Colloids versus crystalloids for fluid resuscitation in critically ill patients

Development and In Silico Evaluation of a Model-Based Closed-Loop Fluid Resuscitation Control Algorithm

OBJECTIVE

To develop and evaluate in silico a model-based closed-loop fluid resuscitation control algorithm via blood volume feedback.

METHODS

Model-based adaptive control algorithm for fluid resuscitation was developed by leveraging a low-order lumped-parameter blood volume dynamics model, and then in silico evaluated based on a detailed mechanistic model of circulatory physiology. The algorithm operates in two steps: (1) the blood volume dynamics model is individualized based on the patient's fractional blood volume response to an initial fluid bolus via system identification; and (2) an adaptive control law built on the individualized blood volume dynamics model regulates the blood volume of the patient.

RESULTS

The algorithm was able to track the blood volume set point as well as accurately estimate and monitor the patient's absolute blood volume level. The algorithm significantly outperformed a population-based proportional-integral-derivative control.

CONCLUSION

Model-based development of closed-loop fluid resuscitation control algorithm may enable regulation of blood volume and monitoring of absolute blood volume level.

SIGNIFICANCE

Model-based closed-loop fluid resuscitation algorithm may offer opportunities for standardized and patient-tailored therapy and reduction of clinician workload.

Translational Research for Acute Pancreatitis - Which Results Have Really Influenced Our Therapy?

Acute pancreatitis is a common disease characterized by acinar cell destruction and acute inflammatory changes of the pancreas that lead to a systemic inflammatory response. A major research effort has been undertaken to unravel the underlying pathophysiology and to identify possible therapeutic targets. Still, only very few findings have influenced our clinical practice in the treatment of acute pancreatitis. Pancreatic microcirculation and capillary blood flow have long been suspected to play a major role in the course of the disease. It therefore seemed tempting to speculate that manipulation of the vasoconstrictor endothelin or its antagonist nitrogen monoxide could positively influence the outcome. We had to acknowledge, however, that these mechanisms take place very early in the disease course and that only prophylactic applications show an effect; this is useful in the setting of pancreas transplantation and endoscopic retrograde cholangiopancreatography but not applicable for clinical use in the therapy of acute pancreatitis. Research then focused on later pathophysiological stages of the disease, mainly on the process of adhesion and extravasation of leukocytes into the pancreatic tissue. Here, integrins and adhesion molecules like the intercellular adhesion molecule-1 (ICAM-1) were investigated in detail. A monoclonal antibody to ICAM-1 showed promising results in experimental models but was never further evaluated in the clinical setting. Hemodilution and fluid resuscitation was recognized to be an important therapeutic tool in acute pancreatitis. Here, initial experimental studies favored colloid solutions, and especially dextrans for isovolemic fluid resuscitation. It was recognized only later that colloid solutions are not effective and may even increase mortality in critically ill patients. Therefore, goal-directed infusion of Ringer's lactate solution at a moderate infusion rate to optimize volume status and hemoconcentration in acute pancreatitis is now advocated. In summary, out of the numerous experimental and translational studies, only very few have really influenced our daily clinical practice. Further research is therefore needed to find more specific and effective therapeutic agents for the treatment of acute pancreatitis.

Goal-directed fluid therapy in urgent GAstrointestinal Surgery-study protocol for A Randomised multicentre Trial: The GAS-ART trial

INTRODUCTION

Intravenous fluid therapy during gastrointestinal surgery is a life-saving part of the perioperative care. Too little fluid may lead to hypovolaemia, decreased organ perfusion and circulatory shock. Excessive fluid administration increases postoperative complications, worsens pulmonary and cardiac function as well as the healing of surgical wounds. Intraoperative individualised goal-directed fluid therapy (GDT) and zero-balance therapy (weight adjusted) has shown to reduce postoperative complications in elective surgery, but studies in urgent gastrointestinal surgery are sparse. The aim of the trial is to test whether zero-balance GDT reduces postoperative mortality and major complications following urgent surgery for obstructive bowel disease or perforation of the gastrointestinal tract compared with a protocolled standard of care.

METHODS/ANALYSIS

This study is a multicentre, randomised controlled trial with planned inclusion of 310 patients. The randomisation procedure is stratified by hospital and by obstructive bowel disease and perforation of the gastrointestinal tract. Patients are allocated into either 'the standard group' or 'the zero-balance GDT group'. The latter receive intraoperative GDT (guided by a stroke volume algorithm) and postoperative zero-balance fluid therapy based on body weight and fluid charts. The protocolled treatment continues until free oral intake or the seventh postoperative day.The primary composite outcome is death, unplanned reoperations, life-threatening thromboembolic and bleeding complications, a need for mechanical ventilation or dialysis. Secondary outcomes are additional complications, length of hospital stay, length of stay in the intensive care unit, length of mechanical ventilation, readmissions and time to death. Follow-up is 90 days.We plan intention-to-treat analysis of the primary outcome.

ETHICS AND DISSEMINATION

The Danish Scientific Ethics Committee approved the GAS-ART trial before patient enrolment (J: SJ-436). Enrolment of patients began in August 2015 and is proceeding. We expect to publish the GAS-ART results in Summer 2019.

TRIAL REGISTRATION NUMBER

EudraCT 2015-000563-14.

Fluid resuscitation in critically ill patients: a systematic review and network meta-analysis

Objective

The aim of this study was to compare the effectiveness of different fluids on critically ill patients who need fluid resuscitation through a systematic review and network meta-analysis (NMA).

Data sources

Electronic databases were searched up to March 2018 for randomized controlled trials comparing the effectiveness of different fluids in critically ill patients. The primary outcome was mortality, and the secondary outcomes were the incident of acute kidney injury (AKI) and risk of receiving renal replacement therapy (RRT). A Bayesian NMA was conducted, and the quality of evidence contributing to each network estimate was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group criteria.

Results

We deemed 49 trials eligible, including 40,910 participants. The quality of evidence was rated as moderate in most comparisons. There was no significant difference among resuscitation fluids in mortality. NMA at the 9-node level showed the most effective fluid was balanced crystalloid (BC) (80.79%, the ranking of resuscitation fluid based on cumulative probability plots and surface under the cumulative ranking curves [SUCRAs]). NMA at the 10-node level showed that the most effective fluid was Plasma-Lyte (77.52%). Results of sensitivity analyses in mortality did not reveal any significant changes in the findings for primary outcomes. High-molecular-weight hetastarch (H-HES) was associated with an increased incidence of AKI when compared with gelatin (odds ratio [OR], 0.43; 95% credibility interval [CrI], 0.19–0.94), low-molecular-weight hetastarch (L-HES; OR, 0.50; 95% CrI, 0.30–0.87), BC (OR, 0.55; 95% CrI, 0.34–0.88), and normal saline (OR, 0.56; 95% CrI, 0.34–0.93). Meanwhile, H-HES was also associated with an increased risk of receiving RRT when compared with BC (OR, 0.51; 95% CrI, 0.27–0.93) and normal saline (OR, 0.52; 95% CrI, 0.24–0.96).

Conclusion

BCs, especially the Plasma-Lyte, are presumably the best choice for most critically ill patients who need fluid resuscitation. Meanwhile, the use of H-HES was associated with an increased incidence of AKI and risk of receiving RRT.

Registration

PROSPERO (CRD42017072728).

Comparison of dextran and albumin on blood coagulation in patients undergoing major gynaecological surgery

Background

Hydroxyethyl starches have been withdrawn from the European market. In Sweden, dextran was the main colloid until 2000, when starches overtook the market. After the recent 6S-trial, it was suggested that dextran could be reinstituted, but concerns for greater coagulopathy, bleeding and anaphylaxis still remain. An experimental study from our department indicated that isovolemic substitution of dextran-70 did not derange the von Willebrand function more than albumin 5%, considering the fact that dextran is hyperoncotic in comparison to albumin 5% and, therefore, induces a greater plasma volume expansion and thereby a greater dilutional coagulopathy.

