Impact of positive fluid balance on critically ill surgical patients: A prospective observational study

Capillary leak and endothelial permeability in critically ill patients: a current overview

Capillary leak syndrome (CLS) represents a phenotype of increased fluid extravasation, resulting in intravascular hypovolemia, extravascular edema formation and ultimately hypoperfusion. While endothelial permeability is an evolutionary preserved physiological process needed to sustain life, excessive fluid leak-often caused by systemic inflammation-can have detrimental effects on patients' outcomes. This article delves into the current understanding of CLS pathophysiology, diagnosis and potential treatments. Systemic inflammation leading to a compromise of endothelial cell interactions through various signaling cues (e.g., the angiopoietin-Tie2 pathway), and shedding of the glycocalyx collectively contribute to the manifestation of CLS. Capillary permeability subsequently leads to the seepage of protein-rich fluid into the interstitial space. Recent insights into the importance of the sub-glycocalyx space and preserving lymphatic flow are highlighted for an in-depth understanding. While no established diagnostic criteria exist and CLS is frequently diagnosed by clinical characteristics only, we highlight more objective serological and (non)-invasive measurements that hint towards a CLS phenotype. While currently available treatment options are limited, we further review understanding of fluid resuscitation and experimental approaches to target endothelial permeability. Despite the improved understanding of CLS pathophysiology, efforts are needed to develop uniform diagnostic criteria, associate clinical consequences to these criteria, and delineate treatment options.

A retrospective cohort study on the clinical outcomes of patients admitted to intensive care units with dysnatremia

With evolving patient characteristics and patterns of ICU utilization, the impact of dysnatremias on patient outcomes and healthcare costs in the present era have not been well studied. Patients ≥ 18 years admitted to the ICUs in public hospitals in Hong Kong between January 2010 and June 2022 and had at least one serum sodium measurement obtained within 24 h prior to or following ICU admission were stratified into normonatremic (135-145 mmol/L), hyponatremic (< 135 mmol/L) and hypernatremic (> 145 mmol/L) groups. A total of 162,026 patients were included-9098 (5.6%), 40,533 (25.0%) and 112,395 (69.4%) patients were hypernatremic, hyponatremic and normonatremic at the time of ICU admission, respectively. The odds of patients with hypernatremia and hyponatremia dying in the ICU were 27% and 14% higher (aOR 1.27, 95% CI 1.19-1.36 and aOR 1.14, 95% CI 1.08-1.19, respectively; P < 0.001 for both), and 52% and 21% higher for dying in the hospital (aOR 1.52, 95% CI 1.43-1.62 and aOR 1.21, 95% CI 1.17-1.26, respectively; P < 0.001 for both] compared with those with normonatremia. Patients with dysnatremia also had longer ICU length of stay (LOS), hospital LOS, and higher healthcare costs than the normonatremic group. Dysnatremias at ICU admission were associated with increased ICU and in-hospital mortality and overall healthcare burden.

Postoperative acute respiratory distress syndrome in randomized controlled trials

BACKGROUND

Acute respiratory distress syndrome is a potentially fatal postoperative complication. We aimed to estimate temporal trends of the representation of patients with postoperative acute respiratory distress syndrome in clinical trials, determine their distinct clinical features, and identify predictors of mortality.

METHODS

This is a secondary analysis of 7 randomized controlled clinical trials conducted by the Acute Respiratory Distress Syndrome Network and the Clinical Trials Network for the Prevention and Early Treatment of Acute Lung Injury. Patients with acute respiratory distress syndrome were classified into a postoperative acute respiratory distress syndrome group (ie, patients who had undergone elective surgery in the immediate period before trial enrollment) and a non-postoperative acute respiratory distress syndrome group.

RESULTS

Out of 5,316 patients with acute respiratory distress syndrome, 256 (4.8%) had postoperative acute respiratory distress syndrome. Representation of postoperative acute respiratory distress syndrome in trials gradually declined from 2000 to 2011, but it remained stable afterward at 2.7%. Postoperative acute respiratory distress syndrome was associated with lower 90-day mortality (24.6% vs 30.9%, P = .032) than non-postoperative acute respiratory distress syndrome, even after adjusting for age, acute respiratory distress syndrome severity, usage of vasopressors at baseline, and the study publication year (hazard ratio 0.63, 95% confidence interval 0.49-0.82). Age (odds ratio 1.07, 95% confidence interval 1.04-1.09), immunosuppression (odds ratio 4.12, 95% confidence interval 1.43-11.86), and positive fluid balance (odds ratio 1.09, 95% confidence interval 1.04-1.14) were associated with 90-day mortality among patients with postoperative acute respiratory distress syndrome.

CONCLUSION

Representation of postoperative acute respiratory distress syndrome in trials of the Acute Respiratory Distress Syndrome Network and the Clinical Trials Network for the Prevention and Early Treatment of Acute Lung Injury gradually declined from 2000 to 2011 but remained stable afterward. Postoperative acute respiratory distress syndrome was associated with lower mortality than non-postoperative acute respiratory distress syndrome. These findings may put both temporal trends and the prognosis of postoperative acute respiratory distress syndrome in perspective. Also, positive fluid balance was associated with the mortality of patients with postoperative acute respiratory distress syndrome.

Protocolised early de-resuscitation in septic shock (REDUCE): protocol for a randomised controlled multicentre feasibility trial

BACKGROUND

Fluid overload is associated with excess mortality in septic shock. Current approaches to reduce fluid overload include restrictive administration of fluid or active removal of accumulated fluid. However, evidence on active fluid removal is scarce. The aim of this study is to assess the efficacy and feasibility of an early de-resuscitation protocol in patients with septic shock.

METHODS

All patients admitted to the intensive care unit (ICU) with a septic shock are screened, and eligible patients will be randomised in a 1:1 ratio to intervention or standard of care.

INTERVENTION

Fluid management will be performed according to the REDUCE protocol, where resuscitation fluid will be restricted to patients showing signs of poor tissue perfusion. After the lactate has peaked, the patient is deemed stable and assessed for active de-resuscitation (signs of fluid overload). The primary objective of this study is the proportion of patients with a negative cumulative fluid balance at day 3 after ICU. Secondary objectives are cumulative fluid balances throughout the ICU stay, number of patients with fluid overload, feasibility and safety outcomes and patient-centred outcomes. The primary outcome will be assessed by a logistic regression model adjusting for the stratification variables (trial site and chronic renal failure) in the intention-to-treat population.

ETHICS AND DISSEMINATION

The study was approved by the respective ethical committees (No 2020-02197). The results of the REDUCE trial will be published in an international peer-reviewed medical journal regardless of the results.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov, NCT04931485.

A system theory based digital model for predicting the cumulative fluid balance course in intensive care patients

Background: Surgical interventions can cause severe fluid imbalances in patients undergoing cardiac surgery, affecting length of hospital stay and survival. Therefore, appropriate management of daily fluid goals is a key element of postoperative intensive care in these patients. Because fluid balance is influenced by a complex interplay of patient-, surgery- and intensive care unit (ICU)-specific factors, fluid prediction is difficult and often inaccurate. Methods: A novel system theory based digital model for cumulative fluid balance (CFB) prediction is presented using recorded patient fluid data as the sole parameter source by applying the concept of a transfer function. Using a retrospective dataset of n = 618 cardiac intensive care patients, patient-individual models were created and evaluated. RMSE analyses and error calculations were performed for reasonable combinations of model estimation periods and clinically relevant prediction horizons for CFB. Results: Our models have shown that a clinically relevant time horizon for CFB prediction with the combination of 48 h estimation time and 8-16 h prediction time achieves high accuracy. With an 8-h prediction time, nearly 50% of CFB predictions are within ±0.5 L, and 77% are still within the clinically acceptable range of ±1.0 L. Conclusion: Our study has provided a promising proof of principle and may form the basis for further efforts in the development of computational models for fluid prediction that do not require large datasets for training and validation, as is the case with machine learning or AI-based models. The adaptive transfer function approach allows estimation of CFB course on a dynamically changing patient fluid balance system by simulating the response to the current fluid management regime, providing a useful digital tool for clinicians in daily intensive care.

