The association between fluid balance and outcomes after subarachnoid hemorrhage

Contemporary management of aneurysmal subarachnoid haemorrhage. An update for the intensivist

Aneurysmal subarachnoid haemorrhage (aSAH) is a rare yet profoundly debilitating condition associated with high global case fatality and morbidity rates. The key determinants of functional outcome include early brain injury, rebleeding of the ruptured aneurysm and delayed cerebral ischaemia. The only effective way to reduce the risk of rebleeding is to secure the ruptured aneurysm quickly. Prompt diagnosis, transfer to specialized centers, and meticulous management in the intensive care unit (ICU) significantly improved the prognosis of aSAH. Recently, multimodality monitoring with specific interventions to correct pathophysiological imbalances has been proposed. Vigilance extends beyond intracranial concerns to encompass systemic respiratory and haemodynamic monitoring, as derangements in these systems can precipitate secondary brain damage. Challenges persist in treating aSAH patients, exacerbated by a paucity of robust clinical evidence, with many interventions showing no benefit when tested in rigorous clinical trials. Given the growing body of literature in this field and the issuance of contemporary guidelines, our objective is to furnish an updated review of essential principles of ICU management for this patient population. Our review will discuss the epidemiology, initial stabilization, treatment strategies, long-term prognostic factors, the identification and management of post-aSAH complications. We aim to offer practical clinical guidance to intensivists, grounded in current evidence and expert clinical experience, while adhering to a concise format.

Prevention and Correction of Dysnatremia After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Dysnatremia occurs commonly in patients with aneurysmal subarachnoid hemorrhage (aSAH). The mechanisms for development of sodium dyshomeostasis are complex, including the cerebral salt-wasting syndrome, the syndrome of inappropriate secretion of antidiuretic hormone, diabetes insipidus. Iatrogenic occurrence of altered sodium levels plays a role, as sodium homeostasis is tightly linked to fluid and volume management.

METHODS

Narrative review of the literature.

RESULTS

Many studies have aimed to identify factors predictive of the development of dysnatremia, but data on associations between dysnatremia and demographic and clinical variables are variable. Furthermore, although a clear relationship between serum sodium serum concentrations and outcomes has not been established-poor outcomes have been associated with both hyponatremia and hypernatremia in the immediate period following aSAH and set the basis for seeking interventions to correct dysnatremia. While sodium supplementation and mineralocorticoids are frequently administered to prevent or counter natriuresis and hyponatremia, evidence to date is insufficient to gauge the effect of such treatment on outcomes.

CONCLUSIONS

In this article, we reviewed available data and provide a practical interpretation of these data as a complement to the newly issued guidelines for management of aSAH. Gaps in knowledge and future directions are discussed.

Insights into Hemodynamic Features of Survivors and the Deceased with Acute Brain Injury: A Step Forward Tailored Treatment

BACKGROUND

Pulmonary artery catheters are widely used for hemodynamical monitoring in critically ill patients. Acute brain injury is among the severe conditions treated in an intensive care unit. The advanced monitoring of hemodynamical parameters, fluid balance and adequate administered treatment based on those values are components of goal-directed therapy.

METHODS

A prospective observational study included adult patients who were hospitalized in the ICU due to acute bran injury, excluding brain oedema after cardiac arrest. Each patient had PAC inserted and hemodynamic data were collected during the first 3 days of the ICU stay every 6 h. Patients were divided into two groups based on the endpoint: the survivors and the deceased.

RESULTS

Length of stay in hospital differed between patiens. All patients, regardless of their outcome, had noradrenaline administered. The initial values of PAP differed between the groups (p = 0.05). There were positive correlations noticed between noradrenaline dose, CVP and fluid balance when compared to PCWP in a group of survivors and a positive correlation in the fluid balance when compared to PAP and PVRI. Lactate serum concentrations presented a correlation with the dose of noradrenaline in both groups.

CONCLUSIONS

Upon acute brain injury, values of PVRI and PAP increase. This is corelated with fluid load and worsened by an excessive fluid treatment in the case of an inconsiderate approach for stabilizing the patient hemodynamically. PAC may present limited advantages in terms of PAP and PVRI control during the treatment.

The effect of the volemic and cardiac status on brain oxygenation in patients with subarachnoid hemorrhage: a bi-center cohort study

Background

Fluid management in patients after subarachnoid hemorrhage (SAH) aims at the optimization of cerebral blood flow and brain oxygenation. In this study, we investigated the effects of hemodynamic management on brain oxygenation by integrating advanced hemodynamic and invasive neuromonitoring.

