REVIEW ARTICLE Delayed Treatment of Decompression Sickness with Short, No-Air-Break Tables: Review of 140 Cases Paul Cianci and John B. Slade,Jr. CIANCI P, SLADE JR JB. Delayed treatment of decompression sick- increasing frequency, often having dived very provoc- ness with short, no-air-break tables: review of 140 cases. Aviat Space ative profiles, many suffering from severe DCS, and Environ Med 2006; 77:1003–8. Introduction: Most cases of decompression sickness (DCS) in the U.S. with long delays to treatment. are treated with hyperbaric oxygen using U.S. Navy Treatment Tables 5 In 1963 and 1964, the Navy Experimental Dive Unit and 6, although detailed analysis shows that those tables were based on received reports of 133 cases of DCS in which the stan- limited data. We reviewed the development of these protocols and offer dard USN tables at the time were used (28). Full relief an alternative treatment table more suitable for monoplace chambers did not result in 24% of initial recompressions. When that has proven effective in the treatment of DCS in patients presenting to our facility. Methods: We reviewed the outcomes for 140 cases of outcomes using USN Tables 3 and 4 were analyzed, a DCS in civilian divers treated with the shorter tables at our facility from 47% incidence of failure of the first treatment was January 1983 through December 2002. Results: Onset of symptoms noted. However, there were no instances of treatment averaged 9.3 h after surfacing. At presentation, 44% of the patients failure when DCS had occurred following rigid USN demonstrated mental aberration. The average delay from onset of symp- diving protocols. toms to treatment was 93.5 h; median delay was 48 h. Complete recovery in the total group of 140 patients was 87%. When 30 patients Noteworthy in the initial report of Goodman and with low probability of DCS were excluded, the recoveryDelivered rate was 98%. by IngentaWorkman to: (9) was that of the 79 cases submitted using All patients with cerebral symptoms recovered. Patients with the highest the shorter O2 tables, only 50 had adequate documen- severity scores showed a high rate of completeNaval recovery Aerospace (97.5%). Dis- Medicaltation to determineInstitute speed of relief. Yet these new tables cussion: Short oxygen treatment tables as originally described by Hart were based on obtaining complete relief within 10 min are effective in the treatment of DCS, even with long delays toIP definitive : 214.1.69.249 recompression that often occur among civilian diversWed, presenting 02 May to a 2007of pressurization 20:01:35 at only 33 ft, which was their initial major Divers Alert Network referral center. compression procedure, or at 60 ft, which was recom- Keywords: decompression sickness, short oxygen treatment tables. mended later. If relief was obtained within 10 min at 33 ft, the patient was maintained at that depth for 30 min and then brought to the surface at the rate of 1 ft ⅐ Ϫ HE STANDARD TREATMENT for decompression min 1. If relief was not obtained within 10 min at 33 ft, Tsickness (DCS) in divers is hyperbaric oxygen. In the patient was compressed to 60 ft and observed. If the United States, such cases are generally treated using relief was then not complete at 60 ft within 10 min, a U.S. Navy (USN) Treatment Tables 5 and 6, which were compression to 165 ft was recommended. developed in the late 1960s for use in multiplace cham- An analysis of the data showed that for the shorter, bers. Detailed review of the development process indi- shallower table, total treatment time could vary be- cates that they were based on a limited number of cases tween 64 and 74 min and, for the deeper 60-ft excursion, and contain a number of paradoxical features. Reported between 103 and 112 min. These cases were then sub- outcomes of therapy using USN Treatment Tables 5 and jected to retrospective statistical analysis, and it was 6 have varied widely. More recently, some treatment determined that depth of treatment and oxygen expo- centers have used shorter tables suitable for monoplace sure were the major factors contributing to recovery. chambers. Arbitrarily, the U. S. Navy established USN Treatment USN Treatment Table 6 has been the standard of care Tables 5 and 6 by multiplying the minimal adequate in most of the diving community since its promulgation treatment protocol (60 ft for 30 min on 100% oxygen by the U.S. Navy in August 1967, yet few practitioners with a slow ascent to the surface for a total treatment are aware