Aporte de fluidos en el pacientes pediátricos hospitalizados / Fluid intake in hospitalized pediatric patients

El aporte de fluidos constituye un elemento central en la atención del paciente pediátrico hospitalizado, existiendo aún controversias acerca de cuál es la composición óptima, la dosis adecuada y la mejor estrategia para administrar los mismos. El propósito de este artículo de actualización es brindar al médico que se desempeña en las diferentes áreas de la internación pediátrica, conceptos y enfoques terapéuticos que lo ayuden en la asistencia de los pacientes que por diversos motivos requieren la administración de fluidos endovenosos. La recomendación de utilizar cristaloides en la reanimación es casi uniforme. Se observa una clara tendencia al uso de soluciones isotónicas balanceadas para la reposición del déficit previo y el aporte de fluidos de mantenimiento. En relación a la dosis y a la estrategia, es generalizada la recomendación de un enfoque más restrictivo en el aporte de volumen, aún en los pacientes con shock, donde es necesario lograr un balance entre una resucitación efectiva y el riesgo de sobrecarga de fluidos. Respecto a la administración de albúmina al 20% en el paciente crítico con hipoalbuminemia, la evidencia existente es escasa y no permite formular recomendaciones. Sin embargo, es frecuente su uso en la práctica asistencial

Intravenous fluids administration is a central element in the care of hospitalized pediatric patients, and there are still controversies about what is the optimal composition, the appropriate dose, and the best strategy for their administration. The purpose of this narrative review is to provide the physicians who works in the different areas of pediatric hospitalization, concepts and therapeutic approaches that help them in the care of patients who for diverse reasons require administration of intravenous fluids. The recommendation to use crystalloids in resuscitation is almost uniform. There is a clear trend towards the use of balanced isotonic solutions to replace the previous deficit and the supply of maintenance fluids. In relation to the dose and strategy, the recommendation of a more restrictive approach in volume administration is generalized, even in patients with shock, where it is necessary to strike a balance between effective resuscitation and the risk of fluid overload. Regarding the administration of 20% albumin in critically ill patients with hypoalbuminemia, the existing evidence is scarce and does not allow recommendations to be formulated. However, it is frequently used in healthcare practice

En respuesta al artículo «Uso de sueros hipotónicos en la prescripción de la fluidoterapia intravenosa de mantenimiento» / In response to the article «Use of hypotonic fluids in the prescription of maintenance intravenous fluid therapy»

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Gelling hypotonic polymer solution for extended topical drug delivery to the eye.

Eye-drop formulations should hold as high a concentration of soluble drug in contact with ocular epithelium for as long as possible. However, eye tears and frequent blinking limit drug retention on the ocular surface, and gelling drops typically form clumps that blur vision. Here, we describe a gelling hypotonic solution containing a low concentration of a thermosensitive triblock copolymer for extended ocular drug delivery. On topical application, the hypotonic formulation forms a highly uniform and clear thin layer that conforms to the ocular surface and resists clearance from blinking, increasing the intraocular absorption of hydrophilic and hydrophobic drugs and extending the drug-ocular-epithelium contact time with respect to conventional thermosensitive gelling formulations and commercial eye drops. We also show that the conformal gel layer allows for therapeutically relevant drug delivery to the posterior segment of the eyeball in pigs. Our findings highlight the importance of formulations that conform to the ocular surface before viscosity enhancement for increased and prolonged ocular surface contact and drug absorption.

Effect of intraoperative Hartmann's versus hypotonic solution administration on FLACC pain scale scores in children: A prospective randomized controlled trial.

BACKGROUND: In healthy children, an isotonic solution containing no glucose or a small amount of glucose (1-2%) has been recommended as an intraoperative maintenance fluid due to the potential risk of hyponatremia associated with hypotonic solutions. However, a hypotonic solution with glucose is still widely used as a maintenance fluid for pediatric anesthesia. We speculated that the hypotonic solution may worsen postoperative discomfort and irritability in pediatric patients due to hyponatremia. PATIENTS AND METHODS: In the current study, we compared the post-operative Face, Legs, Activity, Cry, Consolability(FLACC) scale scores of pediatric patients aged 3-10 years who received either a 1:2 dextrose solution or Hartmann's solution during Nuss Bar removal. RESULTS: The FLACC scale score in the post-anesthesia care unit was higher in the 1:2 dextrose solution group(HYPO) (n = 20) than in the Hartmann's solution group(ISO) (n = 20) (6.30 vs 4.70, p = 0.044, mean difference and 95% Confidence Interval(CI) was 1.6 (0.04 to 3.16)). We also compared opioid consumption at the post-anesthesia care unit. Total dose of fentanyl per body weight in the post-anesthesia care unit was also higher in the HYPO (0.59 vs 0.37 mcg/kg, p = 0.042, mean difference and 95% CI was 0.22 mcg/kg (0.030 to 0.402)). CONCLUSIONS: Intraoperative use of the hypotonic solution in children causes increased FLACC scale scores, leading to higher opioid consumption in post-anesthesia care unit.

