Plasma-Lyte 148: A clinical review

Impact of balanced versus unbalanced fluid resuscitation on clinical outcomes in critically ill children: protocol for a systematic review and meta-analysis

BACKGROUND

Isotonic crystalloid fluid bolus therapy is used in critically ill children to restore or maintain hemodynamic stability. However, the ideal choice of crystalloid remains to be determined. The most easily available and most frequently used crystalloid is 0.9% saline, an unbalanced crystalloid, that has been associated with hyperchloremic metabolic acidosis and acute kidney injury (AKI). Balanced fluids such as Ringer's lactate (RL) were developed to be closer to the composition of serum. However, they are more expensive and less readily available than 0.9% saline. Few trials have found RL to be associated with more favorable outcomes, but pediatric data is limited and inconsistent. The objective of the present systematic review is to review existing literature to determine the effect of balanced versus unbalanced fluid bolus therapy on metabolic acidosis in critically ill children.

METHODS

Using the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) guidelines, we will conduct a systematic review to retrieve all controlled trials and observational studies comparing balanced and unbalanced resuscitative fluids in critically ill children from age 28 days to 18 years old in any resuscitation settings. Search strategy was developed in collaboration with an experienced clinical research librarian. The primary outcome is the incidence and/or time to resolution of metabolic acidosis. Secondary outcomes included the incidence of hyperchloremia, AKI, duration of renal replacement therapy, vasopressors, mechanical ventilation, total volume of rehydration needed per day, extracorporeal membrane oxygenation, and length of stay and mortality. Study screening, inclusion, data extraction, and assessment of risk of bias will be performed independently by two authors. We intend to perform a meta-analysis with studies that are compatible on the basis of population and outcomes.

DISCUSSION

Isotonic crystalloid fluid bolus therapy is a ubiquitous treatment in resuscitation of critically ill pediatric patients and yet there is no clear recommendation to support the choice of balanced versus unbalanced fluid. The present review will summarize current available data in the literature and assess whether recommendations can be generated regarding the choice of crystalloids or otherwise identify knowledge gaps which will open the door to a large-scale randomized controlled trial (RCT).

Effect of incubation with crystalloid solutions or medications on packed red blood cells

BACKGROUND

American Association of Blood Banks (AABB) guidelines suggest that packed red blood cells (PRBCs) be administered through a dedicated intravenous (IV) catheter. Literature supporting this broad-scope declaration are scarce. Obtaining additional IV access is painful, costly, and an infectious risk. We evaluated the effect of co-incubating PRBCs with crystalloids and medications on PRBC hemolysis, membrane deformability, and aggregation, as well as medication concentration.

METHODS

PRBCs were co-incubated 5 minutes with plasma, normal saline (NS), 5% dextrose in water (D5W), Plasmalyte, epinephrine (epi), norepinephrine (norepi), dopamine (dopa), or Propofol (prop). Samples were then assessed for hemolysis (free hemoglobin, serum potassium), membrane deformability (elongation index [EI]), aggregation (smear, critical shear stress [mPa]) and drug concentration (High Performance Liquid Chromatography/Tandem Mass Spectrometry [LCMS-MS]). Significance (p ≤ 0.05) was determined by Wilcoxon-paired comparisons or Wilcoxon/Kruskall Willis with post-hoc Dunn's test.

RESULTS

Compared to co-incubation with plasma: 1) co-incubation resulted in significantly increased hemolysis only when D5W as used (free hemoglobin, increased potassium); 2) EI trended lower when co-incubated with D5W and trended toward higher when co-incubated with prop; 3) aggregation was significantly lower when PRBCs co-incubated with NS, D5W, or Plasmalyte, and trended lower when co-incubated with epi, norepi, or dopa. Medication concentrations were between those predicted by distribution only in plasma and distribution through the entire intra- and extracellular space.

CONCLUSION

Our data suggest that 5 minutes of PRBC incubation with isotonic crystalloids or catecholamines does not deleteriously alter PRBC hemolysis, membrane deformability, or aggregation. Co-incubation with D5W likely increases hemolysis. Propofol may promote hemolysis.

