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Deceptive bends

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CASE 142 year old maleFirst dive in 6 yearsOwn equipment40 mins at 15 metres in rough seasNO rapid ascentDeveloped cough and SOB 1 hour post divingGradually worsenedAssociated fever/chills


CASE 1- DIAGNOSIS?On examinationHypoxic with sats 92%Patchy opacities on CXRNo pneumothoraxTemp 37.8 degrees



Case 1 Salt water aspiration syndromeFirst described in Royal Navy divers in the 1960sAspiration of a fine mist of seawater from faulty equipment/ flooded demand valveOften a delay to presentationSimilar presentation to a LRTISelf limiting, supportive treatment with oxygenDifferential diagnosis


CASE 254 year old femaleExperienced diverDiving on Swan Wreck (30m dive)NO problems during the diveAt 5m deco stop developed SOBLOC, bought to surface by buddyControlled ascentPMH HTN on B Blocker (variable compliance)


CASE 2 - DIAGNOSIS?Regained consciousness on boatTransferred to EDAlert, normal neuro examClinical signs of APOECG ST depression in V5, V6Troponin mildly elevatedCXR consistent with APO


Case 2 Immersion pulmonary oedemaUsually rapid onset, can occur during any part of the diveLikely due to increase in preloadPatients often have hypertensionIncreased risk with B Blockers? likelihood of recurrenceNormal coronary arteries


CASE 326 year old maleExperienced diverRecent URTIDifficulty equalising throughout diveDiving to 20 metres for 35 minsDeveloped acute onset dizziness whilst lifting tanks back on the boatNo history of rapid ascentNausea and vomitingTinnitus and fullness in right ear


CASE 3 DIAGNOSIS?On examinationVomiting, unable to standHorizontal nystagmusHearing loss in right ear (high frequency)Sensorineural hearing loss


Case 3 Inner ear barotraumaExcessive force with difficulty equalizingDamage to round window (most often), oval window or membrane rupture within labyrinth (Reissners membrane)Perilymph fistula

Differential diagnosis inner ear DCI


Case 4Free diverMultiple free dives to max 10 metres over course of morningDeveloped painful red rash on forearmAbdominal pain, tachycardic, sweaty



Shallow Water Black OutSevere hyperventilation prior to breath-hold diving is the single most dangerous practice in open water, causing blackout during the ascent phase.