Comparisons of Electrolyte Balance Efficacy of Two Gelatin-Balanced Crystalloid for Surgery Patients Under General Anesthesia: A Multi-Center, Prospective, Randomized, Single-Blind, Controlled Study

Purpose

This study aimed to compare the electrolyte balance efficacies of two Gelatin-Balanced Crystalloid in clinical applications.

Methods

A multi-center, prospective, randomized, single-blind, parallel controlled study was conducted among non-cardiac surgery patients, with clinical registration number ChiCTR2200062999. They were randomized into Succinylated Gelatin, Multiple Electrolytes and Sodium Acetate Injection (SG-MESAI) group (experimental group) and Succinylated Gelatin Injection (SGI) infusion group (control group). The same anesthetic induction technique, anesthetic method, and calculation method for the volume of colloid infusion were used in the two groups. Between-group differences in the changes in base excess (BE), Chloride ion (Cl-), bicarbonate radical (HCO3⁻) and other parameters were recorded at 15 min, 30 min after the infusion relative to the baseline. Hemodynamic indicators were determined at 30 min after colloid infusion. Safety follow-up was conducted by administering the following tests within 48 h±12 h after surgery.

Results

A total of 225 subjects (full analysis set) were finally enrolled, with 110 subjects in the experimental group and 115 subjects in the control group. The baseline data were comparable between the two groups. At 15 min after infusion, the mean changes in BE, Cl- and HCO3⁻ concentration in the experimental group were smaller than those of the control group (P<0.001). At 30 min after surgery, the mean changes in BE, Cl-, HCO3⁻concentration and pH value were smaller in the experimental group than in the control group (P<0.05). The incidences of adverse events and adverse reactions in the experimental group was less than the control group, but the difference was not statistically significant (P≥0.05). Besides, no serious adverse events or adverse reactions were reported in any subjects.

Conclusion

Succinylated Gelatin, Multiple Electrolytes and Sodium Acetate Injection maintained the balance of BE, Cl-, HCO3⁻ and pH value in a better way than Succinylated Gelatin Injection in non-cardiac surgery patients under general anesthesia.

Blood Urea Nitrogen-to-Albumin Ratio in Predicting Long-Term Mortality in Patients Following Coronary Artery Bypass Grafting: An Analysis of the MIMIC-III Database

Background

This study examined the role of blood urea nitrogen-to-albumin ratio (BAR) in predicting long-term mortality in patients undergoing coronary artery bypass grafting (CABG).

Methods

In this retrospective cohort study, patients undergoing CABG were enrolled from the Medical Information Mart for Intensive Care III (MIMIC III) database. Patients were divided into the three groups according to the optimal cutoff values of BAR determined by X-tile software. The survival curve was constructed by the Kaplan–Meier method and multivariate Cox regression analysis was performed to explore the independent prognostic factors of 1- and 4-year mortality after CABG. The receiver operating characteristic (ROC) curves and the areas under the ROC curves (AUCs) were calculated to estimate the accuracy of BAR in predicting the outcomes. Subgroup analyses were also carried out.

Results

A total of 1,462 patients at 4-year follow-up were included, of which 933, 293, and 236 patients were categorized into the group 1 (≤ 6.45 mg/g), group 2 (>6.45 and ≤ 10.23 mg/g), and group 3 (>10.23 mg/g), respectively. Non-survivors showed an increased level of BAR at both 1- (p < 0.001) and 4-year (p < 0.001) follow-up compared with the survivors. The patients with a higher BAR had a higher risk of 1- and 4-year mortality following CABG (33.05 vs. 14.33 vs. 5.14%, p < 0.001 and 52.97 vs. 30.72 vs. 13.08%, p < 0.001, respectively). Cox proportional hazards regression model suggested a higher BAR as an independent risk factor of 1-year mortality (HR 3.904; 95% CI 2.559–5.956; P < 0.001) and 4-year mortality (HR 2.895; 95% CI 2.138–3.921; P < 0.001) after adjusting for confounders. Besides, the receiver operating characteristic (ROC) curves showed the better predictive ability of BAR compared to other grading scores at both 1- (0.7383, 95% CI: 0.6966–0.7800) and 4-year mortality (0.7189, 95% CI: 0.6872–0.7506). Subgroup analysis demonstrated no heterogeneous results of BAR in 4-year mortality in particular groups of patient.

Conclusion

This report provided evidence of an independent association between 1- and 4-year mortality after CABG and BAR. A higher BAR was associated with a higher risk of long-term mortality and could serve as a prognostic predictor in patients following CABG.

The Endothelial Glycocalyx and Organ Preservation-From Physiology to Possible Clinical Implications for Solid Organ Transplantation

The endothelial glycocalyx is a thin layer consisting of proteoglycans, glycoproteins and glycosaminoglycans that lines the luminal side of vascular endothelial cells. It acts as a barrier and contributes to the maintenance of vascular homeostasis and microperfusion. During solid organ transplantation, the endothelial glycocalyx of the graft is damaged as part of Ischemia Reperfusion Injury (IRI), which is associated with impaired organ function. Although several substances are known to mitigate glycocalyx damage, it has not been possible to use these substances during graft storage on ice. Normothermic machine perfusion (NMP) emerges as an alternative technology for organ preservation and allows for organ evaluation, but also offers the possibility to treat and thus improve organ quality during storage. This review highlights the current knowledge on glycocalyx injury during organ transplantation, presents ways to protect the endothelial glycocalyx and discusses potential glycocalyx protection strategies during normothermic machine perfusion.

