paediatric patient

• Learning Outcomes


  Interpret and analyse service users physiological measurements during anaesthesia, surgical procedures, and PACU and evaluate required interventions to ensure safe patient care
• Learning Objectives


  • Gain a basic understanding of the main differences of the paediatric anatomy and physiology
  • Give an over view of the some of equipment required for the paediatric patient requiring anaesthesia
  • Provide a brief introduction to paediatric drug calculations
• Group work


  1. Split into groups of 6

  2. Research the main anatomical and physiological difference in paediatric patients

  3. One member of the group will then feedback to the rest of the class
• Paediatrics are not small adults!
• Paediatric Anatomy and Physiology - Airway

  • Large head, short neck and prominent occiput
  • Tongue is relatively large
  • Larynx is high and anterior – C3-C4
  • Epiglottis is long, stiff and U-shaped; it flops posteriorly
  • Neonate (up to age around 6 month) preferential nasal breather
  • Airway is funnel shaped and narrowest at level of cricoid cartilage
• Paediatric Anatomy and Physiology - Breathing


  • Horizontal rib prevents increasing tidal volume
  • Bulky abdominal organs or stomach filled with gases from poor BVM cause diaphragmatic splinting
  • Chest wall is significantly more compliant than that of an adult – therefore functional residual capacity (FRC) is low
  • MV is rate dependent
  • Muscles of ventilation fatigue easily
  • Physiological dead space = 30% and increased by anaesthetic equipment
• Paediatric Anatomy and Physiology - Circulation


  • Myocardium is less contractile in neonates = ventricles less compliant = limits the size of stroke volume. Therefore CO is rate dependent
  • Vagal parasympathetic tone is most dominant – this make infant/child prone bradycardias
  • Bradycardia is associated with reduced CO
  • Bradycardia associated with hypoxia should be treated with oxygen and ventilation initially
  • Cardiac output 300-400 ml/kg and 200 ml/kg within few months
  • Sinus arrhythmias is common in children, all other irregular rhythms are abnormal
  • Tubular function is immature until 8 months therefore infants are unable to excrete large volumes of sodium
  • Urine output 1-2 ml/kg
• Paediatric Anatomy and Physiology - Disability


  • Hypoglycaemia is common in the stressed neonate and glucose levels should be monitored regularly
  • Glycogen stores are located in the liver and myocardium
  • Neurological damage may result from hypoglycaemia
  • Physiological responses to pain are similar to those seen in adults
  • Blood brain barrier is poorly formed. Drugs such as barbiturates, opioids etc. cross the barrier more readily and so a prolonged response maybe seen
• Paediatric Anatomy and Physiology - Exposure


  • Temperature control; infants have a large surface area to weight ratio with minimal subcutaneous fat
  • Poorly developed shivering, sweating and vasoconstriction mechanisms
  • Heat loss during anaesthesia is mostly via radiation but may also be lost by conduction, convection, and evaporation
  • Optimal ambient temperature to prevent loss is 34°C for premature; 32°C for neonates; 28°C in adolescents
  • Low body temperature causes respiratory depression, acidosis, decreased CO and increases the duration of action of drugs, decreases platelets function and increases risk of infection
• Paediatric drug calculations


  • Based on the weight of the child
  • The most accurate way to determine drug doses is to use an online calculator
• Example - 6 year old


  • Weight (age + 4) x 2 = 20 kg
  • Energy (4j/kg) = 80 Joules
  • Tube (age/4 + 4) = 5.5 (5.0 and 6.0)
  • Fluid (10 ml/kg) = 200 ml
  • Lorazaepam (0.1 mg/kg) = 2 mg
  • Adrenaline (0.1 ml/kg) = 2 ml
  • Glucose (2 ml/kg) = 40 ml
• Paediatric anaesthesia


  • Neonates (First 28 days of life (from due date))
  • Infants (1 month to 1 year of life)
  • Child (1 year to the onset of puberty)
  • Adult (Puberty onwards)
• Ayres – T – Piece with a Jackson Rees Modification

  Paediatric anaesthesia circuit
• Water's Circuit with a 1 litre bag

  Paediatric anaesthesia circuit
• Paed Vent tubing


  Paediatric anaesthesia circuit
• LMAs and iGels


  Sized based on the same principles as with adults
• ET Tube Sizes - Internal diameter


  Age/4 + 4.5
• ET Tube Sizes - Tube length oral


  Age/2 + 12
• ET Tube Sizes - Tube length Nasal


  Age/2 + 15
• Cuffed vs uncuffed ET tubes


  Historically paediatrics were intubated using an uncuffed tube, this is mainly to avoid mucosal damaged caused by the cuff. However, the use of cuffed tubes is becoming increasingly common practice. This is due to the improvement in tube design and the ability to monitor cuff pressures. The advantages of using cuffed tubes is that it provides an airtight seal to protect the lungs. Generally if a cuffed tube is used then when calculating the tube size, you would reduces this by 0.5cm
• Intubation Equipment


  • Stylet
  • Paed bougie
  • HME filter
  • Paed Magills
  • Paed Yanker sucker
  • Paed larynscope handle and blades
  • Paed OPA
  • Paed BP cuff
  • Paed SpO2 sensor
• Everything we do in relation to paediatric patients is based on weight ensure if you have not got an accurate rate you estimate it
• When undertaking paediatric anaesthetics there is no such thing as too much equipment