Improved outcome based on fluid management in critically ill patients requiring pulmonary artery catheterization

Fluid Management in Acute Respiratory Failure

Fluid management in acute respiratory failure is an area of uncertainty requiring a delicate balance of resuscitation and fluid removal to manage hypoperfusion and avoidance of hypoxemia. Overall, a restrictive fluid strategy (minimizing fluid administration) and careful attention to overall fluid balance may be beneficial after initial resuscitation and does not have major side effects. Further studies are needed to improve our understanding of patients who will benefit from a restrictive or liberal fluid management strategy.

Assessment of Extravascular Lung Water Using Lung Ultrasound in Critically Ill Patients Admitted to Intensive Care Unit

Background

Lung ultrasound (LUS) is a simple bedside tool to assess overhydration. Our study aimed to assess extravascular lung water (EVLW) using B-lines and correlate it with weaning, duration of mechanical ventilation, and mortality in critically ill patients admitted to the intensive care unit (ICU).

Patients and methods

150 mechanically ventilated ICU patients prospectively observed over 18 months, with their demographic and clinical data noted. Extravascular lung water was monitored using LUS in four intercostal spaces (ICS) from day 1 to day 5, day 7, day 10, and weekly thereafter. Pulmonary fluid burden was graded as low (1-10), moderate (11-20), and high (21-32). Weaning outcome, duration of weaning, mechanical ventilation, ICU stay, and mortality were compared in patients with and without EVLW.

Results

Out of 150, 54 patients (36.0%) had EVLW. The mean lung score amongst our patients was 8.57 ± 6.0. The mean time for detection of EVLW was 1.43 ± 2.24 days. Lung score was low in 40 (26.67%) patients, moderate in 9 (6.00%) patients, and high in 5 (3.33%) patients. Incidence of weaning failure (p-value = 0.006), duration of weaning, mechanical ventilation, ICU stay (p-value < 0.0001 each), and overall mortality were significantly higher in patients with EVLW (p-value = 0.006).

Conclusion

We conclude that a good proportion of critically ill patients have EVLW. Extravascular lung water significantly increases the duration of weaning, mechanical ventilation days, ICU stay, and overall mortality in critically ill patients.

How to cite this article

Rajpal M, Talwar V, Krishna B, Mustafi SM. Assessment of Extravascular Lung Water Using Lung Ultrasound in Critically Ill Patients Admitted to Intensive Care Unit. Indian J Crit Care Med 2024;28(2):165-169.

Effect of restrictive cumulative fluid balance on 28-day survival in invasively ventilated patients with moderate to severe ARDS due to COVID-19

This study aimed to evaluate the effect of two restrictive cumulative fluid balance (CFB) trends on survival and on major clinical outcomes in invasively ventilated patients with moderate to severe respiratory distress syndrome (ARDS) due to SARS-CoV-2. Prospective data collection was conducted on patients in the intensive care unit (ICU) originating from a tertiary university hospital. The primary outcomes were the risk association between the CFB trend during D0 to D7 and 28-day survival. The secondary outcomes were ICU mortality, in-hospital mortality, the need for invasive ventilation at D28, administration of vasoactive drugs at D7, time on invasive ventilation after D7, and length of ICU and hospital stay. 171 patients were enrolled in the study and divided according to their CFB trends during seven days of follow-up using model-based clustering [median CFB negative trend (n = 89) - 279 ml (- 664 to 203) and (n = 82) median CFB positive trend 1362 ml (619-2026)]. The group with CFB negative trend showed a higher chance of surviving 28-day in the ICU (HR: 0.62, 95% CI 0.41-0.94, p = 0.038). Moreover, this group had a reduced length of stay in the ICU, 11 (8-19) days versus 16.5 (9-29) days p = 0.004 and presented lower rates (OR = 0.22; 95% CI 0.09-0.52) of invasive ventilation after 28-days in the ICU. In patients invasively ventilated with moderate to severe ARDS due to COVID-19, the collective who showed a negative trend in the CFB after seven days of invasive ventilation had a higher chance of surviving 28 days in the ICU and lower length of stay in the ICU.

Relationship of Extravascular Lung Water and Pulmonary Vascular Permeability to Respiratory Mechanics in Patients with COVID-19-Induced ARDS

During acute respiratory distress syndrome (ARDS), the increase in pulmonary vascular permeability and lung water induced by pulmonary inflammation may be related to altered lung compliance. A better understanding of the interactions between respiratory mechanics variables and lung water or capillary permeability would allow a more personalized monitoring and adaptation of therapies for patients with ARDS. Therefore, our main objective was to investigate the relationship between extravascular lung water (EVLW) and/or pulmonary vascular permeability index (PVPI) and respiratory mechanic variables in patients with COVID-19-induced ARDS. This is a retrospective observational study from prospectively collected data in a cohort of 107 critically ill patients with COVID-19-induced ARDS from March 2020 to May 2021. We analyzed relationships between variables using repeated measurements correlations. We found no clinically relevant correlations between EVLW and the respiratory mechanics variables (driving pressure (correlation coefficient [CI 95%]: 0.017 [-0.064; 0.098]), plateau pressure (0.123 [0.043; 0.202]), respiratory system compliance (-0.003 [-0.084; 0.079]) or positive end-expiratory pressure (0.203 [0.126; 0.278])). Similarly, there were no relevant correlations between PVPI and these same respiratory mechanics variables (0.051 [-0.131; 0.035], 0.059 [-0.022; 0.140], 0.072 [-0.090; 0.153] and 0.22 [0.141; 0.293], respectively). In a cohort of patients with COVID-19-induced ARDS, EVLW and PVPI values are independent from respiratory system compliance and driving pressure. Optimal monitoring of these patients should combine both respiratory and TPTD variables.

Fluid balance control in critically ill patients: results from POINCARE-2 stepped wedge cluster-randomized trial

BACKGROUND

In critically ill patients, positive fluid balance is associated with excessive mortality. The POINCARE-2 trial aimed to assess the effectiveness of a fluid balance control strategy on mortality in critically ill patients.

METHODS

POINCARE-2 was a stepped wedge cluster open-label randomized controlled trial. We recruited critically ill patients in twelve volunteering intensive care units from nine French hospitals. Eligible patients were ≥ 18 years old, under mechanical ventilation, admitted to one of the 12 recruiting units for > 48 and ≤ 72 h, and had an expected length of stay after inclusion > 24 h. Recruitment started on May 2016 and ended on May 2019. Of 10,272 patients screened, 1361 met the inclusion criteria and 1353 completed follow-up. The POINCARE-2 strategy consisted of a daily weight-driven restriction of fluid intake, diuretics administration, and ultrafiltration in case of renal replacement therapy between Day 2 and Day 14 after admission. The primary outcome was 60-day all-cause mortality. We considered intention-to-treat analyses in cluster-randomized analyses (CRA) and in randomized before-and-after analyses (RBAA).

RESULTS

A total of 433 (643) patients in the strategy group and 472 (718) in the control group were included in the CRA (RBAA). In the CRA, mean (SD) age was 63.7 (14.1) versus 65.7 (14.3) years, and mean (SD) weight at admission was 78.5 (20.0) versus 79.4 (23.5) kg. A total of 129 (160) patients died in the strategy (control) group. Sixty-day mortality did not differ between groups [30.5%, 95% confidence interval (CI) 26.2-34.8 vs. 33.9%, 95% CI 29.6-38.2, p = 0.26]. Among safety outcomes, only hypernatremia was more frequent in the strategy group (5.3% vs. 2.3%, p = 0.01). The RBAA led to similar results.

CONCLUSION

The POINCARE-2 conservative strategy did not reduce mortality in critically ill patients. However, due to open-label and stepped wedge design, intention-to-treat analyses might not reflect actual exposure to this strategy, and further analyses might be required before completely discarding it. Trial registration POINCARE-2 trial was registered at ClinicalTrials.gov (NCT02765009). Registered 29 April 2016.

Lung Injury in COVID-19 Has Pulmonary Edema as an Important Component and Treatment with Furosemide and Negative Fluid Balance (NEGBAL) Decreases Mortality

The SARS-CoV2 promotes dysregulation of Renin-Angiotensin-Aldosterone. The result is excessive retention of water, producing a state of noxious hypervolemia. Consequently, in COVID-19 injury lung is pulmonary edema. Our report is a case-control study, retrospective. We included 116 patients with moderate-severe COVID-19 lung injury. A total of 58 patients received standard care (Control group). A total of 58 patients received a standard treatment with a more negative fluid balance (NEGBAL group), consisting of hydric restriction and diuretics. Analyzing the mortality of the population studied, it was observed that the NEGBAL group had lower mortality than the Control group, p = 0.001. Compared with Controls, the NEGBAL group had significantly fewer days of hospital stay (p < 0.001), fewer days of ICU stay (p < 0.001), and fewer days of IMV (p < 0.001). The regressive analysis between PaO₂/FiO₂BAL and NEGBAL demonstrated correlation (p = 0.04). Compared with Controls, the NEGBAL group showed significant progressive improvement in PaO₂/FiO₂ (p < 0.001), CT score (p < 0.001). The multivariate model, the vaccination variables, and linear trends resulted in p = 0.671 and quadratic trends p = 0.723, whilst the accumulated fluid balance is p < 0.001. Although the study has limitations, the promising results encourage more research on this different therapeutic approach, since in our research it decreases mortality.

