Fluid Management for Critically Ill Patients: A Review of the Current State of Fluid Therapy in the Intensive Care Unit

A Comprehensive Review of Chloride Management in Critically Ill Patients

Chloride, often overshadowed in electrolyte management, emerges as a crucial player in the physiological intricacies of critically ill patients. This comprehensive review explores the multifaceted aspects of chloride, ranging from its significance in cellular homeostasis to the consequences of dysregulation in critically ill patients. The pathophysiology of hyperchloremia and hypochloremia is dissected, highlighting their intricate impact on acid-base balance, renal function, and cardiovascular stability. Clinical assessment strategies, including laboratory measurements and integration with other electrolytes, lay the foundation for targeted interventions. Consequences of dysregulated chloride levels underscore the need for meticulous management, leading to an exploration of emerging therapies and interventions. Fluid resuscitation protocols, the choice between crystalloids and colloids, the role of balanced solutions, and individualized patient approaches comprise the core strategies in chloride management. Practical considerations, such as monitoring and surveillance, overcoming implementation challenges, and embracing a multidisciplinary approach, are pivotal in translating theoretical knowledge into effective clinical practice. As we envision the future, potential impacts on critical care guidelines prompt reflections on integrating novel therapies, individualized approaches, and continuous monitoring practices. In conclusion, this review synthesizes current knowledge, addresses practical considerations, and envisions future directions in chloride management for critically ill patients. By embracing a holistic understanding, clinicians can navigate the complexities of chloride balance, optimize patient outcomes, and contribute to the evolving landscape of critical care medicine.

Correlation coefficient between plethysmographic variability index and Systolic Pressure Variation as an indicator for fluid responsiveness in hypotensive patients in the ICU/OT

Background

Prediction of fluid responsiveness in hypotensive patients is a challenge. The correlation between a novel noninvasive dynamic indicator, Pleth Variability Index (PVI ®), and a gold-standard Systolic Pressure Variation (SPV) as a measure of fluid responsiveness was assessed in the Intensive Care Unit (ICU) or Operation Theatre (OT) in a tertiary care hospital.

Methods

A prospective experimental study was conducted over a span of one year on 100 mechanically ventilated patients with hypotension. Vital parameters along with SPV and PVI ® were recorded before and after a standard volume expansion protocol. A 10% SPV threshold was used to define fluid responders and nonresponders.

Results

Pearson's correlation graph at baseline showed positive correlation between PVI ® and SPV (r = 0.59, p-value = 0.001). Strength of correlation was comparatively less but still showed positive correlation at 15 (r = 0.39, p-value = 0.009) and 30 (r = 0.404, p-value = 0.004) minutes of fluid bolus. The Bland Altman analysis of baseline values of PVI ® and SPV showed good agreement with a mean bias of 9.05. Percentage change of PVI ® and SPV over 30 min showed a statistically significant positive correlation in the responder group (r = 0.53, p < 0.05). A threshold value of PVI ® more than 18% before volume expansion differentiated fluid responders and nonresponders with a sensitivity of 75% and specificity of 67%, with an area under Receiver Operating Characteristic (ROC) of 0.78.

Conclusion

A positive correlation exists between SPV and PVI ®, justifying the use of noninvasive PVI ® in a clinical setting of hypotension.

Evaluation of the Easy Albumin-Bilirubin Score as a Prognostic Tool for Mortality in Adult Trauma Patients in the Intensive Care Unit: A Retrospective Study

