Hypotonic Group Research Articles

Hypotonic fluid reduce serum sodium compared to isotonic fluids during anesthesia induction in pediatric patients undergoing maxillofacial surgery-type of infusion affects blood electrolytes and glucose: an observational study.

BackgroundReportedly, administration of hypotonic fluids containing 30.8–74 mEq/L sodium with 5 % glucose may lead to serious hyponatremia or hyperglycemia. In Japan, hypotonic fluids containing 90 mEq/L sodium with 2.6 % glucose are commonly used. We compared blood electrolyte balance and blood glucose concentration with the use of isotonic (140 mEq/L sodium with 1 % glucose) versus hypotonic fluids in pediatric patients.MethodsWe studied 77 children aged 5 months to 2 years who underwent oro-maxillofacial surgery and dental treatment under general anesthesia. Patients were categorized according to the fluids infused (hypotonic or isotonic). Blood samples were obtained from the dorsalis pedis artery between the conclusion of anesthesia induction and commencement of surgery. We compared blood sodium, potassium and glucose concentrations in the two fluid groups during the pre-anesthesia and post-anesthesia-induction periods.ResultsThere were no significant differences in pre-anesthesia values between isotonic (n = 35) and hypotonic groups (n = 42). There were significant differences between isotonic and hypotonic groups in post-anesthesia-induction concentrations of sodium (isotonic, 138.7 ± 1.4 mEq/L; hypotonic, 137.5 ± 1.3 mEq/L; p = 0.0003) and glucose (isotonic, 88.0 ± 9.4 mg/dL; hypotonic, 109.9 ± 18.4 mg/dL; p < 0.0001), while potassium concentrations were not significantly different (isotonic, 4.0 ± 0.3 mEq/L; hypotonic, 4.0 ± 0.2 mEq/L; p = 0.6615) between the two groups.ConclusionIsotonic solution administration enables avoidance of serum sodium reduction and serum glucose elevation in infants, and may therefore enhance patient safety in comparison with hypotonic solutions.Trial registrationUniversity Hospital Medical Information Network Clinical Trials Registry (UMIN000014648), registration 25 July 2014.

A prospective trial comparing isotonic with hypotonic maintenance fluids for prevention of hospital-acquired hyponatraemia

Background:Recent literature suggests that hypotonic fluids increase the risk of hospital-acquired hyponatraemia; despite this, hypotonic fluids are widely used.Objectives:To compare the change in serum sodium following the use of hypotonic (0.3% saline, 0.45% saline) or isotonic (0.9% saline) intravenous (IV) maintenance solutions in hospitalised children.Study design:This was a randomised controlled trial. Children aged 3 months to 15 years with medical or surgical disorders were randomised to receive one of three maintenance IV fluids: two hypotonic solutions (3.3% dextrose in 0.3% saline or 5% dextrose in 0.45% saline) and one isotonic solution (5% dextrose in 0.9% saline). The primary outcome was serum sodium levels at 8 hours. Secondary outcomes included the incidence of hospital-acquired hyponatraemia, adverse events attributable to IV solutions and length of hospital stay.Results:151 children were assigned randomly to receive 0.3% saline (n = 49), 0.45% saline (n = 50) or 0.9% saline (n = 52). Baseline characteristics were similar for the three groups. At 8 hours, mean (SD) serum sodium was lower in the hypotonic solutions groups [0.3% saline 134.65 (1.9) mmol/L, 0.45% saline 134.90 (2.3) mmol/L than 0.9% saline 137.98 (2.8) mmol/L] (P < 0.0001). The incidence of hospital-acquired hyponatraemia was higher in the hypotonic groups [0.3% saline 10/49 (20.4%), 0.45% saline 11/50 (22%) than 0.9% saline 1/52 (1.9%), P = 0.006). There were no differences in other adverse effects or length of hospital stay between the groups.Conclusion:Hypotonic IV solutions increase the incidence of hospital-acquired hyponatraemia. Isotonic solutions are a safer alternative.

