Ann Acad Med Singap
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Magnetic resonance imaging (MRI) has become an increasingly popular non-invasive radiological diagnostic procedure, with several distinct advantages over computerised tomography (CT). The images are produced using a strong (1.5-Tesla) magnetic field and radiofrequency (RF) pulses. Due to the effects of the strong magnetic field, certain groups of patients with implanted ferromagnetic objects and women in their first trimester of pregnancy are precluded from undergoing MRI. ⋯ The problems related to anaesthesia in MRI include the constant presence of a strong magnetic field, the RF pulses and their effect on the anaesthesia machine, monitoring devices, magnetically coded material, and loose ferromagnetic objects. In this article, the current availability of MRI-compatible anaesthesia machine, various monitoring devices, and safe conduct of anaesthesia during MRI for patients of all ages are discussed. In addition, the implications of the strong magnetic field on patient resuscitation inside the MRI suite and the recommended procedure for a successful outcome are outlined.
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Considerable advances have been achieved in developing new techniques and equipment for the assessment of neuromuscular transmission during anaesthesia. This paper is a review of the methods currently used in research as well as in daily clinical practice. ⋯ The clinical evaluation of the responses to nerve stimulation, and which stimulation patterns to prefer during onset, maintenance and recovery of neuromuscular block are dealt with, as well as possible errors to be encountered. Arguments are given for routine use of neuromuscular monitoring in the clinical setting, and situations where monitoring of neuromuscular function are of particular importance are noted.
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Ann Acad Med Singap · Jul 1994
Septic shock in a surgical intensive care--validation of multiorgan and APACHE II scores in predicting outcome.
We analysed retrospectively the records of 353 admissions to the National University Hospital's Surgical Intensive Care Unit over a one-year period and found 25 patients with septicaemic shock requiring vasoactive therapy. The mortality rate was 68%. ⋯ Only the APACHE II was a significant predictor of outcome, the rest having poor predictive ability. We conclude that the present scoring systems are too inaccurate for us to base important clinical decisions on.
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Ann Acad Med Singap · Jul 1994
Case ReportsRepeat epidural caesarean section in a patient with cerebral arteriovenous malformation.
Following a previous uneventful pregnancy and caesarean section, a 27-year-old woman with an untreated cerebral arteriovenous malformation presented again with a second pregnancy. While the cerebral haemodynamics during labour and delivery remain unclear, it is best to avoid Valsalva manoeuvres in women with cerebrovascular disease, and therefore caesarean section is usually the preferred method of delivery. ⋯ In the absence of decreased intracranial compliance, epidural anaesthesia is recommended because it avoids the haemodynamic stresses of laryngoscopy and rapid sequence intubation. The anaesthetic management of cerebral arteriovenous malformation in pregnancy is summarised.
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Respiratory catastrophes are the most common cause of anaesthesia-related brain deaths and death. If an airway is recognised to be difficult, endotracheal tube (ETT) intubation should be performed awake. Awake intubation demands proper preparation of the patient. ⋯ If at any point mask ventilation becomes impossible and the patient still cannot be intubated, then transtracheal jet ventilation (TTJV) through a percutaneous IV catheter should be instituted. Once life-sustaining gas exchange is again effected by TTJV, then the patient should either be awakened, a semi-elective tracheostomy or cricothyroidotomy performed or the patient intubated with a special ETT intubation technique. An intubated patient with a known difficult airway should be extubated over a jet stylet.