Comparison of enflurane, halothane, and isoflurane for diagnostic and therapeutic procedures in children with malignancies

Incidence and Associated Factors of Laryngospasm among Pediatric Patients Who Underwent Surgery under General Anesthesia, in University of Gondar Compressive Specialized Hospital, Northwest Ethiopia, 2019: A Cross-Sectional Study

Introduction

Laryngospasm is a glottis closure due to reflex constriction of the laryngeal muscles. It can occur at any phase of the anesthetic. Different studies have been done previously with various results and indicative values which initiated us to do this research. This study aimed to assess the incidence and associated factors of laryngospasm among pediatric patients who underwent surgery under general anesthesia (GA).

Methods

Institution-based, cross-sectional study was conducted on pediatric patients from February to August, 2019, in University of Gondar Comprehensive Specialized Hospital (UOGCSH). Data were entered and analyzed with SPSS version 20. Variables with P value less than <0.2 in bivariate analysis were fitted into the multivariable logistic regression analysis to identify factors associated with laryngospasm. Both crude and adjusted odds ratio with 95% CI were calculated to show strength of association. In multivariable analysis, P value of <0.05 was considered as statistically significant.

Results

The incidence of laryngospasm among pediatric patients who underwent surgery under GA was 57 (18.4%). Of this, 34 (59.6%), 12 (21.1%), and 11 (19.3%) happened during emergence, maintenance, and induction phases of GA, respectively. In multivariable analysis, airway anomalies (AOR: 14.64, 95% CI: 1.71, 125.04), secretion (AOR: 2.45, 95% CI: 1.19, 5.06), attempts of airway devices (AOR: 2.47, 95% CI: 1.16, 5.22), upper respiratory tract infection (AOR: 2.91, 95% CI: 1.008, 8.41), and inadequate depth of anesthesia (AOR: 7.92, 95% CI: 2.7, 23.22) were significantly associated with incidence of laryngospasm.

Conclusions

Laryngospasm can occur at any phase of the anesthetic. At UOGCSH, the overall rate of laryngospasm was 18.4%, with the vast majority of episodes occurring on emergence. Inadequate depth of anesthesia, URTI, airway anomalies, multiple attempts of airway devices, and oropharyngeal secretion were predictors of laryngospasm. So, added vigilance is needed in patients with URTI, airway anomalies, or those who require multiple attempts at airway device insertion. Prompt clearing of airway secretions and adequate depth of anesthesia may help to prevent laryngospasm. Since the majority of our patients received an IV induction, endotracheal intubation, and maintenance with halothane, caution must be taken in extrapolating these results to other patient populations.

Low dose isoflurane exerts opposing effects on neuronal network excitability in neocortex and hippocampus

The anesthetic excitement phase occurring during induction of anesthesia with volatile anesthetics is a well-known phenomenon in clinical practice. However, the physiological mechanisms underlying anesthetic-induced excitation are still unclear. Here we provide evidence from in vitro experiments performed on rat brain slices that the general anesthetic isoflurane at a concentration of about 0.1 mM can enhance neuronal network excitability in the hippocampus, while simultaneously reducing it in the neocortex. In contrast, isoflurane tissue concentrations above 0.3 mM expectedly caused a pronounced reduction in both brain regions. Neuronal network excitability was assessed by combining simultaneous multisite stimulation via a multielectrode array with recording intrinsic optical signals as a measure of neuronal population activity.

Anesthetic and perioperative risk in the patient with Ataxia-Telangiectasia

OBJECTIVES/AIM

To report our relatively large experience with perioperative care for patients with Ataxia-Telangiectasia (A-T) and to identify the nature and frequency of complications.

BACKGROUND

Ataxia-Telangiectasia is a rare autosomal recessive genetic disorder resulting in progressive multisystem degeneration and characteristic findings including complex neurodegeneration, immunodeficiency, increased risk of malignancy, and lung disease. Anecdotal reports have suggested high perioperative morbidity in patients with A-T, but few data exist.

METHODS/MATERIALS

The Ataxia-Telangiectasia Clinical Center database was cross-referenced with operative records between 1995 and 2009 to identify patients with perioperative A-T, and medical records were reviewed for preoperative history, management techniques, and complications.

RESULTS

Twenty-one patients with A-T underwent 34 anesthetics during the study period. The median age was 12.5 years (range 6-33 years). Common comorbidities included neurologic (100%), pulmonary (68%), immunologic (50%), oncologic (47%), and gastroenterologic (35%) disorders. Supplemental oxygen was required on postanesthesia care unit discharge for 24% of patients with a maximal duration of 24 h. Although mild postoperative hypothermia was relatively common (44% of anesthetics), there were no major complications, no unplanned admissions, and no mortality in this series.

CONCLUSIONS

Although limited by its retrospective nature, this is the first series describing perioperative risk for patients with A-T. Our results indicate that general anesthesia, airway manipulation, and perioperative mechanical ventilation may be tolerated with only minor postoperative anesthetic concerns. Perioperative providers should be aware of the complex multisystem medical concerns that may arise in these patients.

