Imipenem/relebactam pharmacokinetics in critically ill patients supported on extracorporeal membrane oxygenation.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is a life-saving modality but has the potential to alter the pharmacokinetics (PK) of antimicrobials. Imipenem/cilastatin/relebactam is an antibiotic with utility in treating certain multi-drug resistant Gram-negative infections. Herein, we describe the population pharmacokinetics of imipenem and relebactam in critically ill patients supported on ECMO. METHODS: Patients with infection supported on ECMO received 4-6 doses of imipenem/cilastatin/relebactam per current prescribing information based on estimated creatinine clearance. Blood samples were collected following the final dose of the antibiotic. Concentrations were determined via LC-MS/MS. Population PK models were fit with and without covariates using Pmetrics. Monte Carlo simulations of 1000 patients assessed joint PTA of fAUC0-24/MIC ≥ 8 for relebactam, and ≥40% fT > MIC for imipenem for each approved dosing regimen. RESULTS: Seven patients supported on ECMO were included in PK analyses. A two-compartment model with creatinine clearance as a covariate on clearance for both imipenem and relebactam fitted the data best. The mean ±â€Šstandard deviation parameters were: CL0, 15.21 ±â€Š6.52 L/h; Vc, 10.13 ±â€Š2.26 L; K12, 2.45 ±â€Š1.16 h-1 and K21, 1.76 ±â€Š0.49 h-1 for imipenem, and 6.95 ±â€Š1.34 L/h, 9.81 ±â€Š2.69 L, 2.43 ±â€Š1.13 h-1 and 1.52 ±â€Š0.67 h-1 for relebactam. Simulating each approved dose of imipenem/cilastatin/relebactam according to creatinine clearance yielded PTAs of ≥90% up to an MIC of 2 mg/L. CONCLUSIONS: Imipenem/cilastatin/relebactam dosed according to package insert in patients supported on ECMO is predicted to achieve exposures sufficient to treat susceptible Gram-negative isolates, including Pseudomonas aeruginosa.

Outcomes With Single-Site Dual-Lumen Versus Multisite Cannulation for Adults With COVID-19 Respiratory Failure Receiving Venovenous Extracorporeal Membrane Oxygenation.

OBJECTIVES: To determine whether multisite versus single-site dual-lumen (SSDL) cannulation is associated with outcomes for COVID-19 patients requiring venovenous extracorporeal membrane oxygenation (VV-ECMO). DESIGN: Retrospective analysis of the Extracorporeal Life Support Organization Registry. Propensity score matching (2:1 multisite vs SSDL) was used to control for confounders. PATIENTS: The matched cohort included 2,628 patients (1,752 multisite, 876 SSDL) from 170 centers. The mean ( sd ) age in the entire cohort was 48 (11) years, and 3,909 (71%) were male. Patients were supported with mechanical ventilation for a median (interquartile range) of 79 (113) hours before VV-ECMO support. INTERVENTIONS: None. MEASUREMENTS: The primary outcome was 90-day survival. Secondary outcomes included survival to hospital discharge, duration of ECMO support, days free of ECMO support at 90 days, and complication rates. MAIN RESULTS: There was no difference in 90-day survival (49.4 vs 48.9%, p = 0.66), survival to hospital discharge (49.8 vs 48.2%, p = 0.44), duration of ECMO support (17.9 vs 17.1 d, p = 0.82), or hospital length of stay after cannulation (28 vs 27.4 d, p = 0.37) between multisite and SSDL groups. More SSDL patients were extubated within 24 hours (4% vs 1.9%, p = 0.001). Multisite patients had higher ECMO flows at 24 hours (4.5 vs 4.1 L/min, p < 0.001) and more ECMO-free days at 90 days (3.1 vs 2.0 d, p = 0.02). SSDL patients had higher rates of pneumothorax (13.9% vs 11%, p = 0.03). Cannula site bleeding (6.4% vs 4.7%, p = 0.03), oxygenator failure (16.7 vs 13.4%, p = 0.03), and circuit clots (5.5% vs 3.4%, p = 0.02) were more frequent in multisite patients. CONCLUSIONS: In this retrospective study of COVID-19 patients requiring VV-ECMO, 90-day survival did not differ between patients treated with a multisite versus SSDL cannulation strategy and there were only modest differences in major complication rates. These findings do not support the superiority of either cannulation strategy in this setting.

