Regional anaesthesia for hernia repair in children: local vs caudal anaesthesia

The purpose of this study was to compare the effect of local anaesthesia (LA) with that of caudal anaesthesia (CA) on postoperative care of children undergoing inguinal hernia repair. This was a randomized, single-blind investigation of 202 children aged 1–13 yr. Anaesthesia was induced with N₂O/O₂ and halothane or propofol and maintained with N₂O/O₂/halothane. Local anaesthesia included ilioinguinal and iliohypogastric nerve block plus subcutaneous injection by the surgeon of up to 0.3 ml · kg^?1 bupivacaine 0.25% with 5 μg · kg^?1 adrenaline. The dose for caudal anaesthesia was 1 ml · kg^?1 up to 20 ml bupivacaine 0.2% with 5 μg · kg^?1 adrenaline. Postoperative pain was assessed with mCHEOPS in the anaesthesia recovery room, with postoperative usage of opioid and acetaminophen in the hospital, and with parental assessment of pain with a VAS. Vomiting, time to first ambulation and first urination were recorded. The postoperative pain scores and opioid usage were similar; however, the LA-group required more acetaminophen in the Day Care Surgical Unit. The incidence of vomiting and the times to first ambulation and first urination were similar. The LA-patients had a shorter recovery room stay (40 ± 9 vs 45 ± 15 min, P < 0.02). The postoperative stay was prolonged in the CA group (176 ± 32 vs 165 ± 26 min, P = 0.02). We conclude that LA and CA have similar effects on postoperative care with only slight differences.     

The effects of prophylactic dixyrazine on postoperative vomiting after two different anaesthetic methods for squint surgery in children

The incidence of postoperative vomiting after squint surgery was studied for two anaesthetic techniques with and without prophylactic dixyrazine. After induction, anaesthesia was maintained with either fentanyl/pancuronium/nitrous oxide or halothane/nitrous oxide in two randomly selected groups of 58 children each. Half of the children in each group were randomly allocated to receive dixyrazine 0.25 mg kg^-1 i.v. after surgery had been completed but before reversal of muscle relaxants or termination of anaesthesia. With prophylactic dixyrazine the incidence of postoperative vomiting was significantly reduced from 69% (20/29) to 21% (6/29) in the fentanyl group and from 45% (13/29) to 10% (3/29) in the halothane group. Without prophylactic dixyrazine, 20 of 29 children in the fentanyl group vomited compared to 13 of 29 in the halothane group (n.s.). Thus, prophylactic dixyrazine reduced the incidence of vomiting in children given either opioid or halothane anaesthesia for squint surgery. In comparable groups avoidance of opioid anaesthetic technique and use of prophylactic dixyrazine resulted in a greatly reduced incidence of vomiting.     

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.     

Oral ondansetron decreases vomiting after tonsillectomy in children

Vomiting is a common, unpleasant aftermath of tonsillectomy in children. Intraoperative intravenous ondansetron (OND) reduces vomiting after this operation. Our doubleblind, placebocontrolled, randomized investigation studied the effect of the oral form of OND on vomiting after outpatient tonsillectomy in children. We studied 233 healthy children age 2–14 yr undergoing elective tonsillectomy. Subjects were given placebo (PLAC) or OND 0.1 mg · kg^?1 rounded off to the nearest 2 mg one hr before surgery. Anaesthesia was induced with either propofol or halothane/N₂O. Vecuronium 0.1 mg · kg^?1 was administered at the discretion of the anaesthetist. Anaesthesia was maintained with halothane/N₂O, 50 μg · kg^?1 midazolam iv and 1–1.5 mg · kg^?1 codeine im. At the end of surgery, residual neuromuscular blockade was reversed with neostigmine and atropine. All episodes of inhospital emesis were recorded by nursing staff. Rescue antiemetics in the hospital were 1 mg · kg^?1 dimenhydrinate ivfor vomiting × 2 and 50 μg · kg^?1 droperidol iv for vomiting × 4. Parents kept a diary of emesis after discharge. Postoperative pain was treated with morphine, codeine and/or acetaminophen. The two groups were similar with respect to demographic data, induction technique and anaesthesia time. Oral OND (n = 109) reduced postoperative emesis from 54% to 39%, P < 0.05. This effect was most dramatic inhospital, where 10% of the OND-patients and 30% of the PLAC-group vomited, P < 0.05. The OND-subjects required fewer rescue antiemetics, 7% vs 17%, P < 0.05. In conclusion, oral ondansetron decreased the incidence of vomiting after outpatient tonsillectomy in children.     

