Using near-infrared spectroscopy myocardial oximetry to monitor myocardial oxygen balance in a swine model of cardiac surgery: a descriptive study.

Monitoring of the adequacy of myocardial protection with cardioplegia is nearly non-existent in clinical cardiac surgical practice and instead relies on well-defined protocols for delivery of cardioplegia often resulting in inadequate protection. We hypothesized that Near Infrared Spectroscopy technology could be useful in the monitoring of the myocardial oxygen state by attaching the monitors to the epicardium in a porcine model of cardiac surgery. The experiments were conducted with 3 different protocols of 2 pigs each for a total of 6 pigs. The objective was to induce episodic, oxygen supply-demand mismatch. Methods for decreased supply included decreasing coronary blood flow, coronary blood hypoxemia, coronary occlusion, hypovolemia, and hypotension. Methods for increase demand included rapid ventricular pacing and the administration of isoproterenol. Changes in myocardial tissue oximetry were measured and this measurement was then correlated with blood hemoglobin saturations of oxygen from coronary sinus blood samples. We found that decreases in myocardial oxygen supply or increases in demand due to any of the various experimental conditions led to decreases in both myocardial tissue oximetry and hemoglobin oxygen saturation of coronary sinus blood with recovery when the conditions were returned to baseline. Correlation between myocardial tissue oximetry and hemoglobin oxygen saturation of coronary sinus blood was moderate to strong under all tested conditions. This may have translational applications as a monitor of adequacy of myocardial protection and the detection of coronary occlusion.

Feasibility of subcutaneous implantable cardioverter-defibrillator implantation with opioid sparing truncal plane blocks and deep sedation.

INTRODUCTION: The subcutaneous implantable cardioverter-defibrillator (S-ICD) is most commonly implanted under general anesthesia (GA), due to the intraoperative discomfort associated with tunneling and dissection. Postoperative pain can be substantial and is often managed with opioids. There is a growing interest in transitioning away from the routine use of GA during S-ICD implantation, while also controlling perioperative discomfort without the use of narcotics. As such, we assessed the feasibility of a multimodal analgesia regimen that included regional anesthesia techniques in patients undergoing S-ICD implantation. METHODS AND RESULTS: Twenty patients received truncal plane block (TBL) immediately before S-ICD implantation. The first 10 patients were implanted under general anesthesia (GA + TBL), and the next 10 patients were implanted under deep sedation (DS + TBL). Additionally, the DS + TBL patients were also prescribed a structured regimen of nonopioid analgesics in the perioperative period. Opioid consumption was calculated as milligram morphine equivalents (MME). In-hospital opioid consumption was significantly lower in the patients implanted with DS + TBL (MME = 0) as compared with patients receiving GA + TBL (MME = 60; P = 0.004). CONCLUSIONS: Subcutaneous ICD implantation with anesthesia-delivered DS and a multimodal anesthetic regimen that includes TBL is feasible and associated with significantly less perioperative opioid consumption.

Needle Migration to the Heart: An Unusual Association of Hemodialysis and Cardiovascular Morbidity.

In this report, we present a unique complication of hemodialysis: the hemodialysis access needle was lost into an arteriovenous fistula. The event went unnoticed for several months. The needle eventually migrated into the right ventricle, requiring an operative retrieval. Loss of the needle was likely unrecognized because of the use of a retracting safety cannula that conceals the needle within a sheath after removal. This case highlights a rare and potentially serious complication of hemodialysis access, demonstrates a possible hazard of retracting safety needles, and reviews the management of foreign bodies that have migrated into the heart.