Vanda G. Yazbeck-Karam

A single dose of propofol at the end of surgery for the prevention of emergence agitation in children undergoing strabismus surgery during sevoflurane anesthesia

Background:Emergence agitation in children after sevoflurane is common. Different drugs have been used to decrease its occurrence with variable efficacy. The authors compared the incidence and severity of emergence agitation in children who received a single dose of propofol at the end of strabismus surgery versus children who received saline. Methods:In this prospective, randomized, double-blind study, the authors enrolled 80 healthy children aged 2–6 yr. The children were randomly allocated to the propofol group (n = 41), which received 1 mg/kg propofol at the end of surgery, or to the saline group (n = 39), which received saline. Results:The mean scores on the Pediatric Anesthesia Emergence Delirium scale were significantly lower in the propofol group compared with the saline group (8.6 ± 3.9 vs. 11.5 ± 4.5; P = 0.004). Also, the incidence of agitation was significantly lower in the propofol group compared with the saline group (19.5% vs. 47.2%; P = 0.01). A threshold score greater than 10 on the Pediatric Anesthesia Emergence Delirium scale was the best discriminator between presence and absence of emergence agitation. Times to removal of the laryngeal mask airway (10.6 ± 1.5 vs. 9.4 ± 1.9 min; P = 0.004) and emergence times (23.4 ± 5.7 vs. 19.7 ± 5 min; P = 0.004) were significantly longer in the propofol group. However, discharge times were similar between the two groups (propofol: 34.1 ± 8.4 min; saline: 34.9 ± 8.6 min). More parents in the propofol group were satisfied. Conclusions:In children undergoing strabismus surgery, 1 mg/kg propofol at the end of surgery after discontinuation of sevoflurane decreases the incidence of agitation and improves parents’ satisfaction without delaying discharge from the postanesthesia care unit.

Laryngeal mask airway for ventilation during diagnostic and interventional fibreoptic bronchoscopy in children

Background:  The use of the flexible fibreoptic bronchoscope in infants and children has expanded to include both interventional and diagnostic bronchoscopy. The present report utilizes the laryngeal mask airway (LMATM) for ventilation and anaesthesia administration in children during fibreoptic bronchoscopy using an adult bronchoscope.

Prophylactic methylene blue in a patient with congenital methemoglobinemia.

