The effects of vasopressors with and without dobutamine on haemodynamics, metabolism and gut injury during endotoxic shock in rabbits. A controlled study.

INTRODUCTION: Vasopressors increase arterial pressure but they may have deleterious effects on mesenteric blood flow. We aimed to evaluate the response of gut biomarkers and superior mesenteric blood flow to different vasopressors with and without dobutamine. MATERIAL AND METHODS: Thirty New Zealand rabbits were included and randomly allocated to 5 groups: group A - sham group; group B - norepinephrine; group C - norepinephrine plus dobutamine; group D - vasopressin; and group E - vasopressin plus dobutamine. Mean arterial pressure (MAP) target was greater than 60 mmHg. Endotoxic shock was induced by intra-venous injection of lipopolysaccharide (LPS) in four of the five groups. Aortic blood flow (Qao), superior mesenteric artery flow (QSMA) and lactate were measured after LPS injection. Enterocyte damage was evaluated by measurements of serum citrulline and intestinal fatty acid-binding protein (I-FABP) after 4 h. RESULTS: The largest reduction in Qao occurred in group D (64 ± 17.3 to 38 ± 7.5 mL min-1; P = 0.04). QSMA also declined significantly in groups D and E and remained lower than in the other groups over 4 h (group D - baseline: 65 ± 31; 1 h: 37 ± 10; 2 h: 38 ± 10; 3 h: 46 ± 26; and 4 h: 48 ± 15 mL min-1; P < 0.005; group E - baseline: 73 ± 14; 1 h: 28 ± 4.0; 2 h: 37 ± 6.4; 3 h: 40 ± 11; and 4 h: 48 ± 11; P < 0.005; all in mL min-1). Serum citrulline was significantly lower in groups D (P = 0.014) and E (P = 0.019) in comparison to group A. The fluid administration regimen was similar in all groups. CONCLUSIONS: Vasopressin seems to negatively impact gut enterocyte function during endotoxic shock despite the association of an inodilator and adequate fluid replacement.

Intraoperative haemodynamic optimisation therapy with venoarterial carbon dioxide difference and pulse pressure variation - does it work?

BACKGORUND: Current evidence suggests that intraoperative goal-directed haemodynamic therapy (GDT) should be considered for high-risk patients undergoing major gastrointestinal surgery. We aimed to evaluate if an algorithm using venoarterial carbon dioxide difference (CO2 gap) and pulse pressure variation (PPV) as therapeutic targets during GDT would decrease the major complications after gastrointestinal surgery. METHODS: This was a before-and-after study (n = 204) performed in a tertiary hospital on patients who underwent elective open major gastrointestinal surgeries. The inclusion criteria were surgeries expected to last more than two hours, family and physician's agreement on total postoperative support, and survival expectancy of at least three months. The exclusion criteria were previous haemodynamic instability, presence of infection, cardiac arrhythmias, and emergency surgery. In the intervention group (IG), an algorithm was applied using fluids, dobutamine, and noradrenaline during the intraoperative period aiming at MAP > 65 mm Hg, SpO2 > 95%, CO2 gap < 6 mm Hg, and PPV < 13%. The control group (CG) comprised consecutive eligible patients who were operated by the same team before the institution of the algorithm. RESULTS: The rates of moderate and severe postoperative complications were lower in the IG (11% vs. 23%; IC: RR = 0.47, 95% CI: 0.246-0.929; P = 0.025). The respective 90- and 180-day mortality rates in the IG and CG were 9.8% vs. 22.5% (P = 0.014) and 12.6% vs. 25.5% (P = 0.020). CONCLUSIONS: An algorithm aiming to minimise the CO2 gap and normalise PPV was feasible and effective in decreasing rates of moderate and severe complications after surgery in high-risk patients.

Bundle of Coated Devices to Reduce Nosocomial Infections in the Intensive Care Unit. CRITIC Pilot Randomized Controlled Trial.

Rationale: Coated devices may reduce biofilm formation and reduce the occurrence of device-related infections in critically ill patients. A bundle of coated devices (an endotracheal tube [ETT], central venous catheter [CVC], and urinary catheter [UC]) simultaneously inserted may optimize benefits of coated devices in patients with the most severe illness.Objectives: To assess the feasibility of a randomized controlled trial on simultaneous insertion of gold/silver/palladium-coated devices versus uncoated devices in severely ill patients, which required sequential insertion of all three devices (an ETT, CVC, and UC) for support in the intensive care unit (ICU).Methods: This was a multicenter randomized controlled pilot trial. Patients who required simultaneous insertion of an ETT, CVC, and UC were randomized to treatment with coated versus uncoated devices, which were used as necessary for up to 28 days. The primary endpoint was feasibility, defined as the trial being able to enroll enough participants to have the sample size necessary for its secondary primary endpoint (estimating sepsis incidence in this population) in less than 1 year and for estimating the number of admitted patients who require simultaneous insertion of all three devices. Secondary endpoints included the incidence of sepsis and device-associated infections (ventilator-associated pneumonia, catheter-related bloodstream infection, and catheter-related urinary-tract infection) within each group as well as the number of days alive and free of antibiotics during the ICU stay. All events were adjudicated.Results: One hundred and three patients (48 in the coated-device group and 55 in the uncoated-device group) were included in the per-protocol analysis. The inclusion period was 8 months. There were 13 septic events in each group (26 in total), with an approximate incidence of sepsis of 32.3 (95% credible interval [CrI], 22.4-44.9) per 100 patient-days. The overall incidences of ventilator-associated pneumonia, catheter-related urinary-tract infection, and catheter-related bloodstream infection were 15.2 (95% CrI, 7.8-26.4), 6.3 (95% CrI, 2.4-13.7), and 7.9 (95% CrI, 3.6-15.1) per 1,000 patient-days, and incidence rates were not statistically different between groups. Patients in the coated-device group had more days alive and free of antibiotics in the ICU (28.97 d vs. 19.62 d per 100 patient-days; mean ratio, 1.48; 95% CrI, 1.16-1.89).Conclusions: Use of a bundle of coated devices as the initial treatment for of severely ill patients is feasible. Coated devices may be associated with more days alive and free of antibiotics.Clinical trial registered with www.clinicaltrials.gov (NCT03868241).