Outcomes by cannulation methods for venovenous extracorporeal membrane oxygenation during COVID-19: A multicenter retrospective study.

In a multicenter, retrospective analysis of 435 patients with refractory COVID-19 placed on V-V ECMO, cannulation by a single, dual-lumen catheter with directed outflow to the pulmonary artery was associated with lower inpatient mortality.

Application and outcomes of extracorporeal life support in emergency general surgery and trauma.

BACKGROUND: We analyzed the use of Extracorporeal Membranous Oxygenation (ECMO) in acute care surgery patients at our Level-1 trauma center. We hypothesized that this patient population has improved ECMO outcomes. METHODS: This was a retrospective analysis of emergency general surgery and trauma patients placed on ECMO between the periods of October 2013 and February 2020. There were 10 surgical and 12 trauma patients studied, who eventually required ECMO support. ECMO support and ECMO type/modality were analyzed with injury and survival prognostic scores examined. MAIN RESULTS: Overall, 16 of the 22 patients survived to hospital discharge, for a survival rate of 73%. Mean age was 34.18 years. Mean hospital length of stay was 23.4 days with mean days on ECMO equal to 7.5. The net negative fluid balance was 5.36 L. CONCLUSIONS: The survival of our ECMO cohort is notably higher than previously cited studies. Our group demonstrated decreased length of time on ECMO, decreased length of stay in the hospital, and similar rates of complications compared to prior reports. ECMO is a useful modality in acute care surgical patients and should be considered in these patient populations. Our focus on net negative fluid balance for ECMO patients demonstrates improved survival. ECMO should be considered early in surgical patients and early in advanced trauma life support.

Air Medical Transport of Patients Diagnosed With Confirmed Coronavirus Disease 2019 Infection Undergoing Extracorporeal Membrane Oxygenation: A Case Review and Lessons Learned.

The coronavirus disease 2019 pandemic disrupted health care delivery in every respect, including critical care resources and the transport of patients requiring extracorporeal membrane oxygenation. Innovative solutions allowing for safe helicopter air transport of these critical patients is needed because extracorporeal membrane oxygenation resources are only available in specialty centers. We present a case demonstrating the interfacility collaboration of care for a patient with coronavirus disease 2019 infection and the lessons learned from the air transport. Careful planning, coordination, communication, and teamwork contributed to the safe transport of this patient and several others subsequently.

Incidental COVID-19 in a heart-kidney transplant recipient with malnutrition and recurrent infections: Implications for the SARS-CoV-2 immune response.

The clinical course and outcomes of immunocompromised patients, such as transplant recipients, with COVID-19 remain unclear. It has been postulated that a substantial portion of the disease burden seems to be mediated by the host immune activation to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Herein, we present a simultaneous heart-kidney transplant (SHKT) recipient who was hospitalized for the management of respiratory failure from volume overload complicated by failure to thrive, multiple opportunistic infections, and open non-healing wounds in the setting of worsening renal dysfunction weeks prior to the first case of SARS-CoV-2 being detected in the state of Connecticut. After his third endotracheal intubation, routine nucleic acid testing (NAT) for SARS-CoV-2, in anticipation of a planned tracheostomy, was positive. His hemodynamics, respiratory status, and ventilator requirements remained stable without any worsening for 4 weeks until he had a negative NAT test. It is possible that the immunocompromised status of our patient may have prevented significant immune activation leading up to clinically significant cytokine storm that could have resulted in acute respiratory distress syndrome and multisystem organ failure.

Vasopressin therapy in cardiac surgery.