A Double-Blind, Randomized Control Trial of Rapidly Infused High Strong Ion Difference (SID) Fluid Versus Hartmann's Solution on Acid-Base Status in Sepsis Patients in the Emergency Department

BACKGROUND

Balanced fluids are preferred in initial resuscitation of septic patients based on several recent studies. The Stewart's concept on acid-base balance predicts that high strong ion difference (SID) fluid thus will increase the pH level. To date, the impact of high SID fluid in septic patient with metabolic acidosis remains uncertain. We conducted single center, randomized, double-blind trial to compare the effect of high SID fluid vs. Hartmann's solution on acid-base status in selected sepsis patients in the Emergency Department.

METHODS

Septic patient with hyperlactatemia and metabolic acidosis were randomized to receive either high SID fl uid or Hartmann's solution during initial fl uid resuscitation. The primary outcome measures the pH and bicarbonate levels difference pre- and post- resuscitation.

RESULTS

One hundred and sixty-two patients underwent randomization, 81 were assigned each to receive high SID fluid or Hartmann's solution. Both groups had similar baseline characteristics. High SID group received 23.5 mL/kg and the Hartmann's group received 22.7 mL/kg (p = 0.360). High SID fluid increased the mean (± SD) pH by 0.107 (± 0.09) vs. Hartmann's solution by 0.014 (± 0.12), p ≤ 0.001. Mean bicarbonate level increased signifi cantly in high SID group compared to Hartmann's (4.30 ± 3.76 vs. 1.25 ± 3.33, p ≤ 0.001). High SID group had higher post resuscitation lactate clearance than Hartmann's group (25.4 ± 28.3% vs. 12.0 ± 34.1%, p = 0.009). Shorter hospital stay was observed in highSID group 8.04 ± 5.96 days vs. Hartmann's group 12.18 ± 12.41 days (p = 0.048). Both groups showed no difference in incidence of pulmonary oedema, acute kidney injury and mortality.

CONCLUSIONS

Initial resuscitation using high SID fluid in selected septic patient improves pH and bicarbonate levels. The high SID group had better post resuscitation lactate clearance and shorter hospital stay.

Buffered solutions versus 0.9% saline for resuscitation in critically ill adults and children

BACKGROUND

Fluid therapy is one of the main interventions provided for critically ill patients, although there is no general consensus regarding the type of solution. Among crystalloid solutions, 0.9% saline is the most commonly administered. Buffered solutions may offer some theoretical advantages (less metabolic acidosis, less electrolyte disturbance), but the clinical relevance of these remains unknown.

OBJECTIVES

To assess the effects of buffered solutions versus 0.9% saline for resuscitation in critically ill adults and children.

SEARCH METHODS

We searched the following databases to July 2018: CENTRAL, MEDLINE, Embase, CINAHL, and four trials registers. We checked references, conducted backward and forward citation searching of relevant articles, and contacted study authors to identify additional studies. We imposed no language restrictions.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) with parallel or cross-over design examining buffered solutions versus intravenous 0.9% saline in a critical care setting (resuscitation or maintenance). We included studies on participants with critical illness (including trauma and burns) or undergoing emergency surgery during critical illness who required intravenous fluid therapy. We included studies of adults and children. We included studies with more than two arms if they fulfilled all of our inclusion criteria. We excluded studies performed in persons undergoing elective surgery and studies with multiple interventions in the same arm.

DATA COLLECTION AND ANALYSIS

We used Cochrane's standard methodological procedures. We assessed our intervention effects using random-effects models, but when one or two trials contributed to 75% of randomized participants, we used fixed-effect models. We reported outcomes with 95% confidence intervals (CIs).

MAIN RESULTS

We included 21 RCTs (20,213 participants) and identified three ongoing studies. Three RCTs contributed 19,054 participants (94.2%). Four RCTs (402 participants) were conducted among children with severe dehydration and dengue shock syndrome. Fourteen trials reported results on mortality, and nine reported on acute renal injury. Sixteen included trials were conducted in adults, four in the paediatric population, and one trial limited neither minimum or maximum age as an inclusion criterion. Eight studies involving 19,218 participants were rated as high methodological quality (trials with overall low risk of bias according to the domains: allocation concealment, blinding of participants/assessors, incomplete outcome data, and selective reporting), and in the remaining trials, some form of bias was introduced or could not be ruled out.We found no evidence of an effect of buffered solutions on in-hospital mortality (odds ratio (OR) 0.91, 95% CI 0.83 to 1.01; 19,664 participants; 14 studies; high-certainty evidence). Based on a mortality rate of 119 per 1000, buffered solutions could reduce mortality by 21 per 1000 or could increase mortality by 1 per 1000. Similarly, we found no evidence of an effect of buffered solutions on acute renal injury (OR 0.92, 95% CI 0.84 to 1.00; 18,701 participants; 9 studies; low-certainty evidence). Based on a rate of 121 per 1000, buffered solutions could reduce the rate of acute renal injury by 19 per 1000, or result in no difference in the rate of acute renal injury. Buffered solutions did not show an effect on organ system dysfunction (OR 0.80, 95% CI 0.40 to 1.61; 266 participants; 5 studies; very low-certainty evidence). Evidence on the effects of buffered solutions on electrolyte disturbances varied: potassium (mean difference (MD) 0.09, 95% CI -0.10 to 0.27; 158 participants; 4 studies; very low-certainty evidence); chloride (MD -3.02, 95% CI -5.24 to -0.80; 351 participants; 7 studies; very low-certainty evidence); pH (MD 0.04, 95% CI 0.02 to 0.06; 200 participants; 3 studies; very low-certainty evidence); and bicarbonate (MD 2.26, 95% CI 1.25 to 3.27; 344 participants; 6 studies; very low-certainty evidence).

