Transfusions in the Critically Ill Pediatric Patient

Table 1. Suggested red blood cell transfusion thresholds for infants under 4 months of age according to The British Committee for Standards in Hematology Transfusion Task Force.
	Hemoglobin threshold
Anemia in the first 24 h of life	Hb: 12 g/dl (Hct circa: 0.36)
Cumulative blood loss in 1 week in a neonate requiring intensive care	10% blood volume
Neonate receiving intensive care	Hb: 12 g/dl
Acute blood loss	10% blood volume
Chronic oxygen dependency	Hb: 11 g/dl
Late anemia in a stable infant	Hb: 7 g/dl

Hb: Hemoglobin; Hct: Hematocrit.
Adapted from ^[16].

Box 1. Guidelines for red blood cell transfusion in patients less than 4 months of age.
Hct <20% with a low reticulocyte count and symptoms of anemia^† Hct <30% in an infant: On <35% hood O₂ On O₂ via a nasal cannula On continuous positive airway pressure and/or intermittent mandatory ventilation with mechanical ventilation with a mean airway pressure of <6 cm H₂O With significant apnea or bradycardia^‡ With significant tachycardia or tachypnea^§ With a low weight gain^¶ Hct <35% in an infant: On >35% hood O₂ On continuous positive airway pressure/intermittent mandatory ventilation with a mean airway pressure of ≥6–8 cm H₂O Hct <45% in an infant On ECMO With congenital cyanotic heart disease

^†Tachycardia, tachypnoea or poor feeding.
^‡More than six episodes in 12 h or two episodes in 24 h requiring bag and mask ventilation while receiving therapeutic doses of methylxanthines.
^§Heart rate >180 beats/min for 24 h; respiratory rate >80 breaths/min for 24 h.
^¶Gain of <10 g/day observed over 4 days while receiving ≥100 kcal/kg/day.
Hct: Hematocrit; ECMO: Extracorporeal membrane oxygenation.
Adapted from ^[18].

Box 2. Suggested hemoglobin thresholds for red blood cell transfusions in the pediatric age group.
*Infants less than 4 months of age* Hb <7 g/dl in a stable patient with late anemia Hb <8 g/dl for symptomatic anemia Hb <10 g/dl for major surgery Hb <10 g/dl in cases of moderate cardiopulmonary disease Hb <13 g/dl in cases of severe cardiopulmonary disease *Children* Hb <7 g/dl for symptomatic anemia Hb <9 g/dl in cases of cardiopulmonary disease Acute blood loss >30% of circulating blood volume

Hb: Hemoglobin.

Sidebar

Executive Summary

Anemia in critically ill children

Anemia is present in a substantial number of critically ill pediatric patients and can be correlated with poor outcomes.
The optimal hemoglobin (Hb) threshold for transfusion is unknown, as is the target Hb concentration that the pediatrician should aim to achieve.
Transfusion therapy requires vigilant attention to the unique physiological status of the pediatric patient, particularly in the neonatal period.
Children generally have a greater ability to compensate for anemia and to safely tolerate lower Hb levels than adults.

Red blood cell transfusions

Red blood cell (RBC) transfusions are a common therapy in critically ill anemic children.
There are multiple risks associated with RBC transfusions, including transfusion-transmitted infections, transfusion-related acute lung injury, hemodynamic compromise, intravascular volume overload, acute hemolysis and immunologic consequences.
Packed RBCs are the component of choice during RBC loss and sporadic transfusion therapy.
Leukoreduced and irradiated RBC products are used in all long-term transfused children, neonates, hematopoietic stem cell transplant recipients and children with immune deficiencies.

Transfusion guidelines

There are no universally accepted treatment guidelines for managing anemia in pediatric intensive care units.
The decision to transfuse must be based on an assessment of the risks of anemia versus the risks of transfusion, and Hb value should not be the sole deciding factor when considering whether to transfuse RBCs.
For critically ill stable children, a 'restrictive' strategy of RBC transfusion (Hb level: <7 g/dl) is as equally effective as a 'liberal' transfusion strategy (Hb level: <10 g/dl).

Future perspective

Pediatric transfusion medicine is evolving and incorporating new pharmacological agents into the armamentarium of anemia.
Large multicenter studies are needed to determine if a symptomatic transfusion strategy is as effective or possibly superior to a Hb-based transfusion strategy in high-risk patients in pediatric intensive care units.