Anaesthetic management of an asthmatic child for appendicectomy

A 13-yr-old boy was scheduled for emergency appendicectomy because of abdominal pain. His preoperative medical history was complicated by a recent hospital admission for management of asthma. He had presented to hospital seven days earlier because of dyspnoea, tachypnoea and oxygen desaturation to 77% on room air. Following admission, he required intensive non-ventilatory management of his asthma, including intravenous salbutamol, methylprednisolone, and aminophylline, as well as use of an ipratroprium bromide inhaler and 100% oxygen by mask. He was discharged to the ward, and continued on prednisone (deltacortisone), beclomethasone inhaler, ipratroprium inhaler, and salbutamol inhaler. During his ICU stay, he complained 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 initiated.     

Anaesthetic management of a patient with a descending thoracic aortic aneurysm and severe bilateral bullous pulmonary parenchymal disease

The anaesthetic management of the surgical repair of a descending aortic aneurysm in a patient with large, bilateral, pulmonary bullae is described. Anaesthesia for descending aortic surgery normally involves unilateral, positive-pressure ventilation, an option which poses some risk of barotrauma in the presence of bilateral bullae. Patients with bullous disease commonly have severe lung disease and thorough preoperative assessment and preparation are necessary. Intraoperatively, bilateral rupture of the bullae could be catastrophic and preparations should be made for this possibility. In order to diminish this risk, a surgical technique including preemptive collapse of the bulla by minithoracotomy and tube drainage, with use of a bronchial blocker to the affected part of the lung may be used. If rupture occurs, then high frequency jet ventilation may be effective. Use of a double lumen endobronchial tube may be advantageous for patients with either unilateral and bilateral bullae. Anaesthesia for patients with bullae should avoid positive-pressure ventilation and nitrous oxide in order to limit the risk of barotrauma from a ball valve mechanism. In this case, the risk of barotrauma was reduced by performing an inhalational induction of anaesthesia and limiting peak inflation pressures during thoracotomy. It was elected to use positivepressure ventilation through a double lumen endobronchial tube following chest incision. A high frequency jet ventilator was available but not employed. Anaesthetic management was complicated by the presence of pleural adhesions, surgical approach directly through a bulla, and the requirement for one lung ventilation. The de i’aone descendante aecouverte cnez un pattent porde grosses bulles bilatérales d’emphysème est discutée, esthésie habituelle pour une chirurgie de l’aorte descendante site une ventilation mécanique unilatérale et constitue ainsi sque additionnel pour le porteur de bulles emphysémas bilatérales. Ces patients ont ordinairement des affections onaires graves et l’évaluation et la préparation préopéraprennent une importance spéciale. Pendant l’intervention, pture de bulles bilatérales peut être catastrophique et il se préparer à cette éventualité. Pour minimiser ce risque, technique chirurgicale qui inclut le collapsus préventif de lle par minithoracotomie et drainage, avec installation d’un ieur bronchique sur la partie atteinte du poumon. Si une re survient, le passage à la ventilation par jet à haute tence peut être salutaire. Le tube endobronchique à double ère peut présenter des avantages aussi bien dans les cas ulles unilatérales que bilatérales. Chez ces patients, il vaut x s’abstenir de ventiler avec une pression positive et du xyde d’azote afin de limiter le risque de barotraumisme soupape. Dans ce cas-ci, on a réussi à limiter le risque arotraumatisme en réalisant une induction par inhalation réduisant la pression d’inflation de pointe pendant la cotomie. Après l’incision thoracique, on a choisi d’utiliser tilation mécanique avec un tube endobronchique à double ère. Un ventilateur à jet à haute fréquence était prêt mais as été utilisé. La gestion de l’anesthésie a été compliquée par dhérences pleurales, par la rencontre d’une bulle d’emphysà l’incision et par l’obligation de ventiler un seul poumon.     

