Dynamic arterial elastance measured with pressure recording analytical method, and mean arterial pressure responsiveness in hypotensive preload dependent patients undergoing cardiac surgery: A prospective cohort study.

BACKGROUND: Organ perfusion is a factor of cardiac output and perfusion pressure. Recent evidence shows that dynamic arterial elastance is a reliable index of the interaction between the left ventricle and the arterial system and, in turn, of left ventricular mechanical efficiency. A practical approach to the assessment of dynamic arterial elastance at the bedside is the ratio between pulse pressure variation and stroke volume variation, which might predict the effect of a fluid challenge on the arterial pressure in patients undergoing cardiac surgery. OBJECTIVE: To evaluate the ability of dynamic arterial elastance, measured by the pressure recording analytical method (PRAM), to predict the response of mean arterial pressure (MAP) to a fluid challenge. DESIGN: Prospective observational study. SETTING: Cardiac surgery patients in a university hospital. PATIENTS: Preload-dependent (pulse pressure variation ≥13%), hypotensive (MAP ≤65 mmHg) patients, without right ventricular dysfunction, at the end of cardiac surgery. INTERVENTIONS: A 250 ml fluid challenge infused over 3 min. MAIN OUTCOME MEASURES: A receiver-operating characteristic curve was generated to test the ability of the baseline (before fluid challenge) dynamic arterial elastance (primary endpoint) and all other haemodynamic variables (secondary endpoint) to predict MAP responsiveness (≥10% increase in MAP) after a fluid challenge. RESULTS: Of 270 patients undergoing cardiac surgery, 97 (35.9%) were preload-dependent, hypotensive and received a fluid challenge. Of these 97 patients, 50 (51%) were MAP responders (≥10% increase in MAP) and 47 (48%) were MAP nonresponders (<10% increase in MAP). Baseline dynamic arterial elastance (mean ±â€ŠSD) had an area under the curve of 0.64 ±â€Š0.06 [95% confidence interval (CI), 0.53 to 0.73; P = 0.017]. A dynamic arterial elastance at least 1.07 with a grey zone ranging between 0.9 and 1.5 had 86% sensitivity (95% CI, 73 to 94) and 45% specificity (95% CI, 30 to 60) in predicting MAP increase. CONCLUSION: In a hypotensive preload-dependent cardiac surgery cohort without right ventricular dysfunction, dynamic arterial elastance measured by PRAM can predict pressure response for values greater than 1.5 or less than 0.9.

A Systematic Review and International Web-Based Survey of Randomized Controlled Trials in the Perioperative and Critical Care Setting: Interventions Increasing Mortality.

OBJECTIVE: Reducing mortality is a key target in critical care and perioperative medicine. The authors aimed to identify all nonsurgical interventions (drugs, techniques, strategies) shown by randomized trials to increase mortality in these clinical settings. DESIGN: A systematic review of the literature followed by a consensus-based voting process. SETTING: A web-based international consensus conference. PARTICIPANTS: Two hundred fifty-one physicians from 46 countries. INTERVENTIONS: The authors performed a systematic literature search and identified all randomized controlled trials (RCTs) showing a significant increase in unadjusted landmark mortality among surgical or critically ill patients. The authors reviewed such studies during a meeting by a core group of experts. Studies selected after such review advanced to web-based voting by clinicians in relation to agreement, clinical practice, and willingness to include each intervention in international guidelines. MEASUREMENTS AND MAIN RESULTS: The authors selected 12 RCTs dealing with 12 interventions increasing mortality: diaspirin-crosslinked hemoglobin (92% of agreement among web voters), overfeeding, nitric oxide synthase inhibitor in septic shock, human growth hormone, thyroxin in acute kidney injury, intravenous salbutamol in acute respiratory distress syndrome, plasma-derived protein C concentrate, aprotinin in high-risk cardiac surgery, cysteine prodrug, hypothermia in meningitis, methylprednisolone in traumatic brain injury, and albumin in traumatic brain injury (72% of agreement). Overall, a high consistency (ranging from 80% to 90%) between agreement and clinical practice was observed. CONCLUSION: The authors identified 12 clinical interventions showing increased mortality supported by randomized controlled trials with nonconflicting evidence, and wide agreement upon clinicians on a global scale.

