Medication

  1. In theatres we draw up ‘strong phenyl’ which comprises 10mg phenylephrine diluted to 10 mls with saline. This is labelled with a red NDMR sticker below the pink phenylephrine sticker. 1 ml = 1mg of this mixture is then diluted into another 10 ml syringe and labelled to create the 100mcg/ml phenylephrine you will be familiar with. The strong phenyl is for the perfusionist to use only and kept in a safe place (in a shut cabinet in the AR then handed to the perfusionist)
  2. All CPB case must have 1000 IU/ml heparin prepared before induction of anaesthesia. This is an emergency drug and is kept on the anaesthesia trolley in the OR. The dose is 300 units per kilo meaning most adult patients require between 20 and 30 mls of heparin
  3. In CICU unfractionated heparin 5,000 IU s/c BD from day after surgery is used for DVT prophylaxis. This is due to the relatively high incidence of acute renal dysfunction after cardiac surgery making LMWH dosing less predictable
  4. All patients with IHD or post CABG surgery should be on 75mg aspirin and a statin day 1 following surgery unless contraindicated
  5. Adrenaline infusions are made up as 1mg in 50 mls (rather than 5 mg in 50 mls in GICU) initially. High dose adrenaline can be detrimental to myocardial oxygen supply & demand after cardiac surgery and may put undue stress on aortic suture lines. The initial resuscitation doses of adrenaline in cardiac arrest (where other therapies like immediate resternotomy are more likely to be curative) should be reduced (100mcg aliquots). A good pdf to help learning in this area is found at this address https://bjaed.org/article/S2058-5349(17)30182-8/pdf. This is based on CALS algorithms and is subtly different to how we learn rests in general anaesthesia training
  6. Inotropes are made as per the UHS guideline printed as a glossy kept in every AR on E level. As a rule dopamine is used as the primary B agonist up to 5-7 mcg/kg/min range (beyond this there is a ceiling effect), noradrenaline (0-0.25 mcg/kg/min) when vasoconstriction is desired. The use of vasopressin and methylene blue is occasional and guidance should be taken from a senior clinician before prescribing. Beyond this milrinone is used occasionally but with caution. As an inodilator it is common to see patients started on milrinone in the OR vasodilate hours after commencement. The treatment for this is to increase the amount of vasoconstrictor not the administration of excessive volumes of crystalloid. Levosimendan for heart surgery is extraordinarily rare after various RCTs: Cheetah, Levo-CTS, Licorn… All show no benefit for levosimendan in cardiac surgery