Intraoperative individualization of positive-end-expiratory pressure through electrical impedance tomography or esophageal pressure assessment: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE: This systematic review of randomized-controlled trials (RCTs) with meta-analyses aimed to compare the effects on intraoperative arterial oxygen tension to inspired oxygen fraction ratio (PaO2/FiO2), exerted by positive end-expiratory pressure (PEEP) individualized trough electrical impedance tomography (EIT) or esophageal pressure (Pes) assessment (intervention) vs. PEEP not tailored on EIT or Pes (control), in patients undergoing abdominal or pelvic surgery with an open or laparoscopic/robotic approach. METHODS: PUBMED®, EMBASE®, and Cochrane Controlled Clinical trials register were searched for observational studies and RCTs from inception to the end of August 2022. Inclusion criteria were: RCTs comparing PEEP titrated on EIT/Pes assessment vs. PEEP not individualized on EIT/Pes and reporting intraoperative PaO2/FiO2. Two authors independently extracted data from the enrolled investigations. Data are reported as mean difference and 95% confidence interval (CI). RESULTS: Six RCTs were included for a total of 240 patients undergoing general anesthesia for surgery, of whom 117 subjects in the intervention group and 123 subjects in the control group. The intraoperative mean PaO2/FiO2 was 69.6 (95%CI 32.-106.4 ) mmHg higher in the intervention group as compared with the control group with 81.4% between-study heterogeneity (p < 0.01). However, at meta-regression, the between-study heterogeneity diminished to 44.96% when data were moderated for body mass index (estimate 3.45, 95%CI 0.78-6.11, p = 0.011). CONCLUSIONS: In patients undergoing abdominal or pelvic surgery with an open or laparoscopic/robotic approach, PEEP personalized by EIT or Pes allowed the achievement of a better intraoperative oxygenation compared to PEEP not individualized through EIT or Pes. PROSPERO REGISTRATION NUMBER: CRD 42021218306, 30/01/2023.

Lung ultrasound monitoring: impact on economics and outcomes.

PURPOSE OF REVIEW: This review aims to summarize the impact of lung ultrasonography (LUS) on economics and possible impact on patients' outcomes, proven its diagnostic accuracy in patients with acute respiratory failure. RECENT FINDINGS: Despite some previous ethical concerns on LUS examination, today this technique has showed several advantages. First, it is now clear that the daily use of LUS can provide a relevant cost reduction in healthcare of patients with acute respiratory failure, while reducing the risk of transport of patients to radiological departments for chest CT scan. In addition, LUS reduces the exposition to x-rays since can replace the bedside chest X-ray examination in many cases. Indeed, LUS is characterized by a diagnostic accuracy that is even superior to portable chest X-ray when performed by well trained personnel. Finally, LUS examination is a useful tool to predict the course of patients with pneumonia, including the need for hospitalization and ICU admission, noninvasive ventilation failure and orotracheal intubation, weaning success, and mortality. SUMMARY: LUS should be implemented not only in Intensive Care Units, but also in other setting like emergency departments. Since most data comes from the recent coronavirus disease 2019 pandemic, further investigations are required in Acute Respiratory Failure of different etiologies.

Diaphragmatic Kinetics Assessment by Tissue Doppler Imaging and Extubation Outcome.

