The Safety and Feasibility of Transesophageal Echocardiography in Patients With Esophageal Stricture.

OBJECTIVES: Expert guidelines consistently list esophageal stricture (ES) as a contraindication to the performance of transesophageal echocardiography (TEE), although anecdotally the authors are aware of patients with ES undergoing TEE without apparent complication. Therefore the authors sought to determine the outcomes of patients with ES who had undergone TEE at their institution. DESIGN: Single-center, retrospective review. SETTING: Academic medical center (clinic and affiliated hospital). PARTICIPANTS: Patients with documented ES who also underwent TEE. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: In a 10-year period, 1,083 TEE reports were generated for 823 patients who had a diagnosis of ES. One case of esophageal perforation occurred (1/1,083 examination reports [0.09%]) in an 85-year-old male with gastroesophageal reflux disease-related ES who had undergone esophageal dilation the same day as the TEE. In 17.2% of the TEE reports reviewed, changes to the conduct of the examination occurred, such as use of a pediatric probe or avoidance of transgastric imaging. In 8% of reviewed examinations, procedural difficulty was recorded. CONCLUSIONS: Patients with nonmalignant ES commonly present for TEE (>100 per year, on average, at the authors' institution). Severe TEE-related esophageal injury rarely occurred in patients with ES. However, changes to the conduct of the TEE examination and procedural difficulty were not infrequent in this group. Clinicians contemplating TEE in patients with ES should prepare for the possibility of altered examination conduct and possible procedural difficulty.

Changes in Right Ventricle Function After Mitral Valve Repair Surgery.

BACKGROUND: Right ventricular (RV) dysfunction can occur after cardiac surgery and persist for years. We assessed perioperative RV systolic function in patients undergoing mitral valve (MV) repair and further compared minimally invasive robotic-assisted mitral valve repair (MIMVr) vs standard 'open' MV repair (MVr). Speckle tracking (RV free wall strain [RVS]) was used as a sensitive echocardiography method to assess RV function. METHODS: Retrospective analysis, over 3 years, of consecutive patients (n = 158) referred to Mayo Clinic (Rochester, MN, USA). Preoperative, pre-discharge and 1 year transthoracic echocardiograms were reviewed. A prospective pilot study was performed for sample size estimation. Primary outcome was RV free wall strain (RVS). RESULTS: Right ventricular free wall strain declined after MV repair surgery (-22.6 ± 7% vs -15 ± 6%, p < 0.001). There were smaller reductions in RVS in MIMVr vs MVr group (-6.0 ± 9% vs -10.3 ± 8%, p < 0.01), which persisted after adjusting for baseline values (RVS treatment effect 1.5%, p = 0.007). There was greater recovery in MIMVr vs MVr group at 1 year follow-up vs pre-surgery values (-3.4 ± 9% vs -8.1 ± 8% respectively, p < 0.001, RVS treatment effect 1.7%, p = 0.001). Bypass time was higher in the MIMVr group (80min ± 22 vs 40min ± 20, p < 0.0001). The echo findings remained significant correcting for age, pulmonary pressures and change in ejection fraction. CONCLUSIONS: Right ventricular systolic dysfunction is common after MV repair surgery. Deterioration in RV contraction is less pronounced following MIMVr vs MVr and is associated with enhanced RV functional recovery at 1 year, albeit not to preoperative levels. This may potentially be associated with clinical functional improvement but further studies are warranted to investigate this.

Impact of New-Onset Left Ventricular Dysfunction on Outcomes in Mechanically Ventilated Patients With Severe Sepsis and Septic Shock.

