Isotonic Fluid Research Articles

Renal water conservation and the volume kinetics of fluid-induced diuresis: A retrospective analysis of two cohorts of elderly men.

Renal water conservation after an overnight fast mirrors the habitual intake of liquid. The hypothesis in the present study was that water conservation influences the diuretic response to infusion of two types of crystalloid fluid. Twenty‐three elderly male patients (mean age 72 years) underwent a total of 46 intravenous infusions of 1.0 or 1.5 L of either hypotonic non‐electrolyte fluid (glycine 1.5%) or isotonic electrolyte fluid (Ringer's acetate or 0.9% saline). Urine osmolality (used to indicate renal water conservation) and plasma creatinine were measured before the infusions started. A two‐volume model was fitted to repeated measurements of the blood haemoglobin concentration and the urinary excretion, using mixed‐effects modelling software. Urine osmolality was examined as a potential covariate to the fixed kinetic parameters. The results show that distribution and redistribution of infused fluid occurred twice as fast for the non‐electrolyte fluids as for the electrolyte‐containing fluids, while the urine flow showed less difference. For both types of fluid, high urine osmolality served as a statistically significant covariate to the rate constant describing urinary excretion. Simulations showed that a high pre‐infusion urine osmolality doubled the time required for the kidneys to excrete 50% of a 30‐minute infusion. High plasma creatinine independently prolonged the elimination of non‐electrolyte fluid. The use of 0.9% saline instead of Ringer's prolonged the excretion of electrolyte‐containing fluid. In conclusion, renal water conservation is a determinant of the diuretic response to crystalloid fluid, regardless of whether the fluid contains electrolytes, and it should be considered in fluid balance studies.

Clinical Effects of Balanced Crystalloids vs Saline in Adults With Diabetic Ketoacidosis

Saline (0.9% sodium chloride), the fluid most commonly used to treat diabetic ketoacidosis (DKA), can cause hyperchloremic metabolic acidosis. Balanced crystalloids, an alternative class of fluids for volume expansion, do not cause acidosis and, therefore, may lead to faster resolution of DKA than saline. To compare the clinical effects of balanced crystalloids with the clinical effects of saline for the acute treatment of adults with DKA. This study was a subgroup analysis of adults with DKA in 2 previously reported companion trials-Saline Against Lactated Ringer's or Plasma-Lyte in the Emergency Department (SALT-ED) and the Isotonic Solutions and Major Adverse Renal Events Trial (SMART). These trials, conducted between January 2016 and March 2017 in an academic medical center in the US, were pragmatic, multiple-crossover, cluster, randomized clinical trials comparing balanced crystalloids vs saline in emergency department (ED) and intensive care unit (ICU) patients. This study included adults who presented to the ED with DKA, defined as a clinical diagnosis of DKA, plasma glucose greater than 250 mg/dL, plasma bicarbonate less than or equal to 18 mmol/L, and anion gap greater than 10 mmol/L. Data analysis was performed from January to April 2020. Balanced crystalloids (clinician's choice of Ringer lactate solution or Plasma-Lyte A solution) vs saline for fluid administration in the ED and ICU according to the same cluster-randomized multiple-crossover schedule. The primary outcome was time between ED presentation and DKA resolution, as defined by American Diabetes Association criteria. The secondary outcome was time between initiation and discontinuation of continuous insulin infusion. Among 172 adults included in this secondary analysis of cluster trials, 94 were assigned to balanced crystalloids and 78 to saline. The median (interquartile range [IQR]) age was 29 (24-45) years, and 90 (52.3%) were women. The median (IQR) volume of isotonic fluid administered in the ED and ICU was 4478 (3000-6372) mL. Cumulative incidence analysis revealed shorter time to DKA resolution in the balanced crystalloids group (median time to resolution: 13.0 hours; IQR: 9.5-18.8 hours) than the saline group (median: 16.9 hours; IQR: 11.9-34.5 hours) (adjusted hazard ratio [aHR] = 1.68; 95% CI, 1.18-2.38; P = .004). Cumulative incidence analysis also revealed shorter time to insulin infusion discontinuation in the balanced crystalloids group (median: 9.8 hours; IQR: 5.1-17.0 hours) than the saline group (median: 13.4 hours; IQR: 11.0-17.9 hours) (aHR = 1.45; 95% CI, 1.03-2.03; P = .03). In this secondary analysis of 2 cluster randomized clinical trials, compared with saline, treatment with balanced crystalloids resulted in more rapid resolution of DKA, suggesting that balanced crystalloids may be preferred over saline for acute management of adults with DKA. ClinicalTrials.gov Identifiers: NCT02614040; NCT02444988.

