Central venous cannulation and pressure monitoring.

Central venous pressure (CVP) varies directly with circulating blood volume and vascular tone and inversely with right heart competency. Indications for central cannulation include cardiorespiratory arrest. The two general approaches to cannulation of central veins are peripheral and central. The physician's skill, patient's body habitus, clinical circumstances, age and thoracic deformity all influence the choice of technique. Three of the possible complications discussed are pneumothorax, arterial puncture and air embolus. Accurate measurement of CVP depends on the patient being supine, a patent and accurately located catheter and the establishment of a baseline external zero point.