Ringer’s lactate is compatible with the rapid infusion of AS-3 preserved packed red blood cells

A balancing act: drifting away from the reflexive use of "ab"normal saline

Maintenance intravenous fluids are the most frequently ordered medications for hospitalized children. Since the American Association of Pediatrics published national guidelines, there has been an increased reflexive use of isotonic solutions, especially 0.9% saline, as a prophylaxis against hyponatremia. In this educational review, we discuss the potential deleterious effects of using 0.9% saline, including the development of hyperchloremia, metabolic acidosis, acute kidney injury, hyperkalemia, and a proinflammatory state. Balanced solutions with anion buffers cause relatively minimal harm when used in most children. While the literature supporting one fluid choice over the other is variable, we highlight the benefits of balanced solutions over saline and the importance of prescribing fluid therapy that is individualized for each patient.

Crystalloid and Colloid Compositions and Their Impact

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

Mixing commonly used crystalloid solutions with red blood cells in five common additives does not negatively impact hemolysis, aggregometry, or deformability

BACKGROUND

Literature is beginning to challenge the belief that it is unsafe to coinfuse red blood cells (RBCs) with solutions other than isotonic saline. We recently showed that additive-free RBCs tolerated coincubation with Plasma-Lyte or catecholamines dissolved in normal saline (NS), though 5% dextrose in water (D5W) promoted hemolysis. Herein, we evaluate the effect of coincubating crystalloids on additive-preserved RBC hemolysis, aggregation, and membrane deformability.

STUDY DESIGN AND METHODS

RBCs were coincubated 5 minutes with plasma, NS, Plasma-Lyte, lactated Ringer's (LR) or D5W (1 mL PRBC +131.3 μL solution). Samples were then assessed for hemolysis (free hemoglobin), aggregation (critical shear stress [mPa]), and membrane deformability (elongation index [EI]). Significance (P ≤ .05) by t test or ANOVA with post-hoc Tukey-Kramer test.

RESULTS

Additive-prepared RBCs coincubated with crystalloid instead of plasma demonstrated: (a) no increase in hemolysis as indicated by plasma free hemoglobin levels that is likely to be clinically relevant; (b) no increase, but in some cases a decrease, in aggregation as indicated by critical shear stress; and (c) in some combinations, a deterioration in deformability. When present, the deformability decrease was likely clinically insignificant in degree, and always returned to normal when the crystalloid was subsequently diluted out with plasma.

CONCLUSION

Our data suggest that additive-prepared RBCs coincubated for 5 minutes with any of four common crystalloids demonstrate no clinically relevant increased lysis, increased aggregation, or decreased deformability.

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.

0.9% NaCl (Normal Saline) - Perhaps not so normal after all?

Crystalloid infusion is widely employed in patient care for volume replacement and resuscitation. In the United States the crystalloid of choice is often normal saline. Surgeons and anesthesiologists have long preferred buffered solutions such as Ringer's Lactate and Plasma-Lyte A. Normal saline is the solution most widely employed in medical and pediatric care, as well as in hematology and transfusion medicine. However, there is growing concern that normal saline is more toxic than balanced, buffered crystalloids such as Plasma-Lyte and Lactated Ringer's. Normal saline is the only solution recommended for red cell washing, administration and salvage in the USA, but Plasma-Lyte A is also FDA approved for these purposes. Lactated Ringer's has been traditionally avoided in these applications due to concerns over clotting, but existing research suggests this is not likely a problem. In animal models and clinical studies in various settings, normal saline can cause metabolic acidosis, vascular and renal function changes, as well as abdominal pain in comparison with balanced crystalloids. The one extant randomized trial suggests that in very small volumes (2 l or less) normal saline is not more toxic than other crystalloids. Recent evidence suggests that normal saline causes substantially more in vitro hemolysis than Plasma-Lyte A and similar solutions during short term storage (24 hours) after washing or intraoperative salvage. There are now abundant data to raise concerns as to whether normal saline is the safest replacement solution in infusion therapy, red cell washing and salvage, apheresis and similar uses. In the USA, Plasma-Lyte A is also FDA approved for use with blood components and is likely a safer solution for these purposes. Its only disadvantage is a higher cost. Additional studies of the safety of normal saline for virtually all current clinical uses are needed. It seems likely that normal saline will eventually be abandoned in favor of safer, more physiologic crystalloid solutions in the coming years.