BACKGROUND: Arginine vasopressin (AVP) is a naturally occurring peptide with diverse effects mediated through selective V1 and V2 receptors. About 10% of patients undergoing cardiopulmonary bypass develop postoperative vasodilatory shock requiring high-dose catecholamines. We sought to examine the role of AVP therapy in cardiac surgery. METHODS: A search of Medline was conducted through September 2018 using key words and medical subject headings (MeSH) relating to AVP, copeptin, and cardiac surgery. A systematic review was performed on articles as they pertained to AVP for use as a vasopressor after cardiovascular surgery complicated by vasodilatory shock. RESULTS: A relative or absolute deficiency of Arginine vasopressin is associated with vasodilatory shock after cardiopulmonary bypass. Physiologic replacement with exogenous Arginine vasopressin results in significant increases in systemic vascular resistance and mean arterial pressure with decreased requirements of catecholamines. At doses of <0.1 U/min Arginine vasopressin is safe with very few adverse effects. CONCLUSION: Post-cardiopulmonary bypass vasodilatory shock is largely due to a relative deficiency of Arginine vasopressin. Exogenous administration of low-dose Arginine vasopressin alone or in combination with traditional catecholamines is a safe and effective way to manage this type of vasodilatory shock.

Cardiopulmonary Resuscitation in Adults and Children With Mechanical Circulatory Support: A Scientific Statement From the American Heart Association.

Cardiac arrest in patients on mechanical support is a new phenomenon brought about by the increased use of this therapy in patients with end-stage heart failure. This American Heart Association scientific statement highlights the recognition and treatment of cardiovascular collapse or cardiopulmonary arrest in an adult or pediatric patient who has a ventricular assist device or total artificial heart. Specific, expert consensus recommendations are provided for the role of external chest compressions in such patients.

Systematic Review of Phosphodiesterase-5 Inhibitor Use in Right Ventricular Failure Following Left Ventricular Assist Device Implantation.

Our aim was to identify relevant literature supporting the use of phosphodiesterase-5 (PDE5) inhibitors in patients with persistent pulmonary hypertension with signs of postprocedural right ventricular (RV) dysfunction following left ventricular assist device (LVAD) implantation. We searched MEDLINE, SCOPUS, and Web of Science from inception through November 27, 2014 for citations evaluating patients with end-stage heart failure necessitating LVAD, continuous and pulsatile, who received a PDE5 inhibitor to prevent RV failure. Outcomes of interest included changes in mean pulmonary artery pressure, pulmonary vascular resistance, central venous pressure, cardiac index, and mean arterial pressure. Results are presented qualitatively. Four citations (n = 83 patients) were included. These included a single case report, two retrospective case series, and a prospective open-label study with a historical control. All four studies utilized the PDE5 inhibitor sildenafil with various doses for up to 3 months. Sildenafil routinely reduced mean pulmonary artery pressures as soon as 90 min after administration. Reductions in pulmonary vascular resistance were also seen shortly after the procedure and maintained through 12-15 weeks. While one study saw improvements in postoperative central venous pressures, another did not. Evidence supporting PDE5 inhibitor use to attenuate RV failure in patients requiring an LVAD is weak.

A Survey of Knowledge and Perspectives of Ventricular Assist Device Therapy: Evaluating the Timing of Advanced Heart Failure Referral.

BACKGROUND: While advancements in ventricular assist device (VAD) therapy have improved survival and quality of life for select patients with advanced heart failure (HF), variations in provider knowledge and opinions may ultimately serve as barriers to therapy. METHODS AND RESULTS: A 12-item survey assessing experience, knowledge, and perspectives of VAD therapy was sent to 106 practicing cardiologists at three neighboring institutions. We received 34 responses for a total response rate of 32.1%. The majority of respondents elected to refer patients with refractory disease for VAD therapy, while only 29.4% elected to refer when standard medical therapy is withdrawn due to hypotension. CONCLUSIONS: While providers are well-informed on the fundamentals of advanced therapy, identifying patients with advanced HF who may benefit from referral remains an educational challenge. An automated referral program that identifies patients with advanced HF based on validated clinical parameters could increase appropriately timed referrals to HF specialists to further improve survival and quality of life outcomes with advanced therapy.

The Association Between Baseline Left Atrial Volume Index and All-Cause Mortality in Patients with Heart Failure: A Meta-Analysis.

