Propofol is a commonly used intravenous anesthetic drug with the confused injection pain issue. Jalota et al. (1) reviewed several interventions to reduce pain on injection of propofol. They concluded that the two most efficacious interventions are using the antecubital vein, and pretreatment using lidocaine in conjunction with venous occlusion using a tourniquet.
The lidocaine-tourniquet method has been widely used for decades. Lidocaine is regarded as a local anesthetic and diffuses from the vascular endothelium to non-vascular nociceptors. Lidocaine blocks membrane-bound voltage-gated sodium channels thereby interrupting impulse transmission in axons. Pretreatment using lidocaine to prevent injection pain alone, however, is less efficient than the lidocaine-tourniquet method, which revealed that the application of tourniquet technique may contribute to reducing the risk of propofol injection pain.
Venous occlusion with a rubber tourniquet at the forearm may have several features. Physically, venous occlusion may cause venous diameter distension mimicking a larger vein. The increased blood volume related to venous occlusion may provide a better buffer system in contact with propofol. Subsequently, the ischemic /reperfusion conditioning by occluding and remove a rubber tourniquet in the forearm may increase expression and activation of transient receptor potential Vanilloid 4 (TRPV4) channels to induced endothelial relaxation (2). Rath et al. demonstrated the hypoxic preconditioning in restoring NO- and further improving endothelium-derived hyperpolarization (EDH)-mediated relaxation and vasodilatation through TRPV4. Thus, the ischemic/reperfusion of venous may maintain venous distention even after the remove of the tourniquet and reduce the concerned injection pain efficiently combined with lidocaine.
1. Jalota L, Kalira V, George E, Shi Y-Y, Hornuss C, et al. Prevention of pain from propofol injection: systematic review and meta- analysis. BMJ 2011; 342: d1110
2. Rath G, Saliez J, Behets G, Romero-Perez M, Leon-Gomez E, et al. Vascular hypoxic preconditioning relies on TRPV4 dependent calcium influx and proper intercellular gap junctions communication. Arteriosclerosis, Thrombosis, and Vascular Biology 2012; 32:2241–2249.
Competing interests:
No competing interests
06 July 2015
Chia-Ming Chang
Anesthesiologist
Shu-Chia Hsu
135 Nanxiao St, Changhua city, Changhua county 500, Taiwan.
Rapid Response:
The mechanism of lidocaine-tourniquet method
Propofol is a commonly used intravenous anesthetic drug with the confused injection pain issue. Jalota et al. (1) reviewed several interventions to reduce pain on injection of propofol. They concluded that the two most efficacious interventions are using the antecubital vein, and pretreatment using lidocaine in conjunction with venous occlusion using a tourniquet.
The lidocaine-tourniquet method has been widely used for decades. Lidocaine is regarded as a local anesthetic and diffuses from the vascular endothelium to non-vascular nociceptors. Lidocaine blocks membrane-bound voltage-gated sodium channels thereby interrupting impulse transmission in axons. Pretreatment using lidocaine to prevent injection pain alone, however, is less efficient than the lidocaine-tourniquet method, which revealed that the application of tourniquet technique may contribute to reducing the risk of propofol injection pain.
Venous occlusion with a rubber tourniquet at the forearm may have several features. Physically, venous occlusion may cause venous diameter distension mimicking a larger vein. The increased blood volume related to venous occlusion may provide a better buffer system in contact with propofol. Subsequently, the ischemic /reperfusion conditioning by occluding and remove a rubber tourniquet in the forearm may increase expression and activation of transient receptor potential Vanilloid 4 (TRPV4) channels to induced endothelial relaxation (2). Rath et al. demonstrated the hypoxic preconditioning in restoring NO- and further improving endothelium-derived hyperpolarization (EDH)-mediated relaxation and vasodilatation through TRPV4. Thus, the ischemic/reperfusion of venous may maintain venous distention even after the remove of the tourniquet and reduce the concerned injection pain efficiently combined with lidocaine.
1. Jalota L, Kalira V, George E, Shi Y-Y, Hornuss C, et al. Prevention of pain from propofol injection: systematic review and meta- analysis. BMJ 2011; 342: d1110
2. Rath G, Saliez J, Behets G, Romero-Perez M, Leon-Gomez E, et al. Vascular hypoxic preconditioning relies on TRPV4 dependent calcium influx and proper intercellular gap junctions communication. Arteriosclerosis, Thrombosis, and Vascular Biology 2012; 32:2241–2249.
Competing interests: No competing interests