The easy albumin-bilirubin (EZ-ALBI) score is derived using the following equation: total bilirubin (mg/dL) - 9 × albumin (g/dL). This study aimed to determine whether the EZ-ALBI score predicted mortality risk in adult trauma patients in an intensive care unit (ICU). Data from a hospital's trauma database were retrospectively evaluated for 1083 adult trauma ICU patients (139 deaths and 944 survivors) between 1 January 2016 and 31 December 2021. Patients were classified based on the ideal EZ-ALBI cut-off of -26.5, which was determined via receiver operating characteristic curve analysis. The deceased patients' EZ-ALBI scores were higher than those of the surviving patients (-26.8 ± 6.5 vs. -30.3 ± 5.9, p = 0.001). Multivariate logistic analysis revealed that, in addition to age, the presence of end-stage renal disease, Glasgow Coma Scale scores, and injury severity scores, the EZ-ALBI score is an independent risk factor for mortality (odds ratio (OR), 1.10; 95% confidence interval (CI): 1.06-1.14; p = 0.001)). Compared with patients with EZ-ALBI scores < -26.5, those with scores ≥ -26.5 had a 2.1-fold higher adjusted mortality rate (adjusted OR, 2.14; 95% CI: 1.43-3.19, p = 0.001). In conclusion, the EZ-ALBI score is a substantial and independent predictor of mortality and can be screened to stratify mortality risk in adult trauma ICU patients.

Investigating influences of intravenous fluids on HUVEC and U937 monocyte cell lines using the magnetic levitation method

Intravenous fluids are being widely used in patients of all ages for preventing or treating dehydration in the intensive care units, surgeries in the operation rooms, or administering chemotherapeutic drugs at hospitals. Dextrose, Ringer, and NaCl solutions are widely received as intravenous fluids by hospitalized patients. Despite their widespread administration for over 100 years, studies on their influences on different cell types have been very limited. Increasing evidence suggests that treatment outcomes might be altered by the choice of the administered intravenous fluids. In this study, we investigated the influences of intravenous fluids on human endothelial (HUVEC) and monocyte (U937) cell lines using the magnetic levitation technique. Our magnetic levitation platform provides label-free manipulation of single cells without altering their phenotypic or genetic properties. It allows for monitoring and quantifying behavior of single cells by measuring their levitation heights, deformation indices, and areas. Our results indicate that HUVEC and U937 cell lines respond differently to different intravenous fluids. Dextrose solution decreased the viability of both cell lines while increasing the heterogeneity of areas, deformation, and levitation heights of HUVEC cells. We strongly believe that improved outcomes can be achieved when the influences of intravenous fluids on different cell types are revealed using robust, label-free, and efficient methods.

Oral Water Has Cardiovascular Effects Up to 60 min in Shock Patients

Aim: Little is known about the cardiovascular effects of oral water intake in shock patients. This study was designed to assess the effect of oral water on stroke volume and blood pressure during a 1-h time period. Method and Results: This open-label, randomized clinical trial included patients admitted to intensive care with acute circulatory failure. Three ICU units at the anesthesia and critical care department of the Dijon Bourgogne University Hospital. Patients were randomized 1:1 to an intervention or standard care group. The intervention group received 500 ml of oral water while the standard care group received intravenous administration of 500 ml of physiological saline solution. Baseline SV did not differ between the two groups (36 ml [28;51] vs. 38 ml [30;51], p = 0.952). The number of patients who were fluid responders did not differ between the two groups [n = 19 (76%) vs. n = 18 (72%), p = 1]. The median change in stroke volume during the three time points did not differ between the two groups (p < 0.05). In the intervention group, blood pressure increased up to 60 min. In the control group, blood pressure quickly increased at the end of fluid expansion, then returned close to baseline value at 60 min. Conclusion: Shock patients who were administered oral water experienced improvements in blood pressure and blood flow up to 60 min when compared with patients who received intravenous saline solution. Further studies are warranted to confirm these effects. Clinical Trial Registration: www.clinicaltrials.gov, identifier: NCT03951519.

Variation in Fluid and Vasopressor Use in Shock With and Without Physiologic Assessment: A Multicenter Observational Study

OBJECTIVES

To characterize the association between the use of physiologic assessment (central venous pressure, pulmonary artery occlusion pressure, stroke volume variation, pulse pressure variation, passive leg raise test, and critical care ultrasound) with fluid and vasopressor administration 24 hours after shock onset and with in-hospital mortality.

DESIGN

Multicenter prospective cohort study between September 2017 and February 2018.

SETTINGS

Thirty-four hospitals in the United States and Jordan.