Laryngospasm: review of different prevention and treatment modalities

Laryngospasm is a common complication in pediatric anesthesia. In the majority of cases, laryngospasm is self-limiting. However, sometimes laryngospasm persists and if not appropriately treated, it may result in serious complications that may be life-threatening. The present review discusses laryngospasm with the emphasis on the different prevention and treatment modalities.

Crisis management during anaesthesia: laryngospasm

BACKGROUND

Laryngospasm is usually easily detected and managed, but may present atypically and/or be precipitated by factors which are not immediately recognised. If poorly managed, it has the potential to cause morbidity and mortality such as severe hypoxaemia, pulmonary aspiration, and post-obstructive pulmonary oedema.

OBJECTIVES

To examine the role of a previously described core algorithm "COVER ABCD-A SWIFT CHECK", supplemented by a specific sub-algorithm for laryngospasm, in the management of laryngospasm occurring in association with anaesthesia.

METHODS

The potential performance of this structured approach for the relevant incidents amongst the first 4000 reported to the Australian Incident Monitoring Study (AIMS) was compared with the actual management as reported by the anaesthetists involved.

RESULTS

There were 189 reports of laryngospasm among the first 4000 incidents reported to AIMS. These were extracted and analysed. In 77% of cases laryngospasm was clinically obvious, but 14% presented as airway obstruction, 5% as regurgitation or vomiting, and 4% as desaturation. Most were precipitated by direct airway stimulation (airway manipulation, regurgitation, vomiting, or blood or secretions in the pharynx), but patient movement, surgical stimulus, irritant volatile agents, and failure to deliver the anaesthetic were also precipitating factors. Desaturation occurred in over 60% of cases, bradycardia in 6% (23% in patients aged <1 year), pulmonary oedema in 4%, and pulmonary aspiration in 3%. It was considered that, correctly applied, the combined core algorithm and sub-algorithm recommended for the diagnosis and management of laryngospasm would have led to earlier recognition of the problem and/or better management in 16% of cases.

CONCLUSION

Laryngospasm may present atypically and, if not promptly managed effectively, may lead to morbidity and mortality. Although usually promptly recognised and appropriately managed, the use of a structured approach is recommended. If such an approach had been used in the 189 reported incidents, earlier recognition and/or better management may have occurred in 16% of cases.

Emergence agitation in preschool children: double-blind, randomized, controlled trial comparing sevoflurane and isoflurane anesthesia

BACKGROUND

This randomized, double-blind controlled trial was conducted to determine whether the association of sevoflurane for induction and isoflurane for anesthesia maintenance resulted in a lower incidence of postoperative agitation compared with sevoflurane as single agent.

METHODS

After Institute Ethics Committee's approval and parental written informed consent, 128 unpremedicated children (1-6 years), ASA I-II, scheduled for elective subumbilical surgery were enrolled. After induction with 8% sevoflurane, patients were randomly allocated to receive sevoflurane or isoflurane 1-1.5 MAC as maintenance agent. The primary endpoint of the study was the incidence of postoperative agitation defined as a screaming and crying child and/or a child that required physical restraint during emergence.

RESULTS

Eighteen children were excluded because they received sedatives, analgesia or anesthesia or because of ineffective regional analgesia before randomization. Fifty-four patients receiving sevoflurane and 56 receiving isoflurane completed the study. Twenty-eight children (95% CI 38-66%) in the sevoflurane group presented with postoperative agitation compared with 18 (95% CI 20-46%) patients receiving isoflurane (P = 0.028). Fifteen minutes after awakening, 11/54 children receiving sevoflurane were agitated compared with 4/56 receiving isoflurane (P = 0.03). Thereafter, there was a gradual reduction in the incidence of postoperative agitation over time.

CONCLUSIONS

The association of sevoflurane for induction and isoflurane for maintenance produced significant less postoperative agitation in preschool children receiving regional anesthesia during subumbilical surgery compared with sevoflurane for induction and maintenance.

Negative-pressure pulmonary edema: a rare complication of upper airway obstruction in children

Negative-pressure pulmonary edema is a rare but life-threatening complication of upper airway obstruction. Because negative-pressure pulmonary edema may occur in a large spectrum of pathologies associated with upper airway obstruction, awareness of this condition is crucial during daily clinical practice. We report a case of negative-pressure pulmonary edema during anesthetic recovery to highlight this condition.

CASE

A 2-year-old boy was scheduled for orchidopexy under general anesthesia. Shortly after an uneventful operation, the patient presented airway obstruction. Serious oxygen desaturation and bradycardia ensued, during inefficient attempts at positive-pressure ventilation. After emergency intubation, copious pink secretions emerged from the airway. Pulmonary edema was confirmed by clinical examination, pulse oximetry, and chest radiography. The finding of pulmonary edema was resolved within 24 hours after mechanical ventilation and positive end-expiratory pressure. The child suffered no sequelae. This report highlights the clinical features of negative-pressure pulmonary edema and serves as a reminder to the pediatrician who must be able to recognize and initiate treatment for conditions that are uncommon but life-threatening.