Effect of Isotonic and Hypotonic Fluid Therapy on Serum Sodium: A Randomized Controlled Trial

There is little consensus about the type of maintenance fluid therapy and it’s the effect on serum sodium in adults. Thus, this study was conducted to assess the effect of maintenance fluid therapy on serum sodium of hospitalized patients in the intensive care unit. This randomized clinical trial was carried out on 64 patients aged 18-90 years hospitalized in the intensive care unit (ICU) of Imam Sadjad and Shahid Beheshti hospitals, Yasuj, Iran, in 2017. These patients were randomly allocated to take 2500-3000 milliliters of intravenous maintenance isotonic (0.9% saline) or hypotonic (0.45% saline) fluids daily. Blood and urine samples were taken to measure biochemical parameters before and 48 hours after the intervention. Data analyses were done by using SPSS 16 software via descriptive and analytic statistics. Twenty-eight patients in the 0.9% saline group (19 male and 9 female) and 32 patients in 0.45% saline (20 male and 12 female) completed the study. There was no significant difference between two groups in sodium (P=0.94), potassium (P=0.21), sugar (P=0.91), creatinine (P=0.21), Blood Urea Nitrogen (P=0.99), systolic (P=0.81) and diastolic (P=0.73) blood pressure, PH (P=0.27), bicarbonate (P=0.8), and urine specific gravity (P=0.73). Based on the results of this study, it was shown that the administration of maintenance hypotonic fluids has been appropriate for the patients and will not face them with the risk of hyponatremia.

Hyponatraemia despite isotonic maintenance fluid therapy: a time series intervention study

ObjectiveTo examine the prevalence of dysnatraemias among children admitted for paediatric surgery before and after a change from hypotonic to isotonic intravenous maintenance fluid therapy.DesignRetrospective consecutive time series intervention study.SettingPaediatric...

Risk of Electrolyte Disorders in Acutely Ill Children Receiving Commercially Available Plasmalike Isotonic Fluids

The use of isotonic fluid therapy is currently recommended in children, but there is limited evidence of optimal fluid therapy in acutely ill children. To evaluate the risk for electrolyte disorders, including hyponatremia, hypernatremia, and hypokalemia, and the risk of fluid retention in acutely ill children receiving commercially available plasmalike isotonic fluid therapy. This unblinded, randomized clinical pragmatic trial was conducted at the pediatric emergency department of Oulu University Hospital, Finland, from October 3, 2016, through April 15, 2019. Eligible study subjects (N = 614) were between 6 months and 12 years of age, required hospitalization due to an acute illness, and needed intravenous fluid therapy. Exclusion criteria included a plasma sodium concentration of less than 130 mmol/L or greater than 150 mmol/L on admission; a plasma potassium concentration of less than 3.0 mmol/L on admission; clinical need of fluid therapy with 10% glucose solution; a history of diabetes, diabetic ketoacidosis, or diabetes insipidus; a need for renal replacement therapy; severe liver disease; pediatric cancer requiring protocol-determined chemotherapy hydration; and inborn errors of metabolism. All outcomes and samples size were prespecified except those clearly marked as exploratory post hoc analyses. All analyses were intention to treat. Acutely ill children were randomized to receive commercially available plasmalike isotonic fluid therapy (140 mmol/L of sodium and 5 mmol/L potassium in 5% dextrose) or moderately hypotonic fluid therapy (80 mmol/L sodium and 20 mmol/L potassium in 5% dextrose). The primary outcome was the proportion of children with any clinically significant electrolyte disorder, defined as hypokalemia less than 3.5 mmol/L, hypernatremia greater than 148 mmol/L, or hyponatremia less than 132 mmol/L during hospitalization due to acute illness. The main secondary outcomes were the proportion of children with severe hypokalemia and weight change. There were 614 total study subjects (mean [SD] age, 4.0 [3.1] years; 315 children were boys [51%] and all 614 were Finnish speaking [100%]). Clinically significant electrolyte disorder was more common in children receiving plasmalike isotonic fluid therapy (61 of 308 patients [20%]) compared with those receiving moderately hypotonic fluid therapy (9 of 306 patients [2.9%]; 95% CI of the difference, 12%-22%; P < .001). The risk of developing electrolyte disorder was 6.7-fold greater in children receiving isotonic fluid therapy. Hypokalemia developed in 57 patients (19%) and hypernatremia developed in 4 patients (1.3%) receiving plasmalike isotonic fluid therapy. Weight change was greater in children receiving isotonic, plasmalike fluid therapy compared with those receiving mildly hypotonic fluids (mean weight gain, 279 vs 195 g; 95% CI, 16-154 g; P = .02). In this randomized clinical trial, commercially available plasmalike isotonic fluid therapy markedly increased the risk for clinically significant electrolyte disorders, mostly due to hypokalemia, in acutely ill children compared with previously widely used moderately hypotonic fluid therapy containing 20 mmol/L of potassium. ClinicalTrials.gov identifier: NCT02926989.

