Intravenous 0.9% Saline and General Surgical Patients: A problem, Not a Solution

Effect of intraoperative fluid type on postoperative systemic inflammatory response and end organ dysfunction following total pancreatectomy with islet autotransplantation in children

PURPOSE

To evaluate the effect of intraoperative fluid type [half normal saline (0.45NS) or lactated Ringer's solution (LR)] on the risk of systemic inflammatory response syndrome (SIRS) and acute kidney injury after total pancreatectomy with islet autotransplantation in children.

METHODS

Retrospective review where demographics, operative details, systemic inflammatory response, and evaluation for end organ dysfunction over the first 5 postoperative days was obtained. Mixed effects Poisson regression compared risk of SIRS and acute kidney injury by intraoperative fluid type.

RESULTS

Forty three patients were included with no difference in demographic characteristics between groups. SIRS was observed in 95, 77, and 71% over post operative days 1, 3, and 5. Intraoperative fluid type was found to not be associated with postoperative SIRS (RR: 0.91, p = 0.23). However, female sex (RR: 1.30, p < 0.01), increased BMI (RR: 1.08, p < 0.01), and longer operative time (RR: 1.07, p < 0.01) were found to be factors that are associated with increased risk of postoperative SIRS. Intraoperative 0.45NS use was associated with increased acute kidney injury compared to LR on postoperative day 1 (52% vs 0%, p < 0.01), but not on postoperative days 3 or 5.

CONCLUSION

Intraoperative fluid type (0.45NS vs LR) does not increase the risk of postoperative SIRS in children after TPIAT. Predictive factors that are associated with an increased risk of eliciting postoperative SIRS includes female sex, increased BMI, and longer operative times.

LEVEL OF EVIDENCE

III.

Impact of Fluid Choice in Systemic Inflammatory Response Syndrome Patients on Hospital Cost Savings

BACKGROUND

There is growing evidence of the benefits of intravenous fluid therapy with balanced crystalloids over 0.9% 'normal' saline. This analysis evaluated the economic impact of increasing usage of a calcium-free balanced crystalloid solution (BAL) in patients with systemic inflammatory response syndrome (SIRS) on an annual hospital budget.

METHODS

An Excel^®-based economic model was developed to estimate costs associated with increased BAL usage (i.e., use in a greater proportion of patients), from the US hospital perspective, over a 5-year time horizon. Clinical inputs were based on the results of a retrospective Electronic Health Record (EHR) database analysis identifying significantly fewer complications among SIRS patients receiving predominantly BAL versus saline. Complication-associated costs, adjusted to 2015, were obtained from published reports. Scenario analyses examined cost impacts for hospitals of various sizes, with different BAL adoption levels and rates.

RESULTS

Base-case scenario analysis (300-bed hospital, 80% occupancy, current and year 5 BAL usage in 5 and 75% of SIRS patients, respectively, exponential year-over-year adoption) showed year 1 hospital savings of US$29,232 and cumulative 5-year savings of US$1.16M. Cumulative 5-year pharmacy savings were US$172,641. Scenario analyses demonstrated increasing cumulative 5-year savings with increasing hospital size, year 5 BAL usage in greater proportions of patients, and rapid/early BAL adoption.

CONCLUSIONS

Increased BAL usage represents an opportunity for hospitals and pharmacy departments to reduce complication-related costs associated with managing SIRS patients. The model suggests that savings could be expected across a range of scenarios, likely benefiting hospitals of various sizes and with different adoption capabilities.

Crystalloid fluid choice in the critically ill : Current knowledge and critical appraisal

Intravenous infusion of crystalloid solutions is one of the most frequently administered medications worldwide. Available crystalloid infusion solutions have a variety of compositions and have a major impact on body systems; however, administration of crystalloid fluids currently follows a "one fluid for all" approach than a patient-centered fluid prescription. Normal saline is associated with hyperchloremic metabolic acidosis, increased rates of acute kidney injury, increased hemodynamic instability and potentially mortality. Regarding balanced infusates, evidence remains less clear since most studies compared normal saline to buffered infusion solutes.; however, buffered solutes are not homogeneous. The term "buffered solutes" only refers to the concept of acid-buffering in infusion fluids but this does not necessarily imply that the solutes have similar physiological impacts. The currently available data indicate that balanced infusates might have some advantages; however, evidence still is inconclusive. Taking the available evidence together, there is no single fluid that is superior for all patients and settings, because all currently available infusates have distinct differences, advantages and disadvantages; therefore, it seems inevitable to abandon the "one fluid for all" strategy towards a more differentiated and patient-centered approach to fluid therapy in the critically ill.

