Successful navigation of late career transitions.

The purpose of this educational review was to describe the challenges that may face the anesthesiologist near the end of their career and to propose strategies that will enable the individual to continue to be a productive and valued member of their Department, both clinically and by other contributions.

From the Journal archives: Epidural anesthesia in young children: what have we learned in the past 60 years?

UNLABELLED: Francis G. Ruston MD CITATION: Ruston FG. Epidural anaesthesia in infants and children. Can Anaesth Soc J 1954: 1: 37-44. PURPOSE: The author describes the use of single-shot epidural anesthesia in a series of 44 infants and children. The patients were anesthetized in hospitals in Hamilton, Ontario from 1949 until the time of publication in 1954. The study aimed to describe the indications and efficacy of this technique as well as any apparent complications. A detailed description of the management of these patients was given, including many tips and suggestions that are still applicable in 2013. PRINCIPAL FINDINGS: Seventy-seven infants and children received epidural anesthesia for a variety of procedures, particularly for pyloric stenosis. Forty-four of the procedures were carried out by the author. All patients survived, apart from one child who died of recurrent intestinal obstruction unrelated to the anesthetic. It was found, after some experience, that the sitting position was preferable for epidural needle insertion. Use of the hanging drop technique for identification of the epidural space proved to be simple and reliable. Surgical conditions were found to be excellent and relaxation was profound; however, some sedation was often required to obtain optimal conditions for surgery. The surgeons became sold on the technique and began to request an epidural on a regular basis. CONCLUSIONS: Epidural anesthesia in infants and young children is effective for a variety of procedures below the diaphragm, even in moribund patients.

Effect of dexamethasone on postoperative morbidity after dental rehabilitation in children.

PURPOSE: Dexamethasone reduces postoperative morbidity after adenotonsillectomy, strabismus surgery, and third molar extraction. Our hypothesis was that dexamethasone would reduce pain and other morbidity in children undergoing dental surgery for up to 24 hr postoperatively. METHODS: A triple-blinded, randomized, controlled trial was carried out on 200 children undergoing prolonged dental rehabilitation under general anesthesia. Subjects were randomized into two groups: group D, given dexamethasone 0.3 mg·kg(-1); group S, given normal saline. The primary outcome measure was pain over 24 hr as evaluated by a parental 0-10 numerical rating scale (NRS). Key secondary outcomes included oral intake on a four-point scale at 24 hr and the overall incidence of postoperative vomiting (POV). Analysis for the primary outcome consisted of comparison of means in the NRS with the Wilcoxon rank sum test and for occurrence of POV with Fisher's test. RESULTS: After eliminating 22 subjects for protocol violations and withdrawals, 178 subjects were analyzed. There was no significant difference in pain scores (NRS) at 24 hr or the worst NRS experienced over the preceding 24 hr. There was no difference in the quality of oral intake between the groups. There was a significant difference in the percentage of patients who vomited during the first 24 hr: eight of 91 in group S and one of 87 in group D. Therefore, 7.74% more vomited in group S (P = 0.045), with a 95% confidence interval of 0.32 to15.16 for the difference in percentages. CONCLUSIONS: Dexamethasone, 0.3 mg·kg(-1), did not reduce pain over 24 hr in healthy children undergoing dental rehabilitation under general anesthesia. The quality of oral intake was also unaffected by dexamethasone at 24 hr. Dexamethasone did produce a significant reduction in postdischarge vomiting, beyond the incidence found with ondansetron alone.

Fluid replacement in craniofacial pediatric surgery: normal saline or ringer's lactate?