Risks of severe hyponatremia in children receiving hypotonic fluids

Intravenous fluids are frequently used in hospitalized children. Hypotonic fluids have been the standard of care in pediatrics for many years. This might be explained by the empiricism of early recommendations favoring fluids with dextrose, but an insufficient amount of sodium. The risk of hyponatremia (<135mmol/L) might be increased by the occurrence of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) in the course of common acute diseases (e.g., bronchiolitis, acute gastroenteritis, encephalitis, meningitis) in children. Severe hyponatremia (<130mmol/L) is often associated with neurologic complications leading to sequelae or even death. Over the last few years, hyponatremia induced by hypotonic fluids has been increasingly reported, and significant progress has been made in the understanding of cerebral edema and osmotic demyelination. Several randomized clinical trials have shown weak but significant evidence that isotonic fluids were superior to hypotonic solutions in preventing hyponatremia. However, clinical practices have not changed much in France, as suggested by the analysis of intravenous fluids ordered from the Assistance Publique–Hôpitaux de Paris (AP–HP) central pharmacy (PCH) in 2017. Therefore, it would be advisable that national guidelines be released under the French Health Authorities regarding the safe infusion of infants and children.

Brain microdialysis in neurobiology and neurochemistry

Microdialysis is a versatile and popular minimally invasive technique which enables sampling, collecting, and continuous measurement of small-molecular-weight substances in the extracellular fluid of virtually any tissue. Widely established in pharmacology and neuroscience, it permits evaluation of the metabolism in any organ including brain and allows early detection of the cell stress. Concentrations of the target analytes in the dialysate are determined by the type of the analysed tissue, paracrine interactions, and technical features such as membrane type and surface area or flow rate of isotonic fluid. Cerebral (or brain) microdialysis can be used in personalised pharmacotherapy and prognostication in patients with neurological disorders. Here we discuss recent advances in brain microdialysis and focus on critical parameters defining its efficiency.

Management of community-acquired pneumonia in children: South African oracic Society guidelines (part 3)

Background. Pneumococcal conjugate vaccine (PCV) administration and other advances have been associated with a shift in the aetiological spectrum of community-acquired pneumonia, necessitating reconsideration of empiric antibiotic treatment guidelines. Management strategies have also evolved in the last decade. Objectives. To produce revised guidelines for the treatment of pneumonia in South African (SA) children, including ambulatory, hospital and intensive care management. Methods. An expert subgroup, reviewing evidence on the management of childhood pneumonia, was convened as part of a broader group revising SA guidelines. Evidence was graded using the British Thoracic Society (BTS) grading system and recommendations were made. Results. Antibiotic treatment depends on the child’s age, possible aetiology, antimicrobial resistance patterns, previous treatment, as well as factors affecting host susceptibility, including HIV, and nutritional and vaccination status. All children with signs of severe pneumonia should receive antibiotics. Children 1 month of age, high-dose amoxicillin remains the preferred antibiotic. For severe pneumonia in this age group, hospitalisation and empiric treatment with amoxicillin-clavulanate orally is recommended; if oral therapy is not tolerated, intravenous therapy is recommended. Generally, 5 days of therapy is proposed, but longer duration may be needed in cases of severe or complicated disease. A macrolide antibiotic should be used if pertussis, mycoplasma or chlamydia pneumonia is suspected. Most hypoxic children can receive oxygen via nasal cannulae, but respiratory support should be individualised and extends to non-invasive and invasive ventilation in some cases. Children should be fed enterally; if this is not possible, administer intravenous isotonic fluids at <80% of maintenance, with monitoring of sodium levels. Empiric antibiotic treatment is the same in HIV-infected, HIV-exposed uninfected and HIV-uninfected children, although treatment for pneumocystis pneumonia and/or cytomegalovirus pneumonia should be considered in HIV-infected infants, especially in the absence of combination antiretroviral therapy. Conclusions. Updated guidelines optimise the management of childhood pneumonia in the context of changing epidemiology, improvements in HIV prevention and new evidence on management.