AUTHORS' CONCLUSIONS

We found no effect of buffered solutions on preventing in-hospital mortality compared to 0.9% saline solutions in critically ill patients. The certainty of evidence for this finding was high, indicating that further research would detect little or no difference in mortality. The effects of buffered solutions and 0.9% saline solutions on preventing acute kidney injury were similar in this setting. The certainty of evidence for this finding was low, and further research could change this conclusion. Patients treated with buffered solutions showed lower chloride levels, higher levels of bicarbonate, and higher pH. The certainty of evidence for these findings was very low. Future research should further examine patient-centred outcomes such as quality of life. The three ongoing studies once published and assessed may alter the conclusions of the review.

Fluid Stewardship During Critical Illness: A Call to Action

Intravenous fluids (IVFs) are the most common drugs administered in the intensive care unit. Despite the ubiquitous use, IVFs are not benign and carry significant risks associated with under- or overadministration. Hypovolemia is associated with decreased organ perfusion, ischemia, and multi-organ failure. Hypervolemia and volume overload are associated with organ dysfunction, delayed liberation from mechanical ventilation, and increased mortality. Despite appropriate provision of IVF, adverse drug effects such as electrolyte abnormalities and acid-base disturbances may occur. The management of volume status in critically ill patients is both dynamic and tenuous, a process that requires frequent monitoring and high clinical acumen. Because patient-specific considerations for fluid therapy evolve across the continuum of critical illness, a standard approach to the assessment of fluid needs and prescription of IVF therapy is necessary. We propose the principle of "fluid stewardship," guided by 4 rights of medication safety: right patient, right drug, right route, and right dose. The successful implementation of fluid stewardship will aid pharmacists in making decisions regarding IVF therapy to optimize hemodynamic management and improve patient outcomes. Additionally, we highlight several areas of focus for future research, guided by the 4 rights construct of fluid stewardship.

Intravenous overload of fluids and sodium may contribute to the lower infusion of enteral nutrition in critically ill patients

OBJECTIVE

To evaluate the effects of intravenous infusion of fluids and sodium on the first day of admission on infusion of enteral nutrition in the first 5 days in intensive care patients.

METHODS

A prospective cohort study was conducted with critical nonsurgical patients admitted for at least 5 days who were on mechanical ventilation and receiving enteral nutrition. The amount of intravenous fluids and sodium infused on the first day and the volume of enteral nutrition infused in the first 5 days were investigated. The volume of intravenous fluids > 35mL/kg or ≤ 35mL/kg of body weight and sodium (above or below the 25th percentile) infused on the first day was compared with infused enteral nutrition.

RESULTS

A total of 86 patients were studied, with a mean (± standard deviation) of 65 ± 17 years, of which 54.7% were female. On the first day, 3,393.7 ± 1,417.0mL of fluid (48.2 ± 23.0mL/kg) and 12.2 ± 5.1g of sodium were administered. Fifty-eight (67.4%) patients received more than 35mL/kg of fluids. In 5 days, 67 ± 19.8% (2,993.8 ± 1,324.4mL) of the prescribed enteral nutrition was received. Patients who received > 35mL/kg of intravenous fluids also received less enteral nutrition in 5 days (2,781.4 ± 1,337.9 versus 3,433.6 ± 1,202.2mL; p = 0.03) versus those who received ≤ 35mL/kg. Patients with intravenous sodium infusion above the 25th percentile (≥ 8.73g) on the first day received less enteral nutrition volume in 5 days (2,827.2 ± 1,398.0 versus 3,509.3 ± 911.9mL; p = 0.02).

CONCLUSION

The results of this study support the assumption that the administration of intravenous fluids > 35mL/kg and sodium ≥ 8.73g on the first day of hospitalization may contribute to the lower infusion of enteral nutrition in critically ill patients.

Association between fluctuations in serum chloride levels and 30-day mortality among critically ill patients: a retrospective analysis

Background

This study investigated the associations of fluctuations in serum chloride (Cl⁻) levels with 30-day mortality after intensive care unit (ICU) admission among critically ill patients.

Methods

We retrospectively analyzed the medical records of adult patients (≥18 years old) admitted to the ICU between January 2012 and December 2017. Positive and negative fluctuations in Cl⁻ were defined as the differences between the Cl⁻ upon ICU admission (baseline Cl⁻) and the maximum and minimum Cl⁻ levels, respectively, measured within 72 h after ICU admission.

