Fluids are drugs: type, dose and toxicity. Curr Opin Crit Care. 2013;19:290-298. [PMID: 23817025 DOI: 10.1097/mcc.0b013e3283632d77]

Assessment of the components of fluid balance in patients with septic shock: a prospective observational study

BACKGROUND

The optimal amount for initial fluid resuscitation is still controversial in sepsis and the contribution of non-resuscitation fluids in fluid balance is unclear. We aimed to investigate the main components of fluid intake and fluid balance in both survivors and non-survivor patients with septic shock within the first 72 hours.

METHODS

In this prospective observational study in two intensive care units, we recorded all fluids administered intravenously, orally, or enterally, and losses during specific time intervals from vasopressor initiation: T1 (up to 24 hours), T2 (24 to 48 hours) and T3 (48 to 72 hours). Logistic regression and a mathematical model assessed the association with mortality and the influence of severity of illness.

RESULTS

We included 139 patients. The main components of fluid intake varied across different time intervals, with resuscitation and non-resuscitation fluids such as antimicrobials and maintenance fluids being significant contributors in T1 and nutritional therapy in T2/T3. A positive fluid balance both in T1 and T2 was associated with mortality (p = 0.049; p = 0.003), while nutritional support in T2 was associated with lower mortality (p = 0.040). The association with mortality was not explained by severity of illness scores.

CONCLUSIONS

Non-resuscitation fluids are major contributors to a positive fluid balance within the first 48 hours of resuscitation. A positive fluid balance in the first 24 and 48 hours seems to independently increase the risk of death, while higher amount of nutrition seems protective. This data might inform fluid stewardship strategies aiming to improve outcomes and minimize complications in sepsis.

Intravenous fluid therapy: a multi-national, cross-sectional survey of common medical student resources

BACKGROUND

Inappropriate prescription of intravenous fluid therapy is highly prevalent in hospitals, with up to 1 in 5 patients suffering from preventable, additional morbidity. Since trainee physicians are frequently responsible for prescribing intravenous fluids, it is possible that common medical student resources do not sufficiently cover the topic. There is a paucity of recent literature on this issue, which this study was designed to address.

METHODS

Two original evaluation tools were created by the authors to evaluate reference books, official guidelines, and online reference sources commonly used by medical students in the United States of America, Australia, and the United Kingdom on their coverage of foundational and clinically relevant principles of intravenous fluid prescription. The choice of student resources was guided by a literature search and personal experience. A total of 10 resources was assessed.

RESULTS

Resources were generally deficit in their coverage of basic intravenous fluid topics. The total points each topic accumulated ranged from 0.5 (5%) to 7.5 (75%), with the median score being 4.5 (45%), on a scale from 0 to 10 points.

CONCLUSIONS

Popular medical student resources poorly cover intravenous fluid therapy topics. This may be contributing to inadequate fluid prescribing practices.

Accuracy of cumulative volumes of fluid challenge to assess fluid responsiveness in critically ill patients with acute circulatory failure: a pharmacodynamic approach

BACKGROUND

The relationship between the dose (volume of fluid) and the effect (increase of stroke volume [SV]) has been poorly described. We hypothesised that the analysis of the dynamic response of SV during fluid challenge (FC) helps to determine the optimal volume of FC, along with its diagnostic accuracy parameters for fluid responsiveness.

METHODS

A prospective observational study was conducted in critically ill patients with circulatory failure. Patients monitored with oesophageal Doppler and assigned to an FC of 500 ml of crystalloid were included. The areas under the curve (AUC) and 95% confidence intervals (CI₉₅) of the receiver operating characteristic curves for cumulative volumes from 50 to 450 ml were determined for fluid responsiveness (SV increase ≥15% from baseline) along with other parameters of diagnostic accuracy. In the pharmacodynamic analysis, dose-effect and dose-response models were constructed, with determination of median and 90% effective dose (ED₅₀ and ED₉₀).

