Orbital Compartment Syndrome Following Extracorporeal Support

Journal of Cardiac Surgery

Orbital Compartment Syndrome Following Extracorporeal Support

Journal of Cardiac Surgery

r Fo

Journal:

Manuscript ID: Manuscript Type: Date Submitted by the Author:

Perioperative Management n/a

Brodt, Jessica; University of Miami Miller School of Medicine, Anesthesiology Gologorsky, Daniel; University of Miami Miller School of Medicine, Bascom Palmer Eye Institute Walter, Scott; University of Miami Miller School of Medicine, Bascom Palmer Eye Institute Pham, Si; University of Maryland, Cardiac Surgery Gologorsky, Edward; University of Miami Miller School of Medicine, Department of Anesthesiology

Keywords:

ew

vi

Re

Complete List of Authors:

JOCS-2013-CASR-288.R1

transplant, compartment syndrome, complications, postoperative blindness

ly

On

Page 1 of 21

Title Page Orbital Compartment Syndrome Following Extracorporeal Support Short running title: Postoperative Orbital Compartment Syndrome Authors Jessica Brodt1, MD

r Fo

Daniel Gologorsky2, MD, MBA Scott Walter2, MD

Formatted: Superscript

Department of Anesthesiology, CVT Division, University of Miami Miller

School of Medicine, Miami, FL

ly

2.

Formatted: Superscript

On

1.

Formatted: Superscript

ew

Edward Gologorsky1, MD, FASE

Formatted: Superscript

vi

Si M Pham3, MD, FACS, FAHA

Formatted: Superscript

Re

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Journal of Cardiac Surgery

Bascom Palmer Eye Institute, University of Miami Miller School of

Medicine, Miami, FL 3.

Division of Cardiac Surgery, University of Maryland, Baltimore, MD 21201

Corresponding Author

Journal of Cardiac Surgery

Edward Gologorsky, MD, FASE Department of Anesthesiology University of Miami Miller School of Medicine Jackson Memorial Hospital

r Fo

1611 NW 12th Ave, Room C300 Miami, FL 33136

Re

Email: [email protected] Ph.: 305-585-6970

This paper has not been presented earlier

ly

On

Sources of funding: none

ew

Fax: 305-585-7169

vi

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 21

Page 3 of 21

Abstract

Orbital Compartment Syndrome (OCS) is a rare, catastrophic, but potentially treatable complication. It requires prompt diagnosis and immediate intervention,

r Fo

as critical period for possible functional recovery is very short. This report adds to our understanding of potential mechanisms of perioperative blindness, and suggests extracorporeal circulatory support, systemic inflammatory response and

Re

massive blood and fluid resuscitation as potential risk factors for perioperative OCS.

ew

vi ly

On

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Journal of Cardiac Surgery

Journal of Cardiac Surgery

Introduction A hallmark feature of orbital compartment syndrome (OCS) entails the acute and severe rise of pressure within the ophthalmic orbit that compromises vascular supply to intraorbital structures such as the optic nerve and globe. Similar to

r Fo

other compartment syndromes, OCS requires prompt recognition and immediate intervention, as irreversible loss of vision can take place in as little as 100 minutes (1, 2). However, unlike abdominal or extremity compartment syndromes, OCS is

Re

extremely rare and has primarily been reported in the context of traumatic or iatrogenic retrobulbar hemorrhage. While OCS has been described in patients

vi

who had received massive fluid resuscitation after burn injuries or in those who

ew

had undergone spinal surgery in the prone position (3-5), it has not been previously reported in the cardiothoracic literature. This report describes a case

On

of OCS in a patient who had received massive blood and fluid resuscitation after bilateral lung transplantation with postoperative extracorporeal membrane

ly

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 21

oxygenator (ECMO) support and reviews the literature on this subject.support. Patient consent was obtained for this report.