0.9% NaCl (Normal Saline) - Perhaps not so normal after all?

Crystalloid infusion is widely employed in patient care for volume replacement and resuscitation. In the United States the crystalloid of choice is often normal saline. Surgeons and anesthesiologists have long preferred buffered solutions such as Ringer's Lactate and Plasma-Lyte A. Normal saline is the solution most widely employed in medical and pediatric care, as well as in hematology and transfusion medicine. However, there is growing concern that normal saline is more toxic than balanced, buffered crystalloids such as Plasma-Lyte and Lactated Ringer's. Normal saline is the only solution recommended for red cell washing, administration and salvage in the USA, but Plasma-Lyte A is also FDA approved for these purposes. Lactated Ringer's has been traditionally avoided in these applications due to concerns over clotting, but existing research suggests this is not likely a problem. In animal models and clinical studies in various settings, normal saline can cause metabolic acidosis, vascular and renal function changes, as well as abdominal pain in comparison with balanced crystalloids. The one extant randomized trial suggests that in very small volumes (2 l or less) normal saline is not more toxic than other crystalloids. Recent evidence suggests that normal saline causes substantially more in vitro hemolysis than Plasma-Lyte A and similar solutions during short term storage (24 hours) after washing or intraoperative salvage. There are now abundant data to raise concerns as to whether normal saline is the safest replacement solution in infusion therapy, red cell washing and salvage, apheresis and similar uses. In the USA, Plasma-Lyte A is also FDA approved for use with blood components and is likely a safer solution for these purposes. Its only disadvantage is a higher cost. Additional studies of the safety of normal saline for virtually all current clinical uses are needed. It seems likely that normal saline will eventually be abandoned in favor of safer, more physiologic crystalloid solutions in the coming years.

Acetate-buffered crystalloid infusate versus infusion of 0.9% saline and hemodynamic stability in patients undergoing renal transplantation : Prospective, randomized, controlled trial

Background

Infusion therapy is one of the most frequently prescribed medications in hospitalized patients. Currently used crystalloid solutes have a variable composition and may therefore influence acid-base status, intracellular and extracellular water content and plasma electrolyte compositions and have a major impact on organ function and outcome. The aim of our study was to investigate whether use of acetate-based balanced crystalloids leads to better hemodynamic stability compared to 0.9% saline.

Methods

We performed a sub-analysis of a prospective, randomized, controlled trial comparing effects of 0.9% saline or an acetate-buffered, balanced crystalloid during the perioperative period in patients with end-stage renal disease undergoing cadaveric renal transplantation. Need for catecholamine therapy and blood pressure were the primary measures.

Results

A total of 150 patients were included in the study of which 76 were randomized to 0.9% saline while 74 received an acetate-buffered balanced crystalloid. Noradrenaline for cardiocirculatory support during surgery was significantly more often administered in the normal saline group, given earlier and with a higher cumulative dose compared to patients receiving an acetate-buffered balanced crystalloid (30% versus 15%, p = 0.027; 68 ± 45 µg/kg versus 75 ± 60 µg/kg, p = 0.0055 and 0.000492 µg/kg body weight/min, ±0.002311 versus 0.000107 µg/kg/min, ±0.00039, p = 0.04, respectively). Mean minimum arterial blood pressure was significantly lower in patients randomized to 0.9% saline than in patients receiving the balanced infusion solution (57.2 [SD 8.7] versus 60.3 [SD 10.2] mm Hg, p = 0.024).

Conclusion

The use of an acetate-buffered, balanced infusion solution results in reduced need for use of catecholamines and cumulative catecholamine dose for hemodynamic support and in less occurrence of arterial hypotension in the perioperative period. Further research in the field is strongly encouraged.

Acetate-buffered crystalloid fluids: Current knowledge, a systematic review

INTRODUCTION

The concept of fluid resuscitation with balanced solutions containing acetate is relatively new. The knowledge about acetate mostly originates from nephrological research, as acetate was primarily used as a dialysis buffer where much higher doses of acetate are infused. The aim of this review is to give an overview of the advantages and disadvantages of an acetate-buffered crystalloid fluid when compared with other crystalloid infusates.

METHODS

We report trials with the primary object of comparing an acetate-buffered infusion solute to another crystalloid infusate. A systematic literature search of MEDLINE and the Cochrane Controlled Clinical trials register was conducted to identify suitable studies.