Intraoperative corneal thickness change and clinical outcomes after corneal collagen crosslinking: Standard crosslinking versus hypotonic riboflavin

To determine intraoperative changes in corneal thickness and outcomes of corneal collagen crosslinking (CXL) using 2 intraoperative regimens: riboflavin-dextran or hypotonic riboflavin. Cornea and refractive surgery practice, Teaneck, New Jersey, USA. Prospective randomized case series. Eyes with keratoconus or corneal ectasia were treated. All eyes received preloading with riboflavin 0.1% in 20% dextran. During ultraviolet-A (UVA) exposure, patients were randomly assigned to 1 of 2 study arms; that is, riboflavin-dextran or hypotonic riboflavin. Intraoperative pachymetry was measured before and after the corneal epithelium was removed, after initial riboflavin loading, and after UVA light exposure. Patients were evaluated for maximum keratometry (K), uncorrected distance visual acuity (UDVA), corrected distance visual acuity, corneal thickness, and endothelial cell count (ECC). Forty-eight eyes were treated. After removal of the epithelium and riboflavin loading, the mean pachymetry was 430μm and 432μm in the standard group and hypotonic group, respectively. Immediately after 30-minute UVA administration, the mean pachymetry was 302μm and 342μm, respectively. There was no statistically significant difference in the postoperative maximum K change, UDVA, corneal thickness, or ECC between the 2 groups. The cornea thinned substantially during the CXL procedure. The use of hypotonic riboflavin rather than riboflavin-dextran during UVA administration decreased the amount of corneal thinning during the procedure by 30%, from 128μm to 90μm. However, there were no significant differences in clinical efficacy or changes in ECC or function between groups postoperatively. In general, corneal thinning during CXL did not seem to compromise the safety of the endothelium. Dr. Hersh is a consultant to Avedro, Inc. Dr. Rosenblat has no financial or proprietary interest in any material or method mentioned.

A prospective trial comparing isotonic with hypotonic maintenance fluids for prevention of hospital-acquired hyponatraemia

Recent literature suggests that hypotonic fluids increase the risk of hospital-acquired hyponatraemia; despite this, hypotonic fluids are widely used.To compare the change in serum sodium following the use of hypotonic (0.3% saline, 0.45% saline) or isotonic (0.9% saline) intravenous (IV) maintenance solutions in hospitalised children.This was a randomised controlled trial. Children aged 3 months to 15 years with medical or surgical disorders were randomised to receive one of three maintenance IV fluids: two hypotonic solutions (3.3% dextrose in 0.3% saline or 5% dextrose in 0.45% saline) and one isotonic solution (5% dextrose in 0.9% saline). The primary outcome was serum sodium levels at 8 hours. Secondary outcomes included the incidence of hospital-acquired hyponatraemia, adverse events attributable to IV solutions and length of hospital stay.151 children were assigned randomly to receive 0.3% saline (n = 49), 0.45% saline (n = 50) or 0.9% saline (n = 52). Baseline characteristics were similar for the three groups. At 8 hours, mean (SD) serum sodium was lower in the hypotonic solutions groups [0.3% saline 134.65 (1.9) mmol/L, 0.45% saline 134.90 (2.3) mmol/L than 0.9% saline 137.98 (2.8) mmol/L] (P < 0.0001). The incidence of hospital-acquired hyponatraemia was higher in the hypotonic groups [0.3% saline 10/49 (20.4%), 0.45% saline 11/50 (22%) than 0.9% saline 1/52 (1.9%), P = 0.006). There were no differences in other adverse effects or length of hospital stay between the groups.Hypotonic IV solutions increase the incidence of hospital-acquired hyponatraemia. Isotonic solutions are a safer alternative.

Comparison of two maintenance electrolyte solutions in children in the postoperative appendectomy period: a randomized, controlled trial

ObjectiveTo compare two electrolyte maintenance solutions in the postoperative period in children undergoing appendectomy, in relation to the occurrence of hyponatremia and water retention. MethodsA randomized clinical study involving 50 pediatric patients undergoing appendectomy, who were randomized to receive 2,000mL/m2/day of isotonic (Na 150 mEq/L or 0.9% NaCl) or hypotonic (Na 30 mEq/L NaCl or 0.18%) solution. Electrolytes, glucose, urea, and creatinine were measured at baseline, 24h, and 48h after surgery. Volume infused, diuresis, weight, and water balance were analyzed. ResultsTwenty‐four patients had initial hyponatremia; in this group, 13 received hypotonic solution. Seventeen patients remained hyponatremic 48h after surgery, of whom ten had received hypotonic solution. In both groups, sodium levels increased at 24h (137.4±2.2 and 137.0±2.7mmol/L), with no significant difference between them (p=0.593). Sodium levels 48h after surgery were 136.6±2.7 and 136.2±2.3mmol/L in isotonic and hypotonic groups, respectively, with no significant difference. The infused volume and urine output did not differ between groups during the study. The water balance was higher in the period before surgery in patients who received hypotonic solution (p=0.021). ConclusionsIn the post‐appendectomy period, the use of hypotonic solution (30 mEq/L, 0.18%) did not increase the risk of hyponatremia when compared to isotonic saline. The use of isotonic solution (150 mEq/L, 0.9%) did not favor hypernatremia in these patients. Children who received hypotonic solution showed higher cumulative fluid balance in the preoperative period.

