Perioperative visual loss after nonocular surgery

Estimating pulsatile ocular blood volume from intraocular pressure, ocular pulse amplitude, and axial length

The purpose of this study was to develop a method of estimating pulsatile ocular blood volume (POBV) from measurements taken during an ophthalmic exam, including axial length and using a tonometer capable of measuring intraocular pressure (IOP) and ocular pulse amplitude (OPA). Unpublished OPA data from a previous invasive study was used in the derivation, along with central corneal thickness (CCT) and axial length (AL), as well as IOP from the PASCAL dynamic contour tonometer (DCT) and intracameral (ICM) measurements of IOP for 60 cataract patients. Intracameral mean pressure was set to 15, 20, and 35 mmHg (randomized sequence) in the supine position, using a fluid-filled manometer. IOP and OPA measurements were acquired at each manometric setpoint (DCT and ICM simultaneously). In the current study, ocular rigidity (OR) was estimated using a published significant relationship of OR to the natural log of AL in which OR was invasively measured through fluid injection. Friedenwald’s original pressure volume relationship was then used to derive the estimated POBV, delivered to the choroid with each heartbeat as a function of OR, systolic IOP (IOP_sys), diastolic IOP (IOP_dia), and OPA, according to the derived equation POBV = log (IOP_sys/IOP_dia) / OR. Linear regression analyses were performed comparing OPA to OR and calculated POBV at each of the three manometric setpoints. POBV was also compared to OPA/IOP_dia with all data points combined. Significance threshold was p < 0.05. OR estimated from AL showed a significant positive relationship to OPA for both DCT (p < 0.011) and ICM (p < 0.006) at all three manometric pressure setpoints, with a greater slope for lower IOP. Calculated POBV also showed a significant positive relationship to OPA (p < 0.001) at all three setpoints with greater slope at lower IOP, and a significant negative relationship with IOP_dia. In the combined analysis, POBV showed a significant positive relationship to OPA/ IOP_dia (p < 0.001) in both ICM and DCT measurements with R² = 0.9685, and R² = 0.9589, respectively. POBV provides a straight-forward, clinically applicable method to estimate ocular blood supply noninvasively. Higher IOP in combination with lower OPA results in the lowest values of POBV. The simplified ratio, OPA/ IOP_dia, may also provide a useful clinical tool for evaluating changes in ocular blood supply in diseases with a vascular component, such as diabetic retinopathy and normal tension glaucoma. Future studies are warranted.

Multimodal imaging of valsalva petaloid maculopathy secondary to acute laryngospasm and endotracheal intubation

Purpose:

To report the multimodal imaging findings associated to Valsalva retinopathy following acute laryngospasm and endotracheal intubation.

Methods:

Case report and literature review.

Results:

Acute laryngospasm led to pulmonary edema which necessitated endotracheal intubation. Upon extubation the patient complained of bilateral scotomata due to Valsalva retinopathy. Multimodal imaging localizes the precise anatomic site of the intraocular hemorrhages. Petaloid hemorrhages are typical of Henle fiber layer involvement. All the hemorrhages spontaneously cleared without any sequelae.

Conclusion:

Patients with acute laryngospasm and endotracheal intubation may develop Valsalva retinopathy. Multimodal imaging localize the hemorrhages to the specific anatomic site which is important in determining the different management options.

Corneal Abrasions in Total Joint Arthroplasty

Introduction

Corneal abrasion (CA) is the most common ocular complication in patients undergoing nonocular surgery. Corneal abrasions can be caused by a variety of mechanisms, the most common being drying of the cornea due to reduced tear secretions, loss of eyelid reflex, and the loss of pain recognition during surgery. Though CA heals well with eye lubricants, it can result in significant ocular pain and some cases may go on to develop ocular complications. With the current switch to outpatient total joint replacement, CA could potentially lead to discharge delays.

Materials and Methods

We examined the results of a quality improvement project to reduce CA during general anesthesia to determine the rates of CA during hip and knee total joint replacement. We compared rates of CA for 6 months before and 6 months after the intervention.

