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Methods and Equipment for Quality Control of Radiopharmaceuticals
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
Rolf Zijlma, Danique Giesen, Yvette Kruiter, Philip H. Elsinga, Gert Luurtsema
Osmolality is defined as osmoles per liter. For instance, 1 mol NaCl gives 2 osmol. The criterium for human plasma osmolarity is about 285 mosmol/kg. To check if a radiopharmaceutical meets the criteria for osmolality, a freezing point measurement can be performed using an osmometer (Figure 6.9).
Carbamazepine
Published in Stanley R. Resor, Henn Kutt, The Medical Treatment of Epilepsy, 2020
Endocrine disturbances are observed in approximately 9% of patients exposed to CBZ (56). Hyponatremia and low plasma osmolarity may occur. The mechanism is not clear (62). Hyponatremia may lead to weight gain, edema, irritability, and loss of seizure control. The risk of hyponatremia increases with age above 30 years and CBZ serum concentration above 6 pg (62). Large volumes of water should be avoided in patients taking CBZ (63). CBZ-induced water intoxication may be treated with fluid restriction, CBZ dose reduction, or concomitant PHT therapy. In addition, demeclocycline may correct the ADH-like or renal antidiuretic effect of CBZ (64). Switching patients from CBZ to an investigational preparation of CBZ-epoxide may also elevate the sodium. In a single-blind study in which patients were crossed over from CBZ to CBZ-epoxide, serum sodium was significantly higher on the epoxide and two patients who were hyponatremie on CBZ had normal sodiums on the epoxide (65). Oxcarbazepine (see next chapter), a new CBZ derivative, also causes hyponatremia but leads to fewer adverse effects at the onset of treatment and does not have the enzyme-inducing activity of CBZ (66).
Biochemistry
Published in Michael McGhee, A Guide to Laboratory Investigations, 2019
Check serum and plasma osmolality: plasma osmolality 280–290 mOsmol/lmaximum urine osmolality 1,200 mOsmol/lminimum urine osmolality 50 mOsmol/l.
Is a hyperosmolar pump prime for cardiopulmonary bypass a risk factor for postoperative delirium? A double blinded randomised controlled trial
Published in Scandinavian Cardiovascular Journal, 2023
Helena Claesson Lingehall, Yngve Gustafson, Staffan Svenmarker, Micael Appelblad, Fredrik Davidsson, Fredrik Holmner, Alexander Wahba, Birgitta Olofsson
The risk for POD increases by 9% in the study group (OR 1.09, 95% CI 1.03–1.15) on day 1 and by 10% (OR 1.10, 95% CI 1.04–1.16) on day 3 postoperatively. Patients diagnosed with POD had higher plasma osmolality levels, both on days 1 and 3 after surgery. The plasma osmolality increased to 323 (14) mOsmol/kg in the study group vs. 295 (5) mOsmol/kg (p < .001) in the control group at the start of CPB. These differences persisted at weaning: 309 (8) mOsmol/kg vs. 297 (5) mOsmol/kg (p < .001) and on day 1 postoperatively: 294 (9) mOsmol/kg vs. 288 (7) mOsmol/kg (p < .001). Plasma osmolality returned to normal on day 3: 290 (7) mOsmol/kg. All patients in the study group had plasma osmolality levels above 295 mOsmol/kg during CPB. Of note, this was also detected among 63% of the control patients at weaning from bypass. Refer to Figure 2 for a summary.
Mechanisms involved in the cardiovascular effects caused by acute osmotic stimulation in conscious rats
Published in Stress, 2020
Eduardo Albino Trindade Fortaleza, Cristiane Busnardo, Aline Fassini, Ivaldo Jesus Almeida Belém-Filho, Gislaine Almeida-Pereira, José Antunes-Rodrigues, Fernando Morgan Aguiar Corrêa
Changes in plasma osmolality are identified by central and peripheral osmoreceptors (Antunes-Rodrigues, de Castro, Elias, Valenca, & McCann, 2004; Bourque, Oliet, & Richard, 1994; Haberich, 1968). Increases in plasma concentration of NaCl, the main determinant of plasma osmolality and extracellular fluid volume, induce behavioral and neurovegetative adjustments, such as a blood pressure (BP) increase, associated with neurohumoral changes, including sympathetic nervous system activation and vasopressin release (Akins & Bealer, 1990; Antunes-Rodrigues et al., 2004; Crofton & Share, 1989; Garcia-Estan, Carbonell, Garcia-Salom, Salazar, & Quesada, 1989; Onaka & Yagi, 2001; Sharp, Sagar, Hicks, Lowenstein, & Hisanaga, 1991; Weiss, Claassen, Hirai, & Kenney, 1996; Xiong & Hatton, 1996).
A multidisciplinary consensus on dehydration: definitions, diagnostic methods and clinical implications
Published in Annals of Medicine, 2019
Jonathan Lacey, Jo Corbett, Lui Forni, Lee Hooper, Fintan Hughes, Gary Minto, Charlotte Moss, Susanna Price, Greg Whyte, Tom Woodcock, Michael Mythen, Hugh Montgomery
Dehydration is prevalent within the healthcare setting and in the community, and appears to be associated with increased morbidity and mortality. As such, dehydration represents a major challenge to clinicians and poses a significant risk to public health. It has a complex, varying pathophysiology that can lead to non-specific clinical presentations making assessment difficult. The lack of international consensus on definition and diagnosis further complicates the issue. Plasma osmolality, however, represents a valuable, objective surrogate marker of hypertonic dehydration which is underutilized in clinical practice. Furthermore, calculated osmolarity (using the Khajuria–Krahn formula) can be used as an effective screening tool for those at risk and we recommend its incorporation into routine care. Isotonic dehydration is particularly prone to intravascular hypovolaemia, which requires management that is distinct from hypertonic dehydration. The NICE clinical guideline 174 includes recommendations for assessment and management of intravascular hypovolaemia and its use is supported by the authors.