Association of biofilm formation, antimicrobial resistance, clinical characteristics, and clinical outcomes among Acinetobacter baumannii isolates from patients with ventilator-associated pneumonia.

INTRODUCTION: Biofilm formation is an important virulence factor of Acinetobacter baumannii. Here, we examined the biofilm formation of archived A. baumannii causing ventilator-associated pneumonia (VAP). METHODS: Eighteen and twenty isolates of A. baumannii causing bacteremic pneumonia and non-bacteremic pneumonia were included, respectively. Antimicrobial susceptibility testing was performed by broth microdilution method, while biofilm formation was evaluated by microtiter dish biofilm formation assay. RESULTS: All 38 isolates were still susceptible to colistin and tigecycline, whereas almost all isolates were non-susceptible (intermediate to resistant) to several antimicrobial agents, especially ceftriaxone and cefotaxime. Approximately, 44% of bacteremic isolates and 50% of non-bacteremic isolates were classified as carbapenem-resistant A. baumannii (CRAB). Biofilm formation was detected in 42% of the studied isolates. Bacteremia among the patients infected with biofilm-producing isolates was significantly higher than in those infected with non-biofilm-producing isolates. The antimicrobial susceptibilities of A. baumannii with biofilm formation were lower than those without biofilm formation, but the differences did not have statistical significance. The patients infected with non-biofilm-producing isolates had good clinical and non-clinical outcomes than those infected with biofilm-producing isolates. The survival rate of patients diagnosed with VAP due to biofilm-producing A. baumannii was lower than in those patients diagnosed with VAP due to non-biofilm-producing isolates. CONCLUSION: Biofilm formation of A. baumannii causing VAP was associated with antimicrobial resistance and bacteremia as well as unfavorable clinical outcomes.

Interchangeability of transthoracic and transesophageal echocardiographic right heart measurements in the perioperative setting and correlation with hemodynamic parameters.

Reduction of right ventricular (RV) function after cardiac surgery has been shown to impact outcomes. Conventional indices for right ventricular dysfunction are validated using transthoracic echocardiogram (TTE) which has limited use compared to transesophageal echocardiogram (TEE) in the perioperative settings. The aim of this study was to assess the agreement of RV systolic function assessment with TEE compared to TTE and assess the association of echocardiographic parameter with hemodynamic indices of RV dysfunction. This was a single center prospective observational study in an academic institution. Fifty adult patients undergoing elective cardiac surgery were included. TTE, TEE and stroke volume measurements pre-cardiopulmonary bypass (CPB) and post-CPB were performed. The variables of interest were anatomical M-mode tricuspid annular plane systolic excursion (AMM-TAPSE), fractional area change (FAC), tricuspid annular velocity (S') and myocardial performance index (MPI). FAC and AMM-TAPSE measured at the mid-esophageal 4 chamber view had substantial agreement with the TTE acquired parameters (Lin's concordance correlation coefficient (CCC) = 0.76, 95%CI 0.59-0.86 and CCC = 0.85, 95%CI 0.76-0.91). S' was significantly underestimated by TEE (CCC = 0.07, 95%CI 0.04-0.19) and MPI showed moderate agreement (CCC = 0.45 95%CI 0.19-0.65). Despite the significant changes in echocardiographic parameters, there were no corresponding changes in stroke volume (SV) or pulmonary artery pulsatility index at the post-CPB period. TEE acquired FAC and AMM-TAPSE had substantial agreement with pre-operative TTE values and no significant differences between the pre-CPB and post-CPB period. Systolic RV echocardiographic parameters decreased post-CPB but this was not accompanied by significant hemodynamic changes.

Right Ventricular Limitation: A Tale of Two Elastances.

Right ventricular (RV) dysfunction is a commonly considered cause of low cardiac output in critically ill patients. Its management can be difficult and requires an understanding of how the RV limits cardiac output. We explain that RV stroke output is caught between the passive elastance of the RV walls during diastolic filling and the active elastance produced by the RV in systole. These two elastances limit RV filling and stroke volume and consequently limit left ventricular stroke volume. We emphasize the use of the term "RV limitation" and argue that limitation of RV filling is the primary pathophysiological process by which the RV causes hemodynamic instability. Importantly, RV limitation can be present even when RV function is normal. We use the term "RV dysfunction" to indicate that RV end-systolic elastance is depressed or diastolic elastance is increased. When RV dysfunction is present, RV limitation occurs at lowerpulmonary valve opening pressures and lower stroke volume, but stroke volume and cardiac output still can be maintained until RV filling is limited. We use the term "RV failure" to indicate the condition in which RV output is insufficient for tissue needs. We discuss the physiological underpinnings of these terms and implications for clinical management.

Clinical and Histopathologic Features of Myocarditis in Multisystem Inflammatory Syndrome (Adult)-Associated COVID-19.