Methods

Eighteen patients undergoing major gynaecological surgery were assigned to receive either 5% albumin or 6% dextran-70 with 9 patients in each group. Standard coagulation tests, including prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and platelet count, viscoelastic coagulation test thromboelastometry (ROTEM) and the Multiplate platelet aggregation test were used to test for coagulation defects at different time points perioperatively. Blood loss, blood loss replacement data and haemodynamic parameters were retrieved from anaesthetic and postoperative charts. A local departmental fluid and transfusion/infusion protocol assured haemoglobin > 90 g/l and mean arterial pressure > 65 mmHg with Ringer’s acetate in addition to the colloid use.

Results

There were no differences in demographic data between the groups. The tissue factor-activated (EXTEM) clot-structure parameter ROTEM A10 was decreased significantly in the dextran group as compared to the albumin group after the infusion of 500 ml of either colloid solution. The PT and aPTT were significantly prolonged, and the platelet count decreased postoperatively in the dextran group, whereas albumin only deranged fibrinogen levels as compared to preoperative levels. There were no differences in Multiplate platelet aggregometry, amount of haemorrhage or transfusion of blood components between the groups.

Conclusions

Standard plasma-based coagulation tests, platelet count and whole blood viscoelastic clot structure are affected by 6% dextran-70 to a greater extent than by 5% albumin, but platelet aggregation is not. Future studies should use more advanced haemodynamic monitoring to assess isovolemic plasma volume expansion with dextran and whether this affects haemostasis to a lesser degree.

Colloids versus crystalloids for fluid resuscitation in critically ill people

BACKGROUND

Critically ill people may lose fluid because of serious conditions, infections (e.g. sepsis), trauma, or burns, and need additional fluids urgently to prevent dehydration or kidney failure. Colloid or crystalloid solutions may be used for this purpose. Crystalloids have small molecules, are cheap, easy to use, and provide immediate fluid resuscitation, but may increase oedema. Colloids have larger molecules, cost more, and may provide swifter volume expansion in the intravascular space, but may induce allergic reactions, blood clotting disorders, and kidney failure. This is an update of a Cochrane Review last published in 2013.

OBJECTIVES

To assess the effect of using colloids versus crystalloids in critically ill people requiring fluid volume replacement on mortality, need for blood transfusion or renal replacement therapy (RRT), and adverse events (specifically: allergic reactions, itching, rashes).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and two other databases on 23 February 2018. We also searched clinical trials registers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs of critically ill people who required fluid volume replacement in hospital or emergency out-of-hospital settings. Participants had trauma, burns, or medical conditions such as sepsis. We excluded neonates, elective surgery and caesarean section. We compared a colloid (suspended in any crystalloid solution) versus a crystalloid (isotonic or hypertonic).

DATA COLLECTION AND ANALYSIS

Independently, two review authors assessed studies for inclusion, extracted data, assessed risk of bias, and synthesised findings. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We included 69 studies (65 RCTs, 4 quasi-RCTs) with 30,020 participants. Twenty-eight studied starch solutions, 20 dextrans, seven gelatins, and 22 albumin or fresh frozen plasma (FFP); each type of colloid was compared to crystalloids.Participants had a range of conditions typical of critical illness. Ten studies were in out-of-hospital settings. We noted risk of selection bias in some studies, and, as most studies were not prospectively registered, risk of selective outcome reporting. Fourteen studies included participants in the crystalloid group who received or may have received colloids, which might have influenced results.We compared four types of colloid (i.e. starches; dextrans; gelatins; and albumin or FFP) versus crystalloids.Starches versus crystalloidsWe found moderate-certainty evidence that there is probably little or no difference between using starches or crystalloids in mortality at: end of follow-up (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.86 to 1.09; 11,177 participants; 24 studies); within 90 days (RR 1.01, 95% CI 0.90 to 1.14; 10,415 participants; 15 studies); or within 30 days (RR 0.99, 95% CI 0.90 to 1.09; 10,135 participants; 11 studies).We found moderate-certainty evidence that starches probably slightly increase the need for blood transfusion (RR 1.19, 95% CI 1.02 to 1.39; 1917 participants; 8 studies), and RRT (RR 1.30, 95% CI 1.14 to 1.48; 8527 participants; 9 studies). Very low-certainty evidence means we are uncertain whether either fluid affected adverse events: we found little or no difference in allergic reactions (RR 2.59, 95% CI 0.27 to 24.91; 7757 participants; 3 studies), fewer incidences of itching with crystalloids (RR 1.38, 95% CI 1.05 to 1.82; 6946 participants; 2 studies), and fewer incidences of rashes with crystalloids (RR 1.61, 95% CI 0.90 to 2.89; 7007 participants; 2 studies).Dextrans versus crystalloidsWe found moderate-certainty evidence that there is probably little or no difference between using dextrans or crystalloids in mortality at: end of follow-up (RR 0.99, 95% CI 0.88 to 1.11; 4736 participants; 19 studies); or within 90 days or 30 days (RR 0.99, 95% CI 0.87 to 1.12; 3353 participants; 10 studies). We are uncertain whether dextrans or crystalloids reduce the need for blood transfusion, as we found little or no difference in blood transfusions (RR 0.92, 95% CI 0.77 to 1.10; 1272 participants, 3 studies; very low-certainty evidence). We found little or no difference in allergic reactions (RR 6.00, 95% CI 0.25 to 144.93; 739 participants; 4 studies; very low-certainty evidence). No studies measured RRT.Gelatins versus crystalloidsWe found low-certainty evidence that there may be little or no difference between gelatins or crystalloids in mortality: at end of follow-up (RR 0.89, 95% CI 0.74 to 1.08; 1698 participants; 6 studies); within 90 days (RR 0.89, 95% CI 0.73 to 1.09; 1388 participants; 1 study); or within 30 days (RR 0.92, 95% CI 0.74 to 1.16; 1388 participants; 1 study). Evidence for blood transfusion was very low certainty (3 studies), with a low event rate or data not reported by intervention. Data for RRT were not reported separately for gelatins (1 study). We found little or no difference between groups in allergic reactions (very low-certainty evidence).Albumin or FFP versus crystalloidsWe found moderate-certainty evidence that there is probably little or no difference between using albumin or FFP or using crystalloids in mortality at: end of follow-up (RR 0.98, 95% CI 0.92 to 1.06; 13,047 participants; 20 studies); within 90 days (RR 0.98, 95% CI 0.92 to 1.04; 12,492 participants; 10 studies); or within 30 days (RR 0.99, 95% CI 0.93 to 1.06; 12,506 participants; 10 studies). We are uncertain whether either fluid type reduces need for blood transfusion (RR 1.31, 95% CI 0.95 to 1.80; 290 participants; 3 studies; very low-certainty evidence). Using albumin or FFP versus crystalloids may make little or no difference to the need for RRT (RR 1.11, 95% CI 0.96 to 1.27; 3028 participants; 2 studies; very low-certainty evidence), or in allergic reactions (RR 0.75, 95% CI 0.17 to 3.33; 2097 participants, 1 study; very low-certainty evidence).

AUTHORS' CONCLUSIONS

Using starches, dextrans, albumin or FFP (moderate-certainty evidence), or gelatins (low-certainty evidence), versus crystalloids probably makes little or no difference to mortality. Starches probably slightly increase the need for blood transfusion and RRT (moderate-certainty evidence), and albumin or FFP may make little or no difference to the need for renal replacement therapy (low-certainty evidence). Evidence for blood transfusions for dextrans, and albumin or FFP, is uncertain. Similarly, evidence for adverse events is uncertain. Certainty of evidence may improve with inclusion of three ongoing studies and seven studies awaiting classification, in future updates.

