Unexpected Decompression Arielle Filiberti MD UCSF Fresno Wilderness Fellow WMS Winter Conference: GME Mini-Lectures A Brief History of Decompression Illness (DCI) • New technology: the Caisson • Developed in 1792 • Compressed air used to force out water and debris • Allowed construction of the Brooklyn Bridge and Eads Bridge A Brief History of DCI • The Bends • Musculoskeletal • The Chokes • Respiratory • The Staggers • Neurologic Cliffs Notes: Decompression Illness 1. Barotrauma • Air spaces do not equilibrate to pressure changes • Volume of air contracts or expands • Can occur with ascent or descent • Ear, sinus, and dental • Pulmonary • Arterial gas embolism 2. Decompression Sickness • As ambient pressure decreases, gas bubbles form • Pain, pruritis • Venous gas embolism and ischemia • Increased risk flying after a “dive” or other event Modern Compressed Air Workers (CAW’s) • CAW’s regulated by OSHA • Tunnel building • Nuclear power plants • Plane inspectors • CDC claims decompression guidelines are inadequate • CAW’s are left at risk In-Flight Decompression Illness • Cabins pressurized equivalent 7,000-8,000’ • Failure to pressurize during ascent • Unanticipated loss of cabin pressure • Large cabins provide “buffer” • Small cabins can decompress in <0.5 second Military Training • Depressurization training to simulate hypoxia and unanticipated loss of cabin pressure • Sudden loss of pressure from 4,000 to 18,000 ft • Increased risk with commercial flight after this training • Case report of 3 trainees requiring hyperbaric chamber after a commercial flight home Ground Level Cabin Malfunction • 4 case reports of uncontrolled cabin pressurization while grounded • Can result in severe DCI needing hyperbaric chamber Take-home Points 1. Consider DCI in any situation where pressure differentials exist 2. Patients can present distant from where the decompression happened 3. Treatment is the same regardless of etiology • IV fluids • Oxygen • Hyperbaric chamber 4. Call DAN! References Allan GM, Kenny D. High-altitude decompression illness: case report and discussion [published correction appears in CMAJ. 2003 Nov 25;169(11):1149]. CMAJ. 2003;169(8):803-807. Andersen HL. Decompression sickness during construction of the Great Belt Tunnel, Denmark. Undersea Hyperb Med. 2002;29(3):172-188. Butler WP. Caisson disease during the construction of the Eads and Brooklyn Bridges: A review. Undersea Hyperb Med. 2004;31(4):445-459. Centers for Disease Control and Prevention (CDC). Decompression Sickness and Tunnel Workers: Limitations of the Current OSHA Decompression Tables. https://www.cdc.gov/niosh/topics/decompression/limitations.html. Updated on June 18, 2012. Accessed on November 27, 2020. Lee KJ, Sanou AZ. Decompression Sickness in the F/A-18C After Atypical Cabin Pressure Fluctuations. Aerosp Med Hum Perform. 2018;89(5):478-482. doi:10.3357/AMHP.5027.2018 ONeill OJ, Haftel A, Murphy-Lavoie HM. Hyperbaric Treatment Of Compressed Air Workers, Caissons, Tunneling, Bounce Diving, and Saturation Diving. In: StatPearls. Treasure Island (FL): StatPearls Publishing; September 14, 2020. Pilmanis AA, Sears WJ. Physiological hazards of flight at high altitude. Lancet. 2003;362 Suppl:s16-s17. doi:10.1016/s0140- 6736(03)15059-3 Skybrary. Pressurisation Problems: Guidance for Controllers. https://www.skybrary.aero/index.php/Pressurisation_Problems:_Guidance_for_Controllers#Accidents_.26_Incidents. Updated on March 14, 2020. Accessed on December 1, 2020. Weinhouse GL, Chandy D. Complications of SCUBA diving. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate Inc. https://www.uptodate.com/contents/complications-of-scuba-diving. Accessed February 11, 2021. Zhang JX, Berry JR, Beckstrand DP. Explosive Decompression with Resultant Air Gas Embolism in a Fourth Generation Fighter at Ground Level. Aerosp Med Hum Perform. 2016;87(11):963-967. doi:10.3357/AMHP.4632.2016.