Noninvasive ventilation in myasthenic crisis.

BACKGROUND: Myasthenic crisis (MC) is often associated with prolonged intubation and with respiratory complications. OBJECTIVES: To assess predictors of ventilation duration and to compare the effectiveness of endotracheal intubation and mechanical ventilation (ET-MV) with bilevel positive airway pressure (BiPAP) noninvasive ventilation in MC. DESIGN: Retrospective cohort study. SETTING: Academic research. Patients We reviewed consecutive episodes of MC treated at the Mayo Clinic, Rochester, Minnesota. MAIN OUTCOME MEASURES: Collected information included patients' demographic data, immunotherapy, medical complications, mechanical ventilation duration, and hospital lengths of stay, as well as baseline and preventilation measurements of forced vital capacity, maximal inspiratory and expiratory pressures, and arterial blood gases. RESULTS: We identified 60 episodes of MC in 52 patients. BiPAP was the initial method of ventilatory support in 24 episodes and ET-MV was performed in 36 episodes. There were no differences in patient demographics or in baseline respiratory variables and arterial gases between the groups of episodes initially treated using BiPAP vs ET-MV. In 14 episodes treated using BiPAP, intubation was avoided. The mean duration of BiPAP in these patients was 4.3 days. The only predictor of BiPAP failure (ie, requirement for intubation) was a Pco(2) level exceeding 45 mm Hg on BiPAP initiation (P= .04). The mean ventilation duration was 10.4 days. Longer ventilation duration was associated with intubation (P= .02), atelectasis (P< .005), and lower maximal expiratory pressure on arrival (P= .02). The intensive care unit and hospital lengths of stay statistically significantly increased with ventilation duration (P< .001 for both). The only variable associated with decreased ventilation duration was initial BiPAP treatment (P< .007). CONCLUSIONS: BiPAP is effective for the treatment of acute respiratory failure in patients with myasthenia gravis. A BiPAP trial before the development of hypercapnia can prevent intubation and prolonged ventilation, reducing pulmonary complications and lengths of intensive care unit and hospital stay.

Ophthalmoplegia in tiger snake envenomation.

Herein, we present the case of a 67-year-old grazier who was bitten by a tiger snake and developed coagulopathy and respiratory distress. The patient required intubation and ventilation in intensive care. There was delayed detection of snake envenomation and administration of antivenom. On extubation several days later, gross external ocular paresis was noted. Clinical testing indicated that the ocular pathology was secondary to neurotoxin-mediated presynaptic blockade. The paresis was partially resolved by the time of discharge one week later. The present case report discusses the possible mechanisms for the delayed development of ophthalmoplegia.

An unusual case of hypertensive encephalopathy.

This case report describes a 59-year-old male who presented with headaches, seizures and hypertension followed by coma. Initial magnetic resonance imaging showed T2 hyperintensities typical of Hypertensive Encephalopathy (HE), the follow up scans showed diffusion-weighted imaging (DWI) hyperintensities which is a rare finding in HE. DWI hyperintensities are typically suggestive of areas of cytotoxic damage, and the presence of these changes makes this case unusual, since the pathogenesis of HE is usually due to vasogenic oedema rather than cytotoxic damage of the brain tissue.

Acute small fiber neuropathy following Mycoplasma infection: a rare variant of Guillain-Barré syndrome.

Guillain-Barré syndrome (GBS) is a well-described condition involving the peripheral nervous system. The most well-known form of this disease is acute inflammatory demyelinating polyradiculoneuropathy. Among the different variants of GBS described in the literature, the sensory variant is scantily recognized. There has been a recent attempt to classify the sensory variants of the GBS and bring more objectivity to this diagnostic paradigm. We report a rare sensory variant of GBS presenting with isolated small nerve fiber involvement peripherally in the limbs and associated facial nerve palsy in a patient who had clinical and serological evidence of a preceding Mycoplasma pneumoniae infection. The symptoms resolved gradually with intravenous immunoglobulin therapy. This case adds to the growing literature of the rare form of acute small fiber neuropathy and GBS variants.

Brachial plexopathy associated with Q fever: case report and review of the literature.

Neurologic manifestations of Q fever are predominantly central. We report the case of a 35-year-old man with recurrent fever and motor and sensory deficits in the right C5, C6 territories. Electrophysiological findings were consistent with a right upper-trunk brachial plexopathy or with suprascapular and axillary neuropathies. The patient had full resolution of neurologic symptoms with antibiotic treatment. The association of brachial plexopathy with Q fever infection, described in other rare instances, may merit consideration in individual cases, depending on clinical context.

Predictors of extubation failure in myasthenic crisis.

BACKGROUND: The ideal timing for extubation of patients with myasthenic crisis (MC) and the factors that influence extubation outcome are not well established. OBJECTIVES: To assess the risk of extubation failure in MC and to identify predictors of extubation failure. DESIGN: We reviewed consecutive episodes of MC treated with endotracheal intubation from January 1, 1987, through December 31, 2006. SETTING: Mayo Clinic. Patients Forty patients with 46 episodes of MC underwent endotracheal intubation and mechanical ventilation. MAIN OUTCOME MEASURES: The main outcome measures were extubation failure and reintubation. Extubation failure was defined as reintubation, tracheostomy, or death while intubated. Reintubation was also analyzed as a separate end point. Univariate logistic regression was used to identify predictors of extubation failure and reintubation. RESULTS: Of the 46 episodes of MC, extubation failure occurred in 20 (44%), including 9 of 35 episodes (26%) of reintubation. Male sex, history of previous crisis, atelectasis, and intubation for more than 10 days were associated with extubation failure. Lower pH and lower forced vital capacity on the time of extubation, atelectasis, and bilevel intermittent positive airway pressure use after extubation predicted the need for reintubation. Atelectasis showed the strongest association with both end points. Extubation failure and reintubation were associated with significant prolongation in intensive care unit and hospital length of stay. CONCLUSIONS: Extubation failure is relatively common in patients with MC. Atelectasis is the strongest predictor of this complication.