Fully automated postoperative ventilation in cardiac surgery patients: a randomised clinical trial.

BACKGROUND: Ensuring that lung-protective ventilation is achieved at scale is challenging in perioperative practice. Fully automated ventilation may be more effective in delivering lung-protective ventilation. Here, we compared automated lung-protective ventilation with conventional ventilation after elective cardiac surgery in haemodynamically stable patients. METHODS: In this single-centre investigator-led study, patients were randomly assigned at the end of cardiac surgery to receive either automated (adaptive support ventilation) or conventional ventilation. The primary endpoint was the proportion of postoperative ventilation time characterised by exposure to predefined optimal, acceptable, and critical (injurious) ventilatory parameters in the first three postoperative hours. Secondary outcomes included severe hypoxaemia (Spo2 <85%) and resumption of spontaneous breathing. Data are presented as mean (95% confidence intervals [CIs]). RESULTS: We randomised 220 patients (30.4% females; age: 62-76 yr). Subjects randomised to automated ventilation (n=109) spent a 29.7% (95% CI: 22.1-37.4) higher mean proportion of postoperative ventilation time receiving optimal postoperative ventilation after surgery (P<0.001) compared with subjects receiving conventional postoperative ventilation (n=111). Automated ventilation also reduced the proportion of postoperative ventilation time that subjects were exposed to injurious ventilatory settings by 2.5% (95% CI: 1-4; P=0.003). Severe hypoxaemia was less likely in subjects randomised to automated ventilation (risk ratio: 0.26 [0.22-0.31]; P<0.01). Subjects resumed spontaneous breathing more rapidly when randomised to automated ventilation (hazard ratio: 1.38 [1.05-1.83]; P=0.03). CONCLUSIONS: Fully automated ventilation in haemodynamically stable patients after cardiac surgery optimised lung-protective ventilation during postoperative ventilation, with fewer episodes of severe hypoxaemia and an accelerated resumption of spontaneous breathing. CLINICAL TRIAL REGISTRATION: NCT03180203.

Beneficial Effects of Early Enteral Nutrition After Major Rectal Surgery: A Possible Role for Conditionally Essential Amino Acids? Results of a Randomized Clinical Trial.

OBJECTIVES: To investigate direct postoperative outcome and plasma amino acid concentrations in a study comparing early enteral nutrition versus early parenteral nutrition after major rectal surgery. Previously, it was shown that a low plasma glutamine concentration represents poor prognosis in ICU patients. DESIGN: A preplanned substudy of a previous prospective, randomized, open-label, single-centre study, comparing early enteral nutrition versus early parenteral nutrition in patients at high risk of postoperative ileus after surgery for locally advanced or locally recurrent rectal cancer. Early enteral nutrition reduced postoperative ileus, anastomotic leakage, and hospital stay. SETTING: Tertiary referral centre for locally advanced and recurrent rectal cancer. PATIENTS: A total of 123 patients with locally advanced or recurrent rectal carcinoma requiring major rectal surgery. INTERVENTIONS: Patients were randomized (ALEA web-based external randomization) preoperatively into two groups: early enteral nutrition (early enteral nutrition, intervention) by nasojejunal tube (n = 61) or early parenteral nutrition (early parenteral nutrition, control) by jugular vein catheter (n = 62). Eight hours after the surgical procedure artificial nutrition was started in hemodynamically stable patients, stimulating oral intake in both groups. Blood samples were collected to measure plasma glutamine, citrulline, and arginine concentrations using a validated ultra performance liquid chromatography-tandem mass spectrometric method. MEASUREMENTS AND MAIN RESULTS: Baseline concentrations were comparable for both groups. Directly after rectal surgery, a decrease in plasma amino acids was observed. Plasma glutamine concentrations were higher in the parenteral group than in the enteral group on postoperative day 1 (p = 0.027) and day 5 (p = 0.008). Arginine concentrations were also significantly increased in the parenteral group at day 1 (p < 0.001) and day 5 (p = 0.001). CONCLUSIONS: Lower plasma glutamine and arginine concentrations were measured in the enteral group, whereas a better clinical outcome was observed. We conclude that plasma amino acids do not provide a causal explanation for the observed beneficial effects of early enteral feeding after major rectal surgery.

Reduction of postoperative ileus by early enteral nutrition in patients undergoing major rectal surgery: prospective, randomized, controlled trial.