Effects of inhalation anesthetics halothane, sevoflurane, and isoflurane on human cell lines

Cytotoxic and antiproliferative effects of halothane, isoflurane, and sevoflurane in anesthetic doses on human colon carcinoma (Caco-2), larynx carcinoma (HEp-2), pancreatic carcinoma cells (MIA PaCa-2), poorly differentiated cells from lymph node metastasis of colon carcinoma (SW-620), and normal fibroblasts were investigated. Cells were exposed to anesthetic gas mixture consisting of O(2): N2O (35:60 vol.%), halothane (1.5 vol.%) or isoflurane (2.0 vol.%) or sevoflurane (3.0 vol.%), and CO(2) (5 vol.%), for 2, 4, and 6 h. Cytotoxicity of anesthetics was analyzed by validated tetrazolium dye assay MTT test. All anesthetics expressed cytotoxic effects on treated tumor cells in time and cell line dependent manner. Growth suppression in cells exposed to halothane was enhanced in HEp-2 (to 67.7%), Caco-2 (to 76.3%), and SW620 cells (to 80.9%), and was minimal in normal fibroblasts (to 89.4%). Antiproliferative activity of halothane was measured via radioactive precursors incorporation assay. In Caco-2 cells treated by halothane, decrease in DNA synthesis (52.4%, p=0.001), RNA synthesis (39.2%, p<0.001), and protein synthesis (19.2%, p=0.004) was observed. In HEp-2 cells, DNA and RNA syntheses were decreased to 72.5% and 79.9%, whereas protein synthesis was 14.0% of control (p<0.001). In SW620 cells, protein synthesis after 4 h was 24.4% (p=0.007). A DNA fragmentation was observed in Caco-2 and MIA PaCa-2 cells. Exposition of phosphatidylserine on outer lipid bilayer plasma membrane of tumor cell treated by halothane proved apoptosis as mode of cell death.

Considerations for anaesthesia in children with haematological malignancy undergoing short procedures

As a result of increased use of risk-directed treatment regimes, there is a regular requirement for short-lasting but painful procedures to be performed on children to aid in diagnosis or treatment. The aim of any anaesthetic technique is to provide analgesia and amnesia with minimal side-effects and early return to former activity levels. We review the implications of haematological malignancy in children with regard to anaesthesia and the consequences arising from both the disease and ensuing treatment. We outline some of the current anaesthetic techniques in use and review the advantages and disadvantages of each.

General anaesthesia or conscious sedation for painful procedures in childhood cancer: the family's perspective

BACKGROUND

Until recently, midazolam sedation was routinely used in our institution for bone marrow aspirates and lumbar punctures in children with cancer. It has been perceived by many doctors and nurses as being well tolerated by children and their families.

AIM

To compare the efficacy of inhalational general anaesthesia and midazolam sedation for these procedures.

METHODS

A total of 96 children with neoplastic disorders, who received either inhalational general anaesthesia with sevoflurane, nitrous oxide, and oxygen (GA) or sedation with oral or nasal midazolam (SED) as part of their routine preparation for procedures were studied. The experiences of these children were examined during their current procedure and during their first ever procedure. Main outcome measures were the degree of physical restraint used on the child, and the levels of distress and pain experienced by the child during the current procedure and during the first procedure. The family's preference for future procedures was also determined.

RESULTS

During 102 procedures under GA, restraint was needed on four occasions (4%) when the anaesthetic mask was first applied, minimal pain was reported, and children were reported as distressed about 25% of the time. During 80 SED procedures, restraint was required in 94%, firm restraint was required in 66%, the child could not be restrained in 14%, median pain score was 6 (scale 0 (no pain) to 6 (maximum pain)), and 90% of the parents reported distress in their child. Ninety per cent of families wanted GA for future procedures. Many families reported dissatisfaction with the sedation regime and raised concerns about the restraint used on their child.

CONCLUSIONS

This general anaesthetic regime minimised the need for restraint and was associated with low levels of pain and distress. The sedation regime, by contrast, was much less effective. There was a significant disparity between the perceptions of health professionals and those of families with respect to how children coped with painful procedures.

Severity of airway hyperreactivity associated with laryngeal mask airway removal: correlation with volatile anesthetic choice and depth of anesthesia

STUDY OBJECTIVE

To compare the influence of anesthetic depth and choice of volatile anesthetic drug on the incidence and severity of airway hyperreactivity associated with Laryngeal Mask Airway (LMA) removal.

DESIGN

Randomized observer-blinded study.

SETTING

Ambulatory Surgical Center at a University Medical Center.

PATIENTS

123 ASA physical status I and II children undergoing infraumbilical procedures.

INTERVENTIONS

Patients were randomly assigned to one of four treatment groups: Group 1 = anesthetic induction with halothane, maintenance with isoflurane, nitrous oxide (N(2)O), and oxygen (O(2)), LMA removed when child awakened; Group 2 =anesthetic induction and maintenance as in Group 1, LMA removed while child anesthetized with age adjusted 2 minimum alveolar concentration (MAC) end-tidal concentration of isoflurane; Group 3 = anesthetic induction and maintenance with sevoflurane, N(2)O, and O(2), LMA removed when child awakened; Group 4 = anesthetic induction and maintenance as in Group 3, but LMA removed while child anesthetized with age-adjusted 2 MAC end-tidal concentration of sevoflurane.