RESULTS

Forty-five patients were included. The AUC increased with cumulative volumes of FC up to 250 ml (AUC₂₅₀ 0.93 [CI₉₅: 0.85-1.00]), followed by a plateau above 0.95 of AUC. The optimal volume was 250 ml, associated with a specificity of 0.89 [CI₉₅: 0.78-1.00], a sensitivity of 0.92 [CI₉₅: 0.69-1.00], and a threshold of 9.6% increase in SV. The ED₅₀ was 156 [CI₉₅: 136-177] ml and the ED₉₀ was 312 [CI₉₅: 269-352] ml.

CONCLUSIONS

A volume of FC of 250 ml with a threshold of 9.6% increase in SV showed the highest accuracy in detecting fluid responsiveness in critically ill patients with shock.

CLINICAL TRIAL REGISTRATION

.

A Multicenter, Open-Label, Randomized Controlled Trial of a Conservative Fluid Management Strategy Compared With Usual Care in Participants After Cardiac Surgery: The Fluids After Bypass Study

OBJECTIVES

There is little evidence to guide fluid administration to patients admitted to the ICU following cardiac surgery. This study aimed to determine if a protocolized strategy known to reduce fluid administration when compared with usual care reduced ICU length of stay following cardiac surgery.

DESIGN

Prospective, multicenter, parallel-group, randomized clinical trial.

SETTING

Five cardiac surgical centers in New Zealand conducted from November 2016 to December 2018 with final follow-up completed in July 2019.

PATIENTS

Seven-hundred fifteen patients undergoing cardiac surgery; 358 intervention and 357 usual care.

INTERVENTIONS

Randomization to protocol-guided strategy utilizing stroke volume variation to guide administration of bolus fluid or usual care fluid administration until desedation or up to 24 hours. Primary outcome was length of stay in ICU. Organ dysfunction, mortality, process of care measures, patient-reported quality of life, and disability-free survival were collected up to day 180.

MEASUREMENTS AND MAIN RESULTS

Overall 666 of 715 (93.1%) received at least one fluid bolus. Patients in the intervention group received less bolus fluid (median [interquartile range], 1,000 mL [250-2,000 mL] vs 1,500 mL [500-2,500 mL]; p < 0.0001) and had a lower overall fluid balance (median [interquartile range], 319 mL [-284 to 1,274 mL] vs 673 mL [38-1,641 mL]; p < 0.0001) in the intervention period. There was no difference in ICU length of stay between the two groups (27.9 hr [21.8-53.5 hr] vs 25.6 hr [21.9-64.6 hr]; p = 0.95). There were no differences seen in development of organ dysfunction, quality of life, or disability-free survival at any time points. Hospital mortality was higher in the intervention group (4% vs 1.4%; p = 0.04).

CONCLUSIONS

A protocol-guided strategy utilizing stroke volume variation to guide administration of bolus fluid when compared with usual care until desedation or up to 24 hours reduced the amount of fluid administered but did not reduce the length of stay in ICU.

Understanding Volume Kinetics: The Role of Pharmacokinetic Modeling and Analysis in Fluid Therapy

Fluid therapy is a rapidly evolving yet imprecise clinical practice based upon broad assumptions, species-to-species extrapolations, obsolete experimental evidence, and individual preferences. Although widely recognized as a mainstay therapy in human and veterinary medicine, fluid therapy is not always benign and can cause significant harm through fluid overload, which increases patient morbidity and mortality. As with other pharmaceutical substances, fluids exert physiological effects when introduced into the body and therefore should be considered as "drugs." In human medicine, an innovative adaptation of pharmacokinetic analysis for intravenous fluids known as volume kinetics using serial hemoglobin dilution and urine output has been developed, refined, and investigated extensively for over two decades. Intravenous fluids can now be studied like pharmaceutical drugs, leading to improved understanding of their distribution, elimination, volume effect, efficacy, and half-life (duration of effect) under various physiologic conditions, making evidence-based approaches to fluid therapy possible. This review article introduces the basic concepts of volume kinetics, its current use in human and animal research, as well as its potential and limitations as a research tool for fluid therapy research in veterinary medicine. With limited evidence to support our current fluid administration practices in veterinary medicine, a greater understanding of volume kinetics and body water physiology in veterinary species would ideally provide some evidence-based support for safer and more effective intravenous fluid prescriptions in veterinary patients.

