What’s the best assessment of preload after cardiac surgery?

Objective: The assessment of the role of transesophageal echocardiography and invasive tests with pulmonary modified catheter to monitor the preload indexes in patients in intensive- care-unit after cardiac coronary surgery. Materials and Methods: Between January and December 2004 24 patients (14 male, 10 female) with coronary artery disease were prospectively enrolled for preload assessment during off-pump myocardial revascularization. Pulmonary Capillary Wedge Pressure (PCWP), Left Ventricular End Diastolic Indexed Area (LVEDAI), Δ Aortic Velocity (ΔVAo), Right Ventricular End Diastolic Volume (RVEDVI) as preload indexes were evaluated. Transesophageal echocardiography and pulmonary modified catheter monitoring were performed during the preoperative period at T1 and after fluid infusion (T2). Patients were considered Responders (R) or No Responders (NR) if the Stroke Volume Index increase at T2 was >20% with respect to T1. Results: Mean T1 PCWP was similar in both groups (12.8±2.2 in R vs. 11.4±3 mmHg in NR; p=NS) and mean increase of PCWP at T2 was similar in both groups (1.5±0.3% in R vs. 1.2±3% in NR; p=NS). Mean T1 RVEDVI was similar in both groups (97.33±34 in R vs. 101±21 ml/m2 in NR; p=NS); T2 RVEDVI was similar in R and NR Groups (122.11±49 vs. 138.54±30 ml/m2; p=NS); mean T1 and T2 LVEDAI was similar in R and NR (11.2±3.5 vs. 10.2±2.3 at T1 and 14.04±3.35 vs. 14.67±2.1 cm2/m2 at T2 respectively; p=NS). Higher mean value of T1 ΔVAo (20±7% in R vs. 10±2% in NR; p=0.006) were recorded while similar mean value of T2 ΔVAo were observed (11±3% in R vs. 5±2% in NR; p=0.743). Correlation index between T1 and T2 ΔVAo (R=0.82) in R was significant (p=0.0002), while correlation index between T1 and T2 ΔVAo (R=0.11) in NR was not significant. Conclusions: Our study showed in patients soon after coronary cardiac surgery ΔVAo is the only predictor of “fluid responsiveness” and of ventricular compliance

Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE): study protocol for a randomized controlled trial

Background: Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients. Methods/design The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index ≥35 kg/m2 scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH2O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH2O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint. Discussion To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs. Trial registration ClinicalTrials.gov identifier: NCT02148692. Registered on 23 May 2014; last updated 7 June 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-1929-0) contains supplementary material, which is available to authorized users

Role of analgesia in control of the discomfort and pain in endoscopic colonic polypectomy

BACKGROUND: The first choice technique for the resection of colorectal polyps is without doubt the Endoscopic polypectomy, which plays a significant role in the prevention of colorectal cancer. The purpose of this study was to evaluate the sedation of patients undergoing polypectomy in reducing pain and discomfort. METHODS: A 200 patients case-control study shows the role of analgesia and sedation in endoscopic procedures. Patients submitted to a colonoscopy to perform a polypectomy, were allocated in two different groups according to receive or not a sedation. A continuous vital signs checking has been applied, and a comparison of pain and discomfort felt by the two groups, shows a statistically minor presence of the two symptoms in analgesia group with a shorter caecum reaching time as well. RESULTS: Eighty-five percent of group A patients described the procedure as painful according to VAS pain scale (VAS>6) and the 90% reported moderate discomfort as well. Comparing the two groups is possible to observe with a statistical significativity that 38,8% of group B patients reported the procedure as painful, while the 85% of group A patients. CONCLUSIONS: The use of analgesia drugs such as short life benzodiazepine is the favorite particularly in well set outpatient according to our study outcomes, leading to a less discomfort related procedure and a better procedure performance

Quantitative Metabolomics of Tissue, Perfusate, and Bile from Rat Livers Subjected to Normothermic Machine Perfusion

Machine perfusion (MP) allows the maintenance of liver cells in a metabolically active state ex vivo and can potentially revert metabolic perturbations caused by donor warm ischemia, procurement, and static cold storage (SCS). The present preclinical research investigated the metabolic outcome of the MP procedure by analyzing rat liver tissue, bile, and perfusate samples by means of high-field (600 MHz) nuclear magnetic resonance (NMR) spectroscopy. An established rat model of normothermic MP (NMP) was used. Experiments were carried out with the addition of an oxygen carrier (OxC) to the perfusion fluid (OxC-NMP, n = 5) or without (h-NMP, n = 5). Bile and perfusate samples were collected throughout the procedure, while biopsies were only taken at the end of NMP. Two additional groups were: (1) Native, in which tissue or bile specimens were collected from rats in resting conditions; and (2) SCS, in which biopsies were taken from cold-stored livers. Generally, NMP groups showed a distinctive metabolomic signature in all the analyzed biological matrices. In particular, many of the differentially expressed metabolites were involved in mitochondrial biochemical pathways. Succinate, acetate, 3-hydroxybutyrate, creatine, and O-phosphocholine were deeply modulated in ex vivo perfused livers compared to both the Native and SCS groups. These novel results demonstrate a broad modulation of mitochondrial metabolism during NMP that exceeds energy production and redox balance maintenance