Anaesthetic management of phaeochromo-cytoma associated with tricuspid atresia

The anaesthetic management of a patient with phaeochromocytoma, tricuspid atresia and pulmonary vascular stenosis is reported. The patient received no preoperative preparation with adrenergic blockers. Anaesthesia was induced and maintained with fentanyl, diazepam and sevoflurane. Intraoperative blood pressure was controlled with sodium nitroprusside, sevoflurane, phentolamine, and propranolol. For hypotension after resection of the tumour norepinephrine was required. This patient did not have a systemic to pulmonary shunt procedure performed, so the maintenance of pulmonary blood flow in the presence of haemodynamic instability during operation for phaeochromocytoma was a major concern. Monitoring of oxyhaemoglobin saturation (SpO2) with a pulse oximeter was considered to be useful because SpO2 may reflect pulmonary flow. During serious haemodynamic disturbances due to the manipulation of the tumour, the heart rate was inversely correlated with SpO2, but the relationship between mean arterial pressure and SpO2 was weak. Therefore, control of heart rate appeared to be more important than control of blood pressure in this case.     

Anaesthetic management of a complex morbidly obese parturient

A case is presented of a morbidly obese parturient who had multiple medical problems. She had angina and was receiving nitrate therapy, had insulin-dependent diabetes mellitus, hypertension, asthma and benign intracranial hypertension (pseudotumour cerebri). Lumbar epidural analgesia was chosen for labour and delivery and resulted in an uneventful outcome.     

The Anaesthetic Services Programme Encompassing Nova Scotia (ASPENS)

A comprehensive peer review programme for anaesthesia departments in Nova Scotia was implemented in 1987 by the anaesthesia community. Departments are reviewed by peers at the request of the Head, Department of Anaesthesia, and the President of the Medical Staff. A confidential report with recommendations is written. Twenty-six reviews have been completed (to June 1993) and have most often documented deficiencies in: design of the anaesthesia record, anaesthesia staff recruitment, inadequate documentation of policies for anaesthesia and post-anaesthesia care, peer review/quality assurance processes, organizational structure of hospital medical staffs and operating room committees, and use of anaesthesia equipment that does not meet current (at date of review) CSA standards. In the four hospitals that have been reviewed twice, 24 of the 30 deficiencies noted on the first review had been corrected before the second review which occurred three to five years later. Nine new deficiencies were noted. Departments are encouraged to request a review every four or five years.     

Anaesthetic implications for bone marrow transplant recipients

The bone marrow transplant recipient is unique. Multiple sequelae may arise as a result of the procedure and many of these effects may be pertinent to the planning and administration of anaesthesia. The results indicate that knowledge of these idiosyncrasies accompanied by careful and directed evaluation of each patient should permit the delivery of safe anaesthesia.     

Anaesthetic experience with paediatric interventional cardiology

Anaesthetic and sedation techniques, complications and outcomes were reviewed in 176 children undergoing 184 interventional cardiologic procedures. Techniques included sedation only, and ketamine, inhalational or narcotic anaesthesia. Ketamine infusion was the technique most frequently used. Ketamine was associated with a higher incidence of respiratory complications (P < 0.05) than the other techniques. The higher incidence of hypercarbia (15.6 per cent), which did not affect outcome, may be attributable to the use of supplemental sedatives. The incidence of upper airway obstruction (7.8 per cent) was similar to that of previous studies. Vascular compromise resulted from the procedure in 33 patients, necessitating surgical correction in 16. Cardiac perforation occurred in four cases, causing one death. Pulmonary valve stenosis was most amenable to balloon dilatation and aortic valve stenosis least amenable. Ketamine was the anaesthetic agent preferred by cardiologists for use in the catheterisation suite when general anaesthesia was required. Vigilant monitoring by anaesthetic staff is necessary during the procedure, and avoidance of concomitant narcotics is recommended if a ketamine technique with spontaneous ventilation is used. Les techniques anesthésiques et de sédation ainsi que les complications et les issues ont été revues chez 176 enfants subissant 184 procedures cardiaques. Les techniques ont inctu soil la sédation seulement, soit l’anesthésie à la kétamine, aux agents d’inhalation ou aux narcotiques. La perfusion de kétamine était la technique la plus fréquemment utilisée. La ketamine était associée à une plus grande incidence de complication respiratoire (P < 0.05) comparativement aux autres techniques. La plus grande incidence d’hypercarbie (15.6 pour cent), n’ayant pas affecté l’issue, pourrait être attribuée à l’utilisation additionnelle de sédatifs. L’incidence d’obstruction des voies aériennes supérieures (7.8 pour cent) était similaire aux études préalables. Un problème vasculaire suite à la procédure fut observé chez 33 patients dont 16 ont requis une correction chirurgicale. Une perforation cardiaque est survenue dans quatre cas provoquant le décès d’un seul patient. La sténose de la valve pulmonaire était la procédure la plus susceptible d’être dilatée et la sténose de la valve aortique la moins susceptible. La kétamine était l’agent anesthésique préféré par les cardiologistes lors des cathétérisations quand une anesthésie générate était requise. Une surveillance vigilante par une équipe anesthésique fut nécessaire durant la procedure. Il faut aussi éviter l’administration de narcotiques si la kétamine est administrée en respiration spontanée.