Red blood cells under varying extracellular tonicity conditions: an optical tweezers combined with micro-Raman study.

Extracellular tonicity has a significant influence on human red blood cell deformation capability. Advancements in the area of laser physics and optical trapping have opened up a plethora of applications for understanding cell structure and dynamics. Here, Raman Tweezers technique was employed to investigate the impact of extracellular tonicity by exposing human red blood cells to both hypertonic and hypotonic intravenous fluids. Heme aggregation was observed in hypertonic saline solution, accompanied with damage in membrane protein. Loss of intracellular hemoglobin in hypotonic solution was evident from the decrease in porphyrin breathing mode present at 752 cm-1. Oxygen binding to the central iron in the red blood cell heme was also affected under both hyper/hypo tonicity conditions. Morphological deviation of discocytes to echinocytes/spherocytes were also evident from quantitative phase imaging. Principal component analysis have showed clear differentiation of samples in order to classify the control erythrocytes and the tonicity stressed erythrocytes. Present study has also demonstrated the application of Raman Tweezers spectroscopy as a potential tool for probing red blood cell under different stress conditions.

Risk factors for hyponatremia after hypotonic fluid infusion.

BACKGROUND: Hypotonic maintenance i.v. fluids (IVF) pose a higher risk of hyponatremia than isotonic maintenance IVF, but isotonic maintenance IVF can result in excess sodium (Na) load in children. This study analyzed the incidence and risk factors for hyponatremia in children given hypotonic fluids with different Na concentrations and different maintenance rates. METHODS: We performed a retrospective analysis using medical charts of children aged 3 months-15 years. The children were normonatremic (Na ≥135 mmol/L and <145 mmol/L) before IVF, and given IVF containing 35 mmol/L Na at a 100% maintenance rate (Na 35) or fluids containing 84 mmol/L Na at a 70% maintenance rate (Na 84) for 24-48 h. RESULTS: Of a total of 463 children, hyponatremia (Na <135 mmol/L) occurred in 46/275 children (17%) given Na 35, and 16/188 (9%) given Na 84 (P = 0.01). On multivariate logistic regression analysis, Na 35 (OR, 2.19; 95%CI: 1.04-4.62), low clinical dehydration scale (CDS) score before IVF (OR, 0.17; 95%CI: 0.06-0.49), and high body temperature 24-48 h after maintenance IVF (OR, 2.39; 95%CI: 1.79-3.18) were independent risk factors for hyponatremia. CONCLUSIONS: Maintenance IVF with low Na concentration at a 100% maintenance rate, low CDS before IVF, and a high body temperature 24-48 h after maintenance IVF are independent risk factors for hyponatremia.

Isotonic versus Hypotonic Intravenous Maintenance Fluids in Children: A Randomized Controlled Trial.

OBJECTIVE: To compare the incidence of hyponatremia during the first 48 h in hospitalized children receiving normal saline vs. N/2 saline as maintenance intravenous fluid. METHODS: This open label, randomized controlled trial to compare the incidence of hyponatremia in hospitalized children receiving normal saline (0.9% sodium chloride in 5% dextrose) vs. N/2 saline (0.45% sodium chloride in 5% dextrose) as maintenance fluid was conducted from December 2014 through November 2015 in a tertiary care teaching hospital. Children between 1 mo and 18 y requiring maintenance intravenous fluids were randomized to receive normal saline with 5% dextrose (n = 75) or N/2 saline with 5% dextrose (n = 75). RESULTS: Both groups were comparable for demographic variables and illness severity at baseline. Incidence of hyponatremia at 24 h of hospitalization was comparable between normal saline and N/2 saline group, 3(4%) vs. 6(8%) cases, respectively; p value 0.494. Mean serum sodium levels were marginally higher in normal saline group (138.3 ± 6.0 mEq/L) as compared with N/2 saline group (135.1 ± 4.4 mEq/L) (p value <0.01) at 24 h of hospitalization. Incidence of hyponatremia at 48 h and hypernatremia at 24 and 48 h was comparable in two groups. CONCLUSIONS: The use of either N/2 saline or normal saline in sick children at standard maintenance fluid rates is associated with low but comparable incidence of hypo or hypernatremia in first 24 h of hospitalization. Both types of fluids appear acceptable in hospitalized sick children.

