Thoracic Society of Australia and New Zealand position statement: The safe clinical use of sputum induction for bio-sampling of the lower airways in children and adults

Sputum induction is widely used in clinical settings for collection of biological samples from the lower airways. However, in recent years sputum induction has been associated with serious adverse events and even death. This position statement was commissioned by the Thoracic Society of Australia and New Zealand to address major adverse events of two deaths associated with sputum induction that have occurred in Australia in 2021, and outlines best practice for the safe use of sputum induction. The statement resulted from systematic literature searches by a multi-disciplinary group including respiratory physicians, nurses and physiotherapists (paediatric and adults focused). Consumers had input to an advanced draft of the position statement. The position statement covers indications for sputum induction, informed consent, scope of practice of personnel administering the procedure, infection control considerations, details about the sputum induction procedure, safety considerations and risk assessment in clinical settings.

Comparative-Effectiveness study evaluating outcomes for transforaminal epidural steroid injections performed with 3% hypertonic saline or normal saline in lumbosacral radicular pain

BACKGROUND

Transforaminal epidural steroid injection (TFESI) are commonly employed to treat lumbosacral radiculopathy. Despite anti-inflammatory properties, the addition of 3% hypertonic saline has not been studied.

OBJECTIVE

Compare the effectiveness of adding 0.9% NaCl (N-group) vs. 3% NaCl (H-group) in TFESI performed for lumbosacral radiculopathy.

METHODS

This retrospective study compared TFESI performed with lidocaine, triamcinolone and 0.9% NaCl. The primary outcome was the proportion of patients who experienced a ≥ 30% reduction in pain on a verbal rating scale (VRS; 0-100) at 3 months. Secondary outcome measures included the proportion of patients who improved by at least 30% for pain at 1- and 6-months, and who experienced ≥15% from baseline on the Oswestry disability index (ODI) at follow-up.

RESULTS

The H-group experienced more successful pain outcomes than the N-group at 3 months (59.09% vs. 41.51%; P = 0.002) but not at 1 month (67.53% vs. 64.78%; P = 0.61) or 6 months (27.13% vs 21.55%: P = 0.31). For functional outcome, there was a higher proportion of responders in the H-group than N-group at 3 months (70.31% vs. 53.46%; P = 0.002). Female, age ≤ 60 years and duration of pain ≤ 6 months were associated with superior outcomes at the 3-month endpoint. Although those with a herniated disc experienced better outcomes in general with TFESI, the only difference favoring the H-group was for spondylolisthesis patients.

CONCLUSIONS

3% hypertonic saline is a viable alternative to normal saline as an adjunct for TFESI, with randomized studies needed to compare its effectiveness to steroids as a possible alternative.

REGISTRATION

Thai Clinical Trials Registry ID TCTR 20231110006.

Hyperosmolar therapies for neurological deterioration in mild and moderate traumatic brain injury: towards new research

The scoping review by Nicolò Marchesini and colleagues about the use of hyperosmolar therapies (HTs) in patients with traumatic brain injury (TBI) points out a significant gap in scientific literature regarding this topic. Although there are few high-quality recommendations, it is important to provide care under certain physiologic parameters. Through this letter we comment on the importance of guidelines to administer and monitor the use of HTs in the Neuro-ICU.

Comparison of In Vitro Bacterial Susceptibility to Common and Novel Equine Wound Care Dressings

Antimicrobial resistance is becoming a problem of concern in the veterinary field, necessitating the use of effective topical treatments to aid the healing of wounds. Honey has been used for thousands of years for its medicinal properties, but in recent years medical-grade Manuka honey has been used to treat infected wounds. The goal of this study was to determine the relative susceptibility of four common equine wound pathogens to ten different types of antimicrobial agents based on the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The pathogens studied include ATCC lab-acclimated Pseudomonas aeruginosa, Escherichia coli, and methicillin-resistant Staphylococcus aureus and one from an equine sample submitted to the Colorado State Veterinary Diagnostic Laboratory (Streptococcus equi ssp. zooepidemicus (Streptococcus zooepidemicus)). An additional goal of the study was to describe the comparison of bactericidal activity of medical-grade Manuka honey, local honey, and commercial, food-grade honey to other commonly used wound dressings (20% hypertonic saline, silver sulfadiazine cream, PHMB gauze, and PHMB foam). The objective is to provide veterinary practitioners with comparative data on the use of a variety of antimicrobial dressings for inhibiting the growth of common wound bacteria. MIC and MBC for Manuka, store, and local honeys were comparable to those of sterile gauze, sugar, and hypertonic saline. Across bacterial species, local honey proved to have more bactericidal activity when compared to Manuka honey and commercial, food-grade honey. The MIC and MBC for PHMB gauze and foam was consistently at a higher dilution compared to the other antimicrobials. The majority of antimicrobials exhibited stronger inhibitory and bactericidal activity against a Streptococcus zooepidemicus isolate obtained from a wound compared to other bacteria that were ATCC lab-acclimated. Additional research for in vivo applications needs to be done to see whether differences exist in effective wound management.

Real-World Evaluation of the Safety and Effectiveness of 2.3% Hypertonic Saline Soft Mist Spray for Sino-Nasal Symptoms

Introduction and aims Mildly hypertonic saline is more effective in relieving symptoms of nasal congestion compared to placebo or isotonic saline. Recently, a unique device, delivering a soft mist of 2.3% hypertonic sea-salt saline (Nasoclear PureHaleTM; Zydus Healthcare Ltd., India) has been introduced in India. The device uses a power-less manual technique to release the saline as a soft mist at 1 ml/min. Methods This is a retrospective, multi-centric, single-arm study to evaluate the safety and effectiveness of 2.3% hypertonic sea-salt saline nasal irrigation delivered through a soft mist device in patients with sino-nasal symptoms. This is an analysis of data of 130 patients collected from the medical records of 11 practicing pediatricians across India. Results The mean age of the patients was 5.23 ± 4.24 years; 63 % were boys and 37% were girls (n = 130). The mean reduction in total nasal symptom score (TNSS) at follow-up from baseline was 6.28 ± 0.18 (median days = 7) (95% CI = 5.92 to 6.64; p<0.0001; mean TNSS at baseline = 7.75 ± 2.01, mean TNSS at follow-up = 1.47± 1.30). Out of 130 patients, 33 patients (25.3%) showed complete improvement in TNSS, 93 patients (71.5%) had ≥ 50% improvement in TNSS while 4 patients (3.07%) showed <50% improvement in TNSS. The effectiveness of the device was rated as excellent (75%-100% improvement) and very good (50%-75% improvement) in 41 and 74 patients, respectively. It was rated as very easy to use and easy to use by 62 patients and 57 patients, respectively. One hundred nineteen patients (91.5%) were compliant with the prescribed frequency of the device and 110 patients (84.6%) were compliant with the prescribed duration of use of the device. No serious adverse events were reported; two patients reported mild side effects - stinging and irritation of the throat. Conclusions The 2.3% hypertonic sea-salt saline nasal irrigation delivered through the soft mist device was found to be well-tolerated and effective in patients with sino-nasal symptoms in real-world clinical settings. Clinical trial number The clinical trial number of this study is CTRI/2022/07/043751.

Experimentally Induced Pain Results in Reduced Activity of the Rotator Cuff Muscles in Healthy Subjects

Shoulder pain is a complex, prevalent problem that is multifactorial in nature. While there are many potential causes, one common suspect is the rotator cuff musculature. The purpose of the present study was to induce pain in the supraspinatus muscle of healthy subjects and observe the resulting changes in muscle activity. Eight muscles on 23 subjects were assessed using electromyography: anterior, middle, and posterior deltoid; pectoralis major; upper trapezius; latissimus dorsi; serratus anterior; supraspinatus; and infraspinatus. It was hypothesized that the rotator cuff muscles would display reduced activity during pain, and that reductions in activity would remain after the pain had dissipated. Both of the rotator cuff muscles measured did indeed display reduced activity in a majority of the dynamic, isometric, and maximal contractions. Many of those reductions remained after the pain had subsided.

Effects and safety of hypertonic saline combined with airway clearance in non-hospitalized children with recurrent wheezing

Background

The International Study of Wheezing in Infants defines recurrent wheezing as the presence of three or more medically documented episodes of wheezing within one year. To date, there is no evidence on the use of hypertonic saline (HS) combined with airway clearance techniques (ACT) for children with recurrent wheezing treated in an outpatient setting. Therefore, this is the first study to explore the use of such interventions in infants with recurrent wheezing.

Objectives

To evaluate the effects and safety of a three-month protocol including HS and ACT for non-hospitalized infants with recurrent wheezing.

Methods

Randomized, double-blind, controlled trial, including outpatient infants with recurrent wheezing. Children were randomized to either 3% HS or 0.9% saline groups and were treated with bronchodilator and nebulized with the respective solutions before ACT. The primary outcome was the Wang score. Secondary outcomes included the number of hospitalizations and respiratory crisis, need for rescue medication, and school absences. All variables were measured during the three previous months from inclusion and during intervention period. The study protocol was registered at ClinicalTrials.gov (NCT04331496) on March, 31, 2020.