Methods

This observational cohort bi-center study included data of consecutive poor-grade SAH patients who underwent pulse contour cardiac output (PiCCO) monitoring and invasive neuromonitoring. Fluid management was guided by the transpulmonary thermodilution system and aimed at euvolemia (cardiac index, CI ≥ 3.0 L/min/m²; global end-diastolic index, GEDI 680–800 mL/m²; stroke volume variation, SVV < 10%). Patients were managed using a brain tissue oxygenation (P_btO₂) targeted protocol to prevent brain tissue hypoxia (BTH, P_btO₂ < 20 mmHg). To assess the association between CI and P_btO₂ and the effect of fluid challenges on CI and P_btO₂, we used generalized estimating equations to account for repeated measurements.

Results

Among a total of 60 included patients (median age 56 [IQRs 47–65] years), BTH occurred in 23% of  the monitoring time during the first 10 days since admission. Overall, mean CI was within normal ranges (ranging from 3.1 ± 1.3 on day 0 to 4.1 ± 1.1 L/min/m² on day 4). Higher CI levels were associated with higher P_btO₂ levels (Wald = 14.2; p < 0.001). Neither daily fluid input nor fluid balance was associated with absolute P_btO₂ levels (p = 0.94 and p = 0.85, respectively) or the occurrence of BTH (p = 0.68 and p = 0.71, respectively). P_btO₂ levels were not significantly different in preload dependent patients compared to episodes of euvolemia. P_btO₂ increased as a response to fluid boluses only if BTH was present at baseline (from 13 ± 6 to 16 ± 11 mmHg, OR = 13.3 [95% CI 2.6–67.4], p = 0.002), but not when all boluses were considered (p = 0.154).

Conclusions

In this study a moderate association between increased cardiac output and brain oxygenation was observed. Fluid challenges may improve P_btO₂ only in the presence of baseline BTH. Individualized hemodynamic management requires advanced cardiac and brain monitoring in critically ill SAH patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00960-z.

Impact of Early Fluid Balance on Long-Term Mortality in Critically Ill Surgical Patients: A Retrospective Cohort Study in Central Taiwan

Fluid balance is an essential issue in critical care; however, the impact of early fluid balance on the long-term mortality in critically ill surgical patients remains unknown. This study aimed to address the impact of day 1–3 and day 4–7 fluid balance on the long-term mortality in critically ill surgical patients. We enrolled patients who were admitted to surgical intensive care units (ICUs) during 2015–2019 at a tertiary hospital in central Taiwan and retrieved date-of-death from the Taiwanese nationwide death registration profile. We used a Log-rank test and a multivariable Cox proportional hazards regression model to determine the independent mortality impact of early fluid balance. A total of 6978 patients were included for analyses (mean age: 60.9 ± 15.9 years; 63.9% of them were men). In-hospital mortality, 90-day mortality, 1-year and overall mortality was 10.3%, 15.8%, 23.8% and 31.7%, respectively. In a multivariable Cox proportional hazard regression model adjusted for relevant covariates, we found that positive cumulative day 4–7 fluid balance was independently associated with long-term mortality (aHR 1.083, 95% CI 1.062–1.105), and a similar trend was found on day 1–3 fluid balance, although to a lesser extent (aHR 1.027, 95% CI 1.011–1.043). In conclusion, the fluid balance in the first week of ICU stay, particularly day 4–7 fluid balance, may affect the long-term outcome in critically ill surgical patients.

Fluid management in patients undergoing neurosurgery

Fluid management is an important component of perioperative care for patients undergoing neurosurgery. The primary goal of fluid management in neurosurgery is the maintenance of normovolemia and prevention of serum osmolarity reduction. To maintain normovolemia, it is important to administer fluids in appropriate amounts following appropriate methods, and to prevent a decrease in serum osmolarity, the choice of fluid is essential. There is considerable debate about the choice and optimal amounts of fluids administered in the perioperative period. However, there is little high-quality clinical research on fluid therapy for patients undergoing neurosurgery. This review will discuss the choice and optimal amounts of fluids in neurosurgical patients based on the literature, recent issues, and perioperative fluid management practices.

