The effect of intranasal administration of remifentanil on intubating conditions and airway response after sevoflurane induction of anesthesia in children.

BACKGROUND: Intubation without the use of muscle relaxants in children is frequently done before IV access is secured. In this randomized controlled trial, we compared intubating conditions and airway response to intubation (coughing and/or movement) after sevoflurane induction in children at 2 and 3 min after the administration of intranasal remifentanil (4 mcg/kg) or saline. METHODS: One hundred eighty-eight children, 1-7-yr old, were studied. Nasal remifentanil (4 mcg/kg) or saline was administered 1 min after an 8% sevoflurane N2O induction. The sevoflurane concentration was then reduced to 5% in oxygen, and ventilation assisted/controlled. An anesthesiologist blinded to treatment assignment used a validated score to evaluate the conditions for laryngoscopy and response to intubation. Blood samples for determination of remifentanil blood concentrations were collected from 17 children at baseline, 2, 3, 4, and 10 min after nasal administration of remifentanil. RESULTS: Good or excellent intubating conditions were achieved at 2 min (after the remifentanil bolus) in 68.2% and at 3 min in 91.7% of the children who received intranasal remifentanil versus 37% and 23% in children who received placebo (P<0.01). The mean remifentanil plasma concentrations (+/-sd) at 2, 3, 4, and 10 min were 1.0 (0.60), 1.47 (0.52), 1.70 (0.46), and 1.16 (0.36) ng/mL, respectively. Peak plasma concentration was observed at 3.47 min. There were no complications associated with the use of nasal remifentanil. CONCLUSIONS: Nasal administration of remifentanil produces good-to-excellent intubating conditions in 2-3 min after sevoflurane induction of anesthesia.

Acute pain management in children.

The greatest advance in pediatric pain medicine is the recognition that untreated pain is a significant cause of morbidity and even mortality after surgical trauma. Accurate assessment of pain in different age groups and the effective treatment of postoperative pain is constantly being refined; with newer drugs being used alone or in combination with other drugs continues to be explored. Several advances in developmental neurobiology and pharmacology, knowledge of new analgesics and newer applications of old analgesics in the last two decades have helped the pediatric anesthesiologist in managing pain in children more efficiently. The latter include administering opioids via the skin and nasal mucosa and their addition into the neuraxial local anesthetics. Systemic opioids, nonsteroidal anti-inflammatory agents and regional analgesics alone or combined with additives are currently used to provide effective postoperative analgesia. These modalities are best utilized when combined as a multimodal approach to treat acute pain in the perioperative setting. The development of receptor specific drugs that can produce pain relief without the untoward side effects of respiratory depression will hasten the recovery and discharge of children after surgery. This review focuses on the overview of acute pain management in children, with an emphasis on pharmacological and regional anesthesia in achieving this goal.

Postoperative pain management in children.

There is increased awareness of the need for effective postoperative analgesia in infants and young children. A multi-modal approach to preventing and treating pain usually is used. Mild analgesics, local and regional analgesia, and opioids when indicated, frequently are combined to minimize adverse effects of individual drugs or techniques.

A randomized controlled trial to evaluate S-Caine patch for reducing pain associated with vascular access in children.

BACKGROUND: A randomized, double-blinded trial was performed to evaluate the efficacy and safety of the S-Caine Patch (ZARS, Inc., Salt Lake City, UT), a eutectic mixture of lidocaine and tetracaine, for pain relief during venipuncture in children. METHODS: With institutional review board approval, parental consent, and patient assent, 64 children who were scheduled for medically indicated vascular access at two centers were randomly assigned (2:1) to receive either an S-Caine Patch or a placebo patch for 20 min before venipuncture procedures. The primary outcome measure was the child's rating of pain during venipuncture using the Oucher pain scale. Additional measures of efficacy included the blinded investigator's and an independent observer's four-point categorical scores. Variables were compared between treatments using Mantel-Haenszel summary chi-square tests or Pearson chi-square tests. RESULTS: The S-Caine Patch produced significantly greater pain relief compared with placebo (median Oucher scores of 0 vs. 60; P < 0.001). Fifty-nine percent of the children in the S-Caine Patch group reported no pain compared with 20% of the children in the placebo patch group. The investigator estimated that 76% of the children in the S-Caine Patch group experienced no pain during venipuncture versus 20% in the placebo patch group (P = 0.001). Independent observer ratings also favored the S-Caine Patchtrade mark (P < 0.001). Mild skin erythema (< 38%) and edema (< 2%) occurred with similar frequencies between the groups. CONCLUSION: This study demonstrated that a 20-min application of the S-Caine Patch is effective in lessening pain associated with venipuncture procedures. Adverse events after S-Caine Patch application were mild and transient.

