Albumin: a comprehensive review and practical guideline for clinical use.

PURPOSE: Nowadays, it is largely accepted that albumin should not be used in hypoalbuminemia or for nutritional purpose. The most discussed indication of albumin at present is the resuscitation in shock states, especially distributive shocks such as septic shock. The main evidence-based indication is also liver disease. In this review, we provided updated evidence-based instruction for definite and potential indications of albumin administration in clinical practice, with appropriate dosing and duration. METHODS: Data collection was carried out until November 2023 by search of electronic databases including PubMed, Google Scholar, Scopus, and Web of Science. GRADE system has been used to determine the quality of evidence and strength of recommendations for each albumin indication. RESULTS: A total of 165 relevant studies were included in this review. Fluid replacement in plasmapheresis and liver diseases, including hepatorenal syndrome, spontaneous bacterial peritonitis, and large-volume paracentesis, have a moderate to high quality of evidence and a strong recommendation for administering albumin. Moreover, albumin is used as a second-line and adjunctive to crystalloids for fluid resuscitation in hypovolemic shock, sepsis and septic shock, severe burns, toxic epidermal necrolysis, intradialytic hypotension, ovarian hyperstimulation syndrome, major surgery, non-traumatic brain injury, extracorporeal membrane oxygenation, acute respiratory distress syndrome, and severe and refractory edema with hypoalbuminemia has a low to moderate quality of evidence and weak recommendation to use. Also, in modest volume paracentesis, severe hyponatremia in cirrhosis has a low to moderate quality of evidence and a weak recommendation. CONCLUSION: Albumin administration is most indicated in management of cirrhosis complications. Fluid resuscitation or treatment of severe and refractory edema, especially in patients with hypoalbuminemia and not responding to other treatments, is another rational use for albumin. Implementation of evidence-based guidelines in hospitals can be an effective measure to reduce inappropriate uses of albumin.

Analysis of Fluid Replacement in Two Fluidic Chambers for Oblique-Incidence Reflectivity Difference (OI-RD) Biosensor.

Optical biosensors have a significant impact on various aspects of our lives. In many applications of optical biosensors, fluidic chambers play a crucial role in facilitating controlled fluid delivery. It is essential to achieve complete liquid replacement in order to obtain accurate and reliable results. However, the configurations of fluidic chambers vary across different optical biosensors, resulting in diverse fluidic volumes and flow rates, and there are no standardized guidelines for liquid replacement. In this paper, we utilize COMSOL Multiphysics, a finite element analysis software, to investigate the optimal fluid volume required for two types of fluidic chambers in the context of the oblique-incidence reflectivity difference (OI-RD) biosensor. We found that the depth of the fluidic chamber is the most crucial factor influencing the required liquid volume, with the volume being a quadratic function of the depth. Additionally, the required fluid volume is also influenced by the positions on the substrate surface bearing samples, while the flow rate has no impact on the fluid volume.

Organophosphorus Poisoning: Acute Respiratory Distress Syndrome (ARDS) and Cardiac Failure as Cause of Death in Hospitalized Patients.

Industrial production of food for animals and humans needs increasing amounts of pesticides, especially of organophosphates, which are now easily available worldwide. More than 3 million cases of acute severe poisoning are estimated to occur worldwide every year, and even more cases remain unreported, while 200,000-350,000 incidentally or intentionally poisoned people die every year. Diagnostic and therapeutic procedures in organophosphate poisoning have, however, remained unchanged. In addition to several neurologic symptoms (miosis, fasciculations), hypersecretion of salivary, bronchial, and sweat glands, vomiting, diarrhea, and loss of urine rapidly induce dehydration, hypovolemia, loss of conscience and respiratory distress. Within hours, signs of acidosis due to systemic hypoxia can be observed at first laboratory investigation after hospitalization. While determination of serum-cholinesterase does not have any diagnostic value, it has been established that hypoalbuminemia alone or accompanied by an increase in creatinine, lactate, or C-reactive protein serum levels has negative prognostic value. Increased serum levels of C-reactive protein are a sign of systemic ischemia. Protective mechanical ventilation should be avoided, if possible. In fact, acute respiratory distress syndrome characterized by congestion and increased weight of the lung, accompanied by heart failure, may become the cause of death. As the excess of acetylcholine at the neuronal level can persist for weeks until enough newly, locally synthesized acetylcholinesterase becomes available (the value of oximes in reducing this time is still under debate), after atropine administration, intravenous albumin and fluid infusion should be the first therapeutic interventions to reestablish normal blood volume and normal tissue oxygenation, avoiding death by cardiac arrest.

