Overhydration, underhydration, and total body sodium: A tricky "ménage a trois" in dialysis patients.

Overhydration is a frequent complication in dialysis patients. It has been linked with hypertension, left ventricular hypertrophy, arterial stiffness, atherosclerosis uremic cardiomyopathy, and all-cause mortality or cardiovascular morbidity. In addition, predialysis underhydration is also associated with increased risk of death in ESRD patients. In this context, the optimal evaluation of hydration status is a must. However, this mission is not easy or accurate. In the last 10 years, several new methods have been tested in dialysis patients, particularly bioimpedance and lung ultrasonography. The precise clinical value of these techniques in the daily care of hemodialysis patients is not obvious yet. Sodium is also an important piece of this puzzle. Salt intake and/or removal of sodium during dialysis are essential determinants of optimal hydration status. Recent studies have revealed that salt and water homeostasis is also dependent of tissue sodium storage-increased in hemodialysis patients. However, the significance of increased sodium tissue storage as a cardiovascular risk factor and the relationship between tissue sodium content and hard CV endpoint have not yet been elucidated yet.

"Bowel prep hyponatremia" - a state of acute water intoxication facilitated by low dietary solute intake: case report and literature review.

BACKGROUND: Symptomatic hyponatremia is considered a rare complication of oral bowel preparation for colonoscopy. The pathophysiology underlying this phenomenon has been widely regarded as a mere sequela of excessive arginine vasopressin (AVP) release. CASE PRESENTATION: This case describes a 61-year old woman who developed acute hyponatremic encephalopathy when preparing for elective outpatient lower endoscopy. She had had negligible oral solute intake for two days and ingested four liters of clear fluid within two hours. On admission, the patient was agitated and had slurred speech. Treatment with hypertonic saline lead to full recovery. A brisk aquaresis confirmed acute dilutional hyponatremia. CONCLUSION: Apart from elevated AVP-levels, the amount and speed of fluid intake and concomitant low-solute intake constitute important risk factors in the development of clinically relevant hyponatremias in patients undergoing colonoscopies. Understanding that the cause of sodium imbalance in this scenario is multifactorial and complex is pivotal to recognizing and ideally preventing this complication, for which we propose the term "bowel prep hyponatremia".

Methylphenidate Overdose Causing Secondary Polydipsia and Severe Hyponatremia in an 8-Year-Old Boy.

OBJECTIVE: Attention deficit hyperactivity disorder (ADHD) is an increasingly common diagnosis of childhood that manifests with symptoms that affect cognitive, academic, behavioral, emotional, and social functioning. There are a multitude of pharmaceutical therapies to choose from when managing this condition, and though many studies on the safety and efficacy of these medications have been published, adverse effects still occur. CASE: This case discusses a previously healthy 8-year-old boy who had been prescribed 20-mg lisdexamfetamine dimesylate for ADHD however mistakenly took his brother's 36-mg methylphenidate extended-release tablets, resulting in hyperhidrosis, excessive thirst, polydipsia, and combative behavior that began within 3 hours of ingestion. He was evaluated at a community hospital emergency department and given lorazepam due to agitation and combativeness before discharge. However, he returned with hypothermia, hyponatremia, and status epilepticus resulting in intubation. Patient was transferred to our facility where a computer tomography of his head was negative and hyponatremia was corrected with 3% NaCl saline solution. A lumbar puncture was performed due to temperature instability before starting broad-spectrum antibiotics. Cerebrospinal fluid findings were normal, and he was extubated at 18 hours postingestion. Patient was discharged home after 3 days with no residual symptoms. DISCUSSION/CONCLUSIONS: Though both lisdexamfetamine dimesylate and methylphenidate are widely used among pediatricians today for treatment of ADHD, reports of life-threatening water intoxication as a result of overdose is rare. Studies have reported that severe 3,4-methylenedioxymethamphtamine toxicity in adults is associated with syndrome of inappropriate diuretic hormone (SIADH) secretion, hyponatremia, and seizures, along with serotonin-induced transient elevation in antidiuretic hormone. Adult schizophrenics who receive psychostimulants have also been shown to develop polydipsia with hyponatremia. Although the use of psychostimulants in adult schizophrenic patients has been studied, literature on toxicity and effects in the pediatric psychiatric population is scarce. We would suggest that this patient's polydipsia and hyponatremia are most likely a result of his ingestion of a toxic dose of a long-acting agent known to cause secondary psychosis.

