Page 163 - BSAVA Guide to Pain Management in Small Animal Practice

BSAVA Guide to Pain Management in Small Animal Practice

VetBooks.ir

Splenic mass in a Labrador Retriever
3 associated with an acute haemoabdomen.

pain may be associated with the presence of
the tumour itself or may be a complication of Pathological fracture in the femoral neck of
cancer surgery e.g. phantom pain after limb or a Leonberger at the site of a primary bone
digit amputation . It can also be associated with tumour osteosarcoma .
the use of ad uvant therapies or the presence of
chronic co morbidities see above . ■ Visceral pain arises from stretching,
Cancer associated pain may initially be acute distension or obstruction of viscera. his type
but if a tumour is allowed to reach an advanced of pain is poorly locali ed and is associated
stage before pain is recogni ed and managed with a dull, deep, cramping and aching
e ectively, a chronic pain state of varying sensation see igure 7. for examples of
severity may develop aynor, . It is widely tumours that can cause visceral pain .
recogni ed that cancer pain therefore more often ■ Neuropathic pain occurs due to a lesion or
mimics a chronic rather than an acute pain disease that a ects the tissues of the
model Christo and a loomdoost, . somatosensory nervous system itself. his
A patient with chronic cancer associated type of pain may occur through direct tumour
pain may also experience episodes of compression or in ltration of nerves or nerve
breakthrough pain. An example would be the roots or may be associated with tumour
occurrence of a pathological fracture at the site treatment. It is associated with a burning,
of a primary bone tumour igure . . A period shooting or electric shock like sensation.
of weeks of chronic pain may precede an acute
pain episode associated with collapse of the wo other important concepts in the
cortical bone. pathophysiology and management of cancer
associated pain are the processes of wind up
Type and localization and sensiti ation. ind up occurs due to
persistent nociceptive input to the spinal cord
Cancer associated pain may be somatic,
visceral or neuropathic in origin aynor, 8 . leading to potentiation of sensory pathways and
ur understanding of the associated pain contributes to sensiti ation. Sensiti ation is
sensations is inferred from human reports and associated with a state of pain hypersensitivity
by examining an animal s behaviour. termed allodynia and hyperalgesia .
he complexity of managing cancer
■ Somatic pain arises through tumour or associated pain therefore re ects the need to
treatment associated damage to bones, take into account its origin, intensity, duration
oints, muscle or skin; it is locali ed, and the occurrence of additional factors
constant and throbbing or aching in nature. including wind up and sensiti ation.

158

Ch7H Pain Management.indd 158 19/12/2018 10:46