PurposeTo report the beneficial effect of prophylactic methylene blue administration before induction of anesthesia in a patient with congenital methemoglobinemia.Clinical featuresA 26-yr-old male patient known to have congenital methemoglobinemia was scheduled forturbinectomy under general anesthesia. The patient was clinically cyanotic with a pulse oximetry of 91 %. Arterial blood gas analysis showed a partial pressure of oxygen (PaO2) of 81.3 mmHg associated with a fractional oxyhemoglobin of 80.7%, and a methemoglobin fraction of 0.159. Preoperativeiv administration of 1 mg·kg-1 of methylene blue resulted, within five minutes, in a decrease of methemoglobin fraction down to 0.05 associated with an increase of the fractional oxyhemoglobin saturation up to 94.7%. After two hours, the methemoglobin fraction decreased to 0.01 and the fractional oxyhemoglobin concentration increased to 97.7%. Induction of anesthesia as well as intraoperative and postoperative course were uneventful without any episode of hypoxemia. Postoperatively, the methemoglobin fractions remained low for 24 hr, to be followed by a gradual increase up to 0.02 on the second day to reach 0.094 on the fifth day.ConclusionThe prophylactic preoperative methylene blue administration in a patient with congenital methemoglobinemia significantly decreased the methemoglobin level and increased the fractional oxygen saturation with a consequent increase of the safety margin against perioperative hypoxemia.RésuméObjectifSignaler l’effet bénéfique de l’administration prophylactique de bleu de méthylène avant l’induction de l’anesthésie chez un patient atteint de méthémoglobinémie congénitale.Éléments cliniquesUn homme de 26 ans atteint de méthémoglobinémie congénitale devait subir une turbinectomie sous anesthésie générale. Le patient était cyanosé et présentait une sphygmo- oxymétrie de 91 %. L’analyse des gaz artériels a montré une pression partielle d’oxygène (PaO2) de 81,3 mmHg associée à une oxyhémo- globine fractionnelle de 80,7 % et à une fraction de méthémoglobine de 0,159. L’administration iv préopératoire de 1 mg·kg-1 de bleu de méthylène a donné, en moins de cinq minutes, une baisse de la frac- tion de méthémoglobine jusqu’à 0,05, et une hausse de la saturation d’oxyhémoglobine fractionnelle jusqu’à 94,7 %. Après deux heures, la fraction de méthémoglobine a baissé à 0,01 et la concentration d’oxy- hémoglobine fractionnelle a augmenté à 97,7 %. L’induction de l’anesthésie et l’évolution peropératoire et postopératoire ont été sans incident et sans épisode d’hypoxémie. Après l’opération, les fractions de méthémoglobine sont demeurées basses pendant 24 h et ont été suivies d’une hausse graduelle jusqu’à 0,02 le deuxième jour et 0,094 le cinquième jour.Conclusion : L’administrationprophylactique préopératoire de bleu de méthylène chez un patient atteint de méthémoglobinémie con-génitale a significativement réduit le niveau de méthémoglobine et augmenté la saturation en oxygène fractionnée, ce qui a augmenté la marge de sécurité contre l’hypoxémie périopératoire.PURPOSE To report the beneficial effect of prophylactic methylene blue administration before induction of anesthesia in a patient with congenital methemoglobinemia. CLINICAL FEATURES A 26-yr-old male patient known to have congenital methemoglobinemia was scheduled for turbinectomy under general anesthesia. The patient was clinically cyanotic with a pulse oximetry of 91%. Arterial blood gas analysis showed a partial pressure of oxygen (PaO(2)) of 81.3 mmHg associated with a fractional oxyhemoglobin of 80.7%, and a methemoglobin fraction of 0.159. Preoperative iv administration of 1 mg.kg(-1) of methylene blue resulted, within five minutes, in a decrease of methemoglobin fraction down to 0.05 associated with an increase of the fractional oxyhemoglobin saturation up to 94.7%. After two hours, the methemoglobin fraction decreased to 0.01 and the fractional oxyhemoglobin concentration increased to 97.7%. Induction of anesthesia as well as intraoperative and postoperative course were uneventful without any episode of hypoxemia. Postoperatively, the methemoglobin fractions remained low for 24 hr, to be followed by a gradual increase up to 0.02 on the second day to reach 0.094 on the fifth day. CONCLUSION The prophylactic preoperative methylene blue administration in a patient with congenital methemoglobinemia significantly decreased the methemoglobin level and increased the fractional oxygen saturation with a consequent increase of the safety margin against perioperative hypoxemia.

The effect of adjuvant drugs on the quality of tracheal intubation without muscle relaxants in children: A systematic review of randomized trials

Intubation without prior administration of muscle relaxants is a common practice in children. However, succinylcholine may be considered as the golden standard for optimizing intubating conditions. We conducted a systematic review of the literature to identify drug combinations that included induction of anesthesia with sevoflurane or propofol. Our aim was to select drug combinations that yield excellent intubating conditions ≥80%; we identified six combinations in children aged 1–9 years. Sevoflurane with remifentanil (1 or 2 μg·kg−1), lidocaine (2 mg·kg−1), or propofol (2 mg·kg−1) as the adjuvant shared the following characteristics: premedication with midazolam and/or ketamine, long sevoflurane exposure time, high inspired and endtidal sevoflurane concentration, and assisted ventilation. One combination using sevoflurane with propofol (3 mg·kg−1) without premedication, with shorter sevoflurane exposure time, and spontaneous breathing indicated that propofol may be the adjuvant of choice for a rapid sevoflurane induction. The only adjuvant identified in propofol induction was remifentanil (4 μg·kg−1). No serious adverse events were reported with these combinations.

A comparison between dexamethasone and methylprednisolone for vomiting prophylaxis after tonsillectomy in inpatient children: a randomized trial.