RESULTS

The search strategy used produced 1205 potential titles. After eliminating doubles, 312 titles and abstracts were screened, and 31 references were retrieved for full-text analysis. A total of 27 scientific studies were included in the study.

CONCLUSION

Acetate-buffered crystalloid solutes do have a favorable influence on microcirculation. To what extent the acetate-buffered crystalloids influence kidney function is controversially discussed and not yet clear. Metabolic alkalosis did not occur in a single study in humans after an acetate-buffered infusate; potassium levels stayed stable in all studies. Cardiac output and contractility seem to be positively influenced; nonetheless, data on maintenance of a target blood pressure remain inconclusive. Whether acetate-buffered crystalloid fluids lead to lower rates of acute kidney injury and increased survival when compared with normal saline is yet unclear and may depend on the amount of fluid administered.

Perioperative intravenous fluid prescribing: a multi-centre audit

Background

Excessive or inadequate intravenous fluid given in the perioperative period can affect outcomes. A number of guidelines exist but these can conflict with the entrenched practice, evidence base and prescriber knowledge. We conducted a multi-centre audit of intraoperative and postoperative intravenous fluid therapy to investigate fluid administration practice and frequency of postoperative electrolyte disturbances.

Methods

A retrospective audit was done in five hospitals of adult patients undergoing elective major abdominal, gastrointestinal tract or orthopaedic surgery. The type, volume and quantity of fluid and electrolytes administered during surgery and in 3 days postoperatively was calculated, and electrolyte disturbances were studied using clinical records.

Results

Data from four hundred thirty-one patients in five hospitals covering 1157 intravenous fluid days were collected. Balanced crystalloid solutions were almost universally used in the operating theatre and were also the most common fluid administered postoperatively, followed by hypotonic dextrose-saline solutions and 0.9 % sodium chloride. For three common uncomplicated elective operations, the volume of fluid administered intraoperatively demonstrated considerable variability. Over half of the patients received no postoperative fluid on day 1, and even more were commenced on free oral fluids immediately postoperatively or on day 1. Postoperative quantities of sodium exceeded the recommended amounts for maintenance in half of the patients who continued to receive intravenous fluids. Potassium administration in those receiving intravenous fluids was almost universally inadequate. Hypokalaemia and hyponatraemia were the common findings.

Conclusions

We documented the current clinical practice and confirmed that early free oral fluids and cessation of any intravenous fluids is common postoperatively in keeping with the aims of enhanced recovery after surgery programmes. Excessive sodium and water and inadequate potassium in those given intravenous fluids postoperatively is common and needs to be investigated. The variation in intraoperative fluid volume administration for three common procedures is considerable and in keeping with other international studies. Future trials of fluid therapy should include the intraoperative and postoperative phases.

The great fluid debate: saline or so-called "balanced" salt solutions?

Background

Intravenous fluids are commonly prescribed in childhood. 0.9 % saline is the most-used fluid in pediatrics as resuscitation or maintenance solution. Experimental studies and observations in adults suggest that 0.9 % saline is a poor candidate for fluid resuscitation. Although anesthesiologists, intensive care specialists, perioperative physicians and nephrologists have been the most active in this debate, this issue deserves some physiopathological considerations also among pediatricians.

Results

As compared with so-called “balanced” salt crystalloids such as lactated Ringer, administration of large volumes of 0.9 % saline has been associated with following deleterious effects: tendency to hyperchloremic metabolic acidosis (called dilution acidosis); acute kidney injury with reduced urine output and salt retention; damaged vascular permeability and stiffness, increase in proinflammatory mediators; detrimental effect on coagulation with tendency to blood loss; detrimental gastrointestinal perfusion and function; possible uneasiness at the bedside resulting in unnecessary administration of more fluids. Nevertheless, there is no firm evidence that these adverse effects are clinically relevant.

Conclusions

Intravenous fluid therapy is a medicine like insulin, chemotherapy or antibiotics. Prescribing fluids should fit the child’s history and condition, consider the right dose at the right rate as well as the electrolyte levels and other laboratory variables. It is unlikely that a single type of fluid will be suitable for all pediatric patients. “Balanced” salt crystalloids, although more expensive, should be preferred for volume resuscitation, maintenance and perioperatively. Lactated Ringer appears unsuitable for patients at risk for brain edema and for those with overt or latent chloride-deficiency. Finally, in pediatrics there is a need for new fluids to be developed on the basis of a better understanding of the physiology and to be tested in well-designed trials.