Results

Forty children were included. Regarding immediate effects, significant differences (p < 0 . 001 ) were found for time, but not for group or interaction (group × time), in all outcome variables (increase in SpO2, decrease in heart and respiratory rate, wheezing episodes, retraction, and Wang score). Comparing the previous three months with the study period, there were significant differences in both groups for the severity of crisis (p < 0 . 001 ) and medication steps (p = 0 . 002 ).

Conclusion

A three-month protocol including HS and ACT for outpatient infants with recurrent wheezing was safe and reduced morbidity. No differences were found between the use of HS and 0.9% saline.

Comparison of nebulised 3% hypertonic saline with ipratropium bromide in treatment of children with bronchiolitis: a randomized control trial

Introduction

Several drugs are in use for nebulization in children with acute bronchiolitis and no study has yet been conducted to compare the treatment outcome of nebulized ipratropium bromide and nebulized 3% hypertonic saline in Pakistan.

Objective

The objective was to compare the treatment outcome of nebulized hypertonic saline and ipratropium bromide in children with acute bronchiolitis.

Setting

Department of Pediatrics.

Study duration

October 2019 to March 2020.

Subjects and methods

A total of one hundred (n=100) children of either sex diagnosed with acute bronchiolitis were enrolled and randomized either to be nebulized with 3% hypertonic saline or ipratropium bromide. Outcomes were assessed in terms of respiratory rate, heart rate, and SpO2 and respiratory distress assessment instrument score at different time intervals, length of hospital stay, and need of admission.

Results

Respiratory rate and SPO2 improved significantly at 60 min and 24 h, respiratory distress assessment instrument improved significantly at 30 min, 60 min, and 24 h after the treatment in patients who were nebulized with hypertonic saline when compared to those nebulized with ipratropium bromide. The length of hospital stay was significantly shorter (2.63 vs. 3.82 days, P=0.008) and a lesser number of patients needed hospital admission (22% vs. 44%, P=0.019) in patients who were nebulized with hypertonic saline when compared to those nebulized with ipratropium bromide.

Conclusions

Nebulization with 3% hypertonic saline resulted in significant improvement in symptoms, a shorter duration of hospital stay, and a lesser number of hospital admissions as compared to nebulization with ipratropium bromide in children with acute bronchiolitis.

Diagnostic and Therapeutic Strategies to Severe Hyponatremia in the Intensive Care Unit

Hyponatremia is the most common electrolyte abnormality encountered in critically ill patients and is linked to heightened morbidity, mortality, and healthcare resource utilization. However, its causal role in these poor outcomes and the impact of treatment remain unclear. Plasma sodium is the main determinant of plasma tonicity; consequently, hyponatremia commonly indicates hypotonicity but can also occur in conjunction with isotonicity and hypertonicity. Plasma sodium is a function of total body exchangeable sodium and potassium and total body water. Hypotonic hyponatremia arises when total body water is proportionally greater than the sum of total body exchangeable cations, that is, electrolyte-free water excess; the latter is the result of increased intake or decreased (kidney) excretion. Hypotonic hyponatremia leads to water movement into brain cells resulting in cerebral edema. Brain cells adapt by eliminating solutes, a process that is largely completed by 48 h. Clinical manifestations of hyponatremia depend on its biochemical severity and duration. Symptoms of hyponatremia are more pronounced with acute hyponatremia where brain adaptation is incomplete while they are less prominent in chronic hyponatremia. The authors recommend a physiological approach to determine if hyponatremia is hypotonic, if it is mediated by arginine vasopressin, and if arginine vasopressin secretion is physiologically appropriate. The treatment of hyponatremia depends on the presence and severity of symptoms. Brain herniation is a concern when severe symptoms are present, and current guidelines recommend immediate treatment with hypertonic saline. In the absence of significant symptoms, the concern is neurologic sequelae resulting from rapid correction of hyponatremia which is usually the result of a large water diuresis. Some studies have found desmopressin useful to effectively curtail the water diuresis responsible for rapid correction.

Effect of Hypertonic Saline on Lung Function as Add-on Treatment in People With Cystic Fibrosis Receiving Dornase Alfa: A Cystic Fibrosis Foundation Patient Registry Analysis

BACKGROUND

Introduction of novel therapies for cystic fibrosis (CF) raises the question of whether traditional treatments can be withdrawn. Nebulized hypertonic saline (HS) potentially could be discontinued in patients receiving dornase alfa (DA).

RESEARCH QUESTION

In the era before modulators, did people with CF who are F508del homozygous (CFF508del) and who received DA and HS have better preserved lung function than those treated with DA only?

STUDY DESIGN AND METHODS

Retrospective analysis of the Cystic Fibrosis Foundation Patient Registry data (2006-2014). Among 13,406 CFF508del with data for at least 2 consecutive years, 1,241 CFF508del had spirometry results and were treated with DA for 1 to 5 years without DA or HS during the preceding (baseline) year. Absolute FEV1 % predicted change while receiving DA and HS, relative to treatment with DA only, was the main outcome. A marginal structural model was applied to assess the effect of 1 to 5 years of HS treatment while controlling for time-dependent confounding.

RESULTS

Of 1,241 CFF508del, 619 patients (median baseline age, 14.6 years; interquartile range, 6-53 years) received DA only and 622 patients (median baseline age, 14.55 years; interquartile range, 6-48.1 years) were treated with DA and HS for 1 to 5 years. After 1 year, patients receiving DA and HS showed FEV1 % predicted that averaged 6.60% lower than that in patients treated with DA only (95% CI, -8.54% to -4.66%; P < .001). Lower lung function in the former relative to the latter persisted throughout follow-up, highlighting confounding by indication. After accounting for baseline age, sex, race, DA use duration, baseline and previous year's FEV1 % predicted, and time-varying clinical characteristics, patients treated with DA and HS for 1 to 5 years were similar to those treated with DA only regarding FEV1 % predicted (year 1: mean FEV1 % predicted change, +0.53% [95% CI, -0.66% to +1.71%; P = .38]; year 5: mean FEV1 % predicted change, -1.82% [95% CI, -4.01% to +0.36%; P = .10]).

INTERPRETATION

In the era before modulators, CFF508del showed no significant difference in lung function when nebulized HS was added to DA for 1 to 5 years.

The Effect of Serum Electrolyte Levels and Infusion Treatments on the Development of Femoral Central Venous Catheter-Associated Deep Vein Thrombosis in Pediatric Intensive Care Unit

In this study, we aimed to determine the frequency of symptomatic central venous catheters-associated deep vein thrombosis (CVC-a DVT) among critically ill children with femoral vein implantation in our pediatric intensive care unit (PICU), and to compare the demographic factors, serum electrolyte levels, and types of the infusion treatments performed. A total of 215 patients aged 1 month to 18 years who had femoral CVC implanted between 2019 and 2021 were included in this study. The cases that were clinically symptomatic and had thrombosis diagnosed ultrasonography were accepted as CVC-a DVT (+), and the other cases were considered as CVC-a DVT (-). Of the total 215 cases, 57.2% (n = 123) were female and 42.8% (n = 92) were male. Catheters-associated deep vein thrombosis diagnosis were made in 9.8% of the cases (n = 21). The mean time to diagnose thrombosis in CVC-a DVT (+) cases was 8.33 ± 5.65 days. With regard to gender, age, blood type, intubation status, length of stay on mechanical ventilator, presence of extra hemodialysis catheter, acute and chronic disease status, number of days of PICU hospitalization, and Pediatric Risk of Mortality-3 scoring, no significant differences between CVC-a DVT (-) and CVC-a DVT (+) cases were observed (P > .05). The incidence of thrombosis in refugee cases was found to be significantly higher than in Turkish cases (P = .047; P < .05). There was no statistically significant difference between the groups in baseline, mean, and peak glucose, sodium, and magnesium values and who received magnesium, blood product, inotrope, and 3% hypertonic saline (HTS) infusion (P > .05). No effect of serum glucose, sodium, and magnesium levels on the development of CVC-a DVT was found. Magnesium, blood product, inotrope, and 3% HTS infusion treatments have not been shown to have an effect on the development of CVC-a DVT.

Efficacy of BREATHOX® Device Inhalation on Acute Symptoms Associated with COVID-19 (BREATH Study): A Randomized Pilot Clinical Trial

(1) Background: A high concentration of sodium chloride on in vitro cell culture leads to reduced SARS-CoV-2 replication. Therefore, our aim was to evaluate the effects of inhaling hypertonic NaCl particles (BREATHOX®) on the duration of COVID-19-induced acute symptoms. (2) Methods: A prospective, open label, randomized, standard of care-controlled group (SOC) pilot trial compared inhaled oral and nasal administered BREATHOX® (2.0 mg NaCl, particles size between 1-10 μm), with five or ten inhalations per day for ten days. The primary endpoint was the time to resolve COVID-19-related symptoms. Safety outcomes included adverse clinical and laboratory events. (3) Results: A total of 101 individuals were screened and 98 were randomly assigned to BREATHOX® ten sessions per day (Group 1; 33 patients), BREATHOX® five sessions per day (Group 2; 32 patients), or SOC (33 patients), and followed up for 28 days. There was an association with cough frequency after 10 days BREATHOX® compared to SOC [Group 1: hazard ratio (HR) 2.01, 95% confidence interval (CI) 1.06-3.81; Group 2: HR 2.17, 95% CI 1.17-4.04]. No differences between the groups for the reported symptoms' resolution time were seen after 28 days. After combining both BREATHOX® groups, the period to cough resolution 10 days after randomization was significantly lower than in SOC (HR 2.10, 95% CI 1.20-3.67). An adverse event occurred in 30% of Group 1, 36% of Group 2, and 9% in SOC individuals. One patient from SOC had a serious adverse event. Nasal burning, sore or itchy nose, and dry mouth were considered related to BREATHOX® use and resolved after stopping inhalations. (4) Conclusion: BREATHOX® inhalation is safe and may be effective in reducing the duration of COVID-19-induced coughing.