BACKGROUND: Multisystem inflammatory syndrome (MIS) associated with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is a life-threatening condition first described in children (MIS-C). It is characterized by a hyperinflammatory state that involves the cardiovascular, gastrointestinal, dermatologic, and neurologic systems without severe respiratory system involvement. Myocarditis is one of the cardiovascular presentations of MIS that might be complicated with cardiogenic shock. There are few case reports describing SARS-CoV-2-related MIS in adults (MIS-A). CASE SUMMARY: Three cases of healthy young adults diagnosed with severe acute respiratory syndrome-CoV-2 related (MIS-A). The main presentation was cardiogenic shock secondary to histologically proven myocarditis, which resolved rapidly after initiation of medical therapy including anti-inflammatory and immunosuppressive drugs. All the cases, however, required mechanical circulatory support (MCS) as a bridge to recovery. CONCLUSIONS: It appears reasonable to treat the patient with fulminant myocarditis in SARS-CoV-2-associated MIS-A with high-dose corticosteroid "pulse" therapy in order to suppress the inflammatory response and MCS to correct initial metabolic derangement and reestablish/maintain vital organ perfusion. Addition of IV immunoglobulin and other immunomodulators should be assessed in a case-by-case basis especially considering the associated cost resource allocation.

Right Ventricular Loading by Lung Inflation during Controlled Mechanical Ventilation.

Rationale: The inspiratory rise in transpulmonary pressure during mechanical ventilation increases right ventricular (RV) afterload. One mechanism is that when Palv exceeds left atrial pressure, West zone 1 or 2 (non-zone 3) conditions develop, and Palv becomes the downstream pressure opposing RV ejection. The Vt at which this impact on the right ventricle becomes hemodynamically evident is not well established. Objectives: To determine the magnitude of RV afterload and prevalence of significant non-zone 3 conditions during inspiration across the range of Vt currently prescribed in clinical practice. Methods: In postoperative passively ventilated cardiac surgery patients, we measured right atrial, right ventricle, pulmonary artery, pulmonary artery occlusion pressure, plateau pressure, and esophageal pressure during short periods of controlled ventilation, with Vt increments ranging between 2 and 12 ml/kg predicted body weight (PBW). The inspiratory increase in RV afterload was evaluated hemodynamically and echocardiographically. The prevalence of non-zone 3 conditions was determined using two definitions based on changes in esophageal pressure, pulmonary artery occlusion pressure, and plateau pressure. Measurements and Main Results: Fifty-one patients were studied. There was a linear relationship between Vt, driving pressure, transpulmonary pressure, and the inspiratory increase in the RV isovolumetric contraction pressure. Echocardiographically, increasing Vt was associated with a greater inspiratory increase in markers of afterload and a decrease in stroke volume. Non-zone 3 conditions were present in >50% of subjects at a Vt ⩾ 6 ml/kg PBW. Conclusions: In the Vt range currently prescribed, RV afterload increases with increasing Vt. A mechanical ventilation strategy that limits Vt and driving pressure is cardioprotective.

Allogeneic Hematopoietic Stem Cell Transplant Infusion During Venovenous Extracorporeal Membrane Oxygenation Support.

Management of hematopoietic stem cell transplant complicated by respiratory failure has been facilitated by the use of extracorporeal membrane oxygenation as a bridge to curative chemotherapeutic options. This is the first report of hematopoietic stem cell transplantation on extracorporeal membrane oxygenation in the adult population. CASE SUMMARY: A 28-year-old woman diagnosed with idiopathic aplastic anemia complicated by acute respiratory distress syndrome secondary to pneumonia required venovenous extracorporeal membrane oxygenation to supplement oxygenation and ventilation. She received hematopoietic stem cell transplantation while she was on extracorporeal membrane oxygenation support. MAIN RESULTS AND CONCLUSION: Delivery of the stem cell through extracorporeal membrane oxygenation circuit was successful in the described patient. There was no sequestered stem cell in extracorporeal membrane oxygenation circuit, and she was found to have 90% donor chimerism suggesting successful engraftment. This report showed that infusion of stem cell through extracorporeal membrane oxygenation circuit is safe and feasible, and our results suggest that successful engraftment is possible.

Awake Venovenous Extracorporeal Membrane Oxygenation for Coronavirus Disease 2019 Acute Respiratory Failure.

Implantation of venovenous extracorporeal membrane oxygenation as an alternative to invasive mechanical ventilation, an "awake approach," may facilitate a lung- and diaphragm-protective ventilatory strategies without the associated harms of endotracheal intubation, positive pressure ventilation, and continuous sedation. This report presents the characteristics and outcomes of the patients treated with the awake venovenous extracorporeal membrane oxygenation approach. DESIGN: Retrospective case series. SETTING: Monocenter study. PATIENTS: Severe acute respiratory syndrome coronavirus 2 patients with acute respiratory failure treated with venovenous extracorporeal membrane oxygenation instead of invasive mechanical ventilation from March 2020 to March 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Physiologic and laboratory data were collected at admission to the ICU, prior to and after venovenous extracorporeal membrane oxygenation implantation, and at decannulation. Seven patients were treated with venovenous extracorporeal membrane oxygenation instead of invasive mechanical ventilation due to hypoxemia with a median Pao2/Fio2 ratio at implantation of 76 (interquartile range, 59-92). Four patients in the awake group subsequently required invasive mechanical ventilation, and only one patient (14.3%) died. There were no significant complications attributed venovenous extracorporeal membrane oxygenation. CONCLUSIONS: This report demonstrates that in a selected group of patients, an "awake" venovenous extracorporeal membrane oxygenation approach is feasible and may result in favorable outcomes.