Effect on haemostasis of different replacement fluids during therapeutic plasma exchange-A comparative multicentre observational study.

INTRODUCTION: Therapeutic plasma exchange (TPE) is used for several chronic conditions with little evidence on the efficacy and safety of different choice of replacement fluid. Measurement of haemostasis, particularly in vitro thrombin generation, could play a role in determining the immediate efficacy of different fluid replacement. AIM: To determine the impact of different TPE replacement fluid regimens on haemostatic assays. METHODS: Prospective observational multi-centre cohort study in adult patients 18 years and older evaluating haemostatic changes between four different TPE regimens: (1) 5% human albumin solution (Alb) only, (2) 50:50 mix of 5% Alb + modified gelatin, (3) 70:30 mix of 5% Alb and normal saline (NS), and (4) solvent-detergent, virus-inactivated fresh frozen plasma (FFP) (either alone or combined with other fluids). Twenty-one haemostasis variables were analysed (procoagulant, anticoagulant and fibrinolytic factors) pre and post TPE sessions, including in vitro thrombin generation. Linear mixed modelling and canonical discriminant analyses were used to examine the effect of TPE fluid type on haemostatic variables. RESULTS: A total of 31 patients with up to 5 TPE sessions each (131 sessions in total) were enrolled. Out of 21 markers analysed using linear mixed modelling, the main effects of fluid type were found to be significant for 19 markers (P < 0.05), excluding plasminogen activator inhibitor-1 antigen and thrombin-anti-thrombin. Multivariate Analysis of Variance showed significant differences between the fluid types (Wilks' lambda = 0.07; F63,245.61  = 5.50; P < 0.0001) and this was supported by a canonical discriminant analysis, which identified the 4 most discriminating markers for fluid types as thrombin generation (lag-time, time-to Peak), fibrinogen and Factor V. In our analyses, the effect of FFP on haemostasis was significantly greater compared with other fluid types. Of the non-FFP fluids, 5% Alb + NS had a lower effect on haemostasis compared to other fluid types (Alb and modified gelatin + 5% Alb). CONCLUSION: Thrombin generation and fibrinogen discriminated better the effect of different TPE fluids on haemostasis and should be considered as potential markers to evaluate the immediate haemostatic effect of TPE procedures. The use of NS as a TPE replacement fluid had a distinctive impact on thrombin generation and fibrinogen responses compared to other non-FFP fluids.

The impact of modified fluid gelatin 4% in a balanced electrolyte solution on plasma osmolality in children-A noninterventional observational study.

BACKGROUND: Intravenous fluids for perioperative infusion therapy should be isotonic to maintain the body fluid homeostasis in children. Modified fluid gelatin 4% in a balanced electrolyte solution has a theoretical osmolarity of 284 mosmol L-1 , and a real osmolality of 264 mosmol kg H2 O-1 . Because both values are lower than those of 0.9% saline or plasma, gelatin would be expected to be hypotonic in-vitro and in-vivo. AIM: We thus hypothesized that the infusion of gelatin would be expected to decrease plasma osmolality. We performed an in-vitro experiment and an in-vivo study to evaluate the impact of gelatin on the osmolality in children. METHODS: In the in-vitro experiment, full blood samples were diluted with gelatin 4% or albumin (50 g L-1 ) from 0% (pure blood) to 100% (pure colloid), and the osmolality was measured by freezing-point depression. In the in-vivo study, blood gas analyses from children undergoing major pediatric surgery were collected before and after gelatin infusion, and the osmolality was calculated by a modified version of Zander's formula. RESULTS: In the in-vitro experiment, 65 gradually diluted blood samples from five volunteers (age 25-55 years) were analyzed. The dilution with gelatin caused no significant changes in osmolality between 0% and 100%. Compared with gelatin, the osmolality in the albumin group was significantly lower between 50% and 100% dilution (p < .05). In the in-vivo study, 221 children (age 21.4 ± 30 months) were included. After gelatin infusion, the osmolality increased significantly (mean change 4.3 ± 4.8 [95% CI 3.7-4.9] mosmol kg H2 O-1 ; p < .01) within a normal range. CONCLUSIONS: Gelatin in a balanced electrolyte solution has isotonic characteristics in-vitro and in-vivo, despite the low theoretical osmolarity, probably caused by the (unmeasured) negative charges in the gelatin molecules contributing to the plasma osmolality. For a better evaluation of the (real) tonicity of gelatin-containing solutions, we suggest to calculate the osmolality (mosmol kg H2 O-1 ) using Zander's formula. TRIAL REGISTRATION: ClinicalTrials.gov (ID: NCT02495285).

