The Hawaiian Method
This decompression sickness treatment table was designed for use when more than 30 minutes away from a regular recompression treatment facility.
The urgent nature of the treatment must be recognized and acted upon immediately, inasmuch as nervous tissue of the brain or spinal cord can only be completely revived within the first seven to eight minutes after its oxygen supply has been stopped by the intravascular bubble emboli of decompression sickness.
(Although its use by technical divers is generally discouraged, this method is presented here for the purpose of providing information to readers of these proceedings. Additional comments and suggested modifications to allow for more general applicability of this method are in italics.)
Equipment Required
1. An adequate supply of oxygen on board, i.e., a 120 cu ft capacity or greater bottle, an oxygen-clean hose at least 40 f/12 m long plus fittings, and an oxygen-clean scuba regulator and mouthpiece (NOTE: Use of full face mask with demand regulator is very strongly encouraged for administering oxygen underwater during these treatments).
2. A length of line marked to 30 f/9 m from the waterline, with seat attached, upon which the victim can sit during decompression (the seat should be weighted so as to make victim and seat negatively bouyant).
3. Extra air tanks for victim and attending diver (minimum of two).
4. Anchor rope or sounding float line marked at 165 f/50 m
5. Depth gauge and watch for use by attending diver.
6. Wet suit jacket (or other adequate thermal protection) for use by victim with appropriate weights.
Method
Upon recognizing symptoms or signs of decompression sickness, immediately:
1. Stop the engines (if the boat is already moving).
2. Throw over anchor line and let out 165 f/50 m, or to bottom.
3. Rig one full air tank for victim and another for attendant diver.
4. Put victim in water with one attendant diver (or two, if required) to take victim down anchor line (Extreme caution should be excercised in choice of attendant diver. The risk of DCI ocurring in the attendant diver as a result of the IWR attempt should be very seriously considered).
5. Descend to depth of relief plus 30 f/9 m (not to exceed 165 f/50 m).
6. Keep victim at that depth for 10 minutes.
7. Attending diver and victim start slow ascent with initial rate of 30 f/9 m per minute with stops every minute for assessment of patient's condition.
8. Ascent from maximum depth to oxygen breathing depth should not take less than 10 minutes. Suggested rates of ascents from 165 f/50 m are: 30 f/minute x 2 minutes; 15 f/minute x 2 minutes; 10 f/minutes x 3 minutes; 5 f/minutes x 3 minutes.
9. If patient starts to experience recurrence of any signs or symptoms, return to 10 f/3m deeper stop for 5 minutes, then resume ascent.
10. During deep air breathing period, crew in boat rigs oxygen breathing equipment with regulator (or preferably, full face-mask with demand regulator) attached to hose and line with seat at 30 f/9 m.
11. Upon reaching 30 f/9 m victim switches to oxygen breathing.
12. Victim breathes oxygen at 30 f/9 m for a minimum of 1 hour.
13. If victim had initial symptoms of pain only, and if signs and symptoms are relieved after 1 hour of breathing oxygen, start slow ascent. If victim had signs and symptoms of CNS disease, keep victim at 30 f/9 m on oxygen for one or two additional 30-minute periods. When victim is completely relieved (or emergency transport arrives, or oxygen supply is exhausted), start slow ascent to surface while breathing oxygen (or air if oxygen supply is exhausted).
14. If the in-water recompression is not effective and the supply of oxygen is apparently inadequate, emergency transport to the on-shore recompression chamber should be arranged (Technical divers are strongly encouraged to begin making arrangments for emergency transport to a recompression facility as soon as DCI symptoms become evident). Recompression on oxygen at 30 f/9 m should be continued until the oxygen supply is exhausted or tansport arrives.
15. Even if victim is asymptomatic when reaching surface, have victim breathe oxygen in boat on surface until supply is exhausted. Consult with diving medical officer upon return to shore.