Hyperbaric Oxygen Therapy

In Treatment of CO Intoxication

Kun-Lun Huang

Undersea and Hyperbaric Medicine Tri-Service General Hospital

Causes of CO Intoxication

Case 1

F/8, studentHeat bedroom with hot charcoal brazier in winterUnconsciousness at midnightPrimary management at other hospital with oxygen breathingDifficulty in concentratingCompletely recovered after 3 treatments of HBO with 2 ATA 90 min

Case 2

F/63. Visited ER 3 times in 3 months due to headache, nausea, and vomiting. The symptoms improved after I.v. fluid and 2-3 hr ER stay every time. Patient was discharged without a definite diagnosis until an incidental finding of elevated serum CK level. Exposed to incomplete gas combustion when her family was using water heater. Completely recovered after 3 HBO2 treatments No more CO intoxication after relocation of the water heater.

Case 3-5

M/23, M/25, F/23, students/roommates Exposed to incomplete gas combustion of a water heater for more than 3 hours One deep coma with cardiopulmonary distress and two transient unconsciousnessTwo completely recovered after 3 HBO treatment One became vegetable even vigorous HBO treatment for 40 times

Symptoms of CO IntoxicationSymptom Percentage of Patients

Headache 9177Dizziness

NauseaWeakness 53

47Difficulty in concentrating 43Shortness of breath 40Visual changes 25Chest pain 9Loss of consciousness 6Abdominal pain 5Muscle cramping 5

Data are from Ely, 1995; Myers, 1985; and Burney, 1982.

Hypoxic Response Curve

Carbon Monoxide Intoxication

02468

10121416182022

0 25 50 75 100PO2, mmHg

O2

cont

ent,

ml/d

l

Normal

Anemia

CO intoxication

COHb and Clinical FeaturesSeverity COHb Clinical features

Occult < 5% No apparent symptomsMild 5 ~ 10% Decreased exercise tolerance

Moderate 10 ~ 20% Exertional dyspnea, headache, dizzinessImpairment of high cerebral functions

20 ~ 30% Irritability, impaired judgementSevere headache, visual disturbance, nausea、

Severe 30 ~ 40% Cardiac disturbance, muscle weakness40 ~ 50% Fainting, mental confusion

VerySevere

50 ~ 60% Collapse convulsion, paralysis

60 ~ 70%> 70%

Coma, fatal in a few minutesCardiac and respiratory arrest

Kindwall EP, 1994

CO Elimination

0102030405060708090

100

0 5 10 15 20Time, hour

CO

-Hgb

, % o

f ini

tial

100% O2

Room air

HBO

Oxygen Content in Blood on HBO2

0

5

10

15

20

25

30

0 500 1000 1500 2000

PO2, mmHg

Dissolved

Hgb-bound

Total

O2

cont

ent,

ml/d

l

VO2/VB = α × PO2

VO2/VB = 1.39 × Hb × SO2

α × PO2 + 1.39 × Hb × SO2

3 ATA

CO Elimination

Piantadosi et al., NEJM 2002

Indication for HBO2 Therapy

ComaAny period of unconsciousnessCarboxyhemoglobin level > 40% Pregnancy and carboxyhemoglobin level > 15% Sign of cardiac ischemia or arrhythmiaHistory of CAD and carboxyhemoglobin level > 20%Recurrent symptoms for up to 3 wksPersistent symptoms for 4-6 hours with 100% O2

Data are from Myers and Thom, 1994.

HBO2 Therapy for CO Intoxication

Kindwall EP, 1994

HBO2 Treatment FacilityNDMC, Taipei, Taiwan

HBO2 Treatment FacilityNDMC, Taipei, Taiwan

Oxygen Supply

Oxygen Treatment HoodAmron International

Delayed Sequelae of CO intoxication

Hyperbaric Oxygen for Acute Carbon Monoxide Poisoning

Volume 347:1057-1067

October 3, 2002

Lindell K. Weaver, M.D., Ramona O. Hopkins, Ph.D., Karen J. Chan, B.S., Susan Churchill, N.P., C. Gregory Elliott, M.D., Terry P. Clemmer, M.D., James F. Orme, Jr.,

M.D., Frank O. Thomas, M.D., and Alan H. Morris, M.D.

Protocol of HBO2 Therapy

Weaver et al., NEJM 2002

HBO2 Therapy -Pressure profiles

Weaver et al., NEJM 2002

Outcome of HBO2 TherapyWeaver et al., NEJM 2002

Case 5

A 66-year-old femaleLoss of consciousness as she was rescued from a fire environment a few minutes before her arrival ER

Lab Data on ArrivalCBC ABGBiochem.

pH 7.097

PaCO2 53.6

HCO3- 16.2

PaO2 16.2

COHb, % 61.0

Na+ 146

K+ 3.2

AST/ALT 26/

BUN/Cr 12/0.7

Glucose 274

WBC 11500

N/L 90/6

Hct 33.5

Hgb 12.0

Platelet 157000CPK 168

Follow-up ABG AnalysisIntubation

(1 hr)HBO2(6 hr)On arrival

7.315pH

PaCO2

HCO3-

PaO2

COHb, %

7.097

53.6

16.2

16.2

61.0

7.413

33.6 42.0

17.1 25.8

22.6 186.1

23.9 0.2

Protocol of HBO2 Therapy

Weaver et al., NEJM 2002

Dyspnea

Follow-up ABG AnalysisHBO2(6 hr)

2nd HBO2(40 hr)On arrival

7.193pH

PaCO2

HCO3-

PaO2

COHb, %

7.097

53.6

16.2

16.2

61.0

7.413

69.142.0

26.025.8

64.5186.1

0.10.2

Differential DiagnosisRecurrent Dyspnea in 2nd HBO2 Therapy

Complication of HBO2: PneumothoraxAcute MI with LV failureBronchial asthma in acute exacerbationThermal inhalation injury

CXR as Dyspnea Recurred on 3rd Day

Bronchoscopy

Carbonaceous sputum

Final Diagnosis

Acute smoke inhalation with acute carbon monoxide intoxication, thermal lung injury, and delayed respiratory failure

Outcome of Intensive Care

The ventilator was weaned off and endotracheal tube was removed in a week and patient was discharged from the hospital in another two weeks. The pulmonary function test before her discharge revealed normal ventilatoryfunction.

Thank you