Use of a Hyperosmolar Saline Solution to Mitigate Proinflammatory and Degradative Responses of Articular Cartilage and Meniscus for Application to Arthroscopic Surgery

This study was designed to evaluate differences in proinflammatory and degradative mediator production and extracellular matrix degradation from osteoarthritic knee articular cartilage and meniscus explants treated with either hyperosmolar saline or isotonic saline. 6 mm-diameter full-thickness explants were created from articular cartilage and menisci recovered after patients underwent knee surgery. One explant half was treated for 3 hours with hyperosmolar saline (600 mOsm/L) and the corresponding half with isotonic saline (300 mOsm/L). Explants were subsequently cultured for 3 days in tissue culture media. On day 3, media were collected for biomarker analyses. Results were normalized to tissue wet weight and analyzed statistically. Articular cartilage was collected from 10 patients (5male, 5 female; mean age= 66.9 years) and menisci were collected from 8 patients (2 male, 6 female; mean age= 66 years). Articular cartilage media concentrations of monocyte chemoattractant protein-1 (P= .001) and interleukin (IL)-6 (P= .049) were significantly lower in explants treated with hyperosmolar saline. Meniscus media concentrations of prostaglandin E2 (P= .008), monocyte chemoattractant protein-1 (P= .011), IL-6 (P= .029), IL-8 (P= .012), matrix metalloproteinase-2 (P= .011), and glycosaminoglycan (P= .008) were significantly lower in explants treated with hyperosmolar saline. Treatment of cartilage and meniscus explants with hyperosmolar saline effectively mitigated key proinflammatory mediator production, as well as degradative mediator production and glycosaminoglycan loss from meniscus, with no detrimental effects noted compared to isotonic saline. These results suggest that hyperosmolar saline irrigation fluid may provide a safe alternative to standard isotonic saline irrigation fluid, and could mitigate untoward effects associated with inflammatory responses after standard-of-care knee arthroscopy.

Prospective Randomized Controlled Clinical Trial Comparing Hyperosmolar Saline to Standard Isotonic Irrigation Fluid for Arthroscopic Knee Surgery

Objectives:Knee arthroscopy using isotonic irrigation fluids is performed safely in millions of patients each year. However, arthroscopic procedures can disrupt the native biology of the joint when hyperosmolar synovial fluid (400 mOsm/L) is replaced by isotonic irrigation fluid (270-300 mOsm/L). Potential ramifications include cell apoptosis and necrosis, alterations in gene expression, protein synthesis and calcium signaling, and extracellular matrix compositional changes with resultant material property perturbations. Recent in vitro studies suggest higher osmolarity irrigation fluids potentiate a chondroprotective environment and a clinical study using hyperosmolar saline for shoulder arthroscopy reported potential clinical advantages. To date, there are no studies examining the use of a hyperosmolar irrigation solution in patients undergoing knee arthroscopy to the authors’ knowledge. Therefore, this prospective randomized double-blind controlled clinical trial was designed to assess safety and efficacy of a hyperosmolar irrigation solution in patients undergoing arthroscopic knee surgery.Methods:With institutional review board approval and informed consent, adult patients scheduled to undergo arthroscopic knee surgery (i.e., chondroplasty, diagnostic, meniscectomy, meniscus repair) were randomized to surgery with either isotonic Lactated Ringer’s (273mOsm/L) or hyperosmolar saline (593 mOsm/L) irrigation solution. The hyperosmolar solution was created by adding 120cc of 23.4% NS solution to a 3L bag of 0.9% NS (Figure). Primary outcomes included perioperative blood pressure, knee girth, pain, and narcotic pain medication consumption. Blood pressure and knee girth measurements were performed before and after surgery. Visual Analogue Scale (VAS) pain scores and narcotic pain medication consumption were logged on post-operative days (POD) 1-3. Data from each cohort were pooled and analyzed for statistical significance (P<0.05) using an unpaired t-Test.Results:(Table): Forty-four patients underwent arthroscopic knee surgery with isotonic (N=23) or hyperosmolar (N=21) irrigation fluid. There were 11 males and 12 females (mean age 44.0 years) in the isotonic cohort and 7 males and 14 females (mean age 40.4 years) in the hyperosmolar cohort. There were no significant differences with respect to surgical duration (pump time), however, significantly (p=0.04) more irrigation fluid was used to complete the procedures in the isotonic cohort compared to the hyperosmolar cohort. There were no significant differences with respect to change in knee girth or blood pressure. There were no significant differences in VAS pain scores or narcotic medication consumption.Conclusion:The results of this randomized clinical trial suggest that the hyperosmolar irrigation solution used is safe for patients undergoing arthroscopic knee surgery. Less irrigation fluid was required when using the hyperosmolar solution with no apparent detrimental effects on execution of the surgical procedure, postoperative pain, or narcotic use. Taken together with previous studies showing chondroprotective and potential clinical benefits in arthroscopic shoulder surgery, the use of hyperosmolar saline irrigation fluid can be considered for clinical use in patients undergoing knee arthroscopy.Figure 1.Table 1.Demographic and Outcome ResultsParameterIsotonic (n=23)Hyperosmolar (n=21)PAge (years)44.0+13.840.4+11.50.34Sex11M/12F7M/14F0.37Pre-Op Blood Pressure139/88123/78 Post-Op Blood Pressure136/83123/76 Change in Knee Girth (cm)1.20+1.11.6+1.20.23Surgical Time (min)51.2+34.340.3+15.00.18Irrigation Fluid Used (mL)7374+48224823+2719 0.04 Amount of IVF (mL)889+491846+3700.75VAS Pain (POD 1)4.8+2.04.9+2.00.90VAS Pain (POD 2)4.8+2.53.9+1.70.17VAS Pain (POD 3)3.8+1.73.8+1.90.90Narcotic Pills Consumed (POD 1)2.9_2.12.7+2.30.84Narcotic Pills Consumed (POD 2)2.5+2.52.6+3.20.84Narcotic Pills Consumed (POD 3)2.3+2.61.1+2.00.15