The diuretic effect of adding aminophylline or theophylline to furosemide in pediatric populations: a systematic review

The diuretic effect of the combined furosemide and aminophylline/theophylline among pediatric patients remains unclear. The primary aim of this systematic review was to examine the clinical diuretic effects (urine output and fluid balance) of co-administration of furosemide and aminophylline/theophylline as compared to furosemide alone in pediatric population. Ovid MEDLINE, CENTRAL, and EMBASE were searched from its inception until March 2022 for observational studies and randomized controlled trials (RCTs) comparing the administration of furosemide versus furosemide and aminophylline/theophylline in pediatric population. Case reports, case series, commentaries, letters to editors, systematic reviews, and meta-analyses were excluded. Five articles with a total sample population of 187 patients were included in this systematic review. As compared to the furosemide alone, our pooled data demonstrated that co-administration of furosemide and aminophylline/theophylline was associated with higher urine output (mean difference: 2.91 [90% CI 1.54 to 4.27], p < 0.0001, I² = 90%) and a more negative fluid balance (mean difference - 28.27 [95% CI: - 46.21 to - 10.33], p = 0.002, I² = 56%) than those who received furosemide alone.

CONCLUSION

This is the first paper summarizing the evidence of combined use of furosemide with aminophylline/theophylline in pediatric population. Our systematic review demonstrated that the co-administration of furosemide and aminophylline/theophylline could potentially yield better diuretic effects of urine output and negative fluid balance than furosemide alone in pediatric patients with fluid overload. Given the substantial degree of heterogeneity and low level of evidence, future adequately powered trials are warranted to provide evidence regarding the combined use of aminophylline/theophylline and furosemide as diuretic in the pediatric population.

WHAT IS KNOWN

• Fluid overload is associated with poor prognosis for children in the intensive care unit. • The ineffective result of furosemide alone, even at high dose, as diuretic agent for children with diuretic resistant fluid overload in the intensive care unit.

WHAT IS NEW

• This is the first systematic review that compares furosemide alone and co-administration of furosemide and aminophylline/theophylline. • This paper showed potential benefit of co-administration of furosemide and aminophylline/theophylline promoting urine output and negative fluid balance compared to furosemide alone.

Fluid management in acute kidney injury: from evaluating fluid responsiveness towards assessment of fluid tolerance

Despite the widespread use of intravenous fluids in acute kidney injury (AKI), solid evidence is lacking. Intravenous fluids mainly improve AKI due to true hypovolaemia, which is difficult to discern at the bedside unless it is very pronounced. Empiric fluid resuscitation triggered only by elevated serum creatinine levels or oliguria is frequently misguided, especially in the presence of fluid intolerance syndromes such as increased extravascular lung water, capillary leak, intra-abdominal hypertension, and systemic venous congestion. While fluid responsiveness tests clearly identify patients who will not benefit from fluid administration (i.e. those without an increase in cardiac output), the presence of fluid responsiveness does not guarantee that fluid therapy is indicated or even safe. This review calls for more attention to the concept of fluid tolerance, incorporating it into a practical algorithm with systematic venous Doppler ultrasonography assessment to use at the bedside, thereby lowering the risk of detrimental kidney congestion in AKI.

Lung-kidney interactions and their role in chronic kidney disease-associated pulmonary diseases

Chronic illnesses rarely present in a vacuum, devoid of other complications, and chronic kidney disease is hardly an exception. Comorbidities associated with chronic kidney disease lead to faster disease progression, expedited dialysis dependency, and a higher mortality rate. Although chronic kidney disease is most commonly accompanied by cardiovascular diseases and diabetes, there is clear cross talk between the lungs and kidneys pH balance, phosphate metabolism, and immune system regulation. Our present understanding of the exact underlying mechanisms that contribute to chronic kidney disease-related pulmonary disease is poor. This review summarizes the current research on kidney-pulmonary interorgan cross talk in the context of chronic kidney disease, highlighting various acute and chronic pulmonary diseases that lead to further complications in patient care. Treatment options for patients presenting with chronic kidney disease and lung disease are explored by assessing activated molecular pathways and the body's compensatory response mechanisms following homeostatic imbalance. Understanding the link between the lungs and kidneys will potentially improve health outcomes for patients and guide healthcare professionals to better understand how and when to treat each of the pulmonary comorbidities that can present with chronic kidney disease.

Combining fluids and vasopressors: A magic potion?

Early detection and prompt reversal of sepsis-induced tissue hypoperfusion are key elements while treating patients with septic shock. Fluid administration is widely accepted as the first-line therapy followed by vasopressor use in persistently hypotensive patients or in those with insufficient arterial pressure to ensure adequate tissue perfusion. Recent evidence suggests a beneficial effect of combining fluids with vasopressors in the early phase of sepsis. Compared with fluids alone, combining fluids and vasopressors increases mean systemic pressure and venous return and corrects hypotension better. This approach also limits fluid overload, which is an independent factor of poor outcomes in sepsis. It produces less hemodilution than fluids alone. As a consequence of these effects, combined treatment may improve outcomes in septic shock patients.

A History of Fluid Management-From "One Size Fits All" to an Individualized Fluid Therapy in Burn Resuscitation

Fluid management is a cornerstone in the treatment of burns and, thus, many different formulas were tested for their ability to match the fluid requirements for an adequate resuscitation. Thereof, the Parkland-Baxter formula, first introduced in 1968, is still widely used since then. Though using nearly the same formula to start off, the definition of normovolemia and how to determine the volume status of burn patients has changed dramatically over years. In first instance, the invention of the transpulmonary thermodilution (TTD) enabled an early goal directed fluid therapy with acceptable invasiveness. Furthermore, the introduction of point of care ultrasound (POCUS) has triggered more individualized schemes of fluid therapy. This article explores the historical developments in the field of burn resuscitation, presenting different options to determine the fluid requirements without missing the red flags for hyper- or hypovolemia. Furthermore, the increasing rate of co-morbidities in burn patients calls for a more sophisticated fluid management adjusting the fluid therapy to the actual necessities very closely. Therefore, formulas might be used as a starting point, but further fluid therapy should be adjusted to the actual need of every single patient. Taking the developments in the field of individualized therapies in intensive care in general into account, fluid management in burn resuscitation will also be individualized in the near future.

Fluid administration and monitoring in ARDS: which management?

Modalities of fluid management in patients sustaining the acute respiratory distress syndrome (ARDS) are challenging and controversial. Optimal fluid management should provide adequate oxygen delivery to the body, while avoiding inadvertent increase in lung edema which further impairs gas exchange. In ARDS patients, positive fluid balance has been associated with prolonged mechanical ventilation, longer ICU and hospital stay, and higher mortality. Accordingly, a restrictive strategy has been compared to a more liberal approach in randomized controlled trials conducted in various clinical settings. Restrictive strategies included fluid restriction guided by the monitoring of extravascular lung water, pulmonary capillary wedge or central venous pressure, and furosemide targeted to diuresis and/or albumin replacement in hypoproteinemic patients. Overall, restrictive strategies improved oxygenation significantly and reduced duration of mechanical ventilation, but had no significant effect on mortality. Fluid management may require different approaches depending on the time course of ARDS (i.e., early vs. late period). The effects of fluid strategy management according to ARDS phenotypes remain to be evaluated. Since ARDS is frequently associated with sepsis-induced acute circulatory failure, the prediction of fluid responsiveness is crucial in these patients to avoid hemodynamically inefficient—hence respiratory detrimental—fluid administration. Specific hemodynamic indices of fluid responsiveness or mini-fluid challenges should be preferably used. Since the positive airway pressure contributes to positive fluid balance in ventilated ARDS patients, it should be kept as low as possible. As soon as the hemodynamic status is stabilized, correction of cumulated fluid retention may rely on diuretics administration or renal replacement therapy.

Furosemide use in Italian neonatal intensive care units: a national survey

Abstract

Background

Furosemide is approved in full term neonates to treat edema associated with congestive heart failure, cirrhosis and renal diseases. It is often administered off-label in premature neonates, to treat respiratory conditions and at doses greater-than-recommended. We conducted a national survey on behalf of the Neonatal Pharmacotherapy Study Group of the Italian Society of Neonatology (SIN), to investigate its use in Italian neonatal intensive care units (NICUs), in conformity with current guidelines.

Methods

Between December 2016 and June 2017, a 14-item multiple-choice online questionnaire was sent to all NICU directors from the SIN directory.

