Comment: Balanced Salt Solutions for Critically Ill Patients: Nonplused and Back to Basics.

The analysis of trial results of the intravenous fluids pharmacodynamics revealed problems common to all studies, such as varying study designs, clinical discretion for treatments, and heterogeneous patients. We believe that in the methodology of future research it is also necessary to pay due attention to the actual rather than theoretical physicochemical parameters of the solutions used, such as osmolality, pH, and potential excess of bases. Paying attention to these parameters of intravenous fluids will be useful for assessing their role in producing pharmacodynamic effects in critically ill patients.

Dynamics of Local Temperature in the Fingertips After the Cuff Occlusion Test: Infrared Diagnosis of Adaptation Reserves to Hypoxia and Assessment of Survivability of Victims at Massive Blood Loss.

Background: Since changes in the tone and size of the lumen of peripheral blood vessels with massive blood loss are part of the mechanism of adaptation to hypoxia, which automatically changes the flow of warm blood to the fingertips, it was assumed that infrared thermography of the fingertips can reveal the dynamics of heat release in them, reflecting the reactivity of peripheral blood vessels and adaptation to hypoxia. It was assumed that the cuff occlusion test (COT) would assess the available reserves of adaptation to hypoxia and improve the accuracy of resistance to hypoxia and the prognosis of survival in massive blood loss. Methods: The temperature change in the fingertips before and after the application of COT in the corresponding hand was studied in healthy adult volunteers, donors after donating 400 mL of blood and in victims with blood loss of less than or more than 35%. Results: During COT, the temperature in the fingers of the ischemic hand decreased in all the subjects. After COT the temperature in the fingers rose above the baseline level in healthy volunteers and in donors who donated 400 mL of blood, but did not increase in most patients with massive blood loss, of which some patients died despite the treatment. Conclusions: We report the dynamics of local temperature in the finger pads after the COT in healthy adult volunteers, in donors after they donated 400 mL of venous blood each, and in victims with massive blood loss less than or greater than 35%. It is shown that the detection of local hyperthermia in the finger pads after occlusion is a sign of good adaptation to hypoxia and the probability of survivability of the victim with massive blood loss.

Using Ultrasonography to Determine Optimal Head-down Tilt Position Angle in Patients before Catheterization of the Internal Jugular Vein.

CONTEXT: It is believed that 15°-25° head-down tilt position increases the internal jugular vein cross-sectional area (IJV CSA). The increase in IJV CSA before puncture reduces the risk of its perforation. This pattern was not observed in all patients. We assumed that the absence of respiratory-based IJV excursion is one of the criteria of head-down tilt position effectiveness. AIMS: The aim of this study is to determine the head-down tilt angle, which ensures the absence of the respiratory-based IJV excursion. SUBJECTS AND METHODS: Prospective study included twenty adult patients. The IJVs scanning was carried out in 1 min after placing the patients in a horizontal position on their back and in 1 min after placing them in the head-down tilt position at 5°, 10°, 15°, and 20° tilt angles. RESULTS: We found that collapsibility index of <9% indicating the absence of respiratory-based IJV excursion was recorded in 25% of patients in the horizontal supine position. In this case, placing the patients in the Trendelenburg position for IJV catheterization may not be indicated. In 65% of the patients, the respiratory-based excursion was not observed at 10° head-down tilt position. Only 35% of the patients required 15° head-down tilt position. CONCLUSIONS: In clinical settings, the disappearance of respiratory-based vein excursion on the ultrasound scanner screen can be considered as criteria of the head-down tilt position effectiveness.

The dynamics of changing internal jugular veins diameter based on increasing head elevation angle.

CONTEXT: Venous outflow from the cranial cavity occurs mainly through the internal jugular vein (IJV). The increase in venous outflow through IJV is possible by head elevation. IJV collapse may indicate the reduction of blood volume in the vein and show the head elevation effectiveness. AIMS: The aim of this study is to examine the impact of head elevation on IJV size. SUBJECTS AND METHODS: IJV ultrasound scanning in 31 healthy volunteers was carried after gradual head elevation at 15°, 30°, and 45°. Maximum and minimum IJV diameters were recorded. Mean ± standard deviation, median, range, and collapsibility index were calculated. RESULTS: Thirty-one volunteers were involved (19 males), their average age was 37.0 ± 11.5 years. Increasing the head elevation angle by 15°, 30° and 45° resulted in a decrease in IJV diameter in the right and left sides in all patients. The occurrence of the vein walls collapse corresponds to the collapsibility index equal to 100%. The results showed that 100% collapsibility index was recorded in 6 patients (19%) at 15° head elevation, in 12 patients (39%) at 30°, in 11 patients (35%) at 45°. In two volunteers (6%), 100% collapsibility index was not recorded even at maximum 45° head elevation. CONCLUSIONS: Ultrasound IJV scanning during gradual head elevation together with the collapsibility index calculation could be useful guidance for the venous outflow assessment. In order to prove and extend the study findings, more research is needed.