The impact of intravenous isotonic and hypotonic maintenance fluid on the risk of delirium in adult postoperative patients: retrospective before-after observational study.

PURPOSE: To assess the impact of intravenous isotonic and hypotonic maintenance fluid on the risk of delirium in adult postoperative patients, we conducted retrospective before-after study in a tertiary teaching hospital. METHODS: We examined all adult patients admitted ICU after an elective operation for head and neck cancer, or esophageal cancer from February 2014 to January 2017. From February 2014 to July 2015, patients were administered hypotonic fluid (sodium; 35 mmol/L) as the National Institute for Health and Care Excellence (NICE) have recommended. From August 2015 to January 2017, patients were administered isotonic fluid (sodium; 140 mmol/L). We defined the incidence of delirium as the primary outcome. The delirium was defined as the Intensive Care Delirium Screening Checklist during the ICU stay ≥ 4. A propensity score-matched model was used to adjust confounders. RESULTS: As postoperative intravenous maintenance fluid, hypotonic fluid was administered to 119 patients and isotonic fluid was administered to 92 patients. Among those total cohorts, the incidence of postoperative delirium in the hypotonic group was 21.8%, which was significantly higher than that (9.8%) in the isotonic group (p = 0.019). After propensity score matching, we selected 77 patients in each group. The incidence of delirium during the ICU stay in the hypotonic group was 26.0%, which was significantly higher than the incidence of 11.7% in the isotonic group (p = 0.023). CONCLUSIONS: In this study, the use of postoperative hypotonic maintenance fluid was associated with a higher risk of postoperative delirium than that when isotonic maintenance fluid was used.

[Use of hypotonic fluids in the prescription of maintenance intravenous fluid therapy]. / Uso de sueros hipotónicos en la prescripción de la fluidoterapia intravenosa de mantenimiento.

INTRODUCTION: Isotonic fluids, in most cases, are the safest way to dispense fluids intravenously. The aim of this study was to determine the prescription of maintenance intravenous fluids and to study possible associated factors. MATERIAL AND METHOD: A descriptive, cross-sectional, multi-centre study was performed. A questionnaire was sent nationwide to several healthcare providers via an on-line survey, sent by email through different Medical Scientific Societies, and the Official Spanish Medical Association, between December 2016 and December 2017. RESULTS: A total of 487 questionnaires were received, of which 456 were submitted by paediatricians. More than one quarter (28.95%) (95% CI; 24.77-33.13) of the paediatricians usually dispense hypotonic fluids and 81.14% (95% CI; 77.54-84.74) prescribe infusion rates based on the Holliday and Segar protocol. The general profile of paediatricians who prescribe hypotonic fluids intravenously in Spain are medical residents, paediatricians working in paediatric non-intensive care units, in private hospitals, and those who recognise that no consensus exists among their direct work colleagues regarding this subject. CONCLUSIONS: More than twenty-five per cent of all paediatricians in our country continue to use hypotonic fluids as maintenance intravenous fluid therapy. There might be several potential factors associated to this. These kind of studies provide evidence of the great difficulties in transferring scientific knowledge to clinical practice.

Safe correction of severe hyponatremia in patient with severe renal failure using continuous venovenous hemofiltration with modified sodium content in the replacement fluid.

Optimal treatment of severe hyponatremia in patients requiring dialysis is not known. Rapid correction with the use of different dialysis modalities can lead to osmotic demyelination syndrome. We described a safe correction of severe hyponatremia in a 42-year-old male patient requiring dialysis, who was treated with continuous venovenous hemofiltration using hypotonic replacement fluid which was prepared and adjusted on a daily basis.

Restrictive versus Liberal Fluid Therapy for Major Abdominal Surgery.