MEASUREMENTS AND MAIN RESULTS

Severity of airway hyperreactivity was graded as mild, moderate, or severe. A significant difference was not found amongst the four groups with respect to mild and moderate airway hyperreactivity. Severe airway hyperreactivity leading to a critical event [partial or complete laryngospasm with oxygen saturation (SPO(2)) < 85%] was only encountered in Group 1 patients (incidence 13%). Adverse airway events (SPO(2) < 90%, vomiting and bronchospasm) were also significantly higher in Group 1 (p < 0.05). Isoflurane use was independently associated with significantly higher airway hyperreactivity when compared with sevoflurane (p < 0.05).

CONCLUSIONS

Depth of anesthesia during LMA removal does not appear to affect the incidence or severity of airway hyperreactivity when sevoflurane is the maintenance anesthetic. However, awake LMA removal during isoflurane anesthesia results in a higher incidence of adverse airway events and carries the risk of severe airway hyperreactivity.

Invasive procedures carried out in conscious children: contrast between North American and European paediatric oncology centres

AIM

To define practice in managing repeated invasive procedures in selected paediatric oncology centres in North America and Europe, especially the United Kingdom; to define and contrast concerns that shape policy making, and to contrast practice, particularly regarding procedures performed on conscious patients.

METHODS

Postal survey: 118 centres of the Pediatric Oncology Group and the United Kingdom Children's Cancer Study Group received questionnaires.

RESULTS

68 questionnaires (58%) were returned (52 from North America, 12 from Europe). For all procedures, North American centres tended to use less effective techniques than European, especially for bone marrow procedures. Many North American centres reported performing these on conscious patients on at least three quarters (25%) or half (30%) the occasions. In contrast, corresponding figures for the European centres were 6% and 0%.

CONCLUSIONS

Many bone marrow procedures are still carried out in the conscious patient despite the safety and effectiveness of modern anaesthetic and deep sedation techniques. There appears to be a greater reluctance to offer these to patients in North American centres than in European ones. This may reflect a misperception that the risks of adverse effects are high. Several non-pharmacological techniques are used, but they remain uncommon.

The safety and efficacy of sevoflurane anesthesia in infants and children with congenital heart disease

We tested the hypothesis that sevoflurane is a safer and more effective anesthetic than halothane during the induction and maintenance of anesthesia for infants and children with congenital heart disease undergoing cardiac surgery. With a background of fentanyl (5 microg/kg bolus, then 5 microg. kg(-1). h(-1)), the two inhaled anesthetics were directly compared in a randomized, double-blinded, open-label study involving 180 infants and children. Primary outcome variables included severe hypotension, bradycardia, and oxygen desaturation, defined as a 30% decrease in the resting mean arterial blood pressure or heart rate, or a 20% decrease in the resting arterial oxygen saturation, for at least 30 s. There were no differences in the incidence of these variables; however, patients receiving halothane experienced twice as many episodes of severe hypotension as those who received sevoflurane (P = 0.03). These recurrences of hypotension occurred despite an increased incidence of vasopressor use in the halothane-treated patients than in the sevoflurane-treated patients. Multivariate stepwise logistic regression demonstrated that patients less than 1 yr old were at increased risk for hypotension compared with older children (P = 0.0004), and patients with preoperative cyanosis were at increased risk for developing severe desaturation (P = 0.049). Sevoflurane may have hemodynamic advantages over halothane in infants and children with congenital heart disease.

IMPLICATIONS

In infants and children with congenital heart disease, anesthesia with sevoflurane may result in fewer episodes of severe hypotension and less emergent drug use than anesthesia with halothane.

[Sever acute pulmonary edema after peri-anesthetic laryngospasm in a newborn infant]

Severe acute pulmonary oedema following peranaesthetic laryngospasm in a newborn. The authors report a case of severe acute pulmonary oedema secondary to a laryngeal spasm in a 3-week-old neonate, immediately after induction of anaesthesia with halothane. After emergency tracheal intubation, the infant experienced a severe, life-threatening pulmonary oedema requiring prolonged intensive care. Such a secondary time course is unusual. Usually pulmonary oedema has a favourable outcome after oxygen administration and maintenance of positive expiration pressure, except in the neonate.

Early intravenous cannulation in children during inhalational induction of anaesthesia

Intravenous cannulation is obtained in almost all patients scheduled for operative intervention under anaesthesia. In our practice, inhalational induction precedes cannulation in children in order to avoid pain and discomfort, and cannulation is delayed until the child is adequately anaesthetized in fear of precipitating laryngospasm due to painful stimulus of venepuncture in the light stage of anaesthesia. This study was performed on 150 patients between two to eight years of age to determine if there is a difference in the incidence of untoward incidents, if cannulation is performed when children are lightly anaesthetized (Early, Group E), as compared to when they are deeply anaesthetized (Late, Group L). In patients randomized to early cannulation, the results showed that there was a significantly shorter time from induction to venous cannulation, the halothane concentration was lower at the time of cannulation, there was a greater incidence of movement on cannulation and a greater incidence of changes in heart rate, blood pressure, and respiratory rate. There was no significant differences in the incidence of laryngospasm or in the success rate of intravenous cannulation between the two groups. We conclude that venous cannulation can be safely performed during the light stages of anaesthesia.

