Decision making process for amputation in case of therapy resistant complex regional pain syndrome type-I in a Dutch specialist centre.

Deciding for an amputation in case of complex regional pain syndrome type I (CRPS-I) is controversial. Evidence for favorable or adverse effects of an amputation is weak. We therefore follow a careful and well-structured decision making process. After referral of the patient with the request to amputate the affected limb, it is checked if the diagnosis CRPS-I is correct, duration of complaints is more than 1 year, all treatments described in the Dutch guidelines have been tried and if consequences of an amputation have been well considered by the patient. Thereafter the patient is assessed by a multidisciplinary team (psychologist, physical therapist, anesthesiologist-pain specialist, physiatrist and vascular surgeon). During a multidisciplinary meeting professionals summarize their assessment. Pros and cons of an amputation are discussed, taking into account level of amputation and expectations about post amputation functioning of patient and team. Based on assessments and discussion a consensus based decision is formulated and the patient is informed. If it is decided that an amputation is to be performed, the amputation will follow shortly. If it is decided not to amputate, the decision is extensively explained to the patient. Incidence of patients suffering from therapy resistant CRPS-I referred for amputation is low and because referred patients are strongly in favor of an amputation, a randomized controlled trial will be difficult to perform. Hence level of evidence in favor or against an amputation will remain low. We therefore report our decision making process to facilitate discussion about this difficult and delicate matter.

Chronic pain in rehabilitation medicine.

In this paper the chronicity of pain in non-specific pain syndromes is discussed. Experts in the study of pain with several professional backgrounds in rehabilitation are the authors of this paper. Clinical experience and literature form the basis of the paper. Non-specific low back pain and Complex Regional Pain Syndrome type I (CRPS-I) are discussed in the light of chronic pain. Many definitions of chronic pain exist. Yellow flags are important factors to identify possible chronic pain. In the acute phase of a non-specific pain complaint one should try to identify possible psychosocial inciting risk factors. Behavioural and cognitive treatment seems to be effective for chronic pain patients.

Transfer free energies and average static accessibilities for ribonuclease A in guanidinium hydrochloride and urea solutions.

Isopiestic vapor pressure measurements have been used to obtain free energies of transfer of ribonuclease A from dilute buffer to solutions of either urea or guanidine hydrochloride (GdnHCl) over a wide cosolute concentration range. The free energies of transfer vary monotonically from 0 to -8 kcal/mol in 8 M urea and to -18 kcal/mol in 6 M GdnHCl. These values are not large in relation to free energies of transfer of constituent groups of the protein from water to cosolute solutions of the same concentration. The assumption is made that the magnitude of the free energy of transfer of the protein is governed by the average static accessibility of the constituent groups to the solution. The free energies of transfer to different cosolute concentrations of a hypothetical 100% accessible ribonuclease A were determined using literature values of the free energies of transfer of constituent groups and the amino acid composition. The ratio of the experimentally determined free energy of transfer to the free energy of transfer of the 100% accessible protein gave 11% accessible surface area for the native protein in 1 M GdnHCl or 2 M urea. Additional considerations led to a value of 36% for the accessible surface area of the denatured protein in 6 M GdnHCl or 8 M urea.