A double-blind comparison of intravenous ondansetron and placebo for preventing postoperative emesis in 1- to 24-month-old pediatric patients after surgery under general anesthesia.

UNLABELLED: We assessed the efficacy and safety of ondansetron (0.1 mg/kg IV) prophylactically administered before surgery for prevention of postoperative vomiting (POV) in a double-blind, placebo-controlled study of 670 pediatric patients, 1- to 24-mo-old, undergoing elective surgery under general anesthesia. The study enrolled 335 children in each treatment group (ondansetron versus placebo). Significantly fewer children treated with ondansetron exhibited emesis or discontinued the study prematurely after surgery (ondansetron, 11%; placebo, 28%; odds ratio = 0.33; P < 0.0001). The number required to treat prophylactically with ondansetron to prevent POV was approximately six. Ondansetron treatment also resulted in fewer patients requiring rescue medication or assumed to have had rescue upon early discontinuation from the study during the postoperative period (ondansetron, 5%; placebo, 10%) and less emesis (0 of 6) after rescue medication when compared with placebo (7 of 21). The incidence of POV and other antiemetic effects of ondansetron were similar in children aged 1-12 mo and 13-24 mo and in children prospectively expected or not expected to require opioids as part of their anesthetic or analgesic management. Ondansetron was well tolerated; the incidence of adverse events considered possibly related to study drug was similar between treatment groups (ondansetron, 1.8%; placebo, 1.5%). IMPLICATIONS: This prospective, randomized, double-blind, placebo-controlled study establishes the efficacy and tolerability of IV ondansetron (0.1 mg/kg) in the prevention of postoperative emesis in 1- to 24-mo-old pediatric patients undergoing elective surgery under general anesthesia.

Propofol or midazolam do not reduce the incidence of emergence agitation associated with desflurane anaesthesia in children undergoing adenotonsillectomy.

BACKGROUND: The aim of the study was to determine if concurrent use of short-acting sedatives would decrease the incidence of emergence agitation associated with desflurane while preserving rapid recovery. METHODS: Sixty-nine children, aged 2-9 years, who were undergoing adenotonsillectomy, were randomly assigned to three groups: (i) intravenous midazolam 0.1 mg.kg-1; (ii) propofol 2 mg.kg-1; and (iii) control. An observer blind to anaesthetic technique assessed emergence times and behaviour. Data were compared using chi-squared and ANOVA. RESULTS: Midazolam initially decreased the incidence of emergence agitation but, in the postanaesthesia care unit, significant agitation was seen in all three groups. Emergence and complete recovery were delayed in groups 1 and 2. CONCLUSIONS: The concurrent use of midazolam or propofol did not reduce the incidence of emergence agitation but did delay emergence and recovery. These agents are not recommended for reducing emergence agitation in children receiving desflurane.

Clinical and biochemical effects of propofol EDTA vs sevoflurane in healthy infants and young children.

BACKGROUND: Propofol is frequently used for the induction and maintenance of anaesthesia in children aged 3 years and older. The present study compared the clinical and chemical effects of propofol containing disodium edetate (Diprivan) with that of sevoflurane in children younger than 3 years of age. METHODS: This was an open-label, comparative, parallel-group study. Fifty-six healthy children were randomly assigned to receive either propofol (n=28; mean age 14.7 months) or sevoflurane (n=28; mean age 13.2 months) for ambulatory surgical procedures. Anaesthesia was induced with nitrous oxide (60%), oxygen and sevoflurane (8%). In the propofol group, it was followed by an intravenous infusion of propofol at a rate of 200 microg.kg(-1).min(-1). For the sevoflurane group, anaesthesia was maintained with sevoflurane (1.5-2.5%). Haemodynamic measurements, recovery time and side-effects were recorded. Ionized calcium and magnesium concentrations in blood were measured. Statistical analysis was performed using ancova and the Fisher's exact test. RESULTS: The effects of propofol were similar to those of sevoflurane with respect to haemodynamic profile, recovery times (20 min vs 19.4 min) and side-effects (i.e. vomiting 10.7% vs 7.1%). Throughout the study, there were no significant differences between the mean ionized calcium and ionized magnesium concentrations in the two groups. CONCLUSIONS: In children younger than 3 years of age, propofol containing ethylenediaminetetraacetic acid has a similar profile to sevoflurane with respect to haemodynamic effects, recovery times, side-effects, ionized calcium and ionized magnesium levels.

Ketamine and midazolam is an inappropriate preinduction combination in uncooperative children undergoing brief ambulatory procedures.