PATIENTS

Consecutive adult patients requiring admission to the ICU with systolic blood pressure less than or equal to 90 mm Hg, mean arterial blood pressure less than or equal to 65 mm Hg, or need for vasopressor.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

Of 1,639 patients enrolled, 39% had physiologic assessments. Use of physiologic assessment was not associated with cumulative fluid administered within 24 hours of shock onset, after accounting for baseline characteristics, etiology and location of shock, ICU types, Acute Physiology and Chronic Health Evaluation III, and hospital (beta coefficient, 0.04; 95% CI, -0.07 to 0.15). In multivariate analysis, the use of physiologic assessment was associated with a higher likelihood of vasopressor use (adjusted odds ratio, 1.98; 95% CI, 1.45-2.71) and higher 24-hour cumulative vasopressor dosing as norepinephrine equivalent (beta coefficient, 0.37; 95% CI, 0.19-0.55). The use of vasopressor was associated with increased odds of in-hospital mortality (adjusted odds ratio, 1.88; 95% CI, 1.27-2.78). In-hospital mortality was not associated with the use of physiologic assessment (adjusted odds ratio, 0.86; 95% CI, 0.63-1.18).

CONCLUSIONS

The use of physiologic assessment in the 24 hours after shock onset is associated with increased use of vasopressor but not with fluid administration.

Intravenous Fluid Management in Critically Ill Adults: A Review

TOPIC

This article reviews the management of intravenous fluids and the evaluation of volume status in critically ill adults.

CLINICAL RELEVANCE

Intravenous fluid administration is one of the most common interventions in the intensive care unit. Critically ill patients have dynamic fluid requirements, making the management of fluid therapy challenging. New literature suggests that balanced salt solutions may be preferred in some patient populations.

PURPOSE OF PAPER

The bedside critical care nurse must understand the properties of various intravenous fluids and their corresponding impact on human physiology. The nurse's clinical and laboratory assessments of each patient help define the goals of fluid therapy, which will in turn be used to determine the optimal patient-specific selection and dose of fluid for administration. Nurses serve a vital role in monitoring the safety and efficacy of intravenous fluid therapy. Although this intervention can be lifesaving, inappropriate use of fluids has the potential to yield detrimental effects.

CONTENT COVERED

This article discusses fluid physiology and the goals of intravenous fluid therapy, compares the types of intravenous fluids (isotonic crystalloids, including 0.9% sodium chloride and balanced salt solutions; hypotonic and hypertonic crystalloids; and colloids) and their adverse effects and impact on hemodynamics, and describes the critical care nurse's essential role in selecting and monitoring intravenous fluid therapy.

The Bucharest ESTES consensus statement on peritonitis

INTRODUCTION

Peritonitis is still an important health problem associated with high morbidity and mortality. A multidisciplinary approach to the management of patients with peritonitis may be an important factor to reduce the risks for patients and improve efficiency, outcome, and the cost of care.

METHODS

Expert panel discussion on Peritonitis was held in Bucharest on May 2017, during the 17th ECTES Congress, involving surgeons, infectious disease specialists, radiologists and intensivists with the goal of defining recommendations for the optimal management of peritonitis.

CONCLUSION

This document is an updated presentation of management of peritonitis and represents the summary of the final recommendations approved by a panel of experts.

Time course of fluid responsiveness in sepsis: the fluid challenge revisiting (FCREV) study

BACKGROUND

Fluid challenge (FC) is one of the most common practices in Intensive Care Unit (ICU). The present study aimed to evaluate whether echocardiographic assessment of the response to FC at the end of the infusion or 20 min later could affect the results of the FC.

METHODS

This is a prospective, observational, multicenter study including all ICU patients in septic shock requiring a FC of 500 mL crystalloids over 10 min. Fluid responsiveness was defined as a > 15% increase in stroke volume (SV) assessed by velocity-time integral (VTI) measurements at baseline (T₀), at the end of FC (T₁₀), then 10 (T₂₀) and 20 min (T₃₀) after the end of FC.

