BAROTRAUMA
AT SEA LEVEL BAROMETRIC PRESSURE = 1 ATM = 760 MMHG = 14.7 PSI
AT 18,000 FT P= ½ ATM
BOYLES LAW = V-P RELATION, CHARLES LAW = T-V
PASCALS LAW—CHANGES IN P APPLIED TO ENCLOSED FLUID (A DIVERS BODY) ARE TRANSMITTED EQUALLY IN ALL DIRECTIONS
HENRY’S LAW—THE AMOUNT OF A GIVEN GAS DISSOLVED IN A LIQUID (AT A GIVEN TEMP) IS DIRECTLY PROPORTIONAL TO THE PARTIAL PRESSURE OF THAT GAS—-NITROGEN IS RIGHT AT THE CRITICAL POINT—THUS “NITROGEN NARCOSIS” NITROGEN COMES OUT OF SOLUTION—”THE BENDS” OR “CAISSON’S DISEASE”
DIVING—NO SUCH THING AS LIMITING YOUR DIVE TO 30 FEET AS THE GREATEST PRESSURE CHANGES ARE NEAR THE SURFACE—-YOU CAN GET BAROTRAUMA AT 4-5 FEET!—THE SAME IS TRUE OF FLYING BUT TO A LESSER EXTENT—CERTAINLY DO NOT FLY AND DIVE WITHING 2 DAYS OF EACH OTHER!
PROPHYLACTIC DECONGESTANTS MAY BE OF SOME VALUE–AFRIN AND PSUEDOPHED
THE DIFFERENCE IN PRESSURE FROM THE NP AND THE ME—60 MMMHG “AURAL FULLNESS”—-90 MMHG “ETT LOCKS AND CANNOT EQUALIZE”—–100 MMHG “THE TM RUPTURES”
THIS CAN GIVE YOU VERTIGO FOR 3 REASONS—CALORIC, ALTERNOBARIC, OR PLF
EAR PLUG USE IS DANGEROUS—CANAL SQUEEZE WHILE DIVING AND REVERSE SQUEEZE WHILE ASCENDING—-INCREASED RISK OF TM OR OTIC CAPSULE RUPTURE
ALTERNOBARIC VERTIGO MAY HAPPEN WITH > 45 MMGH DIFFERENCE IN THE EARS
CAN ALSO RARELY GET BAROPARESIS OF THE FACIAL NERVE
DIVING AND FLYING ARE VERY CONTROVERSIAL ISSUES—ESPECIALLY AFTER STAPES SURGERY
ME BAROTRAUMA USUALLY PRECEDES INNER EAR BARO TRAUMA—-ME HEMMORAGE (HEMOTYMPANUM), INNER EAR HEMORRAGE (USUALLY BASAL TURN OF THE COCHLEA), RUPTURE OF REISSNER’S MEMBRANE (MIXTURE OF ENDO AND PERILYMPH), PLF, MIXED INJURY