Gestational age, route of administration, posology, indications, referenced guidelines, adverse effects monitoring and the presence of Paediatric Cardiology or Cardiosurgery service on site were assessed. A chi-square test was performed 1) to evaluate differences in the distribution of responses between NICUs administering furosemide at doses higher-than-recommended; 2) to compare the proportion of NICUs administering furosemide at high doses in institutions with versus without a Paediatric Cardiology or Cardiosurgery service.

Results

The response rate was 50% (57/114). The intravenous and oral routes were chosen primarily; the intravenous administration in single doses predominated over continuous infusion. Its main therapeutic indications were congestive heart failure/overload (94.7%) and oligo-anuria (87.7%) however furosemide was also frequently used for broncopulmonary dysplasia (50.9%) and respiratory distress syndrome and/or transient tachypnea of the newborn (24.6%).

In 28/57 NICUs furosemide was administered at doses higher-than-recommended. In most NICUs the same posology was used in term and preterm neonates. Compared to the total sample, a larger proportion of NICUs administering doses greater-than-recommended referenced current literature for reasons to do so (19.3 and 32.1% respectively). The presence of a Paediatric Cardiology or Cardiosurgery service on site did not correlate with the chosen posology.

The majority of NICUs performed acoustic test and renal ultrasound for furosemide exposure greater than 2 weeks.

Conclusions

In Italian NICUs, furosemide is commonly prescribed to term and preterm newborns for label and unlabeled indications. Doses greater-than-recommended are frequently administered. Such use is not necessarily inappropriate. More research is required to assess the efficacy and safety of unlabeled use.

Use of Pulse Pressure Variation as Predictor of Fluid Responsiveness in Patients Ventilated With Low Tidal Volume: A Systematic Review and Meta-Analysis

Introduction:

Pulse pressure variation (PPV) has been shown to be useful to predict fluid responsiveness in patients ventilated at tidal volume (Vt) >8 mL kg−1. Nevertheless, most conditions in critical care force to use lower Vt. Thus, we sought to evaluate the operative performance of PPV when a Vt ⩽8 mL kg−1 is used during mechanical ventilation support.

Methods:

We searched PubMed and Embase databases for articles evaluating the operative performance of PPV as a predictor of fluid responsiveness in critical care and perioperative adult patients ventilated with tidal volume ⩽8 mL kg−1 without respiratory effort and arrhythmias, between January 1990 and January 2019. We included cohort and cross-sectional studies. Two authors performed an Independently selection using predefined terms of search. The fitted data of sensitivity, specificity, and area under the curve (AUC) were assessed by bivariate and hierarchical analyses.

Results:

We retrieved 19 trials with a total of 777 patients and a total of 935 fluid challenges. The fitted sensitivity of PPV to predict fluid responsiveness during mechanical ventilation at Vt ⩽8 mL kg−1 was 0.65 (95% confidence interval [CI]: 0.57-0.73), the specificity was 0.79 (95% CI: 0.73-0.84), and the AUC was 0.75. The diagnostic odds ratio was 5.5 (95% CI: 3.08-10.01, P < .001) by the random-effects model.

Conclusions:

Pulse pressure variation shows a fair operative performance as a predictor of fluid responsiveness in critical care and perioperative patients ventilated with a tidal volume ⩽8 mL kg−1 without respiratory effort and arrhythmias.

Use of Pulse Pressure Variation as Predictor of Fluid Responsiveness in Patients Ventilated With Low Tidal Volume: A Systematic Review and Meta-Analysis

INTRODUCTION

Pulse pressure variation (PPV) has been shown to be useful to predict fluid responsiveness in patients ventilated at tidal volume (Vt) >8 mL kg-1. Nevertheless, most conditions in critical care force to use lower Vt. Thus, we sought to evaluate the operative performance of PPV when a Vt ⩽8 mL kg-1 is used during mechanical ventilation support.

METHODS

We searched PubMed and Embase databases for articles evaluating the operative performance of PPV as a predictor of fluid responsiveness in critical care and perioperative adult patients ventilated with tidal volume ⩽8 mL kg-1 without respiratory effort and arrhythmias, between January 1990 and January 2019. We included cohort and cross-sectional studies. Two authors performed an Independently selection using predefined terms of search. The fitted data of sensitivity, specificity, and area under the curve (AUC) were assessed by bivariate and hierarchical analyses.

RESULTS

We retrieved 19 trials with a total of 777 patients and a total of 935 fluid challenges. The fitted sensitivity of PPV to predict fluid responsiveness during mechanical ventilation at Vt ⩽8 mL kg-1 was 0.65 (95% confidence interval [CI]: 0.57-0.73), the specificity was 0.79 (95% CI: 0.73-0.84), and the AUC was 0.75. The diagnostic odds ratio was 5.5 (95% CI: 3.08-10.01, P < .001) by the random-effects model.

CONCLUSIONS

Pulse pressure variation shows a fair operative performance as a predictor of fluid responsiveness in critical care and perioperative patients ventilated with a tidal volume ⩽8 mL kg-1 without respiratory effort and arrhythmias.

Thoracic Fluid Content (TFC) Measurement Using Impedance Cardiography Predicts Outcomes in Critically Ill Children

Objective: Conventional methods of fluid assessment in critically ill children are difficult and/or inaccurate. Impedance cardiography has capability of measuring thoracic fluid content (TFC). There is an insufficient literature reporting correlation between TFC and conventional methods of fluid balance and whether TFC predicts outcomes in critically ill children. We hypothesized that TFC correlates with indices of fluid balance [FIMO (Fluid Intake Minus Output) and AFIMO (Adjusted Fluid Intake Minus Output)] and is a predictor of outcomes in critically ill children. Design: Retrospective chart review. Setting: Pediatric intensive care unit of a tertiary care teaching hospital. Patients: Children <21 years, admitted to our Pediatric Intensive Care Unit (PICU) between July- November 2018 with acute respiratory failure and/or shock and who were monitored for fluid status using ICON® monitor. Interventions: None. Measurements and Main Results: We collected demographic information, data on daily and cumulative fluid balance (CFB), ventilator, PICU and hospital days, occurrence of multi-organ dysfunction syndrome (MODS), and mortality. We calculated AFIMO using insensible fluid loss. We analyzed data using correlation coefficient, chi-square test and multiple linear regression analysis. We analyzed a total 327 recordings of TFC, FIMO and AFIMO as daily records of fluid balance in 61 critically ill children during the study period. The initial TFC, FIMO, and AFIMO in ml [median (IQR)] were 30(23, 44), 300(268, 325), and 21.05(-171.3, 240.2), respectively. The peak TFC, FIMO, and AFIMO in ml were 36(26, 24), 322(286, 334), and 108.8(-143.6, 324.4) respectively. The initial CFB was 1134.2(325.6, 2774.4). TFC did not correlate well with FIMO or AFIMO (correlation coefficient of 0.02 and -0.03, respectively), but a significant proportion of patients with high TFC exhibited pulmonary plethora on x-ray chest (as defined by increased bronchovascular markings and/or presence of pleural effusion) (p = 0.015). The multiple linear regression analysis revealed that initial and peak TFC and peak and mean FIMO and AFIMO predicted outcomes (ventilator days, length of PICU, and hospital days) in critically ill children (p < 0.05). Conclusions: In our cohort of critically ill children with respiratory failure and/or shock, TFC did not correlate with conventional measures of fluid balance (FIMO/AFIMO), but a significant proportion of patients with high TFC had pulmonary plethora on chest x-ray. Both initial and peak TFC predicted outcomes in critically ill children.

Critical hemodynamic therapy oriented resuscitation helping reduce lung water production and improve survival

BACKGROUND

Increased extravascular lung water (EVLW) in shock is common in the critically ill patients. This study aimed to explore the effect of cardiac output (CO) on EVLW and its relevant influence on prognosis.

METHODS

The hemodynamic data of 428 patients with pulse-indicated continuous CO catheterization from Department of Critical Care Medicine, Peking Union Medical College Hospital were retrospectively collected and analyzed. The patients were assigned to acute respiratory distress syndrome group, cardiogenic shock group, septic shock group, and combined shock (cardiogenic and septic) group according to their symptoms. Information on 28-day mortality and renal function was also collected.

