The Corrected Serum Sodium Concentration in Hyperglycemic Crises: Computation and Clinical Applications.

In hyperglycemia, hypertonicity results from solute (glucose) gain and loss of water in excess of sodium plus potassium through osmotic diuresis. Patients with stage 5 chronic kidney disease (CKD) and hyperglycemia have minimal or no osmotic diuresis; patients with preserved renal function and diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS) have often large osmotic diuresis. Hypertonicity from glucose gain is reversed with normalization of serum glucose ([Glu]); hypertonicity due to osmotic diuresis requires infusion of hypotonic solutions. Prediction of the serum sodium after [Glu] normalization (the corrected [Na]) estimates the part of hypertonicity caused by osmotic diuresis. Theoretical methods calculating the corrected [Na] and clinical reports allowing its calculation were reviewed. Corrected [Na] was computed separately in reports of DKA, HHS and hyperglycemia in CKD stage 5. The theoretical prediction of [Na] increase by 1.6 mmol/L per 5.6 mmol/L decrease in [Glu] in most clinical settings, except in extreme hyperglycemia or profound hypervolemia, was supported by studies of hyperglycemia in CKD stage 5 treated only with insulin. Mean corrected [Na] was 139.0 mmol/L in 772 hyperglycemic episodes in CKD stage 5 patients. In patients with preserved renal function, mean corrected [Na] was within the eunatremic range (141.1 mmol/L) in 7,812 DKA cases, and in the range of severe hypernatremia (160.8 mmol/L) in 755 cases of HHS. However, in DKA corrected [Na] was in the hypernatremic range in several reports and rose during treatment with adverse neurological consequences in other reports. The corrected [Na], computed as [Na] increase by 1.6 mmol/L per 5.6 mmol/L decrease in [Glu], provides a reasonable estimate of the degree of hypertonicity due to losses of hypotonic fluids through osmotic diuresis at presentation of DKH or HHS and should guide the tonicity of replacement solutions. However, the corrected [Na] may change during treatment because of ongoing fluid losses and should be monitored during treatment.

Long Term Exposure to Tenofovir Disoproxil Fumarate-Containing Antiretroviral Therapy Is Associated with Renal Impairment in an African Cohort of HIV-Infected Adults.

OBJECTIVES AND METHOD: There are growing concerns of tenofovir disoproxil fumarate (TDF)-associated renal toxicity. We evaluated the effect of long-term TDF exposure on renal function in a cohort of HIV-1-infected Nigerians between 2006 and 2015. Multivariate logistic regression was used to identify predictors of renal impairment at different time over 144 weeks of antiretroviral therapy (ART). RESULTS: Data of 4897 patients, median age 42 years (interquartile range: 36-49), and 61% females were analyzed. The prevalence of renal impairment increased from 10% at week 24 to 45% at 144 weeks in TDF-exposed participants compared to an increase from 8% at 24 weeks to 14% at 144 weeks in TDF-unexposed participants. Tenofovir disoproxil fumarate exposure predicted the risk of renal impairment at 144 weeks of ART (odds ratio: 2.36; 95% confidence interval: 1.28-4.34). CONCLUSION: Long-term exposure to TDF-based ART significantly increases the likelihood of renal impairment. The continued use of TDF-based regimen in our setting should be reviewed. We recommend the urgent introduction of tenofovir alafenamide-based regimen in the HIV treatment guidelines of Nigeria and other resource-limited countries.

Principles of quantitative water and electrolyte replacement of losses from osmotic diuresis.

Osmotic diuresis results from urine loss of large amounts of solutes distributed either in total body water or in the extracellular compartment. Replacement solutions should reflect the volume and monovalent cation (sodium and potassium) content of the fluid lost. Whereas the volume of the solutions used to replace losses that occurred prior to the diagnosis of osmotic diuresis is guided by the clinical picture, the composition of these solutions is predicated on serum sodium concentration and urinary sodium and potassium concentrations at presentation. Water loss is relatively greater than the loss of sodium plus potassium leading to hypernatremia which is seen routinely when the solute responsible for osmotic diuresis (e.g., urea) is distributed in body water. Solutes distributed in the extracellular compartment (e.g., glucose or mannitol) cause, in addition to osmotic diuresis, fluid transfer from the intracellular into the extracellular compartment with concomitant dilution of serum sodium. Serum sodium concentration corrected to euglycemia should be substituted for actual serum sodium concentration when calculating the composition of the replacement solutions in hyperglycemic patients. While the patient is monitored during treatment, the calculation of the volume and composition of the replacement solutions for losses of water, sodium and potassium from ongoing osmotic diuresis should be based directly on measurements of urine volume and urine sodium and potassium concentrations and not by means of any predictive formulas. Monitoring of clinical status, serum sodium, potassium, glucose, other relevant laboratory values, urine volume, and urine sodium and potassium concentrations during treatment of severe osmotic diuresis is of critical importance.

