CASE REPORTS
Left-Sided Cardiac Gas Embolism Produced by
Hydrogen Peroxide: Intraoperative Diagnosis Using
Transesophageal Echocardiography
Jose ´ A. Sastre, MBBS, Marı ´a A. Prieto, MBBS, Jose ´ C. Garzo ´n, MBBS, and Clemente Muriel, MD
Anesthesiology Service, University Hospital of Salamanca, Salamanca, Spain
T
he use of transesophageal echocardiography
(TEE) in cardiac surgery permits the evaluation
of cardiac anatomy and function and can also be
used to diagnose intracardiac shunts, disturbances in
valvular function, gas embolism, aortic dissection, and
myocardial ischemia (1). TEE can also be a useful
technique for detecting problems that occur during
the anesthetic or surgical actions.
Hydrogen peroxide (H
2
O
2
) is an oxidizing agent
commonly used in wound cleansing because of its
germicidal action and, in addition, for its action in
bubbling out foreign materials and debris (2). How-
ever, its administration has been associated with gas
embolism in a variety of procedures (3–10).
Case Report
A 78-yr-old, 52-kg woman with mitral and aortic valvular
disease and chronic atrial fibrillation was scheduled for re-
placement of both valves with biological Carpentier protheses.
After a normal postoperative course, the patient returned to the
intensive care unit a week later because of severe anemia and
respiratory insufficiency caused by a massive right hemotho-
rax. Thoracic drainage and blood transfusion were performed,
followed by an exploratory sternotomy. Anesthesia was in-
duced with IV fentanyl 0.15 mg, etomidate 12 mg, and rocu-
ronium bromide 30 mg. Maintenance included fentanyl infu-
sion 4 g · kg
-1
·h
-1
, propofol 4 mg · kg
-1
·h
-1
, rocuronium
bromide 0.5 mg · kg
-1
·h
-1
, and O
2
/N
2
O. Intraoperative mon-
itors included electrocardiogram (ECG) leads II and V
5
with ST
segment analysis, invasive blood pressure, central venous pres-
sure, pulse oximetry, urine output, muscle relaxation, capnog-
raphy (Petco
2
), and TEE by an omniplanar probe (HP Om-
niplana II 21369A and Hewlett-Packard Image Point HX;
Hewlett-Packard, Andover, MA). After sternal incision, blood
and clots were found in the right pleural cavity without an
active source of hemorrhage. Examination of the surgical
wound disclosed a small tear on the anterior surface of the
middle lobe. Before chest closure, the surgeon irrigated the
surgical field with 300 mL 1% H
2
O
2
solution. Immediately, a
ST segment increase of 3.2 mm was observed in ECG leads II,
III and aVF. Coronary vasospasm was suspected. Nitroglycerin
50 g IV was administered, followed by an infusion at a rate of
20 g · kg
-1
· min
-1
. Two minutes later the patient suffered a
severe decrease in blood pressure, bradycardia of 30 bpm, a
decrease in pulse oximetry value from 95% to 89%, and a
decrease in Petco
2
from 34 mm Hg to 30 mm Hg. Atropine
1 mg and ephedrine 10 mg IV were given. Air bubbles were
detected by TEE in left-side structures (Fig. 1, 2). The diagnosis
of gas embolism was strongly suspected. One-hundred percent
oxygen was administrated and the surgical field was flooded
with saline solution. The patient was placed in the Trendelen-
burg position to aid in removing gas from the left ventricle by
placement of a needle into the apex. Just before insertion of the
needle, sudden asystole occurred. Internal cardiac massage
was initiated and epinephrine 1 mg IV was given. Within
seconds, the patient’s ventricular rate increased to 50 bpm and
a small amount of air bubbles exited the left ventricle through
the needle. Epicardial electrodes were connected to a pace-
maker to increase the heart rate to 80 bpm. In a few minutes
ECG abnormalities disappeared and the patient recovered he-
modynamic stability. After chest closure, the patient was trans-
ferred to the intensive care unit and was tracheally extubated
1 h later. Follow-up evaluation showed no evidence of neuro-
logic deficit and no increase of serum cardiac markers. The
subsequent clinical course was favorable and the patient was
discharged from the hospital 15 days later.
Discussion
Gas embolism produced by hydrogen peroxide is an
uncommon surgical complication that can be ex-
plained by a chemical reaction in which hydrogen
peroxide decomposes rapidly as a result of the action
of catalases in blood and tissues, releasing molecular
oxygen and H
2
O:
It has been calculated that 1 mL of H
2
O
2
3% pro-
duces 10 mL of oxygen in the tissues (3).
Air embolism produced by H
2
O
2
has been typically
associated with injection under pressure into closed
and semiclosed body cavities (7–9). However, life-
threatening complications have been reported using
Accepted for publication June 13, 2001.
Address correspondence and reprint requests to Jose ´ Alfonso
Sastre Rinco ´ n, MBBS, Servicio de Anestesiologı ´a, Hospital Univer-
sitario de Salamanca, Paseo de San Vicente, 58-182, 37007,
Salamanca, Spain. Address e-mail to med026221@nacom.es.
©2001 by the International Anesthesia Research Society
1132 Anesth Analg 2001;93:1132–4 0003-2999/01