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Presented in part at the Canadian Anaesthetists’ Society annual meeting in Halifax, June 1988.     

Systemic Lupus Erythematosus and the obstetrical patient — implications for the anaesthetist

Systemic lupus erythematosus (SLE) is a multisystem, chronic inflammatory disease characterized by autoantibody production. The disease is most frequently found in women of childbearing age and therefore may co-exist with pregnancy. The clinical manifestations of the disease are variable and depend on the severity of damage to organ systems such as musculoskeletal, renal, haematological, neurological, cardiac, and respiratory. Many patients require drugs such as aspirin or prednisone. The pregnant patient may experience exacerbations of the disease, neonatal loss, and obstetrical complications such as pre-eclampsia. Patients with the Lupus Anticoagulant are at risk for an abnormal perinatal course. The anaesthetic management will depend on the patient's clinical status and the well-being of the fetus. The patient should be examined to determine the extent of end organ damage, current medications, and the health of the fetus. Laboratory investigations such as a coagulation screen and tests of renal function should be performed before anaesthetic intervention if time permits. A multidisciplinary approach to care of the patient and resources to manage complications are essential to optimize the outcome for both mother and newborn.     

Lumbar and thoracic epidural analgesia via the caudal approach for postoperative pain relief in infants and children

Thirty infants scheduled for a variety of gastrointestinal, genitourinary and thoracic surgical procedures were selected for insertion of lumbar or thoracic epidural catheters via the caudal approach using either an Intracath or a Burron continuous brachial plexus kit. The catheters were inserted with ease by residents in training and no catheter-related complications were encountered. Lidocaine 0.5 per cent with 1:200,000 epinephrine was then injected to assure proper placement of the catheter before narcotics were administered. Postoperative analgesia was adequate in all patients using preservative-free morphine 0.05 mg.kg-1. The mean dosing interval was 15 hr and no episodes of nausea, vomiting, hypotension or histamine release were noted. Urinary retention occurred in two infants and one infant became apnoeic three hours after epidural morphine administration but responded to naloxone and pulmonary ventilation with bag and mask. In conclusion, epidural catheters placed via the caudal approach are a safe and effective means of providing postoperative pain control in infants using preservative-free morphine. However, the use of epidural narcotics in infants less than two years of age is restricted to those who will receive intensive care unit monitoring postoperatively so that if apnoea occurs, rapid intervention can be taken by skilled nursing personnel.     