Page 5 of 21

Patient Profile Case Report A 71-year-old femalewoman (64 kg, 157 cm) was admitted for a bilateral lung transplant for severe interstitial pulmonary fibrosis and pulmonary hypertension.

r Fo

Her past medical history included hypertension, hyperlipidemia, anxiety, hypothyroidism, osteoporosis, and a remote history of cataract extraction with intraocular lens exchange. The lung transplantation was performed via a clamshell

Re

incision with cardiopulmonary bypass. Her intraoperative course was complicated

vi

by delayed graft functional recovery, necessitating postoperative extracorporeal membrane oxygenation (ECMO) support. Severe postoperative bleeding required

ew

a massive transfusion of blood products, including 12 units of packed red blood cells (PRBC), 3000 ml of cell-saver blood, and 18 units of fresh-frozen plasma

On

(FFP). Postoperative transfusion requirements continued to be significant over the first 72 hours of intensive-care unit (ICU) stay, including 26 units of PRBC and

ly

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Journal of Cardiac Surgery

other blood components necessary to treat coagulopathy. Ultimately, she had a positive fluid balance in excess of 6 liters over these first three post-operative days (3200 mL POD-1, 1200 mL POD-2, and 2100mL POD-3).

Journal of Cardiac Surgery

On POD-4, the patient developed a severe and widespread facial edema, a significant left-sided subconjunctival hemorrhage, an inability to close the eyes and bilateral proptosis. Central venous pressure (CVP) was 14mmHg and mean pulmonary arterial (PA) pressure was 23mmHg (non-pulsatile flow due to full ECMO support at 3L/min). Ophthalmologic consultation was immediately

r Fo

obtained. Visual acuity, fields, and motility could not be assessed as the patient was heavily sedated. The right and left pupils were 1.5mm and 2mm, respectively,

Re

and 1 mm and 1.5 mm in bright light. There was a left-sided rapid afferent pupillary defect. The right eye demonstrated proptosis and lagophthalmos when

vi

compared to the left. Anterior segment examination demonstrated moderate

ew

temporal chemosis in the right eye. The left eye was notable for a severe 360° dark subconjunctival hemorrhage. Intraocular pressures were 42 mmHg in the right eye and 71 mmHg in the left eye.

On

The patient was diagnosed with bilateral OCS with left-sided compressive optic

ly

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 21

neuropathy. She underwent an emergency bedside orbital decompression via

bilateral lateral canthotomy with cantholysis. After the procedure, intraocular pressures immediately decreased to 18 and 22 mmHg in the right and left eyes, respectively. On dilated fundus examination, both discs were sharp without pallor or hemorrhages. Retinal vessels were of normal course and caliber, and appeared

Page 7 of 21

well perfused. The maculae were flat and without hemorrhages. Both peripheral retinae were within normal limits. Postoperatively, an emergent non-contrast computerized tomography (CT) scan of the head CT was obtained in order to determine the possible etiology of this

r Fo

patient’s OCS. No retrobulbar hematoma, periorbital or intracranial hemorrhage was identified (Figure 1). The only abnormal finding was mild bilateral proptosis and thickened soft tissues around the left eye, consistent with subconjunctival edema and hemorrhage.

vi

Re

Following orbital decompression, the patient underwent mediastinal reexploration and control of bleeding. Subsequent functional recovery of the

ew

pulmonary grafts allowed the patient to be weaned from ECMO support on POD9. At this time her visual acuity was recorded as 20/25 in the right eye and 20/30

On

in left eye. She was continued on dorzolamide, timolol and latanoprost eye drops, and had maintained normal bilateral intraocular pressure and visual acuity for the remainder of her hospital course.

Discussion

ly

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Journal of Cardiac Surgery

Journal of Cardiac Surgery

The orbit is an enclosed space, containing the globe, extraocular muscles, optic nerve, lacrimal apparatus, and associated vasculature. Surrounded by rigid bony walls on five sides, the orbit is constrained anteriorly by the orbital septum and eyelids that attach to the orbital ridge by the medial and lateral canthal ligaments. Any increase in intraorbital volume initially results in compensatory proptosis of

r Fo

the globe and prolapse of the orbital fat. Once this limited compensatory mechanism is exhausted, further volume expansion results in a severe sustained

Re

increase in pressure within the orbital compartment (6). This rise in pressure generates orbital hypertension and a compartment syndrome that compromises

vi

the optic neurovascular structures. If not immediately addressed, the resulting

ew

vision loss can be irreversible (1, 2, 6), and is thought to be secondary to central retinal artery occlusion, direct compressive optic neuropathy, optic nerve