Results

The final analysis included 18,825 adult patients. In multivariable Cox regression analyses, the risk of 30-day mortality increased by 8% per 1-mmol L^− 1 positive fluctuation in Cl⁻ within 72 h (hazard ratio = 1.08, 95% confidence interval: 1.04–1.11, P < 0.001). In subgroup analyses, a positive fluctuation in Cl⁻ was associated with increased 30-day mortality among patients with a severe positive cumulative fluid balance (FB, > 10%), normochloremia (97–110 mmol L^− 1) or hyperchloremia (> 110 mmol L^− 1) upon ICU admission. Furthermore, a negative fluctuation in the Cl⁻ level during the first 72 h of an ICU stay was associated with a negative cumulative FB (< 0%) or hypochloremia (< 97 mmol L^− 1) upon ICU admission.

Conclusions

A fluctuation in the Cl⁻ level during the first 72 h of an ICU stay was found to associate independently with increased 30-day mortality among critically ill adult patients. However, the nature of this association differed according to the cumulative FB status or dyschloremia status upon ICU admission.

Electronic supplementary material

The online version of this article (10.1186/s12871-019-0753-3) contains supplementary material, which is available to authorized users.

Lactate versus acetate buffered crystalloid solutions: Protocol for a scoping review

BACKGROUND

Intravenous (IV) fluid therapy has become a ubiquitous intervention in everyday clinical practice. Several types of fluid are available including isotonic crystalloid fluids. Among crystalloid fluids, buffered solutions (derivatives of the original Hartmann's and Ringer's solutions) are increasingly recommended as first-line resuscitation fluids. However, the choice between different buffered solutions appears to be difficult with limited data to support the use of lactate vs. acetate buffered solutions. Accordingly, we aim at systematically describing the body of evidence on the use of the different types of buffered crystalloid solutions in hospitalised patients.

METHODS

We will conduct a scoping review of all study designs (i.e. no study design will per se be excluded from the proposed review) in accordance with the Preferred Reporting Items for Systematic reviews and Meta Analyses (PRISMA) statement.

RESULTS

We will provide descriptive analysis of the included studies/trials, i.e. no meta-analyses will be conducted. We will include studies on adult hospitalised patients receiving IV fluid for any reason. Studies must compare any crystalloid solution primarily buffered with lactate versus any primarily acetate buffered solution. All outcome measures will be reported. The quality of evidence will be assessed according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

CONCLUSION

This outlined scoping review will provide a summary of the current body of evidence on the use, effects and side-effects of buffered crystalloid solutions. This will provide an important update of the current evidence on the use, of "buffered" crystalloid solutions including evidence of potential benefits and harms.

A quality improvement initiative to increase the safety of pediatric emergency airway management

BACKGROUND

Emergency airway management is commonly associated with life-threatening hypoxia and hypotension which may be preventable.

AIMS

The aim of this quality improvement study was to reduce the frequency of intubation-related hypoxia and hypotension.

METHODS

This prospective quality improvement study was conducted over 4 years in the Emergency Department of The Royal Children's Hospital, Melbourne, Australia. A preintervention cohort highlighted safety gaps and was used to design study interventions, including an emergency airway algorithm, standardized airway equipment, a preintubation checklist and equipment template, endtidal carbon dioxide monitoring, postintubation team debriefing, and multidisciplinary team training. Following implementation, a postintervention cohort was used to monitor the impact of study interventions on clinical process and patient outcome. Process measures were as follows: use of a preintubation checklist, verbalization of an airway plan, adequate resuscitation prior to intubation, induction agent dose titration, use of apneic oxygenation, and use of endtidal carbon dioxide to confirm endotracheal tube position. The primary outcome measure was first pass success rate without hypoxia or hypotension. Potential harms from study interventions were monitored.

RESULTS

Forty-six intubations were included over one calendar year in the postintervention cohort (compared to 71 in the preintervention cohort). Overall clinical uptake of the 6 processes measures was 85%. First pass success rate without hypoxia or hypotension was 78% in the postintervention cohort compared with 49% in the preintervention cohort (absolute risk reduction: 29.0%; 95% confidence interval 12.3%-45.6%, number needed to treat: 3.5). No significant harms from study interventions were identified.

CONCLUSION

Quality improvement initiatives targeting emergency airway management may be successfully implemented in the emergency department and are associated with a reduction in adverse intubation-related events.

Chloride in intensive care units: a key electrolyte

Over the past few years, chloride has joined the league of essential electrolytes for critically ill patients. Dyschloremia can occur secondary to various etiologic factors before and during patient admission in the intensive care unit. Some cases are disease-related; others, treatment-related. Chloride abnormalities were shown in animal models to have adverse effects on arterial blood pressure, renal blood flow, and inflammatory markers, which have led to several clinical investigations. Hyperchloremia was studied in several settings and correlated to different outcomes, including death and acute kidney injury. Baseline hypochloremia, to a much lesser extent, has been studied and associated with similar outcomes. The chloride content of resuscitation fluids was also a subject of clinical research. In this review, we describe the effect of dyschloremia on outcomes in critically ill patients. We review the major studies assessing the chloride content of resuscitation fluids in the critically ill patient.