Evaluation of the Distribution and Elimination of Balanced Isotonic Crystalloid, 5% Hypertonic Saline, and 6% Tetrastarch 130/0.4 Using Volume Kinetic Modeling and Analysis in Healthy Conscious Cats

This prospective, randomized, blinded, interventional cross-over study investigated the distribution, elimination, plasma volume expansion, half-life, comparative potency, and ideal fluid prescription of three commonly prescribed intravenous (IV) fluids in 10 healthy conscious cats using volume kinetic analysis that is novel to veterinary medicine. Each cat received 20 mL/kg of balanced isotonic crystalloid (PLA), 3.3 mL/kg of 5% hypertonic saline (HS), and 5 mL/kg of 6% tetrastarch 130/0.4 (HES) over 15 min on separate occasions. Hemoglobin concentration, red blood cell count, hematocrit, heart rate, and blood pressure were measured at baseline, 5, 10, 15, 20, 30, 40, 50, 60, and every 15 min until 180 min. Urine output was estimated every 30 min using point-of-care bladder ultrasonography. Plasma dilution derived from serial hemoglobin concentration and red blood cell count served as input variables for group and individual fluid volume kinetic analyses using a non-linear mixed effects model. In general, the distribution of all IV fluids was rapid, while elimination was slow. The half-lives of PLA, HS, and HES were 49, 319, and 104 min, respectively. The prescribed fluid doses for PLA, HS, and HES resulted in similar peak plasma volume expansion of 27–30%. The potency of HS was 6 times higher than PLA and 1.7 times greater than HES, while HES was 3.5 times more potent than PLA. Simulation of ideal fluid prescriptions to achieve and maintain 15 or 30% plasma volume expansion revealed the importance of a substantial reduction in infusion rates following initial IV fluid bolus. In conclusion, volume kinetic analysis is a feasible research tool that can provide data on IV fluid kinetics and body water physiology in cats. The rapid distribution but slow elimination of IV fluids in healthy conscious cats is consistent with anecdotal reports of fluid overload susceptibility in cats and warrants further investigation.

Early fluid overload was associated with prolonged mechanical ventilation and more aggressive parameters in critically ill paediatric patients

AIM

We evaluated the influence of early fluid overload on critically ill children admitted to a paediatric intensive care unit by examining mechanical ventilation (MV), mortality, length of stay and renal replacement therapy.

METHODS

This retrospective cohort study covered January 2015 to December 2016 and focused on all episodes of MV support that exceeded 24 hours. The fluid overload percentage (FO%) was calculated daily for the first 72 hours and we estimated its effect on outcomes.

RESULTS

We included 186 MV episodes in 154 patients. The median age was 13.8 months, with an interquartile range (IQR) of 3.8-34.0 months, and the mortality rate was 12.4%. The median FO% in the first 72 hours was 8.0% (IQR 3.6%-11.2%). An FO% of ≥10% was associated with higher ventilatory parameters, namely peak inspiratory pressure (P = .023) and positive end expiratory pressure (P = .003), and renal replacement therapy (P = .02) and higher mortality (8.8% vs 19.7%). In a multivariate Cox regression model, FO ≥ 10% at 72 hours was independently associated with longer MV support, but not mortality (P = .001).

CONCLUSION

In a heterogeneous paediatric population given MV, an early cumulative FO of ≥10% was associated with more aggressive ventilatory parameters and prolonged length of MV, but not mortality.

