A real life evaluation of non invasive ventilation in acute cardiogenic pulmonary edema: a multicenter, perspective, observational study for the ACPE SIMEU study group.

BACKGROUND: During the past three decades conflicting evidences have been published on the use of non-invasive ventilation (NIV) in patients with acute cardiogenic pulmonary edema (ACPE). The aim of this study is to describe the management of acute respiratory failure (ARF) due to ACPE in twelve Italian emergency departments (EDs). We evaluated prevalence, characteristics and outcomes of ACPE patients treated with oxygen therapy, continuous positive airway pressure (CPAP) or Bi-level positive airway pressure (BiPAP) on admission to the EDs. METHODS: In this multicenter, prospective, observational study, consecutive adult patients with ACPE were enrolled in 12 EDs in Italy from May 2009 to December 2013. Three study groups were identified according to the initial respiratory treatment: patients receiving oxygen therapy, those treated with CPAP and those treated with BiPAP. Treatment failure was evaluated as study outcome. RESULTS: We enrolled 1293 patients with acute cardiogenic pulmonary edema. 273 (21%) began with oxygen, 788 (61%) with CPAP and 232 (18%) with BiPAP. One out of four patient who began with oxygen was subsequently switched to NIV and initial treatment with oxygen therapy had an odds ratio for treatment failure of 3.65 (95% CI: 2.55-5.23, p < 0.001). CONCLUSIONS: NIV seems to be the first choice for treatment of ARF due to ACPE, showing high clinical effectiveness and representing a rescue option for patients not improving with conventional oxygen therapy.

A Diagnostic Model to Predict SARS-CoV-2 Positivity in Emergency Department Using Routine Admission Hematological Parameters.

Early detection of SARS-CoV-2 in the emergency department (ED) is a crucial necessity, especially in settings of overcrowding: establishing a pre-diagnostic test probability of infection would help to triage patients and reduce diagnostic errors, and it could be useful in resource-limited countries. Here, we established and validated a clinical predictor of infection based on routine admission hematological parameters. The diagnostic model was developed by comparing 85 consecutive patients with symptomatic COVID-19 confirmed by RT-PCR with 85 symptomatic, SARS-CoV-2-negative controls. Abnormal hematological parameters significantly (p < 0.05) associated with SARS-CoV-2 infection were used to derive a "cumulative score" between 0 and 16. The model was validated in an independent cohort of 170 SARS-CoV-2-positive patients. Several routine hematology parameters were significantly (p < 0.05) associated with SARS-CoV-2 infection. A "cumulative score" score ≥7 discriminated COVID-19-postive patients from controls with a sensitivity of 94% and specificity of 100% (p < 0.001). The high sensitivity of the predictive model was confirmed in the prospective validation set, and the cumulative score (i) predicted SARS-CoV-2 positivity even when the first oro-nasopharyngeal swab RT-PCR result was reported as a false negative in both cohorts and (ii) resulted to be independent from disease severity. The cumulative score based on routine blood parameters can be used to predict an early and accurate diagnosis of SARS-CoV-2 infection in symptomatic patients, thereby facilitating triage and optimizing early management and isolation from the COVID-19 free population, particularly useful in overcrowding situations and in resource-poor settings.

Time-weighted lactate as a predictor of adverse outcome in acute heart failure.

AIMS: The role of dynamic changes in lactate concentrations on prognosis in acute heart failure has been poorly investigated. The aim of this study was to explore the predictive value of 24 h time-weighted lactate (LACTW ) in patients with acute heart failure. METHODS AND RESULTS: Ninety-six consecutive acute heart failure patients presenting to the Emergency Department of San Paolo Hospital, Naples, Italy, were prospectively enrolled. Arterial blood lactate was measured at admission and during the following 24 h at random time intervals. LACTW was obtained by the sum of the average lactate values among consecutive time points multiplied by the intervals between consecutive time points and dividing the sum by the total time (24 h). The outcome was a composite of need of admission to the intensive care unit, hospitalization duration >7 days, or intra-hospital death. Admission lactate, maximum measured lactate, and LACTW were collected. Univariate and multivariate Cox regression analysis was applied to determine the hazard ratio (HR) of developing the outcome. Forty-three patients experienced the pre-specified outcome. In sex-adjusted and age-adjusted multivariable analysis, LACTW predicted the outcome occurrence (HR: 1.51, 95% confidence interval: 1.24, 1.84, P < 0.001). Risk stratification analysis based on LACTW tertiles demonstrated a gradual increase in risk of developing the outcome (HR: 17.32, 95% confidence interval: 2.30, 130.23, P = 0.006) for the highest LACTW tertile. CONCLUSIONS: In acute heart failure patients, 24 h LACTW had a significant independent predictive value for adverse intra-hospital outcome. LACTW could be a useful index at identifying high-risk patients who may require a more aggressive treatment during hospitalization.