Personalized Hydration Requirements of Runners.

This study sought to (a) estimate how the duration of running influences sweat losses and contributes to the daily fluid requirement, and (b) empirically estimate the drinking rates required to prevent significant dehydration (≥2% body weight as body water). Individual sweating data and running duration were obtained from male (n = 83) and female (n = 36) runners (n = 146 total observations) performing under highly heterogeneous conditions and over a range of exercise durations (33-280 min). Running <60 min/day increased daily fluid needs by a factor of 1.3, whereas running >60 min/day increased the daily fluid need by a factor of 1.9-2.3. Running <60 min/day generally required no fluid intake to prevent significant dehydration before run completion (31/35 runners). In contrast, running >60 min/day required more than 50% replacement of sweating rates to prevent the same (65/111 runners). Overall sweat losses ranged from ∼0.2 to ∼5.0 L/day, whereas the drinking rates required to prevent significant dehydration ranged from 0 to 1.4 L/hr. The characterization of sweat losses, sweat rate, and required drinking among runners in this study indicate wide individual variability that warrants personalized hydration practices, particularly when running is prolonged (>60 min) and performance is important. This study may serve as a useful guidepost for sports dietitians when planning and communicating fluid needs to athletes, as well as complement guidance related to both personalized programmed and thirst-driven drinking strategies.

Fluid Therapy in Patients Undergoing Abdominal Surgery: A Bumpy Road Towards Individualized Management.

Prudent intraoperative fluid replacement therapy, inotropes, and vasoactive drugs should be guided by adequate hemodynamic monitoring. The study aimed to evaluate the single-centre practice on intraoperative fluid therapy in abdominal surgery (AS). The evaluation, based on a review of medical files, included 235 patients (103 men), aged 60 ± 15 years who underwent AS between September and November 2017. Fluid therapy was analyzed in terms of quality and quantity. There were 124 high-risk patients according to the American Society of Anaesthesiologists Classification (ASA Class 3+) and 89 high-risk procedures performed. The median duration of procedures was 175 (IQR 106-284) min. Eleven patients died post-operatively. The median fluids volume was 10.4 mL/kg/h of anaesthesia, including 9.1 mL/kg/h of crystalloids and 2.7 mL/kg/h of synthetic colloids. Patients undergoing longer than the median procedures received significantly fewer fluids than those who underwent shorter procedures. The volume of fluids in the longer procedures depended on the procedural risk classification and was significantly greater in high-risk patients undergoing high-risk surgery. Patients who died received significantly more fluids than survivors. In all patients, a non-invasive blood pressure monitoring was used and only six patients had therapy guided by metabolic equilibrium. The fluid therapy used was liberal but complied with the recommendations regarding the type of fluid and risk-adjusted dosing. Hemodynamic monitoring was suboptimal and requires modifications. In conclusion, the optimization of intraoperative fluid therapy requires a balanced and standardized approach consistent with treatment procedures.

Predicted sweat rates for group water planning in sport: accuracy and application.