Prognostic value of phase angle and bioelectrical impedance vector in critically ill patients: A systematic review and meta-analysis of observational studies

BACKGROUND AND AIMS

Assessment of the raw parameters derived from bioelectrical impedance analysis (BIA) has gained emphasis in critically ill patients. The phase angle (PhA) reflects the integrity of the cell membrane, and bioelectrical impedance vector analysis (BIVA) is indicative of patients' hydration status. The aim of this study was to investigate whether these parameters are associated with clinical outcomes in the intensive care unit (ICU) setting.

METHODS

We conducted a systematic review with meta-analysis. We searched PubMed, Embase, Scopus and Web of Science for all published observational studies without language restrictions up to April 2022. Two reviewers independently performed study selection and data extraction. We judged the risk of bias by the Newcastle-Ottawa Scale and the certainty of evidence by the GRADE approach. Mortality was the primary outcome. Secondary outcomes included ICU length of stay, hospital length of stay, duration of mechanical ventilation, nutritional risk, and malnutrition. A meta-analysis with a random-effect model was performed to combine data on R version 3.6.2.

RESULTS

Twenty-seven studies were included in the systematic review (4872 participants). Pooled analysis revealed that patients with low PhA had a higher risk of death (14 studies; RR = 1.82, 95% CI 1.46 to 2.26; I² = 42%) and spent more days in ICU (6 studies; MD = 1.79, 95% CI 0.33 to 3.24, I² = 69%) in comparison to patients with normal PhA. The pooled analysis also showed higher PhA values in survivors compared to non-survivor patients (12 studies; MD = 0.75°, 95% CI 0.60° to 0.91°, I² = 31%). Overhydration defined by BIVA was not a predictor of mortality (4 studies; RR = 1.01, 95% CI 0.70 to 1.46; I² = 0%). More than 40% of primary studies were classified with a high risk of bias, and the quality of evidence ranged from low to very low.

CONCLUSIONS

This meta-analysis revealed, with limited evidence, that low PhA was associated with higher mortality and ICU length of stay, while overhydration identified by BIVA was not a predictor of death in critically ill patients.

Association between fluid intake and extubation failure in intensive care unit patients with negative fluid balance: a retrospective observational study

BACKGROUND

Negative fluid balance (NFB) is associated with reduced extubation failure. However, whether achieving more NFB can further improve extubation outcome has not been investigated. This study aimed to investigate whether more NFB and restricted fluid intake were associated with extubation success.

METHODS

We performed a retrospective study of adult patients with mechanical ventilation (MV) admitted to Medical Information Mart for Intensive Care (MIMIC-III) from 2001 to 2012. Patients with duration of MV over 24 hours and NFB within 24 hours before extubation were included for analysis. The primary outcome was extubation failure, defined as reintubation within 72 hours after extubation. Association between fluid balance or fluid intake and extubation outcome were investigated with multivariable logistic models.

RESULTS

A total of 3433 extubation events were recorded. 1803 with NFB were included for the final analysis, of which 201(11.1%) were extubation failure. Compared with slight NFB (- 20 to 0 ml/kg), more NFB were not associated improved extubation outcome. Compared with moderate fluid intake (30 to 60 ml/kg), lower (< 30 ml/kg, OR 0.75, 95% CI [0.54, 1.05], p = 0.088) or higher (> 60 ml/kg, OR 1.63, 95% CI [0.73, 3.35], p = 0.206) fluid intake was not associated with extubation outcome. Duration of MV, chronic obstructive pulmonary disease (COPD), hypercapnia, use of diuretics, and SAPSIIscore were associated with extubation failure.

CONCLUSIONS

More NFB or restricted fluid intake were not associated with reduced extubation failure in patients with NFB. However, for COPD patients, restricted fluid intake was associated with extubation success.

Evaluating the Impact of Positive Fluid Balance on Mortality and Length of Stay in Septic Shock Patients

Background

Sepsis is accountable for major morbidity and mortality in patients with critical illnesses. The present research was undertaken to evaluate the correlation between fluid balance during hospitalizations and patient outcomes in patients with sepsis.

Methods

An observational study was undertaken at the Critical Care Department, Shifa International Hospital, Islamabad, Pakistan between December 2021 to April 2022. The patients included were over the age of 17 years, with a proven diagnosis of infection. These patients either had positive bacterial cultures, suffered from organ failure secondary to sepsis, or had clinically evident signs of infection. Patients who were discharged during the period of study were eliminated from the study population. All patients were informed of the process and signed consent was obtained. Basic demographic information was recorded, which included the existence of any comorbid conditions, organ failure, medication use, or infection history. The severity of critical illness was determined for every single patient along with organ damage. The final patient outcome was recorded as in-hospital mortality.

Results

A total of 307 patients were included in the study with a total of 165 (53.75%) male patients. The overall mortality rate was 39.74%. The mean length of hospitalization was 17.42 ± 8.3 days. A high SOFA score was significantly associated with quartile 4 with a mean score of 14.1 (p < 0.001). Similarly, a significantly higher APACHE score was found in patients in quartile 4 (p < 0.001) thus indicating a relationship between severity of illness and positive fluid balance. Upon further assessment, it was found that the 28th day and 90th day were significantly greater in quartile 4 in comparison to other quartiles. Similarly, the overall length of stays in the hospital and in the ICU were also significantly associated with greater fluid balance (p < 0.001). 

Conclusion

In our study, it was concluded that monitoring fluid balance in critically ill patients is very important. The highest 28-day and 90-day mortality were seen in patients with the greatest positive fluid balance. However, the cause of high mortality in this cohort could be multifactorial; therefore, the relationship of positive fluid balance with patient outcome remains debatable.

Acute intensive care unit resuscitation of severely injured trauma patients: Do we need a new strategy?

BACKGROUND

Unlike recent advances in blood product resuscitation, intravenous crystalloid (IVF) use after intensive care unit (ICU) admission in hemorrhagic shock has received less attention and current recommendations are based on limited evidence. To address this knowledge gap, we aimed to determine associations between IVF administration during acute ICU resuscitation and outcomes. We hypothesized that larger IVF volumes are associated with worse outcomes.

METHODS

We linked our trauma registry with electronic health record data (2012-2015) to identify adults with an initial lactate level of ≥4 mmol/L and documented lactate normalization (≤2 mmol/L), excluding those with isolated head Abbreviated Injury Scale score ≥3. We focused on the period from ICU admission to lactate normalization, analyzing duration, volume of IVF, and proportion of volume as 1-L boluses. We used linear regression to determine associations with ICU length of stay and duration of mechanical ventilation in survivors, and logistic regression to identify associations with acute kidney injury and home discharge while adjusting for important covariates.