Dialysate Sodium: Choosing the Optimal Hemodialysis Bath.

Fluid overload in patients undergoing hemodialysis contributes to cardiovascular morbidity and is a major cause of hospitalizations. It is often addressed by reinforcing the importance of a low-salt diet with patients and challenging estimated dry weights. More recently, interest has shifted toward the dialysate sodium prescription as a strategy to improve fluid overload and its adverse sequelae. The availability of high-flux high-efficiency dialysis in conjunction with the need to ensure its tolerability for patients has resulted in an increase in dialysate sodium prescriptions from 120 to ≥140 mEq/L. However, we are now tackling the unforeseen consequences associated with high dialysate sodium prescriptions. High dialysate sodium concentration is associated with high interdialytic weight gain, a commonly used surrogate for hypervolemia contributing to hypertension. The association between mortality and high dialysate sodium concentration remains controversial with conflicting data. It is clear that fluid management in the diverse end-stage renal disease population is extremely complex and more clinical trials are needed. In the meantime, while patients require treatments and clinical decisions need to be made, this review article attempts to summarize the current evidence for individualized dialysate sodium prescriptions based on patients' volume status, comorbid conditions, plasma sodium level, and hemodynamic response to dialysis therapy.

Acute symptomatic hyponatremia in a flight attendant.

Acute symptomatic hyponatremia after thiazide diuretic initiation is a medical emergency. Here we describe the case of a flight attendant who developed acute hyponatremia during a flight and the potential risk factors for developing this condition. A 57-year-old flight attendant with history of essential hypertension was recently started on a thiazide diuretic. As she did routinely when working, she increased her water intake during a flight from London to Mexico City. She complained of nausea and headache during the flight. Upon arrival, she developed severe disorientation and presented to the hospital emergency room (ER) with a Glasgow scale of 12, hypoxia, and a generalized tonic clonic seizure. Her laboratory results on arrival were consistent with severe hyponatremia (serum Na 116 mEql/L) and severe cerebral edema by CT scan. She was treated with hypertonic saline, with complete resolution of the neurologic symptoms. We describe high water intake and hypoxia related to decreased partial pressure of oxygen in the cabin as the two main risk factors for thiazide-induced acute hyponatremia in this case.

Recurrent rhabdomyolysis in a teenager with psychosis-intermittent hyponatremia-polydipsia syndrome.

OBJECTIVE: To report a case of recurrent hyponatremia and rhabdomyolysis in a teenager with psychogenic polydipsia. CASE SUMMARY: A 16-year-old boy was admitted with recurrent episodes of hyponatremia and rhabdomyolysis secondary to psychogenic polydipsia. He was treated with hypertonic saline, intravenous fluids, and supportive care. DISCUSSION: Psychogenic polydipsia is a condition characterized by compulsive drinking. Severe hyponatremia is a rare, but serious complication in patients with psychogenic polydipsia. Failure in cell volume regulatory mechanisms, defective osmoregulation, defective urinary dilution, and enhanced secretion of vasopressin are believed to play a role in the development of hyponatremia. Rhabdomyolysis can complicate severe hyponatremia, although the exact mechanism is not known. Antipsychotic drugs are also implicated in rhabdomyolysis. CONCLUSIONS: Severe hyponatremia and rhabdomyolysis can complicate psychogenic polydipsia. Patients receiving antipsychotic drugs with concomitant severe hyponatremia need to be monitored for rhabdomyolysis.

Strategies for removing fluids during hemodialysis.

Dry weight has most frequently been defined by the patient becoming symptomatic when fluid removal is attempted Hypervolemia and fluid removal require ongoing evaluation and the use of a number of strategies. This article reviews strategies for removing fluid during hemodialysis, hemodynamics of fluid removal, and interventions associated with the strategies for fluid removal.

Why should we use a low sodium dialysis solution for peritoneal dialysis?

