Blindness in the Intensive Care Unit: Possible Role for Vasopressors?

Perioperative Blindness in Spine Surgery: A Scoping Literature Review

Perioperative vision loss (POVL) is a devastating surgical complication that impacts both the recovery from surgery and quality of life, most commonly occurring after spine surgery. With rates of spine surgery dramatically increasing, the prevalence of POVL will increase proportionately. This scoping review aims to aggregate the literature pertinent to POVL in spine surgery and consolidate recommendations and preventative measures to reduce the risk of POVL. There are several causes of POVL, and the main contribution following spine surgery is ischemic optic neuropathy (ION). Vision loss often manifests immediately following surgery and is irreversible and severe. Diffusion weighted imaging has recently surfaced as a diagnostic tool to identify ION. There are no effective treatments; therefore, risk stratification for counseling and prevention are vital. Patients undergoing prone surgery of long duration and/or with significant expected blood loss are at greatest risk. Future research is necessary to develop effective treatments.

Blindness following bilateral neck dissection. A case report and review of the literature

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Postoperative vision loss is a rare and devastating complication in head and neck surgery.

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Blindness can also occur after modified radical neck dissection.

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Patients undergoing high-risk procedures should have to be informed that there is a risk of vision loss.

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This complication should be highlighted in the standard declaration of consent.

Introduction

Visual loss is a very rare but dramatic complication of such an indispensable standard procedure in head and neck tumor surgery such as the cervical lymphadenectomy (neck dissection).

Presentation of case

We present a review of the literature and a new case of a postoperative blindness of a 65-year-old man with type 2 diabetes who underwent a unilateral radical neck dissection, a contralateral modified radical neck dissection and a hemimandibulectomy for an oropharyngeal squamous cell carcinoma.

Discussion

By now there have been only 15 clinical cases of total blindness published during the last 60 years. In 13 cases blindness followed a bilateral radical neck dissection whereas in 2 cases blindness occurred after a combined selective and modified radical neck dissection. Ischemia of the optic nerve due to intraoperative hypotension, blood loss and venous congestion were the major etiological aspects of blindness. Perioperative management of differentiated volume and blood administration, blood pressure management and a close postoperative ophthalmological check seem to be of a major importance for prevention and early detection of visual deterioration. Nevertheless, there are no clear predicative factors for blindness after neck dissection and the prognosis is unfavorable.

Conclusion

Even though postoperative vision loss is a rare and devastating complication, this current case and the review of the literature show that it occurs every once in a while following standard operations to the head and neck. Patients undergoing high-risk procedures should have to be informed that there is a slight risk of perioperative vision loss and this should be highlighted in the standard declaration of consent.

Ocular Complications in the Prone Position in the Critical Care Setting: The COVID-19 Pandemic

PURPOSE

Ocular complications are common in the critical care setting but are frequently missed due to the focus on life-saving organ support. The SARS-CoV-2 (COVID-19) pandemic has led to a surge in critical care capacity and prone positioning practices which may increase the risk of ocular complications. This article aims to review all ocular complications associated with prone positioning, with a focus on challenges posed by COVID-19.

MATERIALS AND METHODS

A literature review using keywords of "intensive care", "critical care", "eye care", "ocular disorders", "ophthalmic complications," "coronavirus", "COVID-19," "prone" and "proning" was performed using the electronic databases of PUBMED, EMBASE and CINAHL.

RESULTS

The effects of prone positioning on improving respiratory outcomes in critically unwell patients are well established; however, there is a lack of literature regarding the effects of prone positioning on ocular complications in the critical care setting. Sight-threatening ophthalmic disorders potentiated by proning include ocular surface disease, acute angle closure, ischemic optic neuropathy, orbital compartment syndrome and vascular occlusions.

CONCLUSIONS

COVID-19 patients may be more susceptible to ocular complications with increased proning practices and increasing demand on critical care staff. This review outlines these ocular complications with a focus on preventative and treatment measures to avoid devastating visual outcomes for the patient.