RESULTS

We included 337 subjects. Median time to lactate normalization was 15 hours (interquartile range, 7-25 hours), and median IVF volume was 3.7 L (interquartile range, 1.5-6.4 L). The fourfold difference between the upper and lower quartiles of both duration and volume remained after stratifying by injury severity. Hourly volumes tapered over time but persistently aggregated at 0.5 and 1 L, with 167 subjects receiving at least one 0.5-L bolus for 6 hours after ICU admission. Administration of larger volumes was associated with longer ICU length of stay and duration of mechanical ventilation, as well as acute kidney injury.

CONCLUSION

There is substantial variation in volume administered during acute ICU resuscitation, both absolutely and temporally, despite accounting for injury severity. Administration of larger volumes during acute ICU resuscitation is associated with worse outcomes. There is an opportunity to improve outcomes by further investigating and standardizing this important phase of care.

LEVEL OF EVIDENCE

Therapeutic/care management, level IV.

Risk Factors Associated With Early Postoperative Respiratory Failure: A Matched Case-Control Study

BACKGROUND

Postoperative respiratory failure is the most common serious postoperative pulmonary complication, yet little is known about factors that can reduce its incidence. We sought to elucidate modifiable factors associated with respiratory failure that developed within the first 5 d after an elective operation.

MATERIALS AND METHODS

Matched case-control study of adults who had an operation at five academic medical centers between October 1, 2012 and September 30, 2015. Cases were identified using administrative data and confirmed via chart review by critical care clinicians. Controls were matched 1:1 to cases based on hospital, age, and surgical procedure.

RESULTS

Our total sample (n = 638) was 56.4% female, 71.3% white, and had a median age of 62 y (interquartile range 51, 70). Factors associated with early postoperative respiratory failure included male gender (odds ratio [OR] 1.72, 95% confidence interval [CI] 1.12-2.63), American Society of Anesthesiologists class III or greater (OR 2.85, 95% CI 1.74-4.66), greater number of preexisting comorbidities (OR 1.14, 95% CI 1.004-1.30), increased operative duration (OR 1.14, 95% CI 1.06-1.22), increased intraoperative positive end-expiratory pressure (OR 1.23, 95% CI 1.13-1.35) and tidal volume (OR 1.13, 95% CI 1.004-1.27), and greater net fluid balance at 24 h (OR 1.17, 95% CI 1.07-1.28).

CONCLUSIONS

We found greater intraoperative ventilator volume and pressure and 24-h fluid balance to be potentially modifiable factors associated with developing early postoperative respiratory failure. Further studies are warranted to independently verify these risk factors, explore their role in development of early postoperative respiratory failure, and potentially evaluate targeted interventions.

Intraoperative lung protective ventilation in peritonitis patients undergoing emergency laparotomy: A randomised controlled trial

Background and Aims:

Lung protective ventilation (LPV) is recommended in acute respiratory distress syndrome. However, role of intraoperative LPV in elective laparotomy is controversial and it has not been evaluated in emergency laparotomy (EL). The aim of the study was to identify whether use of intraoperative LPV in EL in peritonitis patients reduces postoperative pulmonary complications (POPC).

Methods:

After institutional ethics committee approval and informed written consent, 98 adult patients undergoing EL for peritonitis were randomised into two groups. Patients in group 1 received LPV (tidal volume 6–8 ml/kg, positive end expiratory pressure (PEEP) 6–8 cm H₂O and recruitment manoeuvre every 30 min) and patients in group 2 received conventional ventilation (tidal volume 10-12 ml/kg, without PEEP/recruitment). Primary outcome was incidence of POPC on day 7.

Results:

Data of 94 patients (n = 45 in group 1 & n = 49 in group 2) were available. Baseline demographic & laboratory parameters were comparable. Incidence of POPC was similar in both the groups [42.9% in group 1 vs. 53.3% in group 2; risk difference -10.4% (-30.6%, 9.6%); P = 0.31]. Mortality during hospital stay was 26.7% patients in group 1 and 26.5% patients in group 2 [risk difference (95% CI) 0.14%, (-17.7, 18.0); P = 0.98]. Length of hospital stay [median interquartile range (IQR) 13 (9–18) days in group 1 vs. 13 (8–21) days in group 2; P = 0.82] and length of intensive care unit stay [median (IQR) 7 (4–10) days vs. 6 (3–12) days; P = 0.88] were also similar in both groups.

Conclusion:

LPV during EL in peritonitis patients does not reduce the incidence of POPC compared to conventional ventilation.

Early positive fluid balance is predictive for venous thromboembolism in critically ill surgical patients

BACKGROUND

Positive fluid balance (FB) in the intensive care unit (ICU) may be a marker for increased venous thromboembolism (VTE) risk. We hypothesized that an early positive fluid balance (FB) would be associated with increased VTE occurrence.

METHODS

A single-center retrospective review of surgical ICU patients was conducted from May 2011 to December 2014. Patients with a VTE were compared to those who did not develop a VTE (NVTE).

RESULTS

There were 619 patients analyzed with 77 (12.4%) diagnosed with a VTE; these patients had longer ventilator days (12.3 vs. 5.0 days, p < 0.01) and ICU stays (10.3 vs. 6.4 days, p < 0.01), and were more likely to have a net FB ≥ 4L over the first three days (62% vs. 44%, p < 0.01). A FB ≥ 4L over the first three ICU days was an independent predictor of VTE (AOR 1.74, p = 0.04).

CONCLUSION

Patients with an early positive FB are more likely to develop a VTE.

Association between postoperative fluid balance and mortality and morbidity in critically ill patients with complicated intra-abdominal infections: a retrospective study

Background

Postoperative fluid overload may increase the risk of developing pulmonary complications and other adverse outcomes. We evaluated the impact of excessive fluid administration on postoperative outcomes in critically ill patients.

Methods

We reviewed the medical records of 320 patients admitted to intensive care unit (ICU) after emergency abdominal surgery for complicated intra-abdominal infection (cIAI) between January 2013 and December 2018. The fluid balance data of the patients were reviewed for a maximum of 7 days. The patients were grouped based on average daily fluid balance with a cutoff value of 20 ml/kg/day. Propensity score matching was performed to reduce the underlying differences between the groups.

Results

Patients with an average daily fluid balance of ≥20 ml/kg/day were associated with higher rates of 30-day mortality (11.8% vs. 2.4%; P=0.036) than those with lower fluid balance (<20 ml/kg/day). Kaplan-Meier survival curves for 30-day mortality in these groups also showed a better survival rate in the lower fluid balance group with a statistical significance (P=0.020). The percentage of patients who developed pulmonary consolidation during ICU stay (47.1% vs. 24.7%; P=0.004) was higher in the fluid-overloaded group. Percentages of newly developed pleural effusion (61.2% vs. 57.7%; P=0.755), reintubation (18.8% vs. 10.6%; P=0.194), and infectious complications (55.3% vs. 49.4%; P=0.539) showed no significant differences between the two groups.

Conclusions

Postoperative fluid overload in patients who underwent emergency surgery for cIAI was associated with higher 30-day mortality and more frequent occurrence of pulmonary consolidation. Postoperative fluid balance should be adjusted carefully to avoid adverse clinical outcomes.

Approach to the liver transplant early postoperative period: an institutional standpoint

The liver transplant program in our center started in 1992, and post-liver transplant patients are still admitted to the intensive care unit. For the intensive care physician, a learning curve started then, skills were acquired, and a specific practice was established. Throughout this time, several concepts changed, improving the care of these patients. The practical approach varies between liver transplant centers, according to local specificities. Hence, we wanted to present our routine practice to stimulate the debate between dedicated teams, which can allow the introduction of new ideas and potentially improve each local standard of care.