This study tested the accuracy of a novel, limited-availability web application (H2Q™) for predicting sweat rates in a variety of sports using estimates of energy expenditure and air temperature only. The application of predictions for group water planning was investigated for soccer match play. Fourteen open literature studies were identified where group sweat rates were reported (n = 20 group means comprising 230 individual observations from 179 athletes) with fidelity. Sports represented included: walking, cycling, swimming, and soccer match play. The accuracy of H2Q™ sweat rates was tested by comparing to measured group sweat rates using the concordance correlation coefficient (CCC) with 95% confidence interval [CI]. The relative absolute error (RAE) with 95% [CI] was also assessed, whereby the mean absolute error was expressed relative to an acceptance limit of 0.250 L/h. The CCC was 0.98 [0.95, 0.99] and the RAE was 0.449 [0.279, 0.620], indicating that the prediction error was on average 0.112 L/h. The RAE was < 1.0 for 19/20 observations (95%). Drink volumes modeled as a proxy for sweat losses during soccer match play prevented dehydration (< 1% loss of body mass). The H2Q™ web application demonstrated high group sweat prediction accuracy for the variety of sports activities tested. Water planning for soccer match play suggests the feasibility of easily and accurately predicting sweat rates to plan group water needs and promote optimal hydration in training and/or competition.

Outcomes related to intravenous fluid administration in sickle cell patients during vaso-occlusive crisis.

While fluid replacement therapy is a primary treatment modality used in vaso-occlusive crises for sickle cell disease, data is limited on its safety, efficacy, and variability. We performed a retrospective analysis on 157 unique patient encounters from 49 sickle cell patients hospitalized with a vaso-occlusive episode at our institution from 2013 to 2017. The median length of hospital stay was 4 days (IQR 2-7). The mean total amount of intravenous fluid administered during the hospitalization was 7.4 L (Std 9.6). The mean total amount of fluid intake including intravenous fluids, blood transfusions, and oral fluids was 14.2 L (Std 18.2). Multivariate analyses revealed significant associations between the development of any adverse event (including a new oxygen requirement, acute chest syndrome, aspiration event, other hospital-acquired infection, acute kidney injury, and intensive care unit transfer) and the following variables: intravenous fluid administered in the first 24 h (p = 0.001, OR 1.899, 95% CI 1.319-2.733), total amount of intravenous fluid administered (p = 0.005, OR 1.081, 95% CI 1.023-1.141), and total amount of fluid intake including oral fluids, blood transfusions, and intravenous fluids (p = 0.009, OR 1.046, 95% CI 1.011-1.081). Other factors found to be significantly associated with any adverse event were dialysis dependence prior to admission (p < 0.001, OR 12.984, 95% CI 3.660-46.056) and admission to an inpatient service versus an emergency room or observation unit (p = 0.008, OR 3.201, 95% CI 1.346-7.612). While fluid administration may theoretically slow the sickling process, this data suggests that fluid administration during a vaso-occlusive episode, and especially total volume given in the first 24 h, may also lead to adverse events.

Optimal crystalloid volume ratio for blood replacement for maintaining hemodynamic stability and lung function: an experimental randomized controlled study.

BACKGROUND: Crystalloids are first line in fluid resuscitation therapy, however there is a lack of evidence-based recommendations on the volume to be administered. Therefore, we aimed at comparing the systemic hemodynamic and respiratory effects of volume replacement therapy with a 1:1 ratio to the historical 1:3 ratio. METHODS: Anesthetized, ventilated rats randomly included in 3 groups: blood withdrawal and replacement with crystalloid in 1:1 ratio (Group 1, n = 11), traditional 1:3 ratio (Group 3, n = 12) and a control group with no interventions (Group C, n = 9). Arterial blood of 5% of the total blood volume was withdrawn 7 times, and replaced stepwise with different volume rations of Ringer's acetate, according to group assignments. Airway resistance (Raw), respiratory tissue damping (G) and tissue elastance (H), mean arterial pressure (MAP) and heart rate (HR) were assessed following each step of fluid replacement with a crystalloid (CR1-CR6). Lung edema index was measured from histological samples. RESULTS: Raw decreased in Groups 1 and 3 following CR3 (p < 0.02) without differences between the groups. H elevated in all groups (p < 0.02), with significantly higher changes in Group 3 compared to Groups C and 1 (both p = 0.03). No differences in MAP or HR were present between Groups 1 and 3. Lung edema was noted in Group 3 (p < 0.05). CONCLUSIONS: Fluid resuscitation therapy by administering a 1:1 blood replacement ratio revealed adequate compensation capacity and physiological homeostasis similar with no lung stiffening and pulmonary edema. Therefore, considering this ratio promotes the restrictive fluid administration in the presence of continuous and occult bleeding.

