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Clinical Anaesthesia File Anaesthetic management of an asthmatic child for appendicectomy

Case presented by A 13-yr-old boy was scheduled for emergency appendicectomy Brian Kuwahara MD FRCPC because of abdominal pain. HIS preoperative medical history Department of Anaesthesia, was complicated by a recent hospital admission for management Alberta Children's Hospital at the University of Calgary, of . He had presented to hospital seven days earlier be- Calgary, Alberta. cause of dyspnoea, tachypnoea and oxygen desaturation to 77% on room air Following admission, he required intensive non- ventilatory management of his asthma, including intravenous Case discussed by , methylprednisolone, and aminophylline, as well as Gerald V. Goresky MDCM FRCPC use of an ipratroprium bromide inhaler and 100% oxygen by Department of Anaesthesia, mask. He was discharged to the ward, and continued on pred- Alberta Children's Hospital at the University of Calgary, nisone (deltacortisone), beclomethasone inhaler, ipratroprium Calgary, Alberta. inhaler, and salbutamol inhaler During his ICU stay, he com- plained of nonspecific abdominal pain, interpreted as gastro- oesophageal reflux. After four days, he was discharged to the ward. On his sixth hospital day, he began to experience right- sided lower abdominal pain and right shoulder pain. A surgeon was consulted, and the patient was found to have a very tender right lower quadrant with guarding and rebound pain. He was therefore scheduled for appendicectomy; antibiotic therapy with ampicillin, gentamicin, and metronidazole was initi- ated.

Un enfant de 13 ans souffrant de douleurs abdominales est programm~ pour une appendicectomie d'urgence. Son histoire r~vble qu'il ~ dtd hospitalisd peu de temps auparavant pour une crise d'asthme. En effet, sept jours plus t6t, il est admis fi 17~6pital avec de la dyspnde, de la tachypnke et une d~sa- turation en oxygbne de 77% h l'air ambiant. Aprbs son ad- mission, il est trait~ aux soins intensifs, sans ventilation mdca- nique, mais par l'administration intraveineuse de salbutamol, de mdthylprednisolone et d'aminophylline, l'inhalation de bro- Key words mure d'ipratroprium et de l'oxyg~ne ~ 100% au masque. Aprbs COMPLICATIONS: asthma. son retour au service, il continue son traitement avec de la Address correspondence to: Dr. G.V. Goresky, Department prednisone (deltacortisone), et des inhalations de b~clo- of Anaesthesia, Alberta Children's Hospital, 1820 Richmond mdthasone, d'ipratroprium et de salbutamol. Pendant son Road, SW, Calgary, Alberta, Canada T2T 5C7. s~jour aux soins intensifs, il s~tait plaint d'une douleur ab- Acceptedfor publication 24th February, 1994. dominale haute non sp~cifique attribude ,) un reflux gastro-

