Joan C. Bevan

Preoperative parental anxiety predicts behavioural and emotional responses to induction of anaesthesia in children

Parental presence at induction of anaesthesia is desirable if it makes the child happier and more cooperative. This study evaluated the emotional and behavioural responses of children to being accompanied by a parent at induction of anaesthesia in a paediatric day-care surgical centre. One hundred and thirty-four patients (aged 2–10 yr, ASA physical status I or II) were divided into two groups by day of surgery, to have a parent present at induction of anaesthesia (treatment group), or to be unaccompanied (control group). Before, and at one week after surgery, the child’s fears and behaviour were scored by the Hospital Fears Inventory (HFI) and Behavioural Questionnaire (BQ), and parental anxiety by the Parents’ Questionnaire (PQ) before and at one week after surgery. The Global Mood Scale (GMS) was used to assess the child’s behaviour and the Visual Analogue Scale (VAS) to assess the parent’s anxiety on arrival for surgery and at induction of anaesthesia. All patients and parents were disturbed by the experience, but to the same degree in the treatment and control groups. Subgroups of “ calm ” and “ anxious ” parents were identified by a median split of their preoperative VAS scores. Children in the“ calm-treatment,” “ calm-control ” and“ anxious-control ” subgroups were similarly upset at induction. Children in the“ anxious-treatment ” subgroup were the most disturbed at induction, and significantly more than those in the“ anxious-control” subgroup. Preoperative parental anxiety levels also correlated with the child’s fears and behaviour one week after surgery. Therefore, parental anxiety should be assessed preoperatively to allow“calm” parents to be present at induction if they wish, and“anxious” parents to be excluded and receive counselling and support.RésuméLa présence des parents au moment de I’induction de I’anes-thesie est désirable si elle rend I’enfant plus heureux et plus coopératif. Cette étude a évalué les réponses émotionnelles et le comportement des enfants accompagnés de leurs parents lors de I’induction de I’anesthésie dans un centre de chirurgie périatrique externe. Cent trente-quatre patients âgés de 2–10 ans, ASA I ou II) ont été divisés en deux groupes, le groupe traitement fut accompagné alors que pour le groupe «contrôle», aucun parent n’accompagnait l’enfant. Avant et aprés une semaine de la chirurgie, les craintes de l’enfant et son comportement furent évalués par les tests de « Hospital Fears Inventory » (HFI) et le « Behavioural Questionnaire » (BQ) et l’anxiété des parents fut évaluée par le questionnaire des parents (PQ). Le test du « Global Mood Scale » (GMS) a ete utilise afm d’évaluer le comportement de l’enfant et le test du « Visual Analogue Scale » (VAS) fut utilisé afin d’évaluer l’anxiété des parents à l’arrivée de la chirurgie et à l’induction de l’anesthésie. Tous les patients et les parents étaient perturbés par l’expérience, mais au même degré entre le groupe « traitement » et le groupe « controle ». Des sous-groupes de parents « calmes » et « anxieux » ont ete identifiés. Les enfants des sous-groupes « calmes-traitement » et « calmes-contrôle » et « anxieux-contrôle » etaient perturbés d’une façon similaire lors de l’induction. Les enfants du groupe « anxieux-traitement » etaient les plus perturbés lors de l’induction et significativement plus que le sous-groupe « anxieux-contrôle ». L’état d’anxiété préopératoire des parents était aussi relié aux craintes de l’enfant et à son comportement une semaine après la chirurgie. Ainsi, l’anxiété parentérale doit être évaluée dans la période préopératoire afin de calmer les parents présents à l’induction s’ils le désirent et les parents anxieux doivent être exclus et doivent recevoir support et conseil.