Fluid balance concepts in medicine: Principles and practice.

The regulation of body fluid balance is a key concern in health and disease and comprises three concepts. The first concept pertains to the relationship between total body water (TBW) and total effective solute and is expressed in terms of the tonicity of the body fluids. Disturbances in tonicity are the main factor responsible for changes in cell volume, which can critically affect brain cell function and survival. Solutes distributed almost exclusively in the extracellular compartment (mainly sodium salts) and in the intracellular compartment (mainly potassium salts) contribute to tonicity, while solutes distributed in TBW have no effect on tonicity. The second body fluid balance concept relates to the regulation and measurement of abnormalities of sodium salt balance and extracellular volume. Estimation of extracellular volume is more complex and error prone than measurement of TBW. A key function of extracellular volume, which is defined as the effective arterial blood volume (EABV), is to ensure adequate perfusion of cells and organs. Other factors, including cardiac output, total and regional capacity of both arteries and veins, Starling forces in the capillaries, and gravity also affect the EABV. Collectively, these factors interact closely with extracellular volume and some of them undergo substantial changes in certain acute and chronic severe illnesses. Their changes result not only in extracellular volume expansion, but in the need for a larger extracellular volume compared with that of healthy individuals. Assessing extracellular volume in severe illness is challenging because the estimates of this volume by commonly used methods are prone to large errors in many illnesses. In addition, the optimal extracellular volume may vary from illness to illness, is only partially based on volume measurements by traditional methods, and has not been determined for each illness. Further research is needed to determine optimal extracellular volume levels in several illnesses. For these reasons, extracellular volume in severe illness merits a separate third concept of body fluid balance.

Secondary hyperparathyroidism among Nigerians with chronic kidney disease.

BACKROUND: Secondary hyperparathyroidism (SHPT) is a manifestation of chronic kidney disease mineral bone disorder (CKD-MBD). SHPT is common in patients with chronic kidney disease (CKD) and is associated with significant morbidity and mortality. METHODS: A cross- sectional descriptive study involving 230 patients with CKD. RESULTS: The mean age of the study population was 44.17±15.24 years. The median intact parathyroid hormone and alkaline phosphatase levels were 96pg/ml (range 4-953pg/ml) and 88 iu/l (range 10-800 iu/l) respectively. The mean (with standard deviation) calcium, serum phosphate, calcium phosphate product and haemoglobin levels were 2.22±0.29mmol/l, 1.8±0.62mmol/l, 3.94±1.42mmol2/l2 and 9.90±1.87g/dl respectively. Majority of patients had advanced CKD with 70.3% of patients in stage G5. The prevalence rates of SHPT, hypocalcaemia, hyperphosphataemia, elevated alkaline phosphatase and elevated calcium phosphate product were 55.2%, 34.8%, 66.1%, 42.2% and 25.2% respectively.Univariate analysis revealed that SHPT was associated with hypocalcaemia, hyperphosphataemia, elevated alkaline phosphatase, proteinuria, anaemia, hypertension, left ventricular hypertrophy and stage of kidney disease; being worse with advancing kidney disease. Independently associated with SHPT were hypocalcaemia (OR=4.84), hyperphosphataemia (OR=3.06), and elevated alkaline phosphatase (OR=2.04). CONCLUSION: The prevalence of SHPT in CKD is high, occurs early and is independently associated with hypocalcaemia, hyperphosphataemia and elevated alkaline phosphatase. The prevalence of SHPT also increases with worsening renal function.

Obesity and obstructive sleep apnea risk among Nigerians.