RESULTS

From May 20, 2014, to January 7, 2016, a total of 143 patients were enrolled in 11 French ICUs (mean age 64 ± 14 years, median IGS II 53 [43-63], median SOFA score 10 [8-12]). Among the 76/143 (53%) patient responders to FC at T₁₀, 37 patients were transient responders (TR), i.e., became non-responders (NR) at T₃₀ (49%, 95%CI = [37-60]), and 39 (51%, 95%CI = [38-62]) patients were persistent responders (PR), i.e., remained responders at T₃₀. Among the 67 NR at T₁₀, 4 became responders at T30, (6%, 95%CI = [1.9-15.3]). In the subgroup analysis, no statistical difference in hemodynamic and echocardiographic parameters was found between groups.

CONCLUSIONS

This study shows that 51.3% of initial responders have a persistent response to fluid 30 min after the beginning of fluid infusion and only 41.3% have a transient response highlighting that fluid responsiveness is time dependent.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT02116413 . Registered on April 16, 2014.

Evaluation of ventilator on lung profile of piglets (Sus scrofa) in hypovolemic shock treated with hypervolemic crystalloid resuscitation

Aim:

This study was conducted to assess the effect of ventilators on the lung profile of piglets in the hypovolemic shock before and after the excessive resuscitation of the crystalloid fluid.

Materials and Methods:

Five male piglets were used in this study as the models of shock, and there are four phases of treatment: Stabilization, shock of bleeding, normovolemic resuscitation, and hypervolemic resuscitation. The application of mechanical ventilation to patients who suspected of having lung injury may worsen the patient’s conditions. The purpose of this study was to set the ventilator with the set of positive end-expiratory pressure (PEEP) of 5 cm H₂O, thefraction of inspired oxygen (FiO₂) of 0.5, and the inspiration: expiration (I: E) ratio of 1:2, which was applied from the stabilization phase. The shock induction was performed by removing the blood until the mean arterial pressure decreasing by 20% from the stabilization. The solution of NaCl 0.9% was used for the normovolemic and hypervolemic resuscitation. The parameter of observation consisted of extravascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI) on pulse contour cardiac output 2 and exhaled tidal volume (VTE), peak inspiratory pressure (PIP), and respiratory rate (RR) on ventilators.

Results:

EVLWI does not indicate pulmonary edema. A significant decrease in VTE without any significant alterations in EVLWI, PIP, and RR has indicated the shallow breathing in the shock condition. Therefore, the PVPI parameter cannot be used as a parameter for capillary permeability since its formulation does not reinforce the results of data in the shock condition. The set of the ventilator may prevent the increase of EVLWI, and the uses of ventilators do not worsen the patient’s conditions during the crystalloid resuscitation.

Conclusion:

The use of mechanical ventilator as the support does not worsen the hypovolemic condition and is safe to use as long as the lung profile is not indicated to have lung injury.

Alterations in regional kidney oxygenation during expansion of extracellular fluid volume in conscious healthy sheep

Expansion of extracellular fluid volume with crystalloid solutions is a common medical intervention, but its effects on renal cortical and medullary oxygenation are poorly understood. Therefore, we instrumented sheep under general anesthesia to enable continuous measurement of systemic and renal hemodynamics, global renal oxygen delivery and consumption, and intrarenal tissue perfusion and oxygen tension (Po₂) in conscious animals ( n = 7). The effects of three sequential intermittent infusions of 500 ml of compound sodium lactate solution, administered at hourly intervals, were determined. Volume expansion induced transient increases in mean arterial pressure (+7 ± 2%), central venous pressure (+50 ± 19%), and cardiac output (+15 ± 3%). There were sustained increases in renal medullary tissue Po₂ (+35 ± 10%) despite increases in global renal oxygen consumption (+66 ± 18%) and renal oxygen extraction (+64 ± 8%). Volume expansion did not significantly alter renal blood flow, renal oxygen delivery, or medullary perfusion. The sustained increase in medullary Po₂ was paralleled by increased bladder urine Po₂ (34 ± 4%). Cortical perfusion and Po₂ did not change significantly. Our findings indicate that extracellular fluid volume expansion can increase renal medullary oxygenation, providing a potential mechanistic basis for its use as prophylaxis against iatrogenic acute kidney injury. They also indicate that continuous measurement of bladder urine Po₂ could be used to monitor the effects of volume expansion on medullary oxygenation. However, the mechanisms mediating increased medullary oxygenation during volume expansion remain to be determined.