A Systematic Review of the Quality of IV Fluid Therapy in Veterinary Medicine

Objective

To evaluate the quality of the veterinary literature investigating IV fluid therapy in dogs, cats, horses, and cattle.

Design

Systematic review.

Procedures

The preferred reporting of items for systematic review and meta-analysis protocols (PRISMA-P) was employed for systematic review of all relevant IV fluid therapy manuscripts published from January 1969 through December 2016 in the Commonwealth Agricultural Bureaux International (CABI) database. Independent grading systems used to evaluate manuscripts included the updated CONsolidated Standards of Reporting Trials 2012 checklist, risk of bias for animal intervention studies, criteria for levels of evidence, and methodological quality (Jadad scale). The quality of articles published before and after 2010 was compared.

Results

One hundred and thirty-nine articles (63 dogs, 7 cats, 39 horses, 30 cattle) from 7,258 met the inclusion criteria. More than 50% of the manuscripts did not comply with minimal requirements for reporting randomized controlled trials. The most non-compliant items included identification of specific predefined objectives or a hypothesis, identification of trial design, how sample size was determined, randomization, and blinding procedures. Most studies were underpowered and at risk for selection, performance, and detection bias. The overall quality of the articles improved for articles published after 2010.

Conclusion and clinical relevance

Most of the veterinary literature investigating the administration of IV fluid therapy in dogs, cats, horses, and cattle is descriptive, does not comply with standards for evidence, or provide adequate translation to clinical practice. Authors should employ and journal editors should enforce international consensus recommendations and guidelines for publication of data from animal experiments investigating IV fluid therapy.

Balanced crystalloids for septic shock resuscitation

Timely fluid administration is crucial to maintain tissue perfusion in septic shock patients. However, the question concerning which fluid should be used for septic shock resuscitation remains a matter of debate. A growing body of evidence suggests that the type, amount and timing of fluid administration during the course of sepsis may affect patient outcomes. Crystalloids have been recommended as the first-line fluids for septic shock resuscitation. Nevertheless, given the inconclusive nature of the available literature, no definitive recommendations about the most appropriate crystalloid solution can be made. Resuscitation of septic and non-septic critically ill patients with unbalanced crystalloids, mainly 0.9% saline, has been associated with a higher incidence of acid-base balance and electrolyte disorders and might be associated with a higher incidence of acute kidney injury. This can result in greater demand for renal replacement therapy and increased mortality. Balanced crystalloids have been proposed as an alternative to unbalanced solutions in order to mitigate their detrimental effects. Nevertheless, the safety and effectiveness of balanced crystalloids for septic shock resuscitation need to be further addressed in a well-designed, multicenter, pragmatic, randomized controlled trial.

Fluid Resuscitation: Principles of Therapy and "Kidney Safe" Considerations

Fluid resuscitation in the acutely ill must take into consideration numerous elements, including the intravenous solution itself, the phase of resuscitation, and the strategies toward volume management which are paramount. With the advancement in the understanding and implementation of aggressive fluid resuscitation has also come a greater awareness of the resultant fluid toxicity, especially in those that suffer acute kidney injury, and the realization that there is continued ambiguity with regard to volume mitigation and removal in the resuscitated patient. As such, the discussion regarding intravenous solutions continues to evolve especially as it pertains to their effect on kidney and metabolic function, electrolytes, and ultimately patient outcome. In the section below, we review the foundations of fluid resuscitation in the critically ill patient and the different solutions available in this context, including their composition, physiologic properties, and safety and efficacy including the available data regarding "renal-safe" options.

The Ongoing Controversy: Crystalloids Versus Colloids

There is still much debate over the optimal fluid to use for resuscitation. Different studies have indicated either crystalloid or colloid is the ideal intravenous solution to administer, based on mortality or various physiological parameters. Older studies found differences between crystalloids and colloids. However, with the evolving science of fluid administration, more recent studies have shown no differences in patient outcomes. This review article will provide an overview of these substances and discuss the advantages, disadvantages, and implications for giving crystalloids and colloids in clinical practice.

Liberal perioperative fluid administration is an independent risk factor for morbidity and is associated with longer hospital stay after rectal cancer surgery

INTRODUCTION Recent studies have advocated the use of perioperative fluid restriction in patients undergoing major abdominal surgery as part of an enhanced recovery protocol. Series reported to date include a heterogenous group of high- and low-risk procedures but few studies have focused on rectal cancer surgery alone. The aim of this study was to assess the effects of perioperative fluid volumes on outcomes in patients undergoing elective rectal cancer resection. METHODS A prospectively maintained database of patients with rectal cancer who underwent elective surgery over a 2-year period was reviewed. Total volume of fluid received intraoperatively was calculated, as well as blood products required in the perioperative period. The primary outcome was postoperative morbidity (Clavien-Dindo grade I-IV) and the secondary outcomes were length of stay and major morbidity (Clavien-Dindo grade III-IV). RESULTS Over a 2-year period (2012-2013), 120 patients underwent elective surgery with curative intent for rectal cancer. Median total intraoperative fluid volume received was 3680ml (range 1200-9670ml); 65/120 (54.1%) had any complications, with 20/120 (16.6%) classified as major (Clavien-Dindo grade III-IV). Intraoperative volume >3500ml was an independent risk factor for the development of postoperative all-cause morbidity (P=0.02) and was associated with major morbidity (P=0.09). Intraoperative fluid volumes also correlated with length of hospital stay (Pearson's correlation coefficient 0.33; P<0.01). CONCLUSIONS Intraoperative fluid infusion volumes in excess of 3500ml are associated with increased morbidity and length of stay in patients undergoing elective surgery for rectal cancer.