Collaborative Management Strategies for Drug Shortages in Neurocritical Care

Drug shortages have become all too familiar in the health care environment, with over 200 drugs currently on shortage. In the wake of Hurricane Maria in September 2017, hospitals across the USA had to quickly and creatively adjust medication preparation and administration techniques in light of decreased availability of intravenous (IV) bags used for compounding a vast amount of medications. Amino acid preparations, essential for compounding parenteral nutrition, were also directly impacted by the hurricane. Upon realization of the impending drug shortages, hospitals resorted to alternative methods of drug administration, such as IV push routes, formulary substitutions, or alternative drug therapies in hopes of preserving the small supply of IV bags available and prioritizing them for them most critical needs. In some cases, alternative drug therapies were required, which increased the risk of medication errors due to the use of less-familiar treatment options. Clinical pharmacists rounding with medical teams provided essential, patient-specific drug regimen alternatives to help preserve a dwindling supply while ensuring use in the most critical cases. Drug shortages also frequently occur in the setting of manufacturing delays or discontinuation and drug recalls, with potential to negatively impact patient care. The seriousness of the drug shortage crisis reached public attention by December 2017, when political and pharmacy organizations called for response to the national drug shortage crisis. In this article, we review institutional mitigation strategies in response to drug shortages and discuss downstream effects of these shortages, focusing on medications commonly prescribed in neurocritical care patients.

The effects of Plasma-Lyte 148 solution on blood coagulation: an in-vitro, volunteer study using rotational thromboelastometry

The current study aimed to measure the effects of Plasma-Lyte 148 solution on the blood coagulation profile according to the hemodilution level using rotational thromboelastometry (ROTEM) tests. Venous blood was collected from 12 healthy volunteers and divided into four specimen bottles, which were diluted at different levels with Plasma-Lyte 148 (0, 20, 40, and 60%). Following this, ROTEM tests were performed on the study samples. We found that as the hemodilution level increased, the ROTEM values showed a hypocoagulable pattern. The change rate of the maximum clot firmness (MCF) of INTEM was greater in the 40 (P = 0.015) and 60% (P < 0.001) dilutions than it was in the 20% dilution. Greater lengthening of the clot formation time of EXTEM was observed in the 60% dilution than it was in the 20% dilution (P < 0.001). The alpha-angle of EXTEM showed a greater decrease in the 60% dilution than it did in the 20% dilution (P < 0.001). A larger change rate of the MCF of EXTEM was observed in the 40 (P = 0.003) and 60% (P < 0.001) dilutions than it was in the 20% dilution. A greater decrease in the MCF of FIBTEM was identified in the 40 (P = 0.009) and 60% (P < 0.001) dilutions than in the 20% dilution. All coagulation pathways exhibited hypocoagulable patterns as the hemodilution level increased. However, most of the mean values of ROTEM parameters were within the normal reference range, except for those of the 60% dilution.

Fluid resuscitation for acute kidney injury: an empty promise

PURPOSE OF REVIEW

The past decade has seen more advances in our understanding of fluid therapy than the preceding decades combined. What was once thought to be a relatively benign panacea is increasingly being recognized as a potent pharmacological and physiological intervention that may pose as much harm as benefit.

RECENT FINDINGS

Recent studies have clearly indicated that the amount, type, and timing of fluid administration have profound effects on patient morbidity and outcomes. The practice of aggressive volume resuscitation for 'renal protection' and 'hemodynamic support' may in fact be contributing to end organ dysfunction. The practice of early goal-directed therapy for patients suffering from critical illness or undergoing surgery appears to offer no benefit over conventional therapy and may in fact be harmful. A new conceptual model for fluid resuscitation of critically ill patients has recently been developed and is explored here.

SUMMARY

The practice of giving more fluid early and often is being replaced with new conceptual models of fluid resuscitation that suggest fluid therapy be 'personalized' to individual patient pathophysiology.

Choice of Fluid Therapy in the Initial Management of Sepsis, Severe Sepsis, and Septic Shock

Sepsis results in disruption of the endothelial glycocalyx layer and damage to the microvasculature, resulting in interstitial accumulation of fluid and subsequently edema. Fluid resuscitation is a mainstay in the initial treatment of sepsis, but the choice of fluid is unclear. The ideal resuscitative fluid is one that restores intravascular volume while minimizing edema; unfortunately, edema and edema-related complications are common consequences of current resuscitation strategies. Crystalloids are recommended as first-line therapy, but the type of crystalloid is not specified. There is increasing evidence that normal saline is associated with increased mortality and kidney injury; balanced crystalloids may be a safer alternative. Albumin is similar to crystalloids in terms of outcomes in the septic population but is costlier. Hydroxyethyl starches appear to increase mortality and kidney injury in the critically ill and are no longer indicated in these patients. In the trauma population, the shift to plasma-based resuscitation with decreased use of crystalloid and colloid in the treatment of hemorrhagic shock has led to decreased inflammatory and edema-mediated complications. Studies are needed to determine if these benefits also occur with a similar resuscitation strategy in the setting of sepsis.