BACKGROUND: Enlargement of the left atrium is a marker of mortality in the general population. Left atrial volume index (LAVI) has long been proposed as a measure of prognosis in patients with heart failure (HF). The aim of this meta-analysis was to assess the utility of using baseline LAVI as an independent predictor of all-cause mortality in patients with HF. METHODS: A search of Medline and Embase bibliographic databases was performed to identify studies meeting the following inclusion criteria: 1) studies evaluating a cohort of patients with HF (both reduced and preserved ejection fraction); 2) studies conducting multivariate analysis or patient matching to determine the relationship between baseline LAVI measured by echocardiography and all-cause mortality; and 3) studies reporting data on the relationship between baseline LAVI (per difference in mL/m2) and all-cause mortality. Adjusted hazard ratios depicting the association between baseline LAVI and all-cause mortality were pooled using traditional random-effects meta-analysis. RESULTS: 1,188 publications were reviewed from which four studies were included in the present meta-analysis. We found each 10 mL/m2 increase in baseline LAVI was associated with a 22% increased adjusted hazard of all-cause mortality (95% confidence interval, 13% to 31%, I2 = 14%). CONCLUSION: Baseline LAVI is an important independent predictor of all-cause mortality in patients with heart failure and should be reported routinely in these patients undergoing echocardiography.

Reduction of Cardiac Arrests: The Experience of a Novel Service Centric Medical Emergency Team.

OBJECTIVE: To determine whether a novel, service-centric, medical emergency team (MET) model can impact cardiac arrest (CA) rates. METHODS: A retrospective pre- vs. postintervention analysis was performed on patients ≥ 18 years who had a CA between 2007 and 2012. A service centric MET model was initially implemented on the inpatient cardiology service and expanded hospital wide during 2008-2009, maturing to 10 teams in 2010. Service centric is defined as a medical or surgical service-specific MET team based on the location of the patient. RESULTS: The rate of CA (per 1,000 hospital days) in the year 2007 prior to the initiation of MET was compared to rates during program maturation (2008/2009) and after full maturation to 10 teams (2010-2012). A total of 1,140,233 hospital-care days were analyzed between 2007 and 2012, with 745 CAs recorded (0.65 events per 1,000 hospital days). The overall CA rate was higher prior to MET initiation (0.84 in 2007) compared to postinitiation (0.59 in 2008/09) and maturation to 10 teams (0.64 in 2010-12) (P < 0.003 for both pre- vs postcomparisons). No differences in CA rates were detected between either post-MET initiation time frames (P = 0.342). Similar trends in CA rates were observed in the intensive care unit (ICU) (3.96 vs 2.14 vs 2.68 per 1,000 hospital days in 2007, 2008/2009, and 2010-2012 respectively, with P < 0.001 for both pre- vs postcomparisons). CONCLUSIONS: A service-centric MET program was associated with a reduction in the rate of CAs both hospital wide and in the ICU. These observations maybe explained by the earlier intervention in care of unstable patients by an expanded group of caregivers.

Cefiderocol is Not Sequestered in an Ex Vivo Extracorporeal Membrane Oxygenation (ECMO) Circuit.

BACKGROUND AND OBJECTIVE: Extracorporeal membrane oxygenation (ECMO) is used in critically ill patients that require respiratory and/or cardiac support. Cefiderocol is a novel siderophore antibiotic that may require use in infected critically ill patients supported by ECMO. The objective of this study was to determine the loss of cefiderocol through an ex vivo adult ECMO circuit using a Quadrox-iD oxygenator. METHODS: A 3/8-inch, simulated, ex vivo closed-loop ECMO circuit was prepared with a Quadrox-iD adult oxygenator and primed with fresh whole blood. Cefiderocol was administered into the circuit to achieve a starting concentration of approximately 90 mg/L. Post-oxygenator blood samples were collected at 0, 0.25, 0.5, 1, 2, 4, 6, 12, and 24 h after the addition of the drug to determine the loss in the circuit. A glass control jar was prepared with the same blood matrix and maintained at the same temperature to determine drug degradation. The experiment was conducted in triplicate. The rate of cefiderocol loss in the ECMO circuit was compared with that in the control by one-way analysis of variance. RESULTS: At 0 h, the difference between the pre- and post-oxygenator concentrations was - 4 ± 4% (range 0 to - 7%). After 24 h, the cefiderocol percent reduction was similar between the ECMO circuit and control (50% ± 13 vs. 50% ± 9, p = 1.0). CONCLUSIONS: The degradation rate of cefiderocol did not differ significantly within the ECMO circuit and control, suggesting no loss due to sequestration or adsorption. Pharmacokinetic studies in patients supported by ECMO are warranted to determine final dosing recommendations.