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.

Effects of fluid resuscitation with 0.9% saline versus a balanced electrolyte solution on acute kidney injury in a rat model of sepsis*

OBJECTIVE

To compare the acute effects of 0.9% saline versus a balanced electrolyte solution on acute kidney injury in a rat model of sepsis.

DESIGN

Controlled laboratory experiment.

SETTING

University laboratory.

SUBJECTS

Sixty adult, male Sprague-Dawley rats.

INTERVENTIONS

We induced sepsis by cecal ligation and puncture and randomized animals to receive fluid resuscitation with either 0.9% saline or Plasma-Lyte solution for 4 hours after 18 hours of cecal ligation and puncture (10 mL/kg in the first hour and 5 mL/kg in the next 3 hr). Blood and urine specimens were obtained from baseline, 18 hours after cecal ligation and puncture, immediately after 4 hours fluid resuscitation, and 24 hours later. We measured blood gas, plasma electrolytes, creatinine, interleukin-6, cystatin C, and neutrophil gelatinase-associated lipocalin concentrations. We also analyzed urine for cystatin C and neutrophil gelatinase-associated lipocalin. We used Risk, Injury, Failure, Loss and End-stage criteria for creatinine to assess severity of acute kidney injury. We observed all animals for survival up to 1 day after resuscitation. Surviving animals were killed for kidney histology. Finally, we carried out an identical study in 12 healthy animals.

MEASUREMENTS AND MAIN RESULTS

Compared with Plasma-Lyte, 0.9% saline resuscitation resulted in significantly greater blood chloride concentrations (p < 0.05) and significantly decreased pH and base excess. Acute kidney injury severity measured by RIFLE criteria was increased with 0.9% saline compared with Plasma-Lyte resuscitation (p < 0.05), and these results were consistent with kidney histology and biomarkers of acute kidney injury. Twenty-four-hour survival favored Plasma-Lyte resuscitation (76.6% vs 53.3%; p = 0.03). Finally, in healthy animals, we found no differences between fluids and no evidence of acute kidney injury.

CONCLUSION

Volume resuscitation with Plasma-Lyte resulted in less acidosis and less kidney injury and improved short-term survival when compared with 0.9% saline in this experimental animal model of sepsis.

National survey of fluid therapy in acute pancreatitis: current practice lacks a sound evidence base

BACKGROUND

Fluid therapy (FT) is a critical intervention in managing acute pancreatitis (AP). There is a paucity of evidence to guide FT and virtually no data on current prescribing practice. This survey aims to characterize current practice and opinion with regard to FT in AP throughout New Zealand.

METHODS

Information was collected on fluid selection, administration, and goal-directed FT. The survey was distributed online and in print to all doctors employed in General Surgery Departments in New Zealand on 1 May 2012. Monthly email reminders were sent for 6 months.

RESULTS

The overall response rate was 47 % (n = 190/408). Crystalloids were the preferred initial fluid for all categories of severity; however, colloid use increased with severity (p < 0.001). Fluid volume also increased with severity (p = 0.001), with 74 % of respondents prescribing >4 L for AP with organ failure (OF). Clinicians treating 26-50 patients per year with AP were less likely to prescribe colloid for AP with OF (8 vs 43 %) (p = 0.001). Rate of fluid administration in AP with OF varied according to physicians' seniority (p = 0.004); consultants prescribed >4 L more than other groups (83 vs 68 %). Only 17 % of respondents reported the use of guidelines.

CONCLUSIONS

This survey reveals significant variation in prescription of FT for AP, and aggressive FT is commonly prescribed for AP with OF. There is little adherence to published guidelines or best available evidence.

The ideal crystalloid - what is 'balanced'?

PURPOSE OF REVIEW

This review explores the contemporary definition of the term 'balanced crystalloid' and outlines optimal design features and their underlying rationale.

RECENT FINDINGS

Crystalloid interstitial expansion is unavoidable, but also occurs with colloids when there is endothelial glycocalyx dysfunction. Reduced chloride exposure may lessen kidney dysfunction and injury with a possible mortality benefit. Exact balance from an acid-base perspective is achieved with a crystalloid strong ion difference of 24 mEq/l. This can be done simply by replacing 24 mEq/l of chloride in 0.9% sodium chloride with bicarbonate or organic anion bicarbonate substitutes. Potassium, calcium and magnesium additives are probably unnecessary. Large volumes of mildly hypotonic crystalloids such as lactated Ringer's solution reduce extracellular tonicity in volunteers and increase intracranial pressure in nonbrain-injured experimental animals. A total cation concentration of 154 mmol/l with accompanying anions provides isotonicity. Of the commercial crystalloids, Ringer's acetate solution is close to balanced from both acid-base and tonicity perspectives, and there is little current evidence of acetate toxicity in the context of volume loading, in contrast to renal replacement.