BACKGROUND: The contribution of obesity to obstructive sleep apnea (OSA) is poorly described in Nigeria. We aimed to compare OSA risk between obese and nonobese adults in urban Nigeria. MATERIALS AND METHODS: An analytic cross-sectional study was conducted. Participants were interviewed using the World Health Organization Non-Communicable Disease questionnaire. OSA risk assessment was performed using the STOP-BANG questionnaire. A total score of ≥3 on the STOP-BANG questionnaire indicated OSA risk, whereas a score ≥5 indicated high OSA risk. Obesity was defined as body mass index (BMI) >30 kg/m2. Relationship between obesity and OSA was tested using chi-square and logistic regression models used to control for confounding factors. RESULTS: There were 744 respondents, with a mean age of 44 (standard deviation 10) years. A total of 206 [27.7%, 95% confidence interval (CI) 24.46-30.9] respondents were obese (BMI ≥30 kg/m2). A total of 307 (41.3%, 95% CI 37.7-44.9) respondents scored ≥3 on the STOP-BANG questionnaire, whereas 37 (4.9%, 95% CI 3.6-6.7) scored ≥5. More number of obese than nonobese [57.8% (119/206) versus 34.9% (188/538)] respondents met the criteria for OSA risk (P < 0.001). Similarly, more obese persons [10.3% (21/206)] met the criteria for high-risk OSA compared to the nonobese [3% (16/538)]; P < 0.001. In logistic regression models adjusted for cigarette smoking and alcohol consumption, the odds for OSA risk was 15.76 (95% CI 7.44-33.9) in persons with BMI >35 kg/m2 compared to those with a BMI range of 18.5-24.99. CONCLUSION: Obesity and OSA may be more prevalent in Nigeria than previously predicted. Obesity independently increased OSA risk in this population.

A survey of non-communicable diseases and their risk factors among university employees: a single institutional study.

BACKGROUND: The incidence of non-communicable diseases (NCDs) is rising globally, with its attendant morbidity and mortality, especially in developing countries. This study evaluated the prevalence of NCDs and their risk factors among members of a university community. METHODS: All employees of the university were invited to the University health clinic for screening, using the World Health Organisation's STEPwise approach to NCDs. RESULTS: A total of 883 (521; 59.0% males) employees with a mean age of 44 ± 10 years were studied. The median (IQR) number of NCD risk factors was three (two to three) per participant. The most common NCD risk factors were inadequate intake of fruit and vegetables (94.6%; 95% CI: 92.8-95.9), physical inactivity (77.8%; 95% CI: 74.9-80.5%) and dyslipidaemia (51.8%; 95% CI: 48.4-51.6%). Others included obesity (26.7%; 95% CI: 23.9-29.8%), alcohol use (24.0%; 95% CI: 21.3-27.0%) and cigarette smoking (2.9%; 95% CI: 2.0-4.3). Hypertension was the most common NCD (48.5%; 95% CI: 45.1-51.8%), followed by chronic kidney disease (13.6%; 95% CI: 11.4-16.1) and diabetes mellitus (8.0%; 95% CI: 6.4-10.1). There was no gender-specific difference in the prevalence of NCDs. CONCLUSION: This study identified that NCDs and their modifiable risk factors are highly prevalent in this community. Workplace policy to support the adoption of healthy living is needed.

Prevalence and predictors of severe menopause symptoms among HIV-positive and -negative Nigerian women.

We compared the prevalence of menopause symptoms between women living with HIV to their HIV-negative peers and determined predictors of severe menopause symptoms in Jos, Nigeria. This descriptive cross-sectional study included 714 women aged 40-80 years. We compared prevalence and severity of menopause symptoms using the menopause rating scale (MRS). Logistic regression analysis was used to determine the predictors of severe symptoms. Six-hundred and seven (85.0%) were HIV-positive, with a mean duration of infection of 5.6 ± 2.7 years. The mean age of the cohort was 46 ± 5 years. The most prevalent menopause symptoms were hot flushes (67.2%), joint and muscle discomfort (66.2%), physical/mental exhaustion (65.3%), heart discomfort (60.4%), and anxiety (56.4%). The median MRS score was higher for HIV-positive compared to HIV-negative women (p = 0.01). Factors associated with severe menopause symptoms included HIV-positive status (aOR: 3.01, 95% CI: 1.20-7.54) and history of cigarette smoking (aOR: 4.18, 95% CI: 1.31-13.26). Being married (aOR: 0.49, 95% CI: 0.32-0.77), premenopausal (aOR: 0.60, 95% CI: 0.39-0.94), and self-reporting good quality of life (aOR: 0.62. 95% CI: 0.39-0.98) were protective against severe menopause symptoms. We found HIV infection, cigarette smoking, quality of life, and stage of the menopause transition to be associated with severe menopause symptoms. As HIV-positive populations are aging, additional attention should be given to the reproductive health of these women.