Resuscitation with centhaquin and 6% hydroxyethyl starch 130/0.4 improves survival in a swine model of hemorrhagic shock: a randomized experimental study

PURPOSE

To investigate the effects of the combination of centhaquin and 6% hydroxyethyl starch 130/0.4 (HES 130/0.4) in a swine model of hemorrhagic shock.

METHODS

Twenty Landrace-Large White pigs were instrumented and subjected to hemorrhagic shock. The animals were randomly allocated in two experimental groups, the control (group CO, n = 10) and the centhaquin groups (0.015 mg/kg, n = 10, group CH). Acute hemorrhage was induced by stepwise blood withdrawal (18 mL/min) from the internal jugular vein until MAP decreased to 40-45 mmHg, whereas anesthesia remained constant. All animals received HES 130/0.4 solution in the resuscitation phase until their mean arterial pressure (MAP) reached 90% of the baseline. The animals were observed for 60 min, during which no further resuscitation was attempted.

RESULTS

The total amount of blood and the bleeding time did not differ significantly between group CO and group CH (120 ± 13 vs. 120 ± 14 mL, p = 0.6; 20 ± 2 vs. 20 ± 1 min, p = 0.62, respectively). During the hemorrhagic phase, only a difference in heart rate (97.6 ± 4.4 vs. 128.4 ± 3.6 beats/min, p = 0.038) was observed between the two groups. The time required to reach the target MAP was significantly shorter in the centhaquin group compared to controls (13.7 ± 0.4 vs. 19.6 ± 0.84 min, p = 0.012). During the resuscitation phase, a statistical significant difference was observed in MAP (75.2 ± 1.6 vs. 89.8 ± 2.1 mmHg, p = 0.02) between group CO and group CH. During the observation phase, a statistical significant difference was observed in SVR (1109 ± 32.65 vs. 774.6 ± 21.82 dyn s/cm⁵, p = 0.039) and cardiac output (5.82 ± 0.31 vs. 6.9 ± 0.78 L/min, p = 0.027) between the two groups. Two animals of group CO and seven animals of group CH survived for 24 h (p = 0.008). We observed a marked increase in microvascular capillary permeability in group CO compared to group CH, with the wet/dry weight ratio being significantly higher in group CO compared to group CH (4.8 ± 1.6 vs. 3.08 ± 0.6, p < 0.001).

CONCLUSIONS

The combination of centhaquin 0.015 mg/kg and HES 130/0.4 resulted in shorter time to target MAP, lower wet-to-dry ratio, and better survival rates after resuscitation from hemorrhagic shock.

Fluid therapy in the emergency department: an expert practice review

Intravenous fluid therapy is one of the most common therapeutic interventions performed in the ED and is a long-established treatment. The potential benefits of fluid therapy were initially described by Dr W B O’Shaughnessy in 1831 and first administered to an elderly woman with cholera by Dr Thomas Latta in 1832, with a marked initial clinical response. However, it was not until the end of the 19th century that medicine had gained understanding of infection risk that practice became safer and that the practice gained acceptance. The majority of fluid research has been performed on patients with critical illness, most commonly sepsis as this accounts for around two-thirds of shocked patients treated in the ED. However, there are few data to guide clinicians on fluid therapy choices in the non-critically unwell, by far our largest patient group. In this paper, we will discuss the best evidence and controversies for fluid therapy in medically ill patients.

Predictors of major complications after elective abdominal surgery in cancer patients

Background

Patients undergoing abdominal surgery for solid tumours frequently develop major postoperative complications, which negatively affect quality of life, costs of care and survival. Few studies have identified the determinants of perioperative complications in this group.

Methods

We performed a prospective observational study including all patients (age > 18) undergoing abdominal surgery for cancer at a single institution between June 2011 and August 2013. Patients undergoing emergency surgery, palliative procedures, or participating in other studies were excluded. Primary outcome was a composite of 30-day all-cause mortality and infectious, cardiovascular, respiratory, neurologic, renal and surgical complications. Univariate and multiple logistic regression analyses were performed to identify predictive factors for major perioperative adverse events.

Results

Of a total 308 included patients, 106 (34.4%) developed a major complication during the 30-day follow-up period. Independent predictors of postoperative major complications were: age (odds ratio [OR] 1.03 [95% CI 1.01–1.06], p = 0.012 per year), ASA (American Society of Anesthesiologists) physical status greater than or equal to 3 (OR 2.61 [95% CI 1.33–5.17], p = 0.003), a preoperative haemoglobin level lower than 12 g/dL (OR 2.13 [95% CI 1.21–4.07], p = 0.014), intraoperative use of colloids (OR 1.89, [95% CI 1.03–4.07], p = 0.047), total amount of intravenous fluids (OR 1.22 [95% CI 0.98–1.59], p = 0.106 per litre), intraoperative blood losses greater than 500 mL (2.07 [95% CI 1.00–4.31], p = 0.043), and hypotension needing vasopressor support (OR 4.68 [95% CI 1.55–27.72], p = 0.004). The model had good discrimination with the area under the ROC curve being 0.80 (95% CI 0.75–0.84, p < 0.001).

Conclusions

Our findings suggest that a perioperative strategy aimed at reducing perioperative complications in cancer surgery should include treatment of preoperative anaemia and an optimal fluid strategy, avoiding fluid overload and intraoperative use of colloids.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0516-6) contains supplementary material, which is available to authorized users.

Association of Total Fluid Intake and Output with Duration of Hospital Stay in Patients with Acute Pancreatitis

Background/Aims

The aim of this study was to evaluate the association of fluid balance with outcomes in patients hospitalized with acute pancreatitis (AP).

Methods

This was a retrospective study of patients hospitalized between May 2008 and June 2016 with AP and a clinical order for strict recording of intake and output. Data collected included various types of fluid intake and output at 24 and 48 hours after admission. The primary outcome was length of stay (LOS). Analysis was performed using single-variable and multivariable negative binomial regression models.

Results

Of 1256 patients hospitalized for AP during the study period, only 71 patients (5.6%) had a clinical order for strict recording of intake and output. Increased urine output was associated with a decreased LOS at 24 and 48 hours in univariable analysis. An increasingly positive fluid balance (total intake minus urine output) at 24 hours was associated with a longer LOS in multivariable analysis.

Conclusions

Few patients hospitalized for AP had a documented order for strict monitoring of fluid intake and output, despite the importance of monitoring fluid balance in these patients. Our study suggests an association between urine output and fluid balance with LOS in AP.

Singapore Paediatric Resuscitation Guidelines 2016

We present the revised 2016 Singapore paediatric resuscitation guidelines. The International Liaison Committee on Resuscitation's Pediatric Taskforce Consensus Statements on Science and Treatment Recommendations, as well as the updated resuscitation guidelines from the American Heart Association and European Resuscitation Council released in October 2015, were debated and discussed by the workgroup. The final recommendations for the Singapore Paediatric Resuscitation Guidelines 2016 were derived after carefully reviewing the current available evidence in the literature and balancing it with local clinical practice.

Inaction over retractions of identified fraudulent publications: ongoing weakness in the system of scientific self-correction

Published articles may be retracted when their findings are no longer considered reliable due to honest error, publication misconduct, or research misconduct. This article focuses on the case of a single serial violator of research and publication ethics in anesthesiology and critical care, which is widely publicized. A chain of events led to detection of misconduct that had substantial impact on the evidence base for the safety of hydroxyethyl starch, an intravenous artificial colloid solution, which is reflected in current guidelines on fluid management and volume resuscitation. As citations to retracted works continue to be a cause for concern, this article reviews the retraction status of this author's published articles to determine whether sufficient action has been taken to retract his body of work. Results show that retraction practices are not uniform and that guidelines for retraction are still not being fully implemented, resulting in retractions of insufficient quantity and quality. As retractions continue to emerge for the author's publications, with ten more since 2011, and as they are generally increasing, these data on retractions not only provide findings of misconduct, but also allow us to make inferences about ongoing weaknesses in the system of scientific literature.