INTRODUCTION: Pediatric craniofacial surgery requires large amounts of intravenous fluid replacement that may alter the ionic composition of body compartments. Normal (0.9%) saline (NS) and Ringer's lactate (RL) solutions are commonly used, with different advantages and disadvantages. Our hypothesis was that there would be more acidosis with NS but with no advantage of NS over RL regarding the incidence of hyponatremia. Our objective was to determine whether acid-base and electrolyte outcomes could guide fluid management in this group of patients. METHODS: A retrospective study of 122 children younger than 5 years who underwent craniofacial surgery was performed: 63 received only NS (NS group) and 59 received RL (RL group). Blood gases, plasma sodium, and potassium concentrations were analyzed during 2 different periods: 1 to 2 hours from anesthetic induction (P-1) and 2 to 4 hours from anesthetic induction (P-2). Statistical comparisons were made with χ test and t-test, as appropriate. RESULTS: Acidosis was more frequent in NS group than in RL patients during P-1 and P-2: 66% and 80% in the NS group versus 26% and 37% in the RL group. Severe acidosis (pH ≤ 7.25) was also more frequently in those receiving NS (39%) than RL (8%); and so was a base excess of -5 or less: NS = 53% and RL = 16%. The incidence of hyponatremia (Na < 135 mmol/L) was similar in both groups: 40% (NS) and 26% (RL) during P-1 and 52% (NS) and 50% (RL) during P-2. CONCLUSIONS: In young children undergoing craniofacial surgery, RL may be a preferred crystalloid over NS because metabolic acidosis is less frequent, with no increased incidence of hyponatremia.

Anesthesia can be safely provided for children in a high-field intraoperative magnetic resonance imaging environment.

OBJECTIVES: To describe the challenges associated with providing safe anesthesia and perioperative care for children in a remote intraoperative magnetic resonance (iMR) operating room (OR) and to identify perioperative anesthesia outcomes, including adverse events related to the iMR environment. BACKGROUND: Increasingly, children undergo neurosurgical procedures in a high-field iMR OR. We describe a 10-year experience of providing anesthesia for children in this environment with a mobile 1.5-Tesla magnet. METHODS: A 10-year retrospective analysis was conducted of children who underwent neurosurgical procedures in a high-field mobile iMR OR. Primary outcomes related to perioperative adverse events and recovery profiles. Results were expressed as mean ± sd or median (range), as appropriate. RESULTS: One hundred and five procedures were performed on 98 children, aged 4 months-18 years, weighing 6-112 kg. The commonest two diagnostic categories were tumor (n = 52) and seizures (n = 27). Median anesthetic time was 439 (185-710) mins. There were no significant adverse events related to the iMR environment. The mean postanesthetic care unit admission temperature was 37 ± 0.9°C and the mean modified Aldrete Score at 30 mins was 7.2 ± 0.9. Two patients experienced seizures in the immediate postoperative period, readily controlled with propofol. There was one breach of MR safety protocol, and no adverse events related to patient transport. CONCLUSIONS: Anesthesia and perioperative care of children in an iMR setting were associated with a very low incidence of complications, despite the duration of the procedures involved. Such success depends upon a cohesive team-based approach.

Vitamin D concentrations among healthy children in Calgary, Alberta.

OBJECTIVE: To examine the relationship between serum vitamin D concentrations, dietary intake and body mass index among healthy children living in Calgary, Alberta. METHODS: The present cross-sectional study included healthy children two to 13 years of age who presented to the Alberta Children's Hospital for elective surgery during a 12-month period. Data including the child's weight, height, age, sex, ethnicity, dietary intake, use of vitamin supplements, physical activity and time spent outdoors were collected. Serum concentrations of 25-hydroxyvitamin D (25[OH]D) were measured using commercial immunoradiometric assay kits. RESULTS: Serum 25(OH)D concentrations were available for 1442 of 1862 participants, of whom 862 (59.8%) were boys. The mean (± SD) serum 25(OH)D concentration was 86.1±35.1 nmol/L (range 10 nmol/L to 323 nmol/L). Five hundred thirty-nine (37.4%) participants had insufficient vitamin D status (25[OH]D between 25 nmol/L and lower than 75 nmol/L), and vitamin D deficiency (25[OH]D 25 nmol/L or lower) was present in 29 subjects (2.0%). Children in the older age group (nine to 13 years) were more likely to have suboptimal vitamin D (P<0.001). Other risk factors significantly associated with suboptimal vitamin D status included overweight or obesity, nonwhite ethnicity, winter months, dietary vitamin D intake of less than 200 IU/day and less time spent outdoors. CONCLUSION: A high rate of suboptimal vitamin D concentrations was observed among the participants. Beyond promoting a vitamin D-enriched diet, physicians should also consider the body mass index and other risk factors to determine the optimal vitamin D intake for children living in the area studied.

