Hypertonic saline in critical illness - A systematic review

European Society of Intensive Care Medicine clinical practice guideline on fluid therapy in adult critically ill patients. Part 1: the choice of resuscitation fluids

PURPOSE

This is the first of three parts of the clinical practice guideline from the European Society of Intensive Care Medicine (ESICM) on resuscitation fluids in adult critically ill patients. This part addresses fluid choice and the other two will separately address fluid amount and fluid removal.

METHODS

This guideline was formulated by an international panel of clinical experts and methodologists. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was applied to evaluate the certainty of evidence and to move from evidence to decision.

RESULTS

For volume expansion, the guideline provides conditional recommendations for using crystalloids rather than albumin in critically ill patients in general (moderate certainty of evidence), in patients with sepsis (moderate certainty of evidence), in patients with acute respiratory failure (very low certainty of evidence) and in patients in the perioperative period and patients at risk for bleeding (very low certainty of evidence). There is a conditional recommendation for using isotonic saline rather than albumin in patients with traumatic brain injury (very low certainty of evidence). There is a conditional recommendation for using albumin rather than crystalloids in patients with cirrhosis (very low certainty of evidence). The guideline provides conditional recommendations for using balanced crystalloids rather than isotonic saline in critically ill patients in general (low certainty of evidence), in patients with sepsis (low certainty of evidence) and in patients with kidney injury (very low certainty of evidence). There is a conditional recommendation for using isotonic saline rather than balanced crystalloids in patients with traumatic brain injury (very low certainty of evidence). There is a conditional recommendation for using isotonic crystalloids rather than small-volume hypertonic crystalloids in critically ill patients in general (very low certainty of evidence).

CONCLUSIONS

This guideline provides eleven recommendations to inform clinicians on resuscitation fluid choice in critically ill patients.

Hypertonic saline infusion does not improve the chance of primary fascial closure after damage control laparotomy: a randomized controlled trial

BACKGROUND

Previous observational studies showed higher rates of abdominal wall closure with the use of hypertonic saline in trauma patients with abdominal injuries. However, no randomized controlled trials have been performed on this matter. This double-blind randomized clinical trial assessed the effect of 3% hypertonic saline (HS) solution on primary fascial closure and the timing of abdominal wall closure among patients who underwent damage control laparotomy for bleeding control.

METHODS

Double-blind randomized clinical trial. Patients with abdominal injuries requiring damage control laparotomy (DCL) were randomly allocated to receive a 72-h infusion (rate: 50 mL/h) of 3% HS or 0.9 N isotonic saline (NS) after the index DCL. The primary endpoint was the proportion of patients with abdominal wall closure in the first seven days after the index DCL.

RESULTS

The study was suspended in the first interim analysis because of futility. A total of 52 patients were included. Of these, 27 and 25 were randomly allocated to NS and HS, respectively. There were no significant differences in the rates of abdominal wall closure between groups (HS: 19 [79.2%] vs. NS: 17 [70.8%]; p = 0.71). In contrast, significantly higher hypernatremia rates were observed in the HS group (HS: 11 [44%] vs. NS: 1 [3.7%]; p < 0.001).

CONCLUSION

This double-blind randomized clinical trial showed no benefit of HS solution in primary fascial closure rates. Patients randomized to HS had higher sodium concentrations after the first day and were more likely to present hypernatremia. We do not recommend using HS in patients undergoing damage control laparotomy. Trial registration The trial protocol was registered in clinicaltrials.gov (identifier: NCT02542241).

Advantages and limitations of experimental autoimmune encephalomyelitis in breaking down the role of the gut microbiome in multiple sclerosis

Since the first model of experimental autoimmune encephalomyelitis (EAE) was introduced almost a century ago, there has been an ongoing scientific debate about the risks and benefits of using EAE as a model of multiple sclerosis (MS). While there are notable limitations of translating EAE studies directly to human patients, EAE continues to be the most widely used model of MS, and EAE studies have contributed to multiple key breakthroughs in our understanding of MS pathogenesis and discovery of MS therapeutics. In addition, insights from EAE have led to a better understanding of modifiable environmental factors that can influence MS initiation and progression. In this review, we discuss how MS patient and EAE studies compare in our learning about the role of gut microbiome, diet, alcohol, probiotics, antibiotics, and fecal microbiome transplant in neuroinflammation. Ultimately, the combination of rigorous EAE animal studies, novel bioinformatic approaches, use of human cell lines, and implementation of well-powered, age- and sex-matched randomized controlled MS patient trials will be essential for improving MS patient outcomes and developing novel MS therapeutics to prevent and revert MS disease progression.