BACKGROUND:: Left ventricular systolic dysfunction (LVSD) and LV diastolic dysfunction (LVDD) are commonly seen in severe sepsis and septic shock; however, their role in patients with concurrent invasive mechanical ventilation (IMV) is less well defined. METHODS:: This was a prospective observational study on all patients admitted to all the intensive care units (ICUs) at Mayo Clinic, Rochester from August 2007 to January 2009. All adult patients with severe sepsis and septic shock and concurrent IMV without prior heart failure underwent transthoracic echocardiography within 24 hours. Patients with active pregnancy, prior congenital or valvular heart disease, and prosthetic cardiac valves were excluded. Left ventricular systolic dysfunction was defined as LV ejection fraction (LVEF) <50% and LVDD as E/e' >15. Primary outcome was hospital mortality, and secondary outcomes included IMV duration, ICU length of stay (LOS), and total LOS. Two-tailed P value of <.05 was considered statistically significant. RESULTS:: In a total of 106 patients, 58 (54.7%) met our inclusion criteria, with 17 (29.3%), 11 (19.0%), and 5 (8.6%) having LVSD, LVDD, and both, respectively. The cohorts with and without LVSD and LVDD did not differ significantly in their baseline characteristics and laboratory and ventilatory parameters. Compared to those without LVSD, patients with LVSD had higher LV end-systolic diameters but were not different in their left atrial diameters or E/e' ratio. Patients with LVDD had a higher E velocity and E/e' ratio compared to those without LVDD. Hospital mortality was not different in patients with and without LVSD (8 [47%] vs 21 [51%], P = 1.00) and LVDD (8 [73%] vs 21 [45%], P = .18). Secondary outcomes were not different between the 2 groups. CONCLUSION:: Left ventricular systolic or diastolic dysfunction did not influence in-hospital outcomes in patients with severe sepsis and septic shock and concurrent IMV.

Neuromonitoring, Cerebrospinal Fluid Drainage, and Selective Use of Iliofemoral Conduits to Minimize Risk of Spinal Cord Injury During Complex Endovascular Aortic Repair.

PURPOSE: To review outcomes of continuous motor/somatosensory-evoked potential (MEP/SSEP) monitoring, cerebrospinal fluid drainage, and selective use of iliofemoral conduits in patients undergoing endovascular repair of descending thoracic aneurysm (DTA) and thoracoabdominal aortic aneurysms (TAAAs). METHODS: The clinical data of 49 patients (mean age 75±8 years; 38 men) who underwent endovascular repair of DTA and TAAAs (2011-2014) were reviewed. All patients had cerebrospinal fluid drainage, permissive hypertension (mean arterial pressure ≥80 mm Hg), and MEP/SSEP monitoring. There were 44 (90%) patients with TAAAs and 5 (10%) with DTA. Types I and II TAAAs were repaired in staged procedures. Iliofemoral conduits were used for small iliac arteries and to minimize time of lower extremity ischemia in patients with difficult anatomy. In patients with changes in MEP/SSEPs, a standardized protocol was employed to optimize spinal cord perfusion and restore lower extremity blood flow. Endpoints were mortality, spinal cord injury (SCI), and lower extremity ischemic complications. RESULTS: Sixteen (33%) patients had staged TAAA repair. A total of 163 visceral arteries were targeted by fenestrations and branches (mean 3.7±1.0 vessels/patient). Temporary iliofemoral conduits were used in 16 limbs/14 patients. A stable MEP/SSEP was achieved in all patients. Thirty-one (63%) patients had a ≥75% decrease in MEP/SSEP amplitude in 50 limbs starting on average 75±28 minutes after obtaining vascular access. MEP/SSEP amplitude improved with maneuvers in 12 (39%) patients and returned to baseline with restoration of lower extremity flow in all except 1 patient who developed immediate SCI. Thirty-day mortality was 4%. Three (6%) patients had SCI, 2 permanent and 1 temporary at 14 days. There were no lower extremity ischemic complications. CONCLUSION: Neuromonitoring predicted immediate SCI and allowed use of a protocol to optimize spinal cord and lower extremity perfusion during complex endovascular aortic repair. Larger clinical experience is needed to evaluate the efficacy of neuromonitoring to prevent SCI.

