Dobutamine

CMR-FT was performed using dedicated software provided by TomTec Imaging Systems (2D CPA MR, Cardiac Performance Analysis, Version 1.1.2.36) and Circle Cardiovascular Imaging (Tissue Tracking, cvi⁴²). For the purposes of this paper the different software tools are referred to as “TomTec” and “Circle”. Identical short axis sections were analysed at apical, mid-ventricular, and basal levels to compare short-axis-derived global LV Ecc and Err (based on all three analysed sections) alongside the time-to-peak (TPK) strain duration. Short-axis CMR images were analysed at rest and with 10 and 20 μg/kg/min dobutamine, respectively. Myocardial torsion was calculated from the rotational raw data provided with the TomTec software using an in-house-developed post-processing tool as recently described by the authors' group.¹⁵ (link) The model underlying this assessment makes use of linear interpolation and takes standardized rotational measurements at 25 and 75% LV locations after the analysis of a whole LV short axis stack. In this model the most apical section showing LV cavity at end-systole is considered at the 0% LV location and the most basal section including a complete circumference of myocardium at end-systole is considered at the 100% LV location. In comparison to TomTec, Circle commercially provides torsion measurements within its software interface. This is done by manually choosing an apical and basal section. In order to allow accurate comparisons between vendors, apical and basal sections at the closest distance to 25% and 75% LV locations were chosen.
With both types of software LV endocardial and epicardial borders were manually delineated in all analysed sections with the initial contour set at end-diastole. In case of insufficient tracking, as defined by apparent deviations of the contours from the endocardial and epicardial borders, contours were manually corrected and the algorithm reapplied. The tracking was repeated three times in all sections. One single observer analysed all data using both types of software. Intra-observer variability was derived from the repetition of the analysis after 4 weeks. The analysis of a second skilled observer for both types of software was used to assess interobserver reproducibility.
Reported results are based on the average of three analysis repetitions (R3). To study the impact of repeated measurements on reproducibility, the reproducibility derived from results based on a single repetition (R1), averaged results for two (R2) and three repetitions (R3) were compared with each other.

This study was a restrictive observation study from the Medical Information Mart for Intensive Care IV (MIMIC-IV version 0.4) database from 2008 to 2019 [24 ]. An individual who has finished the Collaborative Institutional Training Initiative examination (Certification number 35931520 for author Zhou) can access the database. This is a longitudinal, single-center database including 257,366 individuals and 196,527 adults, and 11,263 patients with sepsis (Defined by sepsis-3 criteria [1 (link)]). In our study, we extracted patients’ parameters containing age, gender, ethnic group, admission type, insurance condition, the first 24-h Sequential Organ Failure Assessment (SOFA) score, Simplified Acute Physiology Score II (SAPS) score, mean arterial blood pressure (MAP), heart rate, respiratory rate, temperature, SpO₂, total urine output during the first 24 h after ICU admission, lactate level, the use of vasopressors, weight, mechanical ventilation, renal replacement therapy (RRT), the stage of acute kidney injury (AKI), anamnesis (myocardial infarction, cancer, renal disease, cirrhosis and diabetes) and the type and volume of their fluid administration during the whole ICU stay. Vasopressors included norepinephrine, phenylephrine, epinephrine, vasopressin, dopamine, and dobutamine. For the antibiotics, Carbapenems (meropenem), Glycopeptide (vancomycin), β-lactams (ceftriaxone, cefotaxime, and cefepime), and Aminoglycosides (gentamicin and amikacin) were extracted into our analysis. In this study, types of administration for crystalloids and albumin including normal saline and lactated Ringer’s (LR) solution, while 5% and 25% HSA for colloids. The code of data extraction is available on Github (https://github.com/MIT-LCP/mimic-iv).
Adults patients (≥ 18 years) with sepsis and complete fluid administration records were screened in the analysis. The following exclusion criteria were used: (1) patients who have not received any crystalloids administration; (2) patients who received albumin longer than 24 h after the initiation of crystalloids administration or preceded the crystalloids. For patients who had ICU admission more than once, only data of the first ICU admission of the first hospital stay were included.