Learning to prescribe intravenous fluids: A scoping review

INTRODUCTION

Prescribing intravenous (IV) fluid therapy is a core skill expected of qualified doctors at the point of graduation, but medical graduates often feel ill-equipped to perform this task. This lack of preparedness contributes to treatment-related patient harm. This scoping review maps the current state of published evidence about how junior doctors prescribe IV fluid therapy and learn how to do it.

METHODS

We searched five electronic databases and grey literature from 1994 until June 2016 for articles describing any aspect of IV fluid prescribing practice or its education. A total of 63 articles were selected for analysis. Using the WHO Guide to Good Prescribing to categorize the extracted findings, our review focuses on prescribing IV fluids in adult generalist settings.

RESULTS

Most articles studied IV fluid prescribing from the perspective of the doctor. Junior clinicians struggled to conceptualize IV fluid prescribing as a 'whole task' in authentic work settings and lacked support. Educational interventions to improve IV fluid prescribing often focused on enhancing prescriber knowledge about fluid and electrolyte balance rather than execution of the prescribing task.

CONCLUSIONS

Our understanding of IV fluid prescribing as a holistic integrated skill is patchy, as is its performance. Current IV fluid prescribing education appears insufficient to foster safe and effective practice. For education to achieve the ultimate goal of safer prescribing in workplaces, we need a clearer understanding of how healthcare professionals prescribe IV fluids in real world practice.

The dose of hydroxyethyl starch 6% 130/0.4 for fluid therapy and the incidence of acute kidney injury after cardiac surgery: A retrospective matched study

The safety of hydroxyethyl starches (HES) is still under debate. No studies have compared different dosing regimens of HES in cardiac surgery. We analyzed whether the incidence of Acute Kidney Injury (AKI) differed taking into account a weight-adjusted cumulative dose of HES 6% 130/0.4 for perioperative fluid therapy. This retrospective cohort study included all adult patients undergoing elective or emergency cardiac surgery with or without cardiopulmonary bypass. Exclusion criteria were patients on renal replacement therapy (RRT), cardiac trauma surgery, heart transplantation, patients with ventricular assist devices, subjects who required a surgical revision for bleeding and those whose medical records were incomplete. Primary endpoint was AKI following the creatinine based RIFLE classification. Secondary endpoints were 30-day mortality and RRT. Patients were divided into 2 groups whether they had received a cumulative HES dose of < 30 mL/kg (Low HES) or ≥ 30 mL/kg (High HES) during the intra- and postoperative period. A total of 1501 patients were analyzed with 983 patients in the Low HES and 518 subjects in the High HES group. 185 (18.8%) patients in the Low HES and 119 (23.0%) patients in the High HES group developed AKI (P = 0.06). In multivariable regression analysis the dose of HES administered per weight was not associated with AKI. After case-control matching 217 patients were analyzed in each group. AKI occurred in 39 (18.0%) patients in the Low HES and 50 (23.0%) patients in the High HES group (P = 0.19). In conditional regression analysis performed on the matched groups a lower weight-adjusted dose of HES was significantly associated with a reduced incidence of AKI [(Odds Ratio (95% CI) = 0.825 (0.727-0.936); P = 0.003]. In the absence of any safety study the cumulative dose of modern HES in cardiac surgery should be kept less than 30 mL/kg.