BACKGROUND: The assessment of diaphragmatic kinetics through tissue Doppler imaging (dTDI) was recently proposed as a means to describe diaphragmatic activity in both healthy individuals and intubated patients undergoing weaning from mechanical ventilation. Our primary aim was to investigate whether the diaphragmatic excursion velocity measured with dTDI at the end of a spontaneous breathing trial (SBT) was different in subjects successfully extubated versus those who passed the trial but exhibited extubation failure within 48 h after extubation. METHODS: We enrolled 100 adult subjects, all of whom had successfully passed a 30-min SBT conducted in CPAP of 5 cm H2O. In cases of extubation failure within 48 h after liberation from invasive mechanical ventilation, subjects were re-intubated or supported through noninvasive ventilation. dTDI was performed at the end of the SBT to assess excursion, velocity, and acceleration. RESULTS: Extubation was successful in 79 subjects, whereas it failed in 21 subjects. The median (interquartile range [IQR]) inspiratory peak excursion velocity (3.1 [IQR 2.0-4.3] vs 1.8 [1.3-2.6] cm/s, P < .001), mean velocity (1.6 [IQR 1.2-2.4] vs 1.1 [IQR 0.8-1.4] cm/s, P < .001), and acceleration (8.8 [IQR 5.0-17.8] vs 4.2 [IQR 2.4-8.0] cm/s2, P = .002) were all significantly higher in subjects who failed extubation compared with those who were successfully extubated. Similarly, the median expiratory peak relaxation velocity (2.6 [IQR 1.9-4.5] vs 1.8 [IQR 1.2-2.5] cm/s, P < .001), mean velocity (1.1 [IQR 0.7-1.7] vs 0.9 [IQR 0.6-1.0] cm/s, P = .002), and acceleration (11.2 [IQR 9.1-19.0] vs 7.1 [IQR 4.6-12.0] cm/s2, P = .004) were also higher in the subjects who failed extubation. CONCLUSIONS: In our setting, at the end of SBT, subjects who developed extubation failure within 48 h after extubation experienced a greater diaphragmatic activation compared with subjects who were successfully extubated. (ClinicalTrials.gov registration NCT03962322.).

Critical Care Surge Capacity to Respond to the COVID-19 Pandemic in Italy: A Rapid and Affordable Solution in the Novara Hospital.

The rapid insurgence and spread of coronavirus disease 2019 (COVID-19) exceeded the limit of the intensive care unit (ICU) contingency plan of the Maggiore della Carità University Hospital (Novara, Italy) generating a crisis management condition. This brief report describes how a prompt response to the sudden request of invasive mechanical ventilation (IMV) was provided by addressing the key elements of health care system surge capacity from contingency to crisis. In a short time and at a relatively low cost, a structural modification of a hospital aisle allowed to convert the general ICU into a COVID-19 unit, increasing the number of COVID-19 critical care beds by 107%.

Assessment of Fluid Responsiveness in Prone Neurosurgical Patients Undergoing Protective Ventilation: Role of Dynamic Indices, Tidal Volume Challenge, and End-Expiratory Occlusion Test.

BACKGROUND: In patients in the prone position, the reliability of pulse pressure variation and stroke volume variation (PPV and SVV) and the use of functional hemodynamic tests to predict fluid responsiveness have not previously been established. Perioperatively, in this setting, optimizing fluid management can be challenging, and fluid overload is associated with both intraoperative and postoperative complications. We designed this study to assess the sensitivity and specificity of baseline PPV and SVV, the tidal volume (VT) challenge (VTC) and the end-expiratory occlusion test (EEOT) in predicting fluid responsiveness during elective spinal surgery. METHODS: The study protocol was started during a period of intraoperative hemodynamic stability after prone positioning and before the administration of any vasopressor: (1) at baseline, the controlled ventilation was set at 6 mL/kg of predicted body weight (PBW) (T0); (2) patients underwent the first EEOT (EEOT6) by interrupting the mechanical ventilation for 30 seconds; (3) the ventilation was set again at 6 mL/kg PBW for 1 minute (T1); (4) the VTC was applied by increasing the VT up to 8 mL/kg PBW for 1 minute; (5) the ventilation was kept at 8 mL/kg PBW for 1 minute (T2); (6) a second EEOT (EEOT8) was performed; (7) the VT was reduced back to 6 mL/kg PBW for 1 minute (T3); (8) a fluid challenge of 250 mL of Ringer's solution was infused over 10 minutes. After each step, a complete set of hemodynamic measurements was recorded. RESULTS: Neither PPV and SVV values recorded at T3 nor the EEOT6 or the EEOT8 predicted fluid responsiveness. The change in PPV after VTC application predicted fluid responsiveness with an area under the curve of 0.96 (95% confidence interval, 0.87-1.00), showing a sensitivity of 95.2% and a specificity of 94.7%, using a cutoff increase of 12.2%. The change in SVV after VTC application predicted fluid responsiveness with an area under the curve 0.96 (95% confidence interval, 0.89-1.00) showing a sensitivity of 95.2% and a specificity of 94.7%, using a cutoff increase of 8.0%. A linear correlation between stroke volume index changes after fluid challenge administration and the changes in PPV and SVV after VTC application was observed (r = 0.71; P < .0001 and r = 0.68; P < .0001, respectively). CONCLUSIONS: In prone elective neurosurgical patients, the baseline values of PPV and SVV and the EEOT fail to predict fluid responsiveness, while the VTC is a very reliable functional hemodynamic test and could be helpful in guiding intraoperative fluid therapy.

