title: Anesthetic considerations for patients with esophageal achalasia undergoing peroral endoscopic myotomy: a retrospective case series review.
abstract: OBJECTIVE
  Peroral endoscopic myotomy (POEM) is a novel technique for treating esophageal achalasia. During POEM, carbon dioxide (CO2) is insufflated to aid surgical dissection, but it may inadvertently track into surrounding tissues, causing systemic CO2uptake and tension capnoperitoneum. This in turn may affect cardiorespiratory function. This study quantified these cardiorespiratory effects and treatment by hyperventilation and percutaneous abdominal needle decompression (PND).
  
  
  METHODS
  One hundred and seventy-three consecutive patients who underwent POEM were included in this four-year retrospective study. Procedure-related changes in peak inspiratory pressure (pmax), end-tidal CO2levels (etCO2), minute ventilation (MV), mean arterial pressure (MAP), and heart rate (HR) were analyzed. We also quantified the impact of PND on these cardiorespiratory parameters.
  
  
  RESULTS
  During the endoscopic procedure, cardiorespiratory parameters increased from baseline: pmax15.1 (4.5) vs 19.8 (4.7) cm H2O; etCO24.5 (0.4) vs 5.5 (0.9) kPa [34.0 (2.9) vs 41.6 (6.9) mmHg]; MAP 73.9 (9.7) vs 99.3 (15.2) mmHg; HR 67.6 (12.4) vs 85.3 (16.4) min-1(P < 0.001 for each). Hyperventilation [MV 5.9 (1.2) vs 9.0 (1.8) L·min-1, P < 0.001] was applied to counteract iatrogenic hypercapnia. Individuals with tension capnoperitoneum treated with PND (n = 55) had higher peak pmaxvalues [22.8 (5.7) vs 18.4 (3.3) cm H2O, P < 0.001] than patients who did not require PND. After PND, pmax[22.8 (5.7) vs 19.9 (4.3) cm H2O, P = 0.045] and MAP [98.2 (16.3) vs 88.6 (11.8) mmHg, P = 0.013] decreased. Adverse events included pneumothorax (n = 1), transient myocardial ischemia (n = 1), and subcutaneous emphysema (n = 49). The latter precluded immediate extubation in eight cases. Postanesthesia care unit (PACU) stay was longer in individuals with subcutaneous emphysema than in those without [74.9 min (34.5) vs 61.5 (26.8 min), P = 0.007].
  
  
  CONCLUSIONS
  Carbon dioxide insufflation during POEM produces systemic CO2uptake and increased intra-abdominal pressure. Changes in cardiorespiratory parameters include increased pmax, etCO2, MAP, and HR. Hyperventilation and PND help mitigate some of these changes. Subcutaneous emphysema is common and may delay extubation and prolong PACU stay.
authors.affiliation: Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20251, Hamburg, Germany. B.Loeser@uke.de.
authors.forename: Benjamin
authors.identifier: http://orcid.org/0000-0001-9454-3572
authors.initials: B
authors.lastname: Löser
authors.affiliation: Department of Interdisciplinary Endoscopy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Yuki B
authors.initials: YB
authors.lastname: Werner
authors.affiliation: Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20251, Hamburg, Germany.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Punke
authors.affiliation: Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20251, Hamburg, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Saugel
authors.affiliation: Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20251, Hamburg, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Haas
authors.affiliation: Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20251, Hamburg, Germany.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Reuter
authors.affiliation: Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Mann
authors.affiliation: Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Duprée
authors.affiliation: Department of Interdisciplinary Endoscopy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Guido
authors.initials: G
authors.lastname: Schachschal
authors.affiliation: Department of Interdisciplinary Endoscopy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rösch
authors.affiliation: Department of Anesthesiology, Center of Anesthesiology and Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20251, Hamburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Petzoldt
mesh_terms: D000328:Adult; D000762:Anesthesia Recovery Period; D000777:Anesthetics / Q000008:administration & dosage*; D062186:Arterial Pressure / Q000502:physiology; D002245:Carbon Dioxide / Q000008:administration & dosage*; D004931:Esophageal Achalasia / Q000473:pathology / Q000601:surgery*; D004945:Esophagoscopy / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011027:Pneumoperitoneum / Q000209:etiology; D011183:Postoperative Complications / Q000453:epidemiology; D011312:Pressure; D012189:Retrospective Studies; D013352:Subcutaneous Emphysema / Q000453:epidemiology / Q000209:etiology
chemical_list: D000777:Anesthetics; D002245:Carbon Dioxide