Trends and Updates on Cardiopulmonary Bypass Setup in Pediatric Cardiac Surgery

Perfusion strategies for cardiopulmonary bypass have direct consequences on pediatric cardiac surgery outcomes. However, inconsistent study results and a lack of uniform evidence-based guidelines for pediatric cardiopulmonary bypass management have led to considerable variability in perfusion practices among, and even within, institutions. Important aspects of cardiopulmonary bypass that can be optimized to improve clinical outcomes of pediatric patients undergoing cardiac surgery include extracorporeal circuit components, priming solutions, and additives. This review summarizes the current literature on circuit components and priming solution composition with an emphasis on crystalloid, colloid, and blood-based primes, as well as mannitol, bicarbonate, and calcium.

The effects of Plasma-Lyte 148 solution on blood coagulation: an in-vitro, volunteer study using rotational thromboelastometry

The current study aimed to measure the effects of Plasma-Lyte 148 solution on the blood coagulation profile according to the hemodilution level using rotational thromboelastometry (ROTEM) tests. Venous blood was collected from 12 healthy volunteers and divided into four specimen bottles, which were diluted at different levels with Plasma-Lyte 148 (0, 20, 40, and 60%). Following this, ROTEM tests were performed on the study samples. We found that as the hemodilution level increased, the ROTEM values showed a hypocoagulable pattern. The change rate of the maximum clot firmness (MCF) of INTEM was greater in the 40 (P = 0.015) and 60% (P < 0.001) dilutions than it was in the 20% dilution. Greater lengthening of the clot formation time of EXTEM was observed in the 60% dilution than it was in the 20% dilution (P < 0.001). The alpha-angle of EXTEM showed a greater decrease in the 60% dilution than it did in the 20% dilution (P < 0.001). A larger change rate of the MCF of EXTEM was observed in the 40 (P = 0.003) and 60% (P < 0.001) dilutions than it was in the 20% dilution. A greater decrease in the MCF of FIBTEM was identified in the 40 (P = 0.009) and 60% (P < 0.001) dilutions than in the 20% dilution. All coagulation pathways exhibited hypocoagulable patterns as the hemodilution level increased. However, most of the mean values of ROTEM parameters were within the normal reference range, except for those of the 60% dilution.

Normal saline versus Normosol™-R in sepsis resuscitation: A retrospective cohort study

Objective

To determine the effect of Normosol™-R as compared to normal saline on the outcomes of acute kidney injury and the need for renal replacement therapy in the resuscitation phase of sepsis.

Design

Our study is a retrospective before-and-after cohort study.

Setting

The study occurred at a 700-bed tertiary academic level 1-trauma center.

Patients

A total of 1218 patients were enrolled through emergency department admissions. The normal saline (before) cohort was defined as the dates between 1 March and 30 September 2014 and the Normosol™-R (after) cohort was assessed from 1 March to 30 September 2015.

Interventions

None.

Measurements and main results

Intravenous fluid volumes received during the first 24 h, 72 h, and total hospital stays were compared. Sodium, chloride, potassium, and bicarbonate levels at 72 h were also compared. The medical coded diagnosis of acute kidney failure, need for renal replacement therapy, hospital LOS, ICU admission, ICU LOS, in-hospital mortality, and need for mechanical ventilation were all compared. There was no significant difference in intravenous fluid volumes between groups. Regression modelling controlling for baseline characteristics and 24-h fluid intake volume found no differences between groups for the primary outcomes of acute kidney injury (P = 0.99) and renal replacement therapy (P = 0.88). Patients in the Normosol™-R cohort were found to have a lower rate of hyperchloremia at 72 h post-admission (28% vs. 13%, P < 0.0001). There was a trend toward a decrease in the hospital and ICU LOS in the Normosol™-R cohort; however, the data were not statistically significant.

Conclusions

This study was unable to detect any difference in outcomes between sepsis patients who received intravenous fluid resuscitation with either a balanced crystalloid (Normosol™-R) or normal saline, except for a decreased rate of hyperchloremia.