Residual Block after Mivacurium with or without Edrophonium Reversal in Adults and Children

Background The rapid recovery from mivacurium-induced neuromuscular block has encouraged omission of its reversal. The purpose of this study was to determine, in children and in adults, whether failure to reverse mivacurium neuromuscular block was associated with residual neuromuscular block on arrival in the postanesthesia care unit. Methods In 50 children, aged 2-12 yr, and 50 adults, aged 20-60 yr, anesthesia was induced and maintained with propofol and fentanyl, and neuromuscular block was achieved by an infusion of mivacurium, to maintain one or two visible responses to train-of-four (TOF) stimulation of the ulnar nerve. At the end of surgery, mivacurium infusion was stopped, and 10 min later, reversal was attempted with saline or 0.5 mg *symbol* kg sup -1 edrophonium by random allocation. On arrival in the postanesthesia care unit, a blinded observer assessed patients clinically and by stimulation of the ulnar nerve with a Datex electromyogram in the uncalibrated TOF mode. Results Children arrived in the postanesthesia care unit 8.2 +/-3.4 min after reversal of neuromuscular block and showed no sign of weakness, either clinically or by TOF stimulation. Although TOF ratio was greater in children who had received edrophonium (1.00 +/-0.05 vs. 0.93+/-0.01, P < 0.01), TOF was > 0.7 in all children. Adults arrived in the postanesthesia care unit 12.9+/- 5.3 min after reversal of neuromuscular block (P < 0.01 vs. children). Six in the saline group demonstrated weakness (two required immediate reversal of neuromuscular block, and TOF was < 0.7 in four others), compared with TOF < 0.7 in only one of the edrophonium group (P < 0.05). Conclusions This study demonstrated that, in adults, failure to reverse mivacurium neuromuscular block was associated with an increased incidence of residual block. Such weakness was not observed in children receiving similar anesthetic and neuromuscular blocking regimens.

Early and late reversal of rocuronium and vecuronium with neostigmine in adults and children

UNLABELLED We investigated the influence of the timing of neostigmine administration on recovery from rocuronium or vecuronium neuromuscular blockade. Eighty adults and 80 children were randomized to receive 0.45 mg/kg rocuronium or 0.075 mg/kg vecuronium during propofol/fentanyl/N2O anesthesia. Neuromuscular blockade was monitored by train-of-four (TOF) stimulation and adductor pollicis electromyography. Further randomization was made to control (no neostigmine) or reversal with 0.07 mg/kg neostigmine/0.01 mg/kg glycopyrrolate given 5 min after relaxant, or first twitch (T1) recovery of 1%, 10%, or 25%. Another eight adults and eight children received 1.5 mg/kg succinylcholine. At each age, spontaneous recovery of T1 and TOF was similar after rocuronium and vecuronium administration but was more rapid in children (P < 0.05). Spontaneous recovery to TOF0.7 after rocuronium and vecuronium administration in adults was 45.7 +/- 11.5 min and 52.5 +/- 15.6 min; in children, it was 28.8 +/- 7.8 min and 34.6 +/- 9.0 min. Neostigmine accelerated recovery in all reversal groups (P < 0.05) by approximately 40%, but the times from relaxant administration to TOF0.7 were similar and independent of the timing of neostigmine administration. Recovery to T1 90% after succinylcholine was similar in adults (9.4 +/- 5.0 min) and children (8.4 +/- 1.1 min) and was shorter than recovery to TOF0.7 in any reversal group after rocuronium or vecuronium administration. Recovery from rocuronium and vecuronium blockade after neostigmine administration was more rapid in children than in adults. Return of neuromuscular function after reversal was not influenced by the timing of neostigmine administration. These results suggest that reversal of intense rocuronium or vecuronium neuromuscular blockade need not be delayed until return of appreciable neuromuscular function has been demonstrated. IMPLICATIONS These results suggest that reversal of intense rocuronium or vecuronium neuromuscular blockade need not be delayed until return of appreciable neuromuscular function has been demonstrated. Although spontaneous and neostigmine-assisted recovery is more rapid in children than in adults, in neither is return of function as rapid as after succinylcholine administration.