BACKGROUND: We prospectively studied the effects of intramuscular (i.m.) ketamine alone, or combined with midazolam, on mask acceptance and recovery in young children who were uncooperative during induction of anaesthesia. METHODS: The Institutional Review Board (IRB) approval was obtained to study 80 children, 1-3 years, scheduled for bilateral myringotomies and tube insertion (BMT). Mask induction was attempted in all the children. Those who were uncooperative were randomly assigned to one of the four preinduction treatment groups: group I, ketamine 2 mg.kg(-1); group II, ketamine 2 mg.kg(-1) combined with midazolam 0.1 mg.kg(-1); group III, ketamine 2 mg.kg(-1) with midazolam 0.2 mg.kg(-1); or group IV, ketamine 1 mg.kg(-1) with midazolam 0.2 mg.kg(-1). Anaesthesia was continued with nitrous oxide and halothane by facemask. RESULTS: Children in all treatment groups achieved satisfactory sedation in less than 3 min following the administration of the preinduction drug(s). Compared with patients who received halothane induction (comparison group), the use of ketamine alone did not significantly (P > 0.0167, a Bonferroni corrected significance level) delay recovery and discharge times (18.8 +/- 2.5 and 82.5 +/- 30.7 min vs 12.6 +/- 4.6 and 81.0 +/- 33.8 min, P = 0.030 and P = 0.941, respectively). Patients who received ketamine/midazolam combinations, however, had significantly longer recovery and discharge times vs halothane (32.3 +/- 14.0 and 128.0 +/- 36.6 min, P = 0.001, P = 0.007, respectively). These times were so clinically unacceptable, that the study had to be terminated with only 17 patients receiving study drugs. CONCLUSIONS: It is concluded that ketamine/midazolam combination is not appropriate for preinduction of anaesthesia in paediatric ambulatory patients because of unacceptably prolonged recovery and delayed discharge times.

The effect of fentanyl on the emergence characteristics after desflurane or sevoflurane anesthesia in children.

UNLABELLED: Desflurane and sevoflurane anesthesia are associated with emergence agitation in children. In this study, we examined the effect of a single intraoperative dose of fentanyl on emergence characteristics in children undergoing adenoidectomy. One hundred children, 2-7 yr old, were randomly assigned to receive desflurane or sevoflurane for maintenance of general anesthesia after an inhaled induction with sevoflurane and a 2.5 microg/kg dose of fentanyl. An observer blind-ed to the anesthetic technique assessed the times to achieve emergence, extubation and recovery criteria, as well as emergence behaviors. The results showed a similar incidence of severe emergence agitation after general anesthesia with desflurane (24%) and sevoflurane (18%). Times to achieve extubation and postanesthesia care unit discharge criteria were shorter with desflurane than with sevoflurane. With this technique, desflurane allows for a more rapid emergence and recovery than sevoflurane. In children receiving desflurane or sevoflurane, the concurrent use of fentanyl in a dose of 2.5 microg/kg results in a small incidence of emergence agitation. IMPLICATIONS: The concurrent use of fentanyl in a dose of 2.5 microg/kg in children receiving desflurane or sevoflurane results in a low incidence of emergence agitation. Desflurane allows for a more rapid emergence and recovery than sevoflurane.

Caudal anesthesia in children: effect of volume versus concentration of bupivacaine on blocking spermatic cord traction response during orchidopexy.

UNLABELLED: In this study we compared the intensity and level of caudal blockade when two different volumes and concentrations of a fixed dose of bupivacaine were used. Fifty children, 1-6 yr old, undergoing unilateral orchidopexy received a caudal block with a fixed 2 mg/kg dose of bupivacaine immediately after the induction. Group 1 (n = 23) received 0.8 mL/kg of 0.25% bupivacaine, whereas Group 2 (n = 27) received 1.0 mL/kg of 0.2% bupivacaine. Epinephrine 1:400,000 and 0.1 mL of sodium bicarbonate per 10 mL of local anesthetic solution were added. There were no statistically significant differences between the two groups in their anesthesia, surgery, recovery, and discharge times. Fifteen patients (65.2%) in Group 1 required an increase in inspired halothane concentration to block hemodynamic and/or ventilatory response during spermatic cord traction, as compared with 8 patients (29.6%) in Group 2 (P = 0.022). In the recovery room, four (17.4%) patients in Group 1 required rescue treatment with fentanyl, versus two (7.4%) in Group 2 (P = 0.372). In children undergoing orchidopexy, a caudal block with a larger volume of dilute bupivacaine is more effective than a smaller volume of the standard 0.25% solution in blocking the peritoneal response during spermatic cord traction, with no change in the quality of postoperative analgesia. IMPLICATIONS: In children undergoing orchidopexy, a caudal block with a larger volume of dilute bupivacaine is more effective than a smaller volume of the more concentrated solution in blocking the peritoneal response during spermatic cord traction, with no change in the quality of postoperative analgesia.

Rapid emergence does not explain agitation following sevoflurane anaesthesia in infants and children: a comparison with propofol.

