The measuring principle

Main advantages:

PAM has indices to tailor the level of analgesia during intensive care, postoperatively, and anaesthesia in all age groups as well for preterm infants from 23 weeks of gestational age (the device is not influenced from gestational and postnatal age). The technology is not influenced by temperature (22 °C – 42 °C), general hypoxia, hypo- and hyper-volume, beta-blockers, epinephrines, and the hypotensive effect of alfa-2 agonists, as well as neuromuscular blockers (neuromuscular blockers act on nicotine receptors). This is due to the fact that skin sympathetic nerves, mirrored by skin conductance changes, have acetyl-choline acting on muscarinic receptors (atropine does not influence in clinical doses).

The Skin Conductance Algesimeter therefore meets the need to tailor analgesia when medications with hypotensive and blood circulatory effect, like alfa-2 agonists and beta-blockers, are used to reduce the level of opioids.

The Physiology:

The Skin Sympathetic Nerves (assessed by micro-neurography) are the only sympathetic nerves in the body where acetylcholine acts on muscarinic receptors. How often these nerves are firing, number of bursts per time unit, is directly mirrored in real time by the Skin Conductance Algesimeter index which is based on skin conductance peaks per sec:

The Skin Conductance Algesimeter index before, during and after painful events, the skin conductance peaks per second increases (mirroring increased activity in the skin sympathetic nerves) during painful stimuli. The index goes increases if the patient needs more analgesia.

(Storm H. Skin conductance activity and the stress response from heel stick in premature infants. Archives of Disease in Childhood 2000;83(2):F143-F147.).

The Skin Conductance Algesimeter index is based on the number of burst in the skin sympathetic nerves, mirrored by the skin conductance peaks per second, when assessing pain and nociceptive stimuli as well as withdrawal symptoms.