Evidence-based clinical update: Which local anesthetic drug for pediatric caudal block provides optimal efficacy with the fewest side effects?

PURPOSE: The purpose of this evidence-based clinical update is to identify the best evidence when selecting a long-acting local anesthetic agent for single-shot pediatric caudal anesthesia in children. METHODS: A structured literature search was conducted using PubMed and Medline (OVID) using the terms "caudal" and combinations of at least two of "bupivacaine", "ropivacaine", and "levobupivacaine". The search limits included "randomized controlled trials" (RCTs), "meta-analysis", "evidence-based reviews" or "reviews", "human", and "all child: 0-18 yr". Seventeen RCTs were identified that concerned single-shot pediatric caudal anesthesia with at least two of the three drugs in question. Data were extracted for the areas of clinical efficacy and side effects. Study findings were assigned levels of evidence, and grades of recommendation were made according to Centre for Evidence-Based Medicine criteria. RESULTS: The three drugs investigated were found to be equivalent in terms of efficacy. Evidence showed bupivacaine with the highest incidence of motor block and ropivacaine with the lowest. Adverse effects were rare and unrelated to the choice of drug. There were no serious adverse events. CONCLUSION: None of the three agents was shown to be superior in terms of efficacy. Bupivacaine is preferred if motor block is desired, ropivacaine is preferred if motor block is to be minimized. Adverse effects in human studies are rare, mild, and unrelated to the choice of drug. Despite encountering the absence of serious adverse events in each of the studies reviewed, it is noted that animal studies suggest a safer profile with ropivacaine or levobupivacaine than with bupivacaine.

Anesthetic management for pediatric strabismus surgery: Continuing professional development.

PURPOSE: Strabismus surgery is one of the most common pediatric ophthalmic procedures. The purpose of this continuing professional development module is to update physicians on the anesthetic considerations of pediatric patients undergoing strabismus surgery. PRINCIPAL FINDINGS: The preoperative assessment is important, as patients undergoing strabismus surgery may have an associated neuromuscular disorder, congenital syndrome, or cardiac disease. Malignant hyperthermia is no longer considered as being an issue associated with strabismus. The laryngeal mask airway is used frequently and has been shown as being associated with a low incidence of complications in strabismus surgery. The anesthesia technique can be adapted to decrease the incidence of the oculocardiac reflex and the oculorespiratory reflex, and the use of anticholinergic prophylaxis remains debatable. Since patients are at high risk for postoperative nausea and vomiting (PONV), combination anti-emetic therapy is recommended using dexamethasone and ondansetron. Metoclopramide was not found to provide additional benefit when combined with other anti-emetics. Droperidol is effective, but there remains a black box warning for dysrhythmias. Effective analgesics in this patient population include acetaminophen, nonsteroidal anti-inflammatory drugs, peribulbar blocks, and subtenon blocks. Topical tetracaine drops have demonstrated mixed results, and topical nonsteroidal anti-inflammatory drops were found not to be effective. The use of opioids should be minimized due to the increased incidence of PONV. CONCLUSIONS: To provide optimal care for the pediatric patient undergoing strabismus surgery, it is important to understand the unique anesthetic considerations for strabismus surgery and to appreciate how each decision regarding the anesthetic technique can alter these considerations.

Application of intraoperative high-field magnetic resonance imaging in pediatric neurosurgery.