On

vasculature compression, and ischemic optic neuropathy due to the stretching of nutrient vessels (6, 7). Compromised venous outflow, due to compression of the

ly

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 21

central retinal vein, and soft tissue edema resulting in the compression of the globe, optic nerve and associated vasculature, may also contribute to the

malperfusion of optic neurovascular structures (4, 6). Intraocular pressure (IOP) as measured by tonometry reflects the pressure transmitted to the globe, and is therefore an indirect reflection of intraorbital pressure. IOP has a diurnal variation

Page 9 of 21

and normally varies between 10 to 20 mmHg. It is sensitive to changes in head position, PaCO2, venous drainage, intrathoracic pressure (such as increases realized with a Valsalva maneuver), sympathetic stimulation, and the rate of aqueous humor production and drainage (8).

r Fo

In the patient described in this report, the pathophysiology of OCS can be viewed as a complication of the systemic inflammatory response (associated with delayed graft recovery and ECMO support), and an unintended consequence of massive

Re

transfusion therapy. Risk factors for postoperative visual loss, per the American Society of Anesthesiologists Postoperative Visual Loss Registry, include fluid

vi

accumulation and soft tissue edema, prolonged surgical times (exceeding 6.5

ew

hours), severe blood loss (exceeding 44.7% of estimated blood loss), perioperative anemia and hemodilution (10, 11). However, the predominant listed

On

pathophysiologic mechanisms of perioperative blindness are cortical blindness, ischemic optic neuropathy and retinal vascular occlusion, rather than OCS (11, 12).

ly

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Journal of Cardiac Surgery

Increases in IOP have been noted in patients with severe burns or trauma who undergo massive crystalloid replacement therapy. As a result some centers advocate for the routine measurement of IOP in patients requiring >0.25L/kg of

Journal of Cardiac Surgery

crystalloid resuscitation (3). Although the this described patient received less than 1000 mL of crystalloid in the intraoperative course of lungs transplantationlung transplant, in the postoperative period she required massive blood and blood product transfusion and fluid resuscitation. Potentiated by the systemic inflammatory response, this may have contributed to the development of OCS.

r Fo

OCS is a clinical diagnosis, and a high degree of suspicion is necessary when a

Re

patient presents with changes in vision, periorbital swelling, proptosis, afferent pupillary defects and subconjunctival hemorrhage. Immediate ophthalmologic

vi

consultation should be sought, and an increased IOP consistent with OCS should

ew

prompt an emergency orbital decompression, typically via lateral canthotomy and inferior cantholysis (6, 13). Because the critical period for possible functional

On

recovery is less than 100 minutes, time consuming studies are superfluous. Brevity of the critical period for possible functional recovery (less than 100

ly

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 21

minutes) renders time-consuming confirmatory imaging studies superfluous. Following confirmation of adequate orbital decompression, imaging studies should be obtained to elucidate possible OCS etiologies, such as retrobulbar hematoma, foreign body, tumor or emphysema. Because of the severe coagulopathy and continued systemic anticoagulation for ECMO support,

Page 11 of 21

spontaneous retrobulbar bleeding was suspected as the primary cause of OCS in the described this patient, but this was subsequently excluded by head CT. This case adds to our understanding of pathophysiologic mechanisms of postoperative blindness. Although OCS is not listed as a common cause of

r Fo

perioperative vision loss, similar mechanisms have been hypothesized, but never demonstrated, in the development of ischemic optic neuropathy, the leading cause of perioperative vision loss (9- 12). In contrast to the unclear etiology and

Re

poor prognosis associated with ischemic optic neuropathy, timely recognition and prompt intervention in OCS may result in functional recovery. How many patients

vi

recover, and the rate of functional recovery after OCS remain largely unknown,

ew

probably due to the anecdotal nature of OCS reporting and the absence of large observational studies. This report is the first confirmed clinical observation of

On

OCS in the setting of cardiothoracic surgery. We believe that awareness of this potentially catastrophic but imminently potentially treatable complication of

ly

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Journal of Cardiac Surgery

massive blood transfusion, fluid resuscitation and systemic inflammatory response is important for all clinicians caring for patients undergoing cardiothoracic surgery.

