Acute pulmonary edema from unrecognized high irrigation pressure in hysteroscopy: a report of two cases.

Abstract

After two consecutive patients underwent hysteroscopy that was complicated by pulmonary edema, the pneumatically inflated pressure cuff machine was checked and found that the pressure gauge was in error, with actual pressure being twice that of the recorded number. High irrigation pressures with a seemingly normal amount of irrigation fluid may induce acute pulmonary edema.

Full text

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Case report
Acute pulmonary edema from unrecognized high irrigation
pressure in hysteroscopy: a report of two cases☆
Ming-Hui Hsieh MD (Resident), Ta-Liang Chen MD, PhD (Professor),
Yu-Hua Lin MD (Staff Anesthesiologist),
Chuen-Chau Chang MD, PhD (Assistant Professor),
Chao-Shun Lin MD (Staff Anesthesiologist),
Yuan-Wen Lee MD (Staff Anesthesiologist)⁎
Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan 11031
Received 11 April 2007; revised 23 May 2008; accepted 29 May 2008
Keywords:
Hysteroscopy;
Pulmonary edema
Abstract After two consecutive patients underwent hysteroscopy that was complicated by pulmonary
edema, the pneumatically inflated pressure cuff machine was checked and found that the pressure gauge
was in error, with actual pressure being twice that of the recorded number. High irrigation pressures with
a seemingly normal amount of irrigation fluid may induce acute pulmonary edema.
© 2009 Elsevier Inc. All rights reserved.
1. Introduction
The use of the hysteroscope in modern gynecological
practice continues to develop as a diagnostic and
management tool for intrauterine disease. Complications
arising from hysteroscopy are relatively rare. They occur
more frequently with operative hysteroscopy than with
diagnostic hysteroscopy. One of the reported risks of
hysteroscopy is intravasation of uterine distension fluid.
Volume overload may cause pulmonary edema and
congestive heart failure. Water intoxication may lead to
hyponatremia, hypoosmolarity, and cerebral edema. There-
fore, all possible measures should be taken to prevent it or
else treat it early.
Two cases of acute pulmonary edema from hysteroscopy
with unrecognized high irrigation pressure are presented.
2. Case report
2.1. Case 1
A 40-year-old, 65 kg woman was scheduled to undergo
hysteroscopic surgery for possible intrauterine synechia. She
had a surgical history of myomectomy and her past medical
history was unremarkable. Preoperative laboratory test
showed hemoglobin (Hb) of 14.1 g/dL. Her pre-anesthesia
vital signs were blood pressure (BP) 134/89 mmHg, heart
rate (HR) 80 bpm, and oxygen saturation as determined by
pulse oximetry (SpO2) of 100%.
General anesthesia was induced with intravenous (IV)
administration of fentanyl 50 μg, lidocaine 50 mg, and
propofol 150 mg. Insertion of a Laryngeal Mask Airway
☆Supportwasprovidedsolely from institutionaland departmentsources.
⁎Corresponding author. Tel.: +886 2 2737 2181x8310; fax: +886 2
27367344.
E-mail address: drkevin66@yahoo.com.tw (Y.-W. Lee).
0952-8180/$ – see front matter © 2009 Elsevier Inc. All rights reserved.
doi:10.1016/j.jclinane.2008.05.026
Journal of Clinical Anesthesia (2009) 20, 614–617