The Use of Indomethacin with Complete Amniotic Fluid Replacement and Classic Hysterotomy for the Reduction of Perinatal Complications of Intrauterine Myelomeningocele Repair.

OBJECTIVE: This study presented outcomes of classical hysterotomy with modified antiprostaglandin therapy for intrauterine repair of foetal myelomeningocele (fMMC) performed in a single perinatal centre. STUDY DESIGN: Forty-nine pregnant women diagnosed with fMMC underwent classic hysterotomy with anti-prostaglandin management, complete amniotic fluid replacement and high dose indomethacin application. RESULTS: The average gestational age (GA) at delivery was 34.4 ± 3.4 weeks, with no births before 30 weeks GA. There were 2 foetal deaths. Complete reversal of hindbrain herniation (HH), assessed in magnetic resonance imaging at 30-31 weeks GA was found in 72% of foetuses (mostly with HH grade I prior to fMMC repair). Our protocol resulted in rare use of magnesium sulphate (6%), low incidence of chorioamniotic membrane separation - chorioamniotic membrane separation (6%), preterm premature rupture of membranes - preterm premature rupture of membranes (pPROM; 15%) and preterm labour - preterm labour (PTL; 17%). The postoperative wound continuity of the uterus was usually stable (in 72% of patients), with low frequency of scar thinning (23%). CONCLUSION: Our protocol results in rare use of tocolytics, and the low occurrences of CMS, pPROM and PTL in relation to other study cohorts: Management of Myelomeningocele Study, Children's Hospital of Philadelphia, and Vanderbilt University Medical Centre.

Fluid management in Acute Respiratory Distress Syndrome: A narrative review.

Acute Respiratory Distress Syndrome remains a major source of morbidity and mortality in the modern intensive care unit (ICU). Major advances in the understanding and management of this condition were made in the last two decades. The use of low tidal ventilation is a well-established therapy. Conservative fluid management is now another cornerstone of management. However, much remains to be understood in this arena. Assessing volume status in these patients may be challenging and the tools available to do so are far from perfect. Several dynamic measures including pulse pressures variation are used. Ultrasound of the lungs and the vascular system may also have a role. In addition, the type of fluid to administer when needed is still open to debate. Finally, supportive measures in these patients, early during their ICU stay and later after discharge continue to be crucial for survival and adequate recovery.

Effects of acute exercise, dehydration and rehydration on cognitive function in well-trained athletes.

This study investigated the effects of aerobic exercise, fluid loss and rehydration on cognitive performance in well-trained athletes. Ten endurance-trained males (25 ± 5 years; 175 ± 5 cm; 70.35 ± 5.46 kg; VO2max, 62.95 ± 7.20 ml · kg.min-1) lost ~2.5 ± 0.6% body mass via continuous cycling exercise at ~65% peak sustainable power output (60 min duration) before consuming different beverages (Water = W1 and W2, Sustagen Sport = SS, Powerade = PD) and food ad libitum on four separate occasions. Cognitive function using a four-choice reaction time task (CRT), body mass, fluid consumption volumes, urine samples and subjective ratings (alertness, concentration, energy) were obtained before and after exercise, and hourly during recovery (for 4 h). CRT latency was significantly reduced immediately after exercise compared to pre-exercise measures for all trials (W1 = -16 ± 18 ms, W2 = -22 ± 21 ms, PD = -22 ± 22 ms, SS = -19 ± 26 ms). However, this effect was short-lived with subsequent measures not different from pre-exercise values. No difference in CRT accuracy was observed at any time across all trials. Subjective ratings were not different at any time across all trials. Aerobic exercise, hypohydration or an interaction between these two may provide a small cognitive performance benefit. However, these effects are temporary and confined to the immediate post-exercise period.

Preemptive volume therapy to prevent hemodynamic changes caused by the beach chair position: hydroxyethyl starch 130/0.4 versus Ringer's acetate-a controlled randomized trial.

