Endocrine diseases and pregnancy
Hung N. Winn, Frank A. Chervenak, Roberto Romero in Clinical Maternal-Fetal Medicine Online, 2021
Cardinal symptoms of DI are polyuria and polydipsia. Polyuria must not be confused with increased frequency of voiding, which is a common symptom of normal pregnancy. Actual polyuria is defined by increased urine volume (more than 2.5liters/24hours), in the absence of glycosuria. A water deprivation test (55), which includes hourly measurement of urine volume and osmolality, body weight, and vital signs, and measurement of plasma sodium every 3–4hours, is the “gold standard” traditional method of establishing the diagnosis of DI, but may be unnecessary if matched serum and urinary sodium, osmolality, and urine volumes reconcile with the clinical history. If a water deprivation test is performed, the patient should be seated or standing throughout the test, since urinary concentrating capacity is compromised during pregnancy by the lateral recumbent position. Water deprivation is achieved by enforced withholding of beverages and food, until a clinical endpoint is reached during the test. Endpoints justifying termination of water deprivation include (i) 3% decrease in baseline (time 0) body weight, (ii) urine osmolality rise <30mOsm/kg/hr for 3consecutive hours, or (iii) plasma sodium > upper limit of normal reference range. Upon attainment of an endpoint, the AVP analog desmopressin (DDAVP) 0.1mL is administered intranasally, and urine osmolality is measured again after 1 to 2hours. In severe CDI, maximal urine osmolality increases more than 50% after administration of DDAVP. In nephrogenic DI, maximal urine osmolality increases significantly less than 50%, and often not at all following administration of DDAVP.
Case 27: Polydipsia and Polyuria
Iqbal Khan in Medical Histories for the MRCP and Final MB, 2018
Biochemistry including Ca may be repeated.Serum lithium levels should be checked as a priority.ECG can be repeated. ST depression and T wave inversion are frequently associated with lithium toxicity.A simultaneous measurement of serum and urine osmolality. If there is any doubt about the cause of the symptoms, a water deprivation test may be carried out (see below).
Endocrinology
Timothy G Barrett, Anthony D Lander, Vin Diwakar in A Paediatric Vade-Mecum, 2002
The water deprivation test is too dangerous for routine use. A simple screening test checks (early-morning) fasting paired plasma and urine samples for sodium and osmolarity. A urine osmolarity > 500 mOsmol/l virtually rules out the diagnosis of DI in the presence of a normal plasma osmolarity. Results suggestive of DI are plasma sodium >145 mmol/l, and plasma osmolarity >295 mOsmol/l, with a urine osmolarity <200 mOsmol/l. If a definitive test is needed, the hypertonic saline test is preferable to a water deprivation test, but should only be performed in a recognized endocrine centre.
Palatability of pediatric formulations: do rats predict aversiveness?
Published in Drug Development and Industrial Pharmacy, 2021
Sandra Simões, Antonio J. Almeida, Joana Marto
Liquid forms definitively improve drug swallowing over conventional tablets and capsules, but formulators quite often face the challenge of masking unpleasant tastes, usually through the use of sweeteners and/or flavors. For conventional solid oral forms, the administration is rapid and unpleasant taste does not remain in the patient´s mouth for a long period. However, in the case of liquid forms the unpleasant taste sensation could be prolonged. Thus, there is a need to improve palatability and, consequently, the acceptability of the forms. Among in vivo approaches to assess the taste of Active Pharmaceutical Ingredients (API), the rodent BATA model has been used with success, with results comparable to human panel data [5,7]. However, such preclinical taste aversion assays are based on long period experiments (maximum session-length of 40 min), where each animal is placed in a lickometer in the presence of sixteen tubes containing liquids both in training or testing days [7] and data acquisition is based on specific software programmes [19]. In this study we followed the water-deprivation period protocol of 22 h previously reported [7] and observed that this time period was suitable to motivate the animals to drink from the only bottle available. No major signs of stress were observed in the animals and they recovered their weight after the rehydration and between experiments (one week interval). No training sessions were needed, since the ‘lickometer’ in this case was merely a conventional maintenance cage.
A novel contrast-induced acute kidney injury mouse model based on low-osmolar contrast medium
Published in Renal Failure, 2022
Jiajia Wu, Jianxiao Shen, Wanpeng Wang, Na Jiang, Haijiao Jin, Xiajing Che, Zhaohui Ni, Yan Fang, Shan Mou
Previous studies have documented contrast media injection solely in male mice is unable to induce AKI. All CI-AKI models require different kinds of pretreatments. The study was divided into three phases (Figure 1). The first phase includes multiple water deprivation pretreatment plans to find whether only water deprivation without furosemide combined with LOCM (iohexol, 10 mL/kg as previously described by other studies [21,23]) and UPHT can induce AKI in mice (Figure 1(A)). The length of water deprivation was according to previous documents [19]. The longest water deprivation time was 72 h. Thus, we chose UPHT + 72 h water deprivation as pretreatment. Sixteen male C57BL/6 mice were assigned to four groups randomly (4 mice/group): (1) control group: normal mice; (2) uninephrectomized group: mice underwent UPHT for four weeks; (3) uninephrectomized + 72 h water deprivation group: water deprivation for 72 h; (4) uninephrectomized + 72 h water deprivation + LOCM administration group: after water deprivation for 72 h, LOCM was injected via tail vein administration. Serum creatinine (SCr) concentrations were detected to evaluate kidney function.
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 a term which, in clinical use, refers to a deficiency in total body water. Whilst no standard means of defining its presence or severity exists (see below), it appears to be both prevalent and costly within the healthcare setting. In 2015, 37% of patients aged over 65 years old admitted to a large UK hospital were dehydrated [1]. Of 370,758 patients in the 2004 US National Hospital Discharge Survey, there were 518,000 hospitalizations primarily due to dehydration, incurring healthcare costs in excess of 5 billion dollars [2]. The problem is not restricted to hospitalized patients, a recent UK study found one in every five older people living in long-term care to be dehydrated (serum osmolality >300 mOsm/kg) and half to be either dehydrated or at risk of becoming so (≥295–300 mOsm/kg) [3]. Furthermore, it has been repeatedly shown that dehydration is associated with increased mortality and morbidity [3–8].