A Hypertonic Seawater Nasal Irrigation Solution Containing Algal and Herbal Natural Ingredients Reduces Viral Load and SARS-CoV-2 Detection Time in the Nasal Cavity

Nasal irrigation is thought to decrease the viral load present in the nasal cavity. Our aim was to assess the effect of a hypertonic seawater solution [with algal and herbal natural ingredients (Sinomarin^®)] on the viral load of nasopharynx in patients hospitalized with severe COVID-19 pneumonia. We conducted a prospective, randomized, controlled trial from June 2022 to December 2022. We allocated 56 patients with COVID-19 pneumonia into two groups (28 in each group)-the hypertonic seawater group [nasal irrigations with a hypertonic seawater solution (Sinomarin^®) every 4 h for 16 h per day, for two consecutive days] and the control group (no nasal irrigations). A second nasopharyngeal swab was collected 48 h after the baseline nasopharyngeal swab (8 h after the last wash in the hypertonic seawater group) to estimate the SARS-CoV-2 viral load as determined by cycle threshold (Ct) values. In the hypertonic seawater group, the mean Ct values significantly increased two days after the initial measurement [ΔCt 48-0 h = 3.86 ± 3.03 cycles, p < 0.001 (95%CI: 2.69 to 5.04)]. No significant differences in the Ct values were observed in the control group [ΔCt 48-0 h = -0.14 ± 4.29, p = 0.866 (95%CI: -1.80 to -1.52)]. At follow-up, 17 patients from the hypertonic seawater group had negative test results compared to only 9 patients from the control group (p = 0.03). Nasal irrigations with a hypertonic seawater solution containing algal and herbal natural ingredients significantly decreased nasopharyngeal viral load and the detection time of SARS-CoV-2 in the nasal cavity.

Optimizing Respiratory Therapy Resources by De-Implementing Low-Value Care

BACKGROUND

Our institution was experiencing a respiratory therapy staffing crisis during the COVID-19 pandemic, in part due to excessive workload. We identified an opportunity to reduce burden by limiting use of 3% hypertonic saline and/or N-acetylcysteine nebulizer therapies (3%HTS/NAC).

METHODS

Leveraging the science of de-implementation, we established a policy empowering respiratory therapists to discontinue 3%HTS/NAC not meeting the American Association for Respiratory Care (AARC) Clinical Practice Guideline: Effectiveness of Pharmacologic Airway Clearance Therapies in Hospitalized Patients.¹ After a 3-month period of educating physicians and advanced practice practitioners the policy went to into effect. Outcomes measured included monthly number of treatments, orders, and full-time employees associated with administering nebulized 3%HTS/NAC.

RESULTS

Post policy activation, the monthly mean 3%HTS/NAC treatments were significantly reduced to 547.5 ± 284.3 from 3,565.2 ± 596.4 (P < .001) as were the associated monthly mean of full-time employees, 0.8 ± 0.41 from 5.1 ± 0.86 (P < .001). The monthly mean 3%HTS/NAC orders also fell to 93.8 ± 31.5 from 370.0 ± 46.9 (P < .001). Monthly mean non-3%HTS/NAC treatments remained stable; post policy was 3,089.4 ± 611.4 and baseline 3,279.6 ± 695.0 (P = 1.0).

CONCLUSIONS

Implementing a policy that empowers respiratory therapists to promote adherence to AARC Clinical Guidelines reduced low-value therapies, costs, and staffing needs.

Efficacy of intraoperative hypertonic saline irrigation in seroma prevention after abdominal wall reconstruction procedures - a pilot cohort study

INTRODUCTION

Seromas refer to collections of fluid secreted into the so-called dead spaces when extensive dissection takes place. Various methods of preventing seroma have been reported in the literature but their outcomes are far from spectacular.

AIM

To verify the expected benefit on usage of IHSI (intra-operative hypertonic saline irrigation) in aspect of decreasing subcutaneous fluid secretion and decreased hospital stay in patients undergoing various abdominal wall reconstruction procedures.

MATERIAL AND METHODS

We conducted a cohort study of total 64 patients treated by two techniques and divided into 2 groups. In the first group (SUBLAY), we assessed patients undergoing abdominal wall reconstruction with the positioning mesh underneath the rectus muscles. Group was divided into two subgroups: control and experimental. In second group (ONLAY), we analysed patients who had undergone reconstruction procedure combined with abdominoplasty and placement of a mesh between the subcutaneous tissue and the fascia. Intervention consisted in administration of 20 mL of 10% hypertonic saline into subcutaneous tissue 10 min before definitive wound closure.

RESULTS

Mean drain output, starting from day 2 post-op, was significantly lower in the experimental subgroups of the ONLAY and SUBLAY compared to the respective control subgroups. This had a beneficial effect on shortening the time to drainage removal.

CONCLUSIONS

In the short-term results, we demonstrated that intraoperative hypertonic saline irrigation significantly decreased the amount of the drained fluid and shortened the hospital stay. Further multicentre studies in larger groups of patients are needed.

Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) Complicated by Generalized Tonic-Clonic Seizures After a Course of Antibiotics: A Case Report

Nitrofurantoin and cephalexin are commonly used antibiotics for treating urinary tract infections. Hyponatremia secondary to syndrome of inappropriate antidiuretic hormone secretion (SIADH) has been reported as a rare side effect of nitrofurantoin but has never been a reported side effect of cephalexin. We report a case of a 48-year-old female who developed severe hyponatremia complicated by generalized tonic-clonic seizures after a course of antibiotics (nitrofurantoin followed by cephalexin) used for treating a urinary tract infection. She presented to the emergency department with a one-week history of dizziness, nausea, fatigue, and listlessness. She also had a two-week history of persistent urinary frequency despite completing a course of nitrofurantoin followed by a course of cephalexin. While in the emergency department waiting room, she had two episodes of generalized tonic-clonic seizures. Immediate post-ictal blood test results revealed severe hyponatremia and lactic acidosis. Results were consistent with severe SIADH and she was subsequently managed with hypertonic saline and fluid restriction. She was discharged after 48 hours of admission when her serum sodium levels normalized. Though we believe that nitrofurantoin was the culprit drug, we still asked the patient to avoid future use of both nitrofurantoin and cephalexin. Healthcare providers need to be aware of antibiotic-induced SIADH when assessing patients with hyponatremia.

Hypertonic saline use in neurocritical care for treating cerebral edema: A review of optimal formulation, dosing, safety, administration and storage

PURPOSE

Current Neurocritical Care Society guidelines on the management of cerebral edema recommend hypertonic saline (HTS) over mannitol in some scenarios, but practical questions remain regarding the appropriate administration method, concentration/dose, monitoring to ensure safe use, and storage. The aim of this article is to address these practical concerns based on the evidence currently available.

SUMMARY

Many different hypertonic solutions have been studied to define the optimal hyperosmolar substance to relieve acute cerebral edema in patients with conditions such as acute ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage, and traumatic brain injury. Mannitol and HTS are the main hyperosmolar therapies in use in contemporary neurocritical care practice. Contemporary use of HTS has followed a circuitous path in regards to the practical aspects of dosing and formulation, with evidence mainly consisting of retrospective or observational data. The effectiveness of bolus doses of HTS to lower acutely elevated intracranial pressure is well accepted. Adverse events with use of HTS are often mild and non-clinically significant if appropriate monitoring of serum sodium and chloride concentrations is performed. Available evidence shows that peripheral administration of HTS is likely safe in certain circumstances. Timely utilization of HTS is complicated by regulatory requirements for safe storage, but with appropriate safeguards HTS can be stored in patient care areas.

CONCLUSION

HTS formulations, methods of administration, infusion rate, and storage vary by institution, and no practice standards exist. Central intravenous administration may be preferred for HTS, but peripheral intravenous administration is safe provided measures are undertaken to detect and prevent phlebitis and extravasation. The safe use of HTS is possible with proper protocols, education, and institutional safeguards in place.

Overcorrection and undercorrection with fixed dosing of bolus hypertonic saline for symptomatic hyponatremia

OBJECTIVE

Current guidelines recommend treating symptomatic hyponatremia with rapid bolus-wise infusion of fixed volumes of hypertonic saline regardless of body weight. We hypothesize that this approach is associated with overcorrection and undercorrection in patients with low and high body weight.

DESIGN

Single-center, retrospective cohort study.

METHODS

Data were collected on patients treated with ≥1 bolus 100 or 150 mL 3% NaCl for symptomatic hyponatremia between 2017 and 2021. Outcomes were overcorrection (plasma sodium rise > 10 mmol/L/24 h, > 18 mmol/L/48 h, or relowering therapy) and undercorrection (plasma sodium rise < 5 mmol/L/24 h). Low body weight and high body weight were defined according to the lowest (≤60 kg) and highest (≥80 kg) quartiles.