Sexual dysfunction and its determinants among women infected with HIV.

OBJECTIVE: To describe the prevalence of female sexual dysfunction (FSD) and its determinants among women with HIV infection enrolled for care and treatment in an ambulatory care setting. METHODS: A questionnaire-based cross-sectional survey was conducted among women attending the HIV clinic of Jos University Teaching Hospital, Nigeria, between March 2013 and February 2014. The self-administered Female Sexual Function Index (FSFI) was used to assess FSD; a score of less than 26.55 indicated FSD. Pearson coefficient was used to assess interdomain correlation, and multiple linear regression was used to identify factors associated with FSD. RESULTS: Among 370 participants, 330 (89.2%, 95% confidence interval [CI] 85.6%-92.2%) had FSD. The overall median FSFI score was 19.2 (interquartile range [IQR] 6.4-23.9). The arousal domain had the lowest subscore (median 2.7, IQR 0.0-3.6). The highest interdomain correlations were between lubrication and orgasm (r=0.87), arousal and lubrication (r=0.84), and arousal and orgasm (r=0.81) domains. Satisfactory health (ß=3.34, 95% CI 1.16-5.52) and history of alcohol use (ß=2.38, 95% CI 0.28-4.47) were independently associated with FSD. CONCLUSION: FSD was prevalent among women with HIV infection. Care providers need to routinely address FSD as part of a comprehensive care package in the study setting.

Hypertonicity: Clinical entities, manifestations and treatment.

Hypertonicity causes severe clinical manifestations and is associated with mortality and severe short-term and long-term neurological sequelae. The main clinical syndromes of hypertonicity are hypernatremia and hyperglycemia. Hypernatremia results from relative excess of body sodium over body water. Loss of water in excess of intake, gain of sodium salts in excess of losses or a combination of the two are the main mechanisms of hypernatremia. Hypernatremia can be hypervolemic, euvolemic or hypovolemic. The management of hypernatremia addresses both a quantitative replacement of water and, if present, sodium deficit, and correction of the underlying pathophysiologic process that led to hypernatremia. Hypertonicity in hyperglycemia has two components, solute gain secondary to glucose accumulation in the extracellular compartment and water loss through hyperglycemic osmotic diuresis in excess of the losses of sodium and potassium. Differentiating between these two components of hypertonicity has major therapeutic implications because the first component will be reversed simply by normalization of serum glucose concentration while the second component will require hypotonic fluid replacement. An estimate of the magnitude of the relative water deficit secondary to osmotic diuresis is obtained by the corrected sodium concentration, which represents a calculated value of the serum sodium concentration that would result from reduction of the serum glucose concentration to a normal level.

An Audit of Perineal Trauma and Vertical Transmisson Of HIV.

Restrictive episiotomy is recommended for the prevention of vertical transmission of HIV. The study compared the frequency of episiotomy use and the occurrence of perineal tears; and related factors in HIV positive and HIV negative women and to assess their effect on Mother-to-child transmission (MTCT) of HIV. A total of 110 HIV positive and 134 HIV negative parturients were enrolled in the study. The incidence of episiotomy was more in the HIV negative group (p=0.0000) while that of perineal tear was not affected by HIV status (p=0.17). The rate of episiotomy was significantly affected by primigravidity in HIV negative subjects (OR= 0.032, 95% CI 0.0072-0.13). The rate of perineal tear was significantly affected by primigravidity in HIV positive subjects (OR=8.55, 95% CI 1.91-38.7) and multigravidity in HIV negative subjects (OR= 0.030, 95% CI 0.133-0.71). Gestational age and mean birth weight had no effect on the rate of episiotomy (p value =0.57 and 0.30) and perineal tear (p value= 0.79 and 0.061). There was no mother-to-child HIV transmission. Episiotomies should be given when needed irrespective of HIV status because of the risk of consequent perineal tear and with HAART the risk of MTCT from perineal trauma is minimal.

Sexual Functioning and Health-related Quality of Life in Men.