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(LMA) was done smoothly after succinylcholine 50 mg IV
was given. Anesthesia was maintained with 2% sevoflurane
in oxygen. Controlled ventilation was provided until
spontaneous respiration resumed, at which time the ventila-
tion mode was changed to manually assisted ventilation for
therest of the case. Surgery was carried out with a monopolar
current resectoscope. Ten percent dextrose solution was used
for uterine distension, and it was infused by compressing the
500 mL bag with a pneumatically inflated pressure cuff
registered at a pressure of 100 mmHg. Hysteroscopy showed
endometrial polyps and intrauterine synechia. During the 40-
minute operative period, the patient received 300 mL of
Ringer’s lactate solution IV. At the end of the procedure, her
SpO2suddenly decreased to 85% on 100% oxygen; the
patient bit down on the LMA, which then could not be
removed. Succinylcholine 50 mg IV was given and
endotracheal intubation was performed quickly on one
attempt. After endotracheal intubation and mechanical
ventilation with 100% oxygen, her SpO2 improved to
100%. However, a large amount of pinkish, frothy sputum
was aspirated from the endotracheal tube and rales were
heard over bilateral lung fields. Chest radiography showed
infiltration typical of pulmonary edema (Fig. 1), and
furosemide 20 mg IV was given. Transvaginal aspiration
of ascitic fluid was performed through the cul de sac by the
surgeon, from which 900 mL of fluid was collected. Arterial
blood gas (ABG) analysis done immediately after intubation
showed pH 7.192, PCO2 56.2 mmHg, PO2 66 mmHg,
sodium 126 mmol/L, potassium 4.3 mmol/L, and glucose
679 g/dL. Another 20 mg of furosemide was given. Urine
output over the next two hours was 450 mL. A second ABG
analysis showed pH 7.264, PCO256.4 mmHg, PO2325
mmHg, sodium 135 mmol/L, and potassium 3.8 mmol/L.
The patient was then transferred from the operating room to
the intensive care unit (ICU) for close observation and care.
Total urine output on that day was 1,390 mL. Chest
radiography showed improvement of the pulmonary
edema, while ABG analysis showed pH 7.423, PCO231.6
mmHg, and PO2122.3 mmHg on the next day. Her trachea
was extubated and she was moved from the ICU to the ward.
One day later, she was discharged home with no sequelae.
2.2. Case 2
A 29-year-old, 54 kg woman was scheduled for
hysteroscopy for dysmenorrhea. Her medical history was
unremarkable. Preoperative laboratory values included Hb
13.6 g/dL. Preoperative vital signs were BP 112/72 mmHg,
HR 61 bpm, and SpO2100%.
General anesthesia was induced with fentanyl 50 μg,
lidocaine 40 mg, and propofol 130 mg. After succinylcholine
40 mg IV was given, the LMA was inserted smoothly.
Anesthesia was maintained with 100% oxygen and 2%
sevoflurane. Ventilation was controlled until spontaneous
respiration resumed. Surgery was performed with a mono-
polar current resectoscope. Ten percent dextrose irrigation
fluid was instilled for uterine distension by compressing the
bag with a pneumatically inflated pressure cuff at a registered
pressure of 75 mmHg. Hysteroscopy showed submucosal
myoma and myomectomy was performed smoothly. During
the 90-minute operative period, 4,000 mL of 10% dextrose
irrigation fluid was used, with 2,000 mL returned, and
400 mL of normal saline solution IV was given. Intraopera-
tive vital signs included BP 80 to 90 mmHg systolic, 40 to
50 mmHg diastolic; and HR 50 to 60 bpm. At the end of
surgery, the LMA was removed smoothly without any
respiratory distress. The patient was then sent to the
postanesthesia care unit where she complained of chest
tightness and coughed out frothy, pinkish sputum. Her SpO2
decreased to 96% with the LMA (O2flow, 6 L/min). Arterial
blood gas analysis showed pH 7.375, PCO237 mmHg, PO2
69 mmHg, sodium 135 mmol/L, potassium 3.3 mmol/L,
glucose N 600 g/dL, and Hb 13.6 g/dL. Chest radiography
showed pulmonary edema (Fig. 2). Furosemide 20 mg,
morphine two mg, and regular insulin 5 units were all
administered IV. Urine output over the next 90 minutes was
600 mL and the patient gradually felt better. At that time,
ABG analysis showed pH 7.349, PCO238.9 mmHg, PO2
115 mmHg, sodium 136 mmol/L, potassium 3.0 mmol/L,
glucose 72 g/dL, and Hb 12.6 g/dL. Oxygen saturation was
99% to 100% with face mask, with oxygen flow of 6 L/min.
Postoperative vital signs were stable and she was transferred
to the ward for postoperative care. On the next day, the
patient was discharged home without problem.
The pneumatically inflated pressure cuff machine was
checked,andthepressuregaugewasfoundtobeinerror,with
the actual pressure being double that of the recorded figures.
Fig. 1
typical of pulmonary edema.
Case 1 chest radiograph showing butterfly infiltration
615Acute pulmonary edema in hysteroscopy