Posterior reversible encephalopathy syndrome from induced hypertension during endovascular thoracoabdominal aortic aneurysm repair.

Endovascular repair of thoracoabdominal aortic aneurysm has been increasingly performed using fenestrated and branched endografts. Spinal cord injury is a complication of complex endovascular aortic repair, especially in patients with extensive aortic involvement. Maneuvers commonly used to avoid spinal cord injury include cerebrospinal fluid drainage and induced hypertension. Posterior reversible encephalopathy syndrome is associated with abnormal cerebral autoregulation through endothelial and blood-brain barrier dysfunction; the pathophysiology involves vasogenic edema, and severe hypertension is a recognized trigger. We report on a patient who developed posterior reversible encephalopathy syndrome associated with induced hypertension used to prevent spinal cord injury during endovascular repair of a type II thoracoabdominal aortic aneurysm using fenestrated and branched stent grafts.

Standardized practice design with electronic support mechanisms for surgical process improvement: reducing mechanical ventilation time.

BACKGROUND: Hospital surgical care is complex and subject to unwarranted variation. OBJECTIVE: As part of a multiyear effort, we sought to reduce variability in intraoperative care and management of mechanical ventilation in cardiac surgery. We identified a patient population whose care could be standardized and implemented a protocol-based practice model reinforced by electronic mechanisms. METHODS: In a large cardiac surgery practice, we built a standardized practice model between 2009 and 2011. We compared mechanical ventilation time before (2008) and after (2012) implementation. To ensure groups were comparable, propensity analysis matched patients from the 2 operative years. RESULTS: In 2012, more than 50% of all cardiac surgical patients were managed with our standardized care model; of those, 769 were one-to-one matched with patients undergoing surgery in 2008. Patients had a mix of coronary artery bypass grafting, valve surgery, and combined procedures. Our practice model reduced median mechanical ventilation duration from 9.3 to 6.3 hours (2008 and 2012) (P < 0.001) and intensive care unit length of stay from 26.3 to 22.5 hours (P < 0.001). Reintubation and intensive care unit readmission were unchanged. Variability in ventilation time was also reduced. CONCLUSIONS: We demonstrate that in more than 50% of all cardiac surgical patients, a standardized practice model can be used to achieve better results. Clinical outcomes are improved and unwarranted variability is reduced. Success is driven by clear patient identification and well-defined protocols that are clearly communicated both by electronic tools and by empowerment of bedside providers to advance care when clinical criteria are met.

Outcome prediction in sepsis: speckle tracking echocardiography based assessment of myocardial function.

INTRODUCTION: Speckle tracking echocardiography (STE) is a relatively novel and sensitive method for assessing ventricular function and may unmask myocardial dysfunction not appreciated with conventional echocardiography. The association of ventricular dysfunction and prognosis in sepsis is unclear. We sought to evaluate frequency and prognostic value of biventricular function, assessed by STE in patients with severe sepsis or septic shock. METHODS: Over an eighteen-month period, sixty patients were prospectively imaged by transthoracic echocardiography within 24 hours of meeting severe sepsis criteria. Myocardial function assessment included conventional measures and STE. Association with mortality was assessed over 12 months. RESULTS: Mortality was 33% at 30 days (n = 20) and 48% at 6 months (n = 29). 32% of patients had right ventricle (RV) dysfunction based on conventional assessment compared to 72% assessed with STE. 33% of patients had left ventricle (LV) dysfunction based on ejection fraction compared to 69% assessed with STE. RV free wall longitudinal strain was moderately associated with six-month mortality (OR 1.1, 95% confidence interval, CI, 1.02-1.26, p = 0.02, area under the curve, AUC, 0.68). No other conventional echocardiography or STE method was associated with survival. After adjustment (for example, for mechanical ventilation) severe RV free wall longitudinal strain impairment remained associated with six-month mortality. CONCLUSION: STE may unmask systolic dysfunction not seen with conventional echocardiography. RV dysfunction unmasked by STE, especially when severe, was associated with high mortality in patients with severe sepsis or septic shock. LV dysfunction was not associated with survival outcomes.