Sickle cell states and the anaesthetist

Characteristics of sickle ceil disease History Epidemiology and genetics Association with malaria Inheritance Clinical features Modifiers of clinical severity Pathophysiology Haemoglobinopathy Oxygen affinity Blood viscosity Cell membrane damage Micrncirculatory changes Molecular biology of sickle eelI anaemia Diagnosis Clinical examination Peripheral blood film and CBC Haemoglobin e]ectrophoresis I~rnergeney use of sodium metabisulphate preparation Neonatal diagnosis Prenatal diagnosis Treatment Supportive Specific therapies Augmentation of haemoglobin F Bone marrow transplantation Transfusion therapy Organization of Sickle Cell Centres in North America Management of general anaesthesia Preoperative considerations Technique of anaesthesia Sielde ceil crisis intraoperatively Controversies in anaesthetic management Preoperative use of blood transfusions The obstetric patient Neonates and infants The patient for open heart surgery

Onset of maximum neuromuscular block following succinylcholine or vecuronium in four age groups

Background:Increasing age appears to be associated with a slower onset of neuromuscular blockade, but such an effect has not been studied with the same doses of the same drugs across pediatric and adult age groups. Methods:The authors measured the evoked compound action potential of the adductor pollicis muscle in response to 0.1-Hz stimulation of the ulnar nerve, during fentanyl-thiopental-oxygen anesthesia, in 160 patients aged 1–3 yr, 3–10 yr, 20–40 yr, or 60–80 yr. Subparalyzlng doses of vecuronium (0.03 mg/kg) or succinylcholine (0.3 mg/kg), or paralyzing doses of vecuronium (0.1 mg/kg) or succinylcholine (1.0 mg/kg), were administered to ten patients in each age group. Results:Onset time, defined as the time from injection to maximum depression of response with a subparalyzlng dose or the time from injection to ablation of visible response with a paralyzing dose, varied with age in all groups (P < 0.001). For 0.3 mg/kg succinylcholine, it increased from 49 ± 6 s in 1–3-yr-old patients, to 104 ± 9 s in 60–80-yr-old patients (P < 0.00001). For 0.03 mg/kg vecuronium, onset time was 3.6–5.9 times longer than for succinylcholine, increasing from 219 ± 15 s in 3–10-yr-old patients to 473 ± 30 s in 60–80-yr-old patients (P < 0.00001 by linear regression). For paralyzing doses, succinylcholine 1.0 mg/kg had an onset time of 58 ± 7 s and 95 ± 7 s, in 1–3-yr-old and 60–80-yr-old patients, respectively (P < 0.001). For 0.1 mg/kg vecuronium, onset time varied between 125 ± 19 s in 1–3-yr-old patients to 295 + 31 s in 60–80-yr-old patients (P < 0.00001), and was 2.1–3.3 times longer than 1 mg/kg succinylcholine. Conclusions:Increasing age is associated with slower onset for both succinylcholine and vecuronium. When equipotent, subparalyzing doses of succinylcholine and vecuronium are compared, onset time is 4.5 times as long with vecuronium.

Midazolam premedication delays recovery after propofol without modifying involuntary movements

Midazolam has GABAergic effects in children that may modify propofol-induced involuntary movements, yet delay recovery. In a double-blind, randomized study, 24 children (2-7 yr of age, ASA physical status I or II) undergoing short surgical procedures received midazolam 0.5 mg/kg (Group M) or placebo (Group P) per os 20-30 min before propofol anesthesia (5 mg/kg intravenously followed by an infusion). Blind observers scored sedation and anxiety levels (scale 1-4) before premedication, at separation from parents, and at induction of anesthesia. Induction and emergence were videotaped, and body movements were recorded. During recovery, times to eye opening and maximum Steward (SS = 6) and Vancouver Sedative Recovery (VSRS = 22) scores were noted. Parents were questioned about side effects that may have occurred during the following week. Both groups were similar in age, sex, weight, timing of premedication, propofol dose, and duration of surgery. The incidence of involuntary movements did not differ between groups but was higher at induction (79%) than on emergence (25%) (P < 0.05). Anxiety and sedation scores were similar in Group P and Group M, but recovery took longer after midazolam, with eye opening (mean +/- SD) 24 +/- 7 vs 43 +/- 18 min, maximum SS (median and range) 27 (13-37) vs 55 (24-138) min, and maximum VSRS 51 (30-100) vs 80 (50-130) min. Children returned to normal activity in 1 (0-5) day, and none exhibited neurological complications. We conclude that an oral premedicant dose of midazolam prolongs recovery from anesthesia in children without affecting dystonic movements after propofol. (Anesth Analg 1997;85:50-4)

Dose-related effects of succinylcholine on the adductor pollicis and masséter muscles in children.