The modulatory effect of high salt on immune cells and related diseases

BACKGROUND

The adverse effect of excessive salt intake has been recognized in decades. Researchers have mainly focused on the association between salt intake and hypertension. However, studies in recent years have proposed the existence of extra-renal sodium storage and provided insight into the immunomodulatory function of sodium.

OBJECTIVES

In this review, we discuss the modulatory effects of high salt on various innate and adaptive immune cells and immune-regulated diseases.

METHODS

We identified papers through electronic searches of PubMed database from inception to March 2022.

RESULTS

An increasing body of evidence has demonstrated that high salt can modulate the differentiation, activation and function of multiple immune cells. Furthermore, a high-salt diet can increase tissue sodium concentrations and influence the immune responses in microenvironments, thereby affecting the development of immune-regulated diseases, including hypertension, multiple sclerosis, cancer and infections. These findings provide a novel mechanism for the pathology of certain diseases and indicate that salt might serve as a target or potential therapeutic agent in different disease contexts.

CONCLUSION

High salt has a profound impact on the differentiation, activation and function of multiple immune cells. Additionally, an HSD can modulate the development of various immune-regulated diseases.

Anesthetic management for Placenta Accreta

Дослідження виконані у 82 вагітних і породіль при кесаревому розтині з приводу передлежання плаценти з вростанням на 37–38 тижні. Органозберігаюча операція була виконана за такою методикою: лапаротомія за Джоель Кохен, донний кесарів розтин з залишенням плаценти, перев’язка трьох пар магістральних маткових судин і внутрішніх клубових артерій з обох сторін (поетапна деваскуляризація матки) з подальшим видаленням стінки матки (метропластика) при вростанні плаценти. Операції виконані в умовах спінальної анестезії (Сан) 0,5 % гіпербаричним розчином бупівакаїну. Інфузійна програма будувалася відповідно до рекомендацій з обмежувальної інфузії. Преінфузію проводили збалансованим кристалоїдом Реосорбілакт (10–15 мл/кг) з подальшим введенням на етапах операції збалансованого кристалоїду і компонентів крові за необхідності. Оцінювали гемодинаміку, КОР та електроліти крові. Оцінку крововтрати проводили гравіметричним способом. Дослідження показали, що Сан і Реосорбілакт у програмі малооб’ємної інфузійної терапії зберігають доставку кисню на фізіологічному рівні, стабілізують гемодинамічний профіль і КОР. При вростанні плаценти використання сучасних технологій в анестезіології реаніматології та акушерстві, з мультидисциплінарним підходом, дозволяють реалізувати органозберігаючу тактику у цієї категорії жінок

Year in Review 2020: Noteworthy Literature in Cardiothoracic Critical Care

This year will be forever marked by the drastic changes COVID-19 wrought on our personal and professional lives. New roles and challenges in critical care have forced us to be constantly nimble and flexible in how we approach medicine. The strain of these challenges is apparent throughout the health care community and our society as a whole. Despite this adversity, 2020 will also be remembered for fantastic advances in research. This article is a collection of influential and exciting studies published in 2020 encompassing a broad swath of critical care with a focus on cardiothoracic critical care. Themes include examinations of early extracorporeal membrane oxygenation support for out-of-hospital cardiac arrest patients, the impact of sedation and other risk factors on perioperative mortality, a novel fluid resuscitation strategy following cardiac surgery, and advances in the fields of heart and lung transplantation as well as how they were affected by COVID-19. Given that many cardiothoracic intensivists were redeployed to the care of SARS-CoV-2 patients, we also discuss important advances in therapeutics for the virus.

