Central retinal vein and artery occlusion associated with sildenafil: a case report and review of the literature

BACKGROUND

Sildenafil is a selective phosphodiesterase type 5 inhibitor used for the treatment of erectile dysfunction and pulmonary hypertension. It is available over the counter in many countries. While there have been a few reports of retinal vascular occlusion following sildenafil consumption, most cases have other comorbidities as risk factors for the disease, and the exact causal role of this drug in these conditions remains unclear.

CASE PRESENTATION

We present the case of a healthy 32-year-old Iranian man who developed combined central retinal vein occlusion and retinal artery occlusion following sildenafil exposure. The patient underwent a hypercoagulative state workup for possible underlying risk factors. Additionally, we conducted a literature search on PubMed using the keywords: retinal vein occlusion AND Sildenafil OR Viagra, retinal artery occlusion AND Sildenafil OR Viagra, retinal vascular occlusion AND Sildenafil OR Viagra. To obtain more objective results in the reviews, we employed an adverse drug reaction possibility algorithm. The patient was found to be otherwise healthy, and ancillary tests were unremarkable. A literature review identified seven reports of retinal vascular occlusion following sildenafil use. In most of these cases, the role of sildenafil was not clearly established. To the best of our knowledge, our case achieved the highest score based on the algorithm compared with previous reports.

CONCLUSION

Sildenafil may be associated with severe retinal vascular accidents in otherwise healthy young individuals.

Perioperative Anticoagulation in Patients with Cancer

PURPOSE OF REVIEW

There is a paucity of evidence for managing perioperative anticoagulation in patients with cancer. This review aims to provide clinicians who provide care for patients with cancer an overview of the available information and strategies needed to provide optimal care in a perioperative setting.

RECENT FINDINGS

There is new evidence available around the management of perioperative anticoagulation in patients with cancer. The new literature and guidance were analyzed and summarized in this review. Management of perioperative anticoagulation in individuals with cancer is a challenging clinical dilemma. The approach to managing anticoagulation requires clinicians to review both disease and treatment specific patient factors that can contribute to both thrombotic and bleed risks. A thorough patient-specific assessment is essential in ensuring patients with cancer receive appropriate care in the perioperative setting.

A local-saturation-and-delay MRI method for evaluation of red blood cells aggregation in vivo for tumor-bearing or drug-used rats

Hyperviscosity syndrome (HVS) is a combination of clinical signs and symptoms related to increased blood viscosity. HVS can increase the thrombotic risk by causing a major disturbance to the blood flow, which is usually found in the advanced stages of the tumor. Moreover, some of the drugs used in chemotherapy, such as 5-fluorouracil and erythropoietin, are also capable of causing HVS through their respective pathways. Clinically, the viscosity of a patient's blood sample is measured by a rotary rheometer to estimate the risk of hyperviscosity syndrome. However, the measurement of blood viscosity in vitro is easily affected by storage time, storage environment, and anticoagulants. In addition, the fluid conditions in the rheometer are quite different from those in natural blood vessels, making this method inappropriate for evaluating blood viscosity and its effects in vivo under physiological condition. Herein, we presented a novel magnetic resonance imaging method called local-saturation-and-delay imaging (LSDI). The radial distributions of flow velocity measured by LSDI are consistent with the Ultrasonic (US) method (Spearman correlation coefficient r = 0.990). But the result of LSDI is more stable than US (p < 0.0001). With the LSDI method, we can directly measure the radial distribution of diastolic flow velocity, and further use these data to calculate the whole blood relative viscosity (WBRV) and erythrocyte aggregation trend. It was a strong correlation between the results measured by LSDI and rotary rheometer in the group of rats given erythropoietin. Furthermore, experimental results in glioma rats indicate that LSDI is equivalent to a rheometer as a method for predicting the risk of hyperviscosity syndrome. Therefore, LSDI, as a non-invasive method, can effectively follow the changes in WBRV in rats and avoid the effect of blood sampling during the experiment on the results. In conclusion, LSDI is expected to become a novel method for real-time in vivo recognition of the cancer progression and the influence of drugs on blood viscosity and RBC aggregation.

Cerebral venous thrombosis following an immunoglobulin-E mediated anaphylactic reaction

BACKGROUND

Prothrombotic and pro-inflammatory states are known cerebral venous thrombosis risk factors. To date, two cases of venous thrombotic events after immunoglobulin-E mediated anaphylaxis have been reported. Herein, we describe the first case of cerebral venous thrombosis in close temporal relation with an immunoglobulin-E mediated anaphylactic event.

