Case 290 Medical History A 47 year-old female patient undergoes right shoulder arthroscopy for shoulder impingement syndrome treatment, performed under general balanced anesthesia associated with interscalene brachial plexus block via Winnie technique. Soon after waking up and being extubated, the patient presented sudden dyspnea, tachypnea and right-sided intercostal retraction and absence of breathing sounds. The patient mantained a blood oxygen saturation of 96% under 2 L/min supplemental oxygen. Posteroanterior and lateral chest radiographic images were obtained. Posteroanterior chest radiograph.Lateral chest radiograph.Question:After analysing the patient's history and the images, what is the most likely cause for the patient's dyspnea? Right-sided iatrogenic pneumothorax. Right-sided Horner's syndrome. Right-sided diaphragmatic paralisys. Right-sided diaphragmatic eventration. Test Question (Medical residency examination question - UFSM 2017) In the upper thorax, the phrenic nerve is located: Over the middle scalene muscle. Over the anterior scalene muscle. Between the anterior and the middle scalene muscles. Between the posterior and middle scalene muscles. None. Time is Up! Time's up