RT Book, Section
A1 Bow, E.J.
A2 Hall, Jesse B.
A2 Schmidt, Gregory A.
A2 Wood, Lawrence D.H.
SR Print(0)
ID 2290389
T1 Chapter 47. Approach to Infection in Patients Receiving Cytotoxic Chemotherapy for Malignancy
T2 Principles of Critical Care, 3e
YR 2005
FD 2005
PB The McGraw-Hill Companies
PP New York, NY
SN 9780071416405
LK accessmedicine.mhmedical.com/content.aspx?aid=2290389
RD 2023/05/28
AB Risk  of  infection  increases  as  the  circulating  absolute  neutrophil  count  (ANC)  declines  below  1.0  ×  109/L.  The  greatest  risk  of  bacteremic  infection  occurs  when  the  ANC  is  0.5  ×  109/L)  can  vary  from  21  to  42  days.Intermittent  administration  of  cytotoxic  therapy  for  solid  tissue  malignancies  or  lymphoreticular  malignancies  (low-risk  patients)  is  often  associated  with  a  neutrophil  nadir  at  10  to  14  days  from  beginning  treatment  and  with  periods  of  neutropenia  (ANC  <0.5  ×  109/L)  of  less  than  5  to  7  days.  This  pattern  of  neutrophil  recovery  influences  the  natural  history  of  febrile  neutropenic  episodes.Febrile  episodes  during  neutropenia  are  defined  by  an  oral  temperature  of  38.3°C  (101°F)  or  more  in  the  absence  of  other  noninfectious  causes  of  fever  such  as  administration  of  blood  products  or  pyrogenic  drugs  (e.g.,  cytotoxic  therapy  or  amphotericin  B),  the  underlying  disease,  thromboembolic  or  thrombophlebitic  events,  or  hemorrhagic  events.A  single  neutropenic  episode  may  be  characterized  by  one  or  more  febrile  episodes,  of  which  one  or  more  may  represent  infections.Body  sites  most  often  associated  with  infection  in  the  neutropenic  patient  are  those  associated  with  integumental  surfaces  (skin,  upper  and  lower  respiratory  tract,  and  upper  and  lower  gastrointestinal  tract).Antibacterial  prophylaxis  with  oral  agents  such  as  cotrimoxazole,  norfloxacin,  or  ciprofloxacin  can  reduce  the  frequency  of  febrile  episodes  and  bacteremic  events  in  patients  with  protracted  neutropenia.Patients  undergoing  remission-induction  for  acute  myeloid  leukemia  or  bone  marrow  transplantation  with  a  history  of  herpetic  stomatitis  or  who  are  IgG  seropositive  for  herpes  simplex  virus  (HSV)  are  at  risk  for  severe  herpetic  mucositis.  Such  patients  should  be  given  acyclovir  prophylaxis.Empiric  antimicrobial  therapy  for  suspected  infection  in  the  febrile  neutropenic  patient  usually  is  composed  of  a  broad-spectrum  antibacterial  regimen  of  an  anti-pseudomonal  penicillin  or  carbapenem  administered  as  a  single  agent  (monotherapy).  Aminoglycoside-based  combinations  do  not  add  to  the  efficacy  of  the  single  agent,  but  do  add  toxicity.Neutropenic  patients  responding  to  empiric  antibacterial  therapy  generally  require  at  least  5  days  for  the  response  to  be  observed  in  half  the  cases.  Patients  remaining  febrile  at  5  days  should  be  systematically  re-evaluated,  while  consideration  of  modification  of  the  antimicrobial  regimen  can  be  made  at  day  7  or  8  unless  clinical  deterioration  is  evident.  Glycopeptides  administered  as  second-line  empiric  therapy  for  persistent  fever  after  3  to  5  days  do  not  influence  time  to  defervescence  or  febrile  episode-related  mortality.