Ophthalmology in Critical Care

Ophthalmic disease encountered in the intensive care unit (ICU) has a wide spectrum of prevalence and severity. Prolonged exposure of the cornea is common and preventable. Trauma, glaucoma, infection, vascular disease, and burns are among the potential causes of vision loss. Patients are predisposed to ocular complications by the ICU environment and critical illness itself. Critically ill patients require prioritization of life-sustaining interventions, and less emphasis is placed on ophthalmic disease, leading to missed opportunities for vision-saving intervention. It is therefore imperative for intensivists, nurses, and other providers to have an increased awareness and understanding of the broad range of ocular conditions potentially seen in the ICU.

Rapidly Sequential Vision Loss From Posterior Ischemic Optic Neuropathy Due to Methicillin-Susceptible Staphylococcus Aureus Bacteremia

A 63-year-old man with a history of high-grade bladder cancer was admitted to the intensive care unit (ICU) with renal failure and methicillin-susceptible Staphylococcus aureus bacteremia originating from his nephrostomy tube. While in the ICU, he had painless, severe loss of vision in the right eye followed by his left eye 12 hours later. Visual acuity was no light perception in each eye. He was anemic, and before each eye lost vision, there was a significant decrease in blood pressure. Dilated fundus examination was normal, and MRI showed hyperintense signal in the bilateral intracanalicular optic nerves on diffusion-weighted imaging and a corresponding low signal on apparent diffusion coefficient imaging. He was diagnosed with bilateral posterior ischemic optic neuropathies (PION), and despite transfusion and improvement in his systemic health, his vision did not recover. PION may be seen in the context of sepsis, and patients with unilateral vision loss have a window for optimization of risk factors if a prompt diagnosis is made.

Postoperative visual loss following dorsal root entry zone rhizotomy: A dreaded complication after a benign procedure

Postoperative visual loss (POVL) is a rare but grave postoperative complication. It has been mainly reported in patients undergoing cardiac and spinal surgeries. Dorsal root entry zone (DREZ) is pain relieving procedure performed in patients with refractory neuropathic pain with minimal complication rate. We present a case of unilateral POVL following DREZ rhizotomy in prone position in a patient having brachial plexus neuropathy. Exact etiology of vision loss was though not clear; hypotension, use of vasopressors and hemodilution may have led to vision loss in this patient. This case report highlights the associated risk factors for development of this hazardous complication.

A Young Man With Severe and Disabling Complications of Septic Shock

A young man had severe septic shock with multiorgan failure due to necrotizing fasciitis caused by group A streptococcus after endoscopic repair of a preperitoneal inguinal hernia. He was treated with surgical exploration and antibiotics and resuscitated with fluids, vasopressors, and inotropic agents. He survived this critical illness, but when he woke up from sedation, his vision was lost in both eyes. Ophthalmological evaluation revealed minimal peripapillary retinal hemorrhages without signs of papillary edema. Visually evoked potentials were negative. Magnetic resonance imaging did not show a cause of the visual damage. The patient had bilateral ischemic optic neuropathy diagnosed. Two weeks later, unilateral sudden deafness also developed. The acquired blindness and hearing loss were unchanged after more than 1 year and seem to be permanent, severely disabling this young survivor of septic shock.

Bilateral posterior ischaemic optic neuropathy after severe diabetic ketoacidosis, cardiopulmonary resuscitation and respiratory failure

A 44-year-old male European with type I diabetes mellitus fell into diabetic ketoacidosis. In the emergency room, he developed an episode of asystole and respiratory failure requiring one cycle of cardiopulmonary resuscitation and extracorporeal membrane oxygenation (ECMO). Waking up 7 days later, he presented a bilateral complete loss of vision. Ophthalmological examination including funduscopy on days 1 and 10, after extubation, showed bilateral large round pupils non-reactive to light and a normal fundus. Neuroimaging studies, including MRI and MRA of the brain, were all within normal limits. A lumbar puncture and comprehensive serological testing excluded an infectious or rheumatic cause. An empirical high-dose intravenous steroid treatment administered for 5 days had no effect on his vision. His eye examination at 1.5 months follow-up showed a normal fundus except for progressive bilateral optic nerve disc pallor, which pointed towards the diagnosis of a posterior ischaemic optic neuropathy.

