title: Effect of arterial puncture on ventilation.
abstract: Clinicians frequently assume that during arterial puncture for measuring arterial blood gases patients hyperventilate from pain and anxiety. This assumption leads clinicians to falsely interpret a PaCO2and pH near the upper limit of normal as a chronic respiratory acidosis corrected by an acute respiratory alkalosis.
  
  
  
  Determine if participants hyperventilate during arterial puncture from pain and anxiety.
  
  
  
  We recruited participants from a pulmonary function laboratory referred for arterial blood gas measurement. We excluded those with heart failure and included those with any respiratory condition (COPD, asthma, sleep apnea). We measured end tidal PCO2(PETCO2), respiratory rate, and heart rate 15 min before topical anesthesia, during anesthesia, during arterial puncture, and 15 min later. We assessed generalized anxiety before and measured pain during and after arterial puncture.
  
  
  
  24 participants were recruited (age: 54 ± 12 years; men: 54%). PaCO2was 41 ± 5 mmHg. One had acute respiratory alkalosis. Respiratory rate increased from (19 ± 6 breaths per minute (bpm)) before to a maximum (21 ± 6 bpm) during arterial puncture (p = 0.001). Heart rate was stable throughout. The lowest PETCO2during the procedure (35 ± 5) was similar to PETCO2before the procedure (p = 0.1). The change in PETCO2and respiratory rate did not correlate with pain, anxiety, or lung function.
  
  
  
  Respiratory rate increased slightly during arterial puncture without any change in PETCO2. Hence, acid-base status must be interpreted without the assumption of procedure induced hyperventilation.
authors.affiliation: Division of Pulmonary and Critical Care, John H Stroger Jr Hospital of Cook County, Chicago, IL, USA. Electronic address: asahni@cookcountyhhs.org.
authors.forename: Ashima Synghal
authors.initials: AS
authors.lastname: Sahni
authors.affiliation: Department of Medicine, John H Stroger Jr Hospital of Cook County, Chicago, IL, USA.
authors.forename: Hemil
authors.initials: H
authors.lastname: Gonzalez
authors.affiliation: Division of Pulmonary and Critical Care, John H Stroger Jr Hospital of Cook County, Chicago, IL, USA.
authors.forename: Aiman
authors.initials: A
authors.lastname: Tulaimat
mesh_terms: D000142:Acidosis, Respiratory / Q000097:blood / Q000503:physiopathology*; D001158:Arteries / Q000601:surgery*; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood*; D005260:Female; D006801:Humans; D006985:Hyperventilation / Q000097:blood / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D011446:Prospective Studies; D011677:Punctures / Q000379:methods*; D012119:Respiration
chemical_list: D002245:Carbon Dioxide
keywords: Arterial puncture; End tidal carbon dioxide; Hyperventilation; Hypoventilation