Diaphragmatic Ultrasound Assessment in Subjects With Acute Hypercapnic Respiratory Failure Admitted to the Emergency Department.

BACKGROUND: Early identification of noninvasive ventilation (NIV) outcome predictors in patients with COPD who are experiencing acute hypercapnic respiratory failure consequent to exacerbation or pneumonia is a critical issue. The primary aim of this study was to investigate the feasibility of performing diaphragmatic ultrasound for excursion, thickness, and thickening fraction in highly dyspneic subjects with COPD admitted to the emergency department for exacerbation or pneumonia, before starting NIV (T0) and after the first (T1) and second hour (T2) of treatment. Secondarily, we determined whether these variables predicted early NIV failure. METHODS: Adult subjects with COPD admitted to the emergency department for exacerbation or pneumonia requiring NIV were eligible. Right-sided diaphragmatic excursion, bilateral thickness, thickening fraction, and arterial blood gas analyses were performed at T0, T1, and T2. Feasibility was estimated by considering the number of subjects whose diaphragmatic function could be evaluated at each time point. At T2, subjects were classified in 2 subgroups according to early NIV failure, which was defined as the inability to achieve a pH ≥ 7.35; the ability to achieve pH ≥ 7.35 indicated NIV success. RESULTS: Of the 22 subjects enrolled, 21 underwent complete diaphragm ultrasound evaluation (ie, right excursion and bilateral thickness at T0, T1, and T2) for a total of 63 excursion and 126 thickness assessments. At T2, 12 NIV successes and 9 NIV failures were recorded. Diaphragmatic excursion was greater in NIV successes than in NIV failures at T0 (1.92 [1.22-2.54] cm versus 1.00 [0.60-1.41] cm, P = .02), at T1 (2.14 [1.76-2.77] cm versus 0.93 [0.82-1.27] cm, P = .007), and at T2 (1.99 [1.63-2.54] cm versus 1.20 [0.79-1.41] cm, P = .008), respectively. Diaphragmatic thickness and thickening fraction were similar in both groups. CONCLUSIONS: In our emergency department setting, diaphragm ultrasound was a feasible and reliable tool to monitor highly dyspneic acute hypercapnic respiratory failure subjects with COPD undergoing NIV. (ClinicalTrials.gov registration NCT03314883.).

Sigh maneuver to enhance assessment of fluid responsiveness during pressure support ventilation.