Crystalloid and Colloid Compositions and Their Impact

This manuscript will review crystalloid (hypo-, iso-, and hyper-tonic) and colloid (synthetic and natural) fluids that are available for intravenous administration with a focus on their electrolyte, acid-base, colligative, and rheological effects as they relate to each solution's efficacy and safety. The goal is for the reader to better understand the differences between each fluid and the influence on plasma composition, key organ systems, and their implications when used therapeutically in animals with critical illness.

Postoperative resuscitation with hypertonic saline or hyperoncotic albumin in patients following cardiac surgery: A review of the literature

BACKGROUND

Over-resuscitation in postcardiac surgery patients is associated with significant morbidity and mortality. Accordingly, there is a growing interest in hyperoncotic albumin and hypertonic saline for resuscitation in patients following cardiac surgery. In this article, we will review the use of hyperosmolar fluid therapies for resuscitation in postcardiac surgical patients from the current literature.

METHODS

A literature search was conducted in MEDLINE (PubMed) utilizing keywords, narrowing publications from 2009 to 2020.

RESULTS

Patients receiving concentrated albumin after cardiac surgery required less fluid bolus therapy, less time on vasopressors, and had a lower positive fluid balance compared with patients receiving crystalloids. There was no difference in mortality in those given 20% albumin compared with crystalloids postcardiac surgery. Patients administered hypertonic saline following cardiac surgery had increased urinary output but its effect on total fluid and body weight was not significantly different compared with crystalloids.

CONCLUSIONS

In this analysis, publications on resuscitation with hyperoncotic albumin and hypertonic saline in patients following cardiac surgery were reviewed. While there is data supporting the use of alternative fluid therapies in other critically ill populations, the limited literature focused on concentrated albumin and hypertonic saline for resuscitation following cardiac surgery is equivocal.

A Modern View of the Interstitial Space in Health and Disease

Increases in the volume of the interstitial space are readily recognized clinically as interstitial edema formation in the loose connective tissue of skin, mucosa, and lung. However, the contents and the hydrostatic pressure of this interstitial fluid can be very difficult to determine even in experimental settings. These difficulties have long obscured what we are beginning to appreciate is a dynamic milieu that is subject to both intrinsic and extrinsic regulation. This review examines current concepts regarding regulation of interstitial volume, pressure, and flow and utilizes that background to address three major topics of interest that impact IV fluid administration. The first of these started with the discovery that excess dietary salt can be stored non-osmotically in the interstitial space with minimal impact on vascular volume and pressures. This led to the hypothesis that, along with the kidney, the interstitial space plays an active role in the long-term regulation of blood pressure. Second, it now appears that hypovolemic shock leads to systemic inflammatory response syndrome principally through the entry of digestive enzymes into the intestinal interstitial space and the subsequent progression of enzymes and inflammatory agents through the mesenteric lymphatic system to the general circulation. Lastly, current evidence strongly supports the non-intuitive view that the primary factor leading to inflammatory edema formation is a decrease in interstitial hydrostatic pressure that dramatically increases microvascular filtration.

Hypertonic saline for fluid resuscitation in ICU patients post-cardiac surgery (HERACLES): a double-blind randomized controlled clinical trial

PURPOSE

Recent evidence questions a liberal approach to fluid resuscitation in intensive care unit (ICU) patients. Here, we assess whether use of hypertonic saline applied as single infusion at ICU admission after cardiac surgery can reduce cumulative perioperative fluid volume.

METHODS

Prospective randomized double-blind single-center clinical trial investigates effects of a single infusion of hypertonic saline (HS) versus normal saline (comparator). Primary endpoint was the cumulative amount of fluid administered in patients in the hypertonic saline versus the 0.9% saline groups (during ICU stay). Upon ICU admission, patients received a single infusion of 5 ml/kg body weight of 7.3% NaCl (or 0.9% NaCl) over 60 min. Patients undergoing cardiac surgery for elective valvular and/or coronary heart disease were included. Patients with advanced organ dysfunction, infection, and/or patients on chronic steroid medication were excluded.

