Paediatrics


Paediatrics


Tobias Hunt


Outline





Initial Assessment




Breathing



‘RR 70/min, oxygen saturations are 90%, with intercostal recession, tracheal tug, nasal flaring, and abdominal breathing. Crackles are heard throughout the lung fields bilaterally, with occasional wheeze, and reduced air entry at the lung bases. Mum is breast-feeding, and normally feeds for 15 minutes every 3 hours, but today has only managed to feed for 5 minutes in 6 hours.’



Don’t forget that crepitations could be a sign of heart failure. image


Given the above, you give supplementary nasal cannulae oxygen (since saturations are below 94%), and you prescribe a hypertonic sodium chloride nebulizer. A trial of salbutamol may be considered in older babies but this should not be continued if the initial trial is ineffective.



We had an un-immunized patient present to A&E that was treated as a presumed bronchiolitis. They had a significant cough, and started developing apnoeas. However, the blood results showed significant lymphocytosis. This was then recognized as a case of pertussis, and confirmed on pernasal swab. The lymphocyte count is an important clue to this diagnosis. image




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Figure 9.1



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Figure 9.2



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Figure 9.3






Initial Investigations



ent Capillary blood gas: An acute respiratory acidosis is indicated by a low pH, a raised PaCO2, and a normal bicarbonate/base excess. A raised lactate or a reduction in the base excess indicates a metabolic acidosis, possibly secondary to infection or hypoperfusion. Note: PaO2 is of little use on a capillary gas


ent Bloods: FBC, U&Es, CRP. Look for evidence of infection, assess renal function and hydration status


ent Nasopharyngeal aspirate (or combined nose and throat swabs): Used to detect respiratory syncytial virus (RSV), a common cause of bronchiolitis. A patient with confirmed RSV should be isolated in a side room


ent CXR: Will potentially show patchy changes consistent with bronchiolitis or pneumonia (though these are difficult to differentiate radiologically). Other respiratory pathology such as pneumothorax can be ruled out. The cardiac shadow may be suggestive of congenital heart disease (such as cardiomegaly or a boot-shaped heart in tetralogy of Fallot), which is an important differential. A CXR is not always required and is best reserved for severe cases or if the diagnosis is in doubt


ent Weight: Important for fluid calculations


‘Capillary blood gas shows a respiratory acidosis, with no metabolic compensation. pH 7.28, PaCO2of 7.5 kPa, HCO322 mmol/L, BE−0.5 mmol/L. Hb is 145 g/L, WCC 15×109/L, neutrophils 8×109/L, lymphocytes 4.5×109/L. Na 131 mmol/L, urea 9.3 mmol/L, creatinine 45 µmol/L. CRP is 20 mg/L. NPA is positive for RSV. CXR shows diffuse patchy changes in both lung fields. Weight is 6 kg.’




Initial Management [1]



ent Airway support: No airway intervention is required in this case. Indications for intubation include frequent apnoeas/cyanotic spells, or worsening on optimal supportive treatment


ent Supplementary oxygen: If saturations<94%


ent Hypertonic sodium chloride: 4 mL 3% sodium chloride can be given through a nebulizer if the child has ongoing respiratory distress. This helps loosen and mobilize thick secretions and relieves mucus plugging. It can cause bronchospasm and is therefore occasionally given immediately after a bronchodilator


ent Ipratropium bromide and/or salbutamol: Some babies may respond to bronchodilator therapy, but generally speaking, those under 12 months are unlikely to show improvement. This is because the underlying pathophysiology is of small airway obstruction secondary to inflammation and secretions rather than bronchospasm, and as such is not reversible


ent Fluid support: This baby required a fluid bolus as she was significantly dehydrated. Moderate to severe respiratory distress will impair normal feeding. Depending on the degree of respiratory distress, feeding support may take one of two forms. Nasogastric feeds allow milk to be put in the stomach with less interruption in breathing than breast or bottle feeds. Smaller feed volumes can be given to minimize gastric distension by increasing feed frequency; ensuring total daily volume is the same. If the baby is too unwell to tolerate NG feeds, IV fluids can be given


ent Feed requirements would need to be calculated based on weight. For a weight of 6 kg, 600 mL/day is required for maintenance fluid (6×100 mL/kg/day). Syndrome of inappropriate antidiuretic hormone (SiADH) may develop in children with acute respiratory problems, indicated by low serum sodium as in this case. Giving full maintenance fluids may cause the sodium to fall dangerously. Therefore, two-thirds maintenance fluid of 0.9% NaCl with 5% glucose would be given rather than full maintenance fluid:



Two-thirds maintenance of 600 mL=400 mL/24 h, prescribed as 16.7 mL/h.