Acute liver failure: An up-to-date approach

Acute liver failure is a rare but potentially devastating disease. Throughout the last few decades, acute liver failure outcomes have been improving in the context of the optimized overall management. This positive trend has been associated with the earlier recognition of this condition, the improvement of the intensive care unit management, and the developments in emergent liver transplantation. Accordingly, we aimed to review the current diagnostic and therapeutic approach to this syndrome, especially in the intensive care unit setting.

Acute kidney injury in the perioperative period and in intensive care units (excluding renal replacement therapies)

Acute kidney injury (AKI) is a syndrome that has progressed a great deal over the last 20 years. The decrease in urine output and the increase in classical renal biomarkers, such as blood urea nitrogen and serum creatinine, have largely been used as surrogate markers for decreased glomerular filtration rate (GFR), which defines AKI. However, using such markers of GFR as criteria for diagnosing AKI has several limits including the difficult diagnosis of non-organic AKI, also called "functional renal insufficiency" or "pre-renal insufficiency". This situation is characterized by an oliguria and an increase in creatininemia as a consequence of a reduction in renal blood flow related to systemic haemodynamic abnormalities. In this situation, "renal insufficiency" seems rather inappropriate as kidney function is not impaired. On the contrary, the kidney delivers an appropriate response aiming to recover optimal systemic physiological haemodynamic conditions. Considering the kidney as insufficient is erroneous because this suggests that it does not work correctly, whereas the opposite is occurring, because the kidney is healthy even in a threatening situation. With current definitions of AKI, normalization of volaemia is needed before defining AKI in order to avoid this pitfall.

Fluid replacement and respiratory function: comparison of whole blood with colloid and crystalloid: A randomised animal study

BACKGROUND

Fluid replacement with blood products, colloids and crystalloids is associated with morbidity and mortality. Despite this, the consequences of fluid administration on airway and respiratory tissue properties are not fully understood.

OBJECTIVE

Comparison of respiratory effects of fluid replacement with autologous blood (Group B), colloid (HES 6% 130/0.4, Group CO) or crystalloid solution (NaCl 0.9%, Group CR) after haemorrhage with separate assessments of airway resistance and respiratory tissue mechanics.

DESIGN

A randomised study.

SETTING

An experimental model of surgical haemorrhage and fluid replacement in rats.

PARTICIPANTS

Anaesthetised, ventilated rats randomly allocated into three groups (Group B: n = 8, Group CO: n = 8, Group CR: n = 9).

INTERVENTION

Animals were bled in six sequential steps, each manoeuvre targeting a loss of 5% of total blood volume. The blood loss was then replaced stepwise in a 1 : 1 ratio with one of the three fluids.

MAIN OUTCOME MEASURE

After each step, airway resistance (Raw), tissue damping and elastance (H) were determined by forced oscillations. Oedema indices from lung weights and histology were also measured.

RESULTS

Raw (mean ± SD) decreased in all groups following blood loss (-20.3 ± 9.5% vs. baseline, P < 0.05), and remained low following blood replacement (-21.7 ± 14.5% vs. baseline, P < 0.05), but was normalised by colloid (5.5 ± 10.7%, NS). Crystalloid administration exhibited an intermediate reversal effect (-8.4 ± 14.7%, NS). Tissue viscoelasticity increased following both blood loss and replacement, with no evidence of a significant difference in H between Groups CO and CR. More severe oedema was observed in Groups CR and CO than in Group B (P < 0.05), with no difference between the colloid and crystalloid solutions.

CONCLUSION

This model, which mimics surgical haemorrhage, yields no evidence of a difference between colloids and crystalloids with regard to the pulmonary consequences of blood volume restoration. Functional changes in the lung should not be a key concern when choosing fluid replacement therapy with these solutions.

Fluid resuscitation management in patients with burns: update

Since 1968, when Baxter and Shires developed the Parkland formula, little progress has been made in the field of fluid therapy for burn resuscitation, despite advances in haemodynamic monitoring, establishment of the 'goal-directed therapy' concept, and the development of new colloid and crystalloid solutions. Burn patients receive a larger amount of fluids in the first hours than any other trauma patients. Initial resuscitation is based on crystalloids because of the increased capillary permeability occurring during the first 24 h. After that time, some colloids, but not all, are accepted. Since the emergence of the Pharmacovigilance Risk Assessment Committee alert from the European Medicines Agency concerning hydroxyethyl starches, solutions containing this component are not recommended for burns. But the question is: what do we really know about fluid resuscitation in burns? To provide an answer, we carried out a non-systematic review to clarify how to quantify the amount of fluids needed, what the current evidence says about the available solutions, and which solution is the most appropriate for burn patients based on the available knowledge.

Fluid Composition and Clinical Effects

The range of intravenous fluids available for therapeutic use and the differing indications are diverse. A solid understanding of the composition of different types of fluids is essential to understanding the physiologic effects following administration and the appropriate clinical application. In this review, the authors describe the different fluids commonly available and discuss the potential benefits and harms depending on the clinical circumstances.

