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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.
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