Journal of Cardiac Surgery

References

Hayreh SS, Kolder HE, Weingeist TA. Central retinal artery occlusion and

Re

1.

r Fo

retinal tolerance time. Ophthalmology 1980; 87(1):75-8. 2.

vi

Larsen M, Wieslander S. Acute orbital compartment syndrome after lateral

ew

blow-out fracture effectively relieved by lateral cantholysis. Acta Ophthalmol. Scand. 1999: 77: 232–233 3.

On

Sullivan SR, Ahmadi AJ, Singh CN, Sires BS, Engrav LH, Gibran NS, et al.

Elevated orbital pressure: another untoward effect of massive resuscitation after burn injury. J Trauma 2006;60:72–76 4.

ly

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 12 of 21

Leibovitch I, Casson R, Laforest C, Selva Det al. Ischemic Orbital

Compartment Syndrome as a complication of spinal surgery in the prone position. Ophthalmology 2006;113:105–108

Page 13 of 21

5.

Cullinane DC, Jenkins JM, Reddy S, VanNatta T, Eddy VA, Bass JG, Chen A,

Schwartz M, Lavin P, Morris JA Jret al. Anterior ischemic optic neuropathy: a complication after systemic inflammatory response syndrome. J Trauma. 2000; 48(3):381-6 6.

r Fo

Lima V, Burt B, Leibovitch I, Prabhakaran V, Goldberg R, Selva D (2009).et al.

Orbital Compartment Syndrome: The Ophthalmic Surgical Emergency. Surv Ophthalmol 2009; 54:441-449 7.

Re

Dolman PJ, Glazer LC, Harris GJ, Beatty RL, Massaro BMet al. Mechanisms of

vi

visual loss in severe proptosis. Ophthal Plast Reconstr Surg. 1991; 7:256-60 8.

Murgatroyd H, Bembridge J. Intraocular pressure. Contin Educ Anaesth Crit

Care Pain. 2008; 8(3):100-103

On

9.

ew

Lee LA, Roth S, Posner KL, Cheney FW, Caplan RA, Newman NJ, Domino

KBet al. The American Society of Anesthesiologists Postoperative Visual Loss

ly

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Journal of Cardiac Surgery

Registry: analysis of 93 spine surgery cases with postoperative visual loss. Anesthesiology 2006;105(4):652-9

Journal of Cardiac Surgery

10.

Practice Advisory for Perioperative Visual Loss Associated with Spine

Surgery. An Updated Report by the American Society of Anesthesiologists Task Force on Perioperative Visual Loss Anesthesiology 2012; 116:274–85 11.

Shen AY, Drum M, Roth S. The prevalence of perioperative visual loss in the

r Fo

United States: a 10-year study from 1996 to 2005 of spinal, orthopedic, cardiac, and general surgery. Anesth Analg 2009; 109:1534–45 12.

Roth S. Perioperative visual loss: what do we know, what can we do? Br J

Anaesth 2009; 103: i31–i40

vi

13.

Re

Hatton MP, Rubin PAD. Management of Orbital Compartment Syndrome.

Arch Ophthalmol. 2007;125(3):433-4

ew ly

On

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 21

Page 15 of 21

Title Page Orbital Compartment Syndrome Following Extracorporeal Support Short running title: Postoperative Orbital Compartment Syndrome Authors Jessica Brodt1, MD Daniel Gologorsky2, MD, MBA Scott Walter2, MD Si M Pham3, MD, FACS, FAHA

r Fo

Edward Gologorsky1, MD, FASE

1. Department of Anesthesiology, CVT Division, University of Miami Miller School of Medicine, Miami, FL

Re

2.

Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL

3.