Impact of Intraoperative Fluid Management on Electrolyte and Acid-Base Variables During Posterior Spinal Fusion in Adolescents.

IntroductionVarious isotonic fluids may be used to maintain intravascular homeostasis during major surgical procedures. Variations in the electrolyte and buffer concentrations between these solutions may result in differential changes in electrolyte and acid-base status during fluid resuscitation. This study evaluates these changes during posterior spinal fusion in adolescents.MethodsPatients were randomized to receive lactated Ringers (LR), normal saline (NS) or Normosol-R® (NR) during posterior spinal fusion (N=19, 20, and 20, respectively). The specific fluid was used for maintenance fluids as well as fluid replacement of deficits, third space losses, and blood loss.ResultsPatients who received NS had a greater base deficit (NS: −2.0 ± 2.2 vs NR −0.6 ± 1.8, p=0.031 or LR: −0.2 ± 1.7, p=0.007) and were more likely to have a ≥2 point change in the base deficit (60% with NS compared to 30% with NR and 47% with LR). Patients receiving NS also had a lower pH (NS: 7.37 ± 0.03 vs NR: 7.39 ± 0.04, p=0.013) and a greater change in pH (NS: −0.03 ± 0.04 vs NR: 0.01 ± 0.06).ConclusionThe use of NS for intraoperative resuscitation during posterior spinal fusion in adolescents resulted in a greater base deficit and a lower pH than the use of LR or NR. Although these changes had limited clinical significance in our patient population, future studies are indicated to further investigate the potential clinical impact of these changes.

Effect of Intravenous Fluid on Perioperative Plasma Sodium Concentration in Paediatric Surgical Patients

Background: There have been various publications on the risk of developing iatrogenic hyponatraemia following intravenous fluid administration in the pediatric age group. The aim of this study was to determine the suitable maintenance fluid that sustains normal plasma sodium levels in children in the perioperative period by comparing 4.3% dextrose in 0.18% saline with Ringer’s lactate when either is administered as maintenance fluid. Method: This study was carried out at the paediatric surgery unit of the Obafemi Awolowo University Teaching Hospital, Ile Ife, Nigeria between 1st September 2014 and 31st October 2015. This study is a comparative prospective study. There were 25 children in each group. One group received 4.3% dextrose in 0.18% saline, while the other group received Ringer’s lactate as maintenance fluid in the perioperative period. Serial blood and urine samples were collected before, during and after the surgery up till the first 24 hours. These samples were analyzed for sodium and creatinine concentration. Fractional excretion of sodium was calculated. Results were analyzed using SPSS software version 22. Results: There was no statistical significant difference between the two groups (p0.49) in term of age. The proportion of patients that developed hyponatraemia in the group that received hypotonic fluid was 32% (8/25), while it was 8% (2/25) in the group that received isotonic fluid (p=0.034). The patients who received Ringer’s lactate as maintenance fluid also had a higher mean plasma sodium concentration during the study. Conclusion: Ringer’s lactate was found to be a better fluid in terms of preventing hyponatraemia in children who are five years and below during the perioperative period compared to 4.3% dextrose in 0.18% normal saline.

P1158DOES THE PERITONEUM SWELLS OR SHRINK DURING PERITONEAL DIALYSIS?