RESULTS

Hypertonic saline was administered to 180 patients and caused plasma sodium to rise from 120 mmol/L to 126.4 mmol/L (24 h) and 130.4 mmol/L (48 h). Overcorrection occurred in 32 patients (18%) and was independently associated with lower body weight, weight ≤ 60 kg, lower baseline plasma sodium, volume depletion, hypokalemia, and less boluses. In patients without rapidly reversible causes of hyponatremia, overcorrection still occurred more often in patients ≤ 60 kg. Undercorrection occurred in 52 patients (29%) and was not associated with body weight or weight ≥ 80 kg but was associated with weight ≥ 100 kg and lean body weight in patients with obesity.

CONCLUSION

Our real-world data suggest that fixed dosing of bolus hypertonic saline may expose patients with low and high body weight to more overcorrection and undercorrection, respectively. Prospective studies are needed to develop and validate individualized dosing models.

NaCl 3% bolus therapy as emergency treatment for severe hyponatremia: Comparison of 100 ml versus 250 ml

CONTEXT

The aim of initial treatment of severe hyponatremia is to rapidly increase serum sodium to reduce the complications of cerebral edema. The optimal strategy to achieve this goal safely is still under debate.

OBJECTIVE

To compare the efficacy and safety of 100 and 250 ml NaCl 3% rapid bolus therapy as initial treatment of severe hypotonic hyponatremia.

DESIGN

Retrospective analysis of patients admitted between 2017 and 2019.

SETTING

Teaching hospital in the Netherlands.

PATIENTS

130 adults with severe hypotonic hyponatremia, defined as serum sodium ≤ 120 mmol/L.

INTERVENTION

A bolus of either 100 ml (N = 63) or 250 ml (N = 67) NaCl 3% as initial treatment.

MAIN OUTCOME MEASURES

Successful treatment was defined as a rise in serum sodium ≥ 5 mmol/L within the first 4 hours after bolus therapy. Overcorrection of serum sodium was defined as an increase of more than 10 mmol/L in the first 24 hours.

RESULTS

The percentage of patients with a rise in serum sodium ≥ 5 mmol/L within 4 hours was 32% and 52% after a bolus of 100 and 250 ml, respectively (P=0.018). Overcorrection of serum sodium was observed after a median of 13 hours (range 9 - 17 hours) in 21% of patients in both treatment groups (P=0.971). Osmotic demyelination syndrome did not occur.

CONCLUSION

Initial treatment of severe hypotonic hyponatremia is more effective with a NaCl 3% bolus of 250 ml than of 100 ml and does not increase the risk of overcorrection.

Initial Diagnosis and Management of Acutely Elevated Intracranial Pressure

Acutely elevated intracranial pressure (ICP) may have devastating effects on patient mortality and neurologic outcomes, yet its initial detection remains difficult because of the variety of manifestations that it can cause disease states it is associated with. Several treatment guidelines exist for specific disease processes such as trauma or ischemic stroke, but their recommendations may not apply to other causes. In the acute setting, management decisions must often be made before the underlying cause is known. In this review, we present an organized, evidence-based approach to the recognition and management of patients with suspected or confirmed elevated ICP in the first minutes to hours of resuscitation. We explore the utility of invasive and noninvasive methods of diagnosis, including history, physical examination, imaging, and ICP monitors. We synthesize various guidelines and expert recommendations and identify core management principles including noninvasive maneuvers, neuroprotective intubation and ventilation strategies, and pharmacologic therapies such as ketamine, lidocaine, corticosteroids, and the hyperosmolar agents mannitol and hypertonic saline. Although an in-depth discussion of the definitive management of each etiology is beyond the scope of this review, our goal is to provide an empirical approach to these time-sensitive, critical presentations in their initial stages.

Mouth breathing, dry air, and low water permeation promote inflammation, and activate neural pathways, by osmotic stresses acting on airway lining mucus

Respiratory disease and breathing abnormalities worsen with dehydration of the upper airways. We find that humidification of inhaled air occurs by evaporation of water over mucus lining the upper airways in such a way as to deliver an osmotic force on mucus, displacing it towards the epithelium. This displacement thins the periciliary layer of water beneath mucus while thickening topical water that is partially condensed from humid air on exhalation. With the rapid mouth breathing of dry air, this condensation layer, not previously reported while common to transpiring hydrogels in nature, can deliver an osmotic compressive force of up to around 100 cm H2O on underlying cilia, promoting adenosine triphosphate secretion and activating neural pathways. We derive expressions for the evolution of the thickness of the condensation layer, and its impact on cough frequency, inflammatory marker secretion, cilia beat frequency and respiratory droplet generation. We compare our predictions with human clinical data from multiple published sources and highlight the damaging impact of mouth breathing, dry, dirty air and high minute volume on upper airway function. We predict the hypertonic (or hypotonic) saline mass required to reduce (or amplify) dysfunction by restoration (or deterioration) of the structure of ciliated and condensation water layers in the upper airways and compare these predictions with published human clinical data. Preserving water balance in the upper airways appears critical in light of contemporary respiratory health challenges posed by the breathing of dirty and dry air.

Patient-Specific Risk Factors Associated With the Development of Hyperchloremia in a Neurocritical Care Intensive Care Unit

BACKGROUND

Hypertonic sodium chloride (HTS) is used in intensive care unit (ICU) settings to manage cerebral edema, intracranial hypertension, and for the treatment of severe hyponatremia. It has been associated with an increased incidence of hyperchloremia; however, there is limited literature focusing on hyperchloremic risk in neurologically injured patients. Objective: The primary objective of this study was to determine risk factors associated with development of hyperchloremia in a neurocritical care (NCC) ICU population.

METHODS

This was a retrospective case-control study performed in an adult NCC ICU and included patients receiving HTS. The primary outcome was to evaluate patient characteristics and treatments associated with hyperchloremia. Secondary outcomes included acute kidney injury and mortality.

RESULTS

Overall, 133 patients were identified; patients who were hyperchloremic were considered cases (n = 100) and patients without hyperchloremia were considered controls (n = 33). Characteristics and treatments were evaluated with univariate analysis and a logistic regression model. In the multivariate model, APACHE II Score, initial serum osmolality, total 3% saline volume, and total 23.4% saline volume were significant predictors for hyperchloremia. In addition, patients with a serum chloride greater than 113.5 mEq/L were found to have a higher risk of acute kidney injury (AKI) (adjusted OR 3.15; 95% CI 1.10-9.04).

CONCLUSIONS

This study demonstrated APACHE II Score, initial serum osmolality, and total 3% and 23.4% saline volumes were associated with developing hyperchloremia in the NCC ICU. In addition, hyperchloremia is associated with an increased risk of AKI.

Efficacy of hypertonic saline versus isotonic saline among children with cystic fibrosis: A systematic review and meta-analysis

Background

Inhaled hypertonic saline (HS) reduces pulmonary exacerbations in patients with cystic fibrosis (CF) aged 6 or more years. However, the effectiveness of HS in improving clinical outcomes in younger children aged 6 or less years is not established. This study examines the efficacy of HS in younger CF patients.

Methods

Searches were conducted across three databases (Medline, Cochrane Central and EMBASE) from inception through July 2022. Randomized controlled trials assessing the impact of HS in younger CF patients were included. Trials involving only patients greater than 6 years or control group other than isotonic saline (IS) were excluded. Outcomes measured included lung clearance index (LCI), cystic fibrosis questionnaire (CFQ-R) score, spirometry measures, oxygen saturation, respiratory rate, height and weight. Outcomes were reported as mean differences (MDs) with 95% confidence intervals.

Results

Seven studies (n = 390 patients) were included in this review. HS significantly reduced the LCI (MD: -0.67; 95%CI, -1.05 to 0.29, P = 0.0006) compared to IS. In addition, HS was associated with significant improvements in height (MD: 2.23; 95%CI, -0.00 to 4.46, P = 0.05) and CFQ-R (MD: 4.30; 95%CI, 0.65-7.95, P = 0.02), but not in oxygen saturation (MD: -0.15; 95%CI, -0.54 to 0.25, P = 0.47), respiratory rate (MD: -0.21; 95%CI, -2.19 to 1.77, P = 0.83) or weight (MD: 0.70; 95%CI, -0.47 to 1.87, P = 0.24). Furthermore, HS did not significantly improve spirometry measures, including FEV₁ (MD: -0.11; 95%CI, -0.21 to 0.43, P = 0.51) and forced vital capacity (MD: 0.27; 95%CI, -0.49 to 1.04, P = 0.48), but significantly improved FEF_25-75 (MD: 0.12; 95% CI, 0.05-0.20; P = 0.002).

Discussion

Treatment with HS in younger children with CF improves lung clearance, symptoms and quality of life. FEF_25-75 may prove a more sensitive measure for assessing intervention related improvements in pediatric CF trials.

Conclusion

The findings support HS as a therapeutic method in CF-affected children.