Bioreactance-Based Noninvasive Fluid Responsiveness and Cardiac Output Monitoring: A Pilot Study in Patients with Aneurysmal Subarachnoid Hemorrhage and Literature Review

Management of volume status, arterial blood pressure, and cardiac output are core elements in approaching the patients with aneurysmal subarachnoid hemorrhage (SAH). For the prevention and treatment of delayed cerebral ischemia (DCI), euvolemia is advocated and caution is made towards the avoidance of hypervolemia. Induced hypertension and cardiac output augmentation are the mainstays of medical management during active DCI, whereas the older triple-H paradigm has fallen out of favor due to lack of demonstrable physiological or clinical benefits and serious concern for adverse effects such as pulmonary edema and multiorgan system dysfunction. Furthermore, insight into clinical hemodynamics of patients with SAH becomes salient when one considers the frequently associated cardiac and pulmonary manifestations of the disease such as SAH-associated cardiomyopathy and neurogenic pulmonary edema. In terms of fluid and volume targets, less attention has been paid to dynamic markers of fluid responsiveness despite the well-established, in the general critical care literature, superiority of these as compared to traditionally used static markers such as central venous pressure (CVP). Based on this literature and sound pathophysiologic reasoning, reliance on static markers (such as CVP) is unjustified when one attempts to assess strategies augmenting stroke volume (SV), arterial blood pressure, and oxygen delivery. There are several options for continuous bedside cardiorespiratory monitoring and optimization of SAH patients. We, here, review a noninvasive monitoring technique based on thoracic bioreactance and focusing on continuous cardiac output and fluid responsiveness markers.

Assessment of two prophylactic fluid strategies in aneurysmal subarachnoid hemorrhage: A randomized trial

OBJECTIVE

To compare the effect of two prophylactic euvolemic fluid strategy regimens on the incidence of cerebral vasospasm and clinical outcomes in patients with aneurysmal subarachnoid hemorrhage (SAH).

METHODS

Ninety-six patients with a basal intravenous intake of 15 mL/kg/day of Ringer's lactate solution were included, and an additional 15 to 50 mL/kg/day Ringer's lactate (RL-group) or hydroxyethyl starch 130/0.4 solution (HES-group) was administered to maintain the targeted mean arterial pressure. The primary end point was the occurrence of cerebral vasospasm during the first 14 days. The secondary end points were case fatality, Barthel's index, and Glasgow Outcome Scores (GOS) at 30 days after SAH.

RESULTS

Cerebral vasospasm developed in 42 patients (43.7%), and nine of these events were severe. The vasospasm rate among the RL- and HES-based groups was 25/48 and 17/48, respectively. For the secondary endpoint, four patients (4%) died by the end of follow-up (two in each group). Unfavorable outcome cases were not different in the RL and HES groups (9 vs. 14, respectively). There was no difference between the Barthel's scores at 30 days between the two groups.

CONCLUSIONS

Using starches in a prophylactic treatment strategy in aneurysmal SAH in not supported by the study.The trial was registered at Clinicaltrials.gov under the number NCT02064075.

High Early Fluid Input After Aneurysmal Subarachnoid Hemorrhage: Combined Report of Association With Delayed Cerebral Ischemia and Feasibility of Cardiac Output-Guided Fluid Restriction

BACKGROUND

Guidelines on the management of aneurysmal subarachnoid hemorrhage (aSAH) recommend euvolemia, whereas hypervolemia may cause harm. We investigated whether high early fluid input is associated with delayed cerebral ischemia (DCI), and if fluid input can be safely decreased using transpulmonary thermodilution (TPT).

METHODS

We retrospectively included aSAH patients treated at an academic intensive care unit (2007-2011; cohort 1) or managed with TPT (2011-2013; cohort 2). Local guidelines recommended fluid input of 3 L daily. More fluids were administered when daily fluid balance fell below +500 mL. In cohort 2, fluid input in high-risk patients was guided by cardiac output measured by TPT per a strict protocol. Associations of fluid input and balance with DCI were analyzed with multivariable logistic regression (cohort 1), and changes in hemodynamic indices after institution of TPT assessed with linear mixed models (cohort 2).

RESULTS

Cumulative fluid input 0 to 72 hours after admission was associated with DCI in cohort 1 (n=223; odds ratio [OR] 1.19/L; 95% confidence interval 1.07-1.32), whereas cumulative fluid balance was not. In cohort 2 (23 patients), using TPT fluid input could be decreased from 6.0 ± 1.0 L before to 3.4 ± 0.3 L; P = .012), while preload parameters and consciousness remained stable.