Uncommon ophthalmologic disorders in intensive care unit patients

Ophthalmologic complications are frequently encountered in intensive care unit (ICU) patients (Grixti et al. Ocul Surf 2012;10(1):26-42). However, eye care is often overlooked in the critical care setting or just limited to the ocular surface because treatment is focussed on the management of organ failures. Lack of awareness about other less common intraocular sight-threatening conditions may have a devastating effect on the patient's vision. To identify specific, frequently missed uncommon ocular disorders in ICU, a literature review using the keywords "Intensive Care," "Eye care," "ITU," "ICU," "Ophthalmological disorders," "Eye disorders" was performed. The databases of CINAHL, PuBMed, EMBASE, and Cochrane library were searched. The higher quality studies are summarized in the table with statements of methodology to clarify the level of evidence. The most prevalent ophthalmologic disorders identified in critically ill subjects include exposure keratopathy, chemosis, and microbial keratitis. In addition, uncommon eye disorders reported in ICU include metastatic endogenous endophthalmitis, acute primary angle closure, ischemic optic neuropathy, pupil abnormalities, vascular occlusions, and rhino-orbital cerebral mucormycosis. Early diagnosis and effective treatment will help to prevent visual loss.

A case report and brief review of the literature on bilateral retinal infarction following cardiopulmonary bypass for coronary artery bypass grafting

Postoperative visual loss is a devastating perioperative complication. The commonest aetiologies are anterior ischaemic optic neuropathy (AION), posterior ischaemic optic neuropathy (PION), and central retinal artery occlusion (CRAO). These appear to be related to certain types of operation, most commonly spinal and cardiac bypass procedures; with the rest divided between: major trauma causing excessive blood loss; head/neck and nasal or sinus surgery; major vascular procedures (aortic aneurysm repair, aorto-bifemoral bypass); general surgery; urology; gynaecology; liposuction; liver transplantation and duration of surgery. The non-surgical risk factors are multifactorial: advanced age, prolonged postoperative anaemia, positioning (supine v prone), alteration of venous drainage of the retina, hypertension, smoking, atherosclerosis, hyperlipidaemia, diabetes, hypercoagulability, hypotension, blood loss and large volume resuscitation. Other important cardiac causes are septic emboli from bacterial endocarditis and emboli caused by atrial myxomata. The majority of AION cases occur during CPB followed by head/neck surgery and prone spine surgery. CPB is used to allow coronary artery bypass grafting on a motionless heart. It has many side-effects and complications associated with its use and we report here a case of bilateral retinal infarction during routine coronary artery bypass grafting in a young male patient with multiple risk factors for developing this complication despite steps to minimise its occurrence.

Amaurosis after spine surgery: survey of the literature and discussion of one case

Postoperative vision loss (POVL) associated with spine surgery is a well known, albeit very rare complication. POVL incidence after spinal surgery ranges from 0.028 to 0.2%; however, due to the increase in number and duration of annual complex spinal operations, the incidence may increase. Origin and pathogenesis of POVL remain frequently unknown. A 73-year-old patient presented with lumbar disc herniation with associated neurological deficits after conservative pre-treatment at a peripheral hospital. Known comorbidities included arterial hypertension, moderate arterial sclerosis, diabetes mellitus type 2, mildly elevated blood lipids and treated prostate gland cancer. During lumbar spine surgery in modified prone position the patient presented with an acute episode of severe hypotension, which required treatment with catecholamines and Trendelenburg positioning. Three hours postoperatively, a visual loss in the right eye occurred, resulting in a complete amaurosis. Antihypertensive medication, arteriosclerosis and intraoperative hypotension are possible causes for the POVL. Intraoperative administration of catecholamines and Trendelenburg positioning for treatment of systemic hypotension might further compromise ocular perfusion. In patients with comorbidities compromising arterial blood pressure, blood circulation and microcirculation, POVL must be considered as a severe postoperative complication. It is recommended to inform patients about such complications and obtain preoperative informed consent regarding POVL. Any recent modification of antihypertensive medication must be reported and analysed for potential intraoperative hemodynamic consequences, prior to spine surgery in prone position.

Perioperative visual loss: what do we know, what can we do?

Perioperative visual loss (POVL), a rare, but devastating complication, can follow non-ocular surgery. Highest rates of visual loss are with cardiac and spine surgery. The main causes of visual loss after non-ocular surgery are retinal vascular occlusion and ischaemic optic neuropathy. This review updates readers on the incidence, suspected risk factors, diagnosis, and treatment of POVL due to these conditions.