Management of Hyponatremia in Heart Failure: Practical Considerations

Hyponatremia is commonly encountered in the setting of heart failure, especially in decompensated, fluid-overloaded patients. The pathophysiology of hyponatremia in patients with heart failure is complex, including numerous mechanisms: increased activity of the sympathetic nervous system and the renin-angiotensin-aldosterone system, high levels of arginine vasopressin and diuretic use. Symptoms are usually mild but hyponatremic encephalopathy can occur if there is an acute decrease in serum sodium levels. It is crucial to differentiate between dilutional hyponatremia, where free water excretion should be promoted, and depletional hyponatremia, where administration of saline is needed. An inappropriate correction of hyponatremia may lead to osmotic demyelination syndrome which can cause severe neurological symptoms. Treatment options for hyponatremia in heart failure, such as water restriction or the use of hypertonic saline with loop diuretics, have limited efficacy. The aim of this review is to summarize the principal mechanisms involved in the occurrence of hyponatremia, to present the main guidelines for the treatment of hyponatremia, and to collect and analyze data from studies which target new treatment options, such as vaptans.

Respiratory Syncytial Virus is the Most Common Causative Agent of Viral Bronchiolitis in Young Children: An Updated Review

BACKGROUND

Viral bronchiolitis is a common condition and a leading cause of hospitalization in young children.

OBJECTIVE

This article provides readers with an update on the evaluation, diagnosis, and treatment of viral bronchiolitis, primarily due to RSV.

METHODS

A PubMed search was conducted in December 2021 in Clinical Queries using the key terms "acute bronchiolitis" OR "respiratory syncytial virus infection". The search included clinical trials, randomized controlled trials, case control studies, cohort studies, meta-analyses, observational studies, clinical guidelines, case reports, case series, and reviews. The search was restricted to children and English literature. The information retrieved from the above search was used in the compilation of this article.

RESULTS

Respiratory syncytial virus (RSV) is the most common viral bronchiolitis in young children. Other viruses such as human rhinovirus and coronavirus could be etiological agents. Diagnosis is based on clinical manifestation. Viral testing is useful only for cohort and quarantine purposes. Cochrane evidence-based reviews have been performed on most treatment modalities for RSV and viral bronchiolitis. Treatment for viral bronchiolitis is mainly symptomatic support. Beta-agonists are frequently used despite the lack of evidence that they reduce hospital admissions or length of stay. Nebulized racemic epinephrine, hypertonic saline and corticosteroids are generally not effective. Passive immunoprophylaxis with a monoclonal antibody against RSV, when given intramuscularly and monthly during winter, is effective in preventing severe RSV bronchiolitis in high-risk children who are born prematurely and in children under 2 years with chronic lung disease or hemodynamically significant congenital heart disease. Vaccines for RSV bronchiolitis are being developed. Children with viral bronchiolitis in early life are at increased risk of developing asthma later in childhood.

CONCLUSION

Viral bronchiolitis is common. No current pharmacologic treatment or novel therapy has been proven to improve outcomes compared to supportive treatment. Viral bronchiolitis in early life predisposes asthma development later in childhood.

The Effect of Pre-Electroacupuncture on Nociceptive Discharges of Spinal Wide Dynamic Range Neurons in Rat

Purpose

Spinal wide dynamic range (WDR) neurons are well studied in pain models and they play critical roles in regulating nociception. Evidence has started to accumulate that acupuncture produces a good analgesic effect via activating different primary fibers with distinct intensities. The purpose of the present study was to compare the distinct intensities of pre-electroacupuncture (pre-EA) at local muscular receptive fields (RFs), adjacent or contralateral non-RFs regulating the nociceptive discharges of spinal WDR neurons evoked by hypertonic saline (HS).

Materials and Methods

Spinal segments of electrophysiological recording were identified by neural tracers applied at the left gastrocnemius muscle. The thresholds of Aβ (T_Aβ), Aδ (T_Aδ) and C (T_C) components of WDR neurons were measured to determine the intensity of pre-EA by extracellular recording. The discharges of WDR neurons induced by distinct intensities of pre-EA and 200 µL HS (6%) injection in left gastrocnemius muscle of rats were observed by extracellular recording.

Results

The spinal segments of WDR neurons were confirmed in lumbar (L)5-6 area according to the projective segments of dorsal root ganglion. T_Aβ, T_Aδ and T_C of WDR neurons was determined to be 0.5, 1, and 2 mA, respectively. The pre-EA with intensities of T_Aβ (P < 0.05), T_Aδ (P < 0.05), T_C (P < 0.05) or 2T_C (P < 0.01) at ipsilateral adjacent non-RFs significantly reduced the discharges of WDR neurons, while at local RFs only pre-EA of T_Aδ (P < 0.05), T_C (P < 0.05) and 2T_C (P < 0.01) could inhibit the nociceptive discharges. In addition, intensity of pre-EA at contralateral non-RFs should reach at least T_C to effectively inhibit the firing rates of WDR neurons (P < 0.01).

Conclusion

Pre-EA could suppress nociceptive discharges of WDR neurons and the inhibitory effects were dependent on the distinct intensities and locations of stimulation.

Catheter-associated deep vein thrombosis in children with severe traumatic brain injury: A single-center experience

BACKGROUND

This study was performed to describe the single-center experience of deep vein thrombosis (DVT) in children with severe traumatic brain injury (sTBI) who were mechanically ventilated with a central line, and to identify potentially modifiable risk factors. It was hypothesized that children with DVT would have a longer duration of central venous line (CVL) and a higher use of hypertonic saline (HTS) compared to those without DVT.

PROCEDURE/METHODS

This was a retrospective study of children (0-18 years) with sTBI, who were intubated, had a CVL, and a minimum intensive care unit (ICU) stay of 3 days. Children were analyzed by the presence or absence of DVT. HTS use was evaluated using milliliter per kilogram (ml/kg) of 3% equivalents. Univariable and multivariable logistic regression models were used to determine which factors were associated with DVT.

RESULTS

Seventy-seven children met inclusion criteria, 23 (29.9%) had a DVT detected in an extremity. On univariable analysis, children with DVT identified in an extremity had prolonged CVL use (14 vs. 8.5 days, p = .021) and longer duration of mechanical ventilation (15 vs. 10 days, p = .013). HTS 3% equivalent ml/kg was not different between groups. On multivariable analysis, mechanical ventilation duration was associated with DVT detection in an extremity, whereas neither CVL duration nor HTS use had an association.

CONCLUSIONS

There was a high incidence of extremity DVT detected in children with sTBI who received invasive mechanical ventilation and had a CVL. HTS administration was not associated with DVT detection in an extremity.

The Role of Hypertonic Saline in Ablative Radiofrequency of the Sacroiliac Joint: Observational Study of 40 Patients

BACKGROUND

The aim of this retrospective uncontrolled article is to illustrate a technique of neurotomy of the sensitive branches of S1 S2 S3 in RFA that appears to result in a better success rate and longer-lasting pain relief.

METHODS

40 patients were treated, 26 females and 14 males, with an average age of 74 (92-55). After the examination, the patients underwent an ultrasound-guided diagnostic block of the affected sacroiliac joint. Only patients who presented pain relief greater than 60% after the diagnostic block were candidates for the RFA procedure. The procedure was always performed in the operating room on an outpatient basis. After obtaining the best fluoroscopic visualization of the joint to be treated, two RFA cannulae were placed starting from the lower medial margin parallel to the SIJ to perform a bipolar RFA along the entire medial margin of the SIJ. Lidocaine 2% and hypertonic saline 2 mEq/mL were used for each RFA level. Patients were followed-up at 3, 6, 12, 18, and 24 months by evaluating the NRS and SF-12.

RESULTS

Patients reported extreme satisfaction with the procedure performed and reported a significant improvement in NRS and SF-12 at FU visits. No adverse events occurred.

CONCLUSIONS

Bipolar RFA treatment of the sacroiliac joint with the use of a hypertonic saline solution appears to improve the success of the method and its durability. We are inclined to believe that the use of hypertonic saline may significantly increase the lesion area and result in a greater effect on the sensory branches.

Efficacy and safety of hypertonic saline solutions fluid resuscitation on hypovolemic shock: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Fluid resuscitation is a fundamental intervention in patients with hypovolemic shock resulting from trauma. Appropriate fluid resuscitation in trauma patients could reduce organ failure, until blood components are available, and hemorrhage is controlled. We conducted a systematic review and meta-analysis assessing the effect of hypertonic saline/dextran or hypertonic saline for fluid resuscitation on patient outcomes restricted to adults with hypovolemic shock.

METHODS

We conducted a search of electronic information sources, including PubMed, Embase, Web of Science, Cochrane library and bibliographic reference lists to identify all randomized controlled trials (RCTs) investigating outcomes of crystalloids versus colloids in patients with hypovolemic shock. We calculated the risk ratio (RR) or mean difference (MD) of groups using fixed or random-effect models.

RESULTS

Fifteen studies including 3264 patients met our inclusion criteria. Survival to hospital discharge rate between research groups varied and amounted to 71.2% in hypertonic saline/dextran group vs. 68.4% for isotonic/normotonic fluid (normal saline) solutions (odds ratio [OR] = 1.19; 95% confidence interval [CI] 0.97-1.45; I2 = 48%; p = 0.09). 28- to 30-days survival rate for hypertonic fluid solutions was 72.8% survivable, while in the case of isotonic fluid (normal saline) - 71.4% (OR = 1.13; 95% CI 0.75-1.70; I2 = 43%; p = 0.56).