Perioperative Fluid Restriction in Abdominal Surgery: A Systematic Review and Meta-analysis

BACKGROUND

Perioperative fluid management is a critical component in patients undergoing abdominal surgery. However, the benefit of restricted fluid regimen remains inconclusive. This systematic review aimed to explore potential factors causing these inconsistent findings.

METHODS

The literature searches were performed in three databases including PubMed, Embase, and the Cochrane library until August 30, 2018. Only randomized, controlled trials comparing the effect of restricted versus liberal regimen in abdominal surgery were included. The primary outcome was total postoperative complications. Subgroup analysis was performed according to between-group weight increase difference (≥ 2 kg and < 2 kg) and fluid intake ratio (≥ 1.8 and < 1.8).

RESULTS

Sixteen studies were finally included in this meta-analysis. The benefit of the restricted regimen in reducing postoperative complication was only significant in the subgroup with high weight increase difference (≥ 2 kg) (RR 0.67, 95% CI 0.57-0.79) and the subgroup with high fluid intake ratio (≥ 1.8) (RR 0.72, 95% CI 0.62-0.82). In the subgroup with low weight increase difference (< 2 kg) or low fluid intake ratio (< 1.8), the effect of the restricted regimen was not significant (RR 0.88, 95% CI 0.51-1.50, and RR 1.18, 95% CI 0.91-1.53, respectively).

CONCLUSIONS

The benefit of the restricted regimen was only significant in the subgroup with high weight increase difference (≥ 2 kg) or high fluid intake ratio (≥ 1.8).

A Preliminary Investigation into the Association of Chloride Concentration on Morbidity and Mortality in Hospitalized Canine Patients

Purpose

To evaluate whole blood chloride concentration and hospital-acquired AKI in hospitalized canine patients. Secondary outcome measures included the volume-adjusted chloride load, in-hospital mortality and length of ICU stay.

Patients and Methods

This is a prospective, observational study. Sixty dogs admitted to the ICU and receiving IV fluid therapy for >24 hours from February 2018 to July 2019. Corrected chloride and creatinine concentrations were obtained twice daily. Total volume of IV fluid and total chloride load were recorded. Volume-adjusted chloride load (VACL) was calculated by dividing the chloride administered by the volume of fluid administered. Hospital-acquired AKI was defined as an increase in creatinine of ≥26.5 μmol/L (0.3 mg/dL) or 150% from baseline to maximum. Survival to hospital discharge or non-survival and ICU length of stay were also recorded.

Results

Fifteen out of 60 patients developed hospital-acquired AKI. Maximum corrected chloride was significantly different in AKI group (median 122.3 mmol/L) vs non-AKI group (median 118.1 mmol/L; p=0.0002). Six out of 60 patients developed hyperchloremia. Hyperchloremic patients were significantly more likely to develop in-hospital AKI (p=0.03). Patients hospitalized ≥2 days had a significantly higher [Cl⁻]_max compared to those with shorter ICU stay (121.8 ± 5.9 mmol/L vs 117.5 ± 4.3 mmol/L; p=0.002). Eight out of 60 patients were non-survivors. Maximum corrected chloride and creatinine concentrations were not significantly different between survivors and non-survivors. VACL was not significantly different between AKI or mortality groups.

Conclusion

Maximum corrected chloride concentration was significantly higher in dogs with hospital-acquired AKI, even amongst dogs without hyperchloremia. Additionally, maximum corrected chloride concentrations were significantly higher in dogs hospitalized in the ICU longer compared to those hospitalized for fewer than two days. There was no significant difference in VACL in any of the outcome groups. Results from this study suggest alterations in chloride may be observed alongside the development of acute kidney injuries. Future studies in critically ill dogs are warranted.

Fluid Overload and Risk of Mortality in Critically Ill Patients

BACKGROUND

Fluid overload (FO) is a condition present in critical care units, and it is associated with clinical complications and worse outcomes for severe patients.

OBJECTIVE

The aim of this study was to verify if FO is a risk factor for mortality in critically ill patients.

METHODS

Retrospective study performed in a Brazilian intensive care unit, from January to March 2016, with patients older than 18 years and hospitalized for more than 24 hours. Demographic and clinical data, as well as fluid balance and overload, were analyzed to verify the risk factors for mortality. A logistic regression model was elaborated, and significance was set at P < .05.

RESULTS

There were 158 patients included, of which only 13 (8.2%) presented FO. Mortality was verified in individuals 30 (18.9%), of whom only 7 (23.3%) developed FO, which was lower in survivors 6 (4.9%), P = .001. In the simple regression model, the FO was significant (odds ratio [OR], 6.23; 95% confidence interval [CI], 2.04-19.53), P = .001. However, in the multiple regression model, there were significant findings only for mechanical ventilation (OR, 5.86; 95% CI, 2.10-18.12, P = .001), acute kidney injury (OR, 4.05; 95% CI, 1.53-11; P = .001), and noradrenaline (OR, 3.85; 95% CI, 1.01-9.51; P = .041); FO was not significant (OR, 3.68; 95% CI, 0.91-15.55; P = .069).

CONCLUSION

Fluid overload is higher in patients who died. Therefore, it was not considered a risk factor for mortality.

Fluid overload after coronary artery bypass graft in patients on maintenance hemodialysis is associated with prolonged time on mechanical ventilation

Background

Fluid overload is a risk factor for morbidity, mortality, and prolonged ventilation time after surgery. Patients on maintenance hemodialysis might be at higher risk. We hypothesized that fluid accumulation would be directly associated with extended ventilation time in patients on hemodialysis, as compared to patients with chronic kidney disease not on dialysis (CKD3–4) and patients with normal renal function (reference group).

Methods

This is a prospective observational study that included patients submitted to isolated and elective coronary artery bypass surgery, divided in 3 groups according to time on mechanical ventilation: < 24 h, 24-48 h and > 48 h. The same observer followed patients daily from the surgery to the hospital discharge. Cumulative fluid balance was defined as the sum of daily fluid balance over the first 5 days following surgery.

Results

Patients requiring more than 48 h of ventilation (5.3%) had a lower estimated glomerular filtration rate, were more likely to be on maintenance dialysis, had longer anesthesia time, needed higher dobutamine and noradrenaline infusion following surgery, and had longer hospitalization stay. Multivariate analysis revealed that the fluid accumulation, scores of sequential organ failure assessment in the day following surgery, and the renal function (normal, chronic kidney disease not on dialysis and maintenance hemodialysis) were independently associated with time in mechanical ventilation. Among patients on hemodialysis, the time from the surgery to the first hemodialysis session also accounted for the time on mechanical ventilation.

Conclusions

Fluid accumulation is an important risk factor for lengthening mechanical ventilation, particularly in patients on hemodialysis. Future studies are warranted to address the ideal timing for initiating dialysis in this scenario in an attempt to reduce fluid accumulation and avoid prolonged ventilation time and hospital stay.

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.

The Effect of Adding Dopamine Infusion to Noradrenaline Infusion Combined With Restrictive Hydration on Renal Function and Tissue Perfusion during Open Abdominal Surgeries

Objectives

This study was designed to assess the effect of adding dopamine infusion in addition to restrictive hydration combined with noradrenaline infusion on intraoperative renal function and serum lactate levels in comparison to restrictive hydration combined with noradrenaline infusion only and standard hydration during open abdominal surgeries.