BACKGROUND: Guidelines to promote the early recovery of patients undergoing major surgery recommend a restrictive intravenous-fluid strategy for abdominal surgery. However, the supporting evidence is limited, and there is concern about impaired organ perfusion. METHODS: In a pragmatic, international trial, we randomly assigned 3000 patients who had an increased risk of complications while undergoing major abdominal surgery to receive a restrictive or liberal intravenous-fluid regimen during and up to 24 hours after surgery. The primary outcome was disability-free survival at 1 year. Key secondary outcomes were acute kidney injury at 30 days, renal-replacement therapy at 90 days, and a composite of septic complications, surgical-site infection, or death. RESULTS: During and up to 24 hours after surgery, 1490 patients in the restrictive fluid group had a median intravenous-fluid intake of 3.7 liters (interquartile range, 2.9 to 4.9), as compared with 6.1 liters (interquartile range, 5.0 to 7.4) in 1493 patients in the liberal fluid group (P<0.001). The rate of disability-free survival at 1 year was 81.9% in the restrictive fluid group and 82.3% in the liberal fluid group (hazard ratio for death or disability, 1.05; 95% confidence interval, 0.88 to 1.24; P=0.61). The rate of acute kidney injury was 8.6% in the restrictive fluid group and 5.0% in the liberal fluid group (P<0.001). The rate of septic complications or death was 21.8% in the restrictive fluid group and 19.8% in the liberal fluid group (P=0.19); rates of surgical-site infection (16.5% vs. 13.6%, P=0.02) and renal-replacement therapy (0.9% vs. 0.3%, P=0.048) were higher in the restrictive fluid group, but the between-group difference was not significant after adjustment for multiple testing. CONCLUSIONS: Among patients at increased risk for complications during major abdominal surgery, a restrictive fluid regimen was not associated with a higher rate of disability-free survival than a liberal fluid regimen and was associated with a higher rate of acute kidney injury. (Funded by the Australian National Health and Medical Research Council and others; RELIEF ClinicalTrials.gov number, NCT01424150 .).

Differential effects of isotonic and hypotonic 4% albumin solution on intracranial pressure and renal perfusion and function.

OBJECTIVES: Albumin is used to resuscitate trauma patients but may increase intracranial pressure (ICP). Its effects on renal blood flow and function are unknown. Our aim was to examine the effects of hypertonic albumin on ICP and renal function, and if any effects are due to the hypotonicity of the solution containing albumin or to albumin itself. DESIGN, SETTING AND SUBJECTS: Cross-over, randomised controlled experimental study of six adult Merino ewes in the animal facility of a research institute. METHOD: Sheep were implanted with flow probes around the pulmonary and renal arteries and an ICP monitoring catheter in a lateral cerebral ventricle. Conscious sheep received normal saline, commercially available hypotonic 4% albumin solution (4% Albumex [278 mOsm/kg]) or a novel isotonic 4% albumin solution (288 mOsm/kg), with at least 48 hours between each intervention. RESULTS: Commercial hypotonic albumin solution increased ICP (by 8.5 mmHg [SEM, 2.1 mmHg]; P < 0.01), but neither isotonic albumin solution nor saline significantly changed ICP. The increase in ICP with hypotonic albumin solution was associated with an increase in central venous pressure (CVP) (by 5.4 mmHg [SEM, 0.6 mmHg]; P < 0.001), but no significant changes in cardiac output or stroke volume. None of the infusions changed renal blood flow, plasma creatinine level, creatinine clearance or plasma or urinary electrolyte levels. CONCLUSION: Compared with saline or isotonic albumin solution, hypotonic albumin solution increased ICP and CVP, but did not alter arterial pressure, cardiac output renal blood flow or renal function. Our findings support the view that the tonicity of the albumin solution, rather than the albumin itself, is responsible for increasing ICP.

Hypotonicity-induced cell swelling activates TRPA1.

Hypotonic solutions can cause painful sensations in nasal and ocular mucosa through molecular mechanisms that are not entirely understood. We clarified the ability of human TRPA1 (hTRPA1) to respond to physical stimulus, and evaluated the response of hTRPA1 to cell swelling under hypotonic conditions. Using a Ca2+-imaging method, we found that modulation of AITC-induced hTRPA1 activity occurred under hypotonic conditions. Moreover, cell swelling in hypotonic conditions evoked single-channel activation of hTRPA1 in a cell-attached mode when the patch pipette was attached after cell swelling under hypotonic conditions, but not before swelling. Single-channel currents activated by cell swelling were also inhibited by a known hTRPA1 blocker. Since pre-application of thapsigargin or pretreatment with the calcium chelator BAPTA did not affect the single-channel activation induced by cell swelling, changes in intracellular calcium concentrations are likely not related to hTRPA1 activation induced by physical stimuli.

Incidence of hyponatraemia following the use of three different intravenous fluids in paediatric surgery.