Effect of hydrogen peroxide on erythrocyte temperature in vitro.

Hydrogen peroxide (H2O2) is produced by most human cells. Cellular enzymes determine the features of the chemico-biological interaction between cells and hydrogen peroxide. The catalase is main intracellular enzyme that inactivates H2O2 in cells, in particular, erythrocytes. Catalase decomposes hydrogen peroxide into water and oxygen with the release of energy. However, until now, there is no convincing scientific data proving that the temperature of the cells changes when adding a solution of hydrogen peroxide. We conducted studies on how H2O2 solutions with different concentrations affect the change in erythrocytes temperature in vitro. Our results proved that toxic doses of hydrogen peroxide increase the temperature of red blood cells.

Ultrasound-guided internal jugular vein cannulation in the obese patient in a forced semi-sitting position.

INTRODUCTION: Central venous cannulation may be difficult in morbidly obese patients. We present a case of successful right internal jugular vein catheterization under real-time ultrasound guidance in an obese patient in a forced semi-sitting position. CASE REPORT: A 43-year-old male patient with body mass of 182 kg (body mass index, 52.2 kg/m2) was admitted to the clinic 48 h after the trauma. The patient was in a forced semi-sitting position (37° head elevation). The patient was not able to perform the Valsalva maneuver. In the reported case, the lateral access for right internal jugular vein catheterization was chosen. We selected a lateral-oblique probe position for the ultrasound-guided internal jugular vein cannulation. Internal jugular vein catheterization was successful at the first attempt. CONCLUSION: Ultrasound imaging enables us to choose a desirable access for successful internal jugular vein cannulation in the obese patient without head-down tilt position. The lateral-oblique probe position for internal jugular vein cannulation may have advantages in certain clinical situations.

Changes in the Internal Size of the Jugular Vein in Adult Patients with Hypovolemia.

The present study is aimed at establishing the values of internal jugular vein (IJV) anterior-posterior and medial-lateral sizes in patients with hypovolemia. A total of 25 adult Intensive Care Unit patients with hypovolemia were studied. It was found that the anterior-posterior vein size in patients with hypovolemia was significantly less than medial-lateral size during inhalation and during exhalation as well (P < 0.05). Besides, the value of the anterior-posterior size (Dmin) <7 mm was recorded in 20 from 25 patients (80%). At the same time, the medial-lateral size (Dmin) <7 mm was recorded only in six patients (24%). In patients with hypovolemia, the medial-lateral diameter of IJV is more than its anterior-posterior diameter. These data might be useful for justifying the benefits of using lateral access for IJV catheterization under ultrasound imaging in patients with hypovolemia.

Continuous Positive Airway Pressure Prevents Hypoxia in Dental Patient with Obstructive Sleep Apnea Syndrome under Intravenous Sedation.

Use of sedation in patients with obstructive sleep apnea (OSA) in dentistry is limited. Hypoxia may develop during medication sleep in dental patients with OSA because of repetitive partial or complete obstruction of the upper airway. In this regard, anesthesiologists prefer not to give any sedative to surgical patients with OSA or support the use of general anesthesia due to good airway control. We report a case where we could successfully sedate a dental patient with OSA using intraoperative continuous positive airway pressure (CPAP) without hypoxia. Use of sedation and intraoperative CPAP in patients with OSA may be considered only if the effectiveness at home CPAP therapy is proven.

Management of exaggerated gag reflex in dental patients using intravenous sedation with dexmedetomidine.

Pharmacological sedation is one of the effective ways of prevention of gag reflex development in patients experiencing anxiety and fright before dental treatment. We are reporting a case where we could successfully eliminate exaggerated gag reflex (intravenous [IV] Gagging Severity Index) in a dental patient using IV sedation with dexmedetomidine. IV administration of dexmedetomidine provided elimination of gag reflex at a depth of sedation for the patient with the Richmond Agitation-Sedation Scale score of -2 and -1. The patient received dexmedetomidine 1.0 µg/kg for 10 min and then a continuous infusion of dexmedetomidine 0.4 µg/kg/h. The use of dexmedetomidine for sedation may be an alternative to other pharmacological agents in patients with dental anxiety accompanied by exaggerated gag reflex.