Fluid resuscitation in critically ill patients: a systematic review and network meta-analysis

Objective

The aim of this study was to compare the effectiveness of different fluids on critically ill patients who need fluid resuscitation through a systematic review and network meta-analysis (NMA).

Data sources

Electronic databases were searched up to March 2018 for randomized controlled trials comparing the effectiveness of different fluids in critically ill patients. The primary outcome was mortality, and the secondary outcomes were the incident of acute kidney injury (AKI) and risk of receiving renal replacement therapy (RRT). A Bayesian NMA was conducted, and the quality of evidence contributing to each network estimate was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group criteria.

Results

We deemed 49 trials eligible, including 40,910 participants. The quality of evidence was rated as moderate in most comparisons. There was no significant difference among resuscitation fluids in mortality. NMA at the 9-node level showed the most effective fluid was balanced crystalloid (BC) (80.79%, the ranking of resuscitation fluid based on cumulative probability plots and surface under the cumulative ranking curves [SUCRAs]). NMA at the 10-node level showed that the most effective fluid was Plasma-Lyte (77.52%). Results of sensitivity analyses in mortality did not reveal any significant changes in the findings for primary outcomes. High-molecular-weight hetastarch (H-HES) was associated with an increased incidence of AKI when compared with gelatin (odds ratio [OR], 0.43; 95% credibility interval [CrI], 0.19–0.94), low-molecular-weight hetastarch (L-HES; OR, 0.50; 95% CrI, 0.30–0.87), BC (OR, 0.55; 95% CrI, 0.34–0.88), and normal saline (OR, 0.56; 95% CrI, 0.34–0.93). Meanwhile, H-HES was also associated with an increased risk of receiving RRT when compared with BC (OR, 0.51; 95% CrI, 0.27–0.93) and normal saline (OR, 0.52; 95% CrI, 0.24–0.96).

Conclusion

BCs, especially the Plasma-Lyte, are presumably the best choice for most critically ill patients who need fluid resuscitation. Meanwhile, the use of H-HES was associated with an increased incidence of AKI and risk of receiving RRT.

Registration

PROSPERO (CRD42017072728).

Recruitment of sublingual microcirculation using handheld incident dark field imaging as a routine measurement tool during the postoperative de-escalation phase-a pilot study in post ICU cardiac surgery patients

Background

Management of tissue perfusion following cardiac surgery is a challenging task where common clinical parameters do not reflect microcirculatory dysfunction. Heterogeneity in blood flow perfusion and abnormalities in capillary density characterize microcirculatory dysfunction. The restoration of a normal microcirculation may become a novel target for therapy in the future in addition to macrocirculatory parameters. The aim of this study is to determine how the sublingual microcirculatory parameters vary at the bedside in post-cardiac surgery patients which underwent diuretic therapy to correct fluid overload.

Methods

In this prospective observational pilot study, video clips of sublingual microcirculation in post-cardiac surgery patients receiving furosemide and/or spironolactone to achieve normal fluid balance were recorded using Cytocam-IDF imaging. Data was obtained on the first (T0), second (T1), and third (T2) day after the patients left the intensive care unit (ICU). Measurements were analyzed off-line to obtain the following microcirculatory parameters: total vessel density (TVD), microcirculatory flow index (MFI), proportion of perfused vessel (PPV), and perfused vessel density (PVD). Macrocirculatory parameters and body weight were also collected at these time points.

Results

Ninety measurements were performed in ten post ICU cardiac surgery patients. Thirteen measurements were excluded due to quality reasons; these excluded measurements were spread across the patients and time points, and there was no loss of patients or time points. An increase in TVD was observed from T0 to T1 (20 ± 2.7 to 24 ± 3.2 mm/mm²; p = 0.0410) and from T0 to T2 (20 ± 2.7 to 26 ± 3.3 mm/mm²; p = 0.0005). An increase in PVD was present from T0 to T1 (19 ± 2.3 to 24 ± 3.5 mm/mm²; p = 0.0072) and from T0 to T2 (19 ± 2.3 to 26 ± 3.4 mm/mm², p = 0.0008). Fluid overload was assessed through a positive cumulative fluid balance on the day of ICU discharge.