BACKGROUND: Assessment of fluid responsiveness is problematic in intensive care unit (ICU) patients, in particular for those undergoing modes of partial support, such as pressure support ventilation (PSV). We propose a new test, based on application of a ventilator-generated sigh, to predict fluid responsiveness in ICU patients undergoing PSV. METHODS: This was a prospective bi-centric interventional study conducted in two general ICUs. In 40 critically ill patients with a stable ventilatory PSV pattern and requiring volume expansion (VE), we assessed the variations in arterial systolic pressure (SAP), pulse pressure (PP) and stroke volume index (SVI) consequent to random application of 4-s sighs at three different inspiratory pressures. A radial arterial signal was directed to the MOSTCARE™ pulse contour hemodynamic monitoring system for hemodynamic measurements. Data obtained during sigh tests were recorded beat by beat, while all the hemodynamic parameters were averaged over 30 s for the remaining period of the study protocol. VE consisted of 500 mL of crystalloids over 10 min. A patient was considered a responder if a VE-induced increase in cardiac index (CI) ≥ 15% was observed. RESULTS: The slopes for SAP, SVI and PP of were all significantly different between responders and non-responders (p < 0.0001, p = 0.0004 and p < 0.0001, respectively). The AUC of the slope of SAP (0.99; sensitivity 100.0% (79.4-100.0%) and specificity 95.8% (78.8-99.9%) was significantly greater than the AUC for PP (0.91) and SVI (0.83) (p = 0.04 and 0.009, respectively). The SAP slope best threshold value of the ROC curve was - 4.4° from baseline. The only parameter found to be independently associated with fluid responsiveness among those included in the logistic regression was the slope for SAP (p = 0.009; odds ratio 0.27 (95% confidence interval (CI95) 0.10-0.70)). The effects produced by the sigh at 35 cmH20 (Sigh35) are significantly different between responders and non-responders. For a 35% reduction in PP from baseline, the AUC was 0.91 (CI95 0.82-0.99), with sensitivity 75.0% and specificity 91.6%. CONCLUSIONS: In a selected ICU population undergoing PSV, analysis of the slope for SAP after the application of three successive sighs and the nadir of PP after Sigh35 reliably predict fluid responsiveness. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry, ACTRN12615001232527 . Registered on 10 November 2015.

Transthoracic echocardiographic assessment of cardiac output in mechanically ventilated critically ill patients by intensive care unit physicians / Avaliação ecocardiográfica transtorácica do débito cardíaco feita por médicos da unidade de terapia intensiva em pacientes críticos sob ventilação mecânica

Abstract Background and objectives: Transthoracic echocardiography may potentially be useful to obtain a prompt, accurate and non-invasive estimation of cardiac output. We evaluated whether non-cardiologist intensivists may obtain accurate and reproducible cardiac output determination in hemodynamically unstable mechanically ventilated patients. Methods: We studied 25 hemodynamically unstable mechanically ventilated intensive care unit patients with a pulmonary artery catheter in place. Cardiac output was calculated using the pulsed Doppler transthoracic echocardiography technique applied to the left ventricular outflow tract in apical 5 chamber view by two intensive care unit physicians who had received a basic Transthoracic Echocardiography training plus a specific training focused on Doppler, left ventricular outflow tract and velocity-time integral determination. Results: Cardiac output assessment by transthoracic echocardiography was feasible in 20 out of 25 enrolled patients (80%) and showed an excellent inter-operator reproducibility (Pearson correlation test r = 0.987; Cohen's K = 0.840). Overall, the mean bias was 0.03 L.min-1, with limits of agreement -0.52 and +0.57 L.min-1. The concordance correlation coefficient (ρc) was 0.986 (95% IC 0.966-0.995) and 0.995 (95% IC 0.986-0.998) for physician 1 and 2, respectively. The value of accuracy (Cb) of COTTE measurement was 0.999 for both observers. The value of precision (ρ) of COTTE measurement was 0.986 and 0.995 for observer 1 and 2, respectively. Conclusions: A specific training focused on Doppler and VTI determination added to the standard basic transthoracic echocardiography training allowed non-cardiologist intensive care unit physicians to achieve a quick, reproducible and accurate snapshot cardiac output assessment in the majority of mechanically ventilated intensive care unit patients.

