Hemodynamic Monitoring In The Cardiac Surgical Patient: Comparison of Three Arterial Catheters.

OBJECTIVE: Systemic systolic (SAP) and mean (MAP) arterial pressure monitoring is the cornerstone in hemodynamic management of the cardiac surgical patient, and the radial artery is the most common site of catheter placement. The present study compared 3 different arterial line procedures. It is hypothesized that a 20-G 12.7- cm catheter inserted into the radial artery will be equal to a 20-G 12.7- cm angiocath placed in the brachial artery, and superior to a 20-G 5.00 cm angiocath placed in the radial artery. DESIGN: A prospective randomized control study was performed. SETTING: Single academic university hospital. PARTICIPANTS: Adult patients ≥18 years old undergoing nonemergent cardiac surgery using cardiopulmonary bypass (CPB). INTERVENTIONS: After approval by the Rhode Island Hospital institutional review board, a randomized prospective control study to evaluate 3 different peripheral intraarterial catheter systems was performed: (1) Radial Short (RS): 20-G 5- cm catheter; (2) Radial Long (RL): 20-G 12- cm catheter; and (3) Brachial Long (BL): 20-G 12- cm catheter. MEASUREMENTS AND RESULTS: Gradients between central aortic and peripheral catheters (CA-P) were compared and analyzed before CPB and 2 and 10 minutes after separation from CPB. The placement of femoral arterial lines and administration of vasoactive medications were recorded. After exclusions, 67 BL, 61 RL, and 66 RS patients were compared. Before CPB, CA-P SAP and MAP gradients were not significant among the 3 groups. Two minutes after CPB, the CA-P SAP gradient was significant for the RS group (p = 0.005) and insignificant for BL (p = 0.47) and RL (p = 0.39). Two-group analysis revealed that CA-P SAP gradients are similar between BL and RL (p = 0.84), both of which were superior to RS (p = 0.02 and p = 0.04, respectively). At 10 minutes after CPB, the CA-P SAP gradient for RS remained significant (p = 0.004) and similar to the gradient at 2 minutes. The CA-P SAP gradients increased from 2 to 10 minutes for BL (p = 0.13) and RL (p = 0.06). Two minutes after CPB, the CA-P MAP gradients were significant for the BL (p = 0.003), RL (p < 0.0001), and RS (p < 0.0001) groups. Two-group analysis revealed that the CA-P MAP gradients were lower for the BL group compared with the RL (p = 0.054) and RS (p< 0.05) groups. Ten minutes after CPB, the CA-P MAP gradients in the RL and RS groups remained significant (p < 0.0001) and both greater than the BL group (p = 0.002). A femoral arterial line was placed more frequently in the RS group (8/66 = 12.1%) than in the RL group (3/61 = 4.9%) and the BL group (2/67 = 3.0%). Vasopressin was administered significantly more frequently in the RS group. CONCLUSION: Regarding CA-P SAP gradients, the RL group performed equally to the BL group, both being superior to RS. Regarding CA-P MAP gradients, BL was superior to RL and RS. Clinically, femoral line placement and vasopressin administration were fewer for the BL and RL groups when compared with the RS group. This study demonstrated the benefits of a long (12.7 cm) 20- G angiocath placed in the radial artery.

A Pilot Study to Assess the Clinical Onset of IV Heparin in Interventional Cardiology and Cardiac Surgery.