Nitrous oxide and postoperative vomiting in children undergoing myringotomy as a day case

The effect of avoiding nitrous oxide during anaesthesia for myringotomy as an outpatient procedure in children aged 18 months to 10 yr was investigated. One hundred and four children were allocated randomly to receive either nitrous oxide, oxygen and halothane or oxygen and halothane for maintenance of anaesthesia. Ten of 47 (21%) children receiving nitrous oxide experienced postoperative vomiting, compared with two of 48 (4%) of those that did not receive nitrous oxide (P < 0.05). The possible mechanisms are discussed.     

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.     

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.     

Propofol reduces the incidence of vomiting after tonsillectomy in children

We compared the effect of a propofol-based anaesthetic to an isoflurane-based anaesthetic on the incidence of postoperative vomiting in children following tonsillectomy. Thirty-nine children were enrolled in the study and randomized to receive one of the proposed anaesthetics. All patients underwent a mask induction with halothane, nitrous oxide, and oxygen. Intravenous access was established and all children received fentanyl (2–4 μg·kg^-1) i.v., mivacurium (0.3 mg·kg^-1) i.v. and acetaminophen (10–15 mg·kg^-1) p.r. Following tracheal intubation, patients received either isoflurane (0.8–1.6%) or propofol (120–180 μg·kg^-1 min^-1) i.v. with nitrous oxide 70%/oxygen 30% for maintenance of anaesthesia. Vital signs were maintained within 20% of baseline. All patients were extubated in the operating room. PACU nursing staff recorded episodes of vomiting for 4–6 h prior to discharge. A telephone interview the following day was also used for data recovery. Age, sex, and duration of the procedure were not significantly different between the two study groups. Of 19 patients who received propofol, four vomited (21%); in contrast, of the 20 patients who received isoflurane, 11 vomited (55%). This difference is significant (P= 0.048 two-tailed Fisher's Exact Test). These data suggest that using propofol for anaesthesia can diminish the incidence of vomiting following tonsillectomy.     

Halothane concentrations required to block the cardiovascular responses to incision (MAC CVR) in infants and children

The purpose of this study was to determine the halothane concentration in N₂O required to block the cardiovascular responses to skin incision (MAC CVR) in infants and children. We studied 64 unpremedicated ASA 1 infants and children (one month to seven years). In each infant or child, anaesthesia was induced slowly with halothane and N₂O, and an endotracheal tube was placed. The MAC CVR was assessed, after a steady state end-tidal halothane concentration had been established for ten minutes, by the “up and down technique” of Dixon. Positive responses were defined as an increase in MAP or HR > 10%. The MAC CVR50 values of halothane with 60% N₂O were 1.16 ± 0.23% at 1–6 mo, 1.17 ± 0.18% at 7–12 mo, 0.95 ± 0.26% at 1–3 yr, and 1.12 ± 0.16% at 4–7 yr. The value at 1–3 years children was less than those in the other age groups (P < 0.05). The changes of MAP were correlated with changes of both HR and pupillary diameter. These results indicate that the values of MAC CVR50 of halothane in infants and children are higher than those required to block motor responses (MAC). The halothane requirement to block cardiovascular responses is lowest in the children aged one to three years.     

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.     

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.     

Vomiting and common paediatric surgery

Postoperative vomiting is a common and unpleasant complication. The purpose of the present study was to verify if dexamethasone reduces the incidence of vomiting when injected IV in children anaesthetized with halothane for common paediatric operations. We also studied the incidence of vomiting when sevoflurane was used instead. Five hundred and 69 boys, aged 2-12 years (ASA physical status I, II), scheduled for inguinal field surgery were randomly assigned to receive halothane, halothane and dexamethasone and sevoflurane in three groups: halothane (n=180), halothane and IV dexamethasone (n=188) and sevoflurane (n=201). Anaesthesia was induced by inhalation of halothane or sevoflurane in oxygen and nitrous oxide and was maintained at minimum alveolar concentration of each agent throughout the surgery. For intra- and postoperative pain control iliac crest block was used in all the boys. Vomiting was defined as any expulsion of liquid gastric contents. The incidence of postoperative vomiting was 23% in the halothane group, which was significantly greater than that in the other groups (halothane and dexamethasone group, 9%; sevoflurane group, 13%). In conclusion, dexamethasone reduces the incidence and frequency of multiple emetic episodes when administered intravenously after halothane anaesthesia; sevoflurane reduces the overall incidence of vomiting, but not multiple emetic episodes.     