CONCLUSIONS

This systematic review and meta-analysis, which included only evidence from RCTs hypertonic saline/dextran or hypertonic saline compared with isotonic fluid did not result in superior 28- to 30-day survival as well as in survival to hospital discharge. However, patients with hypotension who received resuscitation with hypertonic saline/dextran had less overall mortality as patients who received conventional fluid.

Early Hyperchloremia and Outcomes After Severe Traumatic Brain Injury: Analysis of Resuscitation Outcomes Consortium Hypertonic Saline Trial

To investigate the effect of the occurrence of early hyperchloremia on death or severe disability at 180 days in patients with severe traumatic brain injury (TBI).

DESIGN

Post hoc analysis of Resuscitation Outcomes Consortium Hypertonic Saline (ROC HS)-TBI trial.

SETTING

A total of 114 North American emergency medical services agencies in the ROC.

PATIENTS

A total of 991 patients with severe TBI and Glasgow Coma Scale score of less than or equal to 8.

INTERVENTIONS

Prehospital resuscitation with single IV dose (250 cc) of 7.5% saline in 6% dextran-70, 7.5% saline (no dextran), or crystalloid.

MEASUREMENTS AND MAIN RESULTS

Patients with increased serum chloride concentrations (110 mmol/L or greater) 24 hours after randomization were identified. Hyperchloremia was graded into one or greater than or equal to 2 occurrences in the first 24 hours. Logistic regression analyses were performed to determine the effects of hyperchloremia on: 1) death or severe disability at 180 days and 2) death within 180 days after adjusting for confounders. Compared with patients without hyperchloremia, patients with greater than or equal to 2 occurrences of hyperchloremia had significantly higher odds of death or severe disability at 180 days (odds ratio [OR], 1.81; 95% CI, 1.19-2.75) and death within 180 days (OR, 1.89; 95% CI, 1.14-3.08) after adjustment for confounders. However, the total volume of fluids administered during the first 24 hours was an independent predictor of death within 180 days; therefore, after adding an interaction term between the total volume of fluids administered during the first 24 hours and greater than or equal to 2 occurrences of hyperchloremia, patients with greater than or equal to 2 occurrences of hyperchloremia had significantly higher odds of death within 180 days (OR, 2.35; 95% CI, 1.21-4.61 d) but not of composite outcome of death or severe disability at 180 days.

CONCLUSIONS

After modifying for the effect of the total volume of fluids administered during the first 24 hours, multiple occurrences of hyperchloremia in the first 24 hours were associated with higher odds of death within 180 days in patients with severe TBI.

Evaluation of striate keratopathy after manual small-incision cataract surgery and its final outcomes in a tertiary hospital

Purpose

To study the demographic profile, contributing and precipitating factors, the severity of striate keratopathy and its relation with endothelial cell count, and evaluate the final treatment outcome of striate keratopathy.

Methods: This observational

analytical cohort study was conducted on 75 patients developing striate keratopathy after MSICS in the immediate postoperative period. Demographic profile, preoperative risk factors, and intraoperative complications were evaluated retrospectively. Postoperatively, slit-lamp grading of striate keratopathy was done, and specular microscopy of both eyes was taken. Treatment of striate keratopathy was initiated, and patients were followed up for 6 to 10 weeks for improvement.

Results

Striate keratopathy was most commonly associated with surgeries performed by resident surgeons (92%), longer duration of surgery, associated predisposing factors, and intraoperative or postoperative complications. On postoperative day 1, the majority of patients had moderate and severe striate keratopathy (66% and 32%, respectively). It was associated with significant endothelial cell loss (ECL) at the final follow-up (P = 0.0016). Striate keratopathy resolved in 97.3% of patients, irrespective of the treatment with hypertonic saline. At 6 to 10 weeks, 92% of patients achieved a BCVA of ≥6/9.

Conclusion

A careful preoperative evaluation, adequate training of resident surgeons, meticulous surgical technique, and prompt management of postoperative complications can lead to a decrease in the incidence of striate keratopathy in the majority of cases. The use of hypertonic saline eye drops does not change the final outcome, and most cases resolve spontaneously during follow-up.

The Strategy of the Brain to Maintain the Force Production in Painful Contractions-A Motor Units Pool Reorganization

A common symptom in neuromuscular diseases is pain, which changes human movement in many ways. Using the decomposed electromyographic signal, we investigate the strategy of the brain in recruiting different pools of motor units (MUs) to produce torque during induced muscle pain in terms of firing rate (FR), recruitment threshold (RT) and action potential amplitude (MUAP_AMP). These properties were used to define two groups (G1/G2) based on a K-means clusterization method. A 2.0 mL intramuscular hypertonic (6%) or isotonic (0.9%) saline solution was injected to induce pain or act as a placebo during isometric and isokinetic knee extension contractions. While isometric torque decreases after pain induction with hypertonic solution, this does not occur in isokinetic torque. This occurs because the MUs re-organized after the injection of both solutions. This is supported by an increase in RT, in both G1 and G2 MUs. However, when inducing pain with the hypertonic solution, RT increase is exacerbated. In this condition, FR also decreases, while MUAP_AMP increases only for G1 MUs. Therefore, this study proposes that the strategy for maintaining force production during pain is to recruit MUs with higher RT and MUAP_AMP.

Hypertonic Saline for Severe Traumatic Brain Injury With Herniation: A Military Prehospital Case Report

Severe traumatic brain injury (sTBI) is a devastating injury with limited prehospital therapies available. The Joint Trauma System (JTS) Clinical Practice Guidelines recommend hypertonic saline (HTS) for casualties with sTBI and signs of impending or ongoing herniation (IOH), but its use by combat medics has never been reported in the literature. This report details the management of a pregnant patient with sTBI and signs of IOH, including the use of HTS, by US Air Force pararescumen in an austere prehospital setting. Treatment with HTS was followed by improvement in the patient's neurologic exam and successful evacuation to definitive care where her child was delivered alive. Additionally, we review the pathophysiology and signs of herniation, the mechanism of action of hyperosmotic therapies, and the rationale behind the use of HTS in the combat setting.

Intravital imaging of mucus transport in asthmatic mice using microscopic optical coherence tomography

Asthma is one of the most common chronic diseases. Mucus overproduction is consistently linked to asthma morbidity and mortality. Despite the knowledge of the importance of mucus, little data exists on how mucus is transported in asthma and the immediate effects of therapeutic intervention. We therefore used microscopic optical coherence tomography (mOCT) to study spontaneous and induced mucus transport in an interleukin-13 (IL-13) induced asthma mouse model and examined the effects of isotonic (0.9% NaCl) and hypertonic saline (7% NaCl) which are used to induce mucus transport in cystic fibrosis. Without intervention, no bulk mucus transport was observed by mOCT and no intraluminal mucus was detectable in the intrapulmonary airways by histology. Administration of ATP-g-S induced mucus secretion into the airway lumen, but did not result in bulk mucus transport in the trachea. Intraluminal secreted immobile mucus could be mobilized by administration of isotonic or hypertonic saline but hypertonic saline mobilized mucus more reliably than isotonic saline. Irrespective of saline concentration, the mucus was transported in mucus chunks. In contrast to isotonic saline solution, hypertonic saline solution alone was able to induce mucus secretion. In conclusion, mOCT is suitable to examine the effects of mucus-mobilizing therapies in vivo. Although hypertonic saline was more efficient in inducing mucus transport, it induced mucus secretion, which might explain its limited benefit in asthma patients.

Approach to the Patient: Hyponatremia and the Syndrome of Inappropriate Antidiuresis (SIAD)

Hyponatremia is the most common electrolyte disturbance seen in clinical practice, affecting up to 30% of acute hospital admissions, and is associated with significant adverse clinical outcomes. Acute or severe symptomatic hyponatremia carries a high risk of neurological morbidity and mortality. In contrast, chronic hyponatremia is associated with significant morbidity including increased risk of falls, osteoporosis, fractures, gait instability, and cognitive decline; prolonged hospital admissions; and etiology-specific increase in mortality. In this Approach to the Patient, we review and compare the current recommendations, guidelines, and literature for diagnosis and treatment options for both acute and chronic hyponatremia, illustrated by 2 case studies. Particular focus is concentrated on the diagnosis and management of the syndrome of inappropriate antidiuresis. An understanding of the pathophysiology of hyponatremia, along with a synthesis of the duration of hyponatremia, biochemical severity, symptomatology, and blood volume status, forms the structure to guide the appropriate and timely management of hyponatremia. We present 2 illustrative cases that represent common presentations with hyponatremia and discuss the approach to management of these and other causes of hyponatremia.

Hypertonic saline for severe symptomatic hyponatraemia: real-world findings from the UK

Objective

To evaluate 'real-world' safety and efficacy of the European Society of Endocrinology guidelines for the treatment of severe symptomatic hyponatraemia using hypertonic saline (HTS).

Design

Retrospective, observational, cohort study, examining the use of HTS for severe symptomatic hyponatraemia at Sheffield Teaching Hospitals between 2017 and 2020.

Methods

Patients were identified from pharmacy records and demographic, clinical, and treatment data extracted.