Dyselectrolytemias and arrhythmias.

Critical care patients are submitted to multiple derangements of vital parameters. Even in patients with a normally performing heart, its electrical activity can be strongly influenced by dyselectrolytemias, acid-base imbalance and aggressive drug therapy. In this paper, the basic principles of the electrophysiologic properties of the heart are reviewed, and the impact of dyselectrolytemias on heart excitability are underlined. Some clinically relevant aspects are described in greater depth, with respect to life-threatening arrhythmias.

Lactate Arterial-Central Venous Gradient among COVID-19 Patients in ICU: A Potential Tool in the Clinical Practice.

OBJECTIVE: In physiological conditions, arterial blood lactate concentration is equal to or lower than central venous blood lactate concentration. A reversal in this rate (i.e., higher lactate concentration in central venous blood), which could reflect a derangement in the mitochondrial metabolism of lung cells induced by inflammation, has been previously reported in patients with ARDS but has been never explored in COVID-19 patients. The aim of this study was to explore if the COVID-19-induced lung cell damage was mirrored by an arterial lactatemia higher than the central venous one; then if the administration of anti-inflammatory therapy (i.e., canakinumab 300 mg subcutaneous) could normalize such abnormal lactate a-cv difference. METHODS: A prospective cohort study was conducted, started on March 25, 2020, for a duration of 10 days, enrolling 21 patients affected by severe COVID-19 pneumonia undergoing mechanical ventilation consecutively admitted to the ICU of the Rimini Hospital, Italy. Arterial and central venous blood samples were contemporarily collected to calculate the difference between arterial and central venous lactate (Delta a-cv lactate) concentrations within 24 h from tracheal intubation (T 0) and 24 hours after canakinumab administration (T 1). RESULTS: At T 0, 19 of 21 (90.5%) patients showed a pathologic Delta a-cv lactate (median 0.15 mmol/L; IQR 0.07-0.25). In the 13 patients undergoing canakinumab administration, at T 1, Delta a-cv lactate decreased in 92.3% of cases, the decrease being statistically significant (T 0: median 0.24, IQR 0.09-0.31 mmol/L; T 1: median -0.01, IQR -0.08-0.04 mmol/L; p=0.002). CONCLUSION: A reversed Delta a-cv lactate might be interpreted as one of the effects of COVID-19-related cytokine storm, which could reflect a derangement in the mitochondrial metabolism of lung cells induced by severe inflammation or other uncoupling mediators. In addition, Delta a-cv lactate decrease might also reflect the anti-inflammatory activity of canakinumab. Our preliminary findings need to be confirmed by larger outcome studies.

Hyperkalemia induced failure of pacemaker capture and sensing.

Hyperkalemia may cause cardiac pacemaker (PMK) malfunctioning due to a reduction of the electronegativity of the resting myocardial potential. Both sensing and capture mechanisms could be temporarily affected, with possible life-threatening effects. Calcium chloride may counteract almost immediately such a dangerous effect of hyperkalemia, restoring the normal pacemaker function. We describe the case of a 75-year-old woman, observed in the Emergency Department for extreme weakness, very large QRS complexes, and a pacemaker type II exit block, associated with sensing failure and "spike-on-T" phenomenon. She was managed with immediate i.v. calcium chloride, followed by insulin/glucose and sodium bicarbonate infusions; the ECG recordings show an almost immediate correction of the PMK malfunctioning and serial improvement of the intraventricular conduction. This case supports the feasibility and effectiveness of i.v. calcium administration, as expected on the basis of electrophysiological ionized calcium effect on the threshold potential.

[Central venous blood gas analysis]. / Emogasanalisi dal catetere venoso centrale: una finestra sulla perfusione.