Station 9.2: Respiratory distress in the newborn


You are a junior doctor working on a postnatal ward. You are called to assess a baby (male infant Jones) who is 12 hours old with a rapid respiratory rate. He was born by emergency C-section for failure to progress. Mum had antibiotics during labour due to fever. The baby was born in good condition, with no resuscitation required.







Initial Assessment








Initial Investigations



ent Capillary blood gas: An acute respiratory acidosis is indicated by a low pH, a raised PaCO2, and a normal bicarbonate/base excess. A raised lactate and/or reduced base excess indicates a metabolic acidosis, which may be secondary to sepsis or reduced perfusion


ent Bloods: FBC, U&Es, CRP and blood culture, looking for evidence of infection. The blood culture should be taken before starting antibiotics. Neonatal jaundice may be more pronounced in unwell newborns so a baseline serum bilirubin (SBR) should be taken. Group and save is normally taken early, so as to minimize delays should this baby develop sepsis and require transfusion of packed red cells or platelets


ent CXR: May show focal consolidation due to congenital pneumonia (secondary to maternal chorioamnionitis). Patchy shadowing with evidence of air trapping may indicate meconium aspiration. Hyperexpansion with a ground glass appearance is typical of surfactant deficiency (respiratory distress syndrome), while plethoric lung fields with cardiomegaly may be due to underlying congenital heart disease. Spontaneous pneumothorax should be excluded


ent Weight: Important for drug and fluid calculations. This should also be plotted on a newborn growth chart. Note: prematurity should be taken into consideration when plotting weights


‘Capillary blood gas shows a pH 7.22, PaCO2 of 8.2 kPa, HCO318 mmol/L, BE−4 mmol/L. Hb is 190 g/L, WCC 36×109/L, neutrophils 22×109/L. CRP is 75 mg/L. Bilirubin is 95 mg/dL, which plots below the threshold for phototherapy. CXR shows lobar left-sided consolidation consistent with congenital pneumonia. The weight is 3.5 kg, which plots on the fiftieth centile.’





Initial Management [2]



ent Supplementary oxygen: If saturations<94%. The child will be kept in an incubator to keep him warm while wearing a nappy only. This allows his work of breathing to be closely observed by all staff. He is placed prone as this reduces his work of breathing


ent Antibiotics: Broad-spectrum antibiotics are given intravenously to cover most likely pathogens. Benzylpenicillin and gentamicin is a combination favoured by many neonatal units. You may have local guidelines for this


ent Gentamicin requires regular monitoring of trough levels to avoid dose-dependent toxicity such as renal impairment (temporary) and ototoxicity causing sensorineural hearing loss (permanent). Trough levels are usually taken before the third dose


ent Positive blood cultures with sensitivities may allow more focused therapy depending on the organism


ent Glucose bolus: This is given quickly as a 2.5 mL/kg bolus of 10% glucose. The sugar must be reassessed within 30 minutes in case a further bolus is required


ent Fluid support: As the baby has significantly increased work of breathing, even nasogastric feeding is contraindicated as a stomach full of milk will splint the diaphragm


ent IV fluids in neonates are given as 10% glucose to prevent hypoglycaemia, as newborns have a higher glucose requirement than children. The sugar will need to be monitored regularly


ent In the first few days until physiological diuresis occurs, electrolytes such as Na+ and K+ are not required


ent Hourly fluid infusion rate is calculated as weight×60 mL/24 hours
3.5 kg×60 mL/kg/24 hours=8.8 mL/h


ent Vitamin K: All newborns are given IM vitamin K at birth to prevent haemorrhagic disease of the newborn, which can otherwise present with significant and potentially catastrophic bleeding in the first few months of life


ent Lumbar puncture: In babies where there is clinical suspicion of meningitis, or the CRP is significantly raised (threshholds will vary between units, but>10–20 mg/L is typical) a lumbar puncture should be considered.








Initial Assessment





Nov 18, 2017 | Posted by in PHARMACY | Comments Off on Paediatrics
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