Effect of Intravenously Administered Crystalloid Solutions on Acid-Base Balance in Domestic Animals

Intravenous fluid therapy can alter plasma acid-base balance. The Stewart approach to acid-base balance is uniquely suited to identify and quantify the effects of the cationic and anionic constituents of crystalloid solutions on plasma pH. The plasma strong ion difference (SID) and weak acid concentrations are similar to those of the administered fluid, more so at higher administration rates and with larger volumes. A crystalloid's in vivo effects on plasma pH are described by 3 general rules: SID > [HCO3-] increases plasma pH (alkalosis); SID < [HCO3-] decreases plasma pH (alkalosis); and SID = [HCO3-] yields no change in plasma pH. The in vitro pH of commercially prepared crystalloid solutions has little to no effect on plasma pH because of their low titratable acidity. Appreciation of IV fluid composition and an understanding of basic physicochemical principles provide therapeutically valuable insights about how and why fluid therapy can produce and correct alterations of plasma acid-base equilibrium. The ideal balanced crystalloid should (1) contain species-specific concentrations of key electrolytes (Na+ , Cl- , K+ , Ca++ , Mg++ ), particularly Na+ and Cl- ; (2) maintain or normalize acid-base balance (provide an appropriate SID); and (3) be isosmotic and isotonic (not induce inappropriate fluid shifts) with normal plasma.

Fluids in Sepsis and Septic Shock (FISSH): protocol for a pilot randomised controlled trial

INTRODUCTION

Observational evidence suggests physiological benefits and lower mortality with lower chloride solutions; however, 0.9% saline remains the most widely used fluid worldwide. Given uncertainty regarding the association of lower chloride on mortality, it is unlikely that practice will change without direct randomised clinical trial (RCT) evidence. This pilot RCT will investigate the feasibility of a large-scale trial directly comparing low chloride with high chloride fluids in patients with septic shock.

METHODS AND ANALYSIS

This is a randomised, concealed, blinded parallel-group multicentre pilot trial. We will include adult critically ill patients with septic shock, defined as ongoing hypotension despite 1 L of fluid, or a serum lactate >4 mmol/L, who are within 6 hours of hospital presentation or rapid response team activation. We will exclude patients if they have an aetiology of shock other than sepsis, if they have acute burn injury, elevated intracranial pressure, intent to withdraw life support or previous enrolment in this or a competing trial. Following informed consent, patients will be randomised to a low chloride fluid strategy or a high chloride fluid strategy for the duration of their ICU stay or until 30 days postrandomisation. Clinicians, patients, families and research staff will be blinded. The primary outcome for this trial will be feasibility, assessed by consent rate, recruitment success and protocol adherence. Patient-important clinical outcomes include mortality, receipt of renal replacement therapy, intensive care unit and hospital lengths of stay and surrogate outcomes of incidence of acidosis, hyperkalaemia and acute kidney injury.

ETHICS AND DISSEMINATION

This pilot trial will test the feasibility of conducting the main trial, which will examine the effect of high versus low chloride fluids in patients with septic shock on patient-important outcomes.

TRIAL REGISTRATION NUMBER

NCT02748382, registered 8 April 2016.

PROTOCOL DATE

1 July 2016.

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.

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.

Is the "golden age" of the "golden hour" in sepsis over?

The so-called “golden hour” of trauma resuscitation has been applied to a number of disease conditions in the intensive care unit (ICU) setting. For example, the “golden hour” as applied to the treatment of critically children and adults with severe sepsis and septic shock is based upon early recognition, early administration of antibiotics, and early reversal of the shock state. However, several clinical studies published over the last decade have called into question this time-honored approach and suggest that overly aggressive fluid resuscitation may cause more harm than good. Perhaps we are finally leaving the “Golden Age” of the “golden hour” and entering a new age in which we are able to use a more personalized approach to fluid management for patients with severe sepsis/septic shock.

Fluid management in abdominal surgery: what, when, and when not to administer

The entire team (including anesthesiologists, surgeons, and intensive care physicians) must work together (before, during, and after abdominal surgery) to determine the optimal amount (quantity) and type (quality) of fluid necessary in the perioperative period. The authors present an overview of the basic principles that underlie fluid management, including evidence-based recommendations (where tenable) and a rational approach for when and what to administer.

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.