Prolonged Extracorporeal Membrane Oxygenation Support In a Patient with Drug Reaction with Eosinophilia and Systemic Symptoms Syndrome-associated Fulminant Myocarditis - A Case Report and Literature Review.

Introduction: Myocarditis is a rare presentation of drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome, traditionally associated with poor clinical outcomes. Prompt recognition and treatment are crucial. Case presentation: A 16-year-old patient presented with acute chest pain, hypotension, and pulmonary oedema 2 months after being diagnosed with trimethoprim/sulfamethoxazole-induced DRESS syndrome. Typical DRESS features were absent at onset of these symptoms. Echocardiography demonstrated biventricular systolic dysfunction, and electrocardiography (ECG) showed complete right bundle branch block and diffuse ST-segment elevation. The patient was admitted for high-dose inotropic support; however, his condition deteriorated. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and intra-aortic balloon pump were initiated on the third day of admission. Endomyocardial biopsy suggested the diagnosis of DRESS-associated myocarditis and a high-dose corticosteroid was commenced. While he was ECMO-dependent, the patient suffered multiple episodes of ventricular tachycardia on a background of cardioversion-resistant accelerated idioventricular rhythm. After 24 days of ECMO support, the ventricular function improved, and ECG reverted to sinus rhythm. His recovery allowed corticosteroid discontinuation 15 months after hospital discharge. Conclusion: Typical DRESS syndrome features may not accompany the onset of DRESS-associated myocarditis. Mechanical circulatory support and adequate immunosuppression could save patients with malignant arrhythmias and delayed myocardial recovery.

Characteristics and Outcomes of Severe ARDS Patients Receiving ECMO in Southern Thailand.

Extracorporeal membrane oxygenation (ECMO) is a treatment option considered for acute respiratory distress syndrome (ARDS) patients who are refractory to conventional treatments. However, treatment with ECMO has not shown significant reduction of mortality which may be due to inappropriate selection criteria. Thus, we aim to evaluate the treatment outcomes of patients treated with ECMO in our center and determine an optimal cutoff level of the Respiratory ECMO Survival Prediction (RESP) score for case selection. This was a retrospective case-control study conducted at Songklanagarind Hospital, Thailand, from January 2014 to August 2018. ECMO patients were randomly matched to a control group of patients with severe ARDS within the same time period. There were 19 cases diagnosed with ARDS and treated with ECMO and 57 controls with ARDS. The patients in both groups had an average APACHE II score of 30.2 (SD = 4.7) and mainly had bacterial pneumonia. The in-hospital mortality was not significantly different between the cases and controls (68.4% vs 63.2%, respectively); however, the ECMO cases had a significantly longer length of intensive care unit stay and cost of hospitalization. Active malignancy, male gender, PaO2/FiO2 ratio, and hypotension needing vasopressors were the risk factors for mortality. The RESP score did not discriminate between the survivors and nonsurvivors. Thus, more patient is needed to construct a better selection criterion.

Characteristics of Creatine Kinase Elevation in Trauma Patients and Predictors of Acute Kidney Injury.

INTRODUCTION: Rhabdomyolysis in general trauma patients is a cause of acute kidney injury. However, there are limited data on prevalence, risk factors and the dynamics of creatine kinase (CK) as a surrogate marker for rhabdomyolysis. AIM: This study aimed to examine the characteristics of CK elevation in general trauma patients and identify the risk factors of acute kidney injury (AKI). METHOD: A retrospective study of trauma patients at Songklanagarind Hospital from January 2009 to August 2014 using CK, clinical characteristics and trauma severity as predictors and AKI as defined by the Acute Kidney Injury Network, 2005 criteria as the outcomes. RESULTS: Of the 372 patients included in the study, the prevalence of rhabdomyolysis was 40.3%, the mean injury severity score (ISS) was 19.5 and 7% had AKI. The CK level peaked at 40 hours after admission with a rate change of 50.98 U/L/h. An initial mean arterial pressure < 65 mmHg, ISS ≥ 25 and CK elevation > 1,000 U/L/h were independently associated with AKI. CONCLUSION: Traumatic rhabdomyolysis resulting in AKI occurs in patients with a high peak CK with an increasing rate of change and a high ISS. These parameters could identify patients who needed close monitoring of CK and renal function.