Overhydration is highly prevalent in patients on peritoneal dialysis (PD), with inappropriately high sodium load supposedly playing a central role in the pathophysiology of the conditions. Recent studies have revealed the novel role of the interstitium as a buffer system for sodium ions, and it has been reported that patients on dialysis, including PD, present increased levels of sodium in the interstitium, such as in subcutaneous tissue and muscle. Hence, therapy for correction of overhydration should target the excess extracellular volume and the excess sodium storage in the interstitium. The ultrafiltrate obtained using the currently available PD solutions is hypo- to isonatric as compared to serum, which is disadvantageous for prompt and efficient sodium removal from the body in patients with overhydration. In contrast, use of low sodium PD solutions is characterised by iso- to hypernatric ultrafiltrate, which may beneficial for reducing sodium storage in the interstitium. Trials of low sodium PD solutions have reported possible clinical merits, for example, decreased blood pressure, reduced dryness of mouth and decreased body water content as assessed using bioimpedance methods. Given these observations and the high prevalence of overhydration in current PD populations, it makes medical sense that low sodium solutions be positioned as the new standard solution in the future. However, for medical safety, that is, to avoid hyponatremia and excessive decreases in blood pressure, further studies are needed to establish the appropriate compositions and applications of low sodium solutions.

"Underwater" EMR of sporadic laterally spreading nonampullary duodenal adenomas (with video).

BACKGROUND: EMR for the treatment of duodenal adenomas is challenging due to a thin wall and rich vascularity. OBJECTIVE: To evaluate a novel technique of "underwater" EMR without prior submucosal injection for the removal of large (≥2 cm) laterally spreading nonampullary duodenal adenomas. DESIGN: Prospective, observational study. SETTING: Tertiary academic referral center. PATIENTS: Twelve patients (median age, 60 years) meeting the inclusion criteria. INTERVENTIONS: Piecemeal EMR technique after sterile water submersion when using a double-channel endoscope. MAIN OUTCOME MEASUREMENTS: Technical success, adverse events, completeness of resection on follow-up endoscopy. RESULTS: Median adenoma size was 35 mm (25% greater than one-half circumference, 50% equal to one-third to one-half circumference, and 25% less than one-third circumference). Median procedure time was 65 minutes (range, 32-151). Final histology was tubular adenoma (7), tubulovillous adenoma (1), villous adenoma (3), and high-grade dysplasia (1). Eleven patients (92%) met the primary endpoint (technical success) and all patients met the secondary endpoint (completeness of resection). Median interval until follow-up endoscopy was 16 weeks (range, 11-56). Adverse events were as follows: delayed bleeding (3 patients, of whom 2 required transfusions), water intoxication syndrome manifested by altered mental status and hyponatremia (1), and stricture formation (1) that responded to balloon dilation. No perforation or postresection abdominal pain was found. LIMITATIONS: Single operator, single center, small sample size, limited follow-up. CONCLUSION: Underwater EMR for large sessile duodenal adenomas has high success rates for complete removal. The risk of delayed bleeding is significant, and precautions are needed when infusing a large volume of fluid into the GI tract.

A pinch of salt.

Pregnant women in labour are generally encouraged by their carers to continue taking plenty of oral fluids. This is sometimes supplemented by intravenous fluids either due to a clinical necessity or in preparation for a caesarean section. It is important that there is clear documentation of the amount of fluids received by pregnant women in the perinatal period as excessive maternal fluid has been associated with low serum sodium in neonates. This often goes under-recognised; therefore it is important to consider this in a neonate presenting with hyponatraemia in the first day of life. Presented here is a case of neonatal hyponatraemia secondary to excessive fluid taken in the perinatal period.

Fluid overload at initiation of renal replacement therapy is associated with lack of renal recovery in patients with acute kidney injury.