Non-Lung Solid Organ Transplantation From SARS-CoV-2-Positive Donors to Uninfected Recipients.

BACKGROUND: There is a paucity of evidence on the risk of donor-recipient transmission of the SARS-CoV-2 in solid organ transplant recipients. Initial impressions suggest non-lung solid organs may be safely transplanted from SARS-CoV-2-positive donors without risk of viral transmission. METHODS: We reviewed clinical results of transplants in which SARS-CoV-2-negative recipients received non-lung solid organs from SARS-CoV-2-positive donors at a single transplant center. No prisoners were used in this study, and participants were neither coerced nor paid. The manuscript was created in compliance with the Helsinki Congress and the Declaration of Istanbul. RESULTS: Between June 2021 and January 2023, we transplanted 26 solid organs, including 13 kidneys, 8 livers, 3 hearts, and 1 simultaneous heart and kidney, from 23 SARS-CoV-2-positive donors into 25 SARS-CoV-2 negative recipients. Two of the recipients had a positive SARS-CoV-2 real-time polymerase chain reaction after transplantation, but otherwise, patients had no SARS-CoV-2-related complications, and all patients to date are alive with excellent allograft function. CONCLUSION: Transplantation of non-lung solid organs from SARS-CoV-2-positive donors into uninfected recipients can be safely performed without adverse effects from SARS-CoV-2.

Review of heart transplantation from hepatitis C-positive donors.

Significant scarcity of a donor pool exists for heart transplantation (HT) as the prevalence of patients with end-stage refractory heart failure is increasing exceptionally. With the discovery of effective direct-acting antiviral and favorable short-term outcomes following HT, the hearts from hepatitis C virus (HCV) patient are being utilized to increase the donor pool. Short-term outcomes with regards to graft function, coronary artery vasculopathy, and kidney and liver disease is comparable in HCV-negative recipients undergoing HT from HCV-positive donors compared to HCV-negative donors. A significant high incidence of donor-derived HCV transmission was observed with great success of achieving sustained viral response with the use of direct-acting antivirals. By accepting HCV-positive organs, the donor pool has expanded with younger donors, a shorter waitlist time, and a reduction in waitlist mortality. However, the long-term outcomes and impact of specific HCV genotypes remains to be seen. We reviewed the current literature on HT from HCV-positive donors.

Pharmacokinetics and Time above the MIC Exposure of Cefepime in Critically Ill Patients Receiving Extracorporeal Membrane Oxygenation (ECMO).

This study determined the pharmacokinetics of cefepime in patients requiring extracorporeal membrane oxygenation (ECMO) support to guide dosage selection. Cefepime population pharmacokinetics where characterized in Pmetrics for R for six critically ill patients receiving ECMO. Simulation was employed to determine the fT>MIC and total trough concentration of varying regimens in each patient to evaluate ability to achieve optimal pharmacodynamic exposure and thresholds for cefepime-associated neurotoxicity. Of the six participants, two required continuous veno-venous hemodiafiltration (CVVHDF) while four had a CrCL between 92-199 ml/min. All patients received 2 g q8h as a 3h infusion. A two-compartment model fitted the data best with median (range) parameter estimates as follows: clearance, 5.99 (4.10-10.29) L/h; volume of central compartment, 10.08 (2.45-15.14) L; and intercompartment transfer constants (k12), 3.58 (2.01-4.99) h-1 and k21, 1.70 (1.00-2.88) h-1. The 2g q8h (3h infusion) regimen resulted in >70% fT>MIC in all patients up to an MIC of 16 µg/mL, whereas 2g q12h (0.5h) resulted in 5/6 patients achieving 70% ƒT>MIC at 8 µg/mL but only 1/6 at 16 µg/mL. Aggressive dosing regimens resulted in trough concentrations exceeding conservative neurotoxicity thresholds. No patient demonstrated signs or symptoms of neurotoxicity during treatment. For ECMO patients with normal to augmented renal clearance similar to those presented here, or those receiving CVVHDF, these data support dosing regimens of 2g q8h (3h infusions) to empirically target MICs up to 16 µg/mL. Larger studies are needed to determine how ECMO affects cefepime pharmacokinetics.