BACKGROUND: The current trend in postoperative nutrition is to promote a normal oral diet as early as possible. However, postoperative ileus is a frequent and common problem after major abdominal surgery. This study was designed to investigate whether early enteral nutrition (EEN), as a bridge to a normal diet, can reduce postoperative ileus. METHODS: Patients undergoing major rectal surgery for locally advanced primary or recurrent rectal carcinoma (after neoadjuvant (chemo)-radiation, with or without intraoperative radiotherapy) were randomly assigned to EEN (n = 61) or early parenteral nutrition (EPN, n = 62) in addition to an oral diet. Early nutrition was started 8 hours after surgery. Early parenteral nutrition was given as control nutrition to obtain caloric equivalence and minimize confounding. The primary endpoint was time to first defecation; secondary outcomes were morbidity, other ileus symptoms, and length of hospital stay. RESULTS: Baseline characteristics were similar for both groups. In intention-to-treat analysis, the time to first defecation was significantly shorter in the enteral nutrition arm than in the control arm (P = 0.04). Moreover, anastomotic leakage occurred significantly less frequently in the enteral group (1 patient) compared with parenteral supplementation (9 patients, P = 0.009). Mean length of stay in the enteral group was 13.4 ± 2.2 days versus 16.7 ± 2.3 days in the parenteral group (P = 0.007). CONCLUSIONS: Early enteral nutrition is safe and associated with significantly less ileus. Early enteral nutrition is associated with less anastomotic leakage in patients undergoing extensive rectal surgery.

Treatment of hypophosphatemia in the intensive care unit: a review.

INTRODUCTION: Currently no evidence-based guideline exists for the approach to hypophosphatemia in critically ill patients. METHODS: We performed a narrative review of the medical literature to identify the incidence, symptoms, and treatment of hypophosphatemia in critically ill patients. Specifically, we searched for answers to the questions whether correction of hypophosphatemia is associated with improved outcome, and whether a certain treatment strategy is superior. RESULTS: Incidence: hypophosphatemia is frequently encountered in the intensive care unit; and critically ill patients are at increased risk for developing hypophosphatemia due to the presence of multiple causal factors. SYMPTOMS: hypophosphatemia may lead to a multitude of symptoms, including cardiac and respiratory failure. TREATMENT: hypophosphatemia is generally corrected when it is symptomatic or severe. However, although multiple studies confirm the efficacy and safety of intravenous phosphate administration, it remains uncertain when and how to correct hypophosphatemia. OUTCOME: in some studies, hypophosphatemia was associated with higher mortality; a paucity of randomized controlled evidence exists for whether correction of hypophosphatemia improves the outcome in critically ill patients. CONCLUSIONS: Additional studies addressing the current approach to hypophosphatemia in critically ill patients are required. Studies should focus on the association between hypophosphatemia and morbidity and/or mortality, as well as the effect of correction of this electrolyte disorder.

Clinical outcome of immunonutrition in a heterogeneous intensive care population.

OBJECTIVE: To study the effect of a high-protein enteral formula enriched with arginine, glutamine, and antioxidants and containing omega3 fatty acids and a mixture of fibers, on the clinical outcome of a heterogeneous intensive care (ICU) population. DESIGN AND SETTING: A randomized, prospective, double blind, controlled, two-center clinical trial in two intensive care units in The Netherlands. PATIENTS AND PARTICIPANTS: A total of 597 adult ICU patients expected to require enteral tube feeding for more than 2 days were randomized to receive immunonutrition or an isocaloric control formula. INTERVENTIONS: Patients received either the immunonutrition or the control feed. MEASUREMENTS AND RESULTS: Intention-to-treat and per-protocol analyses showed no statistically significant difference in clinical outcome parameters between the two groups. Results of the intention-to-treat analysis in control vs. immunonutrition were: median ICU length of stay in days, 8.0 (IQR 5.0-16.0) vs. 7.0 (4.0-14.0); median hospital length of stay in days, 20.0 (IQR 10.0-34.0) vs. 20.0 (10.0-35.0); median days of ventilation, 6.0 (IQR 3.0-12.0) vs. 6.0 (IQR 3.0-12.0); ICU mortality, 26.8% vs. 28.2%; in-hospital mortality, 36.4% vs. 38.5%; infectious complications, 41.7% vs. 43.0%. CONCLUSIONS: The results of this largest randomized, controlled trial found that in the general ICU population immunonutrition has no beneficial effect on clinical outcome parameters. These results are consistent with the literature that is currently available.