Decreases in Mixed Venous Blood O2 Saturation in Cardiac Surgery Patients Following Extubation.

BACKGROUND: Decreases in mixed venous O2 saturation (SvO2) have been reported to occur in postcardiac surgery patients during weaning from mechanical ventilation. Our aim was to establish whether the physiological mechanism responsible for this phenomenon was a decrease in systemic O2 delivery (DO2) or an increase in global O2 consumption (V˙ O 2). METHODS: We studied 21 mechanically ventilated, postoperative cardiac patients for 30 minutes before and 60 minutes after extubation. We monitored continuously arterial O2 saturation by pulse oximetry (SaO2) and central venous O2 saturation (ScvO2) with an oximetry catheter. Mixed venous O2 saturation (SvO2) and cardiac output were also measured continuously with an oximetry pulmonary artery catheter. Systemic O2 delivery and V˙ O 2 were calculated according to accepted formulae. RESULTS: Immediately following extubation, ScvO2 and SvO2 decreased rapidly (P < .01). Systemic O2 consumption increased from 65 (57) mL·min-1 to 194 (66) mL·min-1 (P < .05) with no changes in DO2. Consequently, systemic O2 extraction rose from 38% (8%) to 45% (9%; P < .01). Preoperative left ventricular ejection fraction correlated with the decline in SvO2 postextubation. All patients weaned successfully. CONCLUSIONS: Decreases in SvO2 after discontinuation of ventilatory support in postcardiac surgery patients occur as V˙ O 2 increases in response to greater energy requirements by muscles of ventilation that are not initially matched by increases in DO2.

Metastatic primary pulmonary melanoma successfully treated with checkpoint inhibitors.

Our patient is a 69-year-old man who presented to the emergency department with left-sided hemiparesis that started 4 hours prior to presentation. Brain CT showed right basal ganglia and internal capsule haemorrhagic strokes. MRI revealed multiple brain lesions suspicious for metastases. Further workup revealed a 5 cm lung mass and a 1 cm pancreatic nodule. Biopsy of both pulmonary and pancreatic lesions was consistent with melanoma and was similar histologically. The patient underwent cyberknife stereotactic radiosurgery to the brain metastases followed by immunotherapy with pembrolizumab, and then by nivolumab and ipilimumab. The patient remains free of disease progression 2 years after treatment.

Laparoscopic repair of a left paraduodenal hernia presenting with acute bowel obstruction: report of a case.

An internal hernia is any protrusion of a solid organ or a hollow viscus through a defect within the abdominal cavity. Paraduodenal hernias (PDHs) are rare; however, they are the most common form of internal hernias. We present a case of a left PDH in a 59-year-old healthy woman who presented with acute bowel obstruction. The PDH was diagnosed preoperatively using computed tomography scan. Laparoscopic exploration of the abdomen was then performed for reduction of the hernia. Using this approach, we managed to close the defect with intracorporeal continuous suturing with the aim of avoiding future incarceration. The patient was discharged 60 hours postoperation in a good condition, compared with 3 to 28 days postoperation reported in most of the literature. Our search of the english language literature revealed only 16 reported cases of laparoscopic repair of PDH. We believe that laparoscopic treatment of PDH in experienced hands is recommended in selected cases as it decreases the morbidity and significantly shortens the hospital stay.