or etomidate, enhances isoflurane-induced coronary vasodilatation in dogs

Purpose

To test the hypothesis that thiopentone, propofol, and etomidate alter the coronary vascular effects of abruptly administered isoflurane.

Methods

Dogs (n = 6) received inspired isoflurane 5% in the presence of thiopentone (20 mg·kg^?1 induction dose and 20 mg·kg^?1·hr^t-1 infusion), propofol (5 mg·kg^?1 induction dose and 40 mg·kg^?1·hr^?1 infusion), etomidate (2 mg·kg^?1 induction dose and 5 mg·kg^?1·hr^?1 infusion), or isoflurane (1.0 MAC) anaesthesia in a random fashion. Haemodynamics were assessed in the conscious state, during baseline anaesthesia, and at 30 sec intervals for five minutes after beginning isoflurane 5%.

Results

Rapidly administered isoflurane caused greater (P < 0.05) reductions in coronary vascular resistance in thiopentoneor propofol-than in isoflurane-anaesthetized dogs. Isoflurane produced greater (P < 0.05) increases in the ratio of coronary blood flow velocity to pressure-work index (an index of myocardial oxygen consumption; +109 ± 19 % during isoflurane alonevs + 182 ± 27 % change from baseline during propofol and isoflurane) consistent with relatively greater direct coronary vasodilatation during baseline propofol than during baseline isoflurane anaesthesia. Isoflurane caused larger increases in coronary blood flow velocity in dogs anaesthetized with etomidate concomitant with higher coronary perfusion pressure and pressure-work index than in those anaesthetized with isoflurane alone.

Conclusions

The results suggest that thiopentone, propofol, and etomidate each uniquely modify the coronary vascular responses to abrupt administration of high inspired concentrations of isoflurane in chronically instrumented dogs.