Cardiovascular Subphenotypes in Acute Respiratory Distress Syndrome.

OBJECTIVES: To use clustering methods on transthoracic echocardiography (TTE) findings and hemodynamic parameters to characterize circulatory failure subphenotypes and potentially elucidate underlying mechanisms in patients with acute respiratory distress syndrome (ARDS) and to describe their association with mortality compared with current definitions of right ventricular dysfunction (RVD). DESIGN: Retrospective, single-center cohort study. SETTING: University Hospital ICU, Birmingham, United Kingdom. PATIENTS: ICU patients that received TTE within 7 days of ARDS onset between April 2016 and December 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Latent class analysis (LCA) of TTE/hemodynamic parameters was performed in 801 patients, 62 years old (interquartile range, 50-72 yr old), 63% male, and 40% 90-day mortality rate. Four cardiovascular subphenotypes were identified: class 1 (43%; mostly normal left and right ventricular [LV/RV] function), class 2 (24%; mostly dilated RV with preserved systolic function), class 3 (13%, mostly dilated RV with impaired systolic function), and class 4 (21%; mostly high cardiac output, with hyperdynamic LV function). The four subphenotypes differed in their characteristics and outcomes, with 90-day mortality rates of 19%, 40%, 78%, and 59% in classes 1-4, respectively ( p < 0.0001). Following multivariable logistic regression analysis, class 3 had the highest odds ratio (OR) for mortality (OR, 6.9; 95% CI, 4.0-11.8) compared with other RVD definitions. Different three-variable models had high diagnostic accuracy in identifying each of these latent subphenotypes. CONCLUSIONS: LCA of TTE parameters identified four cardiovascular subphenotypes in ARDS that more closely aligned with circulatory failure mechanisms and mortality than current RVD definitions.

Hyperdynamic Left Ventricular Ejection Fraction in ICU Patients With Sepsis.

OBJECTIVES: To evaluate the cause and prognosis of hyperdynamic left ventricular ejection fraction in critically ill patients with sepsis. DESIGN: Retrospective, single-center cohort study. SETTING: University Hospital ICU, Birmingham, United Kingdom. PATIENTS: ICU patients who received a transthoracic echocardiogram within 7 days of sepsis between April 2016 and December 2019. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: The 90-day mortality rates of normal (55-70%), depressed (< 55%), and hyperdynamic left ventricular ejection fraction (> 70%) were compared. Multivariate logistic regression analysis was performed to determine the association of left ventricular ejection fraction phenotypes with mortality and the association of clinical variables with left ventricular ejection fraction phenotypes. One thousand fourteen patients met inclusion criteria and were 62 years old (interquartile range, 47-72), with mostly respiratory infections (n = 557; 54.9%). Ninety-day mortality was 32.1% (n = 325). Patients with hyperdynamic left ventricular ejection fraction had a higher mortality than depressed and normal left ventricular ejection fraction cohorts (58.9% [n = 103] vs 34.0% [n = 55] vs 24.7% [n = 167]; p < 0.0001, respectively). After multivariate logistic regression, hyperdynamic left ventricular ejection fraction was independently associated with mortality (odds ratio, 3.90 [2.09-7.40]), whereas depressed left ventricular ejection fraction did not (odds ratio, 0.62 [0.28-1.37]). Systemic vascular resistance was inversely associated with hyperdynamic left ventricular ejection fraction (odds ratio, 0.79 [0.58-0.95]), and age, frailty, and ischemic heart disease were associated with depressed left ventricular ejection fraction. CONCLUSIONS: Hyperdynamic left ventricular ejection fraction was associated with mortality in septic ICU patients and may reflect unmitigated vasoplegia from sepsis. Depressed left ventricular ejection fraction was not associated with mortality but was associated with cardiovascular disease.

Right Ventricular Dysfunction and Its Association With Mortality in Coronavirus Disease 2019 Acute Respiratory Distress Syndrome.

OBJECTIVES: To assess whether right ventricular dilation or systolic impairment is associated with mortality and/or disease severity in invasively ventilated patients with coronavirus disease 2019 acute respiratory distress syndrome. DESIGN: Retrospective cohort study. SETTING: Single-center U.K. ICU. PATIENTS: Patients with coronavirus disease 2019 acute respiratory distress syndrome undergoing invasive mechanical ventilation that received a transthoracic echocardiogram between March and December 2020. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: Right ventricular dilation was defined as right ventricular:left ventricular end-diastolic area greater than 0.6, right ventricular systolic impairment as fractional area change less than 35%, or tricuspid annular plane systolic excursion less than 17 mm. One hundred seventy-two patients were included, 59 years old (interquartile range, 49-67), with mostly moderate acute respiratory distress syndrome (n = 101; 59%). Ninety-day mortality was 41% (n = 70): 49% in patients with right ventricular dilation, 53% in right ventricular systolic impairment, and 72% in right ventricular dilation with systolic impairment. The right ventricular dilation with systolic impairment phenotype was independently associated with mortality (odds ratio, 3.11 [95% CI, 1.15-7.60]), but either disease state alone was not. Right ventricular fractional area change correlated with Pao2:Fio2 ratio, Paco2, chest radiograph opacification, and dynamic compliance, whereas right ventricular:left ventricle end-diastolic area correlated negatively with urine output. CONCLUSIONS: Right ventricular systolic impairment correlated with pulmonary pathophysiology, whereas right ventricular dilation correlated with renal dysfunction. Right ventricular dilation with systolic impairment was the only right ventricular phenotype that was independently associated with mortality.