Effect of fluid resuscitation on mortality and organ function in experimental sepsis models

INTRODUCTION

Several recent studies have shown that a positive fluid balance in critical illness is associated with worse outcome. We tested the effects of moderate vs. high-volume resuscitation strategies on mortality, systemic and regional blood flows, mitochondrial respiration, and organ function in two experimental sepsis models.

METHODS

48 pigs were randomized to continuous endotoxin infusion, fecal peritonitis, and a control group (n = 16 each), and each group further to two different basal rates of volume supply for 24 hours [moderate-volume (10 ml/kg/h, Ringer's lactate, n = 8); high-volume (15 + 5 ml/kg/h, Ringer's lactate and hydroxyethyl starch (HES), n = 8)], both supplemented by additional volume boli, as guided by urinary output, filling pressures, and responses in stroke volume. Systemic and regional hemodynamics were measured and tissue specimens taken for mitochondrial function assessment and histological analysis.

RESULTS

Mortality in high-volume groups was 87% (peritonitis), 75% (endotoxemia), and 13% (controls). In moderate-volume groups mortality was 50% (peritonitis), 13% (endotoxemia) and 0% (controls). Both septic groups became hyperdynamic. While neither sepsis nor volume resuscitation strategy was associated with altered hepatic or muscle mitochondrial complex I- and II-dependent respiration, non-survivors had lower hepatic complex II-dependent respiratory control ratios (2.6 +/- 0.7, vs. 3.3 +/- 0.9 in survivors; P = 0.01). Histology revealed moderate damage in all organs, colloid plaques in lung tissue of high-volume groups, and severe kidney damage in endotoxin high-volume animals.

CONCLUSIONS

High-volume resuscitation including HES in experimental peritonitis and endotoxemia increased mortality despite better initial hemodynamic stability. This suggests that the strategy of early fluid management influences outcome in sepsis. The high mortality was not associated with reduced mitochondrial complex I- or II-dependent muscle and hepatic respiration.

[Loss of vision after non-ophthalmic surgery: systematic review of the literature on incidence, pathogenesis, treatment and prevention]

BACKGROUND AND GOAL

Postoperative loss of vision is a rare, but devastating complication after non-ocular surgery. It can occur partially or completely and may involve one or both eyes. Since its etiology has not yet been solved, the purpose of this review was to extract potential causes from the case collections reported to propose prophylactic measures.

METHODS

A literature search was performed using the "Pubmed" database of the US National Library of Medicine. MeSH terms and combinations used were: blindness, postoperative complications, ischemic optic neuropathy, not ophthalmological surgical procedures, not neurosurgical procedures. Additionally, the results of the interim analysis of the postoperative visual loss (POVL) registry of the ASA were considered.

RESULTS

The incidence of permanent loss of vision after non-ophthalmologic surgery is reported to be 0.0008%. However, it is elevated up to 0.11% after cardiac and 0.08% after spine surgery. Risk factors seem to be perioperative anemia, arterial hypotension and prone position, but also pre-existing diseases such as arteriosclerosis. Thus hemodynamic stabilization or correction of anemia may be successful in therapy.

CONCLUSION

Patients with pre-existing arteriosclerotic disease scheduled for spine or cardiac surgery, but also for bilateral neck dissection should be informed preoperatively about the rare possibility of POVL. Postoperatively any visual changes should be immediately referred to an ophthalmologist and treated accordingly.

Perioperative visual loss after nonocular surgeries

PURPOSE

To review the current knowledge of persistent visual loss after nonocular surgeries under general anesthesia.

DESIGN

Perspective.

METHODS

Literature review.

RESULTS

The incidence of perioperative visual loss after nonocular surgeries ranges from 0.002% of all surgeries to as high as 0.2% of cardiac and spine surgeries. Any portion of the visual pathways may be involved, from the corneas to the occipital lobes, but the most common site of permanent injury is the optic nerves, and the most often presumed mechanism is ischemia. Anterior ischemic optic neuropathy (AION) is more prevalent among cardiac surgery patients and posterior ischemic optic neuropathy (PION) predominates among those who have had spine and neck procedures. Patients range from age five to 81 years and typically awake with severe bilateral visual loss. Multiple factors have been proposed as risk factors for perioperative ION, including long duration in the prone position, excessive blood loss, hypotension, anemia, hypoxia, excessive fluid replacement, use of vasoconstricting agents, elevated venous pressure, head positioning, and a patient-specific vascular susceptibility that may be anatomic or physiologic. However, the risk factors for any given patient or procedure may vary and are likely multifactorial.