Conclusions

Cytocam-IDF imaging to monitor microcirculation as a daily parameter is feasible and could become a valuable tool to non-invasively assess the tissue oxygenation at the bedside. An increase in TVD and PVD (functional capillary density) indicated the recruitment of the sublingual microcirculation in patients with diuretic therapy. Future research is needed to prove the correlation between the recruitment of the sublingual microcirculation and the de-escalation phase of the fluid management.

Fluid therapy and shock: an integrative literature review

BACKGROUND

shock refers to a physiological situation that puts life at risk. Its early identification and the timely institution of therapeutic measures can avoid death. Despite the frequent administration of fluid therapy as a treatment for shock, the type and dose of fluids to be delivered remain undetermined.

AIM

to determine the type of fluids to be administered and the type of approach to be performed in the different types of shock.

METHOD

integrative literature review.

RESULTS

data about fluid therapy in hypovolaemic and distributive shock were obtained, specifically in the haemorrhagic and the septic types. None of the articles addressed cardiogenic shock.

CONCLUSION

hypotensive resuscitation, with blood, is the most appropriate approach in haemorrhagic shock. There remains a question regarding the best approach in septic shock. However, conservative fluid therapy seems to be appropriate, with preference given to the administration of balanced crystalloids or albumin as an alternative.

Microcirculation-mediated preconditioning and intracellular hypothermia

Microcirculation is a network of perfused capillaries that connects macrocirculation with the cells. Although research has provided insight into microcirculatory blood flow, our knowledge remains limited. In this article, we propose a new role of microcirculation in physiological and shock states. In healthy individuals, microcirculation maintains cellular homeostasis via preconditioning. When blood volume decreases, the ensuing microcirculatory changes result in heterogeneity of perfusion and tissue oxygenation. Initially, this is partly compensated by the preserved autoregulation and the increase in the metabolism rate of cells, but at later stages, the loss of autoregulation activates the cascade of intracellular hypothermia.

Applied Physiology of Fluid Resuscitation in Critical Illness

Fluids during resuscitation from shock increase mean systemic pressure and venous return. The pressure gradient for venous return must increase. Mean systemic pressure is the amount of vascular space in unstressed and stressed volume, mostly unstressed. Shock states can decrease mean systemic pressure by increasing unstressed volume, decreasing total blood volume, or decreasing the pressure gradient for venous return. Crystalloids across bodily spaces restore normal volume, whereas colloids remain in the intravascular space. Electrolyte content of fluids matters and excess chloride impairs renal blood flow. Albumin seems to be more effective at restoring blood volume in severe sepsis, but not in other conditions.

Normal saline for intravenous fluid therapy in critically ill patients

The efficacy and safety of normal saline (NS) for fluid therapy in critically ill patients remain controversy. In this review, we summarized the evidence of randomized controlled trials (RCTs) which compared NS with other solutions in critically ill patients. The results showed that when compared with 6% hydroxyethyl starch (HES), NS may reduce the onset of acute kidney injury (AKI). However, there is no significant different in mortality and incidence of AKI when compared with 10% HES, albumin and buffered crystalloid solution. Therefore, it is important to prescribe intravenous fluid for patients according to their individual condition.

Fluid resuscitation in critically ill patients-timing and dose matters

Fluid management is a complex subject in healthcare, particularly when pertaining to critically ill patients. Following a literature search on international recommendations regarding fluid administration for shocked patients, an audit was undertaken at Rotorua Public Hospital, New Zealand, to assess how the local fluid resuscitation strategy could be improved. The first part of the audit looked at the fluid resuscitation approach used to treat shocked patients admitted to the ICU of Rotorua Hospital in 2014 and changes required to achieve best practice recommendations. The second part tested the success and impact of the subsequently implemented, more measured approach to fluid resuscitation in 2016. Data was extracted from patient files, fluid charts and electronic records to assess fluid administration and de-escalation measures. The collated information was analysed and compared to recommendations found in the literature. The complete audit cycle revealed not only a significant improvement in adherence to best practice guidelines, but also an association with better patient outcomes.