RT Book, Section
A1 Jameson, J. Larry
A1 Fauci, Anthony S.
A1 Kasper, Dennis L.
A1 Hauser, Stephen L.
A1 Longo, Dan L.
A1 Loscalzo, Joseph
SR Print(0)
ID 1167062414
T1 Pain and Its Management
T2 Harrison's Manual of Medicine, 20e
YR 2020
FD 2020
PB McGraw-Hill Education
PP New York, NY
SN 9781260455342
LK accessmedicine.mhmedical.com/content.aspx?aid=1167062414
RD 2024/04/16
AB APPROACH  TO  THE  PATIENTPainPain  is  the  most  common  symptom  that  brings  a  pt  to  a  physician’s  attention.  Management  depends  on  determining  its  cause,  alleviating  triggering  and  potentiating  factors,  and  providing  rapid  and  effective  pain  relief  whenever  possible.  Pain  may  be  of  somatic  (skin,  joints,  muscles),  visceral,  or  neuropathic  (injury  to  nerves,  spinal  cord  pathways,  or  thalamus)  origin.  Characteristics  of  each  are  summarized  in  Table  6-1.Neuropathic  PainDue  to  damage  of  peripheral  or  central  nociceptive  pathways.  Definitions:  neuralgia:  pain  in  the  distribution  of  a  single  nerve,  as  in  trigeminal  neuralgia;  dysesthesia:  spontaneous,  unpleasant,  abnormal  sensation;  hyperalgesia  and  hyperesthesia:  exaggerated  responses  to  nociceptive  or  touch  stimulus,  respectively;  allodynia:  perception  of  light  mechanical  stimuli  as  painful,  as  when  vibration  evokes  painful  sensation.  Reduced  pain  perception  is  called  hypalgesia  or,  when  absent,  analgesia.  Causalgia  is  continuous  severe  burning  pain  with  indistinct  boundaries  and  accompanying  sympathetic  nervous  system  dysfunction  (sweating;  vascular,  skin,  and  hair  changes—sympathetic  dystrophy)  that  occurs  after  injury  to  a  peripheral  nerve.Sensitization  refers  to  a  lowered  threshold  for  activating  primary  nociceptors  following  repeated  stimulation  in  damaged  or  inflamed  tissues;  inflammatory  mediators  play  a  role.  Sensitization  contributes  to  tenderness,  soreness,  and  hyperalgesia  (as  in  sunburn).Referred  pain  results  from  the  convergence  of  sensory  inputs  from  skin  and  viscera  on  single  spinal  neurons  that  transmit  pain  signals  to  the  brain.  Because  of  this  convergence,  input  from  deep  structures  is  mislocalized  to  a  region  of  skin  innervated  by  the  same  spinal  segment.Chronic  PainThe  problem  is  often  difficult  to  diagnose  with  certainty,  and  pts  may  appear  emotionally  distraught.  Several  factors  can  cause,  perpetuate,  or  exacerbate  chronic  pain:  (1)  painful  disease  for  which  there  is  no  cure  (e.g.,  arthritis,  cancer,  chronic  daily  headaches,  diabetic  neuropathy);  (2)  perpetuating  factors  initiated  by  a  bodily  disease  that  persist  after  the  disease  has  resolved  (e.g.,  damaged  sensory  or  sympathetic  nerves);  (3)  psychological  conditions.  Pay  special  attention  to  the  medical  history  and  to  depression.  Major  depression  is  common,  treatable,  and  potentially  fatal  (suicide).