Juan N. Pulido

Clinical Spectrum, Frequency, and Significance of Myocardial Dysfunction in Severe Sepsis and Septic Shock

OBJECTIVE To determine the frequency and spectrum of myocardial dysfunction in patients with severe sepsis and septic shock using transthoracic echocardiography and to evaluate the impact of the myocardial dysfunction types on mortality. PATIENTS AND METHODS A prospective study of 106 patients with severe sepsis or septic shock was conducted from August 1, 2007, to January 31, 2009. All patients underwent transthoracic echocardiography within 24 hours of admission to the intensive care unit. Myocardial dysfunction was classified as left ventricular (LV) diastolic, LV systolic, and right ventricular (RV) dysfunction. Frequency of myocardial dysfunction was calculated, and demographic, hemodynamic, and physiologic variables and mortality were compared between the myocardial dysfunction types and patients without cardiac dysfunction. RESULTS The frequency of myocardial dysfunction in patients with severe sepsis or septic shock was 64% (n=68). Left ventricular diastolic dysfunction was present in 39 patients (37%), LV systolic dysfunction in 29 (27%), and RV dysfunction in 33 (31%). There was significant overlap. The 30-day and 1-year mortality rates were 36% and 57%, respectively. There was no difference in mortality between patients with normal myocardial function and those with left, right, or any ventricular dysfunction. CONCLUSION Myocardial dysfunction is frequent in patients with severe sepsis or septic shock and has a wide spectrum including LV diastolic, LV systolic, and RV dysfunction types. Although evaluation for the presence and type of myocardial dysfunction is important for tailoring specific therapy, its presence in patients with severe sepsis and septic shock was not associated with increased 30-day or 1-year mortality.

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

IntroductionSpeckle 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.MethodsOver 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.ResultsMortality 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.ConclusionSTE 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.

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.

The Perioperative Management of Patients With Left Ventricular Assist Devices Undergoing Noncardiac Surgery

OBJECTIVE To describe the perioperative management of patients with left ventricular assist devices (LVADs) who require general anesthesia while undergoing noncardiac surgery (NCS) at a single, large tertiary referral center. PATIENTS AND METHODS Electronic medical records from September 2, 2005, through May 31, 2012, were retrospectively reviewed to evaluate the perioperative management and outcomes in LVAD patients undergoing NCS. Patients were included only if they required a general anesthetic and had previously been discharged from the hospital after initial LVAD implantation. RESULTS Thirty-three patients with LVADs underwent general anesthesia for 67 noncardiac operations. The mean ± SD time from LVAD implantation to NCS was 317 ± 349 days. All but 1 patient had axial flow LVADs. Anticoagulation or antiplatelet agents were present within 7 days before NCS in 49 procedures (73%) and reversed in 32 of 49 (65%). No perioperative thrombotic complications related to anticoagulation or antiplatelet reversal were noted. Red blood cell, fresh frozen plasma, and platelet transfusions were administered during 10, 6, and 4 operations, respectively. The only intraoperative complication was surgical bleeding. Postoperative complications were present in 12 patients after NCS and were mainly composed of bleeding. Three patients died within 30 days of NCS, with the causes of death not attributed to NCS. CONCLUSION Patients with LVAD safely underwent NCS in a multidisciplinary setting that included preoperative optimization by cardiologists familiar with LVADs when feasible. Anticoagulation or antiplatelet agents were present preoperatively in most patients with LVADs and were safely reversed when necessary for NCS. The relatively high occurrence of postoperative bleeding is consistent with previous series.

Correlation of left ventricular systolic dysfunction determined by low ejection fraction and 30-day mortality in patients with severe sepsis and septic shock: a systematic review and meta-analysis.

INTRODUCTION The prognostic implications of myocardial dysfunction in patients with sepsis and its association with mortality are controversial. Several tools have been proposed to evaluate cardiac function in these patients, but their usefulness beyond guiding therapy is unclear. We review the value of echocardiographic estimate of left ventricular ejection fraction (LVEF) in the setting of severe sepsis and/or septic shock and its correlation with 30-day mortality. METHODS We conducted a systematic review and meta-analysis to evaluate the prognostic functionality of newly diagnosed LV systolic dysfunction by transthoracic echocardiography on critical ill patients admitted to the intensive care unit with severe sepsis or septic shock. RESULTS A search of EMBASE and PubMed, Ovide MEDLINE, and Cochrane CENTRAL medical databases yielded 7 studies meeting inclusion criteria reporting on a total of 585 patients. The pooled sensitivity of depressed LVEF for mortality was 52% (95% confidence interval [CI], 29%-73%), and pooled specificity was 63% (95% CI, 53%-71%). Summary receiver operating characteristic curve showed an area under the curve of 0.62 (95% CI, 0.58-0.67). The overall mortality diagnostic odd ratio for septic patients with LV systolic dysfunction was 1.92 (95% CI, 1.27-2.899). Statistical heterogeneity of studies was moderate. CONCLUSION The presence of new LV systolic dysfunction associated with sepsis and defined as low LVEF is neither a sensitive nor a specific predictor of mortality. These findings are limited because of the heterogeneity and underpower of the studies. Further research into this method is warranted.

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

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.

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.

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.

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.

Periprocedural Management of 172 Gastrointestinal Endoscopies in Patients with Left Ventricular Assist Devices.

The number of patients with left ventricular assist devices (LVADs) continues to increase, and gastrointestinal (GI) endoscopy is commonly required in this patient population. We retrospectively reviewed the experience of a single tertiary care center in managing patients with LVADs undergoing GI endoscopy between 2006 and 2013. After hospital dismissal from the LVAD placement, 53 patients underwent 172 GI endoscopic procedures. Gastrointestinal bleeding was the indication for endoscopy in 73.8% of patients. Median age at endoscopy was 66 years, and median time from LVAD implantation to initial endoscopy was 271 days (range, 31–1681 days). Anticoagulation or antiplatelet therapy was present within 1 week before 120 of 172 endoscopies (70%) and was withheld or actively reversed in 91 of 120 cases (76%). For sedation/anesthesia during endoscopy, 63 involved care by an anesthesiology team and 109 were performed with nursing sedation protocols. Noninvasive blood pressure techniques (conventional automated cuffs or Doppler pulses) were used for hemodynamic monitoring in 84%, arterial lines in 10%, and no blood pressure recordings documented/charted as inaccurate in 6%. Six patients died within 30 days of endoscopy with one death because of aspiration of blood and multiorgan failure. Patients with LVADs may safely undergo GI endoscopy with various individualized anesthetic/sedation models. Complications after endoscopy likely represent the acuity of this patient population.