BACKGROUND: It is a common practice to administer 4.3% dextrose in 0.18% saline peri-operatively and for routine fluid maintenance in the paediatric age group. Concerns have been expressed about the risk of hyponatraemia associated with the administration of hypotonic intravenous fluids, hence the need to re-evaluate our practice. This study aims to evaluate the relative incidence of intra-operative hyponatraemia following the use of isotonic and hyopotonic intravenous fluids. PATIENTS AND METHODS: This randomised double-blind clinical trial recruited consecutive American Society of Anaesthesiologists physical status Class I and II children aged between 6 months and 17 years scheduled for various minor elective surgical procedures. The patients received one of 3 intravenous infusions for intra-operative fluid management. Group I received 4.3% dextrose in 0.18 saline (n = 25), Group II received normal saline (n = 20) and Group III received Ringer's lactate (n = 20). Blood samples were collected before the surgery and at the end of surgery for serum electrolytes. RESULTS: One patient in each group developed moderate hyponatraemia intraoperatively. This constituted a 4% (1/25) incidence of intra-operative hyponatraemia among patients who had hypotonic maintenance fluid and a 5% (2/40) incidence in the isotonic maintenance groups. The incidence of hyponatraemia was therefore comparable between patients who had hypotonic and isotonic intra-operative maintenance fluids (P = 1.000). CONCLUSION: We conclude that healthy children who have intraoperative hypotonic maintenance fluids during minor elective surgeries are not exposed to the additional risk of hyponatraemia compared to those who have isotonic fluids. The study of a larger sample size is recommended to further validate our findings.

Introducing TOPMAST, the first double-blind randomized clinical trial specifically dedicated to perioperative maintenance fluid therapy in adults.

BACKGROUND: Although prescribed to every patient undergoing surgery, maintenance fluid therapy is a poorly researched part of perioperative fluid therapy. The tonicity of the chosen solutions, could be an important cause of morbidity, with hyponatremia being a potential side effect of hypotonic solutions, where isotonic solution could lead to fluid overload. METHODS: The TOPMAST-trial is an ongoing prospective single-center double-blind randomized trial comparing an isotonic and a hypotonic maintenance fluid strategy during and after surgery in patients undergoing different types of major thoracic surgery. Patients receive NaCl 0.9% in glucose 5% with an added 40 mmol L-1 of potassium chloride or a premixed solution containing 54 mmol L-1 sodium, 55 mmol L-1 chloride and 26 mmol of potassium at a rate of 27 mL per kg of body weight per day. The primary hypothesis is that isotonic maintenance solutions cause a more positive perioperative fluid balance than hypotonic fluids. Different secondary safety endpoints will be explored, especially the effect of the study treatments on the occurrence electrolyte disturbances (e.g. hyponatremia, hyperchloremia) and a set of clinical endpoints. Efficacy endpoints include the need for resuscitation fluids and assessment of renal and hormonal adaptive mechanisms. An anticipated 68 patients will be included between March 2017 and January 2018. DISCUSSION: The study will provide the most comprehensive evaluation of clinically important outcomes associated with the choice of perioperative maintenance fluid therapy.

Comparison of the incidences of hyponatremia in adult postoperative critically ill patients receiving intravenous maintenance fluids with 140 mmol/L or 35 mmol/L of sodium: retrospective before/after observational study.

PURPOSE: The purpose of this study was to compare the incidences of hyponatremia in adult postoperative critically ill patients receiving isotonic and hypotonic maintenance fluids. METHODS: In this single-center retrospective before/after observational study, we included patients who had undergone an elective operation for esophageal cancer or for head and neck cancer and who received postoperative intensive care for >48 h from August 2014 to July 2016. In those patients, sodium-poor solution (35 mmol/L of sodium; Na35) had been administered as maintenance fluid until July 2015. From August 2015, the protocol for postoperative maintenance fluid was revised to the use of isotonic fluid (140 mmol/L of sodium; Na140). The primary outcome was the incidence of hyponatremia (<135 mmol/L) until the morning of postoperative day (POD) 2. RESULTS: We included 179 patients (Na35: 87 patients, Na140: 92 patients) in the current study. The mean volume of fluid received from ICU admission to POD 2 was not significantly different between the two groups (3291 vs 3337 mL, p = 0.84). The incidence of postoperative hyponatremia was 16.3% (15/92) in the Na140 cohort, which was significantly lower than that of 52.9% (46/87) in the Na35 group (odds ratio = 0.17, 95% confidence interval 0.09-0.35, p < 0.001]. The incidences of hypernatremia, defined as serum sodium concentration >145 mmol/L, were not significantly different between the two groups. CONCLUSION: In this study, the use of intravenous maintenance fluid with 35 mmol/L of sodium was significantly associated with an increased risk of hyponatremia compared to that with 140 mmol/L of sodium in adult postoperative critically ill patients.

