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Fluids and Electrolyte Therapy in the Paediatric Surgical Patient 27
Table 5.5: Composition of intravenous crystalloid solutions.

K + Lactate
–
+
Solution Glucose (g/l) Na (mEq/l) Cl (mEq/l) Ca (mEq/l) pH Osm
+2
(mEq/l) (mEq/l)
5% dextrose 50 – – – – – 4.5 253
Ringer’s – 147 4 155 – 4 6.0 309

Lactated Ringer’s – 130 4 109 28 3 6.3 273

D lactated Ringer’s 50 130 4 109 28 3 4.9 525
5

D 0.22% NSS* 50 38.5 – 38.5 – – 4.4 330
5

D 0.45% NSS* 50 77 – 77 – – 4.4 407
5
0.9% NSS* – 154 – 154 – – 5.6 308

Note: NSS = normal saline solution
If the blood loss is above the allowable blood loss based upon the
Table 5.6: Intraoperative fluid requirements. starting haemoglobin, then fresh whole blood is the most commonly
transfused component in Africa. The development of a “walking blood
1. Estimated 0–10 kg = 4 ml/kg/hr +
fluid requirement 10–20 kg = 2 ml/kg/hr + bank” should be an aspect of each hospital involved in operative
(EFR) per hour >20 kg = 1 ml/kg/hr procedures. This would entail a group of donors known by the hospital
(maintenance (e.g., 23-kg child = 40 ml + 20 ml + 3 ml, so EFR= 63 lab who can donate blood for emergencies; the opportunity to use
fluids) ml/hr)
warm, fresh (nonstored) blood in the paediatric surgical patient can be
life-saving. The inability to adequately warm stored blood is always
an issue when a neonate is requiring blood in surgery. If stored (cold)
2. Estimated EFD = Number of hours NPO × weight (in kg)
preoperative fluid (e.g., 23-kg child NPO for 8 hours blood is required, a warm bath of water with the tubing within the bath
deficit (EFD) EFD = 8 × 23 = 184 ml) is often useful to help warm the fluids. Hypothermia in a paediatric
patient can result in slow awakening and, in the extreme case, cardiac
1st hour = ½ EFD + EFR
2nd hour = ¼ EFD + EFR arrhythmias. The use of the buretrol and a three-way stopcock is the
3rd hour = ¼ EFD + EFR most useful manner to give blood in a newborn or very small paediatric
patient. A 10- or 20-ml syringe is applied to the stopcock, and the exact
amount of blood or volume of other fluid can be given, with this amount
3. Insensible Minimal incision = 3–5 ml/kg/hr accurately recorded. Blood products should be initially given in 10 ml/
losses (IL): (add Moderate incision with viscus exposure = 5–10 ml/ kg increments and as needed based upon heart rate and blood pressure;
EFR and EFD) kg/hr
Large incision with bowel exposure = 8–20 ml/kg/hr more should be added to maintain a normal intravascular blood volume.
The estimated blood volume in the paediatric patient is as follows:
Premature infant 90–100ml/kg
4. Estimated Replace maximum allowable blood loss (ABL) with
blood loss crystalloid 3:1 Full-term infant 80–90 ml/kg
3 months–1 year 75–80 ml/kg
>1 year 70–75 ml/kg
Complications that can occur in the surgical neonate or paediatric
The estimated blood loss is extremely difficult to determine in the
newborn surgical patient, and the anaesthesia care provider needs to patient in regard to fluids and electrolytes intraoperatively include fluid
calculate the estimated blood volume and allowable blood loss for overload and pulmonary oedema; hypocalcaemia with large amounts
every patient before surgery. The surgery team must closely monitor of blood transfusions; elevated potassium levels; hypothermia due to
blood loss and, with sponge observation, determine the blood loss at the infusion of cold fluids; hypotension secondary to hypovolaemia;
many points during the surgical procedure. Invasive monitoring, even and low sodium levels if D 10 is infused without the addition of any
in large surgical procedures, is rare in most areas of Africa, so the use electrolytes. It should be noted that at any sign of bradycardia in the
of noninvasive blood pressure, urine output, elevations in heart rate, and surgical neonate, one must first verify the condition of the respiratory
capillary perfusion need to provide clues to the overall fluid status of the system because bradycardia is one of the first signs of poor oxygenation.
patient during a surgical procedure. If a pulse oximeter is available, then Principles for therapy for fluid overload in the paediatric patient include
the waveform changes can help with the perfusion pulse pressure, which fluid restriction, salt restriction, diuresis or even dialysis, and albumin
4
may indicate a change in blood volume, cardiac output, or temperature. that is salt poor to help with the fluid status.