Healthcare and Medicine Reference
In-Depth Information
Insertion and collection is as described for adults in Chapter 7:
the needle will not need to be inserted as far as in adults
{
collect approximately 5-7 drops per container
{
use three universal containers for cell count, culture and protein
{
with one glucose tube.
Remove needle and cover site with plaster when fi nished.
Complications
Bleeding (mild), infection (rare).
Headache.
Suprapubic aspiration of urine
Indication
To obtain an uncontaminated urine sample.
Contraindications
Clotting disorders or thrombocytopenia.
Figure 22.9 Filled capillary gas tube. Place bungs on either end and roll the
tube between fi ngers to ensure mixing.
Procedure
Ideally confi rm that there is urine in the bladder with
ultrasound.
Use aseptic technique.
pH
(Norma Range)
7.35-7.45
Attach a blue (23G) needle to a 5-mL syringe.
Insert the needle into the abdomen 1 cm above the symphysis
pubis perpendicular to the skin.
Insert the needle to 2-3 cm, aspirating continuously until urine
pH < 7.35
pH > 7.45
Acidosis
obtained.
Remove needle and cover puncture site with a plaster.
Alkalosis
BD/-ve BE
HCO 3
HCO 3
BE
CO 2
CO 2
Complications
Bleeding.
Respiratory
acidosis
Respiratory
alkalosis
Metabolic
acidosis
Metabolic
alkalosis
An alternative sampling method is the in-out catheter. The tech-
nique is the same as for catheterisation except that the catheter is
removed once a urine sample is obtained.
Figure 22.10 Analysis of blood gases. BD, base defi cit; BE, base excess.
Blood gases
Table 22.1 Causes of blood gas abnormalities.
In paediatrics we rarely take arterial blood gases unless the patient
has an arterial line. More commonly we rely on capillary or venous
gases, collected via a capillary tube. This small glass tube is fi lled
using heel or fi nger prick (capillary) or directly from venepuncture.
The sample needs to be free fl owing without any bubbles in the
tube for accurate analysis (Figure 22.9).
Blood gases are interpreted in a similar manner to adults
(see Chapter 6). Be mindful that some of the values will not be
accurate. With venous gases, the pH and HCO 3 results are useful,
but the reliability of the PCO 2 is debatable and should be inter-
preted with caution. Capillary gases are comparable with arterial
gases for PCO 2 , pH and HCO 3 but not PO 2 . See Figure 22.10 for
an introduction to analysing blood gases. Table 22.1 gives some
causes of blood gases abnormalities.
Respiratory acidosis
Poor respiratory drive
(e.g. unconsciousness, neuromuscular disorders)
Respiratory diseases
(e.g. asthma, bronchiolitis)
Metabolic acidosis
Diabetic ketoacidosis
Poor tissue perfusion
Renal disorders
(e.g. renal tubular acidosis)
Inborn errors of metabolism
(e.g. organic acidaemias)
Respiratory alkalosis
Hyperventilation
Salicylate poisoning (can also cause metabolic acidosis)
Metabolic alkalosis
Severe vomiting
(e.g. pyloric stenosis)
Renal disorders
(e.g. Bartter's syndrome)
Further procedures
There are several other procedures that would only be expected at
a more senior level in paediatrics and neonatology. These include
Search Pocayo ::




Custom Search