BACKGROUND: Patients with acute kidney injury (AKI) requiring initiation of renal replacement therapy (RRT) have poor short- and long-term outcomes, including the development of dialysis dependence. Currently, little is known about what factors may predict renal recovery in this population. METHODS: We conducted a single-center, retrospective analysis of 170 hospitalized adult patients with AKI attributed to acute tubular necrosis who required inpatient initiation of RRT. Data collection included patient characteristics, laboratory data, details of hospital course and degree of fluid overload at RRT initiation. The primary outcome was recovery of renal function to dialysis independence. RESULTS: Within 1 year of RRT initiation, 35.9% (61/170) of patients reached the primary end point of renal recovery. The median (interquartile range) duration of RRT was 11 (3-33) days and 83.6% (51/61) recovered prior to hospital discharge. Recovering patients had significantly less fluid overload at the time of RRT initiation compared to non-recovering patients (3.5 versus 9.3%, P = 0.004). In multivariate Cox proportional hazard regression analysis, a rise in percent fluid overload at dialysis initiation remained a significant negative predictor of renal recovery (hazard ratio 0.97, 95% confidence interval 0.95-1.00, P = 0.024). CONCLUSIONS: In patients with AKI, a higher degree of fluid overload at RRT initiation predicts worse renal recovery at 1 year. Clinical trials are needed to determine whether interventions targeting fluid overload may improve patient and renal outcomes.

Dead sea water intoxication.

Near drowning in the Dead Sea is associated with both respiratory manifestations and severe electrolyte abnormalities. It is often difficult to distinguish between the contributions of sea water aspiration or ingestion to clinical manifestations. We present a unique case of accidental ingestion of a large amount of Dead Sea water through a gastrostomy tube in which a patient with familial dysautonomia presented with severe electrolyte disturbances. Forced diuresis with large amounts of intravenous fluids resulted in clinical and biochemical improvement. Full recovery was achieved after 2 days of treatment.

Iatrogenic water intoxication during pelvic ultrasonography in a patient with diabetes insipidus.

Pelvic ultrasonography (US) is a simple and non-invasive radiologic test to evaluate the pelvic organs. It requires a full bladder for better visualization. Our case is a 14-year-old female with diabetes insipidus (DI) who admitted to the pediatric emergency service with the complaints of seizure and agitation after drinking 4 liters of water in one hour for a pelvic US examination due to work-up for delayed puberty. Her biochemical and clinical evaluation revealed water intoxication (WI). To our knowledge, this is the first WI case developed in a patient with DI. Here, we discuss the underlying factors leading to this complication and recommended an approach to obtain a better sonographic image without necessitating oral water intake to fill the urinary bladder.

Psychogenic polydipsia: comparison of a community sample with an institutionalized population.

The prevalence of psychogenic polydipsia, which can cause hyponatremia, is unknown in the outpatient psychiatric community. We report on 42 individuals who were admitted for hyponatremia due to psychogenic polydipsia. No significant differences were found between the community and institutional samples regarding demographics, psychiatric diagnosis, or severity of hyponatremia.

The impact of anesthesia on glycine absorption in operative hysteroscopy: a randomized controlled trial.

BACKGROUND: Operative hysteroscopy requires the use of a distension medium and its absorption can lead to serious consequences from intravascular volume overload and water intoxication. We compared the impact of 2 types of anesthesia (general anesthesia and local anesthesia with sedation) on the absorption of glycine solution in operative hysteroscopy. METHODS: A randomized controlled trial was conducted over a 17-month period. Eligible patients undergoing operative hysteroscopy for abnormal uterine bleeding were randomized in 2 groups: a general anesthesia group and a local anesthesia with sedation group. The primary outcome was the median absorption of the glycine solution (10th-90th percentile) measured with an automated tandem canister system. Secondary outcomes included incidence of absorption >1000 mL, discontinued surgery because of excessive absorption, median change in serum sodium, postoperative hyponatremia, and patients' postoperative quality of life at 24 hours (8-item Short Form Health Survey questionnaire). Nonparametric analyses (Mann-Whitney U test, χ(2) test, and Fisher exact test) were used. RESULTS: Of 142 eligible patients, 95 agreed to participate and were randomized. Women who underwent general anesthesia had a higher median absorption of the glycine solution (10th-90th percentile) compared with women who underwent local anesthesia with sedation (480 mL [76-1300 mL] vs 253 mL [70-728 mL]; P = 0.005). General anesthesia was also associated with a higher rate of glycine solution absorption (>1000 mL [20% vs 4%; P = 0.009]) and a more rapid rate of decrease in serum sodium (≥10 mEq/L [8% vs 0%; P = 0.005]) than local anesthesia with sedation. Postoperative quality of life measures as rated by the patients were comparable between the 2 groups. CONCLUSION: Compared with general anesthesia, local anesthesia with sedation is associated with less glycine absorption and should be considered the preferred method of anesthesia for operative hysteroscopy.

