Mediastinal tumours
Anju Sahdev, Sarah J. Vinnicombe in Husband & Reznek's Imaging in Oncology, 2020
Thymic carcinoids arise from amine precursor uptake and decarboxylation (APUD) cells of neural crest origin. They are rare, well-differentiated neuroendocrine tumours, more common in men than women with a predilection of 3:1 (48,54). Approximately 50% of thymic carcinoids are hormonally active, usually secreting adrenocorticotropic hormone (ACTH) which may result in Cushing's syndrome (55–57). Thymic carcinoid usually manifests as a large anterior mediastinal mass often with metastases. Occasionally, patients may present with syndrome of inappropriate antidiuretic hormone secretion (SIADH). Underlying multiple endocrine neoplasia (MEN) 1 or MEN 2 is discovered in 20% of patients with a thymic carcinoid. In patients with suspected MEN 1, imaging of the chest, abdomen, and brain should be performed for full staging.
Psychiatric Emergencies Associated with Drug Overdose
R. Thara, Lakshmi Vijayakumar in Emergencies in Psychiatry in Low- and Middle-Income Countries, 2017
The signs and symptoms of an overdose of the newer antidepressants, especially selective serotonin reuptake inhibitors (SSRIs) which have replaced traditional cyclic antidepressants, are altered mentation or sedation, blurred vision, tremor, nausea, vomiting, hypotension, and tachycardia. Most of these are related to excessive serotonergic stimulation. Rarely, seizures, cardiac conduction disturbances, priapism, and the syndrome of inappropriate antidiuretic hormone secretion (SIADH) occur in addition. Overdoses of the newer antidepressants have also been reported to result in death, though rarely. The management of the patient usually consists of supportive care in which intravenous fluids are used for hypotension and benzodiazepines for agitation. Benzodiazepines and barbiturates constitute the first line of therapy for treating seizures (Reilly and Kirk 2007). The treatment of cardiac conduction disturbances is similar to that in an overdose of tricyclic antidepressants.
Perioperative fluids
Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor in Manual of Neuroanesthesia, 2017
Solutions of glucose alone should not be used as maintenance or resuscitative fluid in adult patients presenting for neurosurgery. Being hypotonic with respect to plasma, they are distributed throughout all body compartments, contributing minimally to intravascular volume. The combination of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) associated with surgery, together with excessive use of hypotonic fluid, can result in hyponatremia and, potentially, cerebral edema. Moreover, hyperglycemia is well known to have deleterious effects on traumatic brain injury (TBI), acute ischemic stroke, and subarachnoid hemorrhage (SAH).8–10 Glucose solutions do, however, still retain a place in clinical practice in the treatment of hypoglycemia and ketoacidosis and in fasting protocols for diabetic patients.
Treatment of pemphigus vulgaris: part 1 – current therapies
Published in Expert Review of Clinical Immunology, 2019
Rebecca L. Yanovsky, Michael McLeod, A. Razzaque Ahmed
Cyclophosphamide is myelosuppressive. Hence blood counts must be carefully monitored as pancytopenia can follow cyclophosphamide usage. Another notable side effect is hemorrhagic cystitis, which may be mitigated by adequate hydration and simultaneous 2-Mercaptoethansulfonat-Natrium (Mesna) dosing [7]. Patients may also experience alopecia, hepatitis, or stomatitis. Its teratogenicity can have irreversible effects on fertility. Rarely, reports of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) have been reported [7]. Side effects common to immunosuppressive agents, such as infection, may occur. Similar to other immunosuppressive agents, increased rates of malignancy have been reported with cyclophosphamide use, most notably skin, bladder, and hematopoietic cancers [7]. A total of 10.8% of PV patients treated with cyclophosphamide reported cancer including breast cancer, non-melanoma skin cancer and bladder cancer [60]. These side effects are amplified in patients with poor renal function due to its renal clearance.
Orbital apex syndrome caused by Alternaria species: A novel invasive fungus and new treatment paradigm
Published in Orbit, 2020
Alina Y. Lou, Todd J. Wannemuehler, Paul T. Russell, Behin Barahimi, Rachel K. Sobel
On presentation, the patient’s best-corrected visual acuity was 20/20 in the right eye and 20/400 in the left eye. An afferent pupillary defect was present in the left eye. Intraocular pressures were 14 in both eyes. He was noted to have motility deficits in almost all ductions in the left eye, with ptosis of the left upper eyelid. The patient noted numbness over the left brow and forehead; the corneal sensation was symmetric. A CT scan showed opacification of the left ethmoid air cells with erosion of the left lamina papyracea and extension of inflammation through the medial left orbit to the orbital apex, without evidence of intracranial involvement (Figure 1). Complete blood count (CBC) showed a mild anemia with normal white blood cell count without left shift; absolute neutrophil count (ANC) was normal. Labs were otherwise notable for hyponatremia secondary to syndrome of inappropriate antidiuretic hormone secretion (SIADH). Otolaryngology (ENT) was consulted and performed bedside endoscopy, which revealed evidence of prior partial ethmoidectomy with purulent drainage along the patient’s remaining ethmoid cells. There were otherwise no abnormalities noted.
New drugs on the horizon for cerebral edema: what’s in the clinical development pipeline?
Published in Expert Opinion on Investigational Drugs, 2020
Stephanie M. Robert, Benjamin C. Reeves, Seth L. Alper, Jinwei Zhang, Kristopher T. Kahle
Arginine vasopressin (AVP), also known as antidiuretic hormone (ADH), a peptide produced in the posterior pituitary, has been implicated in intracerebral volume regulation. AVP exerts homeostatic effects via signaling through G protein-coupled receptors expressed on vasculature (V1A), the anterior pituitary gland (V1B/V3), and in renal collecting duct principal cells (V2), conferring integrated control of body fluid volume. Physiologically present in non-pathological CSF, AVP demonstrates an ability to increase brain water content [1], and plasma concentrations can be significantly increased in stroke patients [26]. Indeed, the hyponatremia characteristic of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) is present in a significant proportion of TBI and SAH patients, indirectly exacerbating brain edema [27].
Related Knowledge Centers
- Central Nervous System
- Hypotonic Hyponatremia
- Osmoreceptor
- Vein
- Circulatory System
- Vasopressin
- Posterior Pituitary
- Hypothalamus
- Vasopressin Receptor 2
- Preprohormone