Results

Out of 112 patients (females:males = 61:51), the mean age ± s.d. was 66.3± 16.0 years and mean pre-treatment serum sodium ± s.d. was 113.8 ± 6.4 mmol/L. Overall, overcorrection rates at 24 and 48 h (>10 and >18 mmol/L) were 44.9 and 19.6%, respectively, while 19.6% of patients were treated for overcorrection. Above-target rise in sodium (>5 mmol/L) after first and second boluses was noted in 22.6 and 34.6% of patients, respectively. In-hospital and 12-month mortality was 7.1 and 18.7%, respectively, with no cases of osmotic demyelination. The mean venous blood gas (VBG) sodium was 1.9 mmol/L lower than paired serum sodium (n = 36) (113.6 ± 6.6 vs 115.7 ± 7.8 mmol/L).

Conclusion

We report real-world data demonstrating that a significant number of patients overcorrected using current guidelines. Also, several patients had above-target rise in sodium after one bolus of HTS, and sodium measurement should be considered before the second bolus unless ongoing severe symptoms persist. A point of care VBG sodium concentration was useful for this purpose. In addition to careful monitoring, a cautious but anticipatory overcorrection prevention strategy should be considered in the first 24 h.

Hyponatremia management among patients admitted to tertiary hospital: A retrospective evaluation

Objective:

The aim of this study is to compare the adherence to the guidelines in patients presenting with hyponatremia defined as a sodium (Na) level ⩽120 mEq/L, treated with 3% hypertonic saline or normal saline. The comparison included 3% hypertonic saline use, safe serum sodium increases within 24 and 48 h, frequency of hyponatremia-related complications, and length of stay.

Methods:

This retrospective observational study enrolled 122 patients with serum sodium ⩽120 mEq/L admitted to the Internal Medicine Department, King Abdulaziz Medical City, National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia, from January 2016 to December 2017. The patients were treated with either 3% hypertonic saline or normal saline.

Results:

Of the 122 patients, 105 (83.3%) received normal saline, and 17 (13.5%) received hypertonic saline. In the normal saline group, the mean serum sodium increase at 24 h was lower (6.60 ± 4.75) compared to the hypertonic saline group (9.24 ± 5.04). The length of stay was longer in the normal saline group (10.35 ± 13.90) compared to the hypertonic saline group (4.35 ± 3.39). A small proportion (8.7%) of the normal saline group had a serum sodium increase >12 mg/dL at 24 h compared to 29.4% for the hypertonic saline group, and the difference was statistically significant (p value = 0.013). Almost one-third of the sample (36%) presented with complications, the majority (77.3%, n = 34) had a serum sodium of ⩽115 mg/dL, and 22.7% (n = 10) with a serum sodium of 116–120 mg/dL (p value = 0.041).

Conclusion:

Despite the strong recommendation for 3% hypertonic saline use in severe hyponatremia, many practitioners still use normal saline, even in patients with serum sodium ⩽120 mEq/L. Normal saline showed some efficacy in managing hyponatremia in asymptomatic cases; however, severe cases may have a delayed correction, hyponatremia-related complications, and an extended length of stay.

Sugar or salt ("SOS"): A protocol for a UK multicentre randomised trial of mannitol and hypertonic saline in severe traumatic brain injury and intracranial hypertension

Hyperosmolar solutions are widely used to treat raised intracranial pressure following severe traumatic brain injury. Although mannitol has historically been the most frequently administered, hypertonic saline solutions are increasingly being used. However, definitive evidence regarding their comparative effectiveness is lacking. The Sugar or Salt Trial is a UK randomised, allocation concealed open label multicentre pragmatic trial designed to determine the clinical and cost-effectiveness of hypertonic saline compared with mannitol in the management of patients with severe traumatic brain injury. Patients requiring intensive care unit admission and intracranial pressure monitoring post-traumatic brain injury will be allocated at random to receive equi-osmolar boluses of either mannitol or hypertonic saline following failure of routine first-line measures to control intracranial pressure. The primary outcome for the study will be the Extended Glasgow Outcome Scale assessed at six months after randomisation. Results will inform current clinical practice in the routine use of hyperosmolar therapy as well as assess the impact of potential side effects. Pre-planned longer term clinical and cost effectiveness analyses will further inform the use of these treatments.

Peripheral IV Administration of Hypertonic Saline: Single-Center Retrospective PICU Study

OBJECTIVES

To determine the frequency and characteristics of complications of peripherally administered hypertonic saline (HTS) through assessment of infiltration and extravasation.

DESIGN

Retrospective cross-sectional study.

SETTING

Freestanding tertiary care pediatric hospital.

PATIENTS

Children who received HTS through a peripheral IV catheter (PIVC).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We conducted a single-center retrospective review from January 2012 to 2019. A total of 526 patients with 1,020 unique administrations of HTS through a PIVC met inclusion criteria. The primary endpoint was PIVC failure due to infiltration or extravasation. The indication for the administration of HTS infusion was collected. Catheter data was captured, including the setting of catheter placement, anatomical location on the patient, gauge size, length of time from catheter insertion to HTS infusion, in situ duration of catheter lifespan, and removal rationale. The administration data for HTS was reviewed and included volume of administration, bolus versus continuous infusion, infusion rate, infusion duration, and vesicant medications administered through the PIVC. There were 843 bolus infusions of HTS and 172 continuous infusions. Of the bolus administrations, there were eight infiltrations (0.9%). The continuous infusion group had 13 infiltrations (7.6%). There were no extravasations in either group, and no patients required medical therapy or intervention by the wound care or plastic surgery teams. There was no significant morbidity attributed to HTS administration in either group.

CONCLUSIONS

HTS administered through a PIVC infrequently infiltrates in critically ill pediatric patients. The infiltration rate was low when HTS is administered as a bolus but higher when given as a continuous infusion. However, no patient suffered an extravasation injury or long-term morbidity from any infiltration.

Dose-Dependent Pain and Pain Radiation after Chemical Stimulation of the Thoracolumbar Fascia and Multifidus Muscle: A Single-Blinded, Cross-Over Study Revealing a Higher Impact of Fascia Stimulation

Acute low back pain can be experimentally induced by injections of hypertonic saline into deep tissues of the back, such as fascia and muscle. The current study investigated the dose-dependency of peak-pain and spatial extent of concomitant radiating pain following 50, 200 and 800 μL bolus injections of hypertonic saline (5.8%) into the thoracolumbar fascia and multifidus muscle, since data on dose-dependency is lacking in humans. Sixteen healthy subjects rated (11 female, 5 male; 23.3 ± 3.1 years, mean ± SD) intensity and spatial extent of pain. Injections into the fascia resulted in significantly higher peak-pain (+86%, p < 0.001), longer pain durations (p < 0.05), and larger pain areas (+65%, p < 0.02) and were less variable than intramuscular injections. Peak-pain ratings and pain areas were 2−3-fold higher/larger for 200 μL vs. 50 μL. In contrast, peak pain increased only marginally at 800 μL by additional 20%, while pain areas did not increase further at all in both, fascia and muscle. Thus, higher injection volumes did also not compensate the lower sensitivity of muscle. Peak-pain ratings and pain areas correlated between fascia and muscle (r = 0.530, p < 0.001 and r = 0.337, p < 0.02, respectively). Peak-pain ratings and pain areas correlated overall (r = 0.490, p < 0.0001), but a weak correlation remained when the impact of between-tissue differences and different injection volumes were singled out (partial r = 0.261, p < 0.01). This study shows dose-dependent pain responses of deep tissues where an injection volume of 200 μL of hypertonic saline is deemed an adequate stimulus for tissue differentiation. We suggest that pain radiation is not simply an effect of increased peripheral input but may afford an individual disposition for the pain radiation response. Substantially higher pain-sensitivity and wider pain areas support fascia as an important contributor to non-specific low back pain.

Clinical effects of hypertonic saline boluses in children with severe traumatic brain injury

AIM

To quantify the effects of 3% hypertonic saline (HTS) boluses on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in children.

METHODS

A retrospective study of patients admitted to a regional neurosurgical children's intensive care unit.

RESULTS

A total of 156 HTS boluses were given to children with traumatic brain injury. ICP decreased 6 mmHg (P < 0.01) and CPP increased 4 mmHg (P = 0.003) 1-h post-bolus. Effects persisted for 3 h post-dose ICP was 5 mmHg lower) and 4 h post-bolus CPP was 3 mmHg higher. ICP change was not associated with pre-bolus serum sodium concentration.

CONCLUSIONS

Hypertonic saline 3% at 5 mL/kg is an effective osmolar therapy for reducing ICP and increasing CPP in children for up to 3 h. '53-53' is a suitable guide - 5 mL/kg of 3% HTS will on average decrease ICP by at least 5 mmHg for 3 h. Pre-bolus serum sodium concentration is not correlated with effect size.

The management of acute and chronic hyponatraemia

Hyponatraemia is the most common electrolyte abnormality encountered in clinical practice; despite this, the work-up and management of hyponatraemia remain suboptimal and varies among different specialist groups. The majority of data comparing hyponatraemia treatments have been observational, up until recently. The past two years have seen the publication of several randomised control trials investigating hyponatraemia treatments, both for chronic and acute hyponatraemia. In this article, we aim to provide a background to the physiology, cause and impact of hyponatraemia and summarise the most recent data on treatments for acute and chronic hyponatraemia, highlighting their efficacy, tolerability and adverse effects.

