Definition of pain in newborns with surgical pathology in the traditional way (change the child's behavior, skin color, heart rate, mean arterial pressure, body temperature, blood gas parameters) is subjective. The "Med-Storm" pain stress detector, manufactured by "Med-Storm Innovation AS" (Norway) allows the quantification of pain during and after surgery in infants. For a small sample, specificity was 76%, sensitivity--89%. Important indicator was the peak skin conductance. The change in the area under the curve was less often, but indicated the need of analgesia dose change.