CONCLUSIONS

If, when an ophthalmologist is consulted for a patient with perioperative visual loss, an obvious ocular cause is not apparent, urgent neuroimaging should be obtained to rule out intracranial pathology. Anterior and posterior ION should be considered and careful documentation is essential. Currently, the pathogenesis of perioperative ION remains unclear, and preventive and therapeutic measures remain elusive.

Case series: Monocular visual loss associated with subarachnoid hemorrhage secondary to ruptured intracranial aneurysms

PURPOSE

To describe variations in the presentation of monocular visual loss associated with intracranial aneurysm rupture. The clinical course, possible etiologies and management of visual loss in three patients are described.

CLINICAL FEATURES

The first patient developed Terson's syndrome (vitreal hemorrhage associated with raised intracranial pressure secondary to subarachnoid hemorrhage). Following aneursymal clipping, her postoperative management was conservative and there was no improvement in visual acuity. The second patient underwent surgical clipping of internal carotid aneursysms and sustained visual loss subsequent to surgical dissection and temporary clipping around the optic nerve and anterior choroidal artery. The vessel subsequently thrombosed. Potential contributing factors to visual loss in this case included intraoperative hypotension and anemia. This patient received anti-platelet medications, and experienced subsequent improvement in visual acuity to 6/9. A third patient underwent a right orbito-frontal keyhole craniotomy with the cranial flap retracted across the orbit. Elevated intraocular pressure secondary to external orbital compression may have compromised retinal and choroidal perfusion. This patient also developed vasospasm of both anterior cerebral arteries which resolved partially with papaverine therapy. Hypertension-hypervolemia therapy was instituted, with subsequent partial recovery of visual acuity in her right eye.

CONCLUSION

Perioperative monocular visual loss associated with intracranial aneurysm repair is an infrequent occurrence, and clinical presentations may be quite variable. The primary pathophysiological mechanisms are intraocular hemorrhage and ischemia of ocular structures, including the optic nerve. Early detection, via regular fundoscopic examination and treatment aimed at decreasing intraocular pressure and augmenting ocular perfusion may improve outcomes.

Elevated Orbital Pressure: Another Untoward Effect of Massive Resuscitation after Burn Injury

BACKGROUND

Fluid resuscitation remains a fundamental component of early burn care management. However, recent studies suggest that excessive volumes of resuscitation are being administered. Overresuscitation results in negative sequelae including abdominal and extremity compartment syndromes. Elevated intraocular pressure (IOP) has been described as another potentially devastating effect of massive fluid resuscitation in trauma patients. The orbit, similar to the abdomen and extremity, is a compartment, limited to expansion from edema anteriorly by the eyelids and orbital septum, and posteriorly by the bony orbital walls. The purpose of this study was to review the incidence of elevated IOP in a series of patients with major burn injury.

METHODS

We retrospectively reviewed the charts of 13 consecutive patients admitted to our burn center with burn sizes >25% total body surface area (TBSA). All patients underwent serial IOP measurements for the first 72 hours following admission. Medical records were reviewed for fluid resuscitation volume, IOP measurements, need for canthotomy, and results of canthotomy procedures.

RESULTS

Five of 13 patients had IOP >30 mm Hg and required lateral canthotomy. Canthotomy immediately reduced IOP (p = 0.009). Patients who developed elevated IOP received a significantly larger fluid resuscitation (9.0 cc/kg/%TBSA versus 6.0 cc/kg/%TBSA, p = 0.02). Elevated IOP was significantly associated with delivery of larger fluid resuscitation volume (p = 0.027).

CONCLUSIONS

Massive fluid resuscitation following burn injury can result in orbital compartment syndrome requiring lateral canthotomy. Early diagnosis and treatment of orbital compartment syndrome should be incorporated into the management of patients with major burn injury receiving large fluid resuscitation volume.