The effect of 0.9% saline versus plasmalyte on coagulation in patients undergoing lumbar spinal surgery; a randomized controlled trial

INTRODUCTION

In multi-level lumbar spinal fusion surgery yielding a large amount of blood loss, choice of fluid for volume resuscitation is an important issue since it can influence acid-base status, coagulation, and patients' outcome. This study compared the effect of plasmalyte to 0.9% saline on coagulation assessed by rotation thromboelastometry (ROTEM) and acid-base balance in the aforementioned patients.

METHODS

Fifty patients were randomly allocated to receive either 0.9% saline or plasmalyte during operation and until postoperative 12 h. ROTEM was performed at 10 min after anesthetic induction and end of surgery. Arterial blood gas analyses were serially performed from 10 min after anesthetic induction until postoperative 12 h. Fluid balance, blood loss, and transfusion requirement were assessed.

RESULTS

ROTEM variables showed sporadic deterioration in both groups after surgery without intergroup differences. Intraoperatively, arterial pH, base excess, and bicarbonate concentrations were lower and serum chloride concentrations were higher in the 0.9% saline group compared with the plasmalyte group. The differences in base excess and bicarbonate concentrations persisted until postoperative 12 h. Fluid balance, blood loss, and transfusion requirement were similar between the groups while urine output was greater in the plasmalyte group compared with the 0.9% saline group (3.2 ± 1.6 ml/kg/h vs. 1.8 ± 1.1 ml/kg/h, p = 0.001).

CONCLUSION

In contrast to plasmalyte, fluid therapy with 0.9% saline resulted in transient hyperchloremic acidosis in patients undergoing multi-level lumbar spinal fusion, while coagulation assessed by ROTEM analysis and the amount of blood loss were similar between the groups.

The year in cardiothoracic and vascular anesthesia: selected highlights from 2013

This article reviewed selected research highlights of 2013 that pertain to the specialty of cardiothoracic and vascular anesthesia. The first major theme is the commemoration of the sixtieth anniversary of the first successful cardiac surgical procedure with cardiopulmonary bypass conducted by Dr Gibbon. This major milestone revolutionized the practice of cardiovascular surgery and invigorated a paradigm of mechanical platforms for contemporary perioperative cardiovascular practice. Dr Kolff was also a leading contributor in this area because of his important contributions to the refinement of cardiopulmonary bypass and mechanical ventricular assistance. The second major theme is the diffusion of echocardiography throughout perioperative practice. There are now guidelines and training pathways to guide its generalization into everyday practice. The third major theme is the paradigm shift in perioperative fluid management. Recent large randomized trials suggest that fluids are drugs that require a precise prescription with respect to type, dose, and duration. The final theme is patient safety in the cardiac perioperative environment. A recent expert scientific statement has focused attention on this issue because most perioperative errors are preventable. It is likely that clinical research in this area will blossom because this is a major opportunity for improvement in our specialty. The patient care processes identified in these research highlights will further improve perioperative outcomes for our patients.

Consensus recommendations for standard therapy of glomerular disease in dogs

Standard therapy forms the basic foundation for care of dogs with glomerular disease, as it is herein recommended for use in all affected animals regardless of causation of the disease. Consensus recommendations target the evaluation and management of proteinuria, inhibition of the renin-angiotensin-aldosterone system, modification in dietary intake with special consideration for those nutrients with renal effects, diagnosis and treatment of systemic hypertension, and evaluation and management of body fluid volume status in dogs with glomerular disease.

Intravenous fluids in sepsis: what to use and what to avoid

PURPOSE OF REVIEW

Septic shock is one of the most common and life-threatening conditions afflicting critically ill patients. Intravenous volume resuscitation is considered an initial and very important step in management. The most suitable fluid for volume expansion during septic shock remains unclear. In this review, we focus on the benefits and adverse effects of the most commonly used intravenous fluids in critically ill septic patients.

RECENT FINDINGS

The debate about the benefits of colloids over crystalloids has been ongoing for the last few decades. With recent literature showing apparent harm from the use of hydroxyethyl starches (HESs), and given the growing concerns of adverse renal and acid-base abnormalities associated with 0.9% saline compared with balanced crystalloid solutions, it may be time to change the nature of the 'fluid debate'.

