Halothane treatment of severe asthma to avoid mechanical ventilation

Abstract

SummaryA 47-year-old female patient had a subclinical superior vena caval syndrome which developed into the 'full blown' acute condition when she was placed into the left lateral position after mediastinoscopy. She developed airway obstruction requiring urgent re-intubation and subsequent admission to the intensive care unit. This subclinical condition might have been suspected pre-operatively if closer attention had been paid to the history, physical examination and review of the computerised axial tomography scan: she had a history of intermittent dyspnoea, wheeze and cough which was worse on waking and improved as the day progressed, she had a positive Pemberton's sign and the computerised axial tomography scan showed that the lesion was encroaching on the superior vena cava. Vincent's Hospital, Elm Park, Dublin 4, Ireland Accepted: 14 April 1997 There is an increasing emphasis on the role of the anaesthetist as a peri-operative physician [1]. Patients with significant medical pathology regularly undergo complex surgical interventions and the anaesthetist may be involved in the pre-operative evaluation and in the planning of intensive or high-dependency care and postoperative pain management. Given the escalating costs incurred in the provision of intensive care, it is likely that strategies leading to a reduction in admission to the intensive care unit will receive more attention in the future. One such strategy is the improved quality of pre-operative evaluation. Possibly contrary to this, many patients, particularly if admitted as a daycase, now complete questionnaires to identify peri-operative problems and assist speedy pre-operative assessment. Such questionnaires give information that is factually correct but without the details which would have been forthcoming from a complementary medical interview.Pre-operative patients are usually seen by the anaesthetist on the night before surgery. To aid this process in our hospital, a patient proforma is completed by the house officer highlighting essential pre-operative information. This is an efficient alternative to perusal of the patient's chart but it is not foolproof. In the case that we report, the information provided formed the basis for a brief factual interview, the patient was examined, anxieties were allayed and premedication was prescribed. The interview had proceeded in standard fashion. However, as a consequence of this system of assessment, several useful pieces of clinical information were not obtained. Case historyA 47-year-old female was booked for elective mediastinoscopy and biopsy. At the pre-operative visit, the following details were noted: she had a 6-week history of intermittent dyspnoea, wheeze and cough with no past medical history; there was a strong family history of asthma; she was not taking any medication; she had had a significant allergic reaction to contrast medium during the computerised axial tomography (CT) scan 1 week previously with extensive erythema lasting 24 h. On examination she weighed 86 kg, her airway was c...

Sevoflurane Inhalation for Severe Bronchial Obstruction in Infants with Bronchiolitis

“…Although effective, these two anesthetics have enjoyed limited use in clinical practice owing to their adverse effects, including hepatitis and lifethreatening arrhythmias (9,10). The newer inhaled anesthetic, sevoflurane possesses airway smooth muscle relaxing properties (bronchodilation) similar to those of halothane and isoflurane without their major adverse effects.…”

“…Although long-term use of sevoflurane might cause organ dysfunction, such as renal tubular injury, hepatotoxicity and neuropathy (14), accumulating evidence suggests that prolonged sevoflurane inhalation is safe in adults and infants (7)(8)(9)(10)(11).…”

“…Similarly, Schultz described a 26-yearold woman in whom status asthmaticus responded to positive pressure ventilation and sevoflurane inhalation (8%) after conventional therapy had failed (salbutamol, epinephrine and methylprednisolone) (8). Halogenated gases have also been given during non-invasive ventilation, either through a face mask (9) or via a helmet (10) at subanesthetic doses (0.25%). In the pediatric literature, evidence documenting the effectiveness of sevoflurane inhalation is limited to a single case report describing a 3-month-old boy presenting with post-extubation status asthmaticus (11).…”

Uso de terapias não convencionais no manejo da crise aguda de asma refratária

“…Seu efeito broncodilatador faz-se por bloqueio vagal e por ação direta sobre a musculatura lisa brônquica contraída, ou seja, em broncoespasmo, sendo oportuno na crise asmática (10) . Vários relatos de caso confirmam a utilidade desse anestésico no tratamento de crises refratá-rias ao tratamento clínico intensivo e, mais recentemente, Padkin et al utilizaram ventilação com halotano para evitar a intubação de uma paciente de 41 anos em insuficiência respiratória aguda por crise asmática (11)(12)(13) . Outros agentes anestésicos voláteis, como isoflurano e sevoflurano, também são eficazes como broncodilatadores, sendo que o último causa menos complicações cardiovasculares que o halotano.…”

“…No entanto, a manutenção do broncoespasmo, apesar do tratamento farmacológico, pode prolongar a ventilação mecânica, causar altas pressões em vias aéreas e maior risco de barotrauma. Em algumas dessas situações, podemos lançar mão de métodos não convencionais para tratamento do broncoespasmo, como o uso de agentes anestésicos voláteis e lavado brônquico por broncoscopia para retirada de tampões de secreção (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13) .…”