CAN J ANAESTH 1994 / 41: 6 / pp 523-6 524 CANADIAN JOURNAL OF ANAESTHESIA oesophagien. Quatre jours plus tard, il est ramen~ au service. sion and had been receiving high-dose steroids for seven Le sixibme jour de son hospitalisation, il dit ressentir une dou- days. Consideration must be given to administering a pro- leur abdominale basse du cotd droit et une douleur it l~paule phylactic steroid bolus preoperatively. droite. Un chirurgien consult~ constate que le patient pr~sente Before scheduling surgery, the patient was being fol- une sensibilit~ douloureuse du quadrant infdrieur droit avec lowed by a pulmonary consultant, who recommended an d~fense et une douleur it la d~compression lots de la palpation additional dose of beclomethasone, ipratroprium, and sal- abdominale. I1 est alors programmd pour une appendicectomie butamol. Methylprednisolone 30 mg/v was administered. et on commence un traitement it l'ampicilline, la gentamycine et le m~tronidazole. Physical examination immediately preoperatively revealed an obviously uncomfortable patient. His temperature was 36.2~ pulse rate 97 bpm, respirations 36" rain -a, and Past medical history included five previous admissions weight 60 kg. He was complaining of right shoulder pain to hospital for treatment of acute asthma. He had no and abdominal pain. On chest examination, rhonchi were previous surgery, and his only allergies were to dogs and heard on the right side with forced expiration. On ex- horses. His usual medications at home were salbutamol amination of the abdomen, the patient was exquisitely and beclomethasone inhalers. tender on the right side. The patient stated that his asthma had improved since admission but that he was not yet back to his "usual" state. This patient has several factors complicating the man- Chest x-ray demonstrated perihilar bronchial wall agement of his abdominal pain. First, he is suffering from thickening only: white blood count was 14.2 a recent exacerbation of his asthma. Second, he has ab- cells. 10 9. L -1. Recent pulmonary function tests and dominal pain associated with right shoulder pain. Third, blood gases were not done, but peak expiratory flows he has been chronically using inhaled steroids for man- and oxygen saturation on room air were both within agement of his asthma and recently has been receiving normal limits on discharge from ICU. large doses of methylprednisolone, followed by prednisone for seven days. The administration of general endotracheal anaesthesia At this point, there are a limited number of options re- to a patient who has had a recent acute asthmatic attack garding anaesthetic management. It is evident that the is associated with potential precipitation of broncho- patient is in the best possible medical condition, from spasm, difficult ventilation, hypoxia, and pneumothorax. the pulmonary point of view, that can be expected. Re- In this emergency situation, it is extremely important to gardless, the risks of general anaesthesia are high because assure that the patient's present therapy he would require tracheal intubation following a rapid- has been optimized, and that he receives appropriate sequence induction. Although he has recently recovered preoperative treatment. Preoperative consultation by a from acute asthma, his airway reactivity is expected to pulmonary physician would be appropriate. be substantial, and he is at considerable risk of developing Abdominal pain with associated shoulder pain is an intraoperative and postoperative pulmonary complica- ominous sign, as it frequently indicates diaphragmatic ir- tions. The risks of regional anaesthesia may be less. ritation. In this instance, it may portend the diagnosis If general anaesthesia is the chosen option, careful of peritonitis. The likelihood of peritonitis in the presence monitoring of ECG, blood pressure, oxygen saturation, of appendicitis is higher in this instance because adrenal end-tidal CO2, neuromuscular blockade, breath sounds, steroid therapy diminishes the symptoms produced by in- and ventilatory pressure is important. Agents which are flammation. Any acute may arise, with ei- sympathomimetic or which enhance bronchodilatation ther localized or generalized peritonitis, without the usual are indicated. A well-sedated and deeply anaesthetized symptoms and signs of such inflammation being suffi- patient should experience less coughing, airway irritation, ciently clear to cause alarm. ~ Peritonitis may complicate and bronchospasm. Preanaesthetic sedation with midaz- the management of asthma because of the possibility of olam/v and/or fentanyl should be considered. Following dehydration - if this patient is dehydrated, airway se- preoxygenation and lidocaine 1 mg. kg-I,/v a rapid se- cretions become thick and iuspissated, increasing small quence induction with ketamine and succinylcholine airway closure. would be effective. Maintenance agents which would be The use of systemic steroids is also associated with effective would be halothane or isoflurane (for broncho- adrenal suppression and the inability to mount a phys- dilatation and deep anaesthesia), fentanyl and nitrous iological response to the stress of surgery. In this instance, oxide for analgesia, and pancuronium for muscle relax- the patient was on inhaled beclomethasone before admis- ation. Kuwahara and Goresky: ASTHMA AND APPENDECTOMY 525