This study was performed to détérmine the effects of various doses of succinylcholine on resting tension and evoked twitch height at the masséter and adductor pollicis muscles in children. Twenty patients, aged 3–10yr, ASA physical status I or II, were randomly assigned to receive succinylcholine 0.15, 0.25, 0.50 or 1.00 mg · kg−1, during halothane-nitrous oxide anaesthesia. Supramaximal train-of-four stimulation was applied simultaneously to the ulnar nerve and the nerve to the masséter. Transducers recorded force at the jaw and the thumb. Maximum blockade of the first twitch (T1) and maximum resting tension change were measured. Potency of succinylcholine at the two muscles was estimated by linear regression of the logit transformation of T1 versus log dose. The relationship between resting tension change and log dose was established by linear regression. The masséter muscle was more sensitive to succinylcholine than the adductor pollicis with an ED95 of 0.28 ± 0.02 (mean ±SEM) vs 0.44 ± 0.05 mg · kg−1 (P < 0.05). Onset of neuromuscular blockade was faster at the masséter, and recovery occurred simultaneously in both muscles. A dose-related increase in resting tension was observed in both muscles, but its magnitude was five times greater at the masséter. With succinylcholine, 1 mg · kg−1, this increase was 51.6 ± 16.8 g at the masséter and 9.1 ± 2.3 g at the adductor pollicis. Tension returned to baseline within 1–2 min. It is concluded that in children (1) succinylcholine produces dose-related changes in resting tension; (2) this effect, although quantitatively important at the masséter, is not restricted to that muscle; and (3) relatively small doses of succinylcholine are required to block neuromuscular transmission at the jaw.RésuméCette etude fut congue afin de d’étérminer les effets de différentes doses de succinylcholine sur la tension de repos et la hauteur du twitch évoqué pour le muscle du mass’étér et l’adducteur du pouce chez les enfants. Vingt patients ages de 3–10 ans, état physique ASA I ou II, ont été randomises afin de recevoir la succinylcholine 0,15, 0,25, 0,50 ou 1.00 mg · kg−1, lors d’une anesthésie l’halothane-protoxyde d’azote. Une stimulation d’une ondée-de-quatre (TOF) a été appliquee simultanément au nerf cubital et au nerf du masséter. Des transduceurs ont enregistré des forces au niveau de la mâchoire et du pouce. Le blocage maximal du premier twitch (T1) et les changements de la tension de repos maximal ont été mesurés. Le muscle masséter était plus sensible a la succinylcholine que l’adducteur du pouce avec un ED95 de 0,28 ± 0,02 (moyenne ± SEM) vs0,44 ± 0,05 mg · kg−1 (P < 0.05). Le débit du blocage neuromusculaire était plus rapide pour le masséter et la recuperation est survenue simultanément dans les deux muscles. Une augmentation dépendamment de la dose dans la tension de repos a été observée dans les deux muscles et son amplitude était cinq fois plus élevée au niveau du masséter. Avec du succinylcholine, 1 mg · kg−1 cette augmentation était de 51,6 ± 16,8 g au masséter et 9,1 ± t2,3 gà l’adducteur du pouce. Cette augmentation de la tension diminua au niveau contrôle a l’interieur de 1–2 min. On conclut que chez les enfants 1) la succinylcholine produit des changements dépendants de la dose dans la tension de repos; 2) cet effet, quoique quantativement supérieur au niveau du masséter, n’est pas limité à ce muscle; et 3) relativement des petites doses de succinylcholine sont nécessaires afin d’acquérir un blocage neuromusculaire au niveau de la mâchoire.