Abstract Background and Aims The width of the peritoneum (composed mainly of connective tissue and relatively free of vasculature) is increased in patients on peritoneal dialysis compared to healthy subjects. We investigated to what extent increased intraperitoneal (ip) hydrostatic and osmotic pressures following the infusion of dialysis fluid will change hydration status and width of the peritoneum. Method Using linear theory of poroelasticty, clinical data on transport parameters and experimental data on elastic characteristics of the interstitium, the relative change of the width of the poroelastic layer subject to the combined effect of external hydrostatic and effective osmotic pressures (that is, ideal osmotic pressure multiplied by reflection coefficient for osmotic agent) can be described as a function of effective pressure and elastic modulus of the layer: Lmod/L0 = 1/(1-deltaP*/lambda*), where L0 is initial thickness of the tissue, Lmod is modified thickness of the layer, deltaP* is change in effective combined pressure, and lambda* is the elastic modulus of the poroelastic material. The same formula describes also the change in fractional free fluid volume ratio, thetaF. The elastic modulus of the connective tissue was assumed to be 110 mmHg, as measured for the subcutaneous layer of the tip of mouse tail by Swartz et al (J Biomech, 1999), and reflection coefficient for glucose in the interstitium of 0.0035 as estimated by Stachowska-Pietka et al (NDT, 2019) from clinical data for patients on peritoneal dialysis. Results The ip hydrostatic pressure increases by 2-3 mmHg to 15 mmHg at rest depending on infused volume of dialysis fluid (and posture, body weight and location in abdominal cavity), and may increase to 100 mmHg during activities as coughing, whereas the osmotic pressure of glucose 3.86% dialysis fluid is around 400 mmHg above the osmotic pressure of plasma and interstitial fluid (in equilibrium with plasma). However, due to the low reflection coefficient of interstitium, the effective osmotic pressure of dialysis fluid minus the physiological value of interstitial osmotic pressure is only 1.4 mmHg, and is quickly decreasing with dwell time. Therefore, hydrostatic pressure is the dominant factor for interstitial hydration. Assuming ip pressure of 15 mmHg, the stretch of the peritoneum increases its equilibrium width (at 0 mmHg and isotonic interstitial fluid) by 15%. During physical activities peritoneum may transiently thicken even more. Conclusion The peritoneum becomes overhydrated after infusion of dialysis fluid, which increases interstitial hydrostatic pressure; the thickness and fractional free fluid volume of the peritoneum increase by 15% although transiently higher increases may occur following activities that increase intraperitoneal pressure. The mechanical changes in the peritoneum may contribute to the biological changes in cells present there, as fibroblasts and mesothelial cells. The swelling of the peritoneum is in agreement with the increase in the fractional free fluid volume of the intramuscular interstitium behind the peritoneum as reported by Zakaria et al (Am J Physiol Heart Circ Physiol, 1999).

LIFE-THREATENING HYPERNATREMIA IN A 22-YEAR-OLD MAN WITH CONCURRENT DIABETIC KETOACIDOSIS AND HYPEROSMOLAR HYPERGLYCEMIC STATE

In diabetic ketoacidosis (DKA), hyponatremia is commonly observed due to hyperglycemia-induced water shift and osmotic diuresis. Thus, hypernatremia is rare and indicative of severe free water loss. We describe here a case of DKA with life-threatening hypernatremia. A 22-year-old type 1 diabetic male was admitted after experiencing polyuria and polydipsia, followed by nausea, vomiting, and lethargy for 2 weeks. On admission, plasma glucose was 1230 mg/dL and plasma sodium was 158 mEq/L. The patient developed acute kidney injury, lactic acidosis, and ketosis. Despite fluid resuscitation, sodium level continued to rise to 180 mEq/L. Tachycardia persisted and shock liver developed. After free water-deficit calculation, the patient was given more boluses of isotonic fluid in addition to 0.45% NaCl. Tachycardia began to improve, and hypernatremia and hyperglycemia were safely reduced. This case demonstrated how tedious volume evaluation and resuscitation helped the patient fully recover despite extreme hypernatremia, lethargy, and multiorgan failure.

Parenteral Fluid Therapy in Children

Parenteral fluids are commonly administered in the hospital setting. For decades, clinicians have used a standardized approach for the prescription of maintenance IV fluids. Such an approach, however, has led to concerns regarding the development of hyponatremia using hypotonic fluids, especially in settings of heightened ADH release such as hypovolemia. Compared to balanced solutions for IV fluid administration, normal saline use has led to separate concerns regarding the development of hyperchloremic metabolic acidosis and acute kidney injury. A number of randomized controlled trials have shown lower rates of hyponatremia using isotonic fluids when compared to hypotonic fluids. Clinical practice guidelines from the United Kingdom and United States have both recommended isotonic IV fluids for the otherwise healthy child in need of maintenance fluid administration, while those with alterations in water or solute balance require more individualized approaches. Large studies in adults have shown lower rates of acute kidney injury with balanced solutions compared to normal saline although similar data in children is lacking. Retrospective pediatric data has not shown a consistent difference between these interventions. Isotonic fluids should be first line therapy for otherwise healthy children in need of maintenance IV fluids. Evidence for the standard use of balanced solutions in children remains more limited, until large randomized trials can be performed.

