Mildly elevated lactate levels are associated with microcirculatory flow abnormalities and increased mortality: a microSOAP post hoc analysis.

BACKGROUND: Mildly elevated lactate levels (i.e., 1-2 mmol/L) are increasingly recognized as a prognostic finding in critically ill patients. One of several possible underlying mechanisms, microcirculatory dysfunction, can be assessed at the bedside using sublingual direct in vivo microscopy. We aimed to evaluate the association between relative hyperlactatemia, microcirculatory flow, and outcome. METHODS: This study was a predefined subanalysis of a multicenter international point prevalence study on microcirculatory flow abnormalities, the Microcirculatory Shock Occurrence in Acutely ill Patients (microSOAP). Microcirculatory flow abnormalities were assessed with sidestream dark-field imaging. Abnormal microcirculatory flow was defined as a microvascular flow index (MFI) < 2.6. MFI is a semiquantitative score ranging from 0 (no flow) to 3 (continuous flow). Associations between microcirculatory flow abnormalities, single-spot lactate measurements, and outcome were analyzed. RESULTS: In 338 of 501 patients, lactate levels were available. For this substudy, all 257 patients with lactate levels ≤ 2 mmol/L (median [IQR] 1.04 [0.80-1.40] mmol/L) were included. Crude ICU mortality increased with each lactate quartile. In a multivariable analysis, a lactate level > 1.5 mmol/L was independently associated with a MFI < 2.6 (OR 2.5, 95% CI 1.1-5.7, P = 0.027). CONCLUSIONS: In a heterogeneous ICU population, a single-spot mildly elevated lactate level (even within the reference range) was independently associated with increased mortality and microvascular flow abnormalities. In vivo microscopy of the microcirculation may be helpful in discriminating between flow- and non-flow-related causes of mildly elevated lactate levels. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01179243 . Registered on August 3, 2010.

Comparison Between Doppler-Echocardiography and Uncalibrated Pulse Contour Method for Cardiac Output Measurement: A Multicenter Observational Study.

OBJECTIVES: Echocardiography and pulse contour methods allow, respectively, noninvasive and less invasive cardiac output estimation. The aim of the present study was to compare Doppler echocardiography with the pulse contour method MostCare for cardiac output estimation in a large and nonselected critically ill population. DESIGN: A prospective multicenter observational comparison study. SETTING: The study was conducted in 15 European medicosurgical ICUs. PATIENTS: We assessed cardiac output in 400 patients in whom an echocardiographic evaluation was performed as a routine need or for cardiocirculatory assessment. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One echocardiographic cardiac output measurement was compared with the corresponding MostCare cardiac output value per patient, considering different ICU admission categories and clinical conditions. For statistical analysis, we used Bland-Altman and linear regression analyses. To assess heterogeneity in results of individual centers, Cochran Q, and the I statistics were applied. A total of 400 paired echocardiographic cardiac output and MostCare cardiac output measures were compared. MostCare cardiac output values ranged from 1.95 to 9.90 L/min, and echocardiographic cardiac output ranged from 1.82 to 9.75 L/min. A significant correlation was found between echocardiographic cardiac output and MostCare cardiac output (r = 0.85; p < 0.0001). Among the different ICUs, the mean bias between echocardiographic cardiac output and MostCare cardiac output ranged from -0.40 to 0.45 L/min, and the percentage error ranged from 13.2% to 47.2%. Overall, the mean bias was -0.03 L/min, with 95% limits of agreement of -1.54 to 1.47 L/min and a relative percentage error of 30.1%. The percentage error was 24% in the sepsis category, 26% in the trauma category, 30% in the surgical category, and 33% in the medical admission category. The final overall percentage error was 27.3% with a 95% CI of 22.2-32.4%. CONCLUSIONS: Our results suggest that MostCare could be an alternative to echocardiography to assess cardiac output in ICU patients with a large spectrum of clinical conditions.

International study on microcirculatory shock occurrence in acutely ill patients.