Division of Cardiac Surgery, University of Maryland, Baltimore, MD 21201

Edward Gologorsky, MD, FASE Department of Anesthesiology

Jackson Memorial Hospital

Miami, FL 33136 Email: [email protected] Ph.: 305-585-6970 Fax: 305-585-7169 Sources of funding: none This paper has not been presented earlier

ly

1611 NW 12th Ave, Room C300

On

University of Miami Miller School of Medicine

ew

Corresponding Author

vi

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Journal of Cardiac Surgery

Journal of Cardiac Surgery

Abstract

Orbital Compartment Syndrome (OCS) is a rare, catastrophic, but potentially treatable complication. It requires prompt diagnosis and immediate intervention, as critical period for possible functional recovery is very short. This report adds to our understanding of potential mechanisms of perioperative blindness, and suggests extracorporeal circulatory support, systemic inflammatory response and massive blood and fluid resuscitation as potential risk factors for perioperative OCS.

r Fo

ew

vi

Re ly

On

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 16 of 21

Page 17 of 21

Introduction A hallmark feature of orbital compartment syndrome (OCS) entails the acute and severe rise of pressure within the ophthalmic orbit that compromises vascular supply to intraorbital structures such as the optic nerve and globe. Similar to other compartment syndromes, OCS requires prompt recognition and immediate intervention, as irreversible loss of vision can take place in as little as 100 minutes (1, 2). However, unlike abdominal or extremity compartment syndromes, OCS is extremely rare and has primarily been reported in the context of traumatic or iatrogenic retrobulbar hemorrhage. While OCS has been described in patients who had received massive fluid resuscitation after burn injuries or in those who had undergone spinal surgery in the prone position (3-5), it has not been previously reported in the cardiothoracic literature. This report describes a case of OCS in a patient who had received massive blood and fluid resuscitation after bilateral lung transplantation with postoperative extracorporeal membrane oxygenator (ECMO) support and reviews the literature on this subject. Patient consent was obtained for this report.

r Fo

Patient Profile

Re

A 71-year-old female (64 kg, 157 cm) was admitted for a bilateral lung transplant for severe interstitial pulmonary fibrosis and pulmonary hypertension. Her past medical history included hypertension, hyperlipidemia, anxiety, hypothyroidism, osteoporosis, and a remote history of cataract extraction with intraocular lens exchange. The lung transplantation was performed via a clamshell incision with cardiopulmonary bypass. Her intraoperative course was complicated by delayed graft functional recovery, necessitating postoperative extracorporeal membrane oxygenation (ECMO) support. Severe postoperative bleeding required a massive transfusion of blood products, including 12 units of packed red blood cells (PRBC), 3000 ml of cell-saver blood, and 18 units of fresh-frozen plasma (FFP). Postoperative transfusion requirements continued to be significant over the first 72 hours of intensivecare unit (ICU) stay, including 26 units of PRBC and other blood components necessary to treat coagulopathy. Ultimately, she had a positive fluid balance in excess of 6 liters over these first three postoperative days (3200 mL POD-1, 1200 mL POD-2, and 2100mL POD-3).

ew

vi

ly

On

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Journal of Cardiac Surgery

On POD-4, the patient developed a severe and widespread facial edema, a significant left-sided subconjunctival hemorrhage, an inability to close the eyes and bilateral proptosis. Central venous pressure (CVP) was 14mmHg and mean pulmonary arterial (PA) pressure was 23mmHg (non-pulsatile flow due to full ECMO support at 3L/min). Ophthalmologic consultation was immediately obtained. Visual acuity, fields, and motility could not be assessed as the patient was heavily sedated. The right and left pupils were 1.5mm and 2mm, respectively, and 1 mm and 1.5 mm in bright light. There was a leftsided rapid afferent pupillary defect. The right eye demonstrated proptosis and lagophthalmos when compared to the left. Anterior segment examination demonstrated moderate temporal chemosis in the right eye. The left eye was notable for a severe 360° dark subconjunctival hemorrhage. Intraocular pressures were 42 mmHg in the right eye and 71 mmHg in the left eye.

