Haemodynamic Effect of Intravenous Paracetamol during and after Cardiac Surgery

Intravenous paracetamol (Actavis, North Adelaide, SA) Paracetamol is one of the most commonly used medications in the world. The intravenous format is the preferred method of administration in the intraoperative and immediate postoperative periods. In 100mL of solution for infusion, intravenous paracetamol contains the following: Paracetamol = 1g Mannitol = 3.91g Cysteine hydrochloride monohydrate Dibasic dihydrate sodium phosphate Sodium hydroxide Hydrochloric acid Water for injections The insertion of a pulmonary artery catheter (PAC) is required for routine anaesthesia treatment during cardiac surgery. Haemodynamic measurements will be monitored via the PAC. After insertion of the PAC, 100mL paracetamol (containing 1g paracetamol and 3.91g mannitol) will be administered intravenously. Volume of paracetamol to be administered: Actavis (North Adelaide, SA) recommends 1g of paracetamol per administration with a maximum of 4g of paracetamol per day. The minimum dose interval is 4 hours. The duration of infusion is 15 minutes. In this trial, a 1g of paracetamol will be administered every 6 hours, for 3 consecutive doses, which is in line with the manufacturer's recommendations. The first dose will be administered on arrival to the operating room, prior to induction of anaesthesia. The second dose will be administered 6 hours after the first, which may be near completion of surgery or in the intensive care unit. The final dose will be 6 hours later in the intensive care unit. The duration of each infusion will be set at 15 minutes. Paracetamol will be administered in addition to standard care analgesia. In accordance with strict hospital protocols, all doses of paracetamol administered will be recorded or logged on the participants analgesic chart.