Maintenance Fluid Therapy with Saline, Dextrose-Supplemented Saline or Lactated Ringer in Childhood: Short-Term Metabolic Effects.

Maintenance with isotonic fluids is recommended in children with gastroenteritis and failure of oral rehydration therapy. However, little is known on the short-term effects of the commonly prescribed intravenous solutions on metabolic balance in children. The aim of this study is to report on our experience with normal saline, dextrose-supplemented saline and lactated Ringer solution. Methods: A retrospective analysis from the charts of all previously apparently healthy children with acute gastroenteritis, mild to moderate dehydration and failure of oral rehydration, evaluated between January 2016 and December 2019 at our institution, was performed. Subjects prescribed the above-mentioned maintenance intravenous fluids and with blood testing immediately before starting fluid therapy and 4–6 h later, were eligible. The changes in bicarbonate, ionized sodium, potassium, chloride, anion gap and glucose were investigated. Kruskal–Wallis test with the post-hoc Dunn’s comparison and the Fisher exact test were applied. Results: A total of 134 out of 732 children affected by acute gastroenteritis were included (56 patients were prescribed normal saline, 48 dextrose-supplemented normal saline and 30 lactated Ringer solution). The effect of the three solutions on sodium and potassium was similar. As compared to non-supplemented normal saline (+0.4 (−1.9 – +2.2) mmol/L), dextrose-supplemented normal saline (+1.5 (+0.1 – +4.2) mmol/L) and lactated Ringer (+2.6 (+0.4 – +4.1) mmol/L) solution had a positive effect on plasma bicarbonate. Finally, the influence of dextrose-supplemented saline on blood glucose was different (+1.1 (+0.3 – +2.2) mmol/L) compared to that observed in cases hydrated with non-supplemented saline (−0.4 (−1.2 – +0.3) mmol/L) or lactated Ringer solution (−0.4 (−1.2 – +0.1) mmol/L). Conclusions: This study points out that maintenance intravenous therapies using normal saline, dextrose-supplemented saline or lactated Ringer solution have different effects on metabolic balance. A personalized fluid therapy that takes into account the clinical and biochemical variables is advised.

SUN-292 Life-Threatening Hypernatremia in Partial Diabetes Insipidus with Adipsia Due to Cranial Radiation: Diagnostic and Therapeutic Challenges

Background: Anterior pituitary dysfunction is a known, time and dose dependent effect of cranial radiotherapy but central diabetes insipidus (CDI) has been rarely reported. We present a patient with partial CDI (PCDI) and adipsia, months after subtotal resection and radiation therapy for a large anterior cranial fossa meningioma. Clinical Case: A 53-year-old woman with history of subtotal resection of a 7 cm meningioma ~2 years ago and radiation therapy (54 Gy, completed 15 months ago), was admitted to the ICU with obtundation, tachycardia (120/min), hypotension (87/52 mmHg, on vasopressors in the first 24 hours), severe hypernatremia (serum Na 170 mmol/L), and acute kidney injury (creatinine 2.11 mg/dL; baseline 1.0 mg/dL). Plasma osmolality (pOSM) was 385 mOsm/kg and urine osmolality (uOSM) was 982 mOsm/kg. MRI brain 3 months ago showed frontal lobe encephalomalacia, residual meningioma at the planum sphenoidale (1.8x3.5x2.8 cm) with cavitary lesion compatible with post-radiation necrosis. After receiving 4 litres (L) isotonic fluids and 5 L hypotonic fluids in the first 38 hours, serum Na was 168 mmol/L, creatinine 1.35 mg/dl and uOSM 386 mOsm/kg. Urine output was 2.6 L on day-1 and 1.9 L during first 7 hours on day-2. After an IV dose of 2 mcg DDAVP, uOSM increased to 784 mOsm/kg, and Na decreased to 164 mmol/L, supporting CDI diagnosis. ACTH stimulation test was normal. Levothyroxine 50 mcg daily was started for central hypothyroidism. By day-6, her mental status returned to baseline (alert only to person). DDAVP dose adjustment was challenging due to frequent fluctuation in her serum Na (130s to 150s), adipsia and urinary incontinence. On day-44, she was discharged on subcutaneous (subQ) DDAVP 0.25 mcg every 36 hours, with a serum Na of 145 mmol/L. She was readmitted 3 days later with serum Na of 164 mmol/L, followed by another prolonged hospitalization complicated by acute kidney injury and popliteal DVT. On day-64, she was discharged to a nursing facility on DDAVP 0.25 mcg subQ twice daily. Clinical Lesson: Delayed PCDI with adipsia is an exceedingly rare but challenging complication of cranial radiation therapy. The initial uOSM (twice as high as pOSM) in our case caused a delay in diagnosis. This could reflect enhanced antidiuretic response to low circulating ADH levels, possibly due to lower rate of solute extraction in dehydration, upregulation of ADH receptors due to chronic hormone deficiency, and to a fall in glomerular filtration rate. Decrease in uOSM after hydration could be due to ADH exhaustion.