Patients and Methods

One hundred and twenty patients were randomly assigned into three equal groups undergoing major open abdominal procedures. In Group I, dopamine infusion in addition to norepinephrine infusion were administered with restrictive hydration. In Group II, norepinephrine infusion was started before the induction of anesthesia with restrictive hydration. In Groups I and II, Ringer's solution was infused at a fixed rate of 2 mL.kg^-1.h^-1 until the end of surgery. In Group III, the conventional fluid replacement was introduced according maintenance, fluid deficit and third space loss. The outcome to be assessed was serial measurements of creatinine and serum lactate levels preoperatively, intraoperatively, and just postoperatively in addition to after 24 h.

Results

Serum lactate level was significantly low in Groups I and II than that in Group III intraoperatively and postoperatively. In addition, urine output was significantly more in Group I and Group III than in Group II. Creatinine level was higher with significance in Group II than in Group I and III 24 h postoperatively.

Conclusion

Dopamine infusion, when added to norepinephrine infusion combined with restricted hydration, improved urine output and creatinine level. Tissue perfusion as indicated by serum lactate level was more adequate in Groups I and II than that in Group III.

Calculated plasma volume status and outcomes in patients undergoing coronary bypass graft surgery

OBJECTIVES

Congestion is associated with worse outcomes in critically ill surgical patients but can be difficult to quantify noninvasively. We hypothesised that plasma volume status (PVS), estimated preoperatively using a validated formula that enumerates percentage change from ideal plasma volume (PV), would provide incremental prognostic utility after coronary artery bypass graft (CABG) surgery.

METHODS

In this retrospective cohort study, patients who underwent CABG surgery (1999-2010) were identified from a prospectively collected database. Actual ([1-haematocrit] x [a+(b x weight [kg])]) and ideal (c x weight [kg]) PV were obtained from equations where a, b and c are sex-dependent constants. Calculated PVS was then derived (100% x [(actual-ideal)/ideal]).

RESULTS

In 1887 patients (mean age 67±10 years; 79% male; median European System for Cardiac Operative Risk Evaluation [EuroSCORE] 4), mean PVS was -8.2±9%. While 8% of subjects had clinical evidence of congestion, a relatively increased PV (PVS >0%) was estimated in 17% and correlated with lower serum sodium, higher EuroSCORE and a diagnosis of diabetes mellitus. A PVS≥5.6% was optimally prognostic and associated with greater mortality (HR: 2.31, p=0.009), independently of, and incremental to, EuroSCORE, New York Heart Association class and serum sodium. A PVS≥5.6% also independently predicted longer intensive care (β: 0.65, p=0.007) and hospital (β: 2.01, p=0.006) stays, and greater postoperative renal (OR: 1.61, p=0.008) and arrhythmic (OR: 1.29, p=0.03) complications.

CONCLUSIONS

Higher PVS values, calculated simply from weight and haematocrit, are associated with worse inpatient outcomes after CABG. PVS could help refine risk stratification and further investigations are warranted to evaluate the potential clinical utility of PVS-guided management in patients undergoing CABG.

The Effect of Simultaneous Renal Replacement Therapy on Extracorporeal Membrane Oxygenation Support for Postcardiotomy Patients with Cardiogenic Shock: A Pilot Randomized Controlled Trial

OBJECTIVE

The objectives of this study were to determine the feasibility and safety of simultaneous renal replacement therapy (RRT) during extracorporeal membrane oxygenation (ECMO) support for postcardiotomy patients with cardiogenic shock and whether simultaneous RRT with ECMO would improve survival and reduce morbidity. The authors hypothesized that simultaneous RRT could facilitate effective fluid management and rapid metabolic control in postcardiotomy patients with cardiogenic shock who were undergoing ECMO support.

DESIGN

A parallel, open-label, single-center pilot randomized trial.

SETTING

University-affiliated cardiac surgery intensive care unit.

PARTICIPANTS

The study comprised 41 postcardiotomy patients with cardiogenic shock who received ECMO support.

INTERVENTIONS

Participants were enrolled and randomly assigned via a 1:1 allocation to a simultaneous RRT arm versus a standard care arm. The patients in the simultaneous RRT arm received RRT within 12 hours of the start of ECMO regardless of the conventional RRT indication. Simultaneous RRT was delivered with the RRT machine connected to the ECMO circuit. The patients in the standard care arm did not receive RRT at the start of ECMO unless the conventional RRT indications were fulfilled.

MEASUREMENTS AND MAIN RESULTS

All 41 patients enrolled were followed-up for 30 days and the results analyzed. The primary feasibility outcome was the time from randomization to simultaneous RRT of <12 hours in the simultaneous RRT arm. All participants in simultaneous RRT arm fulfilled with a median time from randomization to simultaneous RRT of 4.4 (2.7-5.6) hours. The 30-day all-cause mortality was 61.9% in the simultaneous RRT arm and 75.0% in the standard care arm (p = 0.51). The lactate clearance was higher in the simultaneous RRT arm (0.56 ± 0.4 v 0.28 ± 0.4 mmol/L/h; p = 0.04). There was lower cumulative fluid balance in the simultaneous RRT arm on ECMO day 3 (-1,510 [-3560 to 1,162] v -332 [-2,027 to 2,181]; p = 0.38) and ECMO day 5 (-2,671 [-5,197 to 3,334] v -1,509 [-3,595 to 1,162]; p = 0.41) without significance. There were no significant differences in adverse events reported and no hemodynamic instability owing to simultaneous RRT delivery.

CONCLUSIONS

This pilot study suggests the feasibility and safety of simultaneous RRT during ECMO support for postcardiotomy patients with cardiogenic shock, providing an efficient means for controlling fluid status and metabolics. A large trial based on this pilot study is required to confirm the clinical benefits.

Long-term Impact of Crystalloid versus Colloid Solutions on Renal Function and Disability-free Survival after Major Abdominal Surgery

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

The authors recently demonstrated that administration of balanced hydroxyethyl starch solution as part of intraoperative goal-directed fluid therapy was associated with better short-term outcomes than administration of a balanced crystalloid solution in patients having major open abdominal surgery. In the present study, a 1-yr follow-up of renal and disability outcomes in these patients was performed.

Methods

All patients enrolled in the earlier study were followed up 1 yr after surgery for renal function and disability using the World Health Organization Disability Assessment Schedule 2.0 (WHODAS). The main outcome measure was the estimated glomerular filtration rate. Other outcomes were serum creatinine, urea, pruritus, and WHODAS score. Groups were compared on a complete-case analysis basis, and modern imputation methods were then used in mixed-model regressions to assess the stability of the findings taking into account the missing data.

Results

Of the 160 patients enrolled in the original study, follow-up data were obtained for renal function in 129 and for WHODAS score in 114. There were no statistically significant differences in estimated glomerular filtration rate at 1 yr (ml min−1 1.73 m−2): 80 [65 to 92] for crystalloids versus 74 [64 to 94] for colloids; 95% CI [−10 to 7], P = 0.624. However, the WHODAS score (%) was statistically significantly lower in the colloid than in the crystalloid group (2.7 [0 to 12] vs. 7.6 [1.3 to 18]; P = 0.015), and disability-free survival was higher (79% vs. 60%; 95% CI [2 to 39]; P = 0.024).

Conclusions

In patients undergoing major open abdominal surgery, there was no evidence of a statistically significant difference in long-term renal function between a balanced hydroxyethyl starch and a balanced crystalloid solution used as part of intraoperative goal-directed fluid therapy, although there was only limited power to rule out a clinically significant difference. However, disability-free survival was significantly higher in the colloid than in the crystalloid group.