Einfluß von Propofol auf das Erbrechen nach Strabismusoperationen bei Kindern

Strabismus surgery in children is associated with a high incidence of postoperative nausea and vomiting (PONV). Methods. Ninety ASA class I and II children aged 6 to 16 years and scheduled for strabismus surgery were randomly assigned to one of the following groups: Group 1 (n=30): thiopentone 4–6 mg/kg i.v., halothane 0.8–1.5%, N₂O―O₂ 2:1, no opioids, droperidol 75 μg/kg i.v.; Group 2 (n=30): propofol 2–3 mg/kg i.v., propofol 6–9 mg/kg·h, alfentanil 30 μg/kg·h, N₂O-O₂ 2:1, no antiemetics; Group 3 (n=30): similar to group 2, but ventilation with air and O₂ 2:1. All patients were mechanically ventilated during anaesthesia and gastric contents were aspirated. Recovery scores were calculated for 2 h, emetic scores for 24 h postoperatively. Results. Emetic episodes during the first 24 h were recorded in 40% of group 1, 26.7% of group 2, and 40% of group 3 patients. The oculocardiac reflex occurred only in groups 2 and 3, but not in group 1 children. Recovery scores were significantly higher in groups 2 and 3 compared to group 1. Conclusions. In children undergoing strabismus surgery propofol/alfentanil anaesthesia without antiemetics may be equal or even superior to thiopentone/halothane anaesthesia combined with droperidol in terms of PONV and recovery from anaesthesia.     

Studies in postoperative sequelae. Nausea and vomiting—still a problem

We collected data on postoperative nausea and vomiting from 3850 patients aged 11–91 years. Thirty-seven percent of the 3244 patients who received a general anaesthetic reported nausea and 23.2% vomited. Twenty percent of the 606 patients who received a local anaesthetic reported nausea and 11.4% vomited. Of the general anaesthetic patients reporting nausea, 72.2% were women, and the mean age was lower than for those who did not (p < 0.001). Similarly for vomiting, 74.0% were women and again the mean age was lower (p < 0.001). Of the local anaesthetic patients reporting nausea, 62.0% were women and the mean age was lower than for those who did not (p < 0.001). Similarly for vomiting, 68.1% were women and again the mean age was lower (p < 0.001). Anxiety before general, but not local, anaesthesia was associated with postoperative nausea (p < 0.001) but not vomiting. Patients from the gynaecological, orthopaedic, ENT and general surgical wards had higher incidences of postoperative nausea and vomiting. Linear visual analogue pain scores were higher in patients with postoperative nausea and vomiting in both general and local anaesthesia groups (p < 0.001).     

Perphenazine decreases vomiting by children after tonsillectomy

Purpose

To test the hypothesis that perphenazine decreases the incidence of vomiting by children after tonsillectomy.

Methods

Healthy children (n = 260) aged 2–12 yr undergoing elective tonsillectomy on a day care surgical basis were studied in this randomised, stratified, blocked, double-blind investigation. General Anaesthesia was induced intravenously with propofol or by inhalation with halothane and N₂O. Perphenazine 70 μg·kg^?1 up to 5 mg or placebo iv was administered before surgery. Management of perioperative fluids, emesis and pain were all standardised.

Results

The groups were similar with respect to demographic data. There was less vomiting after perphenazine during the first 24 hr after surgery 42% (95% CI = 34%–50%) vs 57% (95% CI = 48%–66%, placebo), P < 0.01. On the day of surgery, both in and out-of hospital emesis were decreased by perphenazine. The perphenazine treated patients required fewer rescue antiemetics than the control group, P < 0.05. Each episode of in-hospital vomiting delayed discharge by 20 ± 7 min (mean ± SD). P = 0.007.

Conclusion

The prophylactic administration of perphenazine decreases vomiting by children after tonsillectomy.     

Midazolam reduces vomiting after tonsillectomy in children

The purpose of this study was to assess the effect of midazolam on vomiting after tonsillectomy in children. We compared 215 children aged 1.5–14 yr undergoing tonsillectomy or adenotonsillectomy under general anaesthesia with nitrous oxide and halothane. In a double-blind fashion the subjects were administered either placebo or midazolam 75 μg · kg^?1 iv after induction of anaesthesia. After the operation, the number of emetic episodes and the length of stay in hospital were recorded. The groups were similar with respect to age, weight, sex, mode of induction, duration of anaesthesia, surgical procedure, opioid administration and length of stay in the PAR and the Day Care Surgical Unit. The 108 midazolam-treated children had a lower incidence (42% vs 57%) of vomiting than the placebo group, P < 0.02. The placebo group had a higher incidence (9% vs 2%) of unscheduled admissions to hospital due to nausea and vomiting, P < 0.05. It is concluded that midazolam administered intravenously to children intraoperatively reduces vomiting after tonsillectomy.     