CASE DESCRIPTION

A 51-year-old female presented with headache, language, and mental disturbance lasting for two days. Two days before the onset, she had undergone a provocative test with deflazacort to study an allergy history; after the test she developed a severe anaphylactic reaction. There were no other comorbidities, and in addition to contraceptive pill, she did not take other medications. On admission the patient was drowsy, with anomic aphasia, inattention and memory impairment. Magnetic Resonance Imaging depicted a left caudate and lenticulo-capsulo-thalamic venous infarct and thrombosis in the deep venous system. The patient was treated with anticoagulation and showed progressive improvement. Neoplastic and pro-thrombotic diseases were excluded.

CONCLUSION

The close temporal association between the anaphylactic reaction and cerebral venous thrombosis suggests that anaphylactic reaction could have been a cerebral venous thrombosis precipitating factor. Immunoglobulin-E have been suggested to have prothrombotic activity by stimulating the release of platelet activation factor, thromboxane A2 and serotonin. This case adds on to the available information on possible cerebral venous thrombosis associated conditions.

Perioperative Anticoagulation Management

Management of anticoagulation in individuals undergoing operative procedures is a complex situation. Each case should be assessed individually with proper risk assessment, monitoring, and plan for perioperative and postoperative anticoagulation. Clinical evidence for the management of these patients is relatively scarce, and clinicians are often assessing each individual case with minimal guidance. This review provides nurses with a summary of available literature on the assessment, laboratory monitoring, timing of adjusting anticoagulation, and bridging prior to procedures. In addition to general perioperative anticoagulation management, this review discusses perioperative management in special populations and provides a summary on principles when anticoagulation should be resumed following a procedure.

Drugs Associated With Ischemic Stroke: A Review for Clinicians

Certain drugs may increase the risk of ischemic stroke (IS). Our goal was to review associations between frequently used drugs and IS. We created an initial list of frequently used drugs to search Pubmed/MEDLINE from 1966 to 2020 and reviewed phase III and IV data, case series, and drug authorities' safety warnings to assess a potential association with IS. Drugs were grouped according to the World Health Organization Anatomical Therapeutic Chemical Classification System. Predefined criteria were applied to establish a level of evidence for an association, from A (high level of evidence of association) to E (high level of evidence of absence of association). In addition, we assessed relative risks and reviewed potential mechanisms of IS facilitation. We assessed 81 drugs or drug classes from 11 World Health Organization Anatomical Therapeutic Chemical Groups. We identified a high level of association for erythropoietin, combined contraceptives, oral estrogen replacement therapy, bevacizumab, tamoxifen, and antipsychotics and a moderate level for ponatinib, nilotinib, darunavir, and gonadotropin-releasing hormone agonists. Drug dose and treatment duration may modify the risk. For a substantial number of drugs, we found no association, and for others, there were insufficient data to categorize risk. We identified a high level of association of IS with a limited number of drugs, a potential association with some, and a lack of data for others. The summarized information may help clinicians to estimate the contribution of a drug to an IS, to better assess drug benefit-risk ratios, and to support decisions about using specific drugs.

Marijuana and thromboembolic events in geriatric trauma patients: The cannabinoids clots correlation!

BACKGROUND

Tetrahydrocannabinol (THC) can alter the coagulation cascade resulting in hypercoagulability. The aim of our study is to evaluate the impact of THC use on thromboembolic complications (TEC) in geriatric trauma patients (GTP).

METHODS

This is a 2017 analysis of the TQIP database including all GTP (age ≥65 years). Patients were stratified based on THC use. Propensity score matching (1:2 ratio) was performed.

RESULTS

A total of 2,835 patients were matched (THC+: 945 and THC-: 1,890). Mean age was 70 ± 6 years, 94% sustained blunt injuries, and median ISS was 22[12-27]. Sixty-two percent of patients received thromboprophylaxis, with median time to initiation of 27 h from admission. Overall, the rate of TEC was 2.1% and mortality was 6.0%. THC + patients had significantly higher rates of TEC compared to THC- patients (3.0% vs. 1.7%; p = 0.01). Rates of DVT (2.2% vs 0.6%, p < 0.01) and PE (1.4% vs 0.4%, p < 0.01) were higher in the THC + group.

CONCLUSION

THC exposure increases the risk of TEC in GTP. Incorporation of THC use into risk assessment protocols merits serious consideration in GTP.