Anesthesia type




Lines and access



Standard 5-lead ECG

Primary anesthetic considerations

Delay surgery to correct electrolyte abnormalities and hypovolemia


Decompress stomach prior to induction Modified RSI


Resume feeding

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Editor rating
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A pyloromyotomy is a surgical procedure performed to correct pyloric stenosis in infants. Pyloric stenosis typically presents during the first 3 months of life, classically with projectile vomiting, poor feeding, and dehydration, though some or all of these may not be present if diagnosed early.[1] Surgery is urgent but not emergent, and should be delayed to correct electrolyte abnormalities and provide intravenous fluid resuscitation.



  • Pyloric stenosis

Surgical procedure

The procedure is most commonly performed laparoscopically, but can also be performed open through a small incision.[2] After establishing access to the pylorus and identification of the hypertrophied pyloric muscle, the outer layers of tissue and muscle are cut to the mucosa. The two portions of the pylorus muscle are then tested for mobility and the mucosa is inspected for any unintentional damage prior to closure.

Preoperative management

Patient evaluation

System Considerations
  • Assess suitability for modified RSI vs. awake fiberoptic
  • Frequent projectile common, but not always present if diagnosed early[3]
  • Palpable "olive-like" mass in right upper quadrant of abdomen[4]

Electrolyte abnormalities and volume status

Patients may be hypovolemic and/or have electrolyte abnormalities from frequent vomiting, including:

  • Metabolic alkalosis from acid loss
    • Respiratory compensation leading to hypoventilation and increased arterial pCO2
  • Secondary hyperaldosteronism from decreased blood volume
    • Hypokalemia
    • ± Hypernatremia
  • Hypochloremia
  • Hypoglycemia

Surgery should be delayed to correct electrolyte abnormalities and provide fluid resuscitation. Recommended preoperative thresholds include:[5]

  • pH ≤7.45 (base excess ≤3.5)
  • Bicarbonate <26 mmol/L
  • Sodium ≥132 mmol/L
  • Potassium ≥3.5 mmol/L
  • Chloride ≥100 mmol/L
  • Glucose ≥4.0 mmol/L (72 mg/dL)

Labs and studies

  • Basic metabolic panel

Operating room setup

Patient preparation and premedication

  • Fluid resuscitation, electrolyte correction, and stomach decompression

Regional and neuraxial techniques

Pyloromyotomy can be performed under spinal anesthesia with potential benefits of reduced operating room time and decreased risk of postoperative apnea. However, spinal anesthesia is often inadequate, requiring supplemental sedation and presenting aspiration risk without a secure airway.[6][7] Additionally, neuraxial anesthesia is not as well studied for laparoscopic pyloromyotomy which is currently the more common surgical approach.[8]

Intraoperative management

Monitoring and access

  • Standard monitors
  • Preoperative IV recommended

Induction and airway management

  • Decompress stomach via OG or NG in 3 positions immediately prior to induction[9]
    • Supine
    • Left lateral decubitus
    • Right lateral decubitus
  • Modified rapid sequence induction recommended
    • Traditional RSI with cricoid pressure shown to increase incidence of hypoxemia without additional reduction in aspiration[10]
    • IV typically already in place for fluid resuscitation and electrolyte correction
  • Awake intubation has fallen out of favor
    • Associated with more attempts and longer intubation time compared to RSI[11]
  • Inhalation induction possible
    • Some evidence to suggest no increased risk of aspiration or hypoxemia[12]
    • Unclear benefit if IV is present preoperatively


Maintenance and surgical considerations

  • Consider risk of postoperative apnea if using opioids


  • Extubate awake

Postoperative management


  • PACU
  • Resume feeding within hours
    • Moderate regurgitation is common and should not delay resuming feeds

Pain management

  • Acetaminophen
  • Careful use of opioids given risk of postoperative apnea

Potential complications[13][14]

  • Incomplete pyloromyotomy
  • Perforated mucosa
  • Wound infection
  • Fascial dehiscence
  • Incisional hernia
  • Postoperative bleeding

Procedure variants

Laparoscopic pyloromyotomy Open pyloromyotomy
Unique considerations
Surgical time
Postoperative disposition
Pain management
Potential complications