Isotonic versus Hypotonic Parenteral Maintenance Fluids in Very Severe Pneumonia.

To compare the risk of hyponatremia between hypotonic and isotonic parenteral maintenance solutions (PMS) administered to children with very severe pneumonia, admitted in the general pediatric ward. A randomized controlled open label trial was conducted in the pediatrics department of a tertiary care medical college hospital including euvolemic children 2 mo to 5 y of age, fulfilling the WHO clinical definition of very severe pneumonia and requiring PMS. They were randomized to receive either isotonic PMS (0.9% saline in 5% dextrose and potassium chloride 20 meq/L) or hypotonic PMS (0.18% saline in 5% dextrose and potassium chloride 20 meq/L) at standard rates for next 24 h. A total of 119 children were randomized (59: Isotonic; 60: Hypototonic PMS). Nine (15%) children in the isotonic PMS group and 29 (48%) in the hypotonic PMS group developed hyponatremia during the study period, (p <0.001) with a relative risk being 3.16 (95% CI 1.64 to 6.09). Mean serum sodium was significantly lower in the hypotonic group compared to the isotonic group (p < 0.001 each at 6, 12 and 24 h). The difference in mean change in serum sodium from baseline was also significant at 12 and 24 h (5.4 and 5.8 meq/L respectively; p < 0.001 each). This study demonstrates the rationality of the use of isotonic PMS in children with respiratory infections, a condition regularly encountered by most pediatricians.

Comparison of two maintenance electrolyte solutions in children in the postoperative appendectomy period: a randomized, controlled trial

ObjectiveTo compare two electrolyte maintenance solutions in the postoperative period in children undergoing appendectomy, in relation to the occurrence of hyponatremia and water retention. MethodsA randomized clinical study involving 50 pediatric patients undergoing appendectomy, who were randomized to receive 2,000mL/m2/day of isotonic (Na 150 mEq/L or 0.9% NaCl) or hypotonic (Na 30 mEq/L NaCl or 0.18%) solution. Electrolytes, glucose, urea, and creatinine were measured at baseline, 24h, and 48h after surgery. Volume infused, diuresis, weight, and water balance were analyzed. ResultsTwenty-four patients had initial hyponatremia; in this group, 13 received hypotonic solution. Seventeen patients remained hyponatremic 48h after surgery, of whom ten had received hypotonic solution. In both groups, sodium levels increased at 24h (137.4±2.2 and 137.0±2.7mmol/L), with no significant difference between them (p=0.593). Sodium levels 48h after surgery were 136.6±2.7 and 136.2±2.3mmol/L in isotonic and hypotonic groups, respectively, with no significant difference. The infused volume and urine output did not differ between groups during the study. The water balance was higher in the period before surgery in patients who received hypotonic solution (p=0.021). ConclusionsIn the post-appendectomy period, the use of hypotonic solution (30 mEq/L, 0.18%) did not increase the risk of hyponatremia when compared to isotonic saline. The use of isotonic solution (150 mEq/L, 0.9%) did not favor hypernatremia in these patients. Children who received hypotonic solution showed higher cumulative fluid balance in the preoperative period

Safety and efficacy of isotonic (0.9%) vs. hypotonic (0.18%) saline as maintenance intravenous fluids in children: a randomized controlled trial.

