CHAPTER 21 — Recompression Therapy
Change A 21-25
21-5.6.5.1
Patient Hydration. Successful treatment of decompression sickness depends upon
adequate hydration. Thirst is an unreliable indicator of the water intake necessary
to compensate for heavy sweating, and isolation of the patient within the recom-
pression chamber makes it difficult to assess his overall fluid balance. By
providing adequate hydration and following the temperature/time guidelines in
Table 21-4, heat exhaustion and heat stroke can be avoided. If the chamber
temperature is above 85°F (29.4°C), tenders should monitor patients for signs of
thermal stress. If the chamber temperature is above 85°F, chamber occupants
should drink approximately one liter of water hourly; below 85°F they should
drink an average of one-half liter hourly. Clear colorless urine in patients and
tenders is a good indication of adequate hydration.
21-5.6.6
Chamber Ventilation. Ventilation is the usual means of controlling oxygen level,
carbon dioxide level, and temperature. Ventilation using air is required for cham-
bers without carbon dioxide scrubbers and atmospheric analysis. A ventilation rate
of two acfm for each resting occupant, and four acfm for each active occupant,
should be used. Chamber ventilation procedures are presented in paragraph
22-5.4. These procedures are designed to assure that the effective concentration of
carbon dioxide will not exceed 1.5 percent SEV (11.4 mmHg) and that, when
oxygen is being used, the percentage of oxygen in the chamber will not exceed 25
percent.
21-5.6.7
Access to Chamber Occupants. Recompression treatments usually require ac-
cess to occupants for passing in items such as food, water, and drugs and passing
out such items as urine, excrement, and trash. Never attempt a treatment longer
than a Treatment Table 6 unless there is access to inside occupants. When doing a
Treatment Table 4, 7, or 8, a double-lock chamber is mandatory because addi-
tional personnel may have to be locked in and out during treatment.
21-5.6.8
Inside Tenders. For Type I decompression sickness, one qualified inside tender
is required. For Type II decompression sickness, medical personnel may have to
be locked into the chamber as the patient’s condition dictates. If one Diving
Medical Officer is on site, the Medical Officer should lock in and out as the
patient’s condition dictates, but should not commit to the entire treatment unless
absolutely necessary. Once committed to remain in the chamber, the Diving
Medical Officer will not be able to aid the treatment as well and consultation with
other medical personnel becomes more difficult.
21-5.6.8.1
Oxygen Breathing. During treatments, all chamber occupants may breathe 100
percent oxygen at depths of 45 feet or shallower without locking in additional
personnel. Tenders should not fasten the oxygen masks to their heads, but should
hold them on their faces. When deeper than 45 feet, at least one chamber occupant
must breathe air.
21-5.6.8.1.1 Table 4. On Table 4, tenders are required to breathe oxygen for 2 hours before
leaving 30 feet and for 2 additional hours during decompression from 30 feet to
the surface.