  1. Taylor, Nicole D.; Cass, Daniel T.; Holland, Andrew J. A. (2013-01). "Infantile hypertrophic pyloric stenosis: has anything changed?". Journal of Paediatrics and Child Health. 49 (1): 33–37. doi:10.1111/jpc.12027. ISSN 1440-1754. PMID 23198903. Check date values in: |date= (help)
  2. Askew, Nathan (2010). "An overview of infantile hypertrophic pyloric stenosis". Paediatric Nursing. 22 (8): 27–30. doi:10.7748/paed.22.8.27.s27. ISSN 0962-9513. PMID 21066945.
  3. Taylor, Nicole D.; Cass, Daniel T.; Holland, Andrew J. A. (2013). "Infantile hypertrophic pyloric stenosis: has anything changed?". Journal of Paediatrics and Child Health. 49 (1): 33–37. doi:10.1111/jpc.12027. ISSN 1440-1754. PMID 23198903.
  4. Macdessi, J.; Oates, R. K. (1993-02-27). "Clinical diagnosis of pyloric stenosis: a declining art". BMJ (Clinical research ed.). 306 (6877): 553–555. doi:10.1136/bmj.306.6877.553. ISSN 0959-8138. PMC 1677170. PMID 8461768.
  5. van den Bunder, Fenne A. I. M.; Hall, Nigel J.; van Heurn, L. W. Ernest; Derikx, Joep P. M. (2020). "A Delphi Analysis to Reach Consensus on Preoperative Care in Infants with Hypertrophic Pyloric Stenosis". European Journal of Pediatric Surgery: Official Journal of Austrian Association of Pediatric Surgery ... [et Al] = Zeitschrift Fur Kinderchirurgie. 30 (6): 497–504. doi:10.1055/s-0039-3401987. ISSN 1439-359X. PMID 31958865.
  6. Ing, Caleb; Sun, Lena S.; Friend, Alexander F.; Roh, Arthur; Lei, Susan; Andrews, Howard; Li, Guohua; Williams, Robert K. (2016). "Adverse Events and Resource Utilization After Spinal and General Anesthesia in Infants Undergoing Pyloromyotomy". Regional Anesthesia and Pain Medicine. 41 (4): 532–537. doi:10.1097/AAP.0000000000000421. ISSN 1532-8651. PMC 4912426. PMID 27281725.
  7. Sánchez-Conde, María Pilar; Díaz-Alvarez, Agustín; Palomero Rodríguez, Miguel Ángel; Garrido Gallego, María Isabel; Martín Rollan, Guillermo; de Vicente Sánchez, Jesús; Laporta Báez, Yolanda; Vaquero Roncero, Luis Mario; Rodríguez López, José María (2019). "Spinal anesthesia compared with general anesthesia for neonates with hypertrophic pyloric stenosis. A retrospective study". Paediatric Anaesthesia. 29 (9): 938–944. doi:10.1111/pan.13710. ISSN 1460-9592. PMID 31322795.
  8. Islam, Saleem; Larson, Shawn D.; Kays, David W.; Irwin, Maria D.; Carvallho, Norman (2014-10). "Feasibility of laparoscopic pyloromyotomy under spinal anesthesia". Journal of Pediatric Surgery. 49 (10): 1485–1487. doi:10.1016/j.jpedsurg.2014.02.083. ISSN 1531-5037. PMID 25280651. Check date values in: |date= (help)
  9. Cook-Sather, S. D.; Liacouras, C. A.; Previte, J. P.; Markakis, D. A.; Schreiner, M. S. (1997). "Gastric fluid measurement by blind aspiration in paediatric patients: a gastroscopic evaluation". Canadian Journal of Anaesthesia = Journal Canadien D'anesthesie. 44 (2): 168–172. doi:10.1007/BF03013006. ISSN 0832-610X. PMID 9043730.
  10. Park, Raymond S.; Rattana-Arpa, Sirirat; Peyton, James M.; Huang, Jia; Kordun, Anna; Cravero, Joseph P.; Zurakowski, David; Kovatsis, Pete G. (2021-02-01). "Risk of Hypoxemia by Induction Technique Among Infants and Neonates Undergoing Pyloromyotomy". Anesthesia and Analgesia. 132 (2): 367–373. doi:10.1213/ANE.0000000000004344. ISSN 1526-7598. PMID 31361669.
  11. Cook-Sather, S. D.; Tulloch, H. V.; Cnaan, A.; Nicolson, S. C.; Cubina, M. L.; Gallagher, P. R.; Schreiner, M. S. (1998). "A comparison of awake versus paralyzed tracheal intubation for infants with pyloric stenosis". Anesthesia and Analgesia. 86 (5): 945–951. doi:10.1097/00000539-199805000-00006. ISSN 0003-2999. PMID 9585274.
  12. Scrimgeour, Gemma E.; Leather, Nicholas W. F.; Perry, Rachel S.; Pappachan, John V.; Baldock, Andrew J. (2015). "Gas induction for pyloromyotomy". Paediatric Anaesthesia. 25 (7): 677–680. doi:10.1111/pan.12633. ISSN 1460-9592. PMID 25704405.
  13. van den Bunder, Fenne A. I. M.; van Heurn, Ernest; Derikx, Joep P. M. (2020-01-15). "Comparison of laparoscopic and open pyloromyotomy: Concerns for omental herniation at port sites after the laparoscopic approach". Scientific Reports. 10 (1): 363. doi:10.1038/s41598-019-57031-4. ISSN 2045-2322. PMC 6962153. PMID 31941898.
  14. "Chapter 46. Operative Management of Pyloric Stenosis: Pyloromyotomy". Current Procedures: Surgery. Rebecca M. Minter, Gerard M. Doherty. New York: McGraw-Hill Medical. 2010. ISBN 0-07-145316-4. OCLC 689994897.CS1 maint: others (link)