Report on Decompression Illness, Diving Fatalities and Project Dive

Section 3 - Dive InjuriesTable 3.1-4Perceived SeverityIndex (PSI).Perceived Severity Index (PSI)The Perceived Severity Index (PSI) was introduced in the 2002report and is continued in this year. This classification system isbased on the perceived severity of symptoms associated withd e c o m p ression illness, according to DAN physicians andresearchers. The PSI categories are listed in Table 3.1-4 in order ofdecreasing severity: a) Serious Neurological; b) Cardiopulmonary;c) Mild Neurological; d) Pain; e) Lymphatic or Skin; and d)Constitutional or Nonspecific. The categories are hierarchical in theorder listed. This means, for example, that a case categorized forserious neurological symptoms could also have pain, but that a casecategorized for pain could not have serious neurological manifestations.Perceived Severity Index<strong>Report</strong>ed Signs or Symptoms1. Serious Neurological bladder or bowel dysfunctionaltered coordination, difficulty walking, gaitaltered consciousnessaltered hearing, tinnitus, vertigodifficulty talking, altered mental status, memory, mood,orientation or personalityaltered reflexesweakness, partial weakness involving one side of the body,motor weakness, paraplegia, muscular weakness,decreased strengthaltered vision2. Card i o p u l m o n a r y c a rdiovascular irregularities, irregular heartbeats, palpitationspulmonary i r re g u l a r i t i e s, cough, coughing up blood fromlungs, shortness of breath, respiratory distress, voice change3. Mild Neurological paresthesia, numbness, numbness & tingling,tingling, sensation, twitching4. Pain pain, ache, cramps, discomfort, joint pain,pressure, sharp pain, spasm, stiffness5. Lymphatic / Skin lymphatic irregularities, swelling6. Constitutional / Non-Specific dizzinessskin irregularities, burning of skin, itching, marbling, rashfatigueheadachenausea and/or vomitingchills, perspiration, heaviness, heavy head,lightheadedness, malaise, restlessnessThe distribution of cases by PSI is shown in Figure 3.1-4. Casesfalling into the PSI category of mild neurological were most commonin our sample. The next most common category included caseswith serious neurological symptoms; however, it should be notedthat the definition of serious neurological symptoms is quite broad.Pain-only symptoms represented approximately 20 percent of oursample. Again, it should be remembered the categories are hierarchical,and use of the PSI requires that the case be categorized by the48DAN’s <strong>Report</strong> on Decompression Illness, Diving Fatalities and Project Dive Exploration: 2005 Edition