RESULTS

The CO and EVLW index (EVLWI) in the cardiogenic and combined shock groups were lower than those in the other groups (acute respiratory distress syndrome group vs. cardiogenic shock group vs. septic shock group vs. combined shock group: CO, 5.1 [4.0, 6.2] vs. 4.7 [4.0, 5.7] vs. 5.5 [4.3, 6.7] vs. 4.6 [3.5, 5.7] at 0 to 24 h, P = 0.009; 4.6 [3.8, 5.6] vs. 4.8 [4.1, 5.7] vs. 5.3 [4.4, 6.5] vs. 4.5 [3.8, 5.3] at 24 to 48 h, P = 0.048; 4.5 [4.1, 5.4] vs. 4.8 [3.8, 5.5] vs. 5.3 [4.0, 6.4] vs. 4.0 [3.2, 5.4] at 48 to 72 h, P = 0.006; EVLWI, 11.4 [8.7, 19.1] vs. 7.9 [6.6, 10.0] vs. 8.8 [7.4, 11.0] vs. 8.2 [6.7, 11.3] at 0 to 24 h, P < 0.001; 11.8 [7.7, 17.2] vs. 7.8 [6.3, 10.2] vs. 8.7 [6.6, 12.2] vs. 8.0 [6.6, 11.1] at 24 to 48 h, P < 0.001; and 11.3 [7.7, 18.7] vs. 7.5 [6.3, 10.0] vs. 8.8 [6.3, 12.2] vs. 8.4 [6.4, 11.2] at 48 to 72 h, P < 0.001. The trend of the EVLWI in the septic shock group was higher than that in the cardiogenic shock group (P < 0.05). Moreover, there existed some difference in the pulmonary vascular permeability index among the cardiogenic shock group, the septic shock group, and the combined shock group, without statistical significance (P > 0.05). In addition, there was no significant difference in tissue perfusion or renal function among the four groups during the observation period (P > 0.05). However, the cardiogenic shock group had a higher 28-day survival rate than the other three groups [log rank (Mantel-Cox) = 31.169, P < 0.001].

CONCLUSION

Tissue-aimed lower CO could reduce the EVLWI and achieve a better prognosis.

Are management decisions in critical patients changed with use of hemodynamic parameters from transpulmonary thermodilution technique?

Background

The assessment of hemodynamic variables is a mainstay in the management of critically ill patients. Hemodynamic variables may help physicians to choose among use of a vasopressor, an inotropic agent, or discontinuation of drugs. In this study, we aimed to investigate the usefulness of advanced hemodynamic variables in clinical decision-making.

Methods

Surveys regarding the case were administered to 25 surgeons working in nationally designated trauma centers or on trauma teams, using a voting system at a medical conference. The patient was a 67-year-old male with a crush injury of the left leg after a pedestrian traffic accident, who had aggravated pulmonary edema after leg amputation. Three clinical situations were given and the decision choices were: immediately after amputation, in 8 hours, and on the second day after amputation. Three kinds of variables from hemodynamic monitoring systems were provided for each clinical situation: conventional hemodynamic variables, including central venous pressure; variables from pulse contour analysis (PCA) [cardiac output (CO), stroke volume index, stroke volume variation (SVV), and systemic vascular resistance index); and variables from transpulmonary thermodilution (TPTD) technique (global ejection fraction and extravascular lung water index). The changes in decisions according to each provided hemodynamic variable were investigated and analyzed.

Results

The advanced hemodynamic parameters were considered to have a decisive effect on choosing vasopressors and inotropic agents. The decision was changed in 88% (22/25) of physicians using variables from the advanced monitoring systems. Among them, 82% (18/22) of physicians chose hemodynamic variables from the TPTD technique as their reason for change regarding management of a patient with severe pulmonary edema.

Conclusions

Advanced monitoring systems might be helpful in decision-making for critically ill patients. Multiple parameters and trends in change could be more important than a single value. Clinicians should select the system most appropriate according to its advantages and limitations, and interpret the variables obtained correctly.

Effect of fluid balance control in critically ill patients: Design of the stepped wedge trial POINCARE-2

A high number of recent studies have shown that a positive fluid balance is independently associated with impaired prognosis in specific populations of patients hospitalized in intensive care unit (ICU): acute kidney injury, acute respiratory distress syndrome (ARDS), sepsis, high risk surgery. However, to date, there is no evidence that control of fluid overload reduces mortality in critically ill patients. The main objective is to assess the efficacy of a strategy limiting fluid overload on mortality in unselected critically ill patients hospitalized in ICU. We hypothesized that a strategy based on a weight-driven recommendation of restricted fluid intake, diuretics, and ultrafiltration initiated from 48 h up to 14 days after admission in critically ill patients would reduce all-cause mortality as compared to usual care. We use a stepped wedge cluster randomized controlled trial combined with a quasi-experimental (before-and-after) study. Patients under mechanical ventilation, admitted since >48 h and < 72 h in ICU, and with no discharge planned for the next 24 h are eligible. A total of 1440 patients are expected to be enrolled in 12 ICUs. Sociodemographic and clinical data are collected at inclusion, and outcomes are collected during the follow-up. Primary outcome is all-cause mortality at 60 days after admission. Secondary outcomes are patients weight differences between admission and day7 (or day 14), 28-day, in-hospital, and 1-year mortality, end-organ damages, and unintended harmful events. Analyses will be held in intention-to-treat. If POINCARE-2 strategy proves effective, then guidelines on fluid balance control might be extended to all critically ill patients. Trial registration: ClinicalTrials.govNCT02765009.

Furosemide Exposure and Prevention of Bronchopulmonary Dysplasia in Premature Infants

OBJECTIVE

To evaluate the association between furosemide exposure and risk of bronchopulmonary dysplasia (BPD).

STUDY DESIGN

This retrospective cohort study included infants (2004-2015) born at 23-29 weeks gestational age and 501-1249 g birth weight. We compared the demographic and clinical characteristics of infants exposed and not exposed to furosemide between postnatal day 7 and 36 weeks postmenstrual age. We examined the association between furosemide exposure and 2 outcomes: BPD and BPD or death. We performed multivariable probit regression models that included demographic and clinical variables in addition to 2 instrumental variables: furosemide exposure by discharge year, and furosemide exposure by site.

RESULTS

Of 37 693 included infants, 19 235 (51%) were exposed to furosemide; these infants were more premature and had higher respiratory support. Of 33 760 infants who survived to BPD evaluation, 15 954 (47%) had BPD. An increase in the proportion of furosemide exposure days by 10 percentage points was associated with a decrease in both the incidence of BPD (4.6 percentage points; P = .001), and BPD or death (3.7 percentage points; P = .01).

CONCLUSIONS

More days of furosemide exposure between postnatal day 7 and 36 weeks was associated with decreased risk of BPD and a combined outcome of BPD or death.

Extravascular lung water monitoring for thoracic and lung transplant surgeries

PURPOSE OF REVIEW

Excessive accumulation of extravascular lung water (EVLW) resulting in pulmonary edema is the most feared complication following thoracic surgery and lung transplant. ICUs have long relied on chest radiography to monitor pulmonary status postoperatively but the increasing recognition of the limitations of bedside plain films has fueled development of newer technologies, which offer earlier detection, quantitative assessments, and can aide in preoperative screening of surgical candidates. In this review, we focus on the emergence of transpulmonary thermodilution (TPTD) and lung ultrasound with a focus on the clinical integration of these modalities into current intraoperative and critical care practices.

RECENT FINDINGS

Recent studies demonstrate transpulmonary thermodilution and lung ultrasound provide greater sensitivity and earlier detection of lung water accumulation and are useful to guide clinical management. Assessments from these techniques have predictive value of postoperative outcome. Further, EVLW assessment shows promise as a preoperative screening tool in lung transplant patients.

SUMMARY

Monitoring EVLW in the perioperative period offers clinicians a powerful tool to guide fluid therapy and manage pulmonary edema. Both TPTD and lung ultrasound have unique attributes in the care of thoracic surgery and lung transplant patients.

Clinical Features and Indications Associated with Mortality in Continuous Renal Replacement Therapy for Pediatric Patients

OBJECTIVES

To identify prognostic factors and indications in patients receiving continuous renal replacement therapy (CRRT) in the pediatric intensive care unit (PICU), and to demonstrate their effect on mortality.

METHODS

A total of 63 patients admitted between 2011 and 2014 were included in the study. The demographic information, pediatric risk of mortality (PRISM) scores, vasoactive-inotropic score, indication for CRRT, time of starting CRRT, presence of fluid overload, durations of CRRT, and pediatric intensive care unit (PICU) stay were compared between survivors and non-survivors.

RESULTS

The overall rate of survival was 69,8%. The most common indication for CRRT was fluid overload (31.7%) followed by acute attacks of metabolic diseases (15.9%), and resistant metabolic acidosis (15.9%). The median duration of CRRT was 58 (IQR 24-96) h. The most common CRRT modality was continuous venovenous hemodiafiltration. The CRRT modality was not different between survivors and nonsurvivors. Sepsis, as the diagnosis for admission to intensive care unit was significantly related to decreased survival when compared to acute kidney injury and acute attacks of metabolic diseases. Patients with fluid overload had significantly increased rate of death, CRRT duration, use of mechanical ventilation, and PICU stay.

CONCLUSIONS

The CRRT, can be effectively used for removal of fluid overload, treatment of acute attacks of metabolic diseases, and other indications in critically ill pediatric patients. It has a positive effect on mortality in high-risk PICU patients. This treatment modality can be used more frequently in pediatric intensive care unit with improved patient outcomes, and should be focused on starting therapy in early stages of fluid overload.

