Contents Introduction .....................................................................................................................................1 Chapter 1 Historical Perspective .....................................................................................................7 Robert Boyle (1627 - 1691)................................................................................................................7 Rediscovery .......................................................................................................................................8 Caissons Disease ...............................................................................................................................8 Paul Bert (1833-1886) .....................................................................................................................10 John Scott Haldane (1860-1936) .....................................................................................................12 US Navy ...........................................................................................................................................15 Robert Workman ..............................................................................................................................17 Professor Albert Bühlmann (1923–1994)..........................................................................................17 Chapter 2 Decompression Principles ............................................................................................21 Overview .........................................................................................................................................21 The Air we Breathe ..........................................................................................................................22 The Effects of Pressure ....................................................................................................................24 Dalton’s Law ....................................................................................................................................25 The Lungs........................................................................................................................................26 Henry’s Law .....................................................................................................................................29 Diffusion ..........................................................................................................................................30 Gas Transport ..................................................................................................................................31 Perfusion .........................................................................................................................................33 Saturation ........................................................................................................................................34 Tissue compartments ......................................................................................................................35 Half times ........................................................................................................................................36 Supersaturation ...............................................................................................................................38 Critical supersaturation ....................................................................................................................40 Controlling ratio - M-Values .............................................................................................................40 Ascent rates ....................................................................................................................................43 No-Stop dives ..................................................................................................................................47 Bubble Formation ............................................................................................................................48 Silent Bubbles ..................................................................................................................................48 Safety stops .....................................................................................................................................50 Decompression stops ......................................................................................................................52 Oxygen Window ...............................................................................................................................57 Chapter 3 Decompression Illness .................................................................................................61 Burst Lung .......................................................................................................................................61 Arterial Gas Embolism (AGE) ............................................................................................................62 Interstitial Emphysema ....................................................................................................................62 Pneumothorax .................................................................................................................................63 Decompression Sickness .................................................................................................................63 Decompression Classification ..........................................................................................................63 Reclassification of DCS and AGE ......................................................................................................68 Signs and Symptoms .......................................................................................................................69 Symptoms of the Bends by Frequency ............................................................................................70 Time of Onset of Symptoms ............................................................................................................70 Predisposing Factors ........................................................................................................................71 Dehydration .....................................................................................................................................71 Dive profiles.....................................................................................................................................73 Repetitive Diving ..............................................................................................................................75 Temperature ....................................................................................................................................76 Obesity ............................................................................................................................................76 Exercise ...........................................................................................................................................77 Smoking ..........................................................................................................................................79 Age ..................................................................................................................................................80 Flying after diving ............................................................................................................................80 Reverse profile .................................................................................................................................82 Previous injury .................................................................................................................................84 PFO .................................................................................................................................................84 Lung Shunts ....................................................................................................................................88 Doppler Bubble Detection ................................................................................................................89 Medical implications of DCI ..............................................................................................................91 First Aid ...........................................................................................................................................93 Oxygen ............................................................................................................................................94 5 Minute Neurological Exam ............................................................................................................96 Recompression ................................................................................................................................99 In Water Recompression ................................................................................................................105 Omitted Decompression .................................................................................................................108 Chapter 4 Saturation Diving ........................................................................................................111