To compare the safety and efficacy of isotonic versus hypotonic maintenance fluid in children. Randomized controlled trial. Tertiary-level teaching hospital. 60 children (age 0.5 to 12 years) who were admitted and anticipated to receive intravenous fluid for the next 48 hours. Hypotonic fluid (Standard maintenance volume as 0.18% NaCl in 5% dextrose) or Isotonic fluid (60% Standard maintenance volume as 0.9% NaCl solution in 5% dextrose). Primary: Incidence of hyponatremia. Secondary: Serum sodium, serum osmolality, blood sugar, blood urea, serum creatinine, serum potassium, serum chloride, pH, urine output, change in weight, morbidity and death. At 24 hours, hyponatremia was noted in 7 (24%) patients in the isotonic and 16 (55%) in hypotonic group (P=0.031). At 48 hours, hyponatremia was noted in 4 (14%) and 13 (45%) patients in isotonic and hypotonic group, respectively (P=0.02). There was significant change in sodium levels in both isotonic (P=0.036) and hypotonic (P<0.001) intervention groups. The peak fall in mean serum sodium level was noted at 24 hours (-6.5, 95%CI: -3.5, -9.6 mEq/L; P<0.001) in hypotonic group. In isotonic group, there was significant increase between 24 and 48 hours (4.3, 95% CI: 0.1, 8.4 mEq/L; P=0.04). Reduced volume isotonic fluid results in fewer episodes of hyponatremia than hypotonic fluid in sick children during the first 48 hours of intravenous fluid therapy.

Rehydration: Comparison of Isotonic and Hypotonic Saline with Dextrose in Children

Introduction: Early rehydration with bolus fluid can be life saving. We compared isotonic saline with a hypotonic fluid which was composed of saline 0.9%, dextrose, and bicarbonate in our clinical setting. Materials and Methods : 71 children entered to this study , 41 cases received isotonic saline and the remaining 30 cases received hypotonic fluid which was composed of 750 cc saline 0.9%, 28 cc bicarbonate 7.5%, and 222cc dextrose 5% for resuscitation fluid challenge at a dose of 20ml/kg over 20 minutes that could be repeated up to 3 times as needed. Serum sodium (Na), potassium (K), blood sugar (BS) and bicarbonate (HCo3) were measured before initiating rehydration and after 3 hours. T independent test was used to compare the values between the two groups and T paired test in each group in SPSS 16. The level of significance was set at 0.05. Results: Serum Na, K, BS, and HCo3 were 134±5, 3.8 ±0.6, 90±16, and 11.6±3.6 before and 135±4, 3.7±0.5, 73±13, and 15±3 three hours after rehydration in the isotonic group, respectively. In the isotonic rehydrated group, BS drop and HCo3 rise significantly (p<0.001). Serum Na, K, BS, and HCo3 were 134±6, 3.6±0.6, 91±15, and 10.1±1.9 before and 136±3, 3.6±0.4, 94±10, and 15±2 three hours after rehydration in the hypotonic saline group, respectively. Serum sodium increased 2meq/dl (p<0.04) and bicarbonate increased 4.9 meq/l (P< 0.001). Conclusions: The hypotonic serum containing 115meq/l of sodium chloride combined with 25meq/l of sodium bicarbonate and dextrose 1.1% is not associated with a decrease in BS or hyponatremia. It also increases serum HCo3 prominently. Keywords : Hypotonic Solutions; Isotonic Solutions; Dehydration; Child.

Isotonic versus hypotonic fluid supplementation in term neonates with severe hyperbilirubinemia – a double‐blind, randomized, controlled trial

To compare the incidence of hyponatremia in full-term neonates with severe hyperbilirubinemia, receiving intravenous fluid supplementation with 0.2% saline in 5% dextrose versus 0.9% saline in 5% dextrose, to prevent blood exchange transfusion (BET). In this double-blind, randomized, controlled trial, full-term newborns (≥37 weeks), appropriate for gestational age, with severe non-haemolytic hyperbilirubinemia (serum bilirubin ≥ 20 mg/dL) were enrolled. Eligible neonates were randomized to receive either 0.2% saline in 5% dextrose (hypotonic fluid group) or 0.9% saline in 5% dextrose (isotonic fluid group) over 8 hrs, in addition to phototherapy. The primary outcome was proportion of neonates developing hyponatremia (serum Na < 135 mmol/L) after 8 h. Forty-two neonates were analysed in each group. Proportion of neonates developing hyponatremia after 8 h was higher in hypotonic fluid group as compared to isotonic fluid group (48.8% vs. 10.5%, p < 0.001). However, a larger proportion in isotonic fluid group developed hypernatremia (39.5% vs. 12.2%, p < 0.001). The rate of BET was similar in both groups. In full-term neonates with severe hyperbilirubinemia, administration of hypotonic fluid to prevent BET was associated with a higher incidence of hyponatremia while isotonic fluid was associated with an increased incidence of hypernatremia.