Patients admitted over a period of one year (from May 2013 to May 2014) to the ICU of the University of Bari Academic Hospital were considered for enrollment in the study. The local ethics committee (Azienda Ospedaliero-Universitaria Policlinico di Bari Ethic Committee, protocol number: 257/C.E. March 2013) approved the investigative protocol, and written informed consent was obtained from each patient or next of kin. A physician not involved in the study was always present for patient care. Our clinical trial was registered with clinicalTrials.gov, identifier: NCT02473172.
Patients were eligible for the study if they were older than 18 years, oro-tracheally or naso-tracheally intubated, had been ventilated for acute respiratory failure with CMV (flow-limited, pressure-limited or volume-targeted pressure-limited) for at least 72 hours consecutively and were candidates for assisted ventilation. The criteria for defining the readiness to assisted ventilation were: a) improvement of the condition leading to acute respiratory failure; b) positive end-expiratory pressure (PEEP) lower than 10 cmH₂O and inspiratory oxygen fraction (FiO₂) lower than 0,5; c) Richmond agitation sedation scale (RASS) score between 0 and –1 [23 (link)] obtained with no or moderate levels of sedation and, d) ability to trigger the ventilator, i.e., to decrease pressure airway opening (P_AO) >3–4 cmH₂O during a brief (5–10 s) end-expiratory occlusion test. Other criteria included hemodynamic stability without vasopressor or inotropes (excluding a dobutamine and dopamine infusion <5 gamma/Kg/min and 3 gamma/Kg/min, respectively) and normothermia. Patients were excluded from the study if they were affected by neurological or neuromuscular pathology and/or known phrenic nerve dysfunction, or if they had any contraindication to the insertion of a nasogastric tube (for example: recent upper gastrointestinal surgery, esophageal varices).

General anesthesia was induced with 0.1 mg/kg BW diazepam (Ziapam 5 mg/kg, Ecuphar GmbH, Greifswald, Germany) and 2.2 mg/kg BW ketamine (Narketan, Vétoquinol GmbH, Ismaning, Germany) after premedication with 0.7 mg/kg BW xylazine (Xylavet 20 mg/ml, CP-Pharma GmbH, Burgdorf, Germany). Anesthesia was maintained with isoflurane (Isofluran CP, CP-Pharma GmbH) in 100% oxygen, and continuous rate infusions with lactated Ringer's solution (Ringer-Laktat EcobagClick, B. Braun Melsungen AG, Melsungen, Germany) and dobutamine (Dobutamin-ratiopharm 250 mg, Ratiopharm GmbH, Ulm, Germany) were given to effect, to maintain the mean arterial blood pressure between 60 and 80 mmHg. A routine pre-umbilical median laparotomy was performed in dorsal recumbency following aseptic preparation. Segmental small intestinal ischemia was induced in 1.5 m jejunum by occlusion of the mesenteric vessels with umbilical tape. The ligature was tightened under monitoring of intestinal microperfusion with microlightguide spectophotometry and laser Doppler flowmetry (O₂C, LEA Medizintechnik GmbH, Giessen, Germany), and the ligature was tied when the blood flow was reduced by 90% of the pre-ischemic measurement. The ischemia was maintained for 90 min. In group C, the ligature was released without manipulation of the vessels and reperfusion was initiated without delay. In group IPoC, postconditioning was implemented after release of ischemia by clamping the mesenteric vessels for three cycles of 30 s, alternated with 30 s of reperfusion. This was followed by 120 min of reperfusion in both groups. Subsequently, the horses were euthanized with 90 mg/kg BW pentobarbital intravenously (Release 50 mg/mL, WDT eG, Garbsen, Germany) without regaining consciousness.

The VVR score was calculated at 1 h, 24 h, and 48 h after surgery, as follows: VIS + ventilation index (VI) + renal score (change in serum creatinine from baseline × 10).
VIS was calculated using the following equation:
Dopamine dose (μg/kg/min) + Dobutamine dose (μg/kg/min) + 100 × Epinephrine dose (μg/kg/min) + 10 × Milrinone dose (μg/kg/min) + 10,000 × Vasopressin dose (μg/kg/min) + 100 × Norepinephrine dose (μg/kg/min) (7 (link)).
VI was calculated using the following formula:
VI = respiratory rate (RR) × (PIP − PEEP) × PaCO₂/1,000; ΔCr was calculated by subtracting serum creatinine (in mg/dL) at the time of each measurement from the preoperative serum creatinine and VVR using the following formula:
VVR = VIS + VI + (ΔCr × 10) (8 (link)).
For patients whose postoperative serum creatinine values were less than preoperative values, ΔCr was taken as 0. For patients not requiring ventilator support at the time of measurement, VI was taken as 0.