|
Article 1
Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Adult Critically Ill Patient: Society of Critical Care Medicine (SCCM) and American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) McClave SA, Taylor BE, Martindale RG, Warren MM, Johnson DR, Braunschweig C, McCarthy MS, Davanos E, Rice TW, Cresci GA, Gervasio JM, Sacks GS, Roberts PR, Compher C. JPEN J Parenter Entetal Nutr. 2016 Feb;40(2):159-211.
This article is the periodic update to the nutritional support guidelines that are produced in a collaborative effort between the Society of Critical Care Medicine and the American Society for Parenteral and Enteral Nutrition. These guidelines are evidence-based and are updated every 3-5 years depending on the volume of relevant newly published literature. The assimilation of the literature is performed utilizing the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) process. These guidelines have incorporated data from publications up until December 31st, 2013.
The following is a summary of the recommendations: All patients admitted to an ICU should have a nutritional assessment. This assessment should take into account nutritional risk based on co-morbid conditions, GI track function, and risk of aspiration. Additionally, nutritional caloric and protein requirements should be calculated. Energy requirements can be determined with Indirect Calorimetry when available, otherwise simplistic calculations can be used (25-30kcal/kg/day). Ongoing assessment of adequate protein provisions should be performed and additional protein supplementation should be added if caloric goals are not being met secondary to frequent interruptions in enteral nutrition (EN).
Initiation of EN should be within 24−48 hours following the onset of critical illness and admission to the ICU. This is based on a large meta-analysis of studies comparing early vs delayed EN to mortality and infectious complications. EN is suggested over parenteral nutrition. Overt signs of GI contractility should not be required prior to initiation of EN and it is acceptable to initiate EN into the stomach in most patients. Patients at high risk of aspiration or those who have shown gastric EN intolerance should have their infusion diverted to the lower GI tract. Additional steps should be taken as needed to reduce the risk of aspiration and improve tolerance via the use of prokinetic agents, chlorhexidine mouthwashes, and elevation the head of bed (30-45 degrees).
Specific enteral feeding protocols with institution-specific strategies should be implemented to promote delivery of EN. This includes avoidance of inappropriate cessation of EN surrounding the time of diagnostic tests or procedures. Gastric residual volumes (GRV) should not be used as part of routine care to monitor ICU patients receiving EN. When GRV is utilized, holding EN for GRVs of less than 500cc should be avoided if there are no other signs of intolerance.
Finally, I strongly suggest readers consider looking through the guideline as there are specific recommendations for many of the surgical subset populations that we often care for such as TBI, open abdomens, burns, sepsis, pancreatitis, morbid obesity, liver failure, renal failure, etc.
Article 2
Effects of Aged Stored Autologous Red Blood Cells on Human Endothelial Function. Risbano MG, Kanias T, Triulzi D, Donadee C, Barge S, Badlam J, Jain S, Belanger AM, Kim-Shapiro DB, Gladwin MT. Am J Respir Crit Care Med. 2015 Nov 15;192(10):1223-33.
In this article, the authors studied the effects of autologous but aged blood on healthy volunteers. Their objective was to measure the effects of transfused blood at the FDA storage limit (6 weeks) on hemolysis and tissue perfusion. Hemolysis was measured by cell-free hemoglobin levels. Tissue perfusion was measured by forearm strain-gauge plethysmography during acetylcholine infusions. Acetylcholine is a Nitric Oxide (NO) synthase-dependent vasodilator. Hemolyzed RBCs scavenge NO secondary to release of cell-free hemoglobin and arginase-1. Thus the more hemolysis, the less available NO, and the less responsiveness to acetylcholine in the forearm will be seen.
Eighteen healthy volunteers participated by donating 500cc of blood. The blood was processed according to standard blood banking practice then cold stored. Half this blood was re-infused at day 5, and the other half at day 42. Assessments were taken at both time points. Ultimately, the results showed increased hemolysis in the 42 day group as compared to the 5 day group. Increased NO consumption and subsequent endothelial dysfunction was also noted secondary to abnormal forearm responses to the vasodilatory effects of acetylcholine.