Fluid Management in Acute Respiratory Distress Syndrome

One of the defining features of acute respiratory distress syndrome (ARDS) is noncardiogenic pulmonary edema, resulting from increased permeability of the alveolar-capillary barrier and passage of protein-rich fluid into the interstitium and alveolar spaces. The loss of protein from the intravascular space disrupts the normal oncotic pressure differential and causes patients with ARDS to be particularly sensitive to the hydrostatic forces that correlate with intravascular volume. Conservative fluid management, in which diuretics are administered and intravenous fluid administration is minimized, may decrease hydrostatic pressure and increase serum oncotic pressure, potentially limiting the development of pulmonary edema. However, the cause of death in most patients with ARDS is multiorgan system failure, not hypoxemia, and the impact of conservative fluid management on the incidence of extrapulmonary organ failure during ARDS is unclear. These physiologic observations have led to a series of studies examining the impact of fluid management on the development of, resolution of, survival from, and long-term outcomes from ARDS. While questions remain, the current literature makes it clear that fluid management is an integral part of the care of patients with ARDS.

Correlation between Extravascular Lung Water and Oxygenation in ALI/ARDS Patients in Septic Shock: Possible Role in the Development of Atelectasis?

This study aimed to evaluate the relationship between PaO2/FiO2 ratio and extravascular lung water in septic shock-induced acute respiratory distress syndrome in a prospective observational clinical trial.

Twenty-three patients suffering from sepsis induced acute respiratory distress syndrome were recruited. All patients were ventilated in pressure control/support mode. Haemodynamic parameters were determined by arterial thermodilution (PiCCO) eight hourly for 72 hours. At the same time blood gas analyses were done and respiratory parameters were also recorded. Data are presented as mean±SD. For statistical analysis Pearson's correlation test, and analysis of variance (ANOVA) was used respectively.

Significant negative correlation was found between extravascular lung water and PaO2/FiO2 (r= −0.355, P<0.001), and significant positive correlation was shown between extravascular lung water and PEEP (r=0.557, P<0.001). A post-hoc analysis was performed when “low” PEEP: <10 cmH2O and “high” PEEP: (10 cmH2O PEEP was applied, and neither the oxygenation, nor the driving pressure or the PaCO2 differed significantly, but the extravascular lung water showed significant difference when “high” or “low” PEEP was applied (13±5 vs 9±2 ml/kg respectively, P=0.001).

This study found significant negative correlation between extravascular lung water and PaO2/FiO2. The mechanism by which extravascular lung water affects oxygenation is unknown but the significant positive correlation between PEEP and extravascular lung water shown in this trial suggests that the latter may have a role in the development of alveolar atelectasis.

Inflammation and lung injury in an ovine model of fluid resuscitated endotoxemic shock

Background

Sepsis is a multi-system syndrome that remains the leading cause of mortality and critical illness worldwide, with hemodynamic support being one of the cornerstones of the acute management of sepsis. We used an ovine model of endotoxemic shock to determine if 0.9% saline resuscitation contributes to lung inflammation and injury in acute respiratory distress syndrome, which is a common complication of sepsis, and investigated the potential role of matrix metalloproteinases in this process.

Methods

Endotoxemic shock was induced in sheep by administration of an escalating dose of lipopolysaccharide, after which they subsequently received either no fluid bolus resuscitation or a 0.9% saline bolus. Lung tissue, bronchoalveolar fluid (BAL) and plasma were analysed by real-time PCR, ELISA, flow cytometry and immunohistochemical staining to assess inflammatory cells, cytokines, hyaluronan and matrix metalloproteinases.

Results

Endotoxemia was associated with decreased serum albumin and total protein levels, with activated neutrophils, while the glycocalyx glycosaminoglycan hyaluronan was significantly increased in BAL. Quantitative real-time PCR studies showed higher expression of IL-6 and IL-8 with saline resuscitation but no difference in matrix metalloproteinase expression. BAL and tissue homogenate levels of IL-6, IL-8 and IL-1β were elevated.

Conclusions

This data shows that the inflammatory response is enhanced when a host with endotoxemia is resuscitated with saline, with a comparatively higher release of inflammatory cytokines and endothelial/glycocalyx damage, but no change in matrix metalloproteinase levels.

Crystalloid fluid administration was associated with outcomes in pediatric patients with severe sepsis or septic shock

Intravenous fluid prescription plays an important role in sepsis management, which may be associated with patient prognosis. The objective of the present study was to determine if the administration of crystalloid fluids is associated with clinical outcome for patients with severe sepsis and septic shock.The medical records of 79 patients with severe sepsis or septic shock at an academic tertiary care hospital between 2011 and 2016 were reviewed retrospectively. The patients were dichotomized based on the median 3-day amount of corrected crystalloid fluids as low (<193 mL/kg) versus high (>193 mL/kg). The primary outcome measure was mortality. Secondary outcome measures included length of stay in the pediatric intensive care unit (PICU), usage of mechanical ventilation, etc.The most common bacterial pathogens were Escherichia coli and Klebsiella spp. with a strikingly high number of multidrug-resistant infections (10.1%). The most common site of infection was of abdominal origin. Patients who received larger amounts of crystalloids were more likely to have lower weight and underlying comorbidities (high PRISM score). Although fluid intake was different in the 2 groups, output volumes were almost the same; therefore, a positive fluid balance was present in the high crystalloid patients. The incidence of mortality increased as the accumulated 3-day amount of crystalloid fluids administered increased. The total length of stay in the PICU was longer for patients who received high volume crystalloid fluid (15.8 ± 7.8 days) than for patients who received the lower volume (9.7 ± 5.3 days, P = .026).A higher amount of 3-day crystalloid administration was unfavorable for postoperative outcomes in children with sepsis and septic shock; these patients experienced higher PICU mortality, longer PICU stays, and more ventilator days. More study on the benefits and harms of fluid in children are needed to improve patient safety and the quality of care that would facilitate better outcomes.

Effect of hemodialysis on respiratory mechanics in acute kidney injury patients

INTRODUCTION

Hemodialysis (HD) is one treatment for acute kidney injury (AKI) patients. Studies have shown that this dialysis modality may lead to changes in pulmonary function with an impact on prognosis. The aim of our study was to evaluate changes in respiratory mechanics and oxygenation of AKI patients admitted to an intensive care unit who were undergoing intermittent mechanical ventilation (IMV) and daily HD.

METHODS

This prospective cohort study evaluated 94 AKI patients and 234 HD sessions. Pulmonary static compliance (Pcs), resistance (Rsr), and arterial partial pressure of oxygen and the fraction of inspired oxygen (PaO₂ /FiO₂ ) ratio were assessed during the initial three-day period of daily HD therapy.

FINDINGS

Psc increased progressively during HD sessions, from 39.4 ± 21.4 mL/cm H₂ O prior to the initial dialysis to 55.5 ± 25.2 at the end of the last dialysis during the study period (P = 0.04). Similarly, Rsr and PaO₂ /FiO₂ ratio also improved, from 11.1 ± 6.3 cm H₂ O/L/s prior to the initial dialysis to 8.8 ± 4.2 at the end of the last dialysis (P =0.0027) and from 228 ± 85 prior to the initial dialysis to 312.1 ± 111.5, P < 0.001, to the end of the last dialysis, respectively.

CONCLUSION

This study showed that AKI patients undergoing IMV and daily HD improve their respiratory mechanics and oxygenation.

Forced fluid removal in intensive care patients with acute kidney injury: The randomised FFAKI feasibility trial

BACKGROUND

Accumulation of fluids is frequent in intensive care unit (ICU) patients with acute kidney injury and may be associated with increased mortality and decreased renal recovery. We present the results of a pilot trial assessing the feasibility of forced fluid removal in ICU patients with acute kidney injury and fluid accumulation of more than 10% ideal bodyweight.

METHODS

The FFAKI-trial was a pilot trial of forced fluid removal vs standard care in adult ICU patients with moderate to high risk acute kidney injury and 10% fluid accumulation. Fluid removal was done with furosemide and/or continuous renal replacement therapy aiming at net negative fluid balance > 1 mL/kg ideal body weight/hour until cumulative fluid balance calculated from ICU admission reached less than 1000 mL.

RESULTS

After 20 months, we stopped the trial prematurely due to a low inclusion rate with 23 (2%) included patients out of the 1144 screened. Despite the reduced sample size, we observed a marked reduction in cumulative fluid balance 5 days after randomisation (mean difference -5814 mL, 95% CI -2063 to -9565, P = .003) with forced fluid removal compared to standard care. While the trial was underpowered for clinical endpoints, no point estimates suggested harm from forced fluid removal.

CONCLUSIONS

Forced fluid removal aiming at 1 mL/kg ideal body weight/hour may be an effective treatment of fluid accumulation in ICU patients with acute kidney injury. A definitive trial using our inclusion criteria seems less feasible based on our inclusion rate of only 2%.