CONCLUSION

High early fluid input was associated with DCI. Invasive hemodynamic monitoring was feasible to reduce fluid input while maintaining preload. These results indicate that fluid loading beyond a normal preload occurs, may increase DCI risk, and can be minimized with TPT.

Fluid Balance Variations During the Early Phase of Large Hemispheric Stroke Are Associated With Patients' Functional Outcome

Background: From the variety of factors underlying the ischemia-associated edema formation in large hemispheric stroke (LHS), an increased brain water content during the early phase seems to have a pivotal role for long-lasting tissue damage. However, the importance of the fluid management during the acute phase of LHS has so far not been adequately studied. Therefore, this study explored the association between the fluid balance and functional outcome in patients suffering from LHS. Methods: We analyzed hospital-based medical records of 39 consecutive patients with LHS and decompressive hemicraniectomy. Over the first 10 days after admission, the volumes of all administered fluids were assessed daily and corrected for daily urinary output and insensible loss. Functional outcome at 3 months was assessed with the modified Rankin Scale (mRS) and dichotomized into an acceptable (mRS ≤ 4) vs. a poor outcome (mRS ≥ 5). Results: Compared to patients with a poor functional outcome (n = 19), those with an acceptable outcome (n = 20) were characterized by a significantly lower cumulative net fluid balance at day 5 (1.6 ± 2.5 vs. 3.4 ± 4.4 l), day 7 (2.0 ± 2.9 vs. 4.6 ± 5.2 l), and day 10 (0 ± 2.5 vs. 5.6 ± 6.2 l). In addition to age, only the cumulative net fluid balance at day 10 served as an independent factor for poor functional outcome in multiple regression analyses. Conclusion: These data provide evidence for a critical role of the early phase net fluid balance with respect to the functional outcome after LHS. This observation leads to the hypothesis that patients with LHS might benefit from a more restrictive volume therapy. However, prospective studies are warranted to establish a causal relationship and recommendations for treatment strategies.

Fluid Intake But Not Fluid Balance Is Associated With Poor Outcome in Nontraumatic Subarachnoid Hemorrhage Patients

OBJECTIVES

Optimal fluid management is important in patients with acute brain injury, including subarachnoid hemorrhage. We aimed to examine the relationship between daily fluid intake and fluid balance with hospital complications and functional outcome.

DESIGN

Retrospective observational cohort study.

SETTING

Neurocritical care unit at a tertiary academic medical center.

PATIENTS

Two-hundred thirty-seven consecutive nontraumatic subarachnoid hemorrhage patients admitted to the neurologic ICU between 2010 and 2016.

INTERVENTIONS

Total daily amount of fluids and fluid balance were calculated over 15 days. Using multivariate generalized estimating equation models the association of daily fluid intake and fluid balance with disease severity, hospital complications and poor functional outcome (3-mo modified Rankin Score ≥ 3) was investigated. Additionally, we described the composition of fluids given.

MEASUREMENTS AND MAIN RESULTS

Patients presented with a median admission Hunt and Hess grade of 3 (interquartile range, 1-5) and were 57 years old (interquartile range, 47-67 yr old). A higher daily fluid intake was associated with higher admission Hunt and Hess grade (odds ratio, 1.61; 95% CI, 1.47-1.76; p < 0.001), increased pulmonary fluid accumulation (adjusted odds ratio, 1.11; 95% CI, 1.01-1.21; p = 0.033), prolonged mechanical ventilation (Wald statistic = 20.08; degrees of freedom = 1; p < 0.001), higher daily Subarachnoid hemorrhage Early Brain Edema Score (adjusted odds ratio, 1.11; 95% CI, 1.01-1.22; p = 0.034), occurrence of anemia (adjusted odds ratio, 1.36; 95% CI, 1.20-1.54; p < 0.001), delayed cerebral ischemia (adjusted odds ratio, 1.31; 95% CI, 1.14-1.51; p < 0.001), and poor functional outcome (adjusted odds ratio, 1.25; 95% CI, 1.10-1.41; p < 0.001). Daily fluid balance was associated with higher admission Hunt and Hess grade (odds ratio, 1.09; 95% CI, 1.05-1.13; p < 0.001) and anemia (adjusted odds ratio, 1.17; 95% CI, 1.03-1.33; p = 0.019). The main contributors to fluids were nutritional compounds (31%), IV drugs (30%), and volume substitution (17%).

