In older and cognitively limited persons it is recommended to use the Abbey Pain Scale [16]. In infants it is recommended to use the FLACC-Score [17] or the discomfort and pain scale for children [18].

In addition, fear and anxiety should also be rated in all burn patients. This can be done by applying the Burn Specific Pain Anxiety Scale [19].

Pain is measured at rest as well as on movement. Here, the pain quality (chronic pain, breakthrough pain, pain caused by the treatment) should be rated separately. Pain after the administration of analgesics must also be rated in regular intervals to document the efficacy or inefficacy of the analgesics.

In the early phase after the burn trauma, rating should be carried out every 2 to 4 hours. In paincontrolled patients it is sufficient to rate the pain twice a day. All collected data must be diligently documented. By visualizing the pain it is possible to identify the pain intensity in sufficient time and to evaluate the efficacy of the pain management correctly.

The rating procedures must be sufficiently explained to the patients. The nursing staff must also be trained and instructed regularly about the procedures. The patients’ pain must not be evaluated based on the personal experiences of the health care professional. Studies have shown wide gaps between the self-assessment of the burn patient and the observational assessment done by the health care personnel [20].

A standardized pain rating contributes to a successful pain management: patients suffering from pain can be identified systematically and in due time. In addition it is possible to define an exact titration of opioids as well as target parameters with the health care personnel and the patient.

Pain management and analgesics

Pharmacokinetics in severe burns

Severe burns cause drastic alterations in the pharmacokinetics of numerous pharmaceuticals.

Immediately after the burn trauma, burn patients might develop a systemic inflammatory response syndrome(SIRS)whichcausesmassivehemodynamic alterations. The clearance of the pharmaceuticals is reduced due to a hypoperfusion of the

organs caused by macro and microcirculatory disorders. In the hypermetabolic phase that follows, the clearance of the pharmaceuticals is increased.

In burns > 20% body surface the incidence of a generalized capillary leak and high protein loss through the wound and into the interstitium is increased. Alterations in the overall protein content cause differences in the fraction of protein-bound and non- protein-bound free pharmaceuticals. That is the reason why the effect of pharmaceuticals with high protein binding (e. g. benzodiazepines) is difficult to manage.

During the management of severe burns the total body water increases and the volume of distribution of numerous pharmaceuticals is increased. Especially in intensive care patients the alteration of the volume can come up to several liters, which can cause a redistribution of the active substances into the extracellular space within a few hours. There the pharmaceuticals can not be effective anymore. This apparent drug tolerance must not be confused with a pharmacodynamic drug tolerance.

In large burns a considerable amount of pharmaceuticals is lost through the wound surface.

Form of administration [21]

In the acute phase it is recommended to administer intravenously.

Intramuscular or subcutaneous injections must be avoided since the resorption ratio in the muscles and the skin vary, the action time is delayed (compared to an intravenous application) and the injection causes unnecessary pain. In the acute phase after the burn trauma, skin and muscles are constricted to a maximum. Thus this paper does not provide any information on the dosage for an intramuscular administration.

A peroral administration can start as soon as the patient is ready to receive it and if there are no con- tra-indications as for example gastrointestinal motility or resorption disorders.

Transdermal administration is only recommended if the skin is not damaged or already healed. Scarred areas do not give good indications of the resorption ratio. Furthermore, the patches might loos-