A Systematic Review and International Web-Based Survey of Randomized Controlled Trials in the Perioperative and Critical Care Setting: Interventions Reducing Mortality.

The authors aimed to identify interventions documented by randomized controlled trials (RCTs) that reduce mortality in adult critically ill and perioperative patients, followed by a survey of clinicians' opinions and routine practices to understand the clinicians' response to such evidence. The authors performed a comprehensive literature review to identify all topics reported to reduce mortality in perioperative and critical care settings according to at least 2 RCTs or to a multicenter RCT or to a single-center RCT plus guidelines. The authors generated position statements that were voted on online by physicians worldwide for agreement, use, and willingness to include in international guidelines. From 262 RCT manuscripts reporting mortality differences in the perioperative and critically ill settings, the authors selected 27 drugs, techniques, and strategies (66 RCTs, most frequently published by the New England Journal of Medicine [13 papers], Lancet [7], and Journal of the American Medical Association [5]) with an agreement ≥67% from over 250 physicians (46 countries). Noninvasive ventilation was the intervention supported by the largest number of RCTs (n = 13). The concordance between agreement and use (a positive answer both to "do you agree" and "do you use") showed differences between Western and other countries and between anesthesiologists and intensive care unit physicians. The authors identified 27 clinical interventions with randomized evidence of survival benefit and strong clinician support in support of their potential life-saving properties in perioperative and critically ill patients with noninvasive ventilation having the highest level of support. However, clinician views appear affected by specialty and geographical location.

Feasibility, safety and efficacy of COVID-19 severe acute respiratory distress syndrome management without invasive mechanical ventilation.

BACKGROUND: COVID-19 acute respiratory distress syndrome (ARDS) is often managed with mechanical ventilation (MV), requiring sedation and paralysis, with associated risk of complications. There is limited evidence on the use of high flow nasal cannula (HFNC). We hypothesized that management of COVID-19 ARDS without MV is feasible. METHODS: Included were all adult patients diagnosed with COVID-19 ARDS, with PaO2/FiO2 ratio <100 at admission, and whose management was initially performed without MV. We evaluated need for intubation during ICU stay, mortality and hospital/ICU length of stay (LOS). RESULTS: Out of 118 patients, 41 were managed only with HFNC from hospital admission (and at least during first 24 hours in ICU) and had a PaO2/FiO2 ratio <100 (72.9±13.0). Twenty-nine out of 41 patients never required MV: 24 of them survived and were discharged home. Their median ICU LOS was 11 (7-17) days, and their hospital LOS was 29 (18-45) days. We identified PaO2/FiO2 ratio at ICU admission as the only significant predictor for need for MV during ICU stay. We also identified age, length of non-invasive respiratory support before ICU admission, mean value of PaO2/FiO2 ratio during first half and whole ICU stay as predictors of mortality. CONCLUSIONS: It is safe to monitor in ICU and use HFNC in patients affected by COVID-19 ARDS who initially present data suggesting an early need for intubation. The 41 patients admitted with a PaO2/FiO2 ratio <100 and initially treated only with HFNC show a 22% mortality that is in the lower range of what is reported in recent literature.

Halogenated Agents and Cardiovascular Surgery: Has Mortality Really Decreased?

Halogenated anesthetic agents (desflurane, isoflurane and sevoflurane) may have cardioprotective properties at therapeutic doses against myocardial intraoperative ischemia-reperfusion injury. Cardioprotection mechanisms are related to mitochondrial and anti-apoptotic signaling pathways. Experimentals and human studies have proven that their use may reduce morbidity and mortality in the setting of cardiac surgery, including a reduction in myocardial infarct size and mechanical ventilation needs. In contrast, total intra-venous propofol based anesthesia may be detrimental. In the present review, we show the rationale for the perioperative use of halogenated anesthetics based on mechanisms of action, experimental research and human studies. Considerations and major concerns regarding their use, the present evidence for their use in other areas, such as major non-cardiac surgery and intensive care unit patients, and future perspectives are also discussed.