Intravenous methohexital for brief sedation of pediatric oncology outpatients: physiologic and behavioral responses

OBJECTIVE

In this successor to a preliminary retrospective study, we sought to confirm the apparent safety and efficacy of intravenous methohexital (MHX) for brief, unconscious sedation of pediatric hematology/oncology outpatients undergoing painful, invasive procedures.

METHODS

This prospective study was conducted in a children's hospital-based hematology/oncology clinic. Following published monitoring guidelines for deep pediatric sedation, MHX (1.0 mg/kg) was administered immediately before each procedure, 1% xylocaine was given locally, and additional MHX was titrated to maintain minimal response to pain during the procedure. For each patient, the procedural and physiologic response data reported below were recorded from the onset of sedation through recovery. Behavioral distress responses were measured using a standardized pediatric observational tool (Procedure Behavioral Checklist).

RESULTS

Two hundred and thirty-three procedures were carried out in 76 patients ranging .1 to 19.6 years of age. The mean cumulative MHX dose/procedure was 4.6 +/- 2.9 mg/kg. The mean lengths of time from initiation of sedation until completion of the invasive procedure, attainment of patient arousability, discontinuation of monitoring, and attainment of patient alertness were 8 +/- 5, 19 +/- 8, 19 +/- 9, and 22 +/- 9 minutes, respectively. Relative to presedation values, mean arterial pressure (MAP), heart rate, and respiratory rate showed maximum mean percent changes of -16.6, +17.8, and +13.4, respectively (all clinically insignificant). Complications among procedures were transient and included hiccoughs and myoclonus (each 10%); oropharyngeal secretions (6%); and pain at the injection site, emergence phenomena, and mild stridor (each </=3%). Of two procedures (.9%) affected by transient upper airway obstruction associated with emesis or secretions, only one briefly needed mask ventilation. No procedures required intubation or early termination. In 49 additional procedures assessed for patient distress, observed pain responses were absent to mild in 45 (92%) and moderate in 4.

CONCLUSION

MHX appropriately administered provides sedation which is effective, safe, well tolerated, and of short duration, making MHX attractive for use in pediatric oncology outpatients and other populations with similar sedation needs.

Humidification reduces coughing and breath-holding during inhalation induction with isoflurane in children

PURPOSE

Inhalation induction using isoflurane is associated with airway irritability, coughing, breath-holding and laryngospasm. These complications are more common in children. This study was designed to determine if humidification of isoflurane in oxygen/nitrous oxide would reduce respiratory complications and hypoxic episodes at induction.

METHODS

Fifty-nine unpremedicated children, aged three months to 12 yr, were enrolled in the study and randomised to receive either humidified isoflurane (n = 27, Group A), or non-humidified isoflurane (n = 32, Group B). All inductions of anaesthesia were with isoflurane 4% in 50% oxygen/nitrous oxide. Subjects were observed for the occurrence of breath-holding, coughing, laryngospasm, bronchospasm, secretions, and hiccoughs. The severity of each complication was graded on a scale of 0-3. The need to administer 100% oxygen and/or succinylcholine was also identified.

RESULTS

Coughing (33% vs 53%) was more frequent in Group B (P < 0.05). Coughing severity scores (13 vs 36) and breath-holding severity scores (8 vs 19) were also greater in Group B (P < 0.05). A change in FIO2 was required more frequently in Group B (4% vs 16%). Although there was a high incidence of laryngospasm in both groups (52% vs 59%), no other differences were identified, breath-holding (26% vs 31%), secretions (30% vs 31%), hiccough (11% vs 12.5%) (P > 0.05).

CONCLUSION

Humidification of inspired isoflurane reduces the frequency and severity of coughing, the severity of breath-holding, and the need to increase supplemental inspired oxygen concentration, when isoflurane is used for inhalation induction of anaesthesia in children. Humidification has no effect, however, on the frequency and severity of laryngospasm, or on the frequency of occurrence of arterial oxygen desaturation.

A comparison of sevoflurance to halothane in paediatric surgical patients: results of a multicentre international study