Comparison of electroencephalography and cerebral oximetry to determine the need for in-line arterial shunting in patients undergoing carotid endarterectomy.

OBJECTIVE: To compare cerebral near-infrared regional spectroscopy (NIRS) with the 12-lead electroencephalogram for the detection of ischemia during carotid artery clamping for carotid endarterectomy (CEA). DESIGN: Prospective, observational. SETTING: Single, tertiary care center. PARTICIPANTS: Ninety patients older than 18 undergoing elective, unilateral CEA. INTERVENTIONS: In addition to EEG monitoring, all patients underwent continuous blinded NIRS monitoring with sensors placed bilaterally above the supraorbital ridge. MEASUREMENTS AND MAIN RESULTS: Seventeen patients were excluded, leaving 73 patients available for evaluation. Four patients (5.5%) required shunting based on EEG findings. Changes in cerebral oxygen saturation (rSO2) were assessed on the operative side using the average value for the 1 minute prior to cross-clamp and the lowest rSO2 value the first 5 minutes postclamp. Each 1% absolute decrease and each 1% relative decrease from baseline conferred a 50% increase in the need for shunt placement (OR 1.5; 95% CI (1.03-2.26); p = 0.03 and OR 1.4; 95% CI (1.02-1.81); p = 0.04 respectively). Sensitivity, specificity, and positive and negative predictive values were determined using significant cutoffs of≥5% absolute change or≥10% relative change. Positive predictive value was low (<25%) for both absolute and relative changes. CONCLUSIONS: A decrease in rSO2 during carotid cross-clamping for CEA is associated with EEG-determined need for shunting, but the positive predictive value is low. Using the above cutoffs in the current series would have resulted in an increase in the shunt rate by approximately 20% when it was not indicated by EEG.

A novel approach using pulmonary artery catheter-directed rapid right ventricular pacing to facilitate precise deployment of endografts in the thoracic aorta.

OBJECTIVE: Controlled hypotension is critical for precise deployment of endografts in the thoracic aorta and for safe balloon dilation after deployment. We describe a novel approach to rapid right ventricular pacing using a pulmonary artery catheter (PAC) that is placed during the procedure for hemodynamic monitoring. METHODS: The study included 27 patients (20 men and seven women), with a mean age of 74 years, who underwent endograft placement in the thoracic aorta with PAC-directed rapid right ventricular pacing. Hemodynamic parameters, accuracy of deployment, complications related to rapid right ventricular pacing and PAC placement, presence of endoleaks, and postoperative complications were evaluated. RESULTS: PAC-directed rapid right ventricular pacing was performed during endograft deployment and balloon dilation after deployment without technical difficulty. Each patient underwent a median of two pacing episodes (range, 1-4). The length of each pacing episode was a mean of 11 seconds (range, 8-14 seconds). Mean pacing rate was 170 ± 15 beats/min, which achieved an average mean arterial pressure (MAP) of 42 ± 8 mm Hg. After pacing cessation, the recovery time of MAP to prepacing levels was <5 seconds (mean, 2 seconds) in all but one patient. All endografts were precisely deployed at a mean of 2 mm from the intended placement site, and there was no unintentional branch vessel coverage. One patient with severe valvular heart disease died. There were nine endoleaks, one postoperative stroke (4%), and one access wound hematoma (4%). CONCLUSIONS: PAC-directed rapid right ventricular pacing is an effective method of inducing hypotension, enabling precise thoracic endograft deployment and safe balloon dilation after deployment. However, despite these advantages, the technique may be contraindicated in patients with severe valvular or ischemic heart disease.

Percutaneous left ventricular assist device with TandemHeart for high-risk percutaneous coronary intervention: the Mayo Clinic experience.

