Selected topics
Henry J. Woodford in Essential Geriatrics, 2022
Hyperosmolar hyperglycaemic syndrome (HHS) is a combination of severe hyperglycaemia (30 mmol/L or over), high serum osmolality (320 mOsmol/kg or over) and dehydration (typically 10 to 20% of body weight, or around 10 L water deficit). Patients often present with hypoactive delirium, tachycardia and hypotension. The onset is slow, over several days, which results in an extreme metabolic imbalance. Patients are not, or only mildly, acidotic (serum pH > 7.30, bicarbonate >15). They may be mildly ketotic. The dehydration is caused by osmotic diuresis. HHS is often provoked by inadequate insulin therapy or infection (i.e. pneumonia) plus dehydration. It can be the first presentation of type 2 diabetes. Medications, e.g. oral steroids or atypical antipsychotics, can sometimes precipitate it. Mortality is around 15–20%.140
Falls Risk and Prevention in the Diabetic Patient
Medha N. Munshi, Lewis A. Lipsitz in Geriatric Diabetes, 2007
Dehydration is another physiologic change that predisposes older people to falls and syncope. Older people are particularly vulnerable to dehydration due to impairment in renal salt and water conservation. When exposed to a salt-restricted diet, elderly individuals excrete larger quantities of salt and water than their younger counterparts, leading to volume contraction (21). This is probably due to the reductions in renin and aldosterone concentrations, as well as the elevations in natriuretic peptide associated with aging (22). Consequently, elderly people may rapidly become dehydrated when exposed to fluid restriction, diuretics, or hot weather. The development of diabetes and glucosuria further increases this risk by causing an osmotic diuresis.
Fluids and electrolyte management
Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor in Essentials of Geriatric Neuroanesthesia, 2019
Hypertonic saline 3%–7.5% and mannitol 15% are crystalloid fluids that should be reserved for therapeutic intervention when the intracerebral pressure rises. They dehydrate the intracellular space by virtue of osmosis, and in consequence, expand the plasma volume. The risk of fluid overload is greater with saline because the mannitol also has a diuretic effect. However, the diuresis is of the osmotic kind, which implies that large amounts of extracellular solutes are lost with the urine. This loss later acts to re-fill the intracellular fluid space (“rebound effect”) perhaps in excess of the starting point. Additional sodium administration might help to resolve this problem.
Effect of S-allylcysteine against diabetic nephropathy via inhibition of MEK1/2-ERK1/2-RSK2 signalling pathway in streptozotocin-nicotinamide-induced diabetic rats
Published in Archives of Physiology and Biochemistry, 2023
V. V. Sathibabu Uddandrao, Brahmanaidu Parim, Ravindarnaik Ramavat, Suresh Pothani, S. Vadivukkarasi, Ponmurugan P, Chandrasekaran P, Saravanan Ganapathy
The proposed investigation uncovered that in the DN control group of rats revealed the polyurea, polydipsia, polyphagia and increased faecal production considerably as indications of DM and its associated complications (Wang-Fischer and Garyantes 2018). This can be explained by reality that the renal tubules are unequipped for taking up the entirety of the glucose separated in the glomeruli. The renal discharge of glucose requires drainage of water and delivers an osmotic diuresis. It can cause lack of hydration, following in obscured vision and dry skin, which is because of swaying in the measure of water and glucose in the focal points of the eye during parchedness. Loss of water causes an increase in the serum extremity that supports the thirst place in the hypothalamus (Leib et al. 2016). The adaptive raise in food intake induced by diminution of energy stores in these animals involves the synchronised regulation of various pathways within the hypothalamic arcuate nucleus (ARC), a region of the brain that acts as an integration centre for peripheral signals of energy condition. Under basal circumstances, leptin and insulin are thought to hold back ARC neurons that coexpress neuropeptide Y and agouti generelated protein, peptides that potentially excite food intake (Schwartz et al. 2003). Additionally, it was likewise discovered that SAC fundamentally diminished the diabetic attributes, for example, polyphagia, polydipsia and polyurea which may be because of the counter diabetic capability of the SAC (Saravanan et al. 2009).
Careful use to minimize adverse events of oral antidiabetic medications in the elderly
Published in Expert Opinion on Pharmacotherapy, 2021
Some of adverse events are easily explained by the mechanisms of action, such as genital mycotic infections (related to glucosuria), which are rather common but rarely severe in T2D patients treated with SGLT2is [121]. A retrospective cohort study showed that the use of SGLT2is among women and men aged 66 years or older is associated with increased risk of genital mycotic infections within 30 days (almost x 2.5 compared with DPP–4is), but without associated increased risk of urinary tract infections [128]. Some cases of aggravation of urinary incontinence due to osmotic diuresis have been reported in older patients. Perineal hygiene might reduce genital infections and avoid the development of Fournier disease, a rare necrotizing infection of the external genitalia, perineum, and perianal region, apparently favored by obesity but not specifically by aging [121]. (3) Volume reduction
Hyperosmolar hyperglycemic syndrome in a young boy
Published in Baylor University Medical Center Proceedings, 2019
Archana Reddy, Leland Finley, Shawn Horrall
Unfortunately, there are no prospective data to guide management of HHS in a pediatric patient. It is recommended that pediatric patients with HHS be admitted to the intensive care unit. The goal of fluid therapy is to increase intravascular volume.8 During initial volume repletion, declining serum osmolality may lead to fluid shifts from intravascular to extravascular spaces, and ongoing urinary loss may persist for hours; therefore, ongoing fluid replacement is recommended. A fluid deficit of 12% to 15% of body weight can be assumed in pediatric patients, and a 20 mL/kg normal saline bolus is recommended. Subsequently, 0.45% or 0.75% sodium should be administered over 24 to 48 hours.8–13 Use of hypotonic fluid is preferred, because adult studies suggest that use of isotonic solutions during osmotic diuresis may increase serum sodium concentration, because the urine sodium concentration is hypotonic in comparison to serum.14 Early insulin treatment in HHS is unnecessary and may increase mortality. A rapid decline in glucose concentration with the use of insulin may lead to cerebral edema as well as circulatory compromise. If glucose levels are declining <50 mg/dL/h, insulin therapy may be considered.5 When insulin treatment is begun, continuous administration at 0.025 to 0.05 units/kg/h can be used initially. Boluses are not recommended in the pediatric population. Electrolyte imbalances may be more profound in HHS than in diabetic ketoacidosis, so potassium levels should be checked and replenished immediately.9
Related Knowledge Centers
- Body Water
- Kidney Failure
- Urination
- Urine
- Polyuria
- Renal Physiology
- Kidney
- Fluid Balance
- Drinking
- Heart Failure