BACKGROUND: Hemodynamic instability frequently occurs in beach chair positioning for surgery, putting patients at risk for cerebral adverse events. This study examined whether preoperative volume loading with crystalloids alone or with a crystalloid-colloid combination can prevent hemodynamic changes that may be causative for unfavorable neurologic outcomes. METHODS: The study randomly assigned 43 adult patients undergoing shoulder surgery to 3 study groups. Each group received an infusion of 500 mL of Ringer's acetate between induction of anesthesia and being placed in the beach chair position. The crystalloid group received an additional bolus of 1000 mL Ringer's acetate. The hydroxyethyl starch group was administered an additional bolus of 500 mL of 6% hydroxyethyl starch 130/0.4. Hemodynamic monitoring was accomplished via an esophageal Doppler probe. Cerebral oxygen saturation was examined with near-infrared spectroscopy. Changes in stroke volume variation between the prone and beach chair positions were defined as the primary outcome parameter. Secondary outcomes were changes in cardiac output and cerebral oxygen saturation. RESULTS: The control group was prematurely stopped after enrollment of 4 patients because of adverse events. In the hydroxyethyl starch group, stroke volume variation remained constant during positioning maneuvers (P = .35), whereas a significant increase was observed in the Ringer's acetate group (P < .01; P = .014 for intergroup comparison). This was also valid for changes in cardiac output. Cerebral oxygen saturation significantly decreased in both groups. CONCLUSIONS: Preprocedural boluses of 500 mL of 6% hydroxyethyl starch 130/0.4 as well as 1000 mL of Ringer's acetate were efficient in preserving hemodynamic conditions during beach chair position.

Fluid replacement modulates oxidative stress- but not nitric oxide-mediated cutaneous vasodilation and sweating during prolonged exercise in the heat.

The roles of nitric oxide synthase (NOS), reactive oxygen species (ROS), and angiotensin II type 1 receptor (AT1R) activation in regulating cutaneous vasodilation and sweating during prolonged (≥60 min) exercise are currently unclear. Moreover, it remains to be determined whether fluid replacement (FR) modulates the above thermoeffector responses. To investigate, 11 young men completed 90 min of continuous moderate intensity (46% V̇o2peak) cycling performed at a fixed rate of metabolic heat production of 600 W (No FR condition). On a separate day, participants completed a second session of the same protocol while receiving FR to offset sweat losses (FR condition). Cutaneous vascular conductance (CVC) and local sweat rate (LSR) were measured at four intradermal microdialysis forearm sites perfused with: 1) lactated Ringer (Control); 2) 10 mM NG-nitro-l-arginine methyl ester (l-NAME, NOS inhibition); 3) 10 mM ascorbate (nonselective antioxidant); or 4) 4.34 nM losartan (AT1R inhibition). Relative to Control (71% CVCmax at both time points), CVC with ascorbate (80% and 83% CVCmax) was elevated at 60 and 90 min of exercise during FR (both P < 0.02) but not at any time during No FR (all P > 0.31). In both conditions, CVC was reduced at end exercise with l-NAME (60% CVCmax; both P < 0.02) but was not different relative to Control at the losartan site (76% CVCmax; both P > 0.19). LSR did not differ between sites in either condition (all P > 0.10). We conclude that NOS regulates cutaneous vasodilation, but not sweating, irrespective of FR, and that ROS influence cutaneous vasodilation during prolonged exercise with FR.

Plasmapheresis: A Retrospective Audit of Procedures from a Tertiary Care Center in Southern India.