CONCLUSIONS

Our study demonstrates a significant association of fluid intake but not fluid balance with hospital complications and poor functional outcome in subarachnoid hemorrhage patients. A larger prospective study is needed to confirm our results.

Importance of Managing the Water-Electrolyte Balance by Delivering the Optimal Minimum Amount of Water and Sodium After Subarachnoid Hemorrhage

BACKGROUND

After aneurysmal subarachnoid hemorrhage (aSAH), crystalloid fluids with a relatively high sodium concentration have been used to maintain the cerebral blood flow. However, the prophylactic delivery of water and sodium by intravenous (IV) infusion will not necessarily improve the prognosis of patients after aSAH, and the excessive supply of water and sodium can negatively affect the outcome. We hypothesized that the delivery of an optimal amount of water and sodium separately might improve the outcome after aSAH.

METHODS

We recruited 55 consecutive patients who had undergone clipping or endovascular coil embolization after aSAH. Group 1 (n = 33) received conventional therapy (i.e., prophylactic IV sodium and water [protocol 1]). Group 2 (n = 22) received the optimal amount of water and sodium separately (protocol 2).

RESULTS

The median total of water and sodium chloride supplied in group 1 was significantly greater than that supplied in group 2 (P < 0.01). The modified Rankin scale score at discharge was 0-2 in 15 patients (95%) in group 2 and 23 patients (55%) in group 1 (P < 0.001). On multivariate logistic regression analysis, the odds ratio for a discharge modified Rankin scale score of 0-2 or 3-6 was significantly associated with the treatment protocol (P < 0.05) and the net fluid balance on days 4-8 (P < 0.05).

CONCLUSION

The separate delivery of optimal amounts of water and sodium could be a promising therapeutic strategy to improve the prognosis after aSAH.

The downside of aggressive volume administration in critically ill patients-"aggressive" may lead to "excessive"

Management of fluid therapy in an intensive care unit (ICU) tends to be volume restriction after initial fluid resuscitation, since it has been the consensus that volume overload is associated with complications and poor clinical outcomes. Aggressive volume administration without cautious monitoring should be avoided in the ICU, because it could lead to excessive volume administration. However, there are limited consensus on determining the completion of resuscitation phase, in other words, when to stop aggressive infusion and initiate infusion restriction.

Positive fluid balance is associated with increased in-hospital mortality in patients with intracerebral hemorrhage

Objective: This study aimed to investigate the association between fluid balance (FB) and in-hospital mortality in patients with intracerebral hemorrhage (ICH).Methods: Data were extracted from the online database Multi-parameter Intelligent Monitoring in Intensive Care III. Patients were divided into two groups according to the FB status at 48 hours after intensive care unit (ICU) admission: negative and positive 48-hour FB groups. The primary outcome was in-hospital mortality.Results: Data of 1407 patients were analyzed. Linear spline function in logistic models showed significant association between the volume of positive FB and in-hospital mortality (odds ratio (OR) 1.006; 95% CI: 1.002-1.010), while the association between the volume of negative FB and in-hospital mortality was non-significant. For interpretation, FB was further divided into four quartiles. Referred to Q1, the OR of in-hospital mortality stepwise increased from Q2 (OR, 1.11; 95% CI: 0.72-1.68) to Q4 (OR, 1.68; 95% CI: 1.13-2.48). A similar association was also found between FB and Glasgow coma scale at ICU discharge.Conclusions: In patients with ICH, increased volume of positive FB was associated with higher in-hospital mortality while the volume of negative FB was not. Whether maintaining a zero FB status is a beneficial strategy needs further investigation.

High Early Fluid Input After Aneurysmal Subarachnoid Hemorrhage: Combined Report of Association With Delayed Cerebral Ischemia and Feasibility of Cardiac Output-Guided Fluid Restriction

BACKGROUND

Guidelines on the management of aneurysmal subarachnoid hemorrhage (aSAH) recommend euvolemia, whereas hypervolemia may cause harm. We investigated whether high early fluid input is associated with delayed cerebral ischemia (DCI), and if fluid input can be safely decreased using transpulmonary thermodilution (TPT).