Association between delivery methods for red blood cell transfusion and the risk of venous thromboembolism: a longitudinal study

BACKGROUND

Mechanisms of red blood cell delivery and their contribution to the incidence of venous thromboembolism are not well understood in the clinical setting. We assessed whether red blood cell transfusion through peripherally inserted central catheters (PICCs) affects the risk of venous thromboembolism compared with transfusion through non-PICC devices.

METHODS

We implemented a prospective study between Jan 1, 2013, and Sept 12, 2015, in patients (age ≥18 years) admitted to a general medicine ward or intensive care unit who received a PICC for any reason during clinical care in 47 hospitals in Michigan, USA, with a maximum follow-up of 70 days. The exposure of interest was route of red blood cell transfusion. The primary outcome was symptomatic, radiographically confirmed, deep-vein thrombosis in the arm or leg or pulmonary embolism. We used Cox proportional hazards regression for analyses.

FINDINGS

Venous thromboembolism developed in 482 (5%) of 10 604 patients with PICCs. Of 788 patients who received a red blood cell transfusion through a multi-lumen PICC, 61 had venous thromboembolism. The adjusted hazard ratio (HR) for venous thromboembolism in all patients whose transfusions were administered through a multi-lumen PICC was 1·96 (95% CI 1·47-2·61; p<0·0001) compared with patients not receiving a transfusion, and was 1·79 (1·09-2·95; p=0·022) compared with patients transfused through a peripheral intravenous line. Compared with delivery through a peripheral intravenous line, venous thromboembolism risk was not elevated if transfusions were delivered through a single-lumen PICC (HR 0·98, 95% CI 0·44-2·14; p=0·95) or central venous catheter (1·50, 0·77-2·91; p=0·23). For every red blood cell unit transfused through a PICC, there was a significantly increased risk of venous thromboembolism (adjusted HR 1·24, 95% CI 1·01-1·52; p=0·037). Patients who received a transfusion through a PICC in the left arm were significantly more likely to develop a deep-vein thrombosis in the ipsilateral arm compared with the contralateral side (HR 23·44, 95% CI 2·96-185·83; p=0·0028). Similarly, patients transfused through a right-sided PICC were more likely to develop deep-vein thrombosis in the ipsilateral arm (HR 3·37, 95% CI 1·02-11·14; p=0·047).

INTERPRETATION

Red blood cell delivery through a multi-lumen PICC is associated with a greater risk of thrombosis than transfusion through a peripheral intravenous catheter. Careful monitoring for venous thromboembolism when transfusing red blood cells through multi-lumen PICCs seems necessary.

FUNDING

Blue Cross Blue Shield of Michigan and Blue Care Network, as part of the BCBSM Value Partnerships program.

Rational fluid management in today's ICU practice

Intravenous fluid therapy has evolved significantly over time. From the initial report of the first intravenous administration of sodium-chloride-based solution to the development of goal-directed fluid therapy using novel dynamic indices, efforts have focused on improving patient outcomes. The goal of this review is to provide a brief overview of current concepts for intravenous fluid administration in the ICU. Results of recently published clinical trials suggesting harmful effects of starch-based solutions on critically ill patients are discussed. Concepts for goal-directed fluid therapy and new modalities for the assessment of fluid status as well as for the prediction of responsiveness to different interventions will continue to emerge. Advances in technology will have to be critically evaluated for their ability to improve outcomes in different clinical scenarios.