Advances in pediatric dehydration therapy

Critical Information from High Fidelity Arterial and Venous Pressure Waveforms During Anesthesia and Hemorrhage

PURPOSE

Peripheral venous pressure (PVP) waveform analysis is a novel, minimally invasive, and inexpensive method of measuring intravascular volume changes. A porcine cohort was studied to determine how venous and arterial pressure waveforms change due to inhaled and infused anesthetics and acute hemorrhage.

METHODS

Venous and arterial pressure waveforms were continuously collected, while each pig was under general anesthesia, by inserting Millar catheters into a neighboring peripheral artery and vein. The anesthetic was varied from inhaled to infused, then the pig underwent a controlled hemorrhage. Pearson correlation coefficients between the power of the venous and arterial pressure waveforms at each pig's heart rate frequency were calculated for each variation in the anesthetic, as well as before and after hemorrhage. An analysis of variance (ANOVA) test was computed to determine the significance in changes of the venous pressure waveform means caused by each variation.

RESULTS

The Pearson correlation coefficients between venous and arterial waveforms decreased as anesthetic dosage increased. In an opposing fashion, the correlation coefficients increased as hemorrhage occurred.

CONCLUSION

Anesthetics and hemorrhage alter venous pressure waveforms in distinctly different ways, making it critical for researchers and clinicians to consider these confounding variables when utilizing pressure waveforms. Further work needs to be done to determine how best to integrate PVP waveforms into clinical decision-making.

Recommendation document on rapid intravenous rehydration in acute gastroenteritis

INTRODUCTION

The efficacy and safety of the Rapid Intravenous Rehydration (RIR) guidelines in children affected by dehydration secondary to acute gastroenteritis is supported by current scientific evidence, but there is also great variability in its use in clinical practice.

OBJECTIVE

To prepare a document with evidence-based recommendations about RIR in paediatric population.

METHODS

The project was developed based on GRADE methodology, according to the following work schedule: Working Group training; creation of a catalogue of questions about research and definition of "relevant outcomes"; score and selection criteria for each item; bibliographic review; scientific evidence evaluation and synthesis (GRADE); review, discussion and creation of recommendations. 10 clinical questions and 15 relevant outcomes were created (7 about efficacy and 8 about security).

RESULTS

16 recommendations were set up, from which we can highlight as the main ones: 1) RIR is safe for children affected by mild-moderate dehydration secondary to acute gastroenteritis, unless expressly contraindicated or acute severe comorbidity (strong recommendation, moderate evidence). 2) Its use is recommended in this situation when oral rehydration has failed or due to contraindication (strong, high). 3) Isotonic fluids are recommended (strong, high), suggesting saline fluid as the first option (light, low), supplemented by glucose (2.5%) in those patients showing normoglycemia and ketosis (strong, moderate). 4) A rhythm of 20cc/kg/h is recommended (strong, high) during 1-4 h (strong, moderate).

CONCLUSIONS

This document establishes consensus recommendations, based on the available scientific evidence, which could contribute to the standardisation of the use of RIR in our setting.

[Recommendation document on rapid intravenous rehydration in acute gastroenteritis]

INTRODUCTION

The efficacy and safety of the rapid intravenous rehydration (RIR) guidelines in children affected by dehydration secondary to acute gastroenteritis is supported by current scientific evidence, but there is also great variability in its use in clinical practice.

OBJECTIVE

To prepare a document with evidence-based recommendations about RIR in paediatric population.

METHODS

The project was developed based on GRADE methodology, according to the following work schedule: Working Group training; creation of a catalogue of questions about research and definition of «relevant outcomes»; score and selection criteria for each item; bibliographic review; scientific evidence evaluation and synthesis (GRADE); review, discussion and creation of recommendations. 10 clinical questions and 15 relevant outcomes were created (7 about efficacy and 8 about security).

RESULTS

Sixteen recommendations were set up, from which we can highlight as the main ones: (1) RIR is safe for children affected by mild-moderate dehydration secondary to acute gastroenteritis, unless expressly contraindicated or acute severe comorbidity (strong recommendation and moderate evidence). (2) Its use is recommended in this situation when oral rehydration has failed or due to contraindication (strong and high). (3) Isotonic fluids are recommended (strong and high), suggesting saline fluid as the first option (light and low), supplemented by glucose (2.5%) in those patients showing normoglycemia and ketosis (strong and moderate). (4) A rhythm of 20 cc/kg/h is recommended (strong and high) during 1-4 h (strong and moderate).

