BackgroundPerioperative dynamic left ventricular outflow obstruction associated with systolic anterior motion of the mitral valve is well recognized as a cause for unexplained sudden hypotension in perioperative settings, even without underlying heart diseases such as hypertrophic obstructive cardiomyopathy. We treated a patient who experienced sudden hypoxemia without severe hypotension during emergence from anesthesia after an uneventful laparoscopic cholecystectomy.Case presentationA 65-year-old female patient with a history of hypertension presented a sudden decrease in oxygen saturation to 80% after an uneventful cholecystectomy. Although a portable chest radiograph showed bilateral hilar pulmonary infiltrates consistent with pulmonary edema, we explored the underlying cause, i.e., systolic anterior motion of the mitral valve and left ventricular outflow tract obstruction with bedside transthoracic echocardiography. We speculate that dynamic mitral regurgitation resulted in pulmonary edema and, thereby, hypoxemia in this case without severe hypotension.ConclusionsCareful bedside examination with transthoracic echocardiography was useful in making diagnosis and in guiding appropriate therapy for this patient. Clinicians should be aware that systolic anterior motion of the mitral valve may present as unexplained sudden hypoxemia in the perioperative setting.Electronic supplementary materialThe online version of this article (doi:10.1186/s12871-015-0031-y) contains supplementary material, which is available to authorized users.

Supraclavicular brachial plexus block is a common anesthetic technique performed for surgery of the upper extremities. We experienced a case of acute hypercapnic respiratory distress with loss of consciousness during creation of an arteriovenous fistula under ultrasound-guided supraclavicular brachial plexus block using 30 mL of 0.75 % ropivacaine. We detected ipsilateral hemidiaphragmatic paralysis by means of M-mode ultrasonography of the block. We thus speculate that phrenic nerve palsy caused by supraclavicular brachial plexus block was the underlying mechanism of the event. Bedside ultrasonography played a pivotal role in making a differential diagnosis and in managing this patient.

Background Glossopharyngeal neuralgia is a condition that causes severe pain in the throat during swallowing. Although carbamazepine is a viable option for treating glossopharyngeal neuralgia, there are minimal data regarding the effect of alternative agents to treat it. We report on glossopharyngeal neuralgia, which is successfully controlled by levetiracetam. Presentation A woman in her 70s checked into our hospital with a chief complaint of neck pain lasting 5 years. She had a history of carbamazepine-induced interstitial pneumonia. As a result, we prescribed oral levetiracetam 1000 mg daily in addition to mirogabalin, which was previously prescribed. This effectively reduced the numerical rating scale from 9 to 1 with no adverse effects. Finally, she underwent microvascular decompression, and her symptoms were resolved. Conclusion Levetiracetam may be an option for patients with glossopharyngeal neuralgia who cannot receive carbamazepine. However, levetiracetam is for off-label use according to the Japanese medical system.