Results

A total of 670 hip and knee arthroplasty procedures were performed during this period. Two events of CA occurred, one occurred before and one after the intervention to decrease eye injuries. Both incidences occurred during total hip arthroplasty (THA) procedures with the patient in the lateral decubitus position and recovered without long-term deficit.

Discussion

Surgeons and anesthesiologists alike should be cognizant of this avoidable complication and take precaution to protect the eyes during surgery, especially during THA when the patient is placed in the lateral decubitus position.

Conclusion

Corneal abrasion during total joint arthroplasty is a rare complication and is infrequently addressed in the literature. CA is mostly self-limiting, however, but may lead to patient dissatisfaction and to delays if same-day discharge is attempted. Preventative measures and attentive care may help reduce the incidence of CA in patients undergoing total joint arthroplasty. The lateral decubitus position and longer surgeries times are risk factors for CA.

Intraoperative Fluid Management in Patients Undergoing Spine Surgery: A Narrative Review

Fluid management has been widely recognized as an important component of the perioperative care in patients undergoing major procedures including spine surgeries. Patient- and surgery-related factors such as age, length of the surgery, massive intraoperative blood loss, and prone positioning, may impact the intraoperative administration of fluids. In addition, the type of fluid administered may also affect post-operative outcomes. Published literature describing intraoperative fluid management in patients undergoing major spine surgeries is limited and remains controversial. Therefore, we reviewed current literature on intraoperative fluid management and its association with post-operative complications in spine surgery.

Changes of intraocular pressure and ocular perfusion pressure during controlled hypotension in patients undergoing arthroscopic shoulder surgery: A prospective, randomized, controlled study comparing propofol, and desflurane anesthesia

PURPOSE

The aim of the present study is to evaluate the effects of deliberate hypotensive anesthesia on intraocular pressure (IOP) and ocular perfusion pressure (OPP) and compare the effects of propofol total intravenous anesthesia (TIVA) and desflurane anesthesia on IOP and OPP.

METHODS

A total of 50 patients undergoing arthroscopic shoulder surgery in the lateral decubitus position were randomized to receive desflurane or propofol anesthesia. Mean arterial pressure (MAP) was maintained in the range of 60-75 mm Hg during hypotensive anesthesia. IOP was measured using a handheld tonometer at 7 time points: before induction (T1, baseline); immediately after endotracheal intubation (T2); 10 minutes after position change to lateral decubitus (T3); 10, 30, and 50 minutes after the start of hypotensive anesthesia (T4-T6); and at the end of surgery (T7).

RESULTS

MAP decreased about 35% to 38% during hypotensive anesthesia. Compared to baseline values, the IOP at T6 in dependent and non-dependent eyes decreased by 0.43 and 2.74 mm Hg, respectively in desflurane group; 3.61 and 6.05 mm Hg, respectively in the propofol group. IOP of both eyes in the propofol group was significantly lower than in the desflurane group from T2 to T7. OPP of both eyes in both groups was significantly lower than at baseline, except at T2 in the desflurane group. OPP of both eyes in the propofol group was significantly higher than that in the desflurane group at T5 and T6.

CONCLUSIONS

Hypotensive anesthesia reduced IOP and OPP, but propofol TIVA maintained higher OPP than desflurane anesthesia. These findings suggest that propofol TIVA can help mitigate the decrease of OPP during hypotensive anesthesia.

Ischemic optic neuropathy in robotic-assisted gynaecologic surgery: A case report

The study was aimed to present a rare case of who developed non arteritic anterior ischemic optic neuropathy (NAION) following robotic-assisted gynaecologic surgery. A 58-year-old female patient presented with vision loss in right eye after non-complicated robotic-assisted total hysterectomy and bilateral salpingo-oopherectomy. We observed on fundoscopy optic disc edema and splinter hemorrhages at the optic disc edges. Fluorescein angiography showed hypofluorescence of the optic disc in the early phases due to filling delay followed by hyperfluorescence with leakage from disc capillaries in the late phases of the angiogram. From these findings, we diagnosed NAION in the right eye. When NAION was diagnosed, the patient received intravenous methylprednisolone. Topical brimonidin and coenzyme-Q were given. On 1-month follow-up, recovery of visual loss was observed. Here, we present a case of NAION that is an uncommon cause of perioperative visual loss after robotic-assisted gyneacologic surgery.