Regulation of osmolality for cancer treatment.

Disseminated metastasis is associated with a poor prognosis, and its management in the peritoneal or pleural cavity is crucial in the treatment of cancer. Recent studies show that ion and water transporters play important roles in fundamental cellular functions, including the regulation of cell volume that would be involved in the cancer process. Here, we review the evidence for hypotonic treatments of cancer and evaluate the potential of the cellular physiological approach in clinical management. The regulation of extracellular osmolality is a promising method, with several studies demonstrating the cytocidal effects of hypotonic solution on cancer cells. Peritoneal lavage with distilled water (DW) during surgery is reported to improve the survival rate of patients with spontaneously ruptured hepatocellular carcinoma. The in vitro studies included in this review also indicate the cytocidal effects of hypotonic shock on esophageal, gastric, colonic, pancreatic, and liver cancer cells with several unique methods and apparatuses, such as a differential interference contrast microscope connected to a digital video camera, a high-resolution flow cytometer and re-incubation analysis. The in vivo studies demonstrate the safeness of a peritoneal injection of DW into mice and indicate that the development of dissemination nodules can be prevented by the pre-incubation of cancer cells with DW or the peritoneal injection of DW. We also demonstrate that the blockade of Cl- channels/transporters enhances the cytocidal effects of hypotonic shock by inhibiting regulatory volume decrease in various cancer cells. A deeper understanding of molecular mechanisms may lead to the discovery of these cellular physiological approaches as a novel therapeutic strategy for disseminated metastasis.

Hepatic and renal mechanisms underlying the osmopressor response.

Increased blood pressure (BP) is observed in patients with impaired baroreflexes after water drinking. The stimulus for this effect is low blood osmolality, and it has been termed the osmopressor response (OPR). The BP increase is associated with activation of the sympathetic nervous system and a requirement for transient receptor potential vanilloid 4 (TRPV4) channels. However, the mechanisms underlying the OPR are poorly understood. We tested the hypothesis that hypotonicity is sensed in the portal area to initiate the OPR. Sino-aortic denervated mice were used and BP was monitored for 30min after fluid infusion while mice were under anesthesia. Infusion of hypotonic fluid (0.45% saline), but not of isotonic 0.9% saline, directly into the portal vein, produced an immediate OPR (increase in BP with saline 0.45%: 15±13 vs. 0.9%: -7±2mmHg, p=0.003; AUC: 0.45%: 150±99, n=7 vs. 0.9%: -74±60mmHg·min, n=5, p=0.003). However, 0.45% saline was not able to trigger a similar response in TRPV4-/- mice (ΔBPTRPV4: -2±5mmHg, n=8, p=0.009). Hypotonic saline did not raise BP when infused at the same speed and volume into the jugular vein (jugular: -5±6mmHg, p=0.002, compared to portal). Denervation of the splanchnic nerve by celiac ganglionectomy (CGX) did not abolish the OPR (CGX: 15±11 vs. Sham: 16±6mmHg, p=0.34). Renal denervation diminished the OPR elicited by duodenal water infusion (denervation: 9±4 vs. sham: 31±15mmHg, p=0.016). Therefore, hypotonicity in the portal circulation, probably sensed by TRPV4 channels, triggers the OPR and intact renal nerves are needed for the full response.

Effects of pneumoperitoneum on severe hypernatremia in an adult patient who underwent laparoscopic surgery of hydatid cysts.

We describe the first case of severe hypernatremia associated to laparoscopic surgery for hydatid cyst in an adult patient after the use of hypertonic saline solution with complete resolution. Severe hypernatremia is an unusual fact at the immediate postoperative period but may have fatal consequences for the patient and need immediate action. The patient reached a serum sodium concentration of 179 mmol/L without adverse effects after 6 days of treatment. Laparoscopy could play a crucial role in Na+ absorption due to high intraabdominal pressure caused by the pneumoperitoneum and its limitations to avoid peritoneal absorption of hypertonic saline solution. The relation between this surgical technique and the severe complication is discussed. More experience is needed in terms of safety for the patient.