Parental Presence During Anesthesia Induction

n the past few decades, numerous studies demonstrating the negative psychosocial effect I of hospitalization on children have been published. These effects appear to be worse when invasive procedures are involved.’ Nurses have been concerned with decreasing the distress experienced by children preparing for surgery? One source of children’s stress is separation from parents, even though there are some questions about the effects of parental presence during invasive and stressful procedures. For example, during immunization, children actually cry more in the presence of their parents.3 This was interpreted as positive behavior because the children felt free to express their distress. The researchers presumed that the children suffered shorter-lasting effects; however, this was not followed up.

POSTOPERATIVE NEUROMUSCULAR FUNCTION IN PEDIATRIC DAY-CARE PATIENTS

After anesthesia employing nondepolarizing muscle relax‐ants, 30%–40% of adult patients demonstrate residual paralysis with a train‐of‐four ratio <70%, but it is not known if the same is true for children. This study was designed to investigate neuromuscular transmission in 91 ASA physical status I or II day‐care children (aged 0–10 yr) after halothane anesthesia in which pancuronium (n = 34), atracurium (n = 32), or vecuronium (n = 25) was administered. Peripheral nerve stimulation was used clinically to assess neuromuscular blockade during surgery. In the recovery room, the evoked response of the adductor pollicis muscle was measured by train‐of‐four stimulation of the ulnar nerve. This measurement was made (mean ± SEM) at 28.0 ± 1.5, 15.0 ± 1.3, and 15.0 ± 1.7 min after pharmacologic antagonism with 0.02 mg/kg atropine and 0.06 mg/kg neostigmine in the pancuronium, atracurium, and vecuronium groups, respectively. There were no differences in the ages of the patients in the three groups at 4.3 ± 0.4, 4.0 ± 0.4, and 5.0 2 ± 0.5 yr, with 17 children less than 2 yr. Recovery from neuromuscular blockade in all three groups was almost complete. The train‐of‐four ratio (height of fourth twitch compared with the first) was similar in patients who had received pancuronium (96.7% ± 0.9%), atracurium (95.5% ± 0.9%), or vecuronium (96.3% ± 1.3%). Therefore, postoperative muscle weakness or respiratory impairment is unlikely in pediatric day‐care surgical patients more than 2 yr old when these anesthetic techniques are used.

The potency of pancuronium at the adductor pollicis and diaphragm in infants and children

To measure the potency of pancuronium at the diaphragm and adductor pollicis in infants and children, train-of-four stimulation was applied to the ulnar and phrenic nerves under N2O-halothane anesthesia. The force of contraction of the adductor pollicis was measured and compared with the diaphragmatic electromyogram (EMG). Cumulative dose response curves were determined for pancuronium in 18 patients divided equally into three age groups: 0–1 yr, 1–3 yr, and 3–10 yr. The potency of pancuronium at both muscles decreased with increasing age (P < 0.05), while the adductor pollicis:diaphragm potency ratio remained constant. The mean doses (±SEM) required to depress adductor pollicis first twitch responses by 90% (ED90) were 42 ± 3.3 μg/kg in the 0–1-yr group, 47 ± 4.2 μg/kg in the 1–3-yr group, and 62 ± 4.1 μg/kg in the 3–10-yr group. Corresponding figures for the diaphragm were 70 ± 4.3 μg/kg, 81 ± 5.1 μg/kg, and 101 ± 4.4 μg/kg respectively. The ED90 ratios (diaphragm ED90/adductor pollicis ED90) in the three age groups were 1.69 ± .07, 1.75 ± .14, and 1.64 ± .09, respectively. These results are consistent with similar rates of maturation of the diaphragm and the adductor pollicis muscles in infancy and childhood. Thus, train-of-four monitoring of the adductor pollicis is likely to overestimate the degree of neuromuscular blockade of the diaphragm in pediatric patients.