Acute kidney injury following cardiac surgery: current understanding and future directions

Acute kidney injury (AKI) complicates recovery from cardiac surgery in up to 30 % of patients, injures and impairs the function of the brain, lungs, and gut, and places patients at a 5-fold increased risk of death during hospitalization. Renal ischemia, reperfusion, inflammation, hemolysis, oxidative stress, cholesterol emboli, and toxins contribute to the development and progression of AKI. Preventive strategies are limited, but current evidence supports maintenance of renal perfusion and intravascular volume while avoiding venous congestion, administration of balanced salt as opposed to high-chloride intravenous fluids, and the avoidance or limitation of cardiopulmonary bypass exposure. AKI that requires renal replacement therapy occurs in 2–5 % of patients following cardiac surgery and is associated with 50 % mortality. For those who recover from renal replacement therapy or even mild AKI, progression to chronic kidney disease in the ensuing months and years is more likely than for those who do not develop AKI. Cardiac surgery continues to be a popular clinical model to evaluate novel therapeutics, off-label use of existing medications, and nonpharmacologic treatments for AKI, since cardiac surgery is fairly common, typically elective, provides a relatively standardized insult, and patients remain hospitalized and monitored following surgery. More efficient and time-sensitive methods to diagnose AKI are imperative to reduce this negative outcome. The discovery and validation of renal damage biomarkers should in time supplant creatinine-based criteria for the clinical diagnosis of AKI.

Postoperative management

Most patients undergoing major aortic surgery have multiple comorbidities and are at high risk of postoperative complications that affect multiple organ systems. Different aortic pathologies and surgical repair techniques have specific impact on the postoperative course. Ischemia-reperfusion injury is the common denominator in aortic surgery and influences the integrity of end-organ function. Common postoperative problems include hemodynamic instability due to the immediate inflammatory response, renal impairment, spinal cord ischemia, respiratory failure with prolonged mechanical ventilation, and gastrointestinal symptoms such as ileus or mesenteric ischemia. Focused care bundles to establish homeostasis and a team working toward an early functional recovery determine the success of effective rehabilitation and outcomes after aortic surgery.

Cost-effectiveness of Chloride-liberal versus Chloriderestrictive Intravenous Fluids among Patients Hospitalized in the United States

Background: Patients developing acute kidney injury (AKI) during critical illness or major surgery are at risk for renal sequelae such as costly and invasive acute renal replacement therapy (RRT) and chronic dialysis (CD). Rates of renal injury may be reduced with use of chloride-restrictive intravenous (IV) resuscitation fluids instead of chloride-liberal fluids. Objectives: To compare the cost-effectiveness of chloride-restrictive versus chloride-liberal crystalloid fluids used during fluid resuscitation or for the maintenance of hydration among patients hospitalized in the US for critical illnesses or major surgery. Methods: Clinical outcomes and costs for a simulated patient cohort (starting age 60 years) receiving either chloride-restrictive or chloride-liberal crystalloids were estimated using a decision tree for the first 90-day period after IV fluid initiation followed by a Markov model over the remainder of the cohort lifespan. Outcomes modeled in the decision tree were AKI development, recovery from AKI, progression to acute RRT, progression to CD, and death. Health states included in the Markov model were dialysis free without prior AKI, dialysis-free following AKI, CD, and death. Estimates of clinical parameters were taken from a recent meta-analysis, other published studies, and the US Renal Data System. Direct healthcare costs (in 2015 USD) were included for IV fluids, RRT, and CD. US-normalized health-state utilities were used to calculate quality-adjusted life years (QALYs). Results: In the cohort of 100 patients, AKI was predicted to develop in the first 90 days in 36 patients receiving chloride-liberal crystalloids versus 22 receiving chloride-restrictive crystalloids. Higher costs of chloride-restrictive crystalloids were offset by savings from avoided renal adverse events. Chloride-liberal crystalloids were dominant over chloride-restrictive crystalloids, gaining 93.5 life-years and 81.4 QALYs while saving $298 576 over the cohort lifespan. One-way sensitivity analyses indicated results were most sensitive to the relative risk for AKI development and relatively insensitive to fluid cost. In probabilistic sensitivity analyses with 1000 iterations, chloride-restrictive crystalloids were dominant in 94.7% of iterations, with incremental cost-effectiveness ratios below $50 000/QALY in 99.6%. Conclusions: This analysis predicts improved patient survival and fewer renal complications with chloriderestrictive IV fluids, yielding net savings versus chloride-liberal fluids. Results require confirmation in adequately powered head-to-head randomized trials.

Fluid resuscitation therapy for paediatric sepsis

Sepsis and septic shock are the final common pathway for many decompensated paediatric infections. Fluid resuscitation therapy has been the cornerstone of haemodynamic resuscitation in these children. Good evidence for equivalence between 0.9% saline and 4% albumin, with the relative expense of the latter, has meant that 0.9% saline is currently the most commonly used resuscitation fluid world-wide. Evidence for harm from the chloride load in 0.9% saline has generated interest in balanced solutions as first line resuscitation fluids. Their safety has been well established in observational studies, and they may well be the most reasonable default fluid for resuscitation. Semi-synthetic colloids have been associated with renal dysfunction and death and should be avoided. There is evidence for harm from excessive administration of any resuscitation fluid. Resuscitation fluid volumes should be treated in the same way as the dose of any other intravenously administered medication, and the potential benefits versus harms for the individual patient weighed prior to administration.