Induction, emergence and recovery characteristics were compared during sevoflurane or halothane anaesthetic in a large (428) multicentre, international study of children undergoing elective inpatient surgical procedures. Two hundred and fourteen children in each group underwent inhalation induction with nitrous oxide/oxygen and sevoflurane or halothane. Incremental doses of either study drug were added until loss of eyelash reflex was achieved. Steady state concentrations of anaesthesia were maintained until the end of surgery when anaesthetic agents were terminated simultaneously. Time variables were recorded for induction, emergence and the first need for analgesia in the recovery room. In addition, in 86 of the children in both groups, venous blood samples were drawn for plasma fluoride levels during and after surgery. There was a trend toward smoother induction (induction of anaesthesia without coughing, breath holding, excitement laryngospasm, bronchospasm, increased secretion, and vomiting) in the sevoflurane group with faster induction (2.1 min vs 2.9 min, P = 0.037) and rapid emergence times (10.3 min vs 13.9 min, P = 0.003). Among the children given sevoflurane, 2% developed bradycardia compared with 11% in the halothane group. Postoperatively, 46% of the children in the halothane group developed nausea and or vomiting versus 31% in the sevoflurane group (P = 0.002). Two children in the halothane group developed cardiac dysrhythmia and were dropped from the study. In addition, a child in the halothane group developed malignant hyperthermia, received dantrolene, and had an uneventful recovery. Mean maximum inorganic fluoride concentration was 18.3 microM.l-1. The fluoride concentrations peaked within one h of termination of sevoflurane anaesthetic and returned rapidly to baseline within 48 h. This study suggests that sevoflurane may be the drug of choice for the anaesthetic management of children.

A comparative study of cognitive behavior therapy versus general anesthesia for painful medical procedures in children

A treatment outcome study was conducted to compare the efficacy of cognitive behavior therapy (CBT) versus general anesthesia in alleviating the distress of 18 pediatric cancer patients (ages: 3-12 years) undergoing bone marrow aspirations (BMAs). CBT and short-acting mask anesthesia were delivered within a repeated-measures counterbalance design. Results indicated that children exhibited more behavioral distress in the CBT condition for the 1st minute lying down on the treatment table. However, parents rated significantly more behavioral adjustment symptoms 24 h following the BMA when their children had received anesthesia. No differences were found in childrens' and parents' preference for CBT versus anesthesia.

Total intravenous anesthesia for children undergoing brief diagnostic or therapeutic procedures

STUDY OBJECTIVE

To compare the quality of anesthesia with propofol, ketamine, or etomidate in children undergoing brief diagnostic or therapeutic procedures.

DESIGN

Retrospective study.

SETTING

University hospital.

PATIENTS

971 pediatric oncology patients undergoing brief diagnostic or therapeutic procedures outside the operating room during a one-year period.

INTERVENTIONS

Total intravenous anesthesia was administered primarily with ketamine, etomidate, or propofol for oncology-related procedures such as bone marrow aspiration, lumbar puncture, radiologic imaging, and radiation therapy. Quality assurance data were collected for all patients, including anesthetic technique, dosage, and the occurrence of specific adverse events during anesthesia and recovery periods.

MEASUREMENTS AND MAIN RESULTS

There were 279 anesthesia-related occurrences, comprised almost entirely of five specific events: vomiting, hypoxemia (SpO2 less than 94%), tachycardia, agitation, and myoclonus. Ketamine was associated with vomiting (14.6%), agitation (15.0%), and tachycardia (19.5%). Etomidate was also associated with vomiting (9.9%) and agitation (1.2%). Hypoxemia was rare except in the propofol group (15.7%) and was easily managed with supplemental oxygen, but occasionally required manually assisted ventilation via face mask. In patients receiving propofol vomiting (0.5%) and agitation (1.2%) were rare.

CONCLUSIONS

Anesthesia with propofol, ketamine, or etomidate is safe and efficacious for children undergoing brief procedures. Propofol is associated with a decreased incidence of postanesthetic agitation and vomiting. Its association with respiratory depression is confirmed.

Anesthesia considerations for pediatric cancer

The multidisciplinary approach to the care of children with cancer demands an understanding of all aspects of its treatment. Recognition of potential anatomic and physiologic derangements which may result from specific types of malignancy allows optimal preoperative preparation. Understanding the anesthetic implications of cancer chemotherapy, irradiation and surgery, and the medical complications which result, is essential. The anesthesiologist is involved in critical perioperative issues during surgical resection in the operating room, but just as importantly plays a crucial role in a variety of procedures performed in remote locations. An awareness of special problems related to cancer and its treatment allows optimal anesthesia care while dealing with such issues as radical surgery, organ system failure, acute and chronic pain, and terminal illness.

Recovery following outpatient anesthesia: use of enflurane versus propofol

STUDY OBJECTIVE

To compare the intraoperative conditions and postoperative recovery of patients following the use of either propofol-nitrous oxide (N2O) or enflurane-N2O for maintenance of outpatient anesthesia.

DESIGN

Randomized, single-blind study.

SETTING

University hospital outpatient surgery center.

PATIENTS

61 ASA physical status I and II, healthy female outpatients undergoing laparoscopic surgery.

INTERVENTIONS

Patients were randomly assigned to one of three anesthetic regimens. Group 1 (control) received thiopental sodium 4 mg/kg intravenously (i.v.), followed by 0.5% to 1.5% enflurane and 67% N2O in oxygen (O2). Group 2 received propofol 2 mg/kg i.v., followed by 0.5% to 1.5% enflurane and 67% N2O in O2. Group 3 received propofol 2 mg/kg i.v., followed by propofol 50 to 160 micrograms/kg/min i.v. and 67% N2O in O2. All patients received succinylcholine 1 mg/kg i.v. to facilitate tracheal intubation and atracurium 10 to 20 mg i.v. to provide adequate relaxation during the maintenance period.