The effects of crystalloid versus synthetic colloid in vitro on immune cells, co-cultured with mouse splenocytes

This study assessed the effects of crystalloid versus synthetic colloid in vitro on immune cells co-cultured with mouse splenocytes. Mouse splenocytes were co-cultured with three different types of fluid: Plasma solution-A^® (CJ HealthCare, Seoul, Korea; the crystalloid group); Tetraspan 6%^® (B. Braun Medical, Melsungen, Germany; the Colloid-T group); and Volulyte 6%^® (Fresenius Kabi, Bad Homburg vor dér-Höhe, Germany; Colloid-V group). To evaluate the acquired immune response, cluster of differentiation (CD) 4⁺ T cells and CD8⁺ T cells were measured. To evaluate the innate immune response, neutrophils were measured. The frequencies of CD4⁺ and CD8⁺ T cells did not differ significantly among the three groups on day 1 or 3. However, the frequencies of CD4⁺ and CD8⁺ T cells in the two synthetic colloid groups were significantly higher than those in the crystalloid group on day 7. On day 1, the frequency of neutrophils was significantly lower in the two synthetic colloid groups, compared with the crystalloid group. However, the values on the other days were similar among all three groups. In conclusion, crystalloid had a limited effect on the immune response; on the other hand, synthetic colloid increased the acquired immune response, although it temporarily inhibited the innate immune response.

Evaluation and management of Non-variceal upper gastrointestinal bleeding

Non-variceal upper gastrointestinal bleeding continues to be an important cause of morbidity and mortality. The most common causes include peptic ulcer disease, Mallory-Weiss syndrome, erosive gastritis, duodenitis, esophagitis, malignancy, angiodysplasias and Dieulafoy's lesion. Initial assessment and early aggressive resuscitation significantly improves outcomes. Upper gastrointestinal endoscopy continues to be the gold standard for diagnosis and treatment. We present a comprehensive review of literature for the evaluation and management of non-variceal upper gastrointestinal bleeding.

[Hemorrhagic shock : General principles]

Bleeding associated with hemorrhagic shock is often seen in emergency medical services or in the intensive care unit. Identifying the origin of the bleeding and additional disorders helps to determine the degree of the hemorrhagic shock. In order to be effective, the initial therapy until blood products are available needs to be differentiated to be effective in terms of hemodynamic stabilization and coagulation. Crystalloidal and colloidal solutions should be used carefully since those solutions bear a risk within themselves. Treatment of acidosis and hypothermia can further reduce bleeding complications. Early and repeated monitoring of clotting should be performed simultaneously to shock therapy to permit specific treatment and substitution of coagulation factors if needed. Hemorrhagic shock therapy should be continued until bleeding is stopped.

Hydroxyethyl starch for volume expansion after subarachnoid haemorrhage and renal function: Results of a retrospective analysis

BACKGROUND

Hydroxyethyl starch (HES) was part of "triple-H" therapy for prophylaxis and therapy of vasospasm in patients with subarachnoid haemorrhage (SAH). The European Medicines Agency restricted the use of HES in 2013 due to an increase of renal failure in critically ill patients receiving HES compared to crystalloid fluids. The occurrence of renal insufficiency in patients with SAH due to HES is still uncertain. The purpose of our study was to evaluate whether there was an association with renal impairment in patients receiving HES after subarachnoid haemorrhage.

METHODS

Medical records of all non-traumatic SAH patients treated at the Departments of Anaesthesiology and Neurosurgery, University Hospital of Leipzig, Germany, between January 2009 and December 2014 were analysed. Patients received either HES 6% and/or 10% (HES group, n = 183) or exclusively crystalloids for fluid therapy (Crystalloid group, n = 93). Primary outcome was the incidence of acute kidney injury.

RESULTS

The study groups had similar characteristics except for initial SAPS scores, incidence of vasospasm and ICU length of stay. Patients receiving HES fulfilled significantly more often SIRS (systemic inflammatory response syndrome) criteria. 24.6% (45/183) of the patients in the HES group had acute kidney injury (KDIGO 1-3) at any time during their ICU stay compared to 26.9% (25/93) in the crystalloid group (p = 0.679). Only few patients needed renal replacement therapy with no significant difference between groups (Crystalloid group: 4.3%; HES group: 2.2%; p = 0.322). The incidence of vasospasm was increased in the HES group when compared to the crystalloid group (33.9% vs. 17.2%; p = 0.004).

CONCLUSION

In the presented series of patients with non-traumatic SAH we found no significant association between HES therapy and the incidence of acute kidney injury. Treatment without HES did not worsen patient outcome.

Acute kidney injury in major abdominal surgery: incidence, risk factors, pathogenesis and outcomes

Acute kidney injury (AKI) is a common complication in patients undergoing major abdominal surgery. Various recent studies using modern standardized classifications for AKI reported a variable incidence of AKI after major abdominal surgery ranging from 3 to 35%. Several patient-related, procedure-related factors and postoperative complications were identified as risk factors for AKI in this setting. AKI following major abdominal surgery has been shown to be associated with poor short- and long-term outcomes. Herein, we provide a contemporary and critical review of AKI after major abdominal surgery focusing on its incidence, risk factors, pathogeny and outcomes.

Management of traumatic brain injury patients

Traumatic brain injury (TBI) has been called the ‘silent epidemic’ of modern times, and is the leading cause of mortality and morbidity in children and young adults in both developed and developing nations worldwide. In recent years, the treatment of TBI has undergone a paradigm shift. The management of severe TBI is ideally based on protocol-based guidelines provided by the Brain Trauma Foundation. The aims and objectives of its management are prophylaxis and prompt management of intracranial hypertension and secondary brain injury, maintenance of cerebral perfusion pressure, and ensuring adequate oxygen delivery to injured brain tissue. In this review, the authors discuss protocol-based approaches to the management of severe TBI as per recent guidelines.

Postoperative Visceral Tissue Edema Assessed by Computed Tomography Is a Predictor for Severe Complications After Pancreaticoduodenectomy

BACKGROUND/AIMS

In pancreatoduodenectomy (PD), the adverse impact of tissue edema owing to intraoperative fluid overload remains unclear. This study aims to evaluate how visceral tissue edema due to fluid overload affects severe postoperative complications after PD. It aims to clarify the usefulness of assessment by computed tomography (CT) of postoperative tissue edema.

METHODS

We classified 200 patients who underwent PD as either liberal fluid management (LFM) group (n = 100) or goal-directed fluid therapy (GDFT) group (n = 100), based on intraoperative fluid management. We assessed postoperative tissue edema by cross section of the body trunk area using pre- and postoperative CT.

RESULTS

Severe complication (Clavien-Dindo more than grade III) rate was significantly higher in LFM group than GDFT group (37 vs. 17%, P = 0.001). Independent risk factors of severe complications after PD included diameter of main pancreatic duct ≤ 3 mm at the cut surface (P = 0.041; OR 2.274; 95% CI 1.034-5.001), LFM (P = 0.005; OR 2.720; 95% CI 1.355-5.462), and increased rate of body trunk area ≥ 20% (P < 0.001; OR 3.448; 95% CI 1.723-5.462). In subgroup analysis of patients with no transfusion, LFM and increased rate of body trunk area ≥ 20% were independent risk factors of severe postoperative complications.

CONCLUSIONS

Visceral tissue edema evaluation is a valuable method to predict severe complications after PD.

Intravenous fluid selection rationales in acute clinical management

BACKGROUND

Intravenous fluid (IVF) is commonly used in acute clinical management. This study aimed to review the choice and primary considerations in IVF prescriptions and to evaluate the adequacy of guidelines and trainings on it in the New Territories West Cluster (NTWC) of Hong Kong.