Bedside sonography assessment of extravascular lung water increase after major pulmonary resection in non-small cell lung cancer patients

Background

Extra vascular lung water (EVLW) following pulmonary resection increases due to fluid infusion and rises in capillary surface and permeability of the alveolar capillary membranes. EVLW increase clinically correlates to pulmonary oedema and it may generate impairments of gas exchanges and acute lung injury. An early and reliable assessment of postoperative EVLW, especially following major pulmonary resection, is useful in terms of reducing the risk of postoperative complications. The currently used methods, though satisfying these criteria, tend to be invasive and cumbersome and these factors might limit its use. The presence and burden of EVLW has been reported to correlate with sonographic B-line artefacts (BLA) assessed by lung ultrasound (LUS). This observational study investigated if bedside LUS could detect EVLW increases after major pulmonary resection. Due to the clinical association between EVLW increase and impairment of gas exchange, secondary aims of the study included investigating for associations between any observed EVLW increases and both respiratory ratio (PaO₂/FiO₂) and fluid retention, measured by brain natriuretic peptide (BNP).

Methods

Overall, 74 major pulmonary resection patients underwent bedside LUS before surgery and at postoperative days 1 and 4, in the inviolate hemithorax which were divided into four quadrants. BLA were counted with a four-level method. The respiratory ratio PaO₂/FiO₂ and fluid retention were both assessed.

Results

BLA resulted being increased at postoperative day 1 (OR 9.25; 95% CI, 5.28-16.20; P<0.0001 vs. baseline), and decreased at day 4 (OR 0.50; 95% CI, 0.31-0.80; P=0.004 vs. day 1). Moreover, the BLA increase was associated with both increased BNP (OR 1.005; 95% CI, 1.003-1.008; P<0.0001) and body weight (OR 1.040; 95% CI, 1.008-1.073; P=0.015). Significant inverse correlations were observed between the BLA values and the PaO₂/FiO₂ respiratory ratios.

Conclusions

Our results suggest that LUS, due to its non-invasiveness, affordability and capacity to detect increases in EVLW, might be useful in better managing postoperative patients.

My patient has received fluid. How to assess its efficacy and side effects?

Many efforts have been made to predict, before giving fluid, whether it will increase cardiac output. Nevertheless, after fluid administration, it is also essential to assess the therapeutic efficacy and to look for possible adverse effects. Like for any drug, this step should not be missed. Basically, volume expansion is aimed at improving tissue oxygenation and organ function. To assess this final result, clinical signs are often unhelpful. The increase in urine output in case of acute kidney injury is a poor marker of the kidney perfusion improvement. Even if oxygen delivery has increased with fluid, the increase in oxygen consumption is not constant. Assessing this response needs to measure markers such as lactate, central/mixed venous oxygen saturation, or carbon dioxide-derived indices. If tissue oxygenation did not improve, one should check that cardiac output has actually increased with fluid administration. To assess this response, changes in arterial pressure are not reliable enough, and direct measurements of cardiac output are required. In cases where cardiac output did not increase with fluid, one should check that it was not due to an insufficient volume of fluid administered. For this purpose, volume markers of cardiac preload sometimes lack precision. The central venous pressure, in theory at least, should not augment to a large extent in fluid responders. The worst adverse effect of fluids is the increase in the cumulative fluid balance. In patients with acute respiratory distress syndrome (ARDS), the risk of aggravating pulmonary oedema should be systematically assessed by looking for increases in extravascular lung water, or, more indirectly, increases in central venous or pulmonary artery occlusion pressure. In ARDS patients receiving fluid, one should always keep in mind the risk of inducing/aggravating right ventricular dilation, which should be confirmed through echocardiography. The risk of increasing the intra-abdominal pressure should be carefully sought in patients at risk. Finally, fluid-induced haemodilution should not be neglected. Like for any drug which has inconsistent effectiveness and may exert significant harm, the correct fluid management should include a cautious and comprehensive assessment of fluid-induced benefits and side effects.

Pulmonary Circulation Transvascular Fluid Fluxes Do Not Change during General Anesthesia in Dogs

General anesthesia (GA) can cause abnormal lung fluid redistribution. Pulmonary circulation transvascular fluid fluxes (J_VA) are attributed to changes in hydrostatic forces and erythrocyte volume (EV) regulation. Despite the very low hydraulic conductance of pulmonary microvasculature it is possible that GA may affect hydrostatic forces through changes in pulmonary vascular resistance (PVR), and EV through alteration of erythrocyte transmembrane ion fluxes (_ionJ_VA). Furosemide (Fur) was also used because of its potential to affect pulmonary hydrostatic forces and _ionJ_VA. A hypothesis was tested that J_VA, with or without furosemide treatment, will not change with time during GA. Twenty dogs that underwent castration/ovariectomy were randomly assigned to Fur (n = 10) (4 mg/kg IV) or placebo treated group (Con, n = 10). Baseline arterial (BL) and mixed venous blood were sampled during GA just before treatment with Fur or placebo and then at 15, 30 and 45 min post-treatment. Cardiac output (Q) and pulmonary artery pressure (P_AP) were measured. J_VA and _ionJ_VA were calculated from changes in plasma protein, hemoglobin, hematocrit, plasma and whole blood ions, and Q. Variables were analyzed using random intercept mixed model (P < 0.05). Data are expressed as means ± SE. Furosemide caused a significant volume depletion as evident from changes in plasma protein and hematocrit (P < 0.001). However; Q, P_AP, and J_VA were not affected by time or Fur, whereas erythrocyte fluid flux was affected by Fur (P = 0.03). Furosemide also affected erythrocyte transmembrane K⁺ and Cl⁻, and transvascular Cl⁻ metabolism (P ≤ 0.05). No other erythrocyte transmembrane or transvascular ion fluxes were affected by time of GA or Fur. Our hypothesis was verified as J_VA was not affected by GA or ion metabolism changes due to Fur treatment. Furosemide and 45 min of GA did not cause significant hydrostatic changes based on Q and P_AP. Inhibition of Na⁺/K⁺/2Cl⁻ cotransport caused by Fur treatment, which can alter EV regulation and J_VA, was offset by the Jacobs Stewart cycle. The results of this study indicate that the Jacobs Stewart cycle/erythrocyte Cl⁻ metabolism can also act as a safety factor for the stability of lung fluid redistribution preserving optimal diffusion distance across the blood gas barrier.

Continuous Infusion versus Intermittent Bolus Injection of Furosemide in Critically Ill Patients: A Systematic Review and Meta-analysis

OBJECTIVE

Fluid overload is a common phenomenon seen in intensive care units (ICUs). However, there is no general consensus on whether continuous or bolus furosemide is safer or more effective in these hemodynamically unstable ICU patients. The aim of this meta-analysis was to examine the clinical outcomes of continuous versus bolus furosemide in a critically ill population in ICUs.

DATA SOURCES

MEDLINE, EMBASE, PubMed, and the Cochrane Database of Systematic reviews were searched from their inception until June 2017.

REVIEW METHODS

All randomized controlled trials, observational studies, and case-control studies were included. Case reports, case series, nonsystematic reviews, and studies that involved children were excluded.

RESULTS

Nine studies (n = 464) were eligible in the data synthesis. Both continuous and bolus furosemide resulted in no difference in all-cause mortality (7 studies; n = 396; I² = 0%; fixed-effect model [FEM]: odds ratio [OR] 1.15 [95% confidence interval (CI) 0.67-1.96]; p = 0.64). Continuous furosemide was associated with significant greater total urine output (n = 132; I² = 70%; random-effect model: OR 811.19 [95% CI 99.84-1,522.53]; p = 0.03), but longer length of hospital stay (n = 290; I² = 40%; FEM: OR 2.84 [95% CI 1.74-3.94]; p < 0.01) in comparison to the bolus group. No statistical significance was found in the changes of creatinine and estimated glomerular filtration rate between both groups.

CONCLUSIONS

In this meta-analysis, continuous furosemide was associated with greater diuretic effect in total urine output as compared with bolus. Neither had any differences in mortality and changes of renal function tests. However, a large adequately powered randomized clinical trial is required to fill this knowledge gap.

Fluid and Volume Monitoring

Background

Fluid resuscitation is not only used to prevent acute kidney injury (AKI) but fluid management is also a cornerstone of treatment for patients with established AKI and renal failure. Ultrafiltration removes volume initially from the intravascular compartment inducing a relative degree of hypovolemia. Normal reflex mechanisms attempt to sustain blood pressure constant despite marked changes in blood volume and cardiac output. Thus, compensated shock with a normal blood pressure is a major cause of AKI or exacerbations of AKI during ultrafiltration.

Methods

We undertook a systematic review of the literature using MEDLINE, Google Scholar and PubMed searches. We determined a list of key questions and convened a 2-day consensus conference to develop summary statements via a series of alternating breakout and plenary sessions. In these sessions, we identified supporting evidence and generated clinical practice recommendations and/or directions for future research.