Alkaline Liquid Ventilation of the Membrane Lung for Extracorporeal Carbon Dioxide Removal (ECCO2R): In Vitro Study

Extracorporeal carbon dioxide removal (ECCO2R) is a promising strategy to manage acute respiratory failure. We hypothesized that ECCO2R could be enhanced by ventilating the membrane lung with a sodium hydroxide (NaOH) solution with high CO2 absorbing capacity. A computed mathematical model was implemented to assess NaOH–CO2 interactions. Subsequently, we compared NaOH infusion, named “alkaline liquid ventilation”, to conventional oxygen sweeping flows. We built an extracorporeal circuit with two polypropylene membrane lungs, one to remove CO2 and the other to maintain a constant PCO2 (60 ± 2 mmHg). The circuit was primed with swine blood. Blood flow was 500 mL × min−1. After testing the safety and feasibility of increasing concentrations of aqueous NaOH (up to 100 mmol × L−1), the CO2 removal capacity of sweeping oxygen was compared to that of 100 mmol × L−1 NaOH. We performed six experiments to randomly test four sweep flows (100, 250, 500, 1000 mL × min−1) for each fluid plus 10 L × min−1 oxygen. Alkaline liquid ventilation proved to be feasible and safe. No damages or hemolysis were detected. NaOH showed higher CO2 removal capacity compared to oxygen for flows up to 1 L × min−1. However, the highest CO2 extraction power exerted by NaOH was comparable to that of 10 L × min−1 oxygen. Further studies with dedicated devices are required to exploit potential clinical applications of alkaline liquid ventilation

Effects of two stepwise lung recruitment strategies on respiratory function and haemodynamics in anaesthetised pigs: A randomised crossover study

BACKGROUND: Lung recruitment manoeuvres and positive end-expiratory pressure (PEEP) can improve lung function during general anaesthesia. Different recruitment manoeuvre strategies have been described in large international trials: in the protective ventilation using high vs. low PEEP (PROVHILO) strategy, tidal volume (VT) was increased during volume-controlled ventilation; in the individualised peri-operative open-lung approach vs. standard protective ventilation in abdominal surgery (iPROVE) strategy, PEEP was increased during pressure-controlled ventilation. OBJECTIVES: To compare the effects of the PROVHILO strategy and the iPROVE strategy on respiratory and haemodynamic variables. DESIGN: Randomised crossover study. SETTING: University hospital research facility. ANIMALS: A total of 20 juvenile anaesthetised pigs. INTERVENTIONS: Animals were assigned randomly to one of two sequences: PROVHILO strategy followed by iPROVE strategy or vice-versa (n = 10/sequence). In the PROVHILO strategy, VT was increased stepwise by 4 ml kg-1 at a fixed PEEP of 12 cmH2O until a plateau pressure of 30 to 35 cmH2O was reached. In the iPROVE strategy, at fixed driving pressure of 20 cmH2O, PEEP was increased up to 20 cmH2O followed by PEEP titration according to the lowest elastance of the respiratory system (ERS). MAIN OUTCOME MEASURES: We assessed regional transpulmonary pressure (Ptrans), respiratory system mechanics, gas exchange and haemodynamics, as well as the centre of ventilation (CoV) by electrical impedance tomography. RESULTS: During recruitment manoeuvres with the PROVHILO strategy compared with the iPROV strategy, dorsal Ptrans was lower at end-inspiration (16.3 ± 2.7 vs. 18.6 ± 3.1 cmH2O, P = 0.001) and end-expiration (4.8 ± 2.6 vs. 8.8 ± 3.4 cmH2O, P  < 0.001), and mean arterial pressure (MAP) was higher (77 ± 11 vs. 60 ± 14 mmHg, P < 0.001). At 1 and 15 min after recruitment manoeuvres, ERS was higher in the PROVHILO strategy than the iPROVE strategy (24.6 ± 3.9 vs. 21.5 ± 3.4 and 26.7 ± 4.3 vs. 24.0 ± 3.8 cmH2O l-1; P  < 0.001, respectively). At 1 min, PaO2 was lower in PROVHILO compared with iPROVE strategy (57.1 ± 6.1 vs. 59.3 ± 5.1 kPa, P = 0.013), but at 15 min, values did not differ. CoV did not differ between strategies. CONCLUSION: In anaesthetised pigs, the iPROVE strategy compared with the PROVHILO strategy increased dorsal Ptrans at the cost of lower MAP during recruitment manoeuvres, and decreased ERS thereafter, without consistent improvement of oxygenation or shift of the CoV. TRIAL REGISTRATION: This study was registered and approved by the Landesdirektion Dresden, Germany (DD24-5131/338/28)