Hypotonic versus isotonic maintenance fluids in critically ill children: a multicenter prospective randomized study

Study the influence of hypotonic (HT) and isotonic (IT) maintenance fluids in the incidence of dysnatraemias in critically ill children. Prospective, randomized study conducted in three paediatric intensive care units (PICU). One hundred and twenty-five children requiring maintenance fluid therapy were included: 62 received HT fluids (50-70 mmol/L tonicity) and 63 IT fluids (156 mmol/L tonicity). Age, weight, cause of admission, sodium and fluid intake, and diuresis were collected. Blood electrolytes were measured on admission, 12 and 24 h later. Blood sodium levels at 12 h were 133.7±2.7 mmol/L in HT group vs. 136.8±3.5 mmol/L in IT group (p=0.001). Adjusted for age, weight and sodium level at PICU admission, the blood sodium values of patients receiving HT fluids decrease by 3.22 mmol/L (CI: 4.29/2.15)(p=0.000). Adjusted for age, weight and hyponatraemia incidence at admission, patients receiving HT fluids increased the risk of hyponatraemia by 5.8-fold (CI: 2.4-14.0) during the study period (p=0.000). Hypotonic maintenance fluids increase the incidence of hyponatraemia because they decrease blood sodium levels in normonatraemic patients. IT maintenance fluids do not increase the incidence of dysnatraemias and should be considered as the standard maintenance fluids.

Comparison of Polyethylene Glycol with and without Electrolytes in the Treatment of Constipation in Elderly Institutionalized Patients

Polyethylene glycol (PEG) is a commonly used osmotic laxative. PEG with electrolytes is mixed with water, but PEG without electrolytes can also be mixed with, for example, juice, coffee or tea, making it more palatable. Laxatives, including PEG, are commonly used by the elderly, particularly those living in institutions. Few clinical studies, however, have investigated the use of PEG in this population. To test whether PEG 4000 without electrolytes (hypotonic PEG) is at least as effective and safe as PEG 4000 with electrolytes (isotonic PEG) in elderly institutionalized constipated patients. The acceptability of the treatments was also compared. This randomized, double-blind, parallel-group study was conducted at ten private assisted-living facilities or communal nursing homes in Finland. Eligible patients were required to have used isotonic PEG at a stable dose without any other treatment for constipation (except for Plantago ovata seeds) for at least 2 weeks prior to a run-in period. After the 1-week run-in, 62 patients (mean age 86 years; range 66-99 years) were randomly either switched to receive hypotonic PEG or continued to receive isotonic PEG, both dissolved in water, 12 g once or twice daily or once every other day, for 4 weeks. Stool frequency, stool consistency, stool straining and gastrointestinal symptoms were recorded. Safety laboratory tests were conducted before and after the treatment period. Acceptability was assessed at the end of the study. At week 4, mean (SD) weekly stool frequencies in the hypotonic and isotonic PEG groups were 8.5 (4.5) and 8.4 (3.6), respectively. The mean stool frequency ratio (95% CI) was 0.90 (0.74, 1.10); thus, the PEG products were considered equally effective. At week 4, the proportion of patients with soft or normal stool consistency was higher in the hypotonic PEG group than in the isotonic PEG group (70% vs 52%), but this difference was not statistically significant. There were no differences between the groups in stool straining or gastrointestinal symptoms. In the safety laboratory tests, no clinically significant differences between the groups were detected, although plasma sodium level was statistically significantly lower in the hypotonic PEG group at the end of the study (137.7 vs 138.9 mmol/L, respectively; p = 0.012). Most patients were willing to continue their study treatment (85% in the hypotonic PEG and 63% in the isotonic PEG group; p = 0.070). Compared with only 12% of the patients receiving hypotonic PEG, however, 31% of the patients in the isotonic PEG group rated the taste of the study treatment as bad or very bad (p = 0.101). Hypotonic PEG solution is as effective as isotonic PEG in the treatment of constipation in elderly institutionalized patients. Both treatments appear safe, well tolerated and, when dissolved in water, well accepted by the majority of the patients. When desired, switching from isotonic to hypotonic PEG can safely take place in elderly individuals without compromising efficacy.