METHODS

We retrospectively included aSAH patients treated at an academic intensive care unit (2007-2011; cohort 1) or managed with TPT (2011-2013; cohort 2). Local guidelines recommended fluid input of 3 L daily. More fluids were administered when daily fluid balance fell below +500 mL. In cohort 2, fluid input in high-risk patients was guided by cardiac output measured by TPT per a strict protocol. Associations of fluid input and balance with DCI were analyzed with multivariable logistic regression (cohort 1), and changes in hemodynamic indices after institution of TPT assessed with linear mixed models (cohort 2).

RESULTS

Cumulative fluid input 0 to 72 hours after admission was associated with DCI in cohort 1 (n=223; odds ratio [OR] 1.19/L; 95% confidence interval 1.07-1.32), whereas cumulative fluid balance was not. In cohort 2 (23 patients), using TPT fluid input could be decreased from 6.0 ± 1.0 L before to 3.4 ± 0.3 L; P = .012), while preload parameters and consciousness remained stable.

CONCLUSION

High early fluid input was associated with DCI. Invasive hemodynamic monitoring was feasible to reduce fluid input while maintaining preload. These results indicate that fluid loading beyond a normal preload occurs, may increase DCI risk, and can be minimized with TPT.

Neurologic Intensive Care Unit Electrolyte Management

Dysnatremia is a common finding in the intensive care unit (ICU) and may be a predictor for mortality and poor clinical outcomes. Depending on the time of onset (ie, on admission vs later in the ICU stay), the incidence of dysnatremias in critically ill patients ranges from 6.9% to 15%, respectively. The symptoms of sodium derangement and their effect on brain physiology make early recognition and correction paramount in the neurologic ICU. Hyponatremia in brain injured patients can lead to life-threatening conditions such as seizures and may worsen cerebral edema and contribute to alterations in intracranial pressure.

Fluid management of the neurological patient: a concise review

Maintenance fluids in critically ill brain-injured patients are part of routine critical care. Both the amounts of fluid volumes infused and the type and tonicity of maintenance fluids are relevant in understanding the impact of fluids on the pathophysiology of secondary brain injuries in these patients. In this narrative review, current evidence on routine fluid management of critically ill brain-injured patients and use of haemodynamic monitoring is summarized. Pertinent guidelines and consensus statements on fluid management for brain-injured patients are highlighted. In general, existing guidelines indicate that fluid management in these neurocritical care patients should be targeted at euvolemia using isotonic fluids. A critical appraisal is made of the available literature regarding the appropriate amount of fluids, haemodynamic monitoring and which types of fluids should be administered or avoided and a practical approach to fluid management is elaborated. Although hypovolemia is bound to contribute to secondary brain injury, some more recent data have emerged indicating the potential risks of fluid overload. However, it is acknowledged that many factors govern the relationship between fluid management and cerebral blood flow and oxygenation and more research seems warranted to optimise fluid management and improve outcomes.

Poor outcome is associated with less negative fluid balance in patients with aneurysmal subarachnoid hemorrhage treated with prophylactic vasopressor-induced hypertension

Background

Aneurysmal subarachnoid hemorrhage (SAH) is a serious condition associated with high mortality rates and long-term disability. We investigated the impact of fluid balance on neurologic outcome after adjustment for possible confounders related to intensive care therapy and extra-cerebral organ failure during the early phase after SAH.

Methods

In this retrospective study, we analyzed data from all 142 adult patients admitted to our university hospital surgical intensive care unit (ICU) with SAH between March 2004 and November 2010.

Results

The mean patient age was 54 ± 14 years, 62.7 % were female, and the median Hunt and Hess score was 3. The proportions of patients with poor outcome (Glasgow Outcome Score ≤3) were 58.4, 54.2, and 52.1 % at 3, 6, and 12 months, respectively, after the SAH. The ICU and hospital mortality rates were both 12.7 %, and the median lengths of stay in the ICU and the hospital were 16 (IQ 7–25) and 26 (IQ 18–34) days, respectively. In multivariable analysis, older age and greater cumulative fluid balance within the first 7 days in the ICU were independently associated with a greater risk of poor outcome.

Conclusion

In this cohort of patients, older age and greater cumulative fluid balance were independently associated with a greater risk of poor outcome up to 1 year after the initial insult. Our data suggest that mild hypovolemia may be beneficial in the management of these patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-016-0128-6) contains supplementary material, which is available to authorized users.