Assessment of hemostasis in dogs with gastric-dilation-volvulus, during resuscitation with hydroxyethyl starch (130/0.4) or hypertonic saline (7.5%)

OBJECTIVE

To compare the impact of an IV bolus of hydroxyethyl starch 130/0.4 (HES) or hypertonic saline 7.5% (HS) on hemostasis in dogs resuscitated for gastric-dilation-volvulus (GDV).

DESIGN

Open-label, parallel-group randomized clinical trial.

ANIMALS

Twenty-three client-owned dogs.

INTERVENTIONS

Dogs affected by GDV and shock were randomly assigned to receive HES at 10 mL/kg or HS at 4 mL/kg every 15 minutes. Blood samples were collected for blood gas analysis, PCV, total plasma protein, albumin, standard coagulation profile, and thromboelastometry (ROTEM) at baseline (T0) and at the end of bolus (T1). To assess the differences between the 2 groups at T1, Student's t-test or Wilcoxon rank-sum test was used. To evaluate the differences between T0 and T1, ANOVA for paired data or Wilcoxon matched-pairs signed-ranks test was used. P < 0.05 was considered significant.

MEASUREMENT AND MAIN RESULTS

Hemostasis was evaluated by means of prothrombin time, activated partial thromboplastin time, fibrinogen, and ROTEM. The study included 13 dogs in the HES group and 10 dogs in the HS group. Differences were found between groups at T1: increase in clotting time (P = 0.018) and decrease in fibrinogen level (P = 0.021) in the HS-treated group. Between T0 and T1, there were differences for the HES group: increase in clot formation time (P = 0.046), decrease in maximum clot firmness (P = 0.002) in ex-TEM profile, and decrease in maximum clot firmness (P = 0.0117) in fib-TEM profile. Between T0 and T1, the following differences were noted for the HS group: increase in clotting time (P = 0.048) and clot formation time (P = 0.0019), decrease in maximum clot firmness (P = 0.031) and α angle (P = 0.036) in ex-TEM profile, decrease in α angle (P = 0.036) in in-TEM profile, and decrease in maximum clot firmness (P = 0.017) in fib-TEM profile.

CONCLUSION

In dogs affected by GDV, HES or HS infusion caused a similar tendency toward hypocoagulability, with few differences between the 2 groups.

In Vitro Comparison of Different Nebulizers Delivering 7% Hypertonic Saline

BACKGROUND

Nebulized 7% hypertonic saline is used to treat patients with cystic fibrosis. Clinical trials supporting its use were conducted with breath-enhanced nebulizers (BEN). It is not uncommon for the specific nebulizer used in studies or prescribed by a physician to be unavailable to patients. The investigator compared the aerosol characteristics of hypertonic saline delivered by nebulizers of different operating principles.

METHODS

A continuous-output nebulizer (CON), a breath-actuated (BAN) jet nebulizer, and 2 brands of BEN (Pari LC Plus and Sidestream Plus) were tested. Airway delivery and aerosol characteristics of nebulizers loaded with 7% hypertonic saline were determined with 3 breathing simulations (ie, infant, child, and adult breathing patterns) and cascade impaction, respectively. Solutes were analyzed with freezing point osmometry.

RESULTS

Aerosols generated with the BEN and BAN had similar mass median aerodynamic diameters (3.43-3.67 µm), geometric standard deviations (2.12-2.34), percentage of particles < 5 µm (63.1-68.9%), and percentage of particles 1-3 µm (35.9-37%). The CON produced a larger aerosol than BEN and BAN. The 2 BENs had similar airway delivery values that were greater than those for both CON and BAN.

CONCLUSIONS

Hypertonic saline aerosols generated with the BEN and BAN devices were similar, while that generated with the CON was different. Airway delivery was similar between the BEN devices, but higher than that observed with the BAN and CON devices.

Pain-induced changes in motor unit discharge depend on recruitment threshold and contraction speed

At high forces, the discharge rates of lower- and higher-threshold motor units (MU) are influenced in a different way by muscle pain. These differential effects may be particularly important for performing contractions at different speeds since the proportion of lower- and higher-threshold MUs recruited varies with contraction velocity. We investigated whether MU discharge and recruitment strategies are differentially affected by pain depending on their recruitment threshold (RT), across a range of contraction speeds. Participants performed ankle dorsiflexion sinusoidal-isometric contractions at two frequencies (0.25 and 1 Hz) and two modulation amplitudes [5% and 10% of the maximum voluntary contraction (MVC)] with a mean target torque of 20%MVC. High-density surface electromyography recordings from the tibialis anterior muscle were decomposed and the same MUs were tracked across painful (hypertonic saline injection) and nonpainful conditions. Torque variability, mean discharge rate (MDR), DR variability (DRvar), RT, and the delay between the cumulative spike train and the resultant torque output (neuromechanical delay, NMD) were assessed. The average RT was greater at faster contraction velocities (P = 0.01) but was not affected by pain. At the fastest contraction speed, torque variability and DRvar were reduced (P < 0.05) and MDR was maintained. Conversely, MDR decreased and DRvar and NMD increased significantly during pain at slow contraction speeds (P < 0.05). These results show that reductions in contraction amplitude and increased recruitment of higher-threshold MUs at fast contraction speeds appear to compensate for the inhibitory effect of nociceptive inputs on lower-threshold MUs, allowing the exertion of fast submaximal contractions during pain.NEW & NOTEWORTHY Pain induces changes in motor performance, motor unit recruitment, and rate coding behavior that varies across different contraction speeds. Here we show that that pain reduces motor unit discharge rate and prolongs the neuromechanical delay at slow contraction speeds only. This new evidence suggests that there are differential nociceptive inhibitory effects across the motor unit pool, which allows fast submaximal contractions to be exerted despite the presence of pain.

Effects of hypertonic saline on intracranial pressure and cerebral autoregulation in pediatric traumatic brain injury

OBJECTIVE

Hypertonic saline (HTS) is commonly used in children to lower intracranial pressure (ICP) after severe traumatic brain injury (sTBI). While ICP and cerebral perfusion pressure (CPP) correlate moderately to TBI outcome, indices of cerebrovascular autoregulation enhance the correlation of neuromonitoring data to neurological outcome. In this study, the authors sought to investigate the effect of HTS administration on ICP, CPP, and autoregulation in pediatric patients with sTBI.

METHODS

Twenty-eight pediatric patients with sTBI who were intubated and sedated were included. Blood pressure and ICP were actively managed according to the autoregulation index PRx (pressure relativity index to determine and maintain an optimal CPP [CPPopt]). In cases in which ICP was continuously > 20 mm Hg despite all other measures to decrease it, an infusion of 3% HTS was administered. The monitoring data of the first 6 hours after HTS administration were analyzed. The Glasgow Outcome Scale (GOS) score at the 3-month follow-up was used as the primary outcome measure, and patients were dichotomized into favorable (GOS score 4 or 5) and unfavorable (GOS score 1-3) groups.

RESULTS

The mean dose of HTS was 40 ml 3% NaCl. No significant difference in ICP and PRx was seen between groups at the HTS administration. ICP was lowered significantly in all children, with the effect lasting as long as 6 hours. The lowering of ICP was significantly greater and longer in children with a favorable outcome (p < 0.001); only this group showed significant improvement of autoregulatory capacity (p = 0.048). A newly established HTS response index clearly separated the outcome groups.

CONCLUSIONS

HTS significantly lowered ICP in all children after sTBI. This effect was significantly greater and longer-lasting in children with a favorable outcome. Moreover, HTS administration restored disturbed autoregulation only in the favorable outcome group. This highlights the role of a "rescuable" autoregulation regarding outcome, which might be a possible indicator of injury severity. The effect of HTS on autoregulation and other possible mechanisms should be further investigated.

Aerosolized Hypertonic Saline Hinders Biofilm Formation to Enhance Antibiotic Susceptibility of Multidrug-Resistant Acinetobacter baumannii

Limited therapeutic options are available for multidrug-resistant Acinetobacter baumannii (MDR-AB), and the development of effective treatments is urgently needed. The efficacy of four aerosolized antibiotics (gentamicin, amikacin, imipenem, and meropenem) on three different MDR-AB strains was evaluated using hypertonic saline (HS, 7 g/100 mL) as the aerosol carrier. HS aerosol effectively hindered biofilm formation by specific MDR-AB strains. It could also interrupt the swarming dynamics of MDR-AB and the production of extracellular polymeric substances, which are essential for biofilm progression. Biofilms protect the microorganisms from antibiotics. The use of HS aerosol as a carrier resulted in a decreased tolerance to gentamicin and amikacin in the biofilm-rich MDR-AB. Moreover, we tested the aerosol characteristics of antibiotics mixed with HS and saline, and results showed that HS enhanced the inhaled delivery dose with a smaller particle size distribution of the four antibiotics. Our findings demonstrate the potential of using “old” antibiotics with our “new” aerosol carrier, and potentiate an alternative therapeutic strategy to eliminate MDR-AB infections from a biofilm-disruption perspective.