title: Intraoperative medications associated with hemodynamically significant anaphylaxis.
abstract: OBJECTIVE
  To facilitate the identification of drugs and patient factors associated with hemodynamically significant anaphylaxis.
  
  
  METHODS
  Using an existing database containing complete perioperative records, instances of hemodynamically significant anaphylaxis were identified using a physiologic and treatment-based screening algorithm. All cases were manually reviewed by 2 clinicians, with a third adjudicating disagreements, and confirmed cases were matched 3:1 with control cases. Intraoperative medications given in instances of hemodynamically significant anaphylaxis and patient risk factors were compared with control cases.
  
  
  METHODS
  University of Michigan Hospital, a large, tertiary care hospital.
  
  
  METHODS
  All adult patients undergoing surgery between January 1, 2004, and January 5, 2015.
  
  
  METHODS
  None.
  
  
  METHODS
  Incidence of hemodynamically significant anaphylaxis during anesthesia. Patient risk factors and intraoperative medications associated with hemodynamically significant anaphylaxis.
  
  
  RESULTS
  Hemodynamically significant anaphylaxis occurred in 55 of 461 986 cases (1 in 8400). Hemodynamically significant anaphylaxis occurred in 52 patients, with 1 patient experiencing 3 instances and another patient 2 instances. Only 1 drug was associated with an increased risk of hemodynamically significant anaphylaxis: protamine (odds ratio, 11.78; 95% confidence interval, 1.40-99.26; P=.0233). No category of drugs was associated with increased risk. Of patient risk factors, only personal history of anaphylaxis was associated with an increased risk (odds ratio, 77.1; 95% confidence interval, 10.46-567.69; P=<.0001). Postoperative follow-up and evaluation of patients were low at our institution. A serum tryptase level was sent in only 49% of cases, and 41% of levels were positive, an overall positive rate of 20% of cases. Following instances of hemodynamically significant anaphylaxis, only 29% of patients were seen and evaluated by an allergist at our institution.
  
  
  CONCLUSIONS
  Hemodynamically significant anaphylaxis is a rare complication of anesthesia, with an incidence consistent with the existing literature. Contrary to most existing literature, only protamine was associated with increased risk. A personal history of anaphylaxis appears to best predict risk of hemodynamically significant anaphylaxis.
authors.affiliation: Department of Anesthesiology, Vanderbilt University Medical Center, 1211 21st Ave S, Suite 526, Nashville, TN 37212. Electronic address: Robert.e.freundlich@vanderbilt.edu.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Freundlich
authors.affiliation: Department of Anesthesiology, University of Michigan, 1500 E Medical Center Dr, U1H247, SPC 5048, Ann Arbor, MI 48109. Electronic address: neald@med.umich.edu.
authors.forename: Neal M
authors.initials: NM
authors.lastname: Duggal
authors.affiliation: Department of Anesthesiology, University of Michigan, 1500 E Medical Center Dr, U1H247, SPC 5048, Ann Arbor, MI 48109. Electronic address: mhousey@med.umich.edu.
authors.forename: Michelle
authors.initials: M
authors.lastname: Housey
authors.affiliation: Department of Anesthesiology, University of Michigan, 1500 E Medical Center Dr, U1H247, SPC 5048, Ann Arbor, MI 48109. Electronic address: ttremper@med.umich.edu.
authors.forename: Tyler T
authors.initials: TT
authors.lastname: Tremper
authors.affiliation: Department of Anesthesiology, University of Michigan, 1500 E Medical Center Dr, U1H247, SPC 5048, Ann Arbor, MI 48109. Electronic address: engorenm@med.umich.edu.
authors.forename: Milo C
authors.initials: MC
authors.lastname: Engoren
authors.affiliation: Department of Anesthesiology, University of Michigan, 1500 E Medical Center Dr, U1H247, SPC 5048, Ann Arbor, MI 48109. Electronic address: sachinkh@med.umich.edu.
authors.forename: Sachin
authors.initials: S
authors.lastname: Kheterpal
mesh_terms: D000707:Anaphylaxis / Q000139:chemically induced*; D016208:Databases, Factual; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006494:Heparin Antagonists / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D007430:Intraoperative Care / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011479:Protamines / Q000009:adverse effects*; D012307:Risk Factors
chemical_list: D006494:Heparin Antagonists; D011479:Protamines
keywords: Allergens; Anaphylaxis; Anesthesiology; Hypersensitivity; Risk factors