Excess mortality is associated with influenza A (H1N1) in patients with severe acute respiratory illness.

BACKGROUND: Acute respiratory infections caused by viruses are among the leading causes of morbidity and mortality. The inflammatory response that follows viral infection is important for the control of virus proliferation. However, if overwhelming, may be associated with complicated outcomes. OBJECTIVES: We assessed the clinical characteristics of patients with severe acute respiratory illness (SARI) evolving to acute respiratory distress syndrome (ARDS) and the factors related to death. STUDY DESIGN: Prospective study in 273 adult patients with SARI performed in a university-affiliated 800-bed hospital serving an area of epidemiologic vigilance of 102 municipalities and more than 2 million inhabitants. Influenza A (H1N1) 2009 (A/H1N1), influenza A H3N2, and influenza B were tested in all patients by RT-PCR. RESULTS: The overall hospital mortality rate was 17.6%. A total of 30.4% of patients tested positive for influenza A/H1N1. Patients with SARI that evolved to ARDS took significantly longer to take the first dose of oseltamivir (6.0 vs 1.0 days, p=0.002). Patients with H1N1 positive tests had almost 3 times higher probability of death, despite having significantly less comorbidities (p=0.027). The influenza A/H1N1 pdm09 vaccine reduced the odds of death by 78%. Nonsurvivors had a more intense inflammatory response than did survivors at 48 h (C-reactive protein: 31.0 ± 17.5 vs. 14.6 ± 8.9 mg/dl, p=0.001) as well as a more positive fluid balance. CONCLUSIONS: Hospital mortality associated with influenza H1N1-associated SARI and ARDS continued to be high years after the 2009 pandemic in a population with low vaccine coverage. Antiviral treatment started more than two days after onset of symptoms was more frequently associated with ARDS and death and, having had vaccine against influenza A (H1N1) was a factor independently related to survival.

Clinical review: What are the best hemodynamic targets for noncardiac surgical patients?

Perioperative hemodynamic optimization, or goal-directed therapy (GDT), has been show to significantly decrease complications and risk of death in high-risk patients undergoing noncardiac surgery. An important aim of GDT is to prevent an imbalance between oxygen delivery and oxygen consumption in order to avoid the development of multiple organ dysfunction. The utilization of cardiac output monitoring in the perioperative period has been shown to improve outcomes if integrated into a GDT strategy. GDT guided by dynamic predictors of fluid responsiveness or functional hemodynamics with minimally invasive cardiac output monitoring is suitable for the majority of patients undergoing major surgery with expected significant volume shifts due to bleeding or other significant intravascular volume losses. For patients at higher risk of complications and death, such as those with advanced age and limited cardiorespiratory reserve, the addition of dobutamine or dopexamine to the treatment algorithm, to maximize oxygen delivery, is associated with better outcomes.

Prospective, randomized trial comparing fluids and dobutamine optimization of oxygen delivery in high-risk surgical patients [ISRCTN42445141].

INTRODUCTION: Preventing perioperative tissue oxygen debt contributes to a better postoperative recovery. Whether the beneficial effects of fluids and inotropes during optimization of the oxygen delivery index (DO2I) in high-risk patients submitted to major surgeries are due to fluids, to inotropes, or to the combination of the two is not known. We aimed to investigate the effect of DO2I optimization with fluids or with fluids and dobutamine on the 60-day hospital mortality and incidence of complications. METHODS: A randomized and controlled trial was performed in 50 high-risk patients (elderly with coexistent pathologies) undergoing major elective surgery. Therapy consisted of pulmonary artery catheter-guided hemodynamic optimization during the operation and 24 hours postoperatively using either fluids alone (n = 25) or fluids and dobutamine (n = 25), aiming to achieve supranormal values (DO2I > 600 ml/minute/m2). RESULTS: The cardiovascular depression was an important component in the perioperative period in this group of patients. Cardiovascular complications in the postoperative period occurred significantly more frequently in the volume group (13/25, 52%) than in the dobutamine group (4/25, 16%) (relative risk, 3.25; 95% confidence interval, 1.22-8.60; P < 0.05). The 60-day mortality rates were 28% in the volume group and 8% in the dobutamine group (relative risk, 3.00; 95% confidence interval, 0.67-13.46; not significant). CONCLUSION: In patients with high risk of perioperative death, pulmonary artery catheter-guided hemodynamic optimization using dobutamine determines better outcomes, whereas fluids alone increase the incidence of postoperative complications.