The effect of gradient osmotic pressure on the proliferation of inner medullary collecting duct cell in rats

Objective To investigate the change of the proliferation of inner medullary collecting duct (IMCD) cell under the sodium chloride gradient osmotic pressure circumstance.Methods Collagenase digostion and hypotonic dissolve were used to isolate and culture primary IMCD cell of Sprague-Dawley rat.Cells were divided into hypotonic medium(200 mosmol/kg),isotonic medium(300 mosmol/kg) and hpertonic medium(600 mosmol/kg) groups,after 90% confluence in the normal culture medium.The cellular cytotoxicity was analyzed by MTT assay(methyl thiazolyl tetrazolium) and flow cytometer was used to detect cell cycle and apoptosis ratio.Results IMCD cells were resistant to osmotic pressure change.Cell apoptosis ratio under hypertonic circumstance was significantly higher than hypotonic and isotonic groups after 12 hours treatment(1.1%±0.10% vs 0.565% ±0.096%,0.104%±0.08%,P＜0.05).Cell apoptosis ratio in hypertonic circumstance was slightly lower than hypotonic group (P＞0.05) but higher than isotonic group(P＞0.05) after 24 hours treatment.Conclusion The proliferation of IMCD cell was inhibited under hypertonic circumstance,especially after 12 hours treatment,and the inhibitory effect of hypotonic circumstance increased after 24 hours treatment. Key words: Inner medullary collecting duct cell; Osmotic pressure; Cell cycle; Apoptosis

The use of isotonic fluid as maintenance therapy prevents iatrogenic hyponatremia in pediatrics: A randomized, controlled open study*

Hypotonic fluids are widely used in pediatrics. Several articles have reported the risk of iatrogenic hyponatremia secondary to this practice. We primarily intend to determine whether the use of isotonic fluids prevents hyponatremia and, secondly, whether these fluids increase the incidence of adverse events. One hundred twenty-two pediatric patients hospitalized in intensive care unit requiring maintenance fluid therapy were randomized to receive isotonic fluids (isotonic group, NaCl = 140 mEq/L) or hypotonic fluids (hypotonic group, NaCl <100 mEq/L). Electrolyte blood concentration, glycaemia, and blood pressure were measured at 0, 6, and 24 hrs after the beginning of fluid therapy. Plasma creatinine, urine specific gravity, and urine electrolyte concentration were measured at 6 hrs. Standard intention-to-treat analysis and Bayesian analysis were conducted to assess the probability of hyponatremia and hypernatremia in each group. At the time of admission to hospital, no differences in natremia or the percentage of hyponatremia were found between groups. At 24 hrs, the percentage of hyponatremia in the hypotonic group was 20.6% as opposed to 5.1% in the isotonic group (p = 0.02). No differences in the number of adverse events other than hyponatremia were observed between groups. The use of hypotonic fluids increases the risk of hyponatremia when compared with isotonic fluids at 24 hrs following infusion (number needed to harm [confidence interval 95%] = 7[4;25]). In our sample, the use of isotonic fluids did not increase the incidence of adverse events compared with hypotonic fluids.

Incidence of Postoperative Hyponatremia and Complications in Critically-Ill Children Treated with Hypotonic and Normotonic Solutions

To determine the incidence and clinical consequences of postoperative hyponatremia in children. We performed a retrospective analysis of postoperative admissions to the pediatric intensive care unit (excluding cardiac, neurosurgical, and renal). The incidence of severe (serum sodium < 125 mmol/L or symptoms) and moderate (serum sodium < 130 mmol/L) hyponatremia in children receiving hypotonic (HT) and normotonic (NT) fluids was calculated. Out of a total of 145 children (568 sodium measurements; 116 HT and 29 NT), we identified 16 with hyponatremia (11%). The incidences of moderate (10.3% vs 3.4%, P = .258) and severe (2.6% vs 0%; P = .881) hyponatremia were not significantly different in the HT and NT groups. There were no neurologic sequelae or deaths related to hyponatremia. In our study group, hyponatremia was common, but morbidity and death were not observed. Careful monitoring of serum sodium level may be responsible for this lack of adverse outcomes. Larger, prospective studies are needed to determine whether the incidence of hyponatremia differs between the HT and NT groups.