CONCLUSIONS

This document establishes consensus recommendations, based on the available scientific evidence, which could contribute to the standardisation of the use of RIR in our setting.

Anesthetics affect peripheral venous pressure waveforms and the cross-talk with arterial pressure

Analysis of peripheral venous pressure (PVP) waveforms is a novel method of monitoring intravascular volume. Two pediatric cohorts were studied to test the effect of anesthetic agents on the PVP waveform and cross-talk between peripheral veins and arteries: (1) dehydration setting in a pyloromyotomy using the infused anesthetic propofol and (2) hemorrhage setting during elective surgery for craniosynostosis with the inhaled anesthetic isoflurane. PVP waveforms were collected from 39 patients that received propofol and 9 that received isoflurane. A multiple analysis of variance test determined if anesthetics influence the PVP waveform. A prediction system was built using k-nearest neighbor (k-NN) to distinguish between: (1) PVP waveforms with and without propofol and (2) different minimum alveolar concentration (MAC) groups of isoflurane. 52 porcine, 5 propofol, and 7 isoflurane subjects were used to determine the cross-talk between veins and arteries at the heart and respiratory rate frequency during: (a) during and after bleeding with constant anesthesia, (b) before and after propofol, and (c) at each MAC value. PVP waveforms are influenced by anesthetics, determined by MANOVA: p value < 0.01, η² = 0.478 for hypovolemic, and η² = 0.388 for euvolemic conditions. The k-NN prediction models had 82% and 77% accuracy for detecting propofol and MAC, respectively. The cross-talk relationship at each stage was: (a) ρ = 0.95, (b) ρ = 0.96, and (c) could not be evaluated using this cohort. Future research should consider anesthetic agents when analyzing PVP waveforms developing future clinical monitoring technology that uses PVP.

Venous Physiology Predicts Dehydration in the Pediatric Population

BACKGROUND

No standard dehydration monitor exists for children. This study attempts to determine the utility of Fast Fourier Transform (FFT) of a peripheral venous pressure (PVP) waveform to predict dehydration.

MATERIALS AND METHODS

PVP waveforms were collected from 18 patients. Groups were defined as resuscitated (serum chloride ≥ 100 mmol/L) and hypovolemic (serum chloride < 100 mmol/L). Data were collected on emergency department admission and after a 20 cc/kg fluid bolus. The MATLAB (MathWorks) software analyzed nonoverlapping 10-s window signals; 2.4 Hz (144 bps) was the most demonstrative frequency to compare the PVP signal power (mmHg).

RESULTS

Admission FFTs were compared between 10 (56%) resuscitated and 8 (44%) hypovolemic patients. The PVP signal power was higher in resuscitated patients (median 0.174 mmHg, IQR: 0.079-0.374 mmHg) than in hypovolemic patients (median 0.026 mmHg, IQR: 0.001-0.057 mmHg), (P < 0.001). Fourteen patients received a bolus regardless of laboratory values: 6 (43%) resuscitated and 8 (57%) hypovolemic. In resuscitated patients, the signal power did not change significantly after the fluid bolus (median 0.142 mmHg, IQR: 0.032-0.383 mmHg) (P = 0.019), whereas significantly increased signal power (median 0.0474 mmHg, IQR: 0.019-0.110 mmHg) was observed in the hypovolemic patients after a fluid bolus at 2.4 Hz (P < 0.001). The algorithm predicted dehydration for window-level analysis (sensitivity 97.95%, specificity 93.07%). The algorithm predicted dehydration for patient-level analysis (sensitivity 100%, specificity 100%).

CONCLUSIONS

FFT of PVP waveforms can predict dehydration in hypertrophic pyloric stenosis. Further work is needed to determine the utility of PVP analysis to guide fluid resuscitation status in other pediatric populations.

Clinical Impact of Rapid Intravenous Rehydration With Dextrose Serum in Children With Acute Gastroenteritis

OBJECTIVES

We designed a study to compare rapid intravenous rehydration based on 0.9% normal saline (NS) or on NS + glucose 2.5% serum (SGS 2.5%) in patients with dehydration secondary to acute gastroenteritis. Our hypothesis is that the addition of glucose 2.5% serum (SGS 2.5%) to 0.9% saline solution could reduce the proportion of hospital admissions and return emergency visits in these patients. The secondary objective was to identify differences in the evolution of blood glucose and ketonemia between the groups.