Journal of Cardiac Surgery

The patient was diagnosed with bilateral OCS with left-sided compressive optic neuropathy. She underwent an emergency bedside orbital decompression via bilateral lateral canthotomy with cantholysis. After the procedure, intraocular pressures immediately decreased to 18 and 22 mmHg in the right and left eyes, respectively. On dilated fundus examination, both discs were sharp without pallor or hemorrhages. Retinal vessels were of normal course and caliber, and appeared well perfused. The maculae were flat and without hemorrhages. Both peripheral retinae were within normal limits. Postoperatively, an emergent non-contrast computerized tomography (CT) scan of the head CT was obtained in order to determine the possible etiology of this patient’s OCS. No retrobulbar hematoma, periorbital or intracranial hemorrhage was identified (Figure 1). The only abnormal finding was mild bilateral proptosis and thickened soft tissues around the left eye, consistent with subconjunctival edema and hemorrhage.

r Fo

Following orbital decompression, the patient underwent mediastinal reexploration and control of bleeding. Subsequent functional recovery of the pulmonary grafts allowed the patient to be weaned from ECMO support on POD-9. At this time her visual acuity was recorded as 20/25 in the right eye and 20/30 in left eye. She was continued on dorzolamide, timolol and latanoprost eye drops, and had maintained normal bilateral intraocular pressure and visual acuity for the remainder of her hospital course.

Discussion

ew

vi

Re

The orbit is an enclosed space, containing the globe, extraocular muscles, optic nerve, lacrimal apparatus, and associated vasculature. Surrounded by rigid bony walls on five sides, the orbit is constrained anteriorly by the orbital septum and eyelids that attach to the orbital ridge by the medial and lateral canthal ligaments. Any increase in intraorbital volume initially results in compensatory proptosis of the globe and prolapse of the orbital fat. Once this limited compensatory mechanism is exhausted, further volume expansion results in a severe sustained increase in pressure within the orbital compartment (6). This rise in pressure generates orbital hypertension and a compartment syndrome that compromises the optic neurovascular structures. If not immediately addressed, the resulting vision loss can be irreversible (1, 2, 6), and is thought to be secondary to central retinal artery occlusion, direct compressive optic neuropathy, optic nerve vasculature compression, and ischemic optic neuropathy due to the stretching of nutrient vessels (6, 7). Compromised venous outflow, due to compression of the central retinal vein, and soft tissue edema resulting in the compression of the globe, optic nerve and associated vasculature, may also contribute to the malperfusion of optic neurovascular structures (4, 6). Intraocular pressure (IOP) as measured by tonometry reflects the pressure transmitted to the globe, and is therefore an indirect reflection of intraorbital pressure. IOP has a diurnal variation and normally varies between 10 to 20 mmHg. It is sensitive to changes in head position, PaCO2, venous drainage, intrathoracic pressure (such as increases realized with a Valsalva maneuver), sympathetic stimulation, and the rate of aqueous humor production and drainage (8).

ly

On

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 18 of 21

Page 19 of 21

In the patient described in this report, the pathophysiology of OCS can be viewed as a complication of the systemic inflammatory response (associated with delayed graft recovery and ECMO support), and an unintended consequence of massive transfusion therapy. Risk factors for postoperative visual loss, per the American Society of Anesthesiologists Postoperative Visual Loss Registry, include fluid accumulation and soft tissue edema, prolonged surgical times (exceeding 6.5 hours), severe blood loss (exceeding 44.7% of estimated blood loss), perioperative anemia and hemodilution (10, 11). However, the predominant listed pathophysiologic mechanisms of perioperative blindness are cortical blindness, ischemic optic neuropathy and retinal vascular occlusion, rather than OCS (11, 12). Increases in IOP have been noted in patients with severe burns or trauma who undergo massive crystalloid replacement therapy. As a result some centers advocate for the routine measurement of IOP in patients requiring >0.25L/kg of crystalloid resuscitation (3). Although this patient received less than 1000 mL of crystalloid in the course of lung transplant, in the postoperative period she required massive blood and blood product transfusion and fluid resuscitation. Potentiated by the systemic inflammatory response, this may have contributed to the development of OCS.

r Fo

OCS is a clinical diagnosis, and a high degree of suspicion is necessary when a patient presents with changes in vision, periorbital swelling, proptosis, afferent pupillary defects and subconjunctival hemorrhage. Immediate ophthalmologic consultation should be sought, and an increased IOP consistent with OCS should prompt an emergency orbital decompression, typically via lateral canthotomy and inferior cantholysis (6, 13). Because the critical period for possible functional recovery is less than 100 minutes, time consuming studies are superfluous. Following confirmation of adequate orbital decompression, imaging studies should be obtained to elucidate possible OCS etiologies, such as retrobulbar hematoma, foreign body, tumor or emphysema. Because of the severe coagulopathy and continued systemic anticoagulation for ECMO support, spontaneous retrobulbar bleeding was suspected as the primary cause of OCS in this patient, but was subsequently excluded by head CT.