BACKGROUND: In patients with poor left ventricular function and severe left main or multivessel coronary disease, coronary artery bypass grafting (CABG) surgery has been the preferred therapy. However, a number of these patients are either inoperable or poor surgical candidates due to comorbid conditions and previous cardiac surgical procedures. These patients are generally poor candidates for standard percutaneous coronary intervention (PCI) techniques. A hybrid PCI approach with hemodynamic support may be a viable strategy for these patients. We report our experience using the TandemHeart percutaneous left ventricular assist device during high-risk PCI. METHODS: Retrospective cross-sectional analysis of prospectively collected data in 54 patients undergoing high-risk PCI using the TandemHeart device for support. Hemodynamic and clinical data were collected and analyzed. RESULTS: Baseline clinical characteristics were as follows: mean age 72 ± 1.7 years, males 78%, median ejection fraction 20%, mean serum creatinine 1.6 ± 0.3 2 mg/dL, recent myocardial infarction 52%, COPD 33%, previous CABG 50%, diabetes mellitus 41%, and hypertension 83%. The median SYNTAX score was 33, and the median Jeopardy score was 10. The predicted surgical revascularization mortality was 13% by the Society for Thoracic Surgery risk score and 33% by Euroscore. There was a significant decrease in right and left heart pressures (P < 0.05) with a concomitant increase in the cardiac output from 4.7 to 5.7 L/min (P = 0.03) during TandemHeart support. Left main and multivessel PCI was performed in 62% of patients, and rotablation was used in 48%. Procedural success rate was 97%, whereas 30-day and 6 month survival were 90% and 87%, respectively. Major vascular complications occurred in 13% of cases. None of our patients developed contrast induced nephropathy or needed dialysis. CONCLUSIONS: High-risk PCI with percutaneous left ventricular support using TandemHeart is a viable therapeutic strategy for a select subset of patients at very high risk with standard percutaneous revascularization techniques.

Preoperative gabapentin for acute post-thoracotomy analgesia: a randomized, double-blinded, active placebo-controlled study.

BACKGROUND: The role of preoperative gabapentin in postoperative pain management is not clear, particularly in patients receiving regional blockade. Patients undergoing thoracotomy benefit from epidural analgesia but still may experience significant postoperative pain. We examined the effect of preoperative gabapentin in thoracotomy patients. METHODS: Adults undergoing elective thoracotomy were enrolled in this prospective, randomized, double-blinded, placebo-controlled study, and randomly assigned to receive 600 mg gabapentin or active placebo (12.5 mg diphenhydramine) orally within 2 hours preoperatively. Standardized management included thoracic epidural infusion, intravenous patient-controlled opioid analgesia, acetaminophen and ketorolac. Pain scores, opioid use and side effects were recorded for 48 hours. Pain was also assessed at 3 months. RESULTS: One hundred twenty patients (63 placebo and 57 gabapentin) were studied. Pain scores did not significantly differ at any time point (P = 0.53). Parenteral and oral opioid consumption was not significantly different between groups on postoperative day 1 or 2 (P > 0.05 in both cases). The frequency of side effects such as nausea and vomiting or respiratory depression was not significantly different between groups, but gabapentin was associated with decreased frequency of pruritus requiring nalbuphine (14% gabapentin vs. 43% control group, P < 0.001). The frequency of patients experiencing pain at 3 months post-thoracotomy was also comparable between groups (70% gabapentin vs. 66% placebo group, P = 0.72). CONCLUSIONS: A single preoperative oral dose of gabapentin (600 mg) did not reduce pain scores or opioid consumption following elective thoracotomy, and did not confer any analgesic benefit in the setting of effective multimodal analgesia that included thoracic epidural infusion.