BACKGROUND:The frequent incidence of postoperative vomiting in children undergoing tonsillectomy, in addition to the occurrence of severe pain, may delay postoperative oral intake and lead to increased risk of dehydration. Thus, prophylactic therapy is indicated in this high-risk group. Glucocorticoids, such as dexamethasone and methylprednisolone, have anti-inflammatory and antiemetic properties with dexamethasone being frequently used. We hypothesized that methylprednisolone should be noninferior to dexamethasone for the prevention of vomiting in children after tonsillectomy. METHODS:We designed a randomized double-blind trial to compare the efficacy of a single prophylactic dose of 0.5 mg/kg dexamethasone with a dose of 2.5 mg/kg methylprednisolone on the incidence of postoperative vomiting during the first 24 hours (primary outcome) in children undergoing total or partial tonsillectomy with a noninferiority margin set at 9%. One hundred sixty children undergoing total or partial tonsillectomy under general anesthesia were randomly assigned to receive either IV dexamethasone 0.5 mg/kg (n = 79) or methylprednisolone 2.5 mg/kg (n = 81) after induction of anesthesia. Secondary analysis of all studied outcomes was also performed according to the type of surgery. RESULTS:An intention-to-treat analysis showed an overall incidence of vomiting of 30% in the dexamethasone group and of 22% in the methylprednisolone group (difference: 8%, 95% confidence interval [CI]: −5% to 21%). A per protocol analysis showed an incidence of vomiting of 32% and 23%, respectively (difference: 9%, and 95% CI of the difference: −5 to 23%, Psup = 0.28). The time and quality of oral intake and the duration of IV hydration, as well as pain and satisfaction scores and the need for analgesics, were similar between the 2 groups. The incidence of vomiting was also similar in patients who had total versus partial tonsillectomy; however, time to first oral intake, duration of IV hydration, and the need for analgesics were less with better satisfaction scores in partial versus total tonsillectomy patients. CONCLUSION:Methylprednisolone is at worst 5% less effective than dexamethasone by the intention-to-treat analysis, and by the per protocol analysis. Thus, it is noninferior to dexamethasone in preventing vomiting after tonsillectomy in children.

Methemoglobinemia after a Blast Injury

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Haloperidol Versus Ondansetron for Treatment of Established Nausea and Vomiting Following General Anesthesia: A Randomized Clinical Trial.

BACKGROUND: Haloperidol is an antipsychotic. At low doses, it is a useful agent for the prophylaxis of postoperative nausea and vomiting (PONV). However, its use for treating established PONV has not been well studied. METHODS: This randomized double-blinded trial tested whether haloperidol is noninferior to ondansetron for the early treatment of established PONV in adult patients undergoing general anesthesia. The primary outcome is whether patients were PONV free during the first 4 hours. The noninferiority margin was set at 15%. One hundred twenty patients with PONV received either haloperidol 1 mg intravenously (n = 60) or ondansetron 4 mg intravenously (n = 60). RESULTS: Data from 112 patients (59 in the haloperidol group and 53 in the ondansetron group) were analyzed. Thirty-five patients (52%) in the haloperidol group received 1 or 2 prophylactic antiemetics compared with 42 (79%) in the ondansetron group. Haloperidol was noninferior to ondansetron for the end point of complete response to treatment (defined as the rate of PONV-free patients) for the early (0–4 hour) and the 0- to 24-hour postoperative periods by both the per-protocol and intention-to-treat analyses. In the per-protocol analysis, complete responses in the early period were noted in 35 of 59 patients (59%) and 29 of 53 patients (55%) for the haloperidol and ondansetron groups, respectively (difference 5%; 95% confidence interval [CI]: −13% to 22 %), and in the 0- to 24-hour period in 31 of 59 patients (53%) and 26 of 53 patients (49%) for the haloperidol and ondansetron groups, respectively (difference 4%; 95% CI of the difference: −15% to 21%). In the intention-to-treat analysis, complete responses in the early period were noted in 35 of 60 patients (58%) and 29 of 60 patients (48%) for the haloperidol and ondansetron groups, respectively (difference 10%; 95% CI of difference: −8% to 27%) and in the 0- to 24-hour period in 31 of 60 patients (52%) and 26 of 60 patients (43%) for the haloperidol and ondansetron groups, respectively (difference 8%; 95% CI of the difference: −9% to 25%). All other PONV secondary outcomes were comparable. Twenty-five percent of patients in the haloperidol group were sedated versus 2% in the ondansetron group (P < .001; difference 23%; 95% CI of the difference: 11%–36%). Pain, satisfaction scores, need for analgesics, and changes in QTc intervals were not different between the 2 groups. CONCLUSIONS: Haloperidol is at worst 13% and 8% less effective than ondansetron by per-protocol analysis and by intention-to-treat analysis, respectively. Thus, it is noninferior to ondansetron for the early treatment of established PONV, but is associated with sedation.