The hemodialysis might interfere with patients hemodynamic, as the technique allows a sophisticated game with extra and intravascular fluids. As the cardiocirculatory response could sometimes be unpredictable, it is interesting to collect valuable information by reaching a deep understanding of the tissue metabolism which is mirrored by the blood gas analysis of variations in arterial and central venous blood samples. Particularly interesting are the time course variations of the central venous hemoglobin saturation (ScvO2), which are directly related to the patient with O2-demand as well as to the O2-Delivery (DO2). The ScvO2 is determined by four parameters (cardiac output, Hb concentration, arterial Hb saturation and O2 consumption): If the fluids subtraction during dialysis was about to determine an occult hypoperfusion, the ScvO2 reduction would be a timely warning sign to be considered. Moreover, while the normal veno-arterial PCO2 difference is 2-4 mmHg, whenever a mismatch between O2-demand and DO2arise, a larger v-aPCO2 difference should be observed.

Base excess, strong ion difference, and expected compensations: as simple as it is.

The main purpose of this article is to provide some practical insights into acid-base disorders interpretation, comparing the three most widespread diagnostic approaches. After a brief summary of the history of blood gas analysis and the shift from a purely chemical approach to more clinically useful applications, the pros and cons of the different methodologies are compared and discussed. Reviewing the most important publications in the field, the authors attempt to show that each diagnostic strategy is acceptable, although the one based on base-excess calculation perhaps seems too 'rough' to understand the mixed disorders, whereas the Stewart approach is attractive from a chemical point of view, but unsuitable for the emergency physician because of the cumbersome calculations needed. Finally, the anion gap and 'expected compensation' approach seems to be more comprehensive and feasible at the bedside.

Two-hour lactate clearance predicts negative outcome in patients with cardiorespiratory insufficiency.

Objective. To evaluate 2-hour lactate clearance as a prognostic marker in acute cardiorespiratory insufficiency. Design. Prospective observational study. Setting. Emergency Department (ED) and 16-bed medical High Dependency Unit (HDU). Methods and Main Results. 95 consecutive admissions from the ED for acute cardiorespiratory insufficiency were prospectively enrolled. Arterial lactate concentration was assessed at ED arrival and 1, 2, 6, and 24 hours later. The predictive value of 2-hour lactate clearance was evaluated for negative outcomes defined as hospital mortality or need for endotracheal intubation versus positive outcomes defined as discharge or transfer to a general medical ward. Logistic regression and ROC curves found 2-hour lactate clearance >15% was a strong predictor of negative outcome (P < .0001) with a sensitivity of 86% (95%CI = 67%-95%) and a specificity of 91% (95%CI = 82%-96%), Positive predictive value was 80% (95%CI = 61%-92%), and negative predictive value was 92% (95%CI = 84%-98%). Conclusions. Systematic monitoring of lactate clearance at 2 hours can be used in to identify patients at high risk of negative outcome and perhaps to tailor more aggressive therapy. Equally important is that a 2-hour lactate clearance >15% is highly predictive of positive outcome and may reassure clinicians that the therapeutic approach is appropriate.

Inferior vena cava collapsibility to guide fluid removal in slow continuous ultrafiltration: a pilot study.

OBJECTIVE: To investigate whether ultrasound determination of the inferior vena cava diameter (IVCD) and its collapsibility index (IVCCI) could be used to optimize the fluid removal rate while avoiding hypotension during slow continuous ultrafiltration (SCUF). METHODS: Twenty-four consecutive patients [13 men and 11 women, mean age 72 +/- 5 years; New York Heart Association (NYHA) functional classes III-IV] with acute decompensated heart failure (ADHF) and diuretic resistance were admitted to our 16-bed medical ICU. Blood pressure (BP), heart rate (HR), respiratory rate (RR), blood samples for hematocrit, creatinine, sodium, potassium, and arterial BGA plus lactate were obtained at baseline and than every 2 h from the beginning of SCUF. IVCD, assessed by M-mode subcostal echocardiography during spontaneous breathing, was evaluated before SCUF, at 12 h, and just after the cessation of the procedure. The IVCCI was calculated as follows: [(IVCD(max) - IVCD(min))/IVCD(max)] x 100. RESULTS: Mean UF time was 20.3 +/- 4.6 h with a mean volume of 287.6 +/- 96.2 ml h(-1) and a total ultrafiltrate production of 5,780.8 +/- 1,994.6 ml. No significant difference in MAP, HR, RR, and IVCD before and after UF was found. IVCCI increased significantly after UF (P < 0.001). Hypotension was observed only in those patients (2/24) who reached an IVCCI >30%. In all the other patients, a significant increase in IVCCI was obtained without any hemodynamic instability. CONCLUSION: IVC ultrasound is a rapid, simple, and non-invasive means for bedside monitoring of intravascular volume during SCUF and may guide fluid removal velocity.