Successful treatment of cardiac arrest following hysteroscopic surgery using extracorporeal membrane oxygenation: A case report.

RATIONALE: Cardiac arrest caused by water intoxication syndrome following hysteroscopic surgery is a rare but life-threatening occurrence. Extracorporeal membrane oxygenation (ECMO) is rarely used to treat water intoxication syndrome in hysteroscopic surgery. Here, we successfully treated a patient with water intoxication syndrome following hysteroscopic surgery with ECMO. PATIENT CONCERNS: We report a rare case of cardiac arrest during hysteroscopic surgery treated with veno-venous (VV) ECMO. DIAGNOSIS: Water poisoning syndrome was diagnosed by electrolyte examination, the lowest value of serum sodium was 110.7 mmol/L. INTERVENTIONS: VV-ECMO was prescribed as a measure after traditional cardiopulmonary resuscitation. RESULTS: ECMO was successfully evacuated on day 5 and the patient was discharged on day 45. CONCLUSION: Mastering the hysteroscopic operative techniques and using a bipolar hysteroscopic generator, isotonic fluid, perfusion pressures less than 100 mm Hg, and local anesthesia may reduce the risk of hysteroscopic water intoxication syndrome. During hysteroscopic surgery, patients may experience cardiac arrest and fatal water intoxication syndrome. Even when traditional cardiopulmonary resuscitation is successful, VV ECMO may contribute to the recovery of brain function if oxygenation is not maintained.

Two unusual pediatric cases of dilutional hyponatremia.

Dilutional hyponatremia, although not uncommon, is an underestimated problem in the pediatric population. In most cases, it results from excessive hydration or water retention, also described as the so-called water intoxication. One of the most known causes is the use of desmopressin in enuretic children. This drug enhances the free water reabsorption in the renal collecting ducts. The addition of the anticholinergic agent oxybutynin aggravated the condition by causing a dry mouth with excessive thirst and water intake in our first case. Dietary water overconsumption, either voluntary or involuntary, is a phenomenon seen in formula-fed babies. But in our second case, a game involving forced ingestion of large amounts of water had serious consequences including hyponatremia-related coma. An effort should therefore be made to inform caretakers about the risks of these games. These cases, provoked by rather unusual and peculiar causes, illustrate again that electrolytes and especially serum [Na(+)] are key points to be determined in a child with diminished consciousness. Moreover, an accurate history including the intake of medication and dietary information should be made.

[Oxytocin and syndrome of inappropriate secretion of antidiuretic neonatal hormone. Case report of early severe hyponatremia and literature review]. / Oxitocina y sindrome de secreción inapropiada de hormona antidiurética neonatal. Reporte de un caso de hiponatremia severa temprana y revisión de la bibliografia.

This is a clinical case presentation of a full term newborn infant who suffered severe hyponatremia and early seizures, associated with maternal fluid overload with electrolyte free solutions and high doses of oxytocin for labor augmentation. Although this condition has been recognized since the 1960's with isolated reports, this particular case has features that needs further investigation, not only for the unsually severe hyponatremia, but most importantly we think, for the prominent signs of fluid retention, the infant had, that suggest excessive antidiuretic activity probably due to oxytocin. These findings are consistent with syndrome of inappropriate secretion of antidiuretic hormone. Although until now there is no proof that oxytocin by itself produces this syndrome. We think the association is possible in certain clinical circumstances, such as those found in this case. We also, briefly discussed the pathophysiology of perinatal hyponatremia, the neonatal treatment of this condition and the current guidelines for the women in labor. Hyponatremia should not be considered a benign condition, since in the neonate, it may affect brain function.