INTRODUCTION: The term plasmapheresis/plasma exchange refers to the removal of the plasma component of blood and its replacement with various fluids. Plasma Exchange (PE) has been used to treat a variety of conditions that are associated with an aberrant immune response. We undertook this retrospective study aiming to look at plasmapheresis procedures conducted in the nephrology department over a fixed time period. MATERIALS AND METHODS: Retrospective analysis of PE procedures from January 2013 to October 2016 was conducted in the nephrology and Intensive Care Unit of a tertiary care teaching hospital. The goal was to achieve a total removal of 150-200 ml/plasma per kg body weight. As replacement, we used a standard protocol of 100 ml of 20% albumin in 1 L of normal saline and 2-3 units of fresh frozen plasma. All results were expressed as mean ± standard deviation and statistical analysis was done using the Student's t-test for continuous and Fisher's exact test for categorical data. RESULTS: A total of 192 procedures performed on 40 patients (22 males and 18 females). Age ranged from 15 to 79 years with a mean age of 37.5 years. Guillain-Barre syndrome accounted for 67.5% (>two-third of causes) for PE. Vascular access was femoral catheter in 27 (67.5%) and internal jugular catheter in 13 (32.5%). Mild hypotension occurred in 15 procedures (7.8%) of patients and allergic reactions such as rashes and chills occurred in 5 cycles (2.6%). A total of 36 patients (90%) showed significant improvement in condition, 2 did not show any change, while one worsened and one died due to respiratory complications. CONCLUSION: Our small series of data of plasmapheresis procedures from nephrology perspective has reaffirmed the safety and efficacy of the therapy in an experienced setup.

Influence of physical fitness of coronary disease patients on vagal reentry and heart rate recovery after exercise with and without fluid replacement.

BACKGROUND: Fluid replacement during exercise has been studied as an important strategy to enhance recovery, however, studies are needed to investigate the effect of this strategy in different physical profiles. The aim of the study was to investigate the influence of physical fitness of coronary artery disease (CAD) patients on vagal reentry and heart rate recovery after exercise performed with and without fluid replacement. METHODS: Nonrandomized crossover clinical trial. Thirty-three CAD patients were submitted to (I) cardiopulmonary exercise test: to divide the sample into lower and higher VO2  peak groups; (II) control protocol (CP): composed of rest, aerobic exercise and passive recovery; (III) hydration protocol (HP): composed of the same activities as the CP, but with water intake during exercise. The recovery was evaluated by vagal reentry and heart rate recovery immediately after exercise. RESULTS: The results did not show significant differences between the higher and lower VO2  peak groups. In addition, the hydration strategy adopted was not able to cause significant changes between control and HPs, regardless of group. However, a time effect was observed, suggesting anticipation of vagal reactivation and heart rate reduction in HP. CONCLUSIONS: Physical fitness did not influence vagal reentry and heart rate recovery in CAD patients after exercise. However, the hydration strategy seems to have anticipated vagal reentry and produced a more efficient reduction in heart rate regardless of the individuals' physical fitness, but these results should be analyzed with caution due to the absence of significant differences between groups and protocols.

Water drinking during aerobic exercise improves the recovery of non-linear heart rate dynamics in coronary artery disease: crossover clinical trial.

Introduction: The post-exercise recovery is a period of vulnerability of the cardiovascular system in which autonomic nervous system plays a key role in cardiovascular deceleration. It is already known that individuals with coronary artery disease (CAD) are at greater risk due to delayed vagal reactivation in this period. Water ingestion has been studied as a strategy to improve autonomic recovery and mitigate the risks during recovery. However, the results are preliminary and need further confirmation. Therefore, our aim was to investigate the influence of individualized water drinking on the non-linear dynamics of heart rate during and after aerobic exercise in CAD subjects. Methods: 30 males with CAD were submitted to a control protocol composed of initial rest, warming up, treadmill exercise, and passive recovery (60 min). After 48 hours they performed the hydration protocol, composed of the same activities, however, with individualized water drinking proportional to the body mass lost in the control protocol. The non-linear dynamics of heart rate were assessed by indices of heart rate variability extracted from the recurrence plot, detrended fluctuation analysis, and symbolic analysis. Results and discussion: During exercise, the responses were physiological and similar in both protocols, indicating high sympathetic activity and reduced complexity. During recovery, the responses were also physiological, indicating the rise of parasympathetic activity and the return to a more complex state. However, during hydration protocol, the return to a more complex physiologic state occurred sooner and non-linear HRV indices returned to resting values between the 5th and 20th minutes of recovery. In contrast, during the control protocol, only a few indices returned to resting values within 60 minutes. Despite that, differences between protocols were not found. We conclude that the water drinking strategy accelerated the recovery of non-linear dynamics of heart rate in CAD subjects but did not influence responses during exercise. This is the first study to characterize the non-linear responses during and after exercise in CAD subjects.