Outcomes After Massive Transfusion in Trauma Patients: Variability Among Trauma Centers

BACKGROUND

Exsanguinating trauma patients often require massive blood transfusion (defined as transfusion of 10 or more pRBC units within first 24 h). The aim of our study is to assess the outcomes of trauma patients receiving massive transfusion at different levels of trauma centers.

METHODS

Two-y (2013-2014) retrospective analysis of the American College of Surgeons Trauma Quality Improvement Program. We included all adult trauma patients who received massive transfusion (MT) of blood. Outcome measures were mortality, hospital length of stay, intensive care unit-free and ventilator-free days, blood products received, and complications.

RESULTS

We analyzed a total of 416,957 patients, of which 2776 met the inclusion criteria and included in the study. Mean age was 40.6 ± 20 y, 78.3% were males and 33.1% of the injuries were penetrating. Median injury severity score [IQR] was 29 [18-40], median [IQR] Glasgow Coma Scale 10[4-15]. Mean packed red blood cells transfusion in the first 24 h was 20 ± 13 units and mean plasma transfusion was 13 ± 11 units. Overall in-hospital mortality was 43.5%. Receiving MT in level I trauma center was independently associated with lower rates of mortality (odds ratio [OR]: 0.75 [0.46-0.96], P < 0.001). Higher injury severity score (OR: 1.020 [1.010-1.030], P < 0.001) and increased units of packed red blood cells transfused (OR: 1.067 [1.041-1.093], P < 0.001) were independently associated with increased mortality. However, there was no association between teaching status, age, gender, emergency department vitals, and units of plasma transfused.

CONCLUSIONS

Hemorrhage continues to remain one of the most common cause of death after trauma. Almost half of the patients who received massive transfusion died. Patients who receive massive blood transfusion in a level I trauma centers have improved survival compared with level II trauma centers.

Fluid volume, fluid balance and patient outcome in severe sepsis and septic shock: A systematic review

PURPOSE

This systematic review and meta-analysis was conducted to evaluate the mortality risk in severe sepsis and septic shock with a low and high fluid volume/balance.

METHODS

Cohort studies that compared the mortality of patients with low or high fluid volume/balance were included. Electronic databases: PubMed/Medline PLUS, Embase, Scopus, and Web of Science were searched. Patient mortality at the longest follow-up was the primary outcome measure. The data were analyzed using STATA 14 statistical software.

RESULTS

The current study included fifteen studies with 31,443 severe sepsis and/or septic shock patients. Patients with a high fluid balance have a 70% increased risk of mortality (pooled RR: 1.70; CI: 1.20, 2.41; P = .003). Survivors of severe sepsis and/or septic shock received higher fluid volume in the first three hours. However, fluid volume administered in the first 24 h was higher for non-survivors. Low volume resuscitation in the first 24 h had a significant mortality reduction (P = .02).

CONCLUSION

High fluid balance from the first 24 h to ICU discharge increases the risk of mortality in severe sepsis and/or septic shock. However, randomized clinical trials should be conducted to resolve the dilemma of fluid resuscitation.

Mortality in adult patients with fluid overload evaluated by BIVA upon admission to the emergency department

PURPOSE OF THE STUDY

The aim of this study was to investigate the association of fluid overload, measured by bioelectrical impedance vector analysis (BIVA) and also by accumulated fluid balance, with 30-day mortality rates in patients admitted to the emergency department (ED).

DESIGN

We conducted a prospective observational study of fluid overload using BIVA, taking measures using a multiple-frequency whole-body tetrapolar equipment. Accumulated fluid balances were obtained at 24, 48 and 72 hours from ED admission and its association with 30-day mortality.

PATIENTS

109 patients admitted to the ED classified as fluid overloaded by both methods.

RESULTS

According to BIVA, 71.6% (n=78) of patients had fluid overload on ED admission. These patients were older and had higher Sequential Organ Failure Assessment scores. During a median follow-up period of 30 days, 32.1% (n=25) of patients with fluid overload evaluated by BIVA died versus none with normovolaemia (p=0.001). There was no statistically significant difference in mortality between patients with and without fluid overload as assessed by accumulated fluid balance (p=0.81).

CONCLUSIONS

Fluid overload on admission evaluated by BIVA was significantly related to mortality in patients admitted to the ED.

Early negative fluid balance is associated with lower mortality after cardiovascular surgery

BACKGROUND

Early fluid expansion could prevent postoperative organ hypoperfusion. However, excessive fluid resuscitation adversely influences multiple organ systems. This retrospective, observational study aimed to investigate the relationship between early negative fluid balance and postoperative mortality in critically ill adult patients following cardiovascular surgery.

METHODS

In total, 567 critically ill patients who had undergone cardiovascular surgery and whose intensive care unit length of stay (LOS) was more than 24 hours were enrolled. The baseline characteristics, daily fluid balance and cumulative fluid balance were obtained. Patients were followed until discharge or day 28. Multivariate logistic regressions adjusted by propensity score were used to analyze the relationship between early negative fluid balance and postoperative mortality.

RESULTS

Overall, postoperative mortality was 6.2% (35/567). Acute Physiology and Chronic Health Evaluation II on admission (odd ratios [OR] 1.110), acute kidney injury stage (OR 1.639) and renal replacement therapy received (OR 3.922) were the independent risk factors of postoperative mortality, whereas negative daily fluid balance at day 2 (OR 0.411) was the protective factor. Patients with a negative daily fluid balance at day 2 had lower postoperative mortality (3.4% vs. 12.2% in the positive fluid balance group), lower acute kidney injury (AKI) stage, were less likely to receive renal replacement therapy (RRT) and experienced shorter hospital LOS compared with those with a daily positive fluid balance.

CONCLUSION

This retrospective, observational study indicates that early negative fluid balance is associated with lower postoperative mortality in critically ill patients following cardiovascular surgery. Further prospective, randomized trials are needed to prove the benefits from the restrictive fluid management strategy.

Patterns of vasopressor utilization during the resuscitation of massively transfused trauma patients

BACKGROUND

The use of vasopressors (VP) in the resuscitation of massively transfused trauma patients might be considered a marker of inadequate resuscitation. We sought to characterize the utilization of VP in patients receiving massive transfusion and examine the association of their use with mortality.

METHODS

Trauma patients admitted from January 2011 to October 2016 receiving massive transfusion, defined as 3 units of pRBC within the first hour from admission, were selected for analysis. Demographics, admission vital signs and labs, use of VP, surgical interventions and outcomes were collected. Standard statistical tools were utilized.

RESULTS

Over the 5-year study period, 120 trauma patients met inclusion criteria. The median age was 39 years with 77% being male and 41% sustaining a penetrating injury. Patients who received VP [VP (+)] were more likely to have a lower admission GCS (median 4.5 vs. 14.0, p <0.01) and less likely to have a penetrating injury (31% vs. 54%, p=0.02). The overall mortality was 49% and significantly higher in the VP (+) cohort (60% vs. 34%, AHR: 9.9, adjusted p=0.03). Mortality increased in a stepwise fashion with increasing number of VP utilized, starting at 34% for no VP, to 78% for 3 VP, and 100% for 5 or more. The majority of deaths in the VP (-) group (88%) occurred within one day from admission. For the VP (+) group, 57% of deaths occurred within one day, with the remaining 43% occurring at a later time.

CONCLUSION

In the era of massive transfusion protocols, vasopressors are commonly utilized in exsanguinating trauma patients and their use is associated with a higher mortality risk. Deaths in patients receiving vasopressors are more likely to occur later compared to those in patients who do not receive vasopressors. Further research to characterize the role of these agents in the resuscitation of trauma patients is required.