Efectos renales y sistémicos en la prevención de la nefrotoxicidad por contraste con sueros salino (0,9%) e hiposalino (0,45%)

Physiological and hypotonic saline solutions have been used interchangeably for preventing contrast media nephrotoxicity. No analysis of the possible differential effects of the two solutions on the milieu interieur or intercompartmental fluid volumes has been performed. Our aim was to study the systemic and renal effects of two types of saline solution regularly used to prevent contrast media nephrotoxicity in patients undergoing coronary angiography. Changes in electrolyte levels and volume distribution were studied in 71 individuals who were randomized to receive either 0.9% isotonic saline (n=36) or 0.45% hypotonic saline (n=35) during the 12 hours before and after contrast injection (2000 mL in each period). The creatinine level was elevated equally often in the isotonic and hypotonic saline groups. Isotonic saline administration led to reductions in hemoglobin level, hematocrit and plasma albumin level, and to increases in plasma volume, by 12.3% and 10.4% at 24 and 48 hours, respectively. These changes were significant compared with baseline measurements and compared with the group that received hypotonic saline. Neither of the two saline solutions resulted in a change in plasma atrial natriuretic peptide level. Plasma and urine osmolality decreased only with hypotonic saline. The increase in plasma creatinine level was similar with both isotonic and hypotonic saline. During standard therapy for preventing contrast media nephrotoxicity, (1) isotonic saline, but not hypotonic saline, increased plasma volume; (2) this increase did not raise the atrial natriuretic peptide level; and (3) no difference in the increase in serum creatinine level was observed between the two saline solutions. These findings provide evidence that 0.45% saline, at a dose suitable for preventing contrast media nephrotoxicity, is associated with a lower risk of volume expansion. This result is important for patients with severely impaired ventricular function.

Effect of hypotonic medium on expression of aquaporin-4 in astrocytes

To investigate the expression of aquaporin-4 (AQP4) and its role in cultured rat astrocytes after exposure to hypotonic medium. Rat cerebral cortical astrocytes from 2 days newborn Wistar rats were undergone the pure culture. The cells were divided into control group and hypotonic groups randomly, in which group was examined at interval times of 3, 6, 12 and 24 h, respectively (n = 6), and its model of cell edema was established by exposed to hypotonic medium. The cells of the control group were cultured in normal culture medium. Inverted microscope and transmission electron microscope were used to observe the cells changes. The reactivity and rules of AQP4mRNA and protein expression of astrocyte to hypotonic medium were studied by RT-PCR, immunocytochemistry, the activity of LDH and imaging analysis. There was no significant change in the control group. After astrocytes cultured for 3, 6, 12, 24 h with hypotonic medium (268, 254, 240 mmol/L), the astrocytes showed typical features of cell edema, especially in lower osmolality group. The activity of LDH showed a significant change than those in the control group after astrocytes exposed to hypotonic medium (P < 0.05). RT-PCR and immunocytochemistry analysis confirmed that the expression of AQP4mRNA and protein was remarkably increased (P < 0.05), up-graduated expression of AQP4 was correlated with hypotonic medium and time dependent manner. The AQP4mRNA expression showed a positive relationship with the AQP4 protein expression during the astrocytes edema formation (r > 0.8369, P < 0.05). Hyponotic medium could induce cell edema and expression of AQP4mRNA and protein increased, and vibility of astrocytes inhibited. The AQP4 expression showed a positive relationship with the osmolality. The results suggest that AQP4 participated in the brain edema formation.