Fluid therapy and the hypovolemic microcirculation

PURPOSE OF REVIEW

In shock states, optimizing intravascular volume is crucial to promote an adequate oxygen delivery to the tissues. Our current practice in fluid management pivots on the Frank-Starling law of the heart, and the effects of fluids are measured according to the induced changes on stroke volume. The purpose of this review is to evaluate the boundaries of current macrohemodynamic approach to fluid administration, and to introduce the microcirculatory integration as a fundamental part of tissue perfusion monitoring.

RECENT FINDINGS

Macrocirculatory changes induced by volume expansion are not always coupled to proportional changes in microcirculatory perfusion. Loss of hemodynamic coherence limits the value of guiding fluid therapy according to macrohemodynamics, and highlights the importance of evaluating the ultimate target of volume administration, the microcirculation.

SUMMARY

Current approach to intravascular volume optimization is made from a macrohemodynamic perspective. However, several situations wherein macrocirculatory and microcirculatory coherence is lost have been described. Future clinical trials should explore the usefulness of integrating the microcirculatory evaluation in fluid optimization.

Clinical practice guide for the choice of perioperative volume-restoring fluid in adult patients undergoing non-cardiac surgery

The present Clinical practice guide responds to the clinical questions about security in the choice of fluid (crystalloid, colloid or hydroxyethyl starch 130) in patients who require volume replacement during perioperative period of non-cardiac surgeries. From the evidence summary, recommendations were made following the GRADE methodology. In this population fluid therapy based on crystalloids is suggested (weak recommendation, low quality evidence). In the events where volume replacement is not reached with crystalloids, the use of synthetic colloids (hydroxyethyl starch 130 or modified fluid gelatin) is suggested instead of 5% albumin (weak recommendation, low quality evidence). The choice and dosage of the colloid should be based in the product characteristics, patient comorbidity and anesthesiologist's experience.

Plasmalyte: No Longer a Culprit in Causing False-Positive Galactomannan Test Results

False-positive galactomannan (GM) results have been reported in patients treated with gluconate-containing solutions, such as Plasmalyte. The GM optical density index was tested on 33 distinct batches of Plasmalyte and was found to be negative in all of the batches, confirming that Plasmalyte is no longer a cause of false-positive GM results.

Principles of Fluid Management

Fluid therapy is the most common intervention received by acutely ill hospitalized patients; however, important questions on its optimal use remain. Its prescription should be patient and context specific, with clear indications and contradictions, and have the type, dose, and rate specified. Any fluid therapy, if provided inappropriately, can contribute unnecessary harm to patients. The quantitative toxicity of fluid therapy contributes to worse outcomes; this should prompt greater bedside attention to fluid prescription, fluid balance, development of avoidable complications attributable to fluid overload, and for the timely deresuscitation of patients whose clinical status and physiology allow active fluid mobilization.

Fluid type and the use of renal replacement therapy in sepsis: a systematic review and network meta-analysis

Fluid resuscitation, along with the early administration of antibiotics, is the cornerstone of treatment for patients with sepsis. However, whether differences in resuscitation fluids impact on the requirements for renal replacement therapy (RRT) remains unclear. To examine this issue, we performed a network meta-analysis (NMA), including direct and indirect comparisons, that addressed the effect of different resuscitation fluids on the use of RRT in patients with sepsis. The data sources MEDLINE, EMBASE, ACPJC, CINAHL and Cochrane Central Register were searched up to March 2014. Eligible studies included randomized trials reported in any language that enrolled adult patients with sepsis or septic shock and addressed the use of RRT associated with alternative resuscitation fluids. The risk of bias for individual studies and the overall certainty of the evidence were assessed. Ten studies (6664 patients) that included a total of nine direct comparisons were assessed. NMA at the four-node level showed that an increased risk of receiving RRT was associated with fluid resuscitation with starch versus crystalloid [odds ratio (OR) 1.39, 95% credibility interval (CrI) 1.17-1.66, high certainty]. The data suggested no difference between fluid resuscitation with albumin and crystalloid (OR 1.04, 95% CrI 0.78-1.38, moderate certainty) or starch (OR 0.74, 95% CrI 0.53-1.04, low certainty). NMA at the six-node level showed a decreased risk of receiving RRT with balanced crystalloid compared to heavy starch (OR 0.50, 95% CrI 0.34-0.74, moderate certainty) or light starch (OR 0.70, 95% CrI 0.49-0.99, high certainty). There was no significant difference between balanced crystalloid and saline (OR 0.85, 95% CrI 0.56-1.30, low certainty) or albumin (OR 0.82, 95% CrI 0.49-1.37, low certainty). Of note, these trials vary in terms of case mix, fluids evaluated, duration of fluid exposure and risk of bias. Imprecise estimates contributed to low confidence in most estimates of effect. Among the patients with sepsis, fluid resuscitation with crystalloids compared to starch resulted in reduced use of RRT; the same may be true for albumin versus starch.