OBJECT: Over the past decade, the use of intraoperative MR (iMR) imaging in the pediatric neurosurgical population has become increasingly accepted as an innovative and important neurosurgical tool. The authors summarize their experience using a mobile 1.5-T iMR imaging unit with integrated neuronavigation with the goal of identifying procedures and/or pathologies in which the application of this technology changed the course of surgery or modified the operative strategy. METHODS: A database has been prospectively maintained for this patient population. The authors reviewed the hospital charts and imaging results for all patients in the database. This review revealed 105 neurosurgical procedures performed in 98 children (49 male and 49 female) between March 1998 and April 2008. Intradissection (ID) and/or quality assurance images were obtained at the discretion of the surgeon. RESULTS: The median age at surgery was 12 years (4 months-18 years). One hundred intracranial and 5 spinal procedures were performed; 22 of these procedures were performed for recurrent pathology. Surgical planning scans were obtained for 102 procedures, and neuronavigation was used in 93 patients. The greatest impact of iMR imaging was apparent in the 55 procedures to resect neoplastic lesions; ID scans were obtained in 49 of these procedures. Further surgery was performed in 49% of the procedures during which ID scans had been obtained. A smaller proportion of ID scans in the different cranial pathology groups (5 of 21 epilepsy cases, 4 of 9 vascular cases) resulted in further resections to meet the surgical goal of the surgeon. Two ID scans obtained during 5 procedures for the treatment of spinal disease did not lead to any change in surgery. Postoperative scans did not reveal any acute adverse events. There was 1 intraoperative adverse event in which a Greenberg retractor was inadvertently left on during ID scanning but was removed after the scout scans. CONCLUSIONS: The application of iMR imaging in the pediatric neurosurgical population allows, at minimum, the opportunity to perform less invasive surgical exposures. Its potential is greatest when its high-quality imaging ability is coupled with its superior neuronavigation capabilities, which permits tracking of the extent of resection of intracranial tumors and, to a lesser extent, other lesions during the surgical procedure.

Glutamine decreases inflammation in infant rat endotoxemia.

Glutamine may have benefits during neonatal sepsis, but its effects on systemic inflammation are unknown. Our aim was to determine whether glutamine affects inflammation in neonatal endotoxemia. Eleven-day rat pups were given intraperitoneal injections of saline (control; C), endotoxin (300 microg/g Escherichia coli lipopolysaccharide) (E), saline with glutamine (2 mmol/g; G), or endotoxin with glutamine (EG). Animals were killed after 2 or 6 hours. Plasma glutamine (mmol/L) was measured enzymatically, and both tumor necrosis factor alpha (pg/mL) and interleukin 10 (IL-10) were measured by enzyme-linked immunosorbent assay. Results, expressed as mean +/- SEM, were analyzed by analysis of variance. Endotoxemia caused a rapid significant decrease in plasma glutamine at 2 hours (C, 0.73 +/- 0.06; E, 0.32 +/- 0.07; mean difference, 0.41 [95% confidence interval {CI, 0.17-0.64}]; P < .001), which was prevented by intraperitoneal glutamine (EG, 0.59 +/- 0.04; mean difference vs E, 0.27 mmol/L [95% CI, 0.03-0.50]; P < .05), indicating glutamine absorption, whereas CG animals had a plasma glutamine of 0.82 +/- 0.07. Tumor necrosis factor alpha was greatly increased by 2-hour endotoxemia (C, 27 +/- 7; E, 2247 +/- 43; mean difference, 2220 pg/mL [95% CI, 2012-2429]; P < .001), and this increase was partly prevented by glutamine (EG, 1991 +/- 91; P < .05 vs E; mean difference, 256; 95% CI, 47-465; P < .05). The effect of glutamine was more pronounced at 6 hours (C, 32 +/- 27; E, 799 +/- 193; EG, 219 +/- 75, C vs E mean difference, 767; 95% CI, 346-1188; P < .001; E vs EG mean difference, 580; 95% CI, 159-1001; P < .01). The IL-10 levels were also greatly increased by 2-hour endotoxemia (C = 55 +/- 21, E = 2429 +/- 58, EG = 1989 +/- 177; C vs E mean difference, 2374; 95% CI, 2740-2008; P < .001; E vs EG mean difference, 440; 95% CI, 74-807; P < .05). Glutamine administration partially prevents the sepsis-induced fall in plasma glutamine levels and reduces the concentration of both proinflammatory and antiinflammatory cytokines.