Results

We defined three aspects of fluid monitoring: i) normal and pathophysiological cardiovascular mechanisms; ii) measures of volume responsiveness and impending cardiovascular collapse during volume removal, and; iii) measured indices of each using non-invasive and minimally invasive continuous and intermittent monitoring techniques. The evidence documents that AKI can occur in the setting of normotensive hypovolemia and that under-resuscitation represents a major cause of both AKI and mortality ion critically ill patients. Traditional measures of intravascular volume and ventricular filling do not predict volume responsiveness whereas dynamic functional hemodynamic markers, such as pulse pressure or stroke volume variation during positive pressure breathing or mean flow changes with passive leg raising are highly predictive of volume responsiveness. Numerous commercially-available devices exist that can acquire these signals.

Conclusions

Prospective clinical trials using functional hemodynamic markers in the diagnosis and management of AKI and volume status during ultrafiltration need to be performed. More traditional measure of preload be abandoned as marked of volume responsiveness though still useful to assess overall volume status.

Fluid Overload and Renal Angina Index at Admission Are Associated With Worse Outcomes in Critically Ill Children

Objectives: We investigated the association of fluid overload and oxygenation in critically sick children, and their correlation with various outcomes (duration of ventilation, ICU stay, and mortality). We also assessed whether renal angina index (RAI) at admission can predict mortality or acute kidney injury (AKI) on day 3 after admission. Design and setting: Prospective study, pediatric intensive care in a tertiary hospital. Duration: June 2013-June 2014. Patients: Patients were included if they needed invasive mechanical ventilation for >24 h and had an indwelling arterial catheter. Patients with congenital heart disease or those who received renal replacement therapy (RRT) were excluded. Methods: Oxygenation index, fluid overload percent (daily, cumulative), RAI at admission and pediatric logistic organ dysfunction (PELOD) score were obtained in all critically ill children. KDIGO classification was used to define AKI, using both creatinine and urine output criteria. Admission data for determination of RAI included the use of vasopressors, invasive mechanical ventilation, percent fluid overload, and change in kidney function (estimated creatinine clearance). Univariable and multivariable approaches were used to assess the relations between fluid overload, oxygenation index and clinical outcomes. An RAI cutoff >8 was used to predict AKI on day 3 of admission and mortality. Results: One hundred and two patients were recruited. Fluid overload predicted oxygenation index in all patients, independent of age, gender and PELOD score (p < 0.05). Fluid overload was associated with longer duration of ventilation (p < 0.05), controlled for age, gender, and PELOD score. Day-3 AKI rates were higher in patients with a RAI of 8 or more, and higher areas under the RAI curve had better prediction rates for Day-3 AKI. An RAI <8 had high negative predictive values (80-95%) for Day-3 AKI. RAI was better than traditional markers of pediatric severity of illness (PELOD) score for prediction of AKI on day 3. Conclusions: This study emphasizes that positive fluid balance adversely affects intensive care in critically ill children. Further, the RAI prediction model may help optimize treatment and improve clinical prediction of AKI.

Tissue Edema, Fluid Balance, and Patient Outcomes in Severe Sepsis: An Organ Systems Review

Severe sepsis and septic shock remain among the deadliest diseases managed in the intensive care unit. Fluid resuscitation has been a mainstay of early treatment, but the deleterious effects of excessive fluid administration leading to tissue edema are becoming clearer. A positive fluid balance at 72 hours is associated with significantly increased mortality, yet ongoing fluid administration beyond a durable increase in cardiac output is common. We review the pathophysiologic and clinical data showing the negative effects of edema on pulmonary, renal, central nervous, hepatic, and cardiovascular systems. We discuss data showing increased morbidity and mortality following nonjudicious fluid administration and challenge the assumption that patients who are fluid responsive are also likely to benefit from that fluid. The distinctions between fluid requirement, responsiveness, and tolerance are central to newer concepts of resuscitation. We summarize data in each organ system showing a predictable increase in morbidity and mortality with nonbeneficial fluid administration, providing a better framework for precision in volume management of the patient with severe sepsis.

Transpulmonary thermodilution: advantages and limits

Background

For complex patients in the intensive care unit or in the operating room, many questions regarding their haemodynamic management cannot be answered with simple clinical examination. In particular, arterial pressure allows only a rough estimation of cardiac output. Transpulmonary thermodilution is a technique that provides a full haemodynamic assessment through cardiac output and other indices.

Main body

Through the analysis of the thermodilution curve recorded at the tip of an arterial catheter after the injection of a cold bolus in the venous circulation, transpulmonary thermodilution intermittently measures cardiac output. This measure allows the calibration of pulse contour analysis. This provides continuous and real time monitoring of cardiac output, which is not possible with the pulmonary artery catheter. Transpulmonary thermodilution provides several variables beyond cardiac output. It estimates the end-diastolic volume of the four cardiac cavities, which is a marker of cardiac preload. It provides an estimation of the systolic function of the combined ventricles. It is more direct than the pulmonary artery catheter, but does not allow the distinct estimation of right and left cardiac function. It is easier and faster to perform than echocardiography, but does not provide a full evaluation of the cardiac structure and function. Transpulmonary thermodilution has the unique advantage of being able to estimate at the bedside extravascular lung water, which quantifies the volume of pulmonary oedema, and pulmonary vascular permeability, which quantifies the degree of a pulmonary capillary leak. Both indices are helpful for guiding fluid strategy, especially in case of acute respiratory distress syndrome.

Conclusions

Transpulmonary thermodilution provides a full cardiovascular evaluation that allows one to answer many questions regarding haemodynamic management. It belongs to the category of “advanced” devices that are indicated for the most critically ill and/or complex patients.

Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016

OBJECTIVE

To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012."

DESIGN

A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. A stand-alone meeting was held for all panel members in December 2015. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development.

METHODS

The panel consisted of five sections: hemodynamics, infection, adjunctive therapies, metabolic, and ventilation. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Each subgroup generated a list of questions, searched for best available evidence, and then followed the principles of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the quality of evidence from high to very low, and to formulate recommendations as strong or weak, or best practice statement when applicable.

RESULTS

The Surviving Sepsis Guideline panel provided 93 statements on early management and resuscitation of patients with sepsis or septic shock. Overall, 32 were strong recommendations, 39 were weak recommendations, and 18 were best-practice statements. No recommendation was provided for four questions.

CONCLUSIONS

Substantial agreement exists among a large cohort of international experts regarding many strong recommendations for the best care of patients with sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for these critically ill patients with high mortality.

Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016

OBJECTIVE

To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012".

DESIGN

A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. A stand-alone meeting was held for all panel members in December 2015. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development.

METHODS

The panel consisted of five sections: hemodynamics, infection, adjunctive therapies, metabolic, and ventilation. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Each subgroup generated a list of questions, searched for best available evidence, and then followed the principles of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the quality of evidence from high to very low, and to formulate recommendations as strong or weak, or best practice statement when applicable.

RESULTS

The Surviving Sepsis Guideline panel provided 93 statements on early management and resuscitation of patients with sepsis or septic shock. Overall, 32 were strong recommendations, 39 were weak recommendations, and 18 were best-practice statements. No recommendation was provided for four questions.

CONCLUSIONS

Substantial agreement exists among a large cohort of international experts regarding many strong recommendations for the best care of patients with sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for these critically ill patients with high mortality.

The importance of albumin infusion rate for plasma volume expansion following major abdominal surgery - AIR: study protocol for a randomised controlled trial

BACKGROUND

Administration of fluids to restore normovolaemia is one of the most common therapeutic interventions performed peri-operatively and in the critically ill, but no study has evaluated the importance of infusion rate for the plasma volume-expanding effect of a resuscitation fluid. The present study is designed to test the hypothesis that a slow infusion of resuscitation fluid results in better plasma volume expansion than a rapid infusion.

METHODS/DESIGN

The study is a single-centre, assessor-blinded, parallel-group, randomised prospective study. Patients over 40 years of age admitted to the post-operative care unit after a Whipple procedure or major gynaecological surgery and presenting with signs of hypovolaemia are eligible for inclusion. Patients are randomised in a 1:1 fashion with no stratification to either rapid (30 minutes) or slow (180 minutes) infusion of 5% albumin at a dose of 10 ml/kg ideal body weight. Plasma volume is measured using 125I human serum albumin at baseline (prior to albumin infusion) as well as at 30 minutes and 180 minutes after infusion start. The primary endpoint is change in plasma volume from baseline to 180 minutes after the start of 5% albumin infusion. Secondary endpoints include the integral of plasma volume over time from baseline to 180 minutes after the start of the infusion and transcapillary escape rate of albumin (%/h) from 180 minutes to 240 minutes after the start of albumin infusion. In addition, diuresis, change in central venous oxygen saturation, lactate and blood pressure will be evaluated. A total of 70 patients will be included in the study, and the study has 80% power to detect a difference of 4 ml/kg in plasma volume expansion between the two groups.