The utility of arterial blood gas parameters and chest radiography in predicting appropriate intubations in burn patients with suspected inhalation injury-A retrospective cohort study.

BACKGROUND: This study evaluates the utility of arterial blood gas (ABG) parameters and chest radiography in predicting intubation need in patients with burn injuries with suspected inhalation injury. METHODS: Patients with suspected inhalation injury admitted to a single centre, Burn Intensive Care Unit, between April 4th 2016 and July 5th 2019, were included. Admission ABG parameters and chest radiograph opacification were compared with whether the patient received an appropriate intubation: defined as intubation for a duration of over 48 h. Area under the receiver operator characteristic curve was calculated (AUROC). RESULTS: Eighty-nine patients were included. The majority (84%; n = 75) were intubated, of which 81% (n = 61) received appropriate intubations. pH had an AUROC of 0.88 and a pH of <7.30 had an 80% sensitivity and specificity for detecting appropriate intubation. P/F ratio had an AUROC of 0.81 and a P/F ratio of <40 had a 70% sensitivity and specificity for appropriate intubation. Chest radiograph opacification had poor utility in this regard (AUROC = 0.69). Adding pH and P/F ratio to the ABA criteria improved their sensitivity in detecting appropriate intubations (sensitivity: ABA + pH + P/F = 0.97 vs ABA = 0.86; p = 0.013), without altering their specificity. CONCLUSIONS: In patients suspected inhalation injury, pH and P/F ratio were good predictors for appropriate intubations. Incorporating the parameters into the ABA criteria improved their clinical utility.

Pregnancy-induced haemophagocytic lymphohistiocytosis.

Haemophagocytic lymphohistiocytosis is an aggressive and life-threatening syndrome of excessive immune activation. It is associated with various aetiologies, including infections, collagen vascular diseases and malignancies. Pregnancy-induced immune dysregulation in genetically susceptible women may also play a critical role in haemophagocytic lymphohistiocytosis. Our case involves that of a 23-year-old pregnant woman who presented at 22 weeks gestation with tachycardia, swinging pyrexia, rigors and generalised myalgia. Refractory hypotension to intravenous fluids and rise in lactate level required admission to the intensive care unit for vasopressor support. Despite treatment with broad-spectrum antibiotics for presumed sepsis, she made little clinical improvement. Investigations for infection and rheumatological disease were unremarkable. A pronounced hyperferritinaemia, hypertriglyceridaemia and cytopenia raised the suspicion of haemophagocytic lymphohistiocytosis. Subsequent elevated CD25 levels helped establish the diagnosis. Treatment with corticosteroids and intravenous immunoglobulin provided a transient response in regard to temperature control and cardiovascular stability. The decision was made to treat her with anakinra, an interleukin-1 receptor antagonist. She responded well to this with a complete resolution of her symptoms and normalisation of her ferritin levels over the course of some weeks. Because of progressive slowing of foetal growth and abnormal umbilical artery Dopplers and cardiotocography, she eventually had an emergency caesarean section at 31 + 5 weeks. There were no foetal abnormalities.

A vanishing complication of haemodialysis: Dialysis disequilibrium syndrome.

Dialysis disequilibrium syndrome (DDS) is a rare syndrome characterised by neurological symptoms related to cerebral oedema. New patients who are started on haemodialysis are at the greatest risk for developing dialysis disequilibrium syndrome. Classical DDS develops during or immediately after haemodialysis. It is a generally self-limiting condition and settles with supportive management. Our case report describes DDS in a patient on chronic haemodialysis. She developed a tonic-clonic seizure shortly after completing 4 h of haemodialysis. This occurred in the context of having missed one session of dialysis, but with no new changes made to her usual dialysis regime. She was managed supportively in the intensive care unit and made a full recovery.

Haemodiafiltration as an effective treatment option for massive paracetamol overdose.

An 84-year-old woman presented to hospital with severe clinical and metabolic sequelaesequelae of a massive paracetamol overdose (concentration=822 mg/L). In spite of N-acetylcysteine therapy, she deteriorated with evidence of mitochondrial dysfunction. Although the EXtracorporeal TReatments In Poisoning group recommend adjunct haemodialysis (HD) in such a context, this was difficult to start due to haemodynamic instability. Instead, a trial of continuous venovenous haemodiafiltration (CVVHDF) was initiated in an attempt to restore normal mitochondrial function, normal pH and to actively remove the offending drug. Fortunately, plasma paracetamol levels fell exponentially over the subsequent 24-48 hours without the need to commence HD. The patient made a full recovery and was later discharged from the hospital. This case highlights that CVVHDF can be a reasonable alternative to HD for managing massive paracetamol overdoses in the context of mitochondrial dysfunction.