Ketamine is a non-competitive antagonist of N-methyl-D-aspartate (NMDA) receptors and also binds to mu and kappa opioid receptors. It is licensed as an anaesthetic agent for diagnostic and surgical procedures and is best suited to shorter procedures. It has a role in the ICU as a co-analgesic, with opioid-sparing properties. It has good analgesic properties in subanaesthetic doses. Use of midazolam or another benzodiazepine as an adjunct to ketamine reduces the incidence of emergence reactions.

Octreotide is an analogue of somatostatin. It is used to provide relief from symptoms associated with carcinoid tumours and acromegaly. It may also be used for the prevention of complications following pancreatic surgery. For patients undergoing pancreatic surgery, the peri- and post-operative administration of octreotide reduces the incidence of typical post-operative complications (e.g. pancreatic fistula, abscess and subsequent sepsis, post-operative acute pancreatitis). Octreotide exerts an inhibiting effect on gallbladder motility, bile acid secretion and bile flow, and there is an acknowledged association with the development of gallstones in prolonged usage.

Enoxaparin is a widely used LMWH, similar to dalteparin but in comparison it has a longer half-life (7 hours versus 3–4 hours, respectively).

Acetazolamide is a carbonic anhydrase inhibitor normally used to reduce intraocular pressure in glaucoma. Metabolic alkalosis may be partially corrected by the use of acetazolamide. The most common cause of metabolic alkalosis on the ICU is usually the result of furosemide administration.

Labetalol is a combined alpha- and beta-adrenoceptor antagonist. The proportion of beta blockade to alpha blockade when given orally is 3:1, and 7:1 when given IV. It lowers the blood pressure by blocking alpha adrenoceptors in arterioles and thereby reduces the peripheral resistance. Concurrent beta blockade protects the heart from reflex sympathetic drive, normally induced by peripheral vasodilatation.

Ramipril is an ACE-I; ACE-Is have a beneficial role in all grades of heart failure, usually combined with a beta blocker and diuretics. Potassium-sparing diuretics (e.g. spironolactone) should be discontinued before starting an ACE-I because of the risk of hyperkalaemia. However, low-dose spironolactone may also be beneficial in severe heart failure, and, when used together with an ACE-I, serum potassium needs to be monitored closely.

Intravenous calcium replacement is available in two forms, gluconate and chloride. The main difference between the salts is that calcium chloride contains three times more calcium than gluconate on a mmol basis per ml. Specifically, 10 ml of calcium gluconate 10% contains 2.3 mmol of calcium, whereas 10 ml of calcium chloride 10% contains 6.8 mmol. Confusion between these salts can cause harm!

Human normal immunoglobulin is prepared by cold alcohol fractionation of pooled plasma from over 1,000 donations. Individual donor units of plasma are screened for hepatitis B surface antigen (HBsAg) and for the presence of antibodies to human immunodeficiency virus type 1 (HIV-1), HIV-2 or hepatitis C virus (HCV), which, combined with careful donor selection, minimizes the risk of viral transmission. In addition, the testing for HBsAg, HIV-1, HIV-2 and HCV antibodies is repeated on the plasma pools.

Ganciclovir is related to aciclovir but is more active against CMV. It is also more toxic. It causes profound myelosuppression when given with zidovudine; the two should not be given together, particularly during initial ganciclovir therapy.