Resumo Justificativa e objetivos: A ecocardiografia transtorácica pode ser potencialmente útil para obter uma estimativa rápida, precisa e não invasiva do débito cardíaco. Avaliamos se os intensivistas não cardiologistas podem obter uma determinação precisa e reprodutível do débito cardíaco em pacientes mecanicamente ventilados e hemodinamicamente instáveis. Métodos: Avaliamos 25 pacientes em unidade de terapia intensiva, mecanicamente ventilados, hemodinamicamente instáveis, com cateteres de artéria pulmonar posicionados. O débito cardíaco foi calculado com a técnica de ecocardiografia transtorácica com Doppler pulsátil aplicada à via de saída do ventrículo esquerdo no corte apical (5-câmaras) por dois médicos intensivistas que receberam treinamento básico em ecocardiografia transtorácica e treinamento específico focado em Doppler, via de saída do ventrículo esquerdo e determinação da integral de tempo-velocidade. Resultados: A avaliação do débito cardíaco pelo ecocardiograma transtorácico foi factível em 20 dos 25 pacientes inscritos (80%) e mostrou excelente reprodutibilidade entre operadores (teste de correlação de Pearson r = 0,987; K de Cohen = 0,840). No geral, o viés médio foi de 0,03 L.min-1, com limites de concordância de -0,52 e +0,57 L.min-1. O coeficiente de correlação de concordância (ρc) foi 0,986 (95% IC 0,966-0,995) e 0,995 (95% IC 0,986-0,998) para os médicos 1 e 2, respectivamente. O valor de precisão (Cb) da mensuração de COTTE foi de 0,999 para ambos os observadores. O valor de precisão (ρ) da mensuração de COTTE foi de 0,986 e 0,995 para os observadores 1 e 2, respectivamente. Conclusões: Um treinamento específico focado na determinação do Doppler e VTI, adicionado ao treinamento padrão em ecocardiografia transtorácica básica, permitiu que médicos não cardiologistas da unidade de terapia intensiva obtivessem uma avaliação rápida, reprodutível e precisa do débito cardíaco instantâneo na maioria dos pacientes mecanicamente ventilados em unidade de terapia intensiva.

[Transthoracic echocardiographic assessment of cardiac output in mechanically ventilated critically ill patients by intensive care unit physicians]. / Avaliação ecocardiográfica transtorácica do débito cardíaco feita por médicos da unidade de terapia intensiva em pacientes críticos sob ventilação mecânica.

BACKGROUND AND OBJECTIVES: Transthoracic echocardiography may potentially be useful to obtain a prompt, accurate and non-invasive estimation of cardiac output. We evaluated whether non-cardiologist intensivists may obtain accurate and reproducible cardiac output determination in hemodynamically unstable mechanically ventilated patients. METHODS: We studied 25 hemodynamically unstable mechanically ventilated intensive care unit patients with a pulmonary artery catheter in place. Cardiac output was calculated using the pulsed Doppler transthoracic echocardiography technique applied to the left ventricular outflow tract in apical 5 chamber view by two intensive care unit physicians who had received a basic Transthoracic Echocardiography training plus a specific training focused on Doppler, left ventricular outflow tract and velocity-time integral determination. RESULTS: Cardiac output assessment by transthoracic echocardiography was feasible in 20 out of 25 enrolled patients (80%) and showed an excellent inter-operator reproducibility (Pearson correlation test r=0.987; Cohen's K=0.840). Overall, the mean bias was 0.03L.min-1, with limits of agreement -0.52 and +0.57L.min-1. The concordance correlation coefficient (ρc) was 0.986 (95% IC 0.966-0.995) and 0.995 (95% IC 0.986-0.998) for physician 1 and 2, respectively. The value of accuracy (Cb) of COTTE measurement was 0.999 for both observers. The value of precision (ρ) of COTTE measurement was 0.986 and 0.995 for observer 1 and 2, respectively. CONCLUSIONS: A specific training focused on Doppler and VTI determination added to the standard basic transthoracic echocardiography training allowed non-cardiologist intensive care unit physicians to achieve a quick, reproducible and accurate snapshot cardiac output assessment in the majority of mechanically ventilated intensive care unit patients.