The Use of Lung Ultrasound in a Surgical Intensive Care Unit

Background

Pulmonary complications including pneumonia and pulmonary edema frequently develop in critically ill surgical patients. Lung ultrasound (LUS) is increasingly used as a powerful diagnostic tool for pulmonary complications. The purpose of this study was to report how LUS is used in a surgical intensive care unit (ICU).

Methods

This study retrospectively reviewed the medical records of 67 patients who underwent LUS in surgical ICU between May 2016 and December 2016.

Results

The indication for LUS included hypoxemia (n = 44, 65.7%), abnormal chest radiographs without hypoxemia (n = 17, 25.4%), fever without both hypoxemia and abnormal chest radiographs (n = 4, 6.0%), and difficult weaning (n = 2, 3.0%). Among 67 patients, 55 patients were diagnosed with pulmonary edema (n = 27, 41.8%), pneumonia (n = 20, 29.9%), diffuse interstitial pattern with anterior consolidation (n = 6, 10.9%), pneumothorax with effusion (n = 1, 1.5%), and diaphragm dysfunction (n = 1, 1.5%), respectively, via LUS. LUS results did not indicate lung complications for 12 patients. Based on the location of space opacification on the chest radiographs, among 45 patients with bilateral abnormality and normal findings, three (6.7%) and two (4.4%) patients were finally diagnosed with pneumonia and atelectasis, respectively. Furthermore, among 34 patients with unilateral abnormality and normal findings, two patients (5.9%) were finally diagnosed with pulmonary edema. There were 27 patients who were initially diagnosed with pulmonary edema via LUS. This diagnosis was later confirmed by other tests. There were 20 patients who were initially diagnosed with pneumonia via LUS. Among them, 16 and 4 patients were finally diagnosed with pneumonia and atelectasis, respectively.

Conclusions

LUS is useful to detect pulmonary complications including pulmonary edema and pneumonia in surgically ill patients.

Independent early predictors of mortality in polytrauma patients: a prospective, observational, longitudinal study

OBJECTIVES:

Trauma is an important public health issue and associated with substantial socioeconomic impacts and major adverse clinical outcomes. No single study has previously investigated the predictors of mortality across all stages of care (pre-hospital, emergency room, surgical center and intensive care unit) in a general trauma population. This study was designed to identify early predictors of mortality in severely injured polytrauma patients across all stages of care to provide a better understanding of the physiologic changes and mechanisms by which to improve care in this population.

METHODS:

A longitudinal, prospective, observational study was conducted between 2010 and 2013 in São Paulo, Brazil. Patients submitted to high-energy trauma were included. Exclusion criteria were as follows: injury severity score <16, <18 years old or insufficient data. Clinical and laboratory data were collected at four time points: pre-hospital, emergency room, and 3 and 24 hours after hospital admission. The primary outcome assessed was mortality within 30 days. Data were analyzed using tests of association as appropriate, nonparametric analysis of variance and generalized estimating equation analysis (p<0.05). ClinicalTrials.gov: NCT01669577.

RESULTS:

Two hundred patients were included. Independent early predictors of mortality were as follows: arterial hemoglobin oxygen saturation (p<0.001), diastolic blood pressure (p<0.001), lactate level (p<0.001), Glasgow Coma Scale score (p<0.001), infused crystalloid volume (p<0.015) and presence of traumatic brain injury (p<0.001).

CONCLUSION:

Our results suggest that arterial hemoglobin oxygen saturation, diastolic blood pressure, lactate level, Glasgow Coma Scale, infused crystalloid volume and presence of traumatic brain injury are independent early mortality predictors.

The impact of phosphate-balanced crystalloid infusion on acid-base homeostasis (PALANCE study): study protocol for a randomized controlled trial

Background

This study aims to investigate the effects of a modified, balanced crystalloid including phosphate in a perioperative setting in order to maintain a stable electrolyte and acid-base homeostasis in the patient.

Methods/design

This is a single-centre, open-label, randomized controlled trial involving two parallel groups of female patients comparing a perioperative infusion regime with sodium glycerophosphate and Jonosteril® (treatment group) or Jonosteril® (comparator) alone. The primary endpoint is to maintain a stable concentration of weak acids [A^-] according to the Stewart approach of acid-base balance. Secondary endpoints are measurement of serum phosphate levels, other acid-base parameters such as the strong ion difference (SID), the onset and severity of postoperative nausea and vomiting (PONV), electrolyte levels and their excretion in the urine, monitoring of renal function and glycocalyx components, haemodynamics, amounts of catecholamines and other vasopressors used and the safety of the infusion regime.

Discussion

Perioperative fluid replacement with the use of currently available crystalloid preparations still fail to maintain a stable acid-base balance and experts agree that common balanced solutions are still not ideal. This study aims to investigate the effectivity and safety of a new crystalloid solution by adding sodium glycerophosphate to a standardized crystalloid preparation in order to maintain a balanced perioperative acid-base homeostasis.

Trial registration

EudraCT number 201002422520. Registered on 30 November 2010.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2051-z) contains supplementary material, which is available to authorized users.

Fluid overload in children undergoing mechanical ventilation

Patients admitted to an intensive care unit are prone to cumulated fluid overload and receive intravenous volumes through the aggressive resuscitation recommended for septic shock treatment, as well as other fluid sources related to medications and nutritional support. The liberal liquid supply strategy has been associated with higher morbidity and mortality. Although there are few prospective pediatric studies, new strategies are being proposed. This non-systematic review discusses the pathophysiology of fluid overload, its consequences, and the available therapeutic strategies. During systemic inflammatory response syndrome, the endothelial glycocalyx is damaged, favoring fluid extravasation and resulting in interstitial edema. Extravasation to the third space results in longer mechanical ventilation, a greater need for renal replacement therapy, and longer intensive care unit and hospital stays, among other changes. Proper hemodynamic monitoring, as well as cautious infusion of fluids, can minimize these damages. Once cumulative fluid overload is established, treatment with long-term use of loop diuretics may lead to resistance to these medications. Strategies that can reduce intensive care unit morbidity and mortality include the early use of vasopressors (norepinephrine) to improve cardiac output and renal perfusion, the use of a combination of diuretics and aminophylline to induce diuresis, and the use of sedation and early mobilization protocols.

Association between fluid intake and mortality in critically ill patients with negative fluid balance: a retrospective cohort study

Background

Compared to positive fluid balance (FB), negative FB is associated with improved clinical outcomes in critically ill patients. However, as to whether achieving more negative FB can further improve outcomes has not been investigated. This study aimed to investigate whether more negative FB and restricted fluid intake were associated with improved outcomes in critically ill patients.

Method

Data were extracted from the Multi-parameter Intelligent Monitoring in Intensive Care III Database. Patients achieving negative FB at 48 hours after intensive care unit (ICU) admission were screened. The primary outcome was hospital mortality. Logistic models were built to explore the association between FB, fluid intake and mortality, using FB and fluid intake (both four levels) as design variables and using the linear spline function method.