DISCUSSION

The present study is the first clinical investigation of the importance of infusion rate for the plasma volume-expanding effect of a resuscitation fluid.

TRIAL REGISTRATION

EudraCT identifier: 2013-004446-42 . Registration date: 20 December 2013. ClinicalTrials.gov identifier: NCT02728921 . Registration date: 31 March 2016.

Effects of Early Continuous Venovenous Hemofiltration on E-Selectin, Hemodynamic Stability, and Ventilatory Function in Patients with Septic-Shock-Induced Acute Respiratory Distress Syndrome

Objective. To investigate the effects of 72-hour early-initiated continuous venovenous hemofiltration (ECVVH) treatment in patients with septic-shock-induced acute respiratory distress syndrome (ARDS) (not acute kidney injury, AKI) with regard to serum E-selectin and measurements of lung function and hemodynamic stability. Methods. This prospective nonblinded single institutional randomized study involved 51 patients who were randomly assigned to receive or not receive ECVVH, an ECVVH group (n = 24) and a non-ECVVH group (n = 27). Besides standard therapies, patients in ECVVH group underwent CVVH for 72 h. Results. At 0 and 24 h after initiation of treatment, arterial partial pressure of oxygen/fraction of inspired oxygen (PaO₂/FiO₂) ratio, extravascular lung water index (EVLWI), and E-selectin level were not significantly different between groups (all P > 0.05). Compared to non-ECVVH group, PaO₂/FiO₂ is significantly higher and EVLWI and E-selectin level are significantly lower in ECVVH group (all P < 0.05) at 48 h and 72 h after initiation of treatment. The lengths of mechanical ventilation and stay in intensive care unit (ICU) were shorter in ECVVH group (all P < 0.05), but there was no difference in 28-day mortality between two groups. Conclusions. In patients with septic-shock-induced ARDS (not AKI), treatment with ECVVH in addition to standard therapies improves endothelial function, lung function, and hemodynamic stability and reduces the lengths of mechanical ventilation and stay in ICU.

Conservative fluid management or deresuscitation for patients with sepsis or acute respiratory distress syndrome following the resuscitation phase of critical illness: a systematic review and meta-analysis

BACKGROUND

It is unknown whether a conservative approach to fluid administration or deresuscitation (active removal of fluid using diuretics or renal replacement therapy) is beneficial following haemodynamic stabilisation of critically ill patients.

PURPOSE

To evaluate the efficacy and safety of conservative or deresuscitative fluid strategies in adults and children with acute respiratory distress syndrome (ARDS), sepsis or systemic inflammatory response syndrome (SIRS) in the post-resuscitation phase of critical illness.

METHODS

We searched Medline, EMBASE and the Cochrane central register of controlled trials from 1980 to June 2016, and manually reviewed relevant conference proceedings from 2009 to the present. Two reviewers independently assessed search results for inclusion and undertook data extraction and quality appraisal. We included randomised trials comparing fluid regimens with differing fluid balances between groups, and observational studies investigating the relationship between fluid balance and clinical outcomes.

RESULTS

 = 75 %) compared with a liberal strategy or standard care.

CONCLUSIONS

In adults and children with ARDS, sepsis or SIRS, a conservative or deresuscitative fluid strategy results in an increased number of ventilator-free days and a decreased length of ICU stay compared with a liberal strategy or standard care. The effect on mortality remains uncertain. Large randomised trials are needed to determine optimal fluid strategies in critical illness.

Trauma and acute lung injury

Acute lung injury is a serious complication of major trauma occurring as a direct consequence of trauma to the lung or, more commonly, arising indirectly as a consequence of trauma elsewhere to the body. A spectrum of severity exists with acute respiratory distress syndrome (ARDS) defined as the most severe form of injury. The frequency of ARDS with severe trauma is unclear but is believed to occur in approximately 15- 25% of cases, although this is confused by the effects of multiple transfusions and associated injuries including burns and head injury. ARDS from all causes is estimated to occur with a frequency of two to 10 cases per 100 000 population. It causes a huge social and financial impact, with many survivors requiring a prolonged critical care stay and a significant number having a persisting poor quality of life a year after the injury. The mortality is, however, decreasing and stands at approximately 40%. A number of approaches are now recognized that can improve oxygenation and large trials have identified best critical care practice, leading to a reduction in ventilator-induced injury, with associated improvements in outcome.

Impact of Initial Central Venous Pressure on Outcomes of Conservative Versus Liberal Fluid Management in Acute Respiratory Distress Syndrome

OBJECTIVES

In acute respiratory distress syndrome, conservative fluid management increases ventilator-free days without affecting mortality. Response to fluid management may differ based on patients' initial central venous pressure. We hypothesized that initial central venous pressure would modify the effect of fluid management on outcomes.

DESIGN

Retrospective analysis of the Fluid and Catheter Treatment Trial, a multicenter randomized trial comparing conservative with liberal fluid management in acute respiratory distress syndrome. We examined the relationship between initial central venous pressure, fluid strategy, and 60-day mortality in univariate and multivariable analysis.

SETTING

Twenty acute care hospitals.

PATIENTS

Nine hundred thirty-four ventilated acute respiratory distress syndrome patients with a central venous pressure available at enrollment, 609 without baseline shock (for whom fluid balance was managed by the study protocol).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among patients without baseline shock, those with initial central venous pressure greater than 8 mm Hg experienced similar mortality with conservative and liberal fluid management (18% vs 18%; p = 0.928), whereas those with central venous pressure of 8 mm Hg or less experienced lower mortality with a conservative strategy (17% vs 36%; p = 0.005). Multivariable analysis demonstrated an interaction between initial central venous pressure and the effect of fluid strategy on mortality (p = 0.031). At higher initial central venous pressures, the difference in treatment between arms was predominantly furosemide administration, which was not associated with mortality (p = 0.122). At lower initial central venous pressures, the difference between arms was predominantly fluid administration, with additional fluid associated with increased mortality (p = 0.013).

CONCLUSIONS

Conservative fluid management decreases mortality for acute respiratory distress syndrome patients with a low initial central venous pressure. In this population, the administration of IV fluids seems to increase mortality.

Online Hemoglobin and Oxygen Saturation Sensing During Continuous Renal Replacement Therapy with Regional Citrate Anticoagulation

Optical hemoglobin and oxygen saturation sensor (OHOS) monitor when used in combination with other hemodynamic tools may be useful for continuous hemodynamic monitoring during ultrafiltration. The stand-alone OHOS monitor can easily be deployed predialyzer into the extracorporeal circuit of continuous renal replacement therapy (CRRT) systems. To maximize the accuracy of the OHOS in 24 hr CRRT systems, clotting in the optical blood chamber and the presensor dilution incurred by replacement fluid should be minimized. Sustained low-efficiency dialysis (SLED) with regional citrate anticoagulation is a therapy that incorporates an OHOS and maintains the overall reliability of hemoglobin (Hb) and saturation sensing. The system operates at a blood flow rate of 60 ml/min and a fixed acid citrate infusion rate of 150 ml/hr. The presensor dilution incurred by concentrated citrate infusion would result in a minimal Hb dilution (<0.7 g/dl) while minimizing optical blood chamber clotting during 24 hr SLED.

Targeted Fluid Minimization Following Initial Resuscitation in Septic Shock: A Pilot Study

BACKGROUND

IV fluid represents a basic therapeutic intervention for septic shock. Unfortunately, the optimal administration of IV fluid to maximize patient outcomes and prevent complications is largely unknown.

METHODS

Patients with septic shock admitted to the medical ICUs of Barnes-Jewish Hospital (January to December 2014) requiring vasoactive agents for at least 12 h following initial fluid resuscitation were randomized to usual care or to targeted fluid minimization (TFM) guided by daily assessments of fluid responsiveness.

RESULTS

Eighty-two patients were enrolled, 41 to usual care and 41 to TFM. For patients randomized to TFM, the net median (interquartile range) fluid balance was less at the end of day 3 (1,952 mL [48-5,003 mL] vs 3,124 mL [767-10,103 mL], P = .20) and at the end of day 5 (2,641 mL [-1,837 to 5,075 mL] vs 3,616 mL [ -1,513 mL to 9,746 mL], P = .40). TFM appeared to be safe, as indicated by similar clinical outcomes including in-hospital mortality (56.1% vs 48.8%, P = .51), ventilator days (8.0 days [3.25-15.25 days] vs 5.0 days [3.0-9.0 days], P = .30), renal replacement therapy (41.5% vs 39.0%, P = .82), and vasopressor days (4.0 days [2.0-8.0 days] vs 4.0 days [2.0-6.0 days], P = .84).

CONCLUSIONS

This pilot study suggests that TFM in patients with septic shock can be performed using protocol-guided assessments of fluid responsiveness. Larger trials of TFM in septic shock are needed.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT02473718; URL: www.clinicaltrials.gov.