RESULTS

A total of 101 patients were randomized to receive the study intervention (HS n = 53, NS n = 48). Cumulative fluid intake on the ICU (primary endpoint) did not differ between the HS and the NS groups [median 3193 ml (IQR 2052-4333 ml) vs. 3345 ml (IQR 2332-5043 ml)]. Postoperative urinary output until ICU discharge was increased in HS-treated patients [median 2250 ml (IQR 1640-2690 ml) vs. 1545 ml (IQR 1087-1976 ml)], and ICU fluid balance was lower in the HS group when compared to the NS group [296 ml (IQR - 441 to 1412 ml) vs. 1137 ml (IQR 322-2660 ml)].

CONCLUSION

In a monocentric prospective double-blind randomized clinical trial, we observed that hypertonic saline did not reduce the total fluid volume administered on the ICU in critically ill cardiac surgery patients. Hypertonic saline infusion was associated with timely increase in urinary output. Variations in electrolyte and acid-base homeostasis were transient, but substantial in all patients.

Pharmacotherapy of sodium disorders in neurocritical care

PURPOSE OF REVIEW

To describe the pathophysiology and pharmacotherapy of dysnatremia in neurocritical care patients.

RECENT FINDINGS

Sodium disorders may affect approximately half of the neurocritical care patients and are associated with worse neurological outcome and increased risk of death. Pharmacotherapy of sodium disorders in neurocritical care patients may be challenging and is guided by a careful investigation of water and sodium balance.

SUMMARY

In case of hyponatremia, because of excessive loss of sodium, fluid challenge with isotonic solution, associated with salt intake is the first-line therapy, completed with mineralocorticoids if needed. In case of hyponatremia because of SIADH, fluid restriction is the first-line therapy followed by urea if necessary. Hypernatremia should always be treated with hypotonic solutions according to the free water deficit, associated in case of DI with desmopressin. The correction speed should take into consideration the symptoms associated with dysnatremia and the rapidity of the onset.

Fluid resuscitation in trauma: what are the best strategies and fluids?

BACKGROUND

Traumatic injuries pose a global health problem and account for about 10% global burden of disease. Among injured patients, the major cause of potentially preventable death is uncontrolled post-traumatic hemorrhage.

MAIN BODY

This review discusses the role of prehospital trauma care in low-resource/remote settings, goals, principles and evolving strategies of fluid resuscitation, ideal resuscitation fluid, and post-resuscitation fluid management. Management of fluid resuscitation in few special groups is also discussed.

CONCLUSIONS

Prehospital trauma care systems reduce mortality in low-resource/remote settings. Delayed resuscitation seems a better option when transport time to definitive care is shorter whereas goal-directed resuscitation with low-volume crystalloid seems a better option if transport time is longer. Few general recommendations regarding the choice of fluid are provided. Adhering to evidence-based clinical practice guidelines and local modifications based on patient population, available resources, and expertise will improve patient outcomes.

The Medical Management of Cerebral Edema: Past, Present, and Future Therapies

Cerebral edema is commonly associated with cerebral pathology, and the clinical manifestation is largely related to the underlying lesioned tissue. Brain edema usually amplifies the dysfunction of the lesioned tissue and the burden of cerebral edema correlates with increased morbidity and mortality across diseases. Our modern-day approach to the medical management of cerebral edema has largely revolved around, an increasingly artificial distinction between cytotoxic and vasogenic cerebral edema. These nontargeted interventions such as hyperosmolar agents and sedation have been the mainstay in clinical practice and offer noneloquent solutions to a dire problem. Our current understanding of the underlying molecular mechanisms driving cerebral edema is becoming much more advanced, with differences being identified across diseases and populations. As our understanding of the underlying molecular mechanisms in neuronal injury continues to expand, so too is the list of targeted therapies in the pipeline. Here we present a brief review of the molecular mechanisms driving cerebral edema and a current overview of our understanding of the molecular targets being investigated.

