Procedurer What determines a lumbar puncture is rarely the needle itself. It is the decision whether to perform it now or after imaging, how the…

…is decided before the needle goes in: the choice of site, the use of ultrasound throughout the puncture, and maintaining maximal barrier precautions without shortcuts…

…Otherwise: Type Contraindication : : Absolute No safe pocket of fluid to puncture (no ultrasound verified fluid) Relative Uncorrected coagulopathy or thrombocytopenia Relative Ongoing anticoagulant treatment — plan…

…that clots before the smears are made is unusable, no matter how well the puncture went. Indications Unexplained cytopenia in one or more cell lines…

…osteoarthritis related joint disease. Contraindications Infection of the skin or soft tissues over the puncture site — use another approach or refrain. Bacteraemia without suspicion of…

…abdominal wall collaterals (caput medusae) Puncture at least a few centimetres away from them Full bladder Have the patient void, or catheterise, before puncture Pregnancy…

…analysers — check locally. Contraindications Peripheral venous cannula: Infection, burns or trauma at the puncture site. An arm with an arteriovenous fistula, previous axillary clearance or…

…debridement because of the cosmesis, often with antibiotic prophylaxis. Deep puncture wounds , where the base cannot be inspected or irrigated clean. Wounds with retained foreign…

…a smaller size in children. A set with an integrated guidewire (Seldinger technique) helps when the vessel is difficult to puncture. Sterile preparation with chlorhexidine…

…it. A small (under 10 mm), loculated or purely posterior effusion with no safe route for puncture — surgical drainage or pericardiotomy instead. Relative: uncorrected coagulopathy…