Post-dural puncture thoracic pain without headache: relief with epidural blood patch

We report two unusual cases of postural, post-dural puncture upper thoracic interscapular backache, without headache, that were relieved by epidural blood patching. There is controversy concerning the aetiology of headache associated with the post-dural puncture syndrome. Mechanisms previously proposed have included traction on pain-sensitive intracranial structures such as the dura or blood vessels, or a vascular mechanism which may be adenosine-receptor mediated. These two cases suggest that traction on cervical or upper thoracic nerve roots should be considered as a possible mechanism of pain in the post-dural puncture syndrome. Nous décrivons deux cas de douleurs posturales dorso-thoraciques interscapulaires consécutives à une perforation de la dure-mère sans céphalée mais soulagées par un blood patch. L’étiologie de la céphalée consécutive à la perforation de la dure-mère n’est pas complètement élucidée. Les mécanismes déjà proposés comprennent la traction sur les structures intracraniennes sensibles à la douleur comme la dure-mère et les vais-seaux sanguins ou un mécanisme vasculaire transmis par les récepteurs de l’adénosine. Ces deux observations suggèrent que la traction exercée sur les racines nerveuses cervicales ou thoraciques hautes devrait être considérée comme un mécanisme potentiel de la douleur du syndrome post-perforation duremèrienne.     

Delayed seizures following sedation with propofol

Seizures occurred in two adolescents approximately six hours after sedation with propofol for bone marrow biopsy. Case #1 was a patient with chronic renal failure, hypertension, and anaemia. Case #2 had just been diagnosed with acute lymphocytic leukaemia. Neither child had experienced seizures before, and both recovered without neurological sequelae. Although other factors may have caused the seizures, the episodes have raised concerns about the safety of propofol for patients travelling home after outpatient surgery. Further study is required to explain the cause of this complication or, at least, to identify risk factors.     

Neuroleptic malignant-like syndrome: a complication of acute organophosphate poisoning

We report a 60-yr-old woman with schizophrenia, who manifested a neuroleptic malignant (NM)-like syndrome after acute organophosphate poisoning (OPP). She attempted suicide by ingesting 40% emulsions of DMTP (S-2,3-dihydro-5-methoxy-2 ?oxo-1,3,4-thiadizol-3-yl-methyl O, O-dimethyl phosphorodithioate) 100 ml. On admission, she was unconscious and demonstrated convulsions, depressed respiratory movements, miosis and profuse salivation. Plasma cholinesterase concentration (842 IU· L^?1) was very low and OPP was diagnosed. She was treated with gastric lavage, atropine and pralidoxime (PAM). By the seventh day after admission, symptoms of OPP disappeared and serum ChE had recovered to a sub-normal level. On the 13th day, she demonstrated coma, high fever (41.0° C) and lead-pipe rigidity. Serum CPK was increased (1631 IV· L^?1). Dantrolene sodium iv was administered for three days. Body temperature began to decrease in 24 hr, and her consciousness, muscle rigidity and other neurological symptoms returned to normal by the 16th day after admission. She was discharged from the hospital without sequelae 55 days after admission. We conclude that OPP can predispose to an NM-like syndrome and that dantrolene may be effective in the management.     

Caesarean section in a diabetic patient with a recent myocardial infarction

This is a report of a 38-yr-old parturient with multiple medical problems including diabetes mellitus, bronchial asthma, chronic myelogenous leukaemia, pre-eclampsia and a recent myocardial infarction. After medical management in the coronary care unit, it was decided to proceed with a Caesarean section. The choice of anaesthetic was made by the patient and had to be modified in accordance with her medical condition. Cardiovascular monitoring included PA catheterisation and transoesophageal echo-cardiography. A general anaesthetic was performed using fentanyl, thiopentone and succinylcholine. The outcome was satisfactory for both parturient and baby. Cette observation porte sur le cas d’une parturiente de 38 ans présentant de multiples problèmes dont un diabète, de l’asthme bronchique, une leucémie myelogène chronique, de la prééclampsie et un infarctus du myocarde récent. Après un séjour à l’unité de soins coronariens pour traitement, une césarienne est décidée. La patiente choisit son anesthésie, choix qu’il faut modifier pour des raison médicales. Le monitorage cardiovasculaire comprend la cathétérisme de l’artère pulmonaire et l’échographie transoesophagienne. L’anesthésie générale est réalisée avec du thiopentone, du fentanyl et de la succinylcholine. Les résultats sont favorables tant pour la mère que pour l’enfant.     