BACKGROUND: Emergence agitation in children is frequently associated with the use of the new highly insoluble volatile anaesthetics. Rapid emergence has been cited as one of the possible causes. Propofol also permits rapid emergence from general anaesthesia but is not associated with agitation. METHODS: The emergence characteristics of children receiving sevoflurane and propofol anaesthesia were examined. After induction with sevoflurane, 53 children, aged 2-36 months, who were undergoing ambulatory surgery, were randomized to receive maintenance anaesthesia with either sevoflurane or propofol. Introperative analgesia with either 2 micro g x kg-1 of intravenous fentanyl or a caudal block with 0.25% bupivacaine was supplied according to surgical procedure. An observer blinded to anaesthetic technique recorded the time to achieve extubation and recovery and assessed emergence behaviour. Data were analysed using Wilcoxon scores, Kruskal-Wallis test, chi-square and multiple regression analysis. RESULTS: The results showed that the time to extubation and recovery were similar between the two study groups, but that emergence agitation was significantly higher in the sevoflurane group compared with the propofol group. No relationship between analgesic technique and agitation scores was found. CONCLUSIONS: Although both sevoflurane and propofol allow for rapid emergence from general anaesthesia, only sevoflurane is associated with a high incidence of emergence agitation in infants and young children. Rapid emergence does not fully explain this phenomena.

Auscultation of bilateral breath sounds does not rule out endobronchial intubation in children.

We performed orotracheal intubation in 153 consecutive pediatric patients undergoing cardiac catheterization. Auscultation of bilateral breath sounds was confirmed. By fluoroscopy, the tip of the endotracheal tube (ETT) was seen in the right mainstem bronchus in 18 patients (11.8%) and in a low position, defined as within 1 cm above the carina, in 29 patients (19.0%). All of the 18 patients with right mainstem intubation were children <120 mo of age, and 7 were infants <12 mo of age (Fisher's exact test; P = 0.013). The age, weight, and ETT size for children who had endobronchial and low tracheal positions were significantly (P < 0.001) less than for those who had midtracheal positions. The failure to diagnose mainstem intubation by auscultation alone may be related to the use of the Murphy eye ETT, which reduces the reliability of chest auscultation in detecting endobronchial intubation. Suggested measures for preventing endobronchial intubation include maintaining increased awareness of the imperfection or lack of accuracy of the auscultatory method, assessing insertion depth by checking the length scale on the tube, and minimizing the patient's head and neck movement after intubation. When extreme flexion or extension of the neck is expected after ETT insertion, the resultant change in ETT final position must be anticipated and taken into consideration when deciding on the depth of ETT insertion. This approach resulted in a decrease in improper tube positioning from 20% when the study was initiated to 7.1% in the last 98 patients.

A comparison of three doses of a commercially prepared oral midazolam syrup in children.

UNLABELLED: Midazolam is widely used as a preanesthetic medication for children. Prior studies have used extemporaneous formulations to disguise the bitter taste of IV midazolam and to improve patient acceptance, but with unknown bioavailability. In this prospective, randomized, double-blinded study we examined the efficacy, safety, and taste acceptability of three doses (0.25, 0.5, and 1.0 mg/kg, up to a maximum of 20 mg) of commercially prepared Versed((R)) syrup (midazolam HCl) in children stratified by age (6 mo to <2 yr, 2 to <6 yr, and 6 to <16 yr). All children were ASA class I-III scheduled for elective surgery. Subjects were continuously observed and monitored with pulse oximetry. Ninety-five percent of patients accepted the syrup, and 97% demonstrated satisfactory sedation before induction. There was an apparent relationship between dose and onset of sedation and anxiolysis (P < 0.01). Eight-eight percent had satisfactory anxiety ratings at the time of attempted separation from parents, and 86% had satisfactory anxiety ratings at face mask application. The youngest age group recovered earlier than the two older age groups (P < 0.001). There was no relationship between midazolam dose and duration of postanesthesia care unit stay. Before induction, there were no episodes of desaturation, but there were two episodes of nausea and three episodes of emesis. At the time of induction, during anesthesia, and in the postanesthesia care unit, there were several adverse respiratory events. Oral midazolam syrup is effective for producing sedation and anxiolysis at a dose of 0.25 mg/kg, with minimal effects on respiration and oxygen saturation even when administered at doses as large as 1.0 mg/kg (maximum, 20 mg) as the sole sedating medication to healthy children in a supervised clinical setting. IMPLICATIONS: Commercially prepared oral midazolam syrup is effective in producing sedation and anxiolysis in doses as small as 0.25 mg/kg; there is a slightly faster onset with increasing the dose to 1.0 mg/kg. At all doses, 97% of patients demonstrated satisfactory sedation, whereas 86% demonstrated satisfactory anxiolysis when the face mask was applied.