title: The timing and prevalence of intraoperative hypotension in infants undergoing laparoscopic pyloromyotomy at a tertiary pediatric hospital.
abstract: BACKGROUND
  Intraoperative hypotension may be associated with adverse outcomes in children undergoing surgery. Infants and neonates under 6 months of age have less autoregulatory cerebral reserve than older infants, yet little information exists regarding when and how often intraoperative hypotension occurs in infants.
  
  
  OBJECTIVE
  To better understand the epidemiology of intraoperative hypotension in infants, we aimed to determine the prevalence of intraoperative hypotension in a generally uniform population of infants undergoing laparoscopic pyloromyotomy.
  
  
  METHODS
  Vital sign data from electronic records of infants who underwent laparoscopic pyloromyotomy with general anesthesia at a children's hospital between January 1, 1998 and October 4, 2013 were analyzed. Baseline blood pressure (BP) values and intraoperative BPs were identified during eight perioperative stages based on anesthesia event timestamps. We determined the occurrence of relative (systolic BP <20% below baseline) and absolute (mean arterial BP <35 mmHg) intraoperative hypotension within each stage.
  
  
  RESULTS
  A total of 735 full-term infants and 82 preterm infants met the study criteria. Relative intraoperative hypotension occurred in 77%, 72%, and 58% of infants in the 1-30, 31-60, and 61-90 days age groups, respectively. Absolute intraoperative hypotension was seen in 21%, 12%, and 4% of infants in the 1-30, 31-60, and 61-90 days age groups, respectively. Intraoperative hypotension occurred primarily during surgical prep and throughout the surgical procedure. Preterm infants had higher rates of absolute intraoperative hypotension than full-term infants.
  
  
  CONCLUSIONS
  Relative intraoperative hypotension was routine and absolute intraoperative hypotension was common in neonates and infants under 91 days of age. Preterm infants and infants under 61 days of age experienced the highest rates of absolute and relative intraoperative hypotension, particularly during surgical prep and throughout surgery.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Perelman School of Medicine at the University of Pennsylvania and The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Allan F
authors.initials: AF
authors.lastname: Simpao
authors.affiliation: Data Analytics and Enterprise Reporting, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Ahumada
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Perelman School of Medicine at the University of Pennsylvania and The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Gálvez
authors.affiliation: Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania and the Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Bonafide
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Elicia C
authors.initials: EC
authors.lastname: Wartman
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: William
authors.initials: W
authors.lastname: Randall England
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Perelman School of Medicine at the University of Pennsylvania and The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Arul M
authors.initials: AM
authors.lastname: Lingappan
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Perelman School of Medicine at the University of Pennsylvania and The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Todd J
authors.initials: TJ
authors.lastname: Kilbaugh
authors.affiliation: Department of Biostatistics in Pediatrics, Perelman School of Medicine at the University of Pennsylvania and the Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Abbas F
authors.initials: AF
authors.lastname: Jawad
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Perelman School of Medicine at the University of Pennsylvania and The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Rehman
mesh_terms: D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000706:statistics & numerical data; D005260:Female; D006776:Hospitals, Pediatric; D006801:Humans; D007022:Hypotension / Q000453:epidemiology*; D007223:Infant; D007231:Infant, Newborn; D007431:Intraoperative Complications / Q000453:epidemiology*; D010535:Laparoscopy; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods* / Q000706:statistics & numerical data; D015143:Philadelphia / Q000453:epidemiology; D015995:Prevalence; D011708:Pylorus / Q000601:surgery*; D062606:Tertiary Care Centers; D013997:Time Factors
keywords: anesthesia; blood pressure; hypotension; infant; perioperative period; pyloric stenosis