So inhibition of COX-2 may tip the thromboxane/ prostacyclin balance in favor of vasoconstriction, platelet aggregation, and thromboembolism.

Amid reports of increased cardiac deaths many of the earlier COX-2 inhibitors have been withdrawn from the market. In the USA, celeoxib survives, whilst in Europe, parecoxib is available intravenously. Mounting concerns have placed a cloud over this whole class of drugs (Table 7.4).

7.5.8 Other Agents

Glycopyrrolate, used for its antisialogogue action, counters the increase in secretions accompanying ketamine usage. Dexamethasone has a dual role as an anti-inflammatory and antiemetic. Ondanestron a 5HT3 receptor antagonist, is a powerful antiemetic, and a crucial drug in any rescue strategy. Adrenoceptor agonists/antagonists(epinephrine,ephedrine,metaraminol, labetalol, esmolol) assist in maintaining cardiovascular stability. Rocuronium, a non-depolarizing muscle relaxant, when administered at 25% intubating dose,

enables rectus muscle repair while the patient continues to breathe spontaneously.

7.6Devices Used in the Delivery of Sedation

Currently, there is a difference as to how propofol is delivered between the USA and Europe. The USA predominantly uses manually controlled devices with or without a bolus facility whereas much of Europe has target-controlled infusion (TCI) devices. These TCI pumps deliver propofol in accordance with micropro- cessor-controlled algorithms, based on pharmacokinetic modeling, aimed at rapidly achieving and maintaining a constant drug concentration in the plasma or at the drug effect site [29]. Continuing research into effect site TCI demonstrates a faster onset and greater predictability of drug action, without adverse hemodynamic consequences [30].

Clinically, the distinction between the two infusion regimes blurs when propofol is titrated with a loss- of-consciousness monitor like BIS.