Pathophysiology and prevention of acute renal failure: the role of the anaesthetist

Ischaemic renal tubular damage in the perioperative period can lead to acute renal failure (ARF) with a very high mortality rate (60–75 per cent). Recent research suggests that this tubular injury is caused by an imbalance of the oxygen supply and demand of medullary thick ascending limb (mTAL) tubular cells. High oxygen demand is secondary to active reabsorption of solute which is increased in states of intravascular volume depletion. The restricted supply of oxygen is secondary to the organization of blood flow to the inner medulla. Because the vasa recta loop into the inner medulla and a countercurrent exchange process for oxygen is established, the oxygen tension in this area may normally be as low as 10–20 mmHg. In hypoperfusion stales, mTAL injury occurs and is exacerbated by intravascular volume depletion, hypoxaemia and endothelial cell swelling which reduces perfusion of these vulnerable and metabolically active mTAL cells. The anaesthetist must prevent or attenuate postoperative renal dysfunction by identifying high-risk patients preoperatively, optimizing intravascular volume status and cardiac output in the perioperative period, as well as responding appropriately to hypoperfusion states. Therapeutic implications relate to this pathophysiological sequence and several physiological and pharmacological considerations are discussed. L’ischémie tubulaire rénale dans la période périopératoire peut aboutir à une insuffisance rénale aigue et un taux de mortalité élevé (60–75 pour cent). Les recherches récentes suggèrent que cette lésion tubulaire soil due à un déséquilibre de la demande et de l’apport d’oxygène dans la région médullaire des cellules du tube ascendant (mTAL). La forte demande d’oxygène est secondaire à la réabsortion active de soluté qui est augmentée dans les états d’hypovolémie. L’apport restreint en oxygène est secondaire à l’organisation du flot sanguin dans la médullaire interne. A cause de l’organisation de la vasa recta dans la médullaire interne et du contrecourant, la tension d’oxygène dans cette région peut atteindre normalement des valeurs aussi basses que 10–20 mmHg. Dans les états d’hypoperfusion, des lesions du mTAL surviennent et sont exagérées par l’hypovolémie, l’hypoxémie et l’œdème cellulaire endothélial qui réduit la perfusion de ces cellules vulnérables et mébaboliquement actives. L’anesthésiste doit prévenir on atténuer la dysfonction rénale postopératoire en identifiant les patients à haul risque en periode préopératoire, en optimalisant le volume intravasculaire et le débit cardiaque en période périopératoire et en répondant adéquatement lors des états de bas débit. Les applications thérapeutiques reliées aux conséquences pathophvsiologiques et plusieurs considérations physiologiques et pharmacologiques sont discutées.     

Intraoperative awareness due to malfunction of a Siemens 900B ventilator

A case of intraoperative awareness during a thoracotomy is described. The patient's recall coincided with an intraoperative period during which a Siemens 900B ventilator and a Siemens 952 isoflurane vaporiser were used. Subsequent assessment of this equipment with an anaesthetic agent analyzer revealed that, at the ventilator settings which had been used, the delivered anaesthetic vapour concentration varied greatly from the vaporizer settings. This problem eventually was traced to a malfunctioning inlet control valve on the ventilator. This complication may have been prevented if the end-tidal anaesthetic concentration had been monitored intraoperatively.     