Supplementation of retrobulbar block with clonidine in vitreoretinal surgery: effect on postoperative pain.

STUDY OBJECTIVE To evaluate the effect of clonidine when added to local anesthetics on duration of postoperative analgesia during retrobulbar block. DESIGN Prospective, randomized controlled trial. SETTING Operating room and Postanesthesia Care Unit of a university-affiliated hospital. SUBJECTS 80 ASA physical status 1, 2, and 3 patients undergoing vitreoretinal surgery with or without scleral buckling. INTERVENTIONS Patients in the control group (n = 40) received a retrobulbar block with 4.5 mL of lidocaine-bupivacaine and 0.5 mL of saline. Clonidine group patients (n = 40) received 4.5 mL of lidocaine-bupivacaine and 0.5 μg/kg of clonidine in a 0.5 mL volume. MEASUREMENTS The time to first analgesic request, frequency of postoperative pain, and number of postoperative analgesic requests per patient were assessed. MAIN RESULTS 37 patients in the control group (92.5%) versus 24 patients (60%) in the clonidine group reported pain postoperatively (P = 0.001), with a shorter time to first analgesic request noted in the control group (4.9 ± 3 vs 11.9 ± 5.3 hrs; P < 0.001). The median number of postoperative analgesic requests per patient during the first 24 hours was higher in the control group than the clonidine group [2 (0-3) vs. 1 (0-3); P < 0.001]. CONCLUSIONS The addition of clonidine 0.5 μg/kg to the local anesthetics of a retrobulbar block for vitreoretinal surgery decreases the frequency of postoperative pain and prolongs the time of analgesia.

Supplementation of Retrobulbar Block With Clonidine in Vitreoretinal Surgery: Effect on Postoperative Pain

T his prospective, randomized, controlled study was designed to assess the effect of clonidine when added to local anesthetics on duration of postoperative analgesia after retrobulbar block. Eighty American Society of Anesthesiologists physical status I, II, and III patients undergoing vitreoretinal surgery with or without scleral buckling at a university-affiliated hospital were studied. Patients in the control group (n = 40) received retrobulbar block with 4.5 mL of lidocaine-bupivacaine and 0.5 mL of saline. The clonidine group (n = 40) received 4.5 mL of lidocaine-bupivacaine and 0.5 Kg/kg of clonidine in a 0.5-mL volume. No intravenous sedation or analgesia was administered to patients in either group. The time to first analgesic request, frequency of postoperative pain complaints, and number of postoperative analgesic requests per patient were recorded and analyzed. Thirty-seven patients (92.5%) in the control group versus 24 patients (60%) in the clonidine group reported postoperative pain (P = 0.001), with a shorter time (mean T SD) to first analgesic request noted in the control group (4.9 T 3 vs 11.9 T 5.3 hours; P G 0.001). The median number of postoperative analgesic requests per patient during the first 24 hours was higher (median [range]) in the control group than in the clonidine group (2 [0Y3] vs 1 [0Y3]; P G 0.001). The investigators concluded that the addition of clonidine 0.5 Kg/kg to local anesthetics in a retrobulbar block for vitreoretinal surgery reduces the frequency of postoperative pain requiring intervention and prolongs the duration of analgesia.