METHODS

This is a descriptive study based on data collected from an online survey. Data were processed by SPSS for statistical analysis. This study focused on a general description and doctor-nurse between group comparison. Participants were asked the choice of IVF for nine acute clinical scenarios and provide reason. A 1-10 scale was used to assess the sufficiency of guideline, training and information, and time for revision on IVF prescription.

RESULTS

0.9% sodium chloride was the most familiar IVF (36%), followed by 5% Dextrose solution (26%). In the nine scenarios, the most chosen IVF was 0.9% sodium chloride (37%-61%). There was significant difference in the choice of IVF between doctors and nurses in 7 cases. The second most chosen IVF for doctors was Plasma-Lyte A while that for nurses was Gelofusine. Departmental practice was the most chosen reason to account for the prescription. The adequacy of guideline, information and training, and time for revision was rated 5. Doctors had significantly more time at work than nurses to update knowledge in IVF prescription (5.41 versus 4.57).

CONCLUSION

0.9% sodium chloride was mostly chosen. The choice of IVF was mainly based on departmental practice. Adequacy of guideline, information and training, and time for revision on IVF prescription were average, indicating significant training deficit.

Damage Control for Vascular Trauma from the Prehospital to the Operating Room Setting

Early management of vascular injury, starting at the field, is imperative for survival no less than any operative maneuver. Contemporary prehospital management of vascular trauma, including appropriate fluid and volume infusion, tourniquets, and hemostatic agents, has reversed the historically known limb hemorrhage as a leading cause of death. In this context, damage control (DC) surgery has evolved to DC resuscitation (DCR) as an overarching concept that draws together preoperative and operative interventions aiming at rapidly reducing bleeding from vascular disruption, optimizing oxygenation, and clinical outcomes. This review addresses contemporary DCR techniques from the prehospital to the surgical setting, focusing on civilian vascular injuries.

The effectiveness of prehospital hypertonic saline for hypotensive trauma patients: a systematic review and meta-analysis

Background

The optimal prehospital fluid for the treatment of hypotension is unknown. Hypertonic fluids may increase circulatory volume and mute the pro-inflammatory response of the body to injury and illness. The purpose of this systematic review is to determine whether in patients presenting with hypotension in the prehospital setting (population), the administration of hypertonic saline (intervention), compared to an isotonic fluid (control), improves survival to hospital discharge (outcome).

Methods

Searches were conducted in Medline, Embase, CINAHL, and CENTRAL from the date of database inception to November, 2016, and included all languages. Two reviewers independently selected randomized control trials of hypotensive human participants administered hypertonic saline in the prehospital setting. The comparison was isotonic fluid, which included normal saline, and near isotonic fluids such as Ringer’s Lactate. Assessment of study quality was done using the Cochrane Collaborations’ risk of bias tool and a fixed effect meta-analysis was conducted to determine the pooled relative risk of survival to hospital discharge. Secondary outcomes were reported for fluid requirements, multi-organ failure, adverse events, length of hospital stay, long term survival and disability.

Results

Of the 1160 non-duplicate citations screened, thirty-eight articles underwent full-text review, and five trials were included in the systematic review. All studies administered a fixed 250 ml dose of 7.5% hypertonic saline, except one that administered 300 ml. Two studies used normal saline, two Ringer’s Lactate, and one Ringer’s Acetate as control. Routine care co-interventions included isotonic fluids and colloids. Five studies were included in the meta-analysis (n = 1162 injured patients) with minimal statistical heterogeneity (I² = 0%). The pooled relative risk of survival to hospital discharge with hypertonic saline was 1.02 times that of patients who received isotonic fluids (95% Confidence Interval: 0.95, 1.10). There were no consistent statistically significant differences in secondary outcomes.

Conclusions

There was no significant difference in important clinical outcomes for hypotensive injured patients administered hypertonic saline compared to isotonic fluid in the prehospital setting. Hypertonic saline cannot be recommended for use in prehospital clinical practice for the management of hypotensive injured patients based on the available data.

PROSPERO registration # CRD42016053385.

A Systematic Review of Neuroprotective Strategies during Hypovolemia and Hemorrhagic Shock

Severe trauma constitutes a major cause of death and disability, especially in younger patients. The cerebral autoregulatory capacity only protects the brain to a certain extent in states of hypovolemia; thereafter, neurological deficits and apoptosis occurs. We therefore set out to investigate neuroprotective strategies during haemorrhagic shock. This review was performed in accordance to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Before the start of the search, a review protocol was entered into the PROSPERO database. A systematic literature search of Pubmed, Web of Science and CENTRAL was performed in August 2017. Results were screened and evaluated by two researchers based on a previously prepared inclusion protocol. Risk of bias was determined by use of SYRCLE’s risk of bias tool. The retrieved results were qualitatively analysed. Of 9093 results, 119 were assessed in full-text form, 16 of them ultimately adhered to the inclusion criteria and were qualitatively analyzed. We identified three subsets of results: (1) hypothermia; (2) fluid therapy and/or vasopressors; and (3) other neuroprotective strategies (piracetam, NHE1-inhibition, aprotinin, human mesenchymal stem cells, remote ischemic preconditioning and sevoflurane). Overall, risk of bias according to SYRCLE’s tool was medium; generally, animal experimental models require more rigorous adherence to the reporting of bias-free study design (randomization, etc.). While the individual study results are promising, the retrieved neuroprotective strategies have to be evaluated within the current scientific context—by doing so, it becomes clear that specific promising neuroprotective strategies during states of haemorrhagic shock remain sparse. This important topic therefore requires more in-depth research.

Perioperative fluid management in major hepatic resection: an integrative review

BACKGROUND

Fluid intervention and vasoactive pharmacological support during hepatic resection depend on the preference of the attending clinician, institutional resources, and practice culture. Evidence-based recommendations to guide perioperative fluid management are currently limited. Therefore, we provide a contemporary clinical integrative overview of the fundamental principles underpinning fluid intervention and hemodynamic optimization for adult patients undergoing major hepatic resection.

DATA SOURCES

A literature review was performed of MEDLINE, EMBASE and the Cochrane Central Registry of Controlled Trials using the terms "surgery", "anesthesia", "starch", "hydroxyethyl starch derivatives", "albumin", "gelatin", "liver resection", "hepatic resection", "fluids", "fluid therapy", "crystalloid", "colloid", "saline", "plasma-Lyte", "plasmalyte", "hartmann's", "acetate", and "lactate". Search results for MEDLINE and EMBASE were additionally limited to studies on human populations that included adult age groups and publications in English.

RESULTS

A total of 113 articles were included after appropriate inclusion criteria screening. Perioperative fluid management as it relates to various anesthetic and surgical techniques is discussed.

CONCLUSIONS

Clinicians should have a fundamental understanding of the surgical phases of the resection, hemodynamic goals, and anesthesia challenges in attempts to individualize therapy to the patient's underlying pathophysiological condition. Therefore, an ideal approach for perioperative fluid therapy is always individualized. Planning and designing large-scale clinical trials are imperative to define the optimal type and amount of fluid for patients undergoing major hepatic resection. Further clinical trials evaluating different intraoperative goal-directed strategies are also eagerly awaited.

Characterization of hypoalbuminemia following temporary abdominal closure

BACKGROUND

The purpose of this study was to characterize associations among serum proteins, negative-pressure wound therapy (NPWT) fluid loss, and primary fascial closure (PFC) following emergent laparotomy and temporary abdominal closure (TAC). We hypothesized that high levels of C-reactive protein (CRP) and NPWT output would be associated with hypoalbuminemia and failure to achieve PFC.