Assessment of circulating blood volume with fluid administration targeting euvolemia or hypervolemia

BACKGROUND

The occurrence of hypovolemia in the setting of cerebral vasospasm reportedly increases the risk for delayed ischemic neurologic deficits. Few studies have objectively assessed blood volume (BV) in response to fluid administration targeting normovolemia (NV) or hypervolemia (HV) and none have done so with crystalloids alone. The primary purpose was to evaluate the BV of patients with SAH receiving crystalloid fluid administration targeting NV or HV.

METHODS

The University of Washington IRB approved the study. Prospectively collected data was obtained from patients enrolled in a clinical trial and a concurrent group of patients who received IV fluids during the ICU stay. We defined a normovolemia (NV) and hypervolemia (HV) group based on the cumulative amount of IV fluid administered in mL/kg from ICU admission to day 5; ≥30-60 mL/kg/day (NV) and ≥60 mL/kg/day (HV), respectively. In a subgroup of patients, BV was measured on day 5 post ictus using iodinated (131)I-labeled albumin injection and the BVA-100 (Daxor Corp, New York, NY). Differences between the NV and HV groups were compared using Student's t-test with assumption for unequal variance.

RESULTS

Twenty patients in the NV and 19 in the HV groups were included. The HV group received more fluid and had a higher fluid balance than the NV group. The subgroup of patients in whom BV was measured on day 5 (n = 19) was not different from the remainder of the cohort with respect to the total amount of administered fluid and net cumulative fluid balance by day 5. BV was not different between the two groups and varied widely.

CONCLUSIONS

Routinely targeting prophylactic HV using crystalloids does not result in a higher circulating BV compared to targeting NV, but the possibility of clinically unrecognized hypovolemia remains.

Positive Fluid Balance Is Associated With Poor Outcomes in Subarachnoid Hemorrhage

BACKGROUND

Strict maintenance of normovolemia is standard of care in the treatment of aneurysmal subarachnoid hemorrhage (aSAH), and induced hypervolemia is often used to treat delayed cerebral ischemia from vasospasm. We tested the hypothesis that positive fluid balance could adversely affect clinical outcomes in aSAH.

METHODS

We reviewed 288 patients with aSAH admitted to the Neuroscience Intensive Care Unit (NICU) from October 2001 to June 2011. We collected data on fluid balance during NICU stay, clinical and radiographic evidence of vasospasm, cardiopulmonary complications, and functional outcomes by modified Rankin Scale (mRS) on follow-up (mean 8 ± 8 months). Poor functional outcome was defined as an mRS score 3-6. Associations of variables of interest with outcome were assessed using univariable and multivariable logistic regression. Propensity scores were estimated to account for imbalances between patients with positive versus negative fluid balance and were included in multivariable models.

RESULTS

Average net fluid balance during the NICU stay was greater in patients with poor functional outcome (3.52 ± 5.51 L versus -.02 ± 5.30 L in patients with good outcome; P < .001). On multivariate analysis, positive fluid balance (P = .002) was independently associated with poor functional outcome along with World Federation of Neurosurgical Societies grade (P < .001), transfusion (P = .003), maximum glucose (P = .005), and radiological evidence of cerebral infarction (P = .008). After regression adjustment with propensity scores, the association of positive fluid balance with poor functional outcome remained significant (odds ratio, 1.18; 95% confidence interval, 1.08-1.29; P < .001).

CONCLUSIONS

Greater positive net fluid balance is independently associated with poorer functional outcome in patients with aSAH.

Association between fluid balance and survival in critically ill patients

OBJECTIVE

Although the consequences of chronic fluid retention are well known, those of iatrogenic fluid retention that occurs during critical illness have not been fully determined. Therefore, we investigated the association between fluid balance and survival in a cohort of almost 16,000 individuals who survived an intensive care unit (ICU) stay in a large, urban, tertiary medical centre.

DESIGN

Longitudinal analysis of fluid balance at ICU discharge and 90-day post-ICU survival.

MEASUREMENTS

Associations between fluid balance during the ICU stay, determined from the electronic bedside record, and survival were tested using Cox proportional hazard models adjusted for severity of critical illness.