Extracorporeal Life Support Organization Guideline for Transport and Retrieval of Adult and Pediatric Patients with ECMO Support.

DISCLAIMER: This guideline for the preparation for and undertaking of transport and retrieval of patients on extracorporeal membrane oxygenation (ECMO) is intended for educational use to build the knowledge of physicians and other health professionals in assessing the conditions and managing the treatment of patients undergoing ECLS / ECMO and describe what are believed to be useful and safe practice for extracorporeal life support (ECLS, ECMO) but these are not necessarily consensus recommendations. The aim of clinical guidelines are to help clinicians to make informed decisions about their patients. However, adherence to a guideline does not guarantee a successful outcome. Ultimately, healthcare professionals must make their own treatment decisions about care on a case-by-case basis, after consultation with their patients, using their clinical judgement, knowledge and expertise. These guidelines do not take the place of physicians' and other health professionals' judgment in diagnosing and treatment of particular patients. These guidelines are not intended to and should not be interpreted as setting a standard of care or be deemed inclusive of all proper methods of care nor exclusive of other methods of care reasonably directed to obtaining the same results. The ultimate judgment must be made by the physician and other health professionals and the patient in light of all the circumstances presented by the individual patient, and the known variability and biological behavior of the clinical condition. These guidelines reflect the data at the time the guidelines were prepared; the results of subsequent studies or other information may cause revisions to the recommendations in these guidelines to be prudent to reflect new data, but ELSO is under no obligation to provide updates. In no event will ELSO be liable for any decision made or action taken in reliance upon the information provided through these guidelines.

Post Heart Transplantation Outcomes of Patients Supported on Biventricular Mechanical Support.

With the implementation of the new heart transplant (HT) allocation system, patients requiring biventricular support systems have the highest priority, a shorter waitlist time, and a higher frequency of HT. However, the short-term and long-term outcomes of such patients are often disputed. Hence, we examined the outcomes of these patients who underwent HT before change in allocation scheme. Additionally, we compared post-HT outcomes of extracorporeal membrane oxygenation (ECMO) with other nondischargeable biventricular (BiVAD) supported patients. We identified adult ECMO or BiVAD supported HT recipients between 2000 and 2018 in the Scientific Registry of Transplant Recipients database. We compared survival with the Kaplan-Meier method. Using overlap propensity score weighting, we constructed Cox proportional hazards regression models to determine the risk-adjusted influence of BiVAD versus ECMO on survival. Of the 730 patients HT recipients; 528 (72.3%) and 202 (27.7%) were bridged with BiVAD and ECMO, respectively. For BiVAD versus ECMO patients, the 30-day, 1-year, 3-year, and 5-year mortality rates were 8.0% versus 14.4%, 16.3% versus 21.3%, 22.4% versus 25.3%, and 26.3% versus 25.7%, respectively. Risk-adjusted post-HT survival of BiVAD and ECMO patients at 30-day (HR 1.24 [95% CI, 0.68-2.27]; P = 0.4863), 1-year (HR 1.29 [95% CI, 0.80-2.09]; P = 0.3009), 3-year (HR 1.27 [95% CI, 0.83-1.94]; P = 0.2801), and 5-year (HR 1.35, 95% CI, 0.90-2.05; P = 0.1501) were similar. Around three-fourth of the ECMO or BiVAD supported patients were alive at 5-years post-HT. The short-term and long-term post-HT survivals of groups were comparable.