BACKGROUND: Although erectile dysfunction (ED) is common, little is known about the impact of ED on the quality of life (QoL) among African men. MATERIALS AND METHODS: We used the International Index of Erectile Function (IIEF) to evaluate ED and the WONCA charts to assess QoL among employees of a university. RESULTS: A total of 508 men with a mean age of 43 ± 10 years were studied. IIEF5 scores of <22 were present in 406 participants (77.9%). Mild ED, mild-to-moderate ED, moderate ED, and severe ED were present in 34.6%, 26.6%, 10.4%, and 5.7%, respectively. Systolic and diastolic blood pressure were significantly lower in those with ED. Marital status, alcohol, cigarette, physical inactivity, obesity, hypertension, diabetes mellitus, and antihypertensive drug use were not associated with ED. ED was associated with poor QoL in the domains of social activities (odds ratio [OR] = 4.35; 95% confidence interval [CI]: 1.01-18.7), and overall health (OR = 2.27; 95% CI: 1.07-4.82). However, there was no association of ED with poor QoL in the domains of physical fitness (OR = 1.46; 95% CI: 0.82-2.59), feelings (OR = 1.43; 95% CI: 0.75-2.72), daily activities (OR = 4.72; 95% CI: 0.61-36.4), and change in health (OR = 1.75; 95% CI: 0.58-5.26). CONCLUSION: ED negatively impacts QoL in men.

Chronic kidney disease screening: Results of the 2013 World Kidney Day activities conducted at the Jos University Teaching Hospital

Background: Chronic kidney disease (CKD) is on the rise globally due to the increase in prevalence of common risk factors. Screening for CKD risk factors is important for early detection and institution of measures to retard its progression. This study aimed to determine the markers of CKD and its risk factors in a selected population.Methods: A cross sectional study of 510 individuals who were recruited during the 2013 world kidney day activities. History, clinical examination as well as the collection of urine and blood samples was performed on each participant to determine the presence of CKD and its risk factors. CKD markers were defined as the presence of proteinuria and or an estimated glomerular filtration rate (eGFR) of < 60ml/min.Results: The mean age of the participants was 39±11 years with majority of them being females (64.7%). Hypertension was present in 256 (50.2%) while diabetes mellitus was seen in 27 (5.29%). Forty three individuals (8.4%) had proteinuria while the prevalence of CKD markers was 10.5%. Only age, (OR =1.03; 95% CI: 1.01-1.06) was found to be a factor independently associated with the development of CKD. Conclusion: Though the prevalence of the traditional risk factors for CKD was high, only age was found to be independently associated with CKD markers.Screening exercise is encouraged for the early detection of CKD markers with a view to mitigating their impact

Hypertonicity: Pathophysiologic Concept and Experimental Studies.

Disturbances in tonicity (effective osmolarity) are the major clinical disorders affecting cell volume. Cell shrinking secondary to hypertonicity causes severe clinical manifestations and even death. Quantitative management of hypertonic disorders is based on formulas computing the volume of hypotonic fluids required to correct a given level of hypertonicity. These formulas have limitations. The major limitation of the predictive formulas is that they represent closed system calculations and have been tested in anuric animals. Consequently, the formulas do not account for ongoing fluid losses during development or treatment of the hypertonic disorders. In addition, early comparisons of serum osmolality changes predicted by these formulas and observed in animals infused with hypertonic solutions clearly demonstrated that hypertonicity creates new intracellular solutes causing rises in serum osmolality higher than those predicted by the formulas. The mechanisms and types of intracellular solutes generated by hypertonicity and the effects of the solutes have been studied extensively in recent times. The solutes accumulated intracellularly in hypertonic states have potentially major adverse effects on the outcomes of treatment of these states. When hypertonicity was produced by the infusion of hypertonic sodium chloride solutions, the predicted and observed changes in serum sodium concentration were equal. This finding justifies the use of the predictive formulas in the management of hypernatremic states.

Provision of Healthcare Services to Men Who Have Sex with Men in Nigeria: Students' Attitudes Following the Passage of the Same-Sex Marriage Prohibition Law.