This study is important and timely as two recent clinical trials have suggested that fresh blood has a similar safety profile to blood stored for 22-28 days (ABLE and RECESS trials). The current authors suggest that there may be safety concerns at the extreme of the FDA storage limit.
It should be noted that besides acute changes in endothelial function and hemolysis found in this study, there are other potential adverse effects of blood product transfusion that were not studied. This includes infectious and immunological effects. Despite these cautions however, blood transfusions can also be life-saving in certain circumstances. Thus, until there is a better substitute, appropriate blood banking techniques and triggers for transfusion must continue to be employed.
Article 3
Defining Transfusion Triggers and Utilization of Fresh Frozen Plasma and Platelets among Patients Undergoing Hepatopancreaticobiliary and Colorectal Surgery. Ejaz A, Frank SM, Spolverato G, Kim Y, Pawlik TM. Ann Surg. 2015 Dec;262(6):1079-85.
The authors of this study sought to evaluate their institution’s experience in transfusing FFP and platelets perioperatively in Hepatopancreaticobiliary and Colorectal surgery patients. They analyzed both triggers for transfusion and assessed overall perioperative outcomes as they related to the transfusions while controlling for other clinicopathologic data. Complications were determined by discharge ICD-9 codes.
Over a 13 year period at Johns Hopkins Hospital, 3027 cases were found for inclusion via retrospective review of their surgical database. Data was acquired from multiple institutional databases. Ultimately, the authors found 8.9% and 3.8% of all patients had received FFP and platelets, respectively. Nearly 50% of FFP transfusions were given in the face of INRs < 1.7. FFP and platelet transfusions were both found to be independently associated with worse outcomes on multivariate analysis including increased incidence of an extended length of stay, any complication including minor and major infectious complications, venous thromboembolism, respiratory complications, DIC, and in-hospital mortality.
Transfusion triggers continue to be a hotly debated topic secondary to clear risks and only proven benefits when levels are extremely low. RBC transfusions have reached some level of consensus (TRICC trail) but no such accord exists for FFP and platelets. Although this study does not scientifically define transfusion triggers utilizing a risk / benefit assessment, it does support the notion that transfusions can have adverse effects.
Article 4
VTE Incidence and Risk Factors in Patients with Severe Sepsis and Septic Shock. Kaplan D, Casper TC, Elliott CG, Men S, Pendleton RC, Kraiss LW, Weyrich AS, Grissom CK, Zimmerman GA, Rondina MT. Chest. 2015 Nov 1;148(5):1224-30.
In this study, the authors sought to evaluate the incidence of venothrombotic events (VTE) in patients with severe sepsis and septic shock. The study was performed in a prospective observational fashion at three ICUs associated with the University of Utah and Intermountain medical center. Inclusion criteria included strictly defined severe sepsis and septic shock. Appropriate exclusions were also used. All patients received “standard of care” thrombo-prophylaxis for VTE events during their ICU stay. Screening compression ultrasounds were performed upon ICU discharge and if clinically indicated.
113 consecutive patients were enrolled. The overall VTE rate was 37.2% and most were clinically significant and not just “incidental findings”. VTE events were associated with an increased length of stay and approached significance for mortality. Insertion of a central line and mechanical ventilation were significant independent risk factors on multivariate analysis. VTE events did not differ by thrombo-prophylaxis type (unfractionated heparin vs low molecular weight heparin).
Take home points: despite following guideline-based thrombo-prophylaxis, a significant amount of patients with severe sepsis and septic shock will develop clinically significant VTE events. This finding is even more profound when central lines or mechanical ventilation is used. Thus, additional strategies may be warranted to discontinue central lines and ready for extubation at earlier time points. Further, additional studies are needed to optimize current thrombo-prophylaxis dosing.
|