METHODS

We performed a retrospective analysis of 233 patients managed with NPWT TAC. Serum proteins and resuscitation indices were assessed on admission, initial laparotomy, and then at 48 hours, 96 hours, 7 days, and discharge. Correlations were assessed by Pearson coefficient. Multivariable regression was performed to identify predictors of PFC with cutoff values for continuous variables determined by Youden index.

RESULTS

Patients who failed to achieve PFC (n = 55) had significantly higher CRP at admission (249 vs. 148 mg/L, p = 0.003), initial laparotomy (237 vs. 154, p = 0.002), and discharge (124 vs. 72, p = 0.003), as well as significantly lower serum albumin at 7 days (2.3 vs. 2.5 g/dL, p = 0.028) and discharge (2.5 vs. 2.8, p = 0.004). Prealbumin (in milligrams per deciliter) was similar between groups at each time point. There was an inverse correlation between nadir serum albumin and total milliliters of NPWT output (r = -0.33, p < 0.001). Exogenous albumin administration (in grams per day) correlated with higher serum albumin levels at each time point: 48 hours: r = 0.26 (p = 0.002), 96 hours: r = 0.29 (p = 0.002), 7 days: r = 0.40 (p < 0.001). Albumin of less than 2.6 g/dL was an independent predictor of failure to achieve PFC (odds ratio, 2.59; 95% confidence interval, 1.02-6.61) in a multivariate model including abdominal sepsis, body mass index of greater than 40 kg/m, and CRP of greater than 250 mg/L.

CONCLUSIONS

Early and persistent systemic inflammation and high NPWT output were associated with hypoalbuminemia, which was an independent predictor of failure to achieve PFC. The utility of exogenous albumin following TAC requires further study.

LEVEL OF EVIDENCE

Prognostic study, level III; Therapeutic study, level IV.

Current Trends in Volume Replacement Therapy and the Use of Synthetic Colloids in Small Animals-An Internet-Based Survey (2016)

The use of synthetic colloids (SCs), particularly hydroxyethyl starch (HES), in people has changed in recent years following new evidence raising concerns about their efficacy and safety. Although fluid therapy guidelines for small animals are often extrapolated from human medicine, little information exists on current practice in veterinary medicine. The objective of the present study was to investigate current fluid selection, use of plasma volume expanders including SCs, and recent changes in their use in small animal practice. An Internet-based survey was conducted, inviting veterinarians to report their practices in fluid resuscitation and colloid osmotic pressure support, their choice of SC, and perceived adverse effects and contraindications associated with SC use. There were 1,134 respondents from 42 countries, including 46% general practitioners and 38% diplomates. Isotonic crystalloids, HES, and hypertonic saline were chosen by most respondents for fluid resuscitation, and HES by 75% of respondents for colloid osmotic support. Dextran and gelatin were used by some European respondents. Human serum albumin was used more than canine albumin but 45% of respondents, particularly those from Australia and New Zealand, used no albumin product. The majority (70%) of respondents changed their practice regarding SCs in recent years (mostly by limiting their use), largely due to safety concerns. However, only 27% of respondents worked in an institution that had a general policy on SC use. Impaired renal function, coagulopathy, and hypertension were most often considered contraindications; impaired coagulation tests and increased respiratory rate were the most frequently perceived adverse effects. The use of HES remains widespread practice in small animals, regardless of geographic location. Nevertheless, awareness of safety issues and restrictions on the use of SCs imposed in human medicine seems to have prompted a decrease in use of SCs by veterinarians. Given the paucity of evidence regarding efficacy and safety, and differences in cohorts between human and veterinary critical care patients, studies are needed to establish evidence-based guidelines specific for dogs and cats.

Intravenous Fluid Challenge Decreases Intracellular Volume: A Bioimpedance Spectroscopy-Based Crossover Study in Healthy Volunteers

The effects of intravenous fluid therapy on fluid compartments and hemodynamics of the human body remain enigmatic. We therefore tested the efficacy of bioimpedance spectroscopy in a crossover study, where 15 males received 0.5 ml/kg/min ELO-MEL-isoton (osmolarity = 302 mosmol/l) during 60 minutes, or nothing at all. In group “Fluid”, fluid load increased from −0.2 ± 1.0 l extracellular volume at baseline to its maximum of 1.0 ± 0.9 l in minute 70, and remained continuously elevated throughout minute 300. In group “Zero”, fluid load decreased from 0.5 ± 1.1 l at baseline to its minimum of −1.1 ± 1.1 l in minute 300. In group “Fluid”, intracellular volume decreased from 26.8 ± 3.9 l at baseline to its minimum of 26.0 ± 3.9 l in minute 70, and remained continuously decreased throughout minute 300. In group “Zero”, intracellular volume increased from 26.5 ± 3.8 l at baseline to its maximum of 27.1 ± 3.9 l in minute 120, and decreased thereafter. In group “Fluid” compared to “Zero”, systolic blood pressure was significantly higher, from minute 50–90. In conclusion, intravenous fluid therapy caused a clinically meaningful, sustained increase in fluid load, and a decrease in intracellular volume. These data raise interest in studying fluid administration by the gastrointestinal route, perhaps even when managing critical illness.

Impact of volume status and volume therapy on the kidney

Volume resuscitation to correct hypotension in surgical and critically ill patients is a common practice. Available evidence suggests that iatrogenic volume overload is associated with worse outcomes in established acute kidney injury. Intraoperative arterial hypotension is associated with postoperative renal dysfunction, and prompt correction with fluid management protocols that combine inotrope infusions with volume therapy targeted to indices of volume responsiveness should be considered. From the perspective of renal function, the minimum amount of intravenous fluid required to maintain perfusion and oxygen delivery is desirable. Available evidence and expert opinion suggest that balanced crystalloid solutions are preferable to isotonic saline for volume resuscitation. Moreover, albumin has a similar safety profile as crystalloids. Hetastarch-containing colloids have a clear association with acute kidney injury.

Techniques for preventing hypotension during spinal anaesthesia for caesarean section

BACKGROUND

Maternal hypotension is the most frequent complication of spinal anaesthesia for caesarean section. It can be associated with nausea or vomiting and may pose serious risks to the mother (unconsciousness, pulmonary aspiration) and baby (hypoxia, acidosis, neurological injury).

OBJECTIVES

To assess the effects of prophylactic interventions for hypotension following spinal anaesthesia for caesarean section.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (9 August 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials, including full texts and abstracts, comparing interventions to prevent hypotension with placebo or alternative treatment in women having spinal anaesthesia for caesarean section. We excluded studies if hypotension was not an outcome measure.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and extracted data from eligible studies. We report 'Summary of findings' tables using GRADE.