SUMMARY

Crystalloids should still be considered as the first-choice drug for volume resuscitation in patients with septic shock. Colloids such as albumin can be considered in some clinical settings. HES should be avoided. Balanced crystalloids might have an important role to play in the management of septic shock.

Albumin—Beyond Fluid Replacement in Cardiopulmonary Bypass Surgery

Maintaining vascular barrier competence, preventing interstitial edema, and keeping microcirculation intact is crucial to achieve an optimal outcome in cardiopulmonary bypass surgery (CPB). Blood contact with roller pumps and foreign surfaces during CPB induces shear stress and a pressure drop across the pump boot that leads to transient systemic activation of the inflammatory and hemostatic systems. Moreover, patients after CPB often need volume resuscitation using the smallest possible amount of colloid solution because of fluid overload. For this purpose, human-derived albumin may be preferred over synthetic colloids because CPB priming with albumin preserves oncotic pressure, prevents platelet adhesion, and likely induces less consumption of coagulation factors. In patients with increased bleeding or renal failure, albumin is a safe alternative because of its minimal side effects. Large, randomized clinical trials comparing the benefit of albumin versus other fluids are warranted in the future to define albumin’s distinct role in select high-risk surgical populations.

Respiratory rate at intensive care unit discharge after liver transplant is an independent risk factor for intensive care unit readmission within the same hospital stay: a nested case-control study

PURPOSE

Intensive care unit (ICU) readmission negatively impacts patients' outcomes. We aimed to characterize and determine risk factors for ICU readmission within the initial hospital stay after liver transplant (LT).

MATERIALS AND METHODS

The reference cohort included 369 LT recipients from a Canadian center between 2005 and 2012. One control was randomly selected per each case of ICU readmission within the initial hospital stay after LT. Survival analysis used the Kaplan-Meier method. Associations were studied by conditional logistic regression.

RESULTS

Fifty-two (14%) LT recipients were readmitted to the ICU within the initial hospital stay after LT; they had longer first hospital stay (P < .001) and lower 1-month to 2-year cumulative survival (P < .001). Respiratory failure was the major cause of ICU readmission (61%). Respiratory rate at discharge from the first ICU stay after LT was an independent risk factor for ICU readmission (odds ratio = 1.24). The cutoff point more than 20 breaths per minute prognosticated ICU readmission with a specificity of 90% and a positive predictive value of 80%.

CONCLUSIONS

Intensive care unit readmission within the initial hospital stay after LT negatively impacts LT recipients' outcomes. Monitoring respiratory rate at discharge from the first ICU stay after LT is important to prevent readmission.

Controversies in fluid therapy: Type, dose and toxicity

Fluid therapy is perhaps the most common intervention received by acutely ill hospitalized patients; however, a number of critical questions on the efficacy and safety of the type and dose remain. In this review, recent insights derived from randomized trials in terms of fluid type, dose and toxicity are discussed. We contend that the prescription of fluid therapy is context-specific and that any fluid can be harmful if administered inappropriately. When contrasting ‘‘crystalloid vs colloid’’, differences in efficacy are modest but differences in safety are significant. Differences in chloride load and strong ion difference across solutions appear to be clinically important. Phases of fluid therapy in acutely ill patients are recognized, including acute resuscitation, maintaining homeostasis, and recovery phases. Quantitative toxicity (fluid overload) is associated with adverse outcomes and can be mitigated when fluid therapy based on functional hemodynamic parameters that predict volume responsiveness and minimization of non-essential fluid. Qualitative toxicity (fluid type), in particular for iatrogenic acute kidney injury and metabolic acidosis, remain a concern for synthetic colloids and isotonic saline, respectively. Physiologically balanced crystalloids may be the ‘‘default’’ fluid for acutely ill patients and the role for colloids, in particular hydroxyethyl starch, is increasingly unclear. We contend the prescription of fluid therapy is analogous to the prescription of any drug used in critically ill patients.