ew

vi

Re

On

This case adds to our understanding of pathophysiologic mechanisms of postoperative blindness. Although OCS is not listed as a common cause of perioperative vision loss, similar mechanisms have been hypothesized, but never demonstrated, in the development of ischemic optic neuropathy, the leading cause of perioperative vision loss (9- 12). In contrast to the unclear etiology and poor prognosis associated with ischemic optic neuropathy, timely recognition and prompt intervention in OCS may result in functional recovery. How many patients recover, and the rate of functional recovery after OCS remain largely unknown, probably due to the anecdotal nature of OCS reporting and the absence of large observational studies. We believe that awareness of this potentially catastrophic but potentially treatable complication of massive blood transfusion, fluid resuscitation and systemic inflammatory response is important for all clinicians caring for patients undergoing cardiothoracic surgery.

ly

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Journal of Cardiac Surgery

Journal of Cardiac Surgery

References 1. Hayreh SS, Kolder HE, Weingeist TA. Central retinal artery occlusion and retinal tolerance time. Ophthalmology 1980; 87(1):75-8. 2. Larsen M, Wieslander S. Acute orbital compartment syndrome after lateral blow-out fracture effectively relieved by lateral cantholysis. Acta Ophthalmol. Scand. 1999: 77: 232–233 3. Sullivan SR, Ahmadi AJ, Singh CN, et al. Elevated orbital pressure: another untoward effect of massive resuscitation after burn injury. J Trauma 2006; 60:72–76 4. Leibovitch I, Casson R, Laforest C, et al. Ischemic Orbital Compartment Syndrome as a complication of spinal surgery in the prone position. Ophthalmology 2006;113:105–108

r Fo

5. Cullinane DC, Jenkins JM, Reddy S, et al. Anterior ischemic optic neuropathy: a complication after systemic inflammatory response syndrome. J Trauma. 2000; 48(3):381-6 6. Lima V, Burt B, Leibovitch I, et al. Orbital Compartment Syndrome: The Ophthalmic Surgical Emergency. Surv Ophthalmol 2009; 54:441-449

Re

7. Dolman PJ, Glazer LC, Harris GJ, et al. Mechanisms of visual loss in severe proptosis. Ophthal Plast Reconstr Surg. 1991; 7:256-60

vi

8. Murgatroyd H, Bembridge J. Intraocular pressure. Contin Educ Anaesth Crit Care Pain. 2008; 8(3):100-103

ew

9. Lee LA, Roth S, Posner KL, et al. The American Society of Anesthesiologists Postoperative Visual Loss Registry: analysis of 93 spine surgery cases with postoperative visual loss. Anesthesiology 2006;105(4):652-9

On

10. Practice Advisory for Perioperative Visual Loss Associated with Spine Surgery. An Updated Report by the American Society of Anesthesiologists Task Force on Perioperative Visual Loss Anesthesiology 2012; 116:274–85

ly

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 20 of 21

11. Shen AY, Drum M, Roth S. The prevalence of perioperative visual loss in the United States: a 10year study from 1996 to 2005 of spinal, orthopedic, cardiac, and general surgery. Anesth Analg 2009; 109:1534–45 12. Roth S. Perioperative visual loss: what do we know, what can we do? Br J Anaesth 2009; 103: i31–i40 13. Hatton MP, Rubin PAD. Management of Orbital Compartment Syndrome. Arch Ophthalmol. 2007;125(3):433-4

Page 21 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

Journal of Cardiac Surgery

A

Fo

rR

ev

iew

A

B

On

ly

Figure 1. Non-contrast CT images obtained after bilateral lateral canthotomy and cantholysis. No retrobulbar hemorrhage or papilledema (usually recognized by invagination of the posterior globe margin) is present. There is bilateral proptosis, left (A) more than right (B). Subconjunctival thickening of the left eye (correlating to the edema and hemorrhage) is indicated by the arrow.