MAIN RESULTS

We included 126 studies involving 9565 participants. Interventions were to prevent maternal hypotension following spinal anaesthesia only, and we excluded any interventions considered active treatment. All the included studies reported the review's primary outcome. Across 49 comparisons, we identified three intervention groups: intravenous fluids, pharmacological interventions, and physical interventions. Authors reported no serious adverse effects with any of the interventions investigated. Most trials reported hypotension requiring intervention and Apgar score of less than 8 at five minutes as the only outcomes. None of the trials included in the comparisons we describe reported admission to neonatal intensive care unit. Crystalloid versus control (no fluids)Fewer women experienced hypotension in the crystalloid group compared with no fluids (average risk ratio (RR) 0.84, 95% confidence interval (CI) 0.72 to 0.98; 370 women; 5 studies; low-quality evidence). There was no clear difference between groups in numbers of women with nausea and vomiting (average RR 0.19, 95% CI 0.01 to 3.91; 1 study; 69 women; very low-quality evidence). No baby had an Apgar score of less than 8 at five minutes in either group (60 babies, low-quality evidence). Colloid versus crystalloidFewer women experienced hypotension in the colloid group compared with the crystalloid group (average RR 0.68, 95% CI 0.58 to 0.80; 2105 women; 28 studies; very low-quality evidence). There were no clear differences between groups for maternal hypertension requiring intervention (average RR 0.64, 95% CI 0.09 to 4.46, 3 studies, 327 women;very low-quality evidence), maternal bradycardia requiring intervention (average RR 0.99, 95% CI 0.55 to 1.79, 6 studies, 509 women; very low-quality evidence), nausea and/or vomiting (average RR 0.83, 95% CI 0.61 to 1.13, 15 studies, 1154 women, I² = 37%; very low-quality evidence), neonatal acidosis (average RR 0.83, 95% CI 0.15 to 4.52, 6 studies, 678 babies; very low-quality evidence), or Apgar score of less than 8 at five minutes (average RR 0.24, 95% CI 0.03 to 2.05, 11 studies, 826 babies; very low-quality evidence). Ephedrine versus phenylephrineThere were no clear differences between ephedrine and phenylephrine groups for preventing maternal hypotension (average RR 0.92, 95% CI 0.71 to 1.18; 401 women; 8 studies; very low-quality evidence) or hypertension (average RR 1.72, 95% CI 0.71 to 4.16, 2 studies, 118 women, low-quality evidence). Rates of bradycardia were lower in the ephedrine group (average RR 0.37, 95% CI 0.21 to 0.64, 5 studies, 304 women, low-quality evidence). There was no clear difference in the number of women with nausea and/or vomiting (average RR 0.76, 95% CI 0.39 to 1.49, 4 studies, 204 women, I² = 37%, very low-quality evidence), or babies with neonatal acidosis (average RR 0.89, 95% CI 0.07 to 12.00, 3 studies, 175 babies, low-quality evidence). No baby had an Apgar score of less than 8 at five minutes in either group (321 babies; low-quality evidence). Ondansetron versus controlOndansetron administration was more effective than control (placebo saline) for preventing hypotension requiring treatment (average RR 0.67, 95% CI 0.54 to 0.83; 740 women, 8 studies, low-quality evidence), bradycardia requiring treatment (average RR 0.49, 95% CI 0.28 to 0.87; 740 women, 8 studies, low-quality evidence), and nausea and/or vomiting (average RR 0.35, 95% CI 0.24 to 0.51; 653 women, 7 studies, low-quality evidence). There was no clear difference between the groups in rates of neonatal acidosis (average RR 0.48, 95% CI 0.05 to 5.09; 134 babies; 2 studies, low-quality evidence) or Apgar scores of less than 8 at five minutes (284 babies, low-quality evidence). Lower limb compression versus controlLower limb compression was more effective than control for preventing hypotension (average RR 0.61, 95% CI 0.47 to 0.78, 11 studies, 705 women, I² = 65%, very low-quality evidence). There was no clear difference between the groups in rates of bradycardia (RR 0.63, 95% CI 0.11 to 3.56, 1 study, 74 women, very low-quality evidence) or nausea and/or vomiting (average RR 0.42 , 95% CI 0.14 to 1.27, 4 studies, 276 women, I² = 32%, very-low quality evidence). No baby had an Apgar score of less than 8 at five minutes in either group (130 babies, very low-quality evidence). Walking versus lyingThere was no clear difference between the groups for women with hypotension requiring treatment (RR 0.71, 95% CI 0.41 to 1.21, 1 study, 37 women, very low-quality evidence).Many included studies reported little to no information that would allow an assessment of their risk of bias, limiting our ability to draw meaningful conclusions. GRADE assessments of the quality of evidence ranged from very low to low. We downgraded evidence for limitations in study design, imprecision, and indirectness; most studies assessed only women scheduled for elective caesarean sections.External validity also needs consideration. Readers should question the use of colloids in this context given the serious potential side effects such as allergy and renal failure associated with their administration.

AUTHORS' CONCLUSIONS

While interventions such as crystalloids, colloids, ephedrine, phenylephrine, ondansetron, or lower leg compression can reduce the incidence of hypotension, none have been shown to eliminate the need to treat maternal hypotension in some women. We cannot draw any conclusions regarding rare adverse effects associated with use of the interventions (for example colloids) due to the relatively small numbers of women studied.

Balanced versus isotonic saline resuscitation-a systematic review and meta-analysis of randomized controlled trials in operation rooms and intensive care units

BACKGROUND

Fluid resuscitation is the cornerstone in treatment of shock, and intravenous fluid administration is the most frequent intervention in operation rooms and intensive care units (ICUs). The composition of fluids used for fluid resuscitation gained interest over the past decade, with recent focus on whether balanced solutions should be preferred over isotonic saline.

METHODS

Systematic review and meta-analysis of randomized controlled trials (RCTs) comparing fluid resuscitation with a balanced solution versus isotonic saline in adult patients in operation room or ICUs. Primary outcome was in-hospital mortality, secondary outcomes included occurrence of acute kidney injury (AKI) and need for renal replacement therapy (RRT).

RESULTS

The search identified 11 RCTs involving 2,703 patients; 8 trials were conducted in operation room and 3 in ICU. In-hospital mortality, as well as the occurrence of AKI and need for RRT was not different between resuscitation with balanced solutions versus isotonic saline, neither in operation room nor in ICU patients. Serum chloride levels, but not arterial pH, were significantly lower in patients resuscitated with balanced solutions.

CONCLUSIONS

Currently evidence insufficiently supports the use of balanced over isotonic saline for fluid resuscitation to improve outcome of operation room and ICU patients.

Future Therapies in Burn Resuscitation

Since the 1940s, the resuscitation of burn patients has evolved with dramatic improvements in mortality. The most significant achievement remains the creation and adoption of formulae to calculate estimated fluid requirements to guide resuscitation. Modalities to attenuate the hypermetabolic phase of injury include pharmacologic agents, early enteral nutrition, and the aggressive approach of early excision of large injuries. Recent investigations into the genomic response to severe burns and the application of computer-based decision support tools will likely guide future resuscitation, with the goal of further reducing mortality and morbidity, and improving functional and quality of life outcomes.

Is Brain-Dead Donor Fluid Therapy With Colloids Associated With Better Kidney Grafts?

OBJECTIVES

Fluid therapy is required to maintain perfusion to donor organs. Recent reviews on the choices of fluids have emphasized the safety of using crystalloids, as opposed to fluid therapy with colloids, which has been reported to be either unequivocally or potentially harmful in a number of studies on various patient populations. We aimed to analyze whether the type of fluid administered to donors is connected with kidney transplant outcomes.

MATERIALS AND METHODS

A total of 100 consecutive brain-dead multiorgan donors and their respective 181 kidney recipients were studied retrospectively. Data concerning donor fluid therapy, the characteristics of the donors and the recipients, and outcomes after kidney transplant were extracted from organ retrieval and patient records. Cases with early graft function were compared with cases with delayed graft function.

RESULTS

Donors had received both crystalloids and colloids in most cases (84%). Fluid therapy with crystalloids alone was more common among the 40 recipients with delayed (30%) than in the 103 recipients with early graft function (11%) (P = .005). Donor age, time on renal replacement therapy before transplant, and donor fluid therapy with crystalloids alone were independent risk factors for delayed graft function in multivariate analysis.

CONCLUSIONS

Our results suggest that donor fluid therapy including colloids could be beneficial instead of harmful compared with treatment with crystalloids alone. This finding needs to be evaluated in prospective studies.

Review of Evidence for Adult Diabetic Ketoacidosis Management Protocols

BACKGROUND

Diabetic ketoacidosis (DKA) is an endocrine emergency with associated risk of morbidity and mortality. Despite this, DKA management lacks strong evidence due to the absence of large randomised controlled trials (RCTs).

OBJECTIVE

To review existing studies investigating inpatient DKA management in adults, focusing on intravenous (IV) fluids; insulin administration; potassium, bicarbonate, and phosphate replacement; and DKA management protocols and impact of DKA resolution rates on outcomes.