Vasoplegia Following Complex Spine Surgery: Incidence and Risk.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Vasoplegia is a life-threatening form of distributive or vasodilatory shock that is characterized by reduced systemic vascular resistance with resultant hypotension and normal to elevated cardiac output affecting morbidity and mortality. Vasoplegia in the context of Spine Surgery has not been described previously. The purpose of this case series is to determine incidence, risk factors, complications and postoperative outcome in patients with vasoplegia after complex multi-level thoraco-lumbar spine surgery. METHODS: A retrospective review of the electronic medical records at our institution was conducted between January 2014 and June 2018. All patients undergoing multi-level spine surgery (>6 levels) were screened for intraoperative hypotension. Patient demographics, surgical characteristics, neurological status, blood loss, risk factors, medical treatment, complications, hospital course and mortality were collected. All patients included in this study had a minimum follow-up period of 3 months. RESULTS: Out of 8521 surgically treated patients, 994 patients with multi-level thoraco-lumbar spine surgery were identified. A total of 41 patients had intraoperative hypotensive events. Of those, 5 patients with vasoplegia could be identified after elimination of all other potential contributing factors. Vasoplegia did not influence the neurological outcome. One major and three minor complications occurred. All patients showed full recovery. The risk factors identified for vasoplegia include prolonged surgery with osteotomies. CONCLUSIONS: Vasoplegia is a rare condition with an incidence of .6%. Patients experiencing vasoplegia did not appear to experience worse surgical outcomes. The use of special intraoperative hemodynamic monitoring should be considered in selected cases.

WITHDRAWN: A novel approach using pulmonary artery catheter-directed rapid right ventricular pacing to facilitate precise deployment of endografts in the thoracic aorta.

The Publisher regrets that this article is an accidental duplication of an article that has already been published, doi: 10.1016/j.jvs.2011.10.003. The duplicate article has therefore been withdrawn.

Inhaled carbon monoxide attenuates myocardial inflammatory cytokine expression in a rat model of cardiopulmonary bypass.

Carbon monoxide (CO), a by-product of Heme metabolism, is a potent modulator of inflammation. Low dose inhaled CO has demonstrated reduced lung and kidney injury in animal models of cardiopulmonary bypass (CPB). We evaluated the impact of low dose inhaled CO on systemic, pulmonary, and myocardial inflammatory response to CPB in rats. Sixteen male Sprague-Dawley rats underwent CPB for 1 hour. The CO (n = 8) group received inhaled CO at 250 ppm for 3 hours before CPB. The Air (n = 8) group served as the control. Pulmonary mechanics were assessed pre and post CPB. The animals were recovered for 30 minutes post CPB and subsequently sacrificed. Pre CPB and post CPB serum Tumor Necrosis Factor-alpha (TNF-alpha) and Interleukin-10 (IL-10) were analyzed by enzyme-linked immunosorbent assay. Gene expression array and real time quantitative polymerase chain reaction (PCR) analysis was performed on the extracted heart tissue. Baseline characteristics were similar between the groups with the expected exception of carboxyhemoglobin levels (p < or = .001) and oxyhemoglobin saturation (p < or = .01) in Air versus CO treated groups, respectively. Serum TNF-alpha (363 +/- 278 vs. 287 +/- 195;p = .13) and IL-10 (237 +/- 26 vs. 302 +/- 137; p = Not Significant) in Air versus CO groups respectively were not statistically different after CPB, despite showing a trend of inflammatory attenuation. Gene expression array of the myocardial tissue suggested a pattern of inflammatory modulation, which was confirmed by real time quantitative PCR demonstrating IL-10 expression 3.13 times higher (p = .02) in the CO treated group compared to the Air group. These data demonstrate that pretreatment with CO at 250 ppm may have a modulatory effect on the inflammatory response to CPB without compromising hemodynamics or oxygen delivery. Further investigation in a survival model of CPB is warranted.

Perioperative approach to precapillary pulmonary hypertension in non-cardiac non-obstetric surgery.