OBJECTIVES: To determine the onset of heparin anticoagulation, using 2 different measures of activated clotting times (ACT), thromboelastography (TEG; R-time), and anti-Xa levels, after administering low- (100 U/kg) and high- (300 U/kg) dose intravenous (IV) heparin to patients undergoing transcatheter aortic valve replacement (TAVR) and cardiac surgery, respectively. DESIGN: Prospective study. SETTING: Single academic institution. PARTICIPANTS: Patients with normal baseline coagulation presenting for TAVR or cardiac valve surgery. INTERVENTIONS: Coagulation studies were performed at baseline, 30 seconds, 90 seconds, and 180 seconds after IV heparin administration. The tests included iSTAT (iACT) and Hemochron ACT (hACT), TEG R-Time, and anti-Xa levels. At the authors' institution, anti-Xa is the preferred measure of heparin anticoagulation when time permits. ACT, a rapid point- of-care test, is used to assess intraprocedural anticoagulation. MEASUREMENTS AND MAIN RESULTS: After both low- and high-dose heparin, there are peak increases in ACT and anti-Xa at 30 seconds, followed by a decline at 90 seconds and plateau at 180 seconds. The TEG R-time remained elevated (>80 minutes) throughout. For TAVR cases, all anti-Xa was >1.5 IU/mL, and was associated with an iACT >180 seconds and an hACT >200 seconds. For cardiac valve surgery cases, all anti-Xa was >2.4 and associated with an iACT >420 seconds and and hACT >340 seconds. Compared with hACT, iACTs were significantly lower at all time points after low-dose heparin, but not after high-dose heparin. CONCLUSIONS: In this pilot study, heparin anticoagulation was detected as early as 30 seconds after IV administration, based on ACT, anti-Xa levels, and TEG R-time.

Sympathetic Blockade for the Management of Refractory Ventricular Tachycardia: A Case Report.

A 64-year-old man with a history of nonischemic cardiomyopathy (NICM) presented with electrical storm (ES). Episodes of ventricular tachycardia (VT) persisted despite endocardial catheter ablations and exhaustive pharmacotherapy. We used alternating regional anesthesia techniques, left stellate ganglion block, and proximal intercostal block to reduce sympathetic input to the heart, resulting in a significant decrease in VT burden. By using alternating catheter locations, we were able to maintain continuous sympathetic blockade for 31 days and bridge the patient to a successful orthotopic heart transplant.

Andexanet Alfa for Urgent Reversal of Apixaban Before Aortic Surgery Requiring Cardiopulmonary Bypass: A Case Report.

Andexanet alfa is a recombinant factor Xa decoy molecule capable of reversing direct and indirect factor Xa-inhibiting anticoagulants. We present an adult patient on apixaban for nonvalvular atrial fibrillation who required urgent reoperative aortic surgery for an aortic root pseudoaneurysm. Apixaban was reversed with andexanet alfa. A second dose of andexanet alfa was required before surgical incision for persistently elevated antifactor Xa levels. Intraoperative management required use of cardiopulmonary bypass (CPB). No major adverse cardiovascular, cerebrovascular, hemorrhagic, or thromboembolic events were observed.

Preoperative QTc Interval is Not Associated With Intraoperative Cardiac Events or Mortality in Liver Transplantation Patients.

OBJECTIVES: The primary objective of this study was to determine whether liver transplantation recipients with preoperative prolonged corrected (QTc) intervals have a higher incidence of intraoperative cardiac events and/or postoperative mortality compared with their peers with normal QTc intervals. DESIGN: This was a retrospective cohort study. SETTING: Single academic hospital in New York, NY. PARTICIPANTS: Patients undergoing liver transplantation between 2007 and 2016. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data relating to all liver transplantation recipients with preoperative electrocardiograms were queried from an institutional anesthesia data warehouse and electronic medical records. Primary outcomes were a composite outcome of intraoperative cardiac events and postoperative mortality. Patients with a prolonged QTc interval (>450 ms for men, >470 ms for women) did not demonstrate an association with intraoperative cardiac events, 30- or 90-day mortality, in-hospital mortality, or overall mortality compared with recipients in the normal QTc interval group. A prolonged QTc was found to be associated with increased anesthesia time, surgical time, length of hospital stay, and incidence of fresh frozen plasma and platelets transfusion. CONCLUSIONS: Prolonged QTc interval is not associated with an increased incidence of intraoperative cardiac events or mortality in liver transplantation recipients. The demonstrated correlation among QTc length and Model for End-stage Liver Disease score, blood component requirements, surgical and anesthetic times, and hospital length of stay likely represents the association between QTc length and severity of liver disease.

