title: Arterial blood pressure in anesthetized neonates and infants: a retrospective analysis of 1091 cases.
abstract: BACKGROUND
  Hypotension during general anesthesia in neonates and infants is considered to contribute to poor neurological outcome.
  
  
  OBJECTIVE
  The aim of this retrospective analysis was to determine the incidence of hypotension after induction of anesthesia and sustained hypotension (>10 min) during the anesthesia, and to determine factors contributing to the development of (sustained) hypotension.
  
  
  METHODS
  We performed a retrospective analysis of 1091 electronic anesthesia records from children <1 year. Patients were stratified for age (group 1: <1 month, group 2: 1-3 months, group 3: 4-6 months, group 4: >6 months). Hypotension was defined as a mean arterial pressure (MAP) <35 mmHg in patients ≤6 months and <43 mmHg in patients >6 months.
  
  
  RESULTS
  The incidence of hypotension after induction was highest in group 1 (25.5%) [P = 0.009 vs group 2 (13.3%), P < 0.0001 vs groups 3 (3.4%) and 4 (1.0%)], in group 2, it was higher than in groups 3 and 4 (P < 0.0001), and in group 3, it was higher than in group 4 (P = 0.033). The incidence of sustained hypotension was highest in group 1 (43.6%) (P < 0.0001 vs groups 2-4), followed by group 2 (15.7%) [P < 0.0001 vs group 3 (3.4%) and P = 0.006 vs group 4 (8.8%)] and group 4 (P = 0.004 vs group 3). Hypotension after induction occurred more often in emergency procedures than in elective procedures in groups 1 (P = 0.002), 2 (P = 0.029), and 3 (P = 0.037).
  
  
  CONCLUSIONS
  Hypotension, both postinduction and sustained during surgery, is a common phenomenon in anesthetized children under 1 year, peaking in neonates. Generally accepted lower limits of MAP in anesthetized infants urgently need to be defined, enabling us to develop anesthesia strategies avoiding cerebral hypoperfusion.
authors.affiliation: Department of Anaesthesia, Erasmus University Medical Center - Sophia Children's Hospital, Rotterdam, The Netherlands.
authors.forename: Frank
authors.initials: F
authors.lastname: Weber
authors.affiliation: Department of Anaesthesia, Erasmus University Medical Center - Sophia Children's Hospital, Rotterdam, The Netherlands.
authors.forename: Gijsbert H M
authors.initials: GH
authors.lastname: Honing
authors.affiliation: Department of Anaesthesia, Erasmus University Medical Center - Sophia Children's Hospital, Rotterdam, The Netherlands.
authors.forename: Gail P
authors.initials: GP
authors.lastname: Scoones
mesh_terms: D000768:Anesthesia, General; D062186:Arterial Pressure; D005260:Female; D006801:Humans; D007022:Hypotension / Q000453:epidemiology*; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012189:Retrospective Studies; D013997:Time Factors
keywords: age; general anesthesia; induction of anesthesia; neonate infant; neurodevelopment