Paeds Flashcards
What are the upper and lower limits of BP
Lower 5th percentile
0-28 days SBP 60
1-12months SBP 70
1-10years 70 + 2(age)
95th percentile
100 + 2(Age)
Sepsis guidelines state pt is shocked when:
neonate SBP< 50
<12month old SBP<60
<5yrs SBP <70
List some differences between the pediatric and adult ariway
Airway similar to adult by 8yrs of age
1) Large head, short neck and prominent occiput
2) Relatively larger tongue - may need guidel
3) Larynx is high and anterior - may use straight blade laryngoscopy up to 1yrs of age
4) Epiglottis is longer, U shaped and floppy
(From 3 and 4 airway obstructs in sniffing position and needs to be kep neutral)
5) Airway is funnel shaped and narrowest at cricoid cartilage - cuffed tubes unnecessary and can damage delicate tracheal mucosa
6) Flexible trachea prone to collapse with cricoid pressure
7) Friable epithelium prone to bleeding and oedema
8) Shorter trachea - increased risk of bronchi intubation
9) Ventilation is primarily diaphragm dependent and limited increase to tidal volume due to horizontal posterior ribs - bulky abdominal contents can limit ventilation
10) Minute volume largely RR dependent
11) Reduced FRC
12) Less alveoli, only 10% at birth while the rest of the clusters develop in the first 8yrs of life
13) Higher O2 requirements (6ml/kg/min vs 3-4 in adults) so tolerate shorter apnea times
List some physiological differences between paed and adults (not airways or respiration)
Cardio
- Fixed stroke volume due to less compliant ventricles therefore cardiac output is rate dependent
- Vagal parasympathetic tone is most dominant and so prone to bradycardias
Renal
- Higher body water percentage at birth (80% vs 60%)
- Increased insensible losses due to larger surgace area relative to weight
- Lower renal blood flow and GF in first 2 yrs
- Tubular function immature until 8 months and so unble to excrete large sodium load
Hepatic
- Immature liver function and hepatic enzymes so longer duration of action of medications (opiods and barbiturates)
Metabolic
- Hypoglycemia is common in stressed neonate due to poor glycogen stores
- Basal metabolic rate 3-4 times greater than adults
Haem
- Larger blood volume relative to weight
- Vit K dependent factors and plt function are deficient in first few months of life
- At birth 70-90% of Hb is HbF. At 3 months drops to 5%
- Less 2-3 DPG in HbF so less likely to release O2
Temp control
- Poorly developed shivering, sweating and vasocontriction mechanism
- Larger body surface area to weight ratio
- Non shivering thermogenesis relies on brown fat which require more oxygen
CNS
- Poorly formed BBB
- Cerebral vessles are thin walled and fragile in preterm infants
What are the formulas for paediatric tube size and length
Tube size = age/4 + 4.5 uncuffed (0.5-1 size smaller for cuffed)
Tube length = age/2 +12 at the teeth OR ETTx3
NG size = ETT x2
List 10 risk factors for neonatal sepsis
Prematurity
Low birth weight
Prolonged rupture of membranes >18hrs
Maternal GBS
Exposure of HSV lesions
Poor antenatal care (?TORCH infections)
Maternal infection during labour (chrioamnionitis)
Invasive procedures
Use of prophylactic antibiotics during labour
Instrumental delivery
What microbial agents commonly cause neonatal sepsis
Early onset (<48hrs)
Group B Step
E Coli
Listeria
Late Onset (>48hrs)
Staph Epidermis and Staph aureus
EColi
Klebseilla
Enterbacter
Pseudomonas
Also consider
Herpes Simplex, enterovirus and parechovirus
Candida
What are the differentials for the unwell neonate
THE MISFITS
Trauma - birth trauma or NAI
Heart disease - hyperoxia test with preductal (RUL) ABG after several minutes of 15L NRB. If pO2 not >250 probable CHD and should have prostaglandin E1 0.05microg/kg/min. (pO2<100 extremely predictive of CHD)
Endocrine Emergencies - CAH, hypo or hyperthyroid
Metabolic - diGeorge syndrome (hypocal and seizures)
Inborn errors of metabolism - ammonia, glucose, ketones, lactate and treatment is hypercatabolic state with 10% glucose
Seizure - boxing or cycling of limbs
Formula problems - hyponat if diluted or hypovol if concentrated
Intestinal disasters - NEC, volvulus
Toxins - maternal medications or home remedies
Sepsis - emperic abx