PURPOSE: After signing of the Same-Sex Marriage (Prohibition) Act 2013 in Nigeria, media reports portray widespread societal intolerance toward the lesbian, gay, and bisexual population. This study was conducted to assess the attitudes of university undergraduates in Lagos state, Nigeria, toward provision of healthcare services for men who have sex with men (MSM), because the 2014 same-sex marriage prohibition law stipulates a jail sentence for organizations providing services to MSM. METHODS: A cross-sectional descriptive study was conducted by using self-administered questionnaires to collect information, including homophobic attitudes and views on access to healthcare, from 4000 undergraduates in 10 randomly selected faculties in two universities. During analysis, inter-university and inter-faculty comparison was carried out between medical and nonmedical students. RESULTS: Outright denial of healthcare services to MSM was supported by 37.6% of the 3537 undergraduates who responded, whereas denial of HIV prevention services was supported by 32.5%. However, compared with 38.7% and 34.1% of undergraduates from other faculties, 23.7% and 18.2% of medical students agreed that healthcare providers should not provide services to MSM and that MSM should not have access to HIV prevention services, respectively (P = 0.000). Although a significant proportion of the medical students supported the statement that doctors and other healthcare workers should be compelled to give priority to other groups before MSM (29.4% of medical vs. 47.2% of students from other faculties), a statistically significant difference was observed between the two groups of students. The homophobic statement with the highest support was that doctors and healthcare workers should be compelled to report MSM who come to access treatment (48.1% of medical vs. 57.4% of students from other faculties). CONCLUSION: A very high proportion of the undergraduate students had a negative attitude toward provision of healthcare services to MSM in Nigeria; the medical students were, however, less homophobic than their nonmedical counterparts. If attitudes translate to a lack of healthcare service provision to MSM, with the high burden of HIV among MSM in Nigeria, it is unlikely that the country will achieve the UNAIDS 90-90-90 target of 90% of the population knowing their HIV status, 90% of people living with HIV receiving sustained antiretroviral medication, and 90% of those receiving antiretroviral medication having viral suppression by 2020.

Chorioamnionitis in pregnancy: a comparative study of HIV-positive and HIV-negative parturients.

Chorioamnionitis is an important risk factor for vertical transmission of HIV/AIDS. We compared the prevalence and correlates of histologic chorioamnionitis (HCA) in HIV-positive and HIV-negative pregnant women. HIV-positive and -negative parturients were interviewed, examined and had their placentas examined histologically for chorioamnionitis. Data regarding HIV were also retrieved from their hospital records. A total of 298 parturients (150 HIV positive and 148 HIV negative) were enrolled. The two groups were similar in socio-demographic and obstetric parameters except for age. The prevalence of HCA was 57.1% in HIV-positive women and 61.6% in HIV-negative women (p = 0.43). HCA staging was associated with the number of intrapartum vaginal examinations in HIV-positive subjects and nulliparity in HIV-negative subjects. The number of intrapartum vaginal examinations and coitus in the week prior to delivery significantly affected the grade of HCA in HIV-negative subjects. The prevalence of HCA in both HIV-positive and HIV-negative is high. Most variables did not affect the occurrence of HCA in both groups studied except number of intrapartum examinations, coitus in the preceding one week and nulliparity, which were related to severity of the disease.

Respiratory failure in diabetic ketoacidosis.

Respiratory failure complicating the course of diabetic ketoacidosis (DKA) is a source of increased morbidity and mortality. Detection of respiratory failure in DKA requires focused clinical monitoring, careful interpretation of arterial blood gases, and investigation for conditions that can affect adversely the respiration. Conditions that compromise respiratory function caused by DKA can be detected at presentation but are usually more prevalent during treatment. These conditions include deficits of potassium, magnesium and phosphate and hydrostatic or non-hydrostatic pulmonary edema. Conditions not caused by DKA that can worsen respiratory function under the added stress of DKA include infections of the respiratory system, pre-existing respiratory or neuromuscular disease and miscellaneous other conditions. Prompt recognition and management of the conditions that can lead to respiratory failure in DKA may prevent respiratory failure and improve mortality from DKA.

Hyponatremia: pathophysiology, classification, manifestations and management.

Hyponatremia has complex pathophysiology, is frequent and has potentially severe clinical manifestations, and its treatment is associated with high risks. Hyponatremia can be hypertonic, isotonic or hypotonic. Hypotonic hyponatremia has multiple etiologies, but only two general mechanisms of development, defective water excretion, usually because of elevated serum vasopressin levels, or excessive fluid intake. The acute treatment of symptomatic hypotonic hyponatremia requires understanding of its targets and risks and requires continuous monitoring of the patient's clinical status and relevant serum biochemical values. The principles of fluid restriction, which is the mainstay of management of all types of hypotonic hyponatremia, should be clearly understood and followed. Treatment methods specific to various categories of hyponatremia are available. The indications and risks of these treatments should also be well understood. Rapid correction of chronic hypotonic hyponatremia may lead to osmotic demyelination syndrome, which has severe clinical manifestations, and may lead to permanent neurological disability or death. Prevention of this syndrome should be a prime concern of the treatment of hypotonic hyponatremia.