of the factors relating to its development. time of 90 min) by a factor of 1.5 and 3.0, respectively. Based on the work of Behnke and Shaw in 1937 (3) and a later report by Yarborough and Behnke (30), the U.S. From the Department of Hyperbaric Medicine, Doctors Medical Navy undertook a retrospective analysis of 79 cases Center, San Pablo, CA. presenting to various USN recompression facilities in This manuscript was received for review in October 2005. It was 1963 and 1964 using short O2 tables then in develop- accepted for publication in July 2006. ment (9). This action was prompted by a high degree of Address reprint requests to: Paul Cianci, M.D., Department of Hyperbaric Medicine, Doctors Medical Center, 2000 Vale Road, San failure with the USN Tables 3 and 4 in use at that time. Pablo, CA 94806; [email protected]. Some of these failures were ascribed to the fact that Reprint & Copyright © by Aerospace Medical Association, Alexan- civilian divers were presenting to USN facilities with dria, VA. Aviation, Space, and Environmental Medicine • Vol. 77, No. 10 • October 2006 1003 DELAYED DCS TREATMENT—CIANCI & SLADE TABLE I. RESULTS OF TREATMENT OF DECOMPRESSION presentation, but 10 of 11 cases treated after 24 h had SICKNESS. “substantial benefit.” Bayne reported on 50 cases of DCS from the USN Total Military Civilian (n ϭ 150) (n ϭ 110) (n ϭ 40) School of Salvage, of which 92% of treatments began within2hofonset (2). Only one case did not obtain Results of First Treatment complete relief at 60 ft. Kizer reported 157 cases treated Relief Complete 127 (84.7%) 102 (92.6%) 25 (62.5%) Relief Substantial 8 (5.3%) 4 (3.7%) 4 (10.0%) by the USN hyperbaric chamber at Pearl Harbor from Residual Substantial 5 (3.3%) 0 (0.0%) 5 (12.5%) 1977–1979 (17). Of these cases, 78% were nonmilitary. A Recurrent Symptoms 10 (6.7) 4 (3.7%) 6 (15.0%) total of 58% of patients obtained complete relief, 25% Ј Treated at 33 only 5 (3.3%) 3 (3.7%) 1 (2.5%) substantial relief, and 17% had significant residual Failure of Initial Treatment symptoms. In 58 cases of DCS reported by Yap, 50% Total Cases 23 (15.4%) 8 (7.3%) 15 (27.5%) enjoyed complete relief, with a mean delay to treatment Pain Only 4 (17.4%) 3 (37.5%) 1 (6.6%) of 48 h (29). All 11 Type I (pain only) cases obtained Serious Symptoms 29 (82.6%) 5 (62.5%) 14 (93.4%) complete relief or more than 50% recovery, but 3 Type Results of Second Treatment II (neurological) cases showed no response. Gray, re- Relief Complete 134 (89.3%) 106 (96.3%) 28 (70.0%) porting on 812 DCS cases treated by the U. S. Navy Relief Substantial 9 (6.0%) 4 (3.7%) 5 (12.5%) between 1971 and 1981, showed an 81% chance of com- Residual Substantial 7 (4.7%) 0 (0.0%) 7 (17.5%) plete relief on the first treatment, with an overall final Recurrent Symptoms 0 (0.0%) 0 (0.0%) 0 (0.0%) Number Re-Treated 10 (6.7%) 4 (3.7%) 6 (15.0%) success rate of 94% (10). It was noted that “substantial relief” was a subjective term, which may have meant Modified from Workman (28), with permission. residual soreness or neurologic deficit. Green et al., showed a 96% overall success rate at the USN Experi- mental Dive Unit in 208 cases treated between 1976 and Because of the concern for oxygen toxicity, air breaks 1988 (11). They noticed no difference in efficacy be- were added. Thus, USN Table 5 (total time 135 min) and tween USN Tables 5 and 6. USN Table 6 (total time 285 min) were promulgated to Van Hulst analyzed 10 yr of recompression treat- the USN fleet in August 1967. ments from the Netherlands (26). USN Table 6 was used In 1968 Workman reported on the experience with in 88% of the 65 cases, and complete recovery was the new USN tables (28). By now, there were 150 pa- obtained in 77% of cases with delays to treatment of less tients in the series: 110 military and 40 civilians.Delivered Symp- by Ingentathan 12 h to: and in 43% of cases with delays of 24 h or toms appeared within 60 min of surfacingNaval in Aerospace 66 military Medicalmore. Kovacevic Institute et al. analyzed 154 cases of DCS divers (60%) and in 36 (96%) of the civilians. Pain-onlyIP : 214.1.69.249treated by the Yugoslavian Navy from 1967 to 1988 (20). DCS was suffered by 64% of the militaryWed, cohort 02 May and 2007USN 20:01:35 Table 6 was used most of the time. All Type I cases 15% of the civilians, leaving 36% of the USN divers and showed complete recovery, but 30 cases of Type II had 85% of the civilians with more serious signs and symp- residual symptoms. Ball (1) published a study in which toms.