Effects of Standard and Sustained-release Buprenorphine on the Minimum Alveolar Concentration of Isoflurane in C57BL/6 Mice.

Both standard and sustained-release injectable formulations of buprenorphine (Bup and BupSR, respectively) are used as preemptive analgesics, potentially affecting gas anesthetic requirements. This study tested the effects of Bup and BupSR on isoflurane requirements and confirmed that buprenorphine could reduce isoflurane requirements during a laparotomy in mice. We hypothesized that both Bup and BupSR would significantly decrease the required minimum alveolar concentration (MAC) of isoflurane. C57BL/6 mice received either isotonic crystalloid fluid (control), Bup (0.1 mg/kg), or BupSR (1.2 mg/kg) subcutaneously 10 min prior to the induction of anesthesia. Each anesthetized mouse was tested at 2 isoflurane concentrations. A 300-g noxious stimulus was applied at each isoflurane concentration, alternating between hindfeet. In addition, a subset of mice underwent terminal laparotomy or 60 min of anesthesia after injection with Bup, BupSR, or saline to ensure an appropriate surgical plane of anesthesia. Mice were maintained at the lowest isoflurane concentration that resulted in 100% of mice at a surgical plane from the aforementioned MAC experiments (control, 2.0%; Bup and BupSR, 1.7%). Analysis showed that both Bup and BupSR significantly decreased isoflurane requirements by 25.5% and 14.4%, respectively. The isoflurane MAC for the control injection was 1.80% ± 0.09%; whereas Bup and BupSR decreased MAC to 1.34% ± 0.08% and 1.54% ± 0.09%, respectively. Sex was not a significantly different between the injection groups during MAC determination. All of the mice that underwent surgery achieved a surgical plane of anesthesia on the prescribed regimen and recovered normally after discontinuation of isoflurane. Lastly, heart and respiratory rates did not differ between mice that underwent surgery and those that were anesthetized only. Bup and BupSR are MAC-sparing in male and female C57BL/6 mice and can be used for effective multimodal anesthesia.

Severe bronchoconstriction as part of a suspected anaphylactic reaction in a dog following administration of gadobutrol

A four-year-and-three-month-old Jack Russell terrier presented for investigation of acute-onset paraplegia, with an MRI performed under general anaesthesia. Following administration of a gadobutrol contrast medium, apnoea, cyanosis, resistance to ventilation,...

Clinical Practice Guideline for the Treatment of Traumatic Shock Patients from the Korean Society of Traumatology

Purpose: Despite recent developments in the management of trauma patients in South Korea, a standardized system and guideline for trauma treatment are absent. Methods: Five guidelines were assessed using the Appraisal of Guidelines for Research and Evaluation II instrument. Results: Restrictive volume replacement must be used for patients experiencing shock from trauma until hemostasis is achieved (1B). The target systolic pressure for fluid resuscitation should be 80-90 mmHg in hypovolemic shock patients (1C). For patients with head trauma, the target pressure for fluid resuscitation should be 100-110 mmHg (2C). Isotonic crystalloid fluid is recommended for initially treating traumatic hypovolemic shock patients (1A). Hypothermia should be prevented in patients with severe trauma, and if hypothermia occurs, the body temperature should be increased without delay (1B). Acidemia must be corrected with an appropriate means of treatment for hypovolemic trauma patients (1B). When a large amount of transfusion is required for trauma patients in hypovolemic shock, a massive transfusion protocol (MTP) should be used (1B). The decision to implement MTP should be made based on hemodynamic status and initial responses to fluid resuscitation, not only the patient’s initial condition (1B). The ratio of plasma to red blood cell concentration should be at least 1:2 for trauma patients requiring massive transfusion (1B). When a trauma patient is in life-threatening hypovolemic shock, vasopressors can be administered in addition to fluids and blood products (1B). Early administration of tranexamic acid is recommended in trauma patients who are actively bleeding or at high risk of hemorrhage (1B). For hypovolemic patients with coagulopathy non-responsive to primary therapy, the use of fibrinogen concentrate, cryoprecipitate, or recombinant factor VIIa can be considered (2C). Conclusions: This research presents Korea''s first clinical practice guideline for patients with traumatic shock. This guideline will be revised with updated research every 5 years.