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Therefore, in Case 1, irrigation pressure during hysteroscopy
was 200 mmHg and in Case 2, it was 150 mmHg.
3. Discussion
Hysteroscopic procedures now are the preferred treatment
for dysfunctional uterine bleeding, menorrhagia, and
myoma. Distension of the uterine cavity and establishment
of a continuous intrauterine pressure are basic requirements
for clear visualization of intrauterine structures and efficient
surgical procedures. Low-viscosity fluids are most com-
monly used as distension media for operative hysteroscopy
because of their relative safety and compatibility with the
continuous flow resectoscope [1-4]. Low-viscosity media are
divided into two groups according to their tonicity and
electrolyte content: (1) hypotonic or hypertonic electrolyte-
free media and (2) isotonic electrolyte-containing media [5].
Absorption of a large volume of electrolyte-free, low-
viscosity fluid may result in volume overload with water
intoxication. The absorption may occur by various mechan-
isms, including (1) directly into open vascular structures
during surgical resection, (2) across the walls of the
endometrium, and (3) via the fallopian tubes with absorption
from the peritoneum [6,7]. Volume overload may cause
pulmonary edema, and water intoxication may lead to
hyponatremia, hypoosmolarity, and cerebral edema.
In our two cases, the irrigation fluid used was 10%
dextrose water with irrigation pressure created by compres-
sing the bag with a pneumatically inflated pressure cuff. No
intrauterine pressure monitor or controlled irrigation infu-
sion pump was used during the operation. The irrigation
pressure registered below 100 mmHg. The amount of
absorption of 10% dextrose water was about 1,000 mL in
Case 1 and 2,000 mL in Case 2. However, severe pulmonary
edema with rapid hypotonic fluid overload also was noted in
Case 1. The pulmonary edema was mild in Case 2 even if the
amount of fluid absorption was twice what it should have
been. Therefore, we checked the irrigation pressure system
and found that the pressure gauge was inaccurate and the
actual value was twice the amount necessary. The large
amount of irrigation fluid absorption is a predisposing factor
for acute pulmonary edema in hysteroscopy but irrigation
pressure is also significant. The high irrigation pressure with
a normal amount of irrigation fluid might induce acute
pulmonary edema.
Increased distension pressure, a prolonged surgical
procedure,openvascularchannelsontheendometrialsurface
due to ablation or resection of endometrium, myomas, or
septa, uterine perforation, or cervical laceration all result in
increased risk of fluid overload [8]. Maintaining equilibrium
between women's intrauterine pressures and mean arterial
pressures (MAPs) decreases the risk of absorption of uterine
distension fluid into the vasculature and fluid overload [9]. If
intrauterine pressure was higher than MAP, the amount of
fluid absorption increases. In our two cases, noninvasive BP
valueswererecordedevery 5minutesintraoperatively,butno
intrauterine pressure monitor was used. Independent vari-
ables that might influence intrauterine pressure include (1)
height of the fluid reservoir or the pressure setting of the
pump, (2) type of hysteroscope, (3) degree of cervical
dilatation, and (4) outflow valve condition [10]. Intrauterine
pressure should be limited so as to prevent fluid overload.
McLucas recommends that infusion pressure be limited to 60
cm H2O [11]. However, Istre et al. state that intrauterine
pressureupto100mmHgissafe[12].Devicesusedtocontrol
intrauterine pressure may decrease the amount of fluid
absorptionbutdonoteliminatetheriskofvenousairembolus
[13].
Beside fluid overload, pulmonary edema also may be
attributed to acute airway obstruction at the end of surgery
[14]. In acute airway obstruction, the patient inspires against
an obstruction. Inspiratory effort against airway obstruction
allows the markedly negative intrathoracic pressure to be
transmitted to the perivascular interstitium, thus facilitating
fluid movement into this compartment [15]. Our Case 1
patient developed respiratory distress at the end of the
hysteroscopic procedure after biting down on the LMA.
The possibility of postobstructive pulmonary edema cannot
be ruled out in the patient.
Pulmonary edema is a known complication of hystero-
scopy. The anesthesiologist and gynecologist should main-
tain constant communication about fluid input and output to
Fig. 2
Case 2 chest radiograph showing pulmonary edema.
616M.-H. Hsieh et al.

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prevent complications such as fluid overload. Meticulous
calculation of intraoperative fluid balance and maintenance
of proper intrauterine pressure are equally important, as high
irrigation pressure with a seemingly normal amount of
irrigation fluid may induce acute pulmonary edema.
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