Prophylactic lidocaine for postoperative coronary artery bypass patients,a double-blind,randomized trial

This double-blind controlled study examined the frequency of ventricular arrhythmias (premature ventricular contractions (PVCs) greater than 5.min-1, bigeminy, couplets, ventricular tachycardia, and ventricular fibrillation) in coronary artery bypass graft (CABG) patients during the first 24 hr postoperatively to determine the effect of prophylactic lidocaine on reducing the frequency of ventricular arrhythmias. Patients were included in the study if they had undergone CABG only, and had not received treatment for ventricular arrhythmias before coming off cardiopulmonary bypass. A total of 83 patients were studied and were randomly allocated to 43 in the placebo control group and 40 in the lidocaine-treated group. The results showed that 67 per cent of patients in the placebo group and 33 per cent of patients in the lidocaine treated group had ventricular arrhythmias (P less than 0.005). There was also a significant reduction in ventricular fibrillation and ventricular tachycardia in the lidocaine treated group (P less than 0.01). It is recommended that a routine infusion of lidocaine, 100 mg bolus followed by 2 mg.kg-1, be given to every postoperative coronary artery bypass patient for at least the first 24 hours.     

Changes of expression of endogenous sugar receptors by polymorphonuclear leukocytes after prolonged anaesthesia and surgery

Anaesthesia and surgery are known to depress granulocyte function in the early postoperative period, leading to deterioration of the immune defence against infection. Carbohydrate-lectin interactions may play an important role in the activities of phagocytic cells in that they facilitate initial host defence in the event of microbial antigenic challenge. A panel of biotinylated (neo)glycoproteins (chemically glycosilated carrier proteins) was used to detect endogenous carbohydrate-binding receptors /lectins/, on peripheral blood polymorphonuclear leukocytes of patients undergoing prolonged anaesthesia for replantation surgery. Four hours after induction of anaesthesia, a progressive decline of expression of endogenous sugar receptors on granulocytes was detected using the labelled (neo)glycoproteins lactose-BSA, N-acetyl-D-glucosamine-BSA, D-mannose-BSA, sialic-acid-BSA and D-xylose-BSA. Concomitant changes in peripheral white blood cell counts and the lack of depression in the absence of general anaesthetic agents suggested the existence of a possible relationship between reduced expression of (neo)glycoprotein receptors to impaired granulocyte function and anaesthetic-induced immunodepression.     

Postoperative neuromuscular block following atracurium or alcuronium in children

Postoperative neuromuscular block (NMB) was evaluated in 60 children who received randomly either atracurium or alcuronium to induce and maintain an 85-95 per cent NMB during balanced anaesthesia. The EMG-monitor was turned away from the anaesthetist 10-15 min before the end of surgery. The average NMB was comparable between the groups at the time of reversal with neostigmine 50 micrograms.kg-1 (84 +/- 9 per cent, mean +/- SD) as were the NMB and the train-of-four ratio when the tracheas were extubated on a clinical basis (32 +/- 20 per cent and 50 +/- 18 per cent, respectively). Patients who had been paralyzed with atracurium arrived at the recovery room earlier and on arrival had greater train-of-four ratios than the patients paralyzed with alcuronium (P less than 0.01). Time to a train-of-four ratio of greater than 90 per cent was significantly shorter in the atracurium group (10 +/- 5 min vs 26 +/- 15 min, P less than 0.001). Thus, an intermediate-acting muscle relaxant offers a safer recovery profile of the NMB than a long-acting muscle relaxant in paediatric patients.     

Autonomic hyperreflexia during labour

We present two cases of automatic hyperreflexia (AH) during labour in women with spinal cord damage, in whom AH developed before and after delivery. The AH was successfully controlled using epidural anaesthesia in Case #1, but failed in Case #2. The blood pressure was controlled with nicardipine. However, overdose of nicardipine produces vasodilatation and its side effects include headache, flushing and palpitation similar to AH¹. Considering these effects, we recommend epidural anaesthesia to control AH, because epidural anaesthesia does not only reduce BP, but also blocks the noxious stimuli and relieves the symptoms of AH. Our experience suggests that the epidural catheter can be placed two to three weeks before the date of predicted childbirth, because the onset of labour in a patient with spinal cord damage is difficult to predict and can proceed very rapidly. Also, the epidural catheter is available after the delivery. We recommended the epidural catheter is maintained for 24–48 hr postpartum.