[Comparison of laryngeal mask airway (LMA)- Proseal and the LMA-Classic in ventilated children receiving neuromuscular blockade].

PURPOSE: To determine whether a functional difference exists between the size 2 laryngeal mask airway (LMA)-Classic (CLMA) and LMA-Proseal (PLMA) in anesthetized children who have received neuromuscular blockade. Airway leak during intermittent positive pressure ventilation (IPPV) and adequacy of fibreoptic laryngeal view were the primary study outcomes. METHODS: A randomized, controlled, single-blinded study of 51 ASA I or II children weighing 10-20 kg was undertaken. The anesthetic technique was standardized. Following insertion of the LMA and cuff inflation to 60 cm H(2)O, we measured oropharyngeal leak pressure and gastric insufflation and leak fraction during IPPV, and evaluated the adequacy of fibreoptic view. RESULTS: Oropharyngeal leak pressure measured by neck auscultation was higher for the PLMA compared to the CLMA (23.7 vs 16.5 cm H(2)O, P = 0.009) but, when measured by the inspiratory hold maneuver was not significantly different (24.8 vs 20.3 cm H(2)O, respectively, P = 0.217). Leak fraction values were similar for the CLMA and the PLMA (21.2%. vs 13.3%, respectively, P = 0.473). A satisfactory view of the larynx was obtained more frequently in the PLMA group (21/25 vs 10/25, P = 0.003). Gastric insufflation during leak determination was more common with the CLMA (12/26 vs 2/25 CLMA vs PLMA, respectively, P = 0.006). CONCLUSION: In children undergoing IPPV with neuromuscular blockade, the size 2 PLMA is associated with a higher leak pressure by auscultation and less gastric insufflation compared to the CLMA. Leak pressures assessed by manometric stability are similar with these two devices. The improved fibreoptic view of the larynx through the PLMA may be advantageous for bronchoscopy.

Evidence-based clinical update: does premedication with oral midazolam lead to improved behavioural outcomes in children?

PURPOSE: The purpose of this evidence-based clinical update was to identify the best evidence to determine if behavioural outcomes are improved in children after oral midazolam premedication. METHODS: A literature search was conducted using both PubMed and OVID programs, utilizing the terms "midazolam", and either "premedication" or "preoperative treatment". Search limits that were employed included randomized controlled trials (RCTs), English language, human studies, children aged 0-18 yr, and publication dates 1990 - present (January 2006). A review of the 171 abstracts obtained was undertaken and, of these, 30 papers were identified that concerned oral midazolam in children prior to general anesthesia, and that involved a RCT with a placebo or control arm. These studies were assigned levels of evidence, and grades of recommendation were made according to Centre for Evidence-Based Medicine criteria. RESULTS: Oral midazolam premedication in children was found to reduce the anxiety associated with separation from parents/guardians, and with induction of anesthesia. Recovery times are not significantly delayed. There is no consistent evidence to suggest a reduction in the phenomenon of emergence agitation. Evidence suggesting an improvement in behavioural outcomes at home is also inconsistent. CONCLUSION: Premedication with midazolam 0.5 mg x kg(-1) po administered 20-30 min preoperatively, is effective in reducing both separation and induction anxiety in children (grade A recommendation), with minimal effect on recovery times. However improved postoperative behavioural outcomes in the postanesthesia care unit, or at home cannot be predicted on a consistent basis.

The ankle clonus test is not a clinically useful measure of spinal cord integrity in children.