Successful Management of a Patient With X-Linked Myotubular Myopathy for Scoliosis Surgery and Previous Cardiac Arrest After Prone Positioning: A Case Report.

A 15-year-old boy with X-linked myotubular myopathy associated with severe hypotonia and pectus excavatum presented for posterior spinal fusion of T2-sacrum because of rest pain and severe progressive neuromuscular scoliosis. Previously, he experienced 2 separate instances of cardiac arrest after prone positioning under general anesthesia. A preoperative computed topography angiogram in the supine and prone positions revealed inferior vena cava and right ventricular outflow tract obstruction on prone positioning. Successful positioning and posterior spinal fusion occurred by staging the procedure, correction of volume status, early use of vasoactive and inotropic agents, and oblique prone positioning.

Poor Performance on a Preoperative Cognitive Screening Test Predicts Postoperative Complications in Older Orthopedic Surgical Patients.

BACKGROUND: The American College of Surgeons and the American Geriatrics Society have suggested that preoperative cognitive screening should be performed in older surgical patients. We hypothesized that unrecognized cognitive impairment in patients without a history of dementia is a risk factor for development of postoperative complications. METHODS: We enrolled 211 patients 65 yr of age or older without a diagnosis of dementia who were scheduled for an elective hip or knee replacement. Patients were cognitively screened preoperatively using the Mini-Cog and demographic, medical, functional, and emotional/social data were gathered using standard instruments or review of the medical record. Outcomes included discharge to place other than home (primary outcome), delirium, in-hospital medical complications, hospital length-of-stay, 30-day emergency room visits, and mortality. Data were analyzed using univariate and multivariate analyses. RESULTS: Fifty of 211 (24%) patients screened positive for probable cognitive impairment (Mini-Cog less than or equal to 2). On age-adjusted multivariate analysis, patients with a Mini-Cog score less than or equal to 2 were more likely to be discharged to a place other than home (67% vs. 34%; odds ratio = 3.88, 95% CI = 1.58 to 9.55), develop postoperative delirium (21% vs. 7%; odds ratio = 4.52, 95% CI = 1.30 to 15.68), and have a longer hospital length of stay (hazard ratio = 0.63, 95% CI = 0.42 to 0.95) compared to those with a Mini-Cog score greater than 2. CONCLUSIONS: Many older elective orthopedic surgical patients have probable cognitive impairment preoperatively. Such impairment is associated with development of delirium postoperatively, a longer hospital stay, and lower likelihood of going home upon hospital discharge.

Preoperative Cognitive Stratification of Older Elective Surgical Patients: A Cross-Sectional Study.

BACKGROUND: Preexisting cognitive impairment is emerging as a predictor of poor postoperative outcomes in seniors. We hypothesized that preoperative cognitive screening can be performed in a busy preadmission evaluation center and that cognitive impairment is prevalent in elective geriatric surgical patients. METHODS: We approached 311 patients aged 65 years and older presenting for preoperative evaluation before elective surgery in a prospective, observational, single-center study. Forty-eight patients were ineligible, and 63 declined. The remaining 200 were randomly assigned to the Mini-Cog (N =100) or Clock-in-the-Box [CIB; N = 100)] test. Study staff administered the test in a quiet room, and 2 investigators scored the tests independently. Probable cognitive impairment was defined as a Mini-Cog ≤ 2 or a CIB ≤ 5. RESULTS: The age of consenting patients was 73.7 ± 6.4 (mean ± SD) years. There were no significant differences between patients randomly assigned to the Mini-Cog and CIB test in age, weight, gender, education, ASA physical status, or Charlston Index. Overall, 23% of patients met criteria for probable cognitive impairment, and prevalence was virtually identical regardless of the test used; 22% screened with the Mini-Cog and 23% screened with the CIB scored as having probable cognitive impairment (P = 1.0 by χ analysis). Both tests had good interrater reliability (Krippendroff α = 0.86 [0.72-0.93] for Mini-Cog and 1 for CIB). CONCLUSIONS: Preoperative cognitive screening is feasible in most geriatric elective surgical patients and reveals a substantial prevalence of probable cognitive impairment in this population.