Pulmonary hypertension (PH) confers a significant challenge in perioperative care. It is associated with substantial morbidity and mortality. A considerable amount of information about management of patients with PH has emerged over the past decade. However, there is still a paucity of information to guide perioperative evaluation and management of these patients. Yet, a satisfactory outcome is feasible by focusing on elaborate disease-adapted anaesthetic management of this complex disease with a multidisciplinary approach. The cornerstone of the peri-anaesthetic management of patients with PH is preservation of right ventricular (RV) function with attention on maintaining RV preload, contractility and limiting increase in RV afterload at each stage of the patient's perioperative care. Pre-anaesthetic evaluation, choice of anaesthetic agents, proper fluid management, appropriate ventilation, correction of hypoxia, hypercarbia, acid-base balance and pain control are paramount in this regard. Essentially, the perioperative management of PH patients is intricate and multifaceted. Unfortunately, a comprehensive evidence-based guideline is lacking to navigate us through this complex process. We conducted a literature review on patients with PH with a focus on the perioperative evaluation and suggest management algorithms for these patients during non-cardiac, non-obstetric surgery.

Impairment of diaphragm muscle force and neuromuscular transmission after normothermic cardiopulmonary bypass: effect of low-dose inhaled CO.

Cardiopulmonary bypass (CPB) is associated with significant postoperative morbidity, but its effects on the neuromuscular system are unclear. Recent studies indicate that even relatively short periods of mechanical ventilation result in significant neuromuscular effects. Carbon monoxide (CO) has gained recent attention as therapy to reduce the deleterious effects of CPB. We hypothesized that 1) CPB results in impaired neuromuscular transmission and reduced diaphragm force generation; and 2) CO treatment during CPB will mitigate these effects. In adult male Sprague-Dawley rats, diaphragm muscle-specific force and neuromuscular transmission properties were measured 90 min after weaning from normothermic CPB (1 h). During CPB, either low-dose inhaled CO (250 ppm) or air was administered. The short period of mechanical ventilation used in the present study ( approximately 3 h) did not adversely affect diaphragm muscle contractile properties or neuromuscular transmission. CPB elicited a significant decrease in isometric diaphragm muscle-specific force compared with time-matched, mechanically ventilated rats ( approximately 25% decline in both twitch and tetanic force). Diaphragm muscle fatigability to 40-Hz repetitive stimulation did not change significantly. Neuromuscular transmission failure during repetitive activation was 60 +/- 2% in CPB animals compared with 76 +/- 4% in mechanically ventilated rats (P < 0.05). CO treatment during CPB abrogated the neuromuscular effects of CPB, such that diaphragm isometric twitch force and neuromuscular transmission were no longer significantly different from mechanically ventilated rats. Thus, CPB has important detrimental effects on diaphragm muscle contractility and neuromuscular transmission that are largely mitigated by CO treatment. Further studies are needed to ascertain the underlying mechanisms of CPB-induced neuromuscular dysfunction and to establish the potential role of CO therapy.

COVID-19 Respiratory Failure: Targeting Inflammation on VV-ECMO Support.

The outbreak of novel coronavirus (SARS-CoV-2) that causes the respiratory illness COVID-19 has led to unprecedented efforts at containment due to its rapid community spread, associated mortality, and lack of immunization and treatment. We herein detail a case of a young patient who suffered life-threatening disease and multiorgan failure. His clinical course involved rapid and profound respiratory decompensation such that he required support with venovenous extracorporeal membrane oxygenation (VV-ECMO). He also demonstrated hyperinflammation (C-reactive protein peak 444.6 mg/L) with severe cytokine elevation (Interleukin-6 peak > 3000 pg/ml). Through treatment targeting hyperinflammation, he recovered from critical COVID-19 respiratory failure and required only 160 hours of VV-ECMO support. He was extubated 4 days after decannulation, had progressive renal recovery, and was discharged to home on hospital day 24. Of note, repeat SARS-CoV-2 test was negative 21 days after his first positive test. We present one of the first successful cases of VV-ECMO support to recovery of COVID-19 respiratory failure in North America.