Perioperative Vision Loss after Non-Ocular Surgery

Perioperative vision loss (POVL) may cause devastating visual morbidity. A prompt anatomical and etiologic diagnosis is paramount to guide management and assess prognosis. Where possible, steps should be undertaken to minimize risk of POVL for vulnerable patients undergoing high-risk procedures. We review the specific risk factors, pathophysiology, and management and prevention strategies for various etiologies of POVL.

Revisiting Postoperative Vision Loss following Non-Ocular Surgery: A Short Review of Etiology and Legal Considerations

Postoperative vision loss (POVL) following non-ocular surgery is a serious complication where the causes are not fully understood. Studies have identified several causes of POVL as well as risk factors and prevention strategies. POVL research is made difficult by the fact that cases are often subject to malpractice claims, resulting in a lack of public access to case reports. This literature review was conducted in order to identify legal issues as a major barrier to studying POVL and address how this affects current knowledge. Informed consent provides an opportunity to overcome legal challenges by reducing malpractice litigation through educating the patient on this outcome. Providing pertinent information regarding POVL during the informed consent process has potential to reduce malpractice claims and increase available clinical information.

The Anesthetic Implications of Aqueous Drainage Devices and Glaucoma: A Report of a Patient Undergoing Urgent Prone Cervical Decompression and Fusion

The pathophysiology of glaucoma and perioperative visual loss is similar. A patient with glaucoma may be at increased risk of perioperative visual loss. For both, goals of management include optimizing ocular perfusion pressure and oxygen delivery. One treatment for refractory glaucoma is an aqueous drainage device; however, there is no published literature on the anesthetic management of patients with these devices. We present the case of a patient with recalcitrant glaucoma treated with an Ahmed Glaucoma Valve who underwent urgent prone surgery. Anesthetic implications of aqueous drainage devices and glaucoma are discussed, and recommendations are made.

Human erythropoietin effect in postoperative visual loss following spine surgery: a case report

Introduction:

Postoperative visual loss (POVL) has become the focus of attention for anesthesiologists as a hallmark of perioperative management in spine surgery. A number of Intraoperative and postoperative factors has been documented but the exact etiology is still unclear. Nowadays, perioperative management and also complete curing of POLV is a big question of ophthalmologists and anesthesiologists. The purpose of this case report is to present a unique experience of complete curing the POLV.

Case Presentation:

Our patient was a 61-year-old man, with 75 kg weight and 180 cm height. The patient had no history of visual impairment except mild cataract in his right eye. The patient had a history of diffuse idiopathic skeletal hyperostosis (DISH). The patient had undergone lumbar surgery in prone position. The operation time was about 6 hours. About 30 minutes after transferring to postanesthesia care unit (PACU), patient was awake and complained of losing his eyesight. There was no vision and light perception in his right eye on primary examination. Urgent ophthalmologist consultation was requested. In ophthalmology examinations, the pupil reflex to light was absent in the right eye. After obtaining patients and his family informed consent, four hours after the operation, 40000 I.U. of recombinant human erythropoietin (rhEPO) was administered for patient in PACU (IV infusion, in 30 min). An ophthalmologist visited him every 6 hours after administration of rhEPO. The patient was transferred to intensive care unit (ICU) one hour later with total visual loss in the right eye. Ophthalmologic examination after the second dose of rhEPO, 30 hours after the operation, reported pupil reflex enhancement and light perception in his right eye. Finally the third dose of rhEPO (40000 I.U., IV infusion) was administered on the third day. Ophthalmologic examination after the third dose of rhEPO, 60 hours after the operation, reported normal pupillary light reflex of the right eye and visual acuity improvement to 20/20. The patient was discharged from hospital after six days, with normal visual acuity and without any new complications except surgical site pain.

Conclusions:

Our case report showed the therapeutic effect of rhEPO in complete curing of POVL. Regarding the side effects of EPO such as thrombogenic effects or mild hemodynamic changes like transient sinus tachycardia during infusion, it seems that beneficial effects of EPO is more than its disadvantages and expenses, for patients with POVL.