Archive for January, 2012

Ankle Block

Posted: January 3, 2012 by gerardloh in Orthopaedics & Traumatology

An ankle block is essentially a block of the terminal branches of the sciatic nerve. It is useful to think of the ankle block as the block of

two deep nerves

1. posterior tibial and

2. deep peroneal nerves

three superficial nerves

1. saphenous

2. sural

3. superficial peroneal
This concept is crucial for the success of the block, because the two deep nerves are anesthetized by injecting local anesthetic underneath the superficial fascia, whereas the three superficial nerves are anesthetized by a simple subcutaneous injection of local anesthetic.

Deep nerves
1. Deep peroneal block

The finger of the palpating hand is positioned in the groove just lateral to the extensor hallucis longus. The needle is inserted under the skin and advanced until stopped by the bone. At this point, the needle is withdrawn back 1-2 mm and 2-3 mL of local anesthetic is injected.  A “fan” technique is recommended to increase the success rate.

2. Post tibial block

Posterior tibial nerve is anesthetized by injecting local anesthetic just behind the medial malleolus.
Facing the medial aspect of the foot, the needle is introduced in the groove behind the medial malleolus and advanced until contact with the bone is felt. At this point, the needle is withdrawn back 1-2 mm and 2-3 mL of local anesthetic is injected.

Spf nerves

1. Spf peroneal nerves

Superficial peroneal nerve is blocked by subcutaneous infiltration of local anesthetic over the lateral aspect of the foot.

2.Sural nerve


3 Saphenous nerve

Saphenous nerve is blocked by subcutaneous infiltration of local anesthetic over the medial as pect of the foot.


Respiratory Distress in Newborn

Posted: January 2, 2012 by kiamseong in Paediatrics, Uncategorized

The followings are the slides prepared by us for HO teaching presentation in HTAR, Klang. (Links for download)

Enjoy! =)

Part 1

Part 2

Part 3

Confused with different ventilators in NICU/PHDU?

Posted: January 2, 2012 by kiamseong in Paediatrics

Let’s understand the basic principal of functioning of ventilators in your NICU/PHDU.

Assist-control ventilation (Maquet ventilator/ IPPV – Drager ventilator)

  • Regardless ventilator/patient initiates breath, every breath the same (operator set tidal volume and minimal ventilator rate)
  • Ventilator just functions to compensate patient’s effort
    • Time cycled ventilator
      • Tidal volume and Resp rate set + Time set
      • Maquet (Siemen)/ Drager ventilator
    • Volume cycled ventilator
      • Tidal volume and Resp rate set + Flow set
      • Puritan-Vennett Bear ventilator
Advantage Disadvantage
  • Relative simple to set
  • Guarantee minimum ventilation


  • No synchrony between patient-ventilator, ventilator initiate come on top
  • Patient may lead ventilator
  • Inappropriate trigger è hiccough
  • Fall in lung compliance => risk of barotrauma
  • Require sedation to achieve synchrony

Pressure control ventilation

  • Time cycled assisted control ventilation in which inspiratory pressure is set instead of tidal volume
  • High initial flow => fall to zero by end of inspiration
  • Inspiratory pause is effectively built into the breath
  • Tidal volume not set if inspiratory time short then tidal volume lower

Synchronized Intermittent Mandatory Ventilation (SIMV)

  • Patient receives a set number of mandatory breaths, synchronized with any attempts by the patient to breath
  • Patient can take additional breath between mandatory breaths (pressure supported)
  • For improve patient-ventilator synchrony

Advantage Disadvantage
  • Better patient-ventilator synchrony
  • Guarantee minimum minute ventilation

Continuous Positive Airway Pressure (CPAP)

  • Constant pressure both inspiratory and expiratory phase -> splint open alveoli, therefore to decrease shunting
  • Inspiration initiate from baseline pressure and airway pressure decrease to baseline at the end of respiration
  • Patient controls rate and tidal volume himself (totally dependent on patient’s inspiration effort)
  • Allow spontaneous breathing at an elevated baseline pressure

Non-invasive PPV – without invasive artificial airway (Endotracheal tube/ETT)

  • Due to face mask seal not perfect, usually use with ventilator (BiPAP) to provide some degree of compensation for leaks around the mask
  • Require patient to be alert, cooperate, able to protect his airway, haemodynamically stable
  • Low level of support initially then gradually increase to improve patient tolerance
  • BiPAP = pressure support + PEEP
    • Inspiratory pressure = 8-10 cmH2O
    • Expiratory pressure = 4-6 cmH2O
  • Effective for patient with chronic obstructive airway diseases/ cardiogenic pulmonary oedema
  • Less effective for pneumonia/ARDS