Fluid Stewardship During Critical Illness: A Call to Action

Intravenous fluids (IVFs) are the most common drugs administered in the intensive care unit. Despite the ubiquitous use, IVFs are not benign and carry significant risks associated with under- or overadministration. Hypovolemia is associated with decreased organ perfusion, ischemia, and multi-organ failure. Hypervolemia and volume overload are associated with organ dysfunction, delayed liberation from mechanical ventilation, and increased mortality. Despite appropriate provision of IVF, adverse drug effects such as electrolyte abnormalities and acid-base disturbances may occur. The management of volume status in critically ill patients is both dynamic and tenuous, a process that requires frequent monitoring and high clinical acumen. Because patient-specific considerations for fluid therapy evolve across the continuum of critical illness, a standard approach to the assessment of fluid needs and prescription of IVF therapy is necessary. We propose the principle of "fluid stewardship," guided by 4 rights of medication safety: right patient, right drug, right route, and right dose. The successful implementation of fluid stewardship will aid pharmacists in making decisions regarding IVF therapy to optimize hemodynamic management and improve patient outcomes. Additionally, we highlight several areas of focus for future research, guided by the 4 rights construct of fluid stewardship.

Base excess is superior to lactate-levels in prediction of ICU mortality after cardiac surgery

Introduction

Cardiac surgery with the use of cardiopulmonary bypass is known to induce distinct metabolic changes. Respective changes in acid-base status including increased systemic lactate levels were previously related to clinical outcomes, but data remain controversial. Therefore, we aim to investigate the relevance of lactate and base excess (BE) levels on ICU-mortality in patients admitted to the ICU after cardiac surgery.

Materials and methods

Perioperative data of patients treated in a tertiary care academic center admitted to the ICU after on-pump surgery were analyzed in a retrospective fashion. Receiver operation characteristic (ROC) curves were constructed for admission lactate-levels and BE with calculation of optimal cut-off values to predict ICU mortality. Univariate followed by multivariate regression models were constructed to identify potential outcome-relevant indices.

Results

Data from 1,058 patients were included in the analysis. Area under the curves for prediction of ICU mortality were 0.79 for lactate levels at ICU admission (sensitivity 61.9%/ specificity 87.5%; optimal cut-off level 3.9mmol/l), and 0.7 for BE (sensitivity 52.4%/ specificity 93.8%, optimal cut-off level -6.7), respectively. Multivariate regression identified BE < -6.7 as the single metabolic predictor of ICU-mortality (HR 4.78, 95%-CI 1.4–16.33, p = 0.01). Explorative subgroup analyses revealed that the combination of lactate ≤3.9mmol/l and BE ≤ -6.7 has stronger impact on mortality than a combination of lactate of >3.9mmol/l and BE > -6.7 (HR 2.56, 95%-CI 0.18–37.17).

Conclusions

At ICU-admission, severely reduced BE appears superior to hyperlactatemia with regard to prediction of ICU-mortality in patients after cardiac surgery.

A dose-response relationship study of hypertonic saline on brain relaxation during supratentorial brain tumour craniotomy

Background: A prospective, randomized, double-blind study was designed to assess differences in brain relaxation between 2 doses of 3% HS during elective supratentorial brain tumour surgery.Methods: 60 patients undergoing supratentorial craniotomy for tumour resection were enrolled to receive either 3 mL/kg (group L) or 5 mL/kg (group H) of 3% HS administered at skin incision. Brain relaxation was assessed after dura opening on a scale ranging 1-4 (1 = perfectly relaxed, 2 = satisfactorily relaxed, 3 = firm brain, 4 = bulging brain). Hemodynamic variables and laboratory values (blood gases, osmolarity, haematocrit, and lactate) were collected before HS infusion and 30, 120 and 360 min after it. Presence of midline shift, postoperative complications, PCU and hospital stay, and mortality after 30 days were also recorded.Results: There was no difference in brain relaxation, with 2.0 (1.0-3.0) and 2.0 (1.0-2.3) (P = 0.535) for patients in groups L and H, respectively. If adjusted for the presence of midline shift, 50% of patients had adequate brain relaxation scores (grades 1 and 2) in group L and 61% in group H (OR 0.64, CI = 0.16-2.49, P = 0.515). No significant differences in perioperative outcome, mortality and length of PCU and hospital stay were observed.Conclusion: 3 mL/kg of 3% HS result in similar brain relaxation scores as 5 mL/kg in patients undergoing craniotomy for supratentorial brain tumour. This study reveals that both high and low doses of 3% HS may be less effective on intraoperative brain relaxation in patients with midline shift.