Results

There were 2068 patients meeting the inclusion criteria. Compared to slight negative FB (level 1), there was a decreased tendency towards mortality with FB level 2 (OR 0.88, 95% CI 0.69–1.11) and level 3 (OR 0.79, 95% CI 0. 65–1.11); however, only extreme negative FB (level 4) was significant (OR 0.56, 95% CI 0. 33–0.95). Fluid intake and urine output were evenly distributed over the first 48 hours after ICU admission. Fluid intake was inversely associated with hospital mortality, with the OR decreased stepwise from level 2 (OR 0.73, 95% CI 0.56–0.96) to level 4 (OR 0.47, 95% CI 0.30–0.74), referred to level 1. Urine output also showed a similar pattern. Diuretic use was associated with higher mortality in both models.

Conclusion

In critically ill patients with negative FB, both increased fluid intake and urine output were associated with decreased hospital mortality. However, compared to slight FB, achieving more negative FB was not associated with reduced mortality.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1692-3) contains supplementary material, which is available to authorized users.

Hydroxyethyl starch resuscitation downregulate pro-inflammatory cytokines in the early phase of severe acute pancreatitis: A retrospective study

In the present study, we investigated the effects of hydroxyethyl starch (HES) 130/0.4 on serum pro-inflammatory variables, immunologic variables, fluid balance (FB)-negative(-) rate and renal function in severe acute pancreatitis (SAP) patients. From October, 2007 to November, 2008, a total of 120 SAP patients were enrolled in this retrospective study. Fifty-nine patients in the HES group received 6% HES 130/0.4 combined with crystalloid solution for fluid resuscitation (HES group). In the control group, 61 patients received only crystalloid solution after admission. Interleukin (IL)-1, IL-6, IL-8 and tumor necrosis factor (TNF)-α levels in serum were measured on days 1, 2, 4 and 8. The peripheral blood CD4+CD8+ T lymphocyte rates, serum BUN and Cr values were also measured on days 1, 4 and 8. Patients with FB(-) rates were recorded from day 1 to 8. Interaction term analysis (hospital stay and fluid resuscitation methods) based on mixed-effects regression model revealed significantly lower levels of IL-1 and TNF-α in the HES group compared with the control group. The difference in curve's risk ratio was not significant for IL-6, CD4+CD8+ T lymphocyte rate, BUN and Cr values (P>0.05). In the HES group, we detected a significantly higher rate of patients with FB(-) from day 4 to 8 (P<0.05). Thus, HES 130/0.4 resuscitation could decrease the IL-1 and IL-8 levels, shorten the duration of positive FB, and preserve the patient's immune status as well as renal function during the early phase of SAP.

Decreased maximum clot firmness in rotational thromboelastometry (ROTEM®) is associated with bleeding during extracorporeal mechanical circulatory support

BACKGROUND:

We aimed to characterize the coagulation disturbances which may increase the risk of bleeding, thrombosis or death shortly after implantation of an extracorporeal membrane oxygenation (ECMO) or ventricular assist (VAD) device.

METHODS:

Antithrombotic treatment was started in 23 VAD and 24 ECMO patients according to the hospital protocol. Additionally, conventional laboratory testing, rotational thromboelastometry (ROTEM®) and platelet function analysis (Multiplate®) were performed at predetermined intervals.

RESULTS:

Four out of twenty-four (16.7%) of ECMO patients and 6/23 (26.1%) of VAD patients had severe bleeding after the procedure. When all the patients were analyzed together, low maximum clot firmness (MCF) in ExTEM and FibTEM analyses was associated with severe bleeding (p<0.05) and low MCF in FibTEM with 30-day mortality. Low platelet count and hematocrit levels were also associated with severe bleeding. When VAD and ECMO patients were separated into different groups, the association between ROTEM® parameters, bleeding and survival was found only in limited time points. Four patients with VAD had cerebral ischemia indicative of thromboembolism. However, this had no significant correlation with ROTEM® or Multiplate® parameters.

CONCLUSION:

Hypocoagulation shown by ROTEM® was associated with bleeding complications in patients with mechanical circulatory support. In contrast, hypercoagulation did not correlate with clinical thrombosis.

Impact of hyperhydration on the mortality risk in critically ill patients admitted in intensive care units: comparison between bioelectrical impedance vector analysis and cumulative fluid balance recording

BACKGROUND

Studies have demonstrated a positive correlation between fluid overload (FO) and adverse outcomes in critically ill patients. The present study aims at defining the impact of hyperhydration on the Intensive Care Unit (ICU) mortality risk, comparing Bioelectrical Impedance Vector Analysis (BIVA) assessment with cumulative fluid balance (CFB) recording.

METHODS

We performed a prospective, dual-centre, clinician-blinded, observational study of consecutive patients admitted to ICU with an expected length of ICU stay of at least 72 hours. During observational period (72-120 hours), CFB was recorded and cumulative FO was calculated. At the admission and daily during the observational period, BIVA was performed. We considered FO between 5% and 9.99% as moderate and a FO ≥ 10% as severe. According to BIVA hydration scale of lean body mass, patients were classified as normohydrated (>72.7%-74.3%), mild (>71%-72.7%), moderate (>69%-71%) and severe (≤ 69%) dehydrated and mild (>74.3%-81%), moderate (>81%-87%) and severe (>87%) hyperhydrated. Two multivariate logistic regression models were performed: the ICU mortality was the response variable, while the predictor variables were hyperhydration, measured by BIVA (BIVA model), and FO (FO model). A p-value <0.05 was considered to indicate statistical significance.

RESULTS

One hundred and twenty-five patients were enrolled (mean age 64.8 ± 16.0 years, 65.6% male). Five hundred and fifteen BIVA measurements were performed. The mean CFB recorded at the end of the observational period was 2.7 ± 4.1 L, while the maximum hydration of lean body mass estimated by BIVA was 83.67 ± 6.39%. Severe hyperhydration measured by BIVA was the only variable found to be significantly associated with ICU mortality (OR 22.91; 95% CI 2.38-220.07; p < 0.01).

CONCLUSIONS

The hydration status measured by BIVA seems to predict mortality risk in ICU patients better than the conventional method of fluid balance recording. Moreover, it appears to be safe, easy to use and adequate for bedside evaluation. Randomized clinical trials with an adequate sample size are needed to validate the diagnostic properties of BIVA in the goal-directed fluid management of critically ill patients in ICU.

To use or not to use hydroxyethyl starch in intraoperative care: are we ready to answer the 'Gretchen question'?

PURPOSE OF REVIEW

The decision of the European Medicines Agency (EMA) against the use of hydroxyethyl starch (HES)-based volume replacement solutions in critically ill patients has led to a general uncertainty when dealing with HES-based solutions, even though HES-containing solutions can still be used for the treatment of hypovolaemia caused by acute (sudden) blood loss. This review discusses current evidence of the intraoperative use of HES-based solutions.

RECENT FINDINGS

HES solutions are often criticized for possible side-effects on the kidney, the coagulation system or tissue storage. Relevant differences exist between modern 6% HES 130/0.4 and older generation of starches. Because of pathophysiological differences between elective surgery and critical illness, the evidence on renal injury and coagulation impairment with HES administration cannot be generalized. Current data suggest that there is no clinically relevant impact of 6% HES 130/0.4 administration on perioperative renal function and coagulation. Over-resuscitation is a frequent problem associated with adverse outcomes. Due to the higher volume effect, fluid overload with HES is probably more harmful than with crystalloids, whereas goal-directed use of HES may be able to reduce intraoperative fluid accumulation and overload.

SUMMARY

The use of 6% HES 130/0.4 in elective surgery patients is associated with reduced fluid accumulation and no clinically relevant difference in bleeding or the rate of acute kidney injury as compared with crystalloid use alone. Current data do not allow a conclusion on mortality. As they provide no benefit, older starch preparations should not be used.