OBJECTIVES: Microcirculatory alterations are associated with adverse outcome in subsets of critically ill patients. The prevalence and significance of microcirculatory alterations in the general ICU population are unknown. We studied the prevalence of microcirculatory alterations in a heterogeneous ICU population and its predictive value in an integrative model of macro- and microcirculatory variables. DESIGN: Multicenter observational point prevalence study. SETTING: The Microcirculatory Shock Occurrence in Acutely ill Patients study was conducted in 36 ICUs worldwide. PATIENTS: A heterogeneous ICU population consisting of 501 patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Demographic, hemodynamic, and laboratory data were collected in all ICU patients who were 18 years old or older. Sublingual Sidestream Dark Field imaging was performed to determine the prevalence of an abnormal capillary microvascular flow index (< 2.6) and its additional value in predicting hospital mortality. In 501 patients with a median Acute Physiology and Chronic Health Evaluation II score of 15 (10-21), a Sequential Organ Failure Assessment score of 5 (2-8), and a hospital mortality of 28.4%, 17% exhibited an abnormal capillary microvascular flow index. Tachycardia (heart rate > 90 beats/min) (odds ratio, 2.71; 95% CI, 1.67-4.39; p < 0.001), mean arterial pressure (odds ratio, 0.979; 95% CI, 0.963-0.996; p = 0.013), vasopressor use (odds ratio, 1.84; 95% CI, 1.11-3.07; p = 0.019), and lactate level more than 1.5 mEq/L (odds ratio, 2.15; 95% CI, 1.28-3.62; p = 0.004) were independent risk factors for hospital mortality, but not abnormal microvascular flow index. In reference to microvascular flow index, a significant interaction was observed with tachycardia. In patients with tachycardia, the presence of an abnormal microvascular flow index was an independent, additive predictor for in-hospital mortality (odds ratio, 3.24; 95% CI, 1.30-8.06; p = 0.011). This was not true for nontachycardic patients nor for the total group of patients. CONCLUSIONS: In a heterogeneous ICU population, an abnormal microvascular flow index was present in 17% of patients. This was not associated with mortality. However, in patients with tachycardia, an abnormal microvascular flow index was independently associated with an increased risk of hospital death.

Lung ultrasound for the early diagnosis of COVID-19 pneumonia: an international multicenter study.

PURPOSE: To analyze the application of a lung ultrasound (LUS)-based diagnostic approach to patients suspected of COVID-19, combining the LUS likelihood of COVID-19 pneumonia with patient's symptoms and clinical history. METHODS: This is an international multicenter observational study in 20 US and European hospitals. Patients suspected of COVID-19 were tested with reverse transcription-polymerase chain reaction (RT-PCR) swab test and had an LUS examination. We identified three clinical phenotypes based on pre-existing chronic diseases (mixed phenotype), and on the presence (severe phenotype) or absence (mild phenotype) of signs and/or symptoms of respiratory failure at presentation. We defined the LUS likelihood of COVID-19 pneumonia according to four different patterns: high (HighLUS), intermediate (IntLUS), alternative (AltLUS), and low (LowLUS) probability. The combination of patterns and phenotypes with RT-PCR results was described and analyzed. RESULTS: We studied 1462 patients, classified in mild (n = 400), severe (n = 727), and mixed (n = 335) phenotypes. HighLUS and IntLUS showed an overall sensitivity of 90.2% (95% CI 88.23-91.97%) in identifying patients with positive RT-PCR, with higher values in the mixed (94.7%) and severe phenotype (97.1%), and even higher in those patients with objective respiratory failure (99.3%). The HighLUS showed a specificity of 88.8% (CI 85.55-91.65%) that was higher in the mild phenotype (94.4%; CI 90.0-97.0%). At multivariate analysis, the HighLUS was a strong independent predictor of RT-PCR positivity (odds ratio 4.2, confidence interval 2.6-6.7, p < 0.0001). CONCLUSION: Combining LUS patterns of probability with clinical phenotypes at presentation can rapidly identify those patients with or without COVID-19 pneumonia at bedside. This approach could support and expedite patients' management during a pandemic surge.

The role of side stream dark field microvasculature imaging in a rare case of vancomycin-resistant enterococcal endocarditis complicated by heparin-induced thrombocytopenia.

Sidestream dark field (SDF) imaging allows direct visualization of microvascular architecture and function. We examine the role of an SDF imaging device in visualizing the sub-lingual microvasculature as a surrogate for splanchnic microperfusion. We demonstrate good correlation between current monitoring techniques and the SDF imaging device in a rare case of vancomycin-resistant enterococcal (VRE) sepsis along with heparin-induced thrombocytopenia (HIT). To the best of our knowledge, VRE endocarditis with concurrent HIT has not been described in literature. The role of SDF imaging may predict the earlier need for escalation of care, improving morbidity and mortality.

Ventricular mass: a clinical and surgical conundrum.

Cardiac tumours are rare in occurrence. The authors report a patient who presented with a history of recurrent transient ischemic attacks and cerebrovascular accidents. During rehabilitation he was incidentally diagnosed with a large left ventricular mass which was excised successfully with good clinical outcome. On histopathology it was a papillary fibroelastoma.