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.;     

Butorphanol: an opioid for day-care paediatric surgery

The purpose of this study was to compare the side effects and efficacy of equianalgesic doses of morphine (M) and butorphanol (B) in children undergoing similar surgical procedures associated with moderate postoperative pain. We studied 156 healthy children aged 1.5–13 yr who underwent elective inguinal herniorrhaphy or orchidopexy. After induction of anaesthesia subjects were given 150 μg · kg^?1 M or 30 μg · kg^?1 B following a randomized, stratified, blocked and double-blind design. A standardized anaesthetic was administered, which included 1.5% halothane, vecuronium, droperidol and mechanical ventilation. The postsurgical four-hour follow-up included assessment of pain, vomiting and respiratory depression. Pain was assessed with mCHEOPS and analgesics were administered when indicated in the recovery room. Each opioid was administered to a group of 78 patients. Within each group, 25 subjects had an iv induction, 21 children had an orchidopexy and 57 had inguinal hernia repairs. The groups were similar with respect to age, weight, and length of surgery. The choice of opioid did not affect recovery times from anaesthesia. Analgesic requirements were similar among the groups. Ten minutes after arrival in the recovery room the B-subjects had a lower pain score than the M-patients. Postoperative vomiting was less among the B-subjects: 14% vs 28%, P = 0.03. Two M-patients required an unscheduled admission to hospital because of vomiting. It is concluded that butorphanol has few advantages over morphine in the population studied.     

The efficacy of clonidine for reducing perioperative haemodynamic changes and volatile anaesthetic requirements in children

Background: Oral clonidine given as a premedicant in adults has been shown to reduce intraoperative inhalation anaesthetic requirements and provide perioperative haemodynamic stability. We conducted the current study to ascertain whether or not these beneficial effects of clonidine can be reproduced in children. Methods: In a prospective, randomized, double-blind, controlled clinical trial, 60 children (ASA I) aged 5–11 yr, received placebo (control), 2 μg kg^-1 clonidine, or 4 μg kg^-1 clonidine orally 105 min before induction of anaesthesia. Anaesthesia was induced with halothane, nitrous oxide in oxygen via mask and maintained with halothane and 60% nitrous oxide in oxygen. The halothane concentration was titrated to the concentration required to maintain haemodynamic stability (defined as 20% of blood pressure (BP) and heart rate (HR)) for maintenance of anaesthesia. The end-tidal concentration of halothane was monitored throughout anaesthesia. On completion of surgery, nitrous oxide and halothane were discontinued. Following confirmation of recovery from anaesthesia and muscle relaxation, the endotracheal tube was removed. Results: Higher inspired concentrations of halothane (%) were required in the control and 2 μg kg^-1 clonidine-treated groups (mean SD: 1.1 ±0.2 and 1.0±0.2, respectively) than in the 4 μg kg^-1 clonidine-treated group (0.6±0.1) for haemodynamic stability (P<0.05). Clonidine, 4 μg kg^-1, significantly reuced the intraoperative lability (coefficient of variation) of systolic and diastolic BP and HR compared with the other two regimens. Conclusion: Oral clonidine premedication at a dose of 4 μg kg^-1 provided intraoperative haemodynamic stability and reduced anaesthetic requirements in children. However, we are unable to extrapolate these observations to younger children and infants.     

Motion sickness and postoperative vomiting in children

BACKGROUND: Motion sickness is considered an important risk factor for postoperative nausea and vomiting in children. The aim of this study was to verify the impact of motion sickness on the incidence of vomiting after routine surgery in children, and to compare the incidence of vomiting, after combined regional/general anaesthesia, using either halothane or sevoflurane. METHODS: We prospectively studied 420 children (369 males and 51 females) who received general anaesthesia and inguinal field block for common paediatric surgery. The children were randomly allocated into one of two groups (halothane or sevoflurane). In the 200 children in the first group (H), general anaesthesia was induced and maintained with halothane, whereas in the 220 children in the second group (S), anaesthesia was induced and maintained with sevoflurane. RESULTS: There were 79 children with a prior history of motion sickness (MS+) and 341 without such a history (MS-). In the MS+ population, the incidence of vomiting was similar in both H and S groups, being around 33%. However, repeated episodes of vomiting in MS+ children were more frequent when halothane was used. In the MS- group, the incidence of vomiting was significantly greater in the H group (19%) than in the S group (8%). CONCLUSIONS: In the postoperative period, we found that MS+ children vomit more than MS- children, regardless of the inhalation anaesthetic used. However, MS- children displayed a higher incidence of vomiting when halothane was used rather than sevoflurane.