RESULTS

There were 1827 deaths in the first 90 days after ICU discharge. Compared with the lowest quartile of discharge fluid balance [median (interquartile range) -1.5 (-3.1, -0.7) L], the highest quartile [7.6 (5.7, 10.8) L] was associated with a 35% [95% confidence interval (CI) 1.13-1.61)] higher adjusted risk of death. Fluid balance was not associated with outcome amongst individuals without congestive heart failure or renal dysfunction. Amongst patients with either comorbidity, however, fluid balance was strongly associated with outcome, with the highest quartile having a 55% (95% CI 1.24-1.95) higher adjusted risk of death than the lowest quartile. Isotonic fluid balance, defined as the difference between intravenous isotonic fluid administration and urine output, was similarly associated with 90-day outcomes.

CONCLUSION

Positive fluid balance at the time of ICU discharge is associated with increased risk of death, after adjusting for markers of illness severity and chronic medical conditions, particularly in patients with underlying heart or kidney disease. Restoration of euvolaemia prior to discharge may improve survival after acute illness.

Fluid overload in patients with severe sepsis and septic shock treated with early goal-directed therapy is associated with increased acute need for fluid-related medical interventions and hospital death

Early goal-directed therapy (EGDT) consists of early, aggressive fluid resuscitation and is known to improve survival in sepsis. It is unknown how often EGDT leads to subsequent fluid overload and whether post-EGDT fluid overload affects patients' outcomes. Our hypothesis was that patients with sepsis treated with EGDT were at risk for fluid overload and that fluid overload would be associated with adverse outcomes. We conducted a retrospective cohort of 405 consecutive patients admitted with severe sepsis and septic shock to the medical intensive care unit of a tertiary care academic hospital from January 2008 to December 2009. Baseline demographics, daily weights, fluid status, clinical or radiographic evidence of fluid overload, and medical interventions (thoracentesis, paracentesis, diuretic use, and ultrafiltration) were abstracted, and associations explored using univariate and multivariate logistic and linear regression analyses. At day 1, 67% of patients developed evidence of fluid overload, and in 48%, fluid overload persisted to day 3. Interrater agreement for presence of fluid overload was substantial (κ = 0.7). An increased trend in weight was noted in those with persistent clinical and radiologic evidence of fluid overload, but not with recorded positive fluid balance. When adjusted for baseline severity of illness, fluid overload was associated with increased use of fluid-related medical interventions (thoracentesis and diuretics) and hospital mortality (odds ratio, 1.92; confidence interval, 1.16-3.22). In patients with severe sepsis and septic shock treated with EGDT, clinical evidence of persistent fluid overload is common and is associated with increased use of medical interventions and hospital mortality.

The effects of fluid balance and colloid administration on outcomes in patients with aneurysmal subarachnoid hemorrhage: a propensity score-matched analysis

BACKGROUND

Delayed ischemic neurological deficit (DIND) following aneurysmal subarachnoid hemorrhage (SAH) remains a significant cause of mortality and disability. The administration of colloids and the induction of a positive fluid balance during the vasospasm risk period remain controversial. Here, we compared DIND and outcomes among propensity score-matched cohorts who did and did not receive colloids and also tested the effect of a positive fluid balance on these endpoints.

METHODS

Exploratory analysis was performed on 413 patients enrolled in CONSCIOUS-1, a prospective randomized trial of clazosentan for the prevention of angiographic vasospasm. Propensity score matching was performed on the basis of age, gender, pre-existing heart conditions, hypertension, nicotine use, World Federation of Neurosurgical Societies scores, aneurysm location, clazosentan treatment, subarachnoid clot burden, and severity of angiographic vasospasm. Inferential statistics were used for group-wise comparisons.

RESULTS

One hundred twenty-three subjects were matched (41 received colloids, whereas 82 did not). The covariate balance and propensity score distributions were acceptable. There was no difference between the groups with respect to DIND (17 vs. 22%; p = 0.64) or the presence (48 vs. 51%; p = 0.71) or volume of delayed infarcts (volume >7.5 cm3; 62 vs. 48%; p = 0.41). Similarly, no differences were found on multivariate analysis between patients who did and did not have a positive fluid balance, although patients with severe angiographic vasospasm had more delayed infarcts with a negative fluid balance (p = 0.01). Among all subjects, the administration of colloids and a positive fluid balance were associated with worse outcomes on the NIHSS (p = 0.04) and modified Rankin (p = 0.02) scales, respectively.

CONCLUSIONS

Colloid administration and induction of a positive fluid balance during the vasospasm risk period may be associated with poor outcomes in specific patient groups. Patient selection is of utmost importance when managing the fluid status of patients with aneurysmal SAH.