Effect of Maternal Hydration on Oligohydramnios

In Brief Objective To determine the effect of maternal hydration with intravenous (IV) isotonic fluid, IV hypotonic fluid, and oral water on amniotic fluid index (AFI) in women with oligohydramnios. Methods Patients with low AFI and gestational age over 35 weeks without maternal complications were randomized into four groups (2 L/2 h IV isotonic fluid, 2 L/2 h IV hypotonic fluid, 2 L/2 h oral water, control). Maternal plasma osmolality, AFI, hematocrit, and hemoglobin concentration were measured before and after hydration. Results Eighty-four patients (n = 21/group) completed the study without any maternal adverse effects. The mean increase in AFI after hydration was significantly greater in the IV hypotonic and oral water groups (2.8 ± 1.9, P < .001; 3.8 ± 1.9, P < .001, respectively), but not in the IV isotonic group (0.5 ± 1.1), compared with the control group (0.5 ± 1.1). Significant decreases in maternal hematocrit and hemoglobin concentration were found only after IV isotonic hydration (32.0 ± 2.9 to 29.5 ± 2.3, P < .001; 11.0 ± 1.6 to 10.1 ± 1.4, P < .001, respectively). Changes in maternal osmolality correlated with the changes in AFI in both the IV hypotonic group (r = .58, P < .001) and oral water group (r = .63, P < .001). Conclusion Maternal hydration with either IV hypotonic fluid or oral water increases AFI in oligohydramnios. Maternal osmotic change rather than maternal volume expansion had a more direct impact on increasing amniotic fluid volume with short-term acute hydration. Maternal plasma osmotic change has a more profound impact on acute increase of amniotic fluid volume when compared with maternal volume expansion.

Effect of maternal hydration on oligohydramnios: a comparison of three volume expansion methods

Objective: To determine the effect of maternal hydration with intravenous (IV) isotonic fluid, IV hypotonic fluid, and oral water on amniotic fluid index (AFI) in women with oligohydramnios. Methods: Patients with low AFI and gestational age over 35 weeks without maternal complications were randomized into four groups (2 L/2 h IV isotonic fluid, 2 L/2 h IV hypotonic fluid, 2 L/2 h oral water, control). Maternal plasma osmolality, AFI, hematocrit, and hemoglobin concentration were measured before and after hydration. Results: Eighty-four patients ( n = 21/group) completed the study without any maternal adverse effects. The mean increase in AFI after hydration was significantly greater in the IV hypotonic and oral water groups (2.8 ± 1.9, P < .001; 3.8 ± 1.9, P < .001, respectively), but not in the IV isotonic group (0.5 ± 1.1), compared with the control group (0.5 ± 1.1). Significant decreases in maternal hematocrit and hemoglobin concentration were found only after IV isotonic hydration (32.0 ± 2.9 to 29.5 ± 2.3, P < .001; 11.0 ± 1.6 to 10.1 ± 1.4, P < .001, respectively). Changes in maternal osmolality correlated with the changes in AFI in both the IV hypotonic group ( r = .58, P < .001) and oral water group ( r = .63, P < .001). Conclusion: Maternal hydration with either IV hypotonic fluid or oral water increases AFI in oligohydramnios. Maternal osmotic change rather than maternal volume expansion had a more direct impact on increasing amniotic fluid volume with short-term acute hydration.

Psychomotor functioning in suicide attempters: An explorative study using the Resource Oriented Body Examination of Bunkan

Within physical therapy there is a tradition of focusing on body-oriented resources and psychomotor functioning. The aim of the present explorative study was to describe psychomotor functioning such as patterns of muscular tension, posture, resistance to passive movements, respiration, and reactions to palpation in a group of suicide attempters admitted to the Lund Suicide Research Center, Sweden. Fe-three consecutive patients were included in the study (28 women and 25 men; mean age, 42 years; standard deviation, 13; range, 21–80 years). The Resource Oriented Body Examination (ROBE) of Buncan was used to assess psychomotor functioning. In addition, some other tests were undertaken, such as laboratory tests (monoamine metabolites in cerebrospinal fluid and plasma cortisol after dexamethasone) and temperament ratings. Results indicated that the patients generally showed a high level of psychomotor disturbance as compared with reference values. The ROBE total score was significantly higher in patients who later completed suicide than in the non-completer group (P = 0.02). Two ROBE subgroups were identified. The hypotonic group (n = 19) showed a higher frequency of respiration disturbances (P = 0.01) than the hypertonic group (n = 34). The hypotonic subgroup also had a significantly higher rate of completed suicides at a follow-up 5 years later (P = 0.048). With regard to biochemical tests, the hypotonic group comprised significantly more cases with high levels of cortisol after dexamethasone (P = 0.02). In conclusion, controlled studies of psychomotor functioning in suicide attempters ought to be performed. In our opinion the results of the present study enerate interesting hypotheses.