METHODS

We designed a prospective randomized open-label clinical trial that was conducted in 2 tertiary hospitals over 9 months. Patients were randomized to receive SGS 2.5% or NS. Baseline clinical, analytical, and disease-related data were collected. Data were analyzed using SPSS.

RESULTS

The frequency of hospitalization in the SGS 2.5% group was 30.3% (n = 23) compared with 34.8% (n = 24) in the NS group, although the difference was not statistically significant (P = 0.59). The frequency of return visits to the emergency department was 17.8% (n = 8) in the NS group and 5.6% (n = 3) in the SGS 2.5% group (P = 0.091). Changes in glucose and ketone levels were more favorable in the SGS 2.5% group.

CONCLUSIONS

Our results enabled us to conclude that there were no significant differences in hospital admission or return visits to the emergency department between children with dehydration secondary to acute gastroenteritis.

Optimizing peripheral venous pressure waveforms in an awake pediatric patient by decreasing signal interference

The purpose of this technological notes paper is to describe our institution's experience collecting peripheral venous pressure (PVP) waveforms using a standard peripheral intravenous catheter in an awake pediatric patient. PVP waveforms were collected from patients with hypertrophic pyloric stenosis. PVP measurements were obtained prospectively at two time points during the hospitalization: admission to emergency department and after bolus in emergency department. Data was collected from thirty-two patients. Interference in the PVP waveforms data collection was associated with the following: patient or device motion, system set-up error, type of IV catheter, and peripheral intravenous catheter location. PVP waveforms can be collected in an awake pediatric patient and adjuncts to decrease signal interference can be used to optimize data collection.

Rapid Intravenous Rehydration Therapy in Children With Acute Gastroenteritis: A Systematic Review

BACKGROUND

Rapid intravenous (IV) rehydration is commonly used for the management of pediatric gastroenteritis in the emergency department. The current practice shows wide variation in the volume and rate of rapid IV hydration. The aim of this review was to assess the efficacy of rapid IV rehydration compared with standard method in children with gastroenteritis.

METHOD

MEDLINE (1946-2014), EMBASE (1974-2014), and CENTRAL via the Cochrane Library (Issue 8, 2014) were systematically searched to identify eligible studies. Inclusion criteria were randomized controlled trials of rapid IV rehydration in children with gastroenteritis.

RESULTS

A total of 1513 articles were retrieved, and our inclusion criteria were met by 3 studies, with a total of 464 participants. The percentage of children who were successfully rehydrated and tolerated oral fluids at 2 to 4 hours after starting IV fluid therapy ranged from 69% to 100% in both rapid IV rehydration and standard method. Time to discharge ranged from 2 to 6 hours (rapid rehydration) versus 2 to 5 hours (standard rehydration). Emergency department revisits ranged from 3% to 16% (rapid rehydration) versus 5% to 14% (standard). Summarized results suggested that rapid IV rehydration may be associated with longer time-to-discharge and higher readmission rates. The new evidence fails to demonstrate superiority of large-volume (60 mL/kg/h) over standard (20 mL/kg/h) IV rehydration.

CONCLUSIONS

Standard volume IV rehydration for 1 to 4 hours followed by oral hydration or maintenance IV fluids seems sufficient for most children with gastroenteritis requiring IV fluid administration. However, more evidence is needed to establish an optimal IV rehydration regimen.

Ondansetron and probiotics in the management of pediatric acute gastroenteritis in developed countries

PURPOSE OF REVIEW

Acute gastroenteritis (AGE) is a common and impactful disease, typically managed with supportive care. There is considerable interest in the role of adjunctive therapies, particularly ondansetron and probiotics in improving AGE outcomes. The purpose of this review is to present the latest evidence regarding the use of these agents in children with AGE in developed countries.

RECENT FINDINGS

Single-dose oral ondansetron is effective and safe in reducing hospital admissions and the use of intravenous rehydration in children with AGE in emergency-department-based trials. Ondansetron use has increased significantly; however, 'real-world' studies of effectiveness have documented less impressive clinical impacts. Similarly, probiotic consumption is growing rapidly. Although several strains appear to reduce the duration of diarrhea in hospitalized children, current data are insufficient to support the routine use of probiotics in outpatient pediatric AGE.

SUMMARY

Ondansetron and probiotics may improve patient outcomes in pediatric AGE. Appropriate strategies are needed to optimally integrate oral ondansetron into clinical practice to maximize its potential benefits. Although probiotics remain a promising option, there are challenges in generalizing the data available to patients presenting for outpatient care. Large randomized controlled trials are needed to definitively guide the clinical use of probiotics in outpatients in developed countries.