MEASUREMENTS AND MAIN RESULTS

Recovery from anesthesia was assessed by a research nurse who was unaware of the anesthetic technique used. The mean +/- SD time to eye opening was significantly longer in the thiopental-enflurane-N2O group (Group 1) than in the propofol-propofol-N2O group (Group 3) (6.1 +/- 2.5 minutes vs. 3.5 +/- 2.8 minutes, respectively). In addition, the mean time to respond to verbal commands was significantly shorter in the propofol induction groups compared with the thiopental induction group. However, the use of enflurane versus propofol for maintenance of anesthesia did not significantly prolong the time from arrival in the recovery room to sitting, tolerating oral fluids, walking, or being judged "fit for discharge." There were no differences among the three groups with respect to postoperative pain or analgesic requirements. Finally, patients who received enflurane for maintenance of anesthesia had a significantly higher frequency of nausea and vomiting than the propofol maintenance group.

CONCLUSION

Induction of anesthesia with propofol is associated with a more rapid emergence from anesthesia than induction with thiopental. Maintenance of anesthesia with enflurane did not prolong recovery compared with maintenance with propofol, but enflurane was associated with increased frequency of postoperative nausea and vomiting.

Induction, maintenance and recovery characteristics of desflurane in infants and children

To determine the induction and recovery characteristics of the new poly-fluorinated anaesthetic desflurane, 78 fasting and unpremedicated neonates, infants and children up to 12 yr of age were studied. Patients were stratified according to age: full-term neonates less than 28 days of age (n = 12), infants 1-6 mth (n = 12) infants 6-12 mth (n = 15), children 1-3 yr (n = 15), 3-5 yr (n = 12), and 5-12 yr (n = 12). After preoxygenation for two minutes and an awake tracheal intubation, neonates were anaesthetized with stepwise increases in the inspired concentration of desflurane in an air/oxygen mixture. Infants 1-12 mth of age and children were anaesthetized with stepwise increases in the inspired concentration of desflurane in oxygen. Their tracheas were intubated under deep desflurane anaesthesia without muscle relaxation. The incidence of airway reflex responses (including breathholding, coughing, laryngospasm, bronchospasm and oropharyngeal secretions), incidence of excitement, minimum arterial oxygen saturation, and times to loss of eyelash reflex and tracheal intubation during induction were recorded. After skin incision, anaesthesia was maintained with desflurane (approximately 1 MAC) in 60% nitrous oxide and oxygen. Heart rate and systolic arterial pressure were recorded awake, at approximately 1 MAC before and after skin incision and throughout surgery. At the completion of surgery, all anaesthetics were discontinued and the lungs were ventilated with 100% oxygen. During emergence, the end-tidal concentration of desflurane was recorded until extubation. The incidence of airway reflex responses and the times to eye opening and extubation after the discontinuation of desflurane were recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

Cross-sectional study of complications of inhalational anaesthesia in 16,995 patients

Patients undergoing anaesthesia in which halothane, enflurane or isoflurane were used, were surveyed with reference to 16 unwanted effects selected by the nominal group method. A simple record card was completed at the time of anaesthetic administration. The overall incidence of complications was 13.9%. One complication was reported in 10.8% of the cases, and more than one in 3.1%. Complications were more frequent in the obese, the elderly and those patients receiving isoflurane, but in view of the small overall use of this agent, the anaesthetists involved may still have been on a learning curve.

Laryngospasm-induced pulmonary edema

We report the case of a 6-month-old child who developed acute pulmonary edema because of laryngeal spasm during orthopedic manipulations for congenital hip dysplasia. Laryngospasm was probably secondary to an unsuspected light level of anesthesia, maintained via face mask. No other predisposing factors, such as enlarged adenoid tonsils, laryngitis, epiglottitis, mechanical stimulation of the larynx or aspiration of foreign material were identified. Serious oxygen desaturation and bradycardia ensued, during inefficient attempts at positive pressure ventilation. After emergency intubation without muscle relaxant, copious pink secretions emerged from the airway. Negative pressure pulmonary edema was confirmed by chest X-ray, and short-lasting arterial desaturation despite positive pressure ventilation with high oxygen concentration. This type of pulmonary edema is caused by marked elevated negative intra-airway pressure, massive sympathetic discharge causing a blood shift from the systemic to the pulmonary circulation, and accentuation of physiological ventricular interdependence during forceful inspiratory effort against a closed glottis. As usual in such cases, pulmonary edema and laryngospasm resolved spontaneously without specific treatment, and extubation was carried out uneventfully two hours later. The child suffered no sequelae.

Elevated serum bromide concentrations following repeated halothane anaesthesia in a child

A 20-month-old child received 25 brief halothane general anaesthetics over a five-week period to allow cranial irradiation treatments for a posterior fossa ependymoma. Personality change during the last week of the treatment protocol raised the question of possible bromide intoxication. Serum bromide concentrations, using a gold chloride assay technique, were monitored at that time, and at four- and six-week intervals thereafter. Serum bromide concentrations demonstrated a four-fold change during this period ranging from peak levels of 2.2 mEq.L-1 (176 micrograms.kg-1) during the fifth week of treatment decreasing to less than 0.5 mEq.L-1 (less than 40 micrograms.ml-1) six weeks following the end of treatments. This demonstrates the possibility for repetitive, short halothane exposures to result in elevations of serum bromide and the potential of bromide intoxication in paediatric neuro-oncology patients.