METHODS

Ovid Medline searches were conducted with limits "all adult" and published between "1973 to current" applied. National consensus statements were also reviewed. Eligibility was determined by two reviewers' assessment of title, abstract, and availability.

RESULTS

A total of 85 eligible articles published between 1973 and 2016 were reviewed. The salient findings were (i) Crystalloids are favoured over colloids though evidence is lacking. The preferred crystalloid and hydration rates remain contentious. (ii) IV infusion of regular human insulin is preferred over the subcutaneous route or rapid acting insulin analogues. Administering an initial IV insulin bolus before low-dose insulin infusions obviates the need for supplemental insulin. Consensus-statements recommend fixed weight-based over "sliding scale" insulin infusions although evidence is weak. (iii) Potassium replacement is imperative although no trials compare replacement rates. (iv) Bicarbonate replacement offers no benefit in DKA with pH > 6.9. In severe metabolic acidosis with pH < 6.9, there is lack of both data and consensus regarding bicarbonate administration. (v) There is no evidence that phosphate replacement offers outcome benefits. Guidelines consider replacement appropriate in patients with cardiac dysfunction, anaemia, respiratory depression, or phosphate levels <0.32 mmol/L. (vi) Upon resolution of DKA, subcutaneous insulin is recommended with IV insulin infusions ceased with an overlap of 1-2 h. (vii) DKA resolution rates are often used as end points in studies, despite a lack of evidence that rapid resolution improves outcome. (viii) Implementation of DKA protocols lacks strong evidence for adherence but may lead to improved clinical outcomes.

CONCLUSION

There are major deficiencies in evidence for optimal management of DKA. Current practice is guided by weak evidence and consensus opinion. All aspects of DKA management require RCTs to affirm or redirect management and formulate consensus evidence-based practice to improve patient outcomes.

Fluid Resuscitation of the Adult Trauma Patient: Where Have We Been and Where Are We Going?

The resuscitation of an adult trauma patient has been researched and written about for the past century. Throughout those discussions, 2 major controversies persist when discussing resuscitation methods: (1) the ideal choice of fluid type to use during the initial resuscitation period, and (2) the ideal fluid volume to infuse during the initial resuscitation period. This article presents a brief historical perspective of fluids used during a trauma resuscitation, along with the latest research findings as they relate to the 2 stated issues.

Acute Fluid Management of Large Burns: Pathophysiology, Monitoring, and Resuscitation

This article reviews the pathophysiology of large burn injury and the extreme fluid shifts that occur in the hours and days after this event. The authors focus on acute fluid management, monitoring of hemodynamic status, and end points of resuscitation. Understanding the need and causes for fluid resuscitation after burn injury helps the clinician develop an effective plan to balance the competing goals of normalized tissue perfusion and limited tissue edema. Thoughtful, individualized treatment is the best answer and the most effective compromise.

Postinjury Inflammation and Organ Dysfunction

The development of organ dysfunction (OD) is related to the intensity and balance between trauma-induced simultaneous, opposite inflammatory responses. Early proinflammation via innate immune system activation may cause early OD, whereas antiinflammation, via inhibition of the adaptive immune system and apoptosis, may induce immunoparalysis, impaired healing, infections, and late OD. Patients discharged with low-level OD may develop the persistent inflammation-immunosuppression catabolism syndrome. Although the incidence of multiple organ failure has decreased over time, it remains morbid, lethal, and resource intensive. However, single OD, especially acute lung injury, remains frequent. Treatment is limited, and prevention remains the mainstay strategy.

[Care for severely injured persons : Update of the 2016 S3 guideline for the treatment of polytrauma and the severely injured]

In 2011 the first interdisciplinary S3 guideline for the management of patients with serious injuries/trauma was published. After intensive revision and in consensus with 20 different medical societies, the updated version of the guideline was published online in September 2016. It is divided into three sections: prehospital care, emergency room management and the first operative phase. Many recommendations and explanations were updated, mostly in the prehospital care and emergency room management sections. These two sections are of special interest for anesthesiologists in field emergency physician roles or as team members or team leaders in the emergency room. The present work summarizes the changes to the current guideline and gives a brief overview of this very important work.

Identification and Management of Obstetric Hemorrhage

Obstetric hemorrhage remains the leading cause of maternal death and severe morbidity worldwide. Although uterine atony is the most common cause of peripartum bleeding, abnormal placentation, coagulation disorders, and genital tract trauma contribute to adverse maternal outcomes. Given the inability to reliably predict patients at high risk for obstetric hemorrhage, all parturients should be considered susceptible, and extreme vigilance must be exercised in the assessment of blood loss and hemodynamic stability during the peripartum period. Obstetric-specific hemorrhage protocols, facilitating the integration and timely escalation of pharmacologic, radiological, surgical, and transfusion interventions, are critical to the successful management of peripartum bleeding.

Use of intravenous fluids/solutions: a narrative review

OBJECTIVE

Intravenous fluids are broadly categorized into colloids and crystalloids. The aim of this review is to present under a clinical point of view the characteristics of intravenous fluids that make them more or less appropriate either for maintaining hydration when enteral intake is contraindicated or for treating hypovolemia.

METHODS

We considered randomized trials and meta-analyses as well as narrative reviews evaluating the effects of colloids or crystalloids in patients with hypovolemia or as maintenance fluids published in the PubMed and Cochrane databases.

RESULTS

Clinical studies have not shown a greater clinical benefit of albumin solutions compared with crystalloid solutions. Furthermore, albumin and colloid solutions may impair renal function, while there is no evidence that the administration of colloids reduces the risk of death compared with resuscitation with crystalloids in patients with trauma, burns or following surgery. Among crystalloids, normal saline is associated with the development of hyperchloremia-induced impairment of kidney function and metabolic acidosis. On the other hand, the other commonly used crystalloid solution, the Ringer's Lactate, has certain indications and contraindications. These matters, along with the basic principles of the administration of potassium chloride and bicarbonate, are meticulously discussed in the review.

CONCLUSIONS

Intravenous fluids should be dealt with as drugs, as they have specific clinical indications, contraindications and adverse effects.

The effect of perioperative fluid management on postoperative ileus in rectal cancer patients

BACKGROUND

Postoperative ileus is a common cause of increased morbidity and cost after operative intervention. The aim of this study was to assess how fluid type, volume, and timing may affect incidence of postoperative ileus.

METHODS

A retrospective cohort study was performed on patients undergoing operative intervention for rectal cancer from 2008 to 2015 at a single institution. Univariate and multivariate analyses were used to assess the effect of type (crystalloid versus colloid), volume by quartile, and timing (perioperative versus postoperative) on rate of postoperative ileus.

RESULTS

A total of 300 patients were included, and the overall incidence of ileus in our cohort was 30% (n = 90). Both univariate and multivariate analyses showed that increasing volume of crystalloid volume administered was associated with increased postoperative ileus incidence (first quartile: 16.3%; second quartile: 31.5%, third quartile: 34.2%; and fourth quartile: 39.2%; P = .012), and administration of colloid was not shown to correlate. Furthermore, timing was not shown to be associated with the rate of postoperative ileus.

CONCLUSION

Increased volumes of crystalloid are associated with higher rates of ileus, while administration of colloid is not. Based on this retrospective data, limiting the volume of crystalloid perioperatively may help lower the rate of ileus postoperatively.

Intraoperative fluid management

Evidence-based medicine has been slow to address the critically important issue of intraoperative fluid maintenance for surgical patients. A "rule" published by Holliday and colleagues in 1957 was the accepted practice for the initial calculation of fluid maintenance for nearly 50 years. Using this formula, the nil per os fluid deficit was based on how long it had been since the preoperative patient had last consumed anything by mouth, even water. New technology and monitoring modalities are being used to guide evidence-supported intraoperative care, leading to better outcomes for surgical patients.