SUMMARY

The case for balanced crystalloids is growing but unproven. A large randomized controlled trial of balanced crystalloids versus 0.9% sodium chloride is the next step.

Undergraduate medical textbooks do not provide adequate information on intravenous fluid therapy: a systematic survey and suggestions for improvement

BACKGROUND

Inappropriate prescribing of intravenous (IV) fluid, particularly 0.9% sodium chloride, causes post-operative complications. Fluid prescription is often left to junior medical staff and is frequently poorly managed. One reason for poor intravenous fluid prescribing practices could be inadequate coverage of this topic in the textbooks that are used.

METHODS

We formulated a comprehensive set of topics, related to important common clinical situations involving IV fluid therapy, (routine fluid replacement, fluid loss, fluids overload) to assess the adequacy of textbooks in common use. We assessed 29 medical textbooks widely available to students in the UK, scoring the presence of information provided by each book on each of the topics. The scores indicated how fully the topics were considered: not at all, partly, and adequately. No attempt was made to judge the quality of the information, because there is no consensus on these topics.

RESULTS

The maximum score that a book could achieve was 52. Three of the topics we chose were not considered by any of the books. Discounting these topics as "too esoteric", the maximum possible score became 46. One textbook gained a score of 45, but the general score was poor (median 11, quartiles 4, 21). In particular, coverage of routine postoperative management was inadequate.

CONCLUSIONS

Textbooks for undergraduates cover the topic of intravenous therapy badly, which may partly explain the poor knowledge and performance of junior doctors in this important field. Systematic revision of current textbooks might improve knowledge and practice by junior doctors. Careful definition of the remit and content of textbooks should be applied more widely to ensure quality and "fitness for purpose", and avoid omission of vital knowledge.

Perioperative intravascular volume replacement and kidney insufficiency

Perioperative acute kidney injury (AKI) occurrence is probably increased in recent years due to the increased level of complexity of surgical procedures and severity of illness of surgical patients. Perioperative AKI has a multifactorial aetiology (preoperative co-morbidities such as diabetes, heart failure and chronic kidney disease, emergent surgery, exposure to nephrotoxic drugs, haemodynamic instability, hypothermia, inflammatory response to surgery, hospital-acquired infections and abdominal compartment syndrome). However, fluid choice for perioperative volume replacement might have a major role in perioperative AKI, as administration of crystalloid solutions, colloids or haemoderivates has the potential for kidney injury. This review focusses on the issue of fluid replacement quality and quantity and their association with renal dysfunction.

Intraoperative crystalloid overload leads to substantial inflammatory infiltration of intestinal anastomoses-a histomorphological analysis

BACKGROUND

It has been shown that crystalloid fluid-overload promotes anastomotic instability. As physiologic anastomotic healing requires the sequential infiltration of different cells, we hypothesized this to be altered by liberal fluid regimes and performed a histomorphological analysis.

METHODS

36 Wistar rats were randomized into 4 groups (n=8-10 rats/group) and treated with either liberal (+) or restrictive (-) perioperative crystalline (Jonosteril = Cry) or colloidal fluid (Voluven = Col). Anastomotic samples were obtained on postoperative day 4, routinely stained and histophathologically reviewed. Anastomotic healing was assessed using a semiquantitative score, assessing inflammatory cells, anastomotic repair and collagenase activity.

RESULTS

Overall, the crystalloid overload group (Cry (+)) showed the worst healing score (P < 0.01). A substantial increase of lymphocytes and macrophages was found in this group compared to the other three (P < 0.01). Both groups that received colloidal fluid (Col (+) and Col (-)) as well as the group that received restricted crystalloid fluid resuscitation (Cry (-)) had better intestinal healing. Collagenase activity was significantly higher in the Cry (+) group.

CONCLUSION

Intraoperative infusion of high-volume crystalloid fluid leads to a pathological anastomotic inflammatory response with a marked infiltration of leukocytes and macrophages resulting in accelerated collagenolysis.