Regional anaesthesia is a reasonable option for intraop- Discussion erative anaesthetic management of this individual - either Asthma is a syndrome characterized by increased respon- spinal anaesthesia or epidural anaesthesia. Regardless of siveness of the tracheobronchial tree to a variety of stim- the modality used, the patient would require verbal sup- uli. Patients with asthma have an exaggerated response port, sedation, and careful monitoring of pulse, blood to physical, chemical, and pharmacological stimuli. This pressure, temperature, oxygen saturation, and ventilation. exaggerated response to stimuli is found in 100% of pa- Spinal anaesthesia is less controllable in the level of tients with symptomatic asthma, the situation described blockade obtained, and has a limited duration of anaes- in this patient with appendicitis. thesia unless a continuous spinal catheter is used. Epid- The primary stimulus to precipitate intraoperative ural anaesthesia level is more controllable, block intensity bronchospasm is irritation by an endotracheal tube. should be adequate using lidocaine 1.5%, and duration Therefore, if intubation is required, precautions must be may be unlimited if a continuous catheter is used. One taken to anticipate the irritation by administering agents potential disadvantage to the use of a continuous catheter which block the reflex bronchospasm. Lidocaine given is the possibility of providing a focus for , should prior to intubation in a dose of 1-2 mg. kg -I /v may the patient experience septicaemia. For this reason, con- prevent reflex bronchoconstriction associated with instru- tinuous postoperative epidural analgesia would not be mentation of the airway. Aerosol administration a may recommended. provide no advantage over the intravenous route 3 and Regardless of the anaesthetic technique chosen, man- may even provoke bronchoconstriction. Ketamine has agement of postoperative pain would be most effective been shown to inhibit vagal pathways, to provide direct using intravenous fentanyl (or morphine, if tolerated by relaxation of the airway smooth muscles and to increase this patien0 by continuous infusion or by Patient Con- endogenous plasma catecholamine concentrations which trolled Analgesia. relax the airway via/32-adrenoceptors on airway smooth muscle. 4 Although both isoflurane and halothane are ac- ceptable alternatives as for maintenance Actual course of anaesthesia, halothane at low concentrations has been shown to be a much better bronchodilator than isoflu- After discussing the risks and benefits of anaesthetic al- rane. 5 Because there are fewer airway problems with hal- ternatives with the parents, child, and surgeon, it was othane 6 and because it is a better bronchodilator, hal- agreed that an epidural anaesthetic would be used, pro- othane is more commonly used for paediatric patients vided that the patient was sedated and comfortable. Fol- w~.th asthma. Many neuromuscular agents are capable lowing sedation with midazolam 5.5 mg /v in divided of inducing histamine release from mast cells, and they doses, and application of appropriate monitors, an epi- can potentially increase airway tone - those agents are dural catheter was inserted at the TI2-L 1 level. Lidocaine therefore best avoided in asthmatics. Pancuronium, likely 1.5% in divided doses up to 18 mi was then administered. because of its sympathomirnetic properties, is associated When sensory block of T7 to Lz was attained and meas- with less airway resistance than d-tubocurarine in subjects ured using a nerve stimulator, the surgery began. The with pre-existing lung disease, and is the muscle relaxant patient was found to have peritoneal soiling - the retro- of choice in patients with asthma. Because asthmatics caecal appendix was ruptured. During the procedure, react with bronchoconstriction to very low concentrations gentle peritoneal lavage was required, and some discom- of histamine, narcotics that do not have histamine- fort was experienced by the patient, described as pressure releasing properties might be preferable, but the pref- on his abdomen. An additional 13 ml iidocaine 1.5%, erence of morphine over fentanyl is controversial. Gen- fentanyl 15 ~g, and cyclizine 20 mg iv (for nausea) were erally, in managing asthmatic patients with endotracheal given. The patient was talking intermittently throughout anaesthesia the anaesthetic plan must include choices of the procedure, and was transferred to the recovery room agents that will specifically reduce airway reactivity. one hour and 30 rain after initiation of the epidural an- Although the chronic use of systemic steroid therapy aesthetic. He was given an additional epidural bolus of is associated with adrenal insufficiency, this is not the fentanyl 40 ~g and bupivacaine 0.125%, 10 nd before case with the use of inh~ed steroids for asthma.7 For removal of the epidural catheter in the recovery room. that reason, perioperative steroid supplementation for Postoperatively, his oxygen saturation was 87% breathing stress is not required for asthmatics receiving inhaled bec- room air, and he complained of some difficulty in breath- lomethasone only. In this instance, the use of methyl- ing. He improved with the administration of salbutamoi prednisolone was principally for its antiinflammato(y ef- inhalation and oxygen by nasal prongs. A continuous fects in anticipation of intraoperative or postoperatave morphine infusion was started six hours postoperatively. bronchospasm. 526 CANADIAN JOURNAL OF ANAESTHESIA

Regional anaesthesia is frequently used in paediatric anaesthesia practise, but usually patients are asleep while needles are inserted. Adolescents, however, are acceptable candidates for regional anaesthesia without general anaes- thesia in specific circumstances. In all situations where there is high risk of complications associated with the administration of a general anaesthetic, a regional an- aesthetic technique should be considered.

References 1 Cope, Z. The Early Diagnosis of the Acute Abdomen. 14th ed. London: Oxford University Press, 1972. 2 Downes H, Hirshman CA. Lidocaine aerosols do not pre- vent allergic bronchoconstriction. Anesth Analg 1981; 60: 28-32. 3 Downes 1t, Gerber N, Hirshman CA. I.V. iignocaine in re- flex and allergic bronchoconstriction. Br J Anacsth 1980; 52: 873-8. 4 Hirshman CA, Bergman NA. Factors influencing intrapul- monary airway calibre during anaesthesia. Br J Anacsth 1990; 65: 30-42. 5 Brown RH, Zerhouni EA, Hirshman CA. Comparison of low concentrations of halothane and isoflurane as bron- chodilators. Anesthesiology 1993; 78: 1097-101. 6 Kingston HGG. Halothane and isoflurane anesthesia in pediatric outpatients. Ancsth Analg 1986; 65: 181-4. 7 Barnes PJ, Pedersen S. Efficacy and safety of inhaled stc- rnids in asthma. Am Rev Rcspir Dis 1993; 148: SI-26.