Anesthetic considerations in the pediatric cancer patient

Cancer is second only to trauma as the leading cause of death in children 1-15 years of age. Pediatric cancer patients have unique physiologic, pharmacologic, and psychologic considerations that present a unique challenge to plan anesthesiologist. A thorough understanding of pediatric tumors, along with chemotherapeutics and their complications, is necessary to plan anesthetic management properly. Special attention is directed to the psychologic needs and preparation of both the patient and parents. Close cooperation and coordination among the pediatric oncologist, surgeon, and anesthesiologist are necessary for safe and expeditious operative care.

The management of pain associated with pediatric procedures

This article provides guidelines for the psychological and pharmacologic management of pain and anxiety for children undergoing medical procedures. The goals of intervention are presented, as well as issues warranting consideration in planning intervention to reduce procedure-related distress.

Induction reflex actions with intravenous nalbuphine as an adjunct to isoflurane

Ninety unpremedicated patients undergoing mask anaesthesia were assigned to one of three groups according to the volatile anaesthetic and the acute intravenous premedication administered. Group I received saline placebo as premedication and halothane by inhalation. Group II received saline placebo and isoflurane by inhalation. Group III received nalbuphine 0.1 mg.kg-1 IV as premedication and isoflurance by inhalation. Mean time to loss of consciousness (71 sec) did not differ among groups. The dosage of thiopentone required to induce loss of consciousness was decreased by 15 per cent (from 3.9 to 3.3 mg.kg-1) by nalbuphine premedication (P less than 0.05), and time to induction of surgical anaesthesia using isoflurane was decreased by 15 per cent (P less than 0.05). The incidence of reflex actions (coughing, laryngospasm, breath holding, hiccoughs and movement) during induction was no different in the saline-premedicated halothane or isoflurane groups. Acute intravenous nalbuphine premedication decreased significantly the incidence of reflex actions during induction of isoflurane anaesthesia from 77 per cent to 37 per cent (P less than 0.02). Desaturation episodes (SaO2 less than 90 per cent) were more frequent with isoflurane inductions compared with halothane (55 per cent vs 17 per cent, P less than 0.01). Apnoeic episodes accounted for the majority of desaturations associated with nalbuphine premedication, while excitatory reflexes (coughing and laryngospasm) accounted for more desaturations with isoflurane alone.

Anaesthetic induction with isoflurane or halothane. Oxygen saturation during induction with isoflurane or halothane in unpremedicated children

The authors performed a randomised, prospective trial in which one junior anaesthetist administered gaseous induction of anaesthesia to 50 unpremedicated children with either isoflurane or halothane in nitrous oxide and oxygen. Arterial oxygen saturation and the electrocardiogram were monitored and the incidence of complications noted. Desaturation below 85% occurred in six children, but only with isoflurane. The incidences of complications and desaturation events did not alter throughout the 25 isoflurane inductions. Coughing, movement, laryngospasm and sinus tachycardia occurred more frequently with isoflurane. Isoflurane inductions took longer (7.9 as compared with 5.4 minutes, p less than 0.001) and had 4.25 times the number of complications.

The respiratory effects of isoflurane, enflurane and halothane in spontaneously breathing children

The respiratory effects of halothane, isoflurane and enflurane were assessed during nitrous oxide anaesthesia (N2O 50%) in three groups of unstimulated, spontaneously breathing children who weighed 10-20 kg and were aged 1-6 years. Respiratory variables were measured or calculated from capnographic and pneumotachographic recordings at three multiples of minimal alveolar concentration (MAC). The slope of the carbon dioxide response was measured. Similar increases in end tidal carbon dioxide were found for the three agents at each MAC multiple, and similar decreases in tidal volume and in the slope of the ventilatory response to carbon dioxide. A dose-related tachypnoea occurred with halothane and a significant decrease in the duration of inspiration and the duration of each breath at the deepest level of anaesthesia. A significant increase in both these times occurred with enflurane, and a decrease in respiratory rate. No change in respiratory rate occurred with isoflurane at increasing alveolar concentrations whereas at each level of anaesthesia inspiratory time was significantly reduced.

Anaesthesia and monitoring for paediatric radiotherapy

Four hundred and sixty-nine anaesthetics were given to 27 children between the ages of 18 months and 5 years so that they could receive radiotherapy. When ketamine was used as the sole anaesthetic agent, the induction of anaesthesia was frequently stressful and traumatic, with problems and difficulties being encountered during 24% of anaesthetics. A change to an entirely gaseous method of inducing and maintaining anaesthesia resulted in a much more acceptable service being offered to the children and the incidence of complications fell to only 4%. The problems of monitoring children whilst they receive radiotherapy under general anaesthesia are discussed, the merits of different methods are reviewed and the use of the capnograph is commended.