PURPOSE: Bilateral flexion-induced ankle clonus has been proposed as a test of spinal cord integrity during anesthesia for scoliosis surgery. The purpose of this study was to establish the reliability of this test in normal children emerging from volatile anesthesia. A secondary objective was to determine if there was a difference in the validity of this test with either sevoflurane or isoflurane anesthesia. METHODS: In a randomized, prospective blinded clinical trial, 32 healthy children aged three to 13 yr, were randomized to receive either isoflurane (Group I, n = 15) or sevoflurane (Group S, n = 17) for maintenance of anesthesia during dental restorative surgery. During emergence, an observer, blinded to group allocation, recorded ankle clonus scores (number of beats to a maximum of 5 on each side) at 60-sec intervals until tracheal extubation. End-tidal anesthetic concentration was measured contemporaneously. RESULTS: Non-sustained ankle clonus was elicited in a majority of children during emergence: 13 (87%) patients in Group I and 15 (88%) in Group S demonstrated at least non-sustained or unilateral clonus. However, bilateral sustained (> 5 beats.min(-1)) ankle clonus occurred in only four (27%) patients in Group I and four (24%) patients in Group S (P = 0.83). CONCLUSION: We conclude that the specificity of the ankle clonus test is too low to be clinically useful as a measure of spinal cord integrity in children, both when isoflurane and sevoflurane are used as the primary anesthetic agent.

Patient selection in ambulatory anesthesia - an evidence-based review: part I.

PURPOSE: To identify and characterize the evidence supporting decisions made in the care of patients with selected medical conditions undergoing ambulatory anesthesia and surgery. Conditions highlighted in this review include: the elderly, heart transplantation, hyper-reactive airway disease, coronary artery disease, and obstructive sleep apnea. SOURCE: A structured search of MEDLINE (1966-2003) was performed using keywords for ambulatory surgery and patient condition. Selected articles were assigned a level of evidence using Centre for Evidence Based Medicine (CEBM) criteria. Recommendations were also graded using CEBM criteria. PRINCIPAL FINDINGS: The elderly may safely undergo ambulatory surgery but are at increased risk for hemodynamic variation in the operating room. The heart transplant recipient is at increased risk of coronary artery disease and renal insufficiency and should undergo careful preoperative evaluation. The patient with reactive airway disease is at increased risk of minor respiratory complications and should be encouraged to quit smoking. The patient with coronary artery disease and recent myocardial infarction may undergo ambulatory surgery without stress testing if functional capacity is adequate. The patient with obstructive sleep apnea is at increased risk of difficult tracheal intubation but the likelihood of airway obstruction and apnea following ambulatory surgery is unknown. CONCLUSION: Ambulatory anesthesia is infrequently associated with adverse outcomes, however, knowledge regarding specific patient conditions is of generally low quality. Few prospective trials are available to guide management decisions.

Patient selection in ambulatory anesthesia - an evidence-based review: part II.

PURPOSE: This is the second of two reviews evaluating the management of patients with selected medical conditions undergoing ambulatory anesthesia and surgery. Conditions highlighted in this review include: diabetes mellitus; morbid obesity; the ex-premature infant; the child with an upper respiratory infection; malignant hyperthermia; and the use of monoamine oxidase inhibitors. SOURCE: Medline search strategies and the framework for the evaluation of clinical evidence are presented in Part I. PRINCIPAL FINDINGS: Diabetes mellitus has not been linked with adverse events following ambulatory surgery. The morbidly obese patient is at an increased risk for minor respiratory complications in the perioperative period but these events do not increase unanticipated admissions. The ex-premature infant may be considered for ambulatory surgery if post-conceptual age is > 60 weeks and hematocrit is > 30%. The child with a recent upper respiratory tract infection is at an increased risk for perioperative respiratory complications, particularly if endotracheal intubation is required. Patients with malignant hyperthermia may undergo outpatient surgery but require four hours of postoperative temperature monitoring. Sporadic cases of drug interactions have been reported when meperidine and indirect-acting catecholamines are administered in the presence of monamine oxidase inhibitors. Ambulatory anesthesia and surgery is safe if these combinations of drugs are avoided. CONCLUSION: Ambulatory anesthesia can be performed in, and is being offered to, a variety of patients with significant coexistent disease. In many cases there is little evidence documenting the outcomes expected in such patients. Prospective observational and interventional trials are required to better define perioperative management.