Bicephalic amphiphile architecture affects antibacterial activity.

A series of cationic amphiphiles, each with an aromatic core, was prepared and investigated for antimicrobial properties. The synthesized amphiphiles in this study are bicephalic (double-headed) in that they each possess two trimethylammonium head groups and a single linear alkoxy tail. Minimum inhibitory and minimum bactericidal concentrations of these amphiphiles were in the low micromolar range. Antimicrobial activities are highly sensitive to the chain length of the hydrophobic region, and modestly reliant on the relative positioning of the head groups on the aromatic core. These trends were more pronounced in time kill assays, wherein longer chain compounds required significantly shorter times to completely kill bacteria. Microscopy suggested that the mode of cell death was lysis. Strong inhibition was observed with both biscationic compounds and monocationic comparisons against Gram-positive bacteria; only biscationic amphiphiles maintained good activity versus the Gram-negative bacteria tested. These observations provide direction for future antimicrobial structural investigations.

Skin microbes on frogs prevent morbidity and mortality caused by a lethal skin fungus.

Emerging infectious diseases threaten human and wildlife populations. Altered ecological interactions between mutualistic microbes and hosts can result in disease, but an understanding of interactions between host, microbes and disease-causing organisms may lead to management strategies to affect disease outcomes. Many amphibian species in relatively pristine habitats are experiencing dramatic population declines and extinctions due to the skin disease chytridiomycosis, which is caused by the chytrid fungus Batrachochytrium dendrobatidis. Using a randomized, replicated experiment, we show that adding an antifungal bacterial species, Janthinobacterium lividum, found on several species of amphibians to the skins of the frog Rana muscosa prevented morbidity and mortality caused by the pathogen. The bacterial species produces the anti-chytrid metabolite violacein, which was found in much higher concentrations on frog skins in the treatments where J. lividum was added. Our results show that cutaneous microbes are a part of amphibians' innate immune system, the microbial community structure on frog skins is a determinant of disease outcome and altering microbial interactions on frog skins can prevent a lethal disease outcome. A bioaugmentation strategy may be an effective management tool to control chytridiomycosis in amphibian survival assurance colonies and in nature.

Amphibian chemical defense: antifungal metabolites of the microsymbiont Janthinobacterium lividum on the salamander Plethodon cinereus.

Disease has spurred declines in global amphibian populations. In particular, the fungal pathogen Batrachochytrium dendrobatidis has decimated amphibian diversity in some areas unaffected by habitat loss. However, there is little evidence to explain how some amphibian species persist despite infection or even clear the pathogen beyond detection. One hypothesis is that certain bacterial symbionts on the skin of amphibians inhibit the growth of the pathogen. An antifungal strain of Janthinobacterium lividum, isolated from the skin of the red-backed salamander Plethodon cinereus, produces antifungal metabolites at concentrations lethal to B. dendrobatidis. Antifungal metabolites were identified by using reversed phase high performance liquid chromatography, high resolution mass spectrometry, nuclear magnetic resonance, and UV-Vis spectroscopy and tested for efficacy of inhibiting the pathogen. Two metabolites, indole-3-carboxaldehyde and violacein, inhibited the pathogen's growth at relatively low concentrations (68.9 and 1.82 microM, respectively). Analysis of fresh salamander skin confirmed the presence of J. lividum and its metabolites on the skin of host salamanders in concentrations high enough to hinder or kill the pathogen (51 and 207 microM, respectively). These results support the hypothesis that cutaneous, mutualistic bacteria play a role in amphibian resistance to fungal disease. Exploitation of this biological process may provide long-term resistance to B. dendrobatidis for vulnerable amphibians and serve as a model for managing future emerging diseases in wildlife populations.