Anaesthesia
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Controlled Clinical Trial
Accuracy of conventional digital palpation and ultrasound of the cricothyroid membrane in obese women in labour.
Success of cricothyroidotomy depends on accurate identification of anatomical neck landmarks. Anaesthetists palpated the cricothyroid membrane of 28 obese and 28 non-obese women in labour (cut-off BMI 30 kg.m(-2) ) and marked the entry point for device insertion with an ultraviolet invisible pen. Ultrasonography was used to mark the midpoint of the cricothyroid membrane and the distance between the two marks was measured. ⋯ Increased neck circumference in obese patients was significantly associated with inaccuracy in locating the cricothyroid membrane. Percutaneous identification of the cricothyroid membrane in obese women in labour was poor. Pre-procedural ultrasound may help improved the identification of neck landmarks for cricothyroidotomy.
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The optic nerve sheath diameter has been verified by various clinical studies as a non-invasive indicator of intracranial hypertension. The aim of this study was to compare the optic nerve sheath diameter before and immediately after ventriculo-peritoneal shunt surgery in children with hydrocephalus. ⋯ The mean (SD) optic nerve sheath diameters were 5.4 (0.6) mm (right) and 5.3 (0.7) mm (left) before surgery and 4.4 (0.5) mm (right) and 4.5 (0.7) mm (left) after surgery (p < 0.0001 for before and after comparisons for both eyes). The technique allows rapid and non-invasive assessment of intracranial pressure to guide appropriate postoperative management.