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Clinical Microbiology and Infection :... Feb 2020Bloodstream infections (BSIs) are a major cause of morbidity and mortality in paediatric patients. For fast and accurate diagnosis, blood culture (BC) is the reference... (Review)
Review
BACKGROUND
Bloodstream infections (BSIs) are a major cause of morbidity and mortality in paediatric patients. For fast and accurate diagnosis, blood culture (BC) is the reference standard. However, the procedure for blood sampling in paediatric patients, particularly the optimal blood volume, is the subject of controversy stemming from a lack of knowledge of the bacterial load and because of several obstacles such as low intravascular volume and the risk of causing anaemia.
AIMS
The aim of this narrative review is to summarize current knowledge on blood sampling in paediatric patients for BC purposes, in particular blood volume and number and type of BC bottles needed for reasonable future guidelines/recommendations.
SOURCES
A comprehensive literature search of PubMed, including all publications in English, was performed in June 2019 using the search terms 'blood culture', 'blood volume', 'bloodstream infection', 'diagnostic', 'paediatric' and/or 'sepsis'.
CONTENT
The amount of inoculated blood determines the sensitivity, specificity and time to positivity of a BC, and low-level bacteraemia (≤10 cfu/mL) in paediatric patients is presumed to be more common than reported. Current approaches for 'adequate' blood volume for paediatric BC are mainly weight- or age-dependent. Of these recommendations, the scheme devised by Gaur and colleagues seems most appropriate and calls for a sample of 1-1.5 mL for children weighing <11 kg and 7.5 mL for a patient weight of 11-17 kg to be drawn into one BC bottle. Inclusion of a more detailed grading in the weight range 4-14 kg, as published by Gonsalves and colleagues, might be useful.
IMPLICATIONS
This review could be important for future guidelines on paediatric BC collection and thus could contribute to improving patient management and lowering the economic and global health burden associated with BSI. Furthermore, upcoming molecular-based approaches with low sample volumes might be an interesting alternative.
Topics: Bacteremia; Bacterial Load; Blood Culture; Blood Volume; Child; Clinical Trials as Topic; Cross-Sectional Studies; Humans; Infant, Newborn; Pediatrics; Sensitivity and Specificity; Time Factors
PubMed: 31654793
DOI: 10.1016/j.cmi.2019.10.006 -
Blood Purification 2020Intradialytic hypotension (IDH) occurs in approximately 10-12% of treatments. Whereas several definitions for IDH are available, a nadir systolic blood pressure carries... (Review)
Review
Intradialytic hypotension (IDH) occurs in approximately 10-12% of treatments. Whereas several definitions for IDH are available, a nadir systolic blood pressure carries the strongest relation with outcome. Whereas the relation between IDH may partly be based on patient characteristics, it is likely that also impaired organ perfusion leading to permanent damage, plays a role in this relationship. The pathogenesis of IDH is multifactorial and is based on a combination of a decline in blood volume (BV) and impaired vascular resistance at a background of a reduced cardiovascular reserve. Measurements of absolute BV based on an on-line dilution method appear more promising than relative BV measurements in the prediction of IDH. Also, feedback treatments in which ultrafiltration rate is automatically adjusted based on changes in relative BV have not yet resulted in improvement. Frequent assessment of dry weight, attempting to reduce interdialytic weight gain and prescribing more frequent or longer dialysis treatments may aid in preventing IDH. The impaired vascular response can be improved using isothermic or cool dialysis treatment which has also been associated with a reduction in end organ damage, although their effect on mortality has not yet been assessed. For the future, identification of vulnerable patients based on artificial intelligence and on-line assessment of markers of organ perfusion may aid in individualizing treatment prescription, which will always remain dependent on the clinical context of the patient.
Topics: Blood Pressure; Blood Volume; Humans; Hypotension; Renal Dialysis; Vascular Resistance
PubMed: 31851975
DOI: 10.1159/000503776 -
Colombia Medica (Cali, Colombia) Dec 2020Damage control resuscitation should be initiated as soon as possible after a trauma event to avoid metabolic decompensation and high mortality rates. The aim of this... (Review)
Review
Damage control resuscitation should be initiated as soon as possible after a trauma event to avoid metabolic decompensation and high mortality rates. The aim of this article is to assess the position of the Trauma and Emergency Surgery Group (CTE) from Cali, Colombia regarding prehospital care, and to present our experience in the implementation of the "Stop the Bleed" initiative within Latin America. Prehospital care is phase 0 of damage control resuscitation. Prehospital damage control must follow the guidelines proposed by the "Stop the Bleed" initiative. We identified that prehospital personnel have a better perception of hemostatic techniques such as tourniquet use than the hospital providers. The use of tourniquets is recommended as a measure to control bleeding. Fluid management should be initiated using low volume crystalloids, ideally 250 cc boluses, maintaining the principle of permissive hypotension with a systolic blood pressure range between 80- and 90-mm Hg. Hypothermia must be management using warmed blankets or the administration of intravenous fluids warmed prior to infusion. However, these prehospital measures should not delay the transfer time of a patient from the scene to the hospital. To conclude, prehospital damage control measures are the first steps in the control of bleeding and the initiation of hemostatic resuscitation in the traumatically injured patient. Early interventions without increasing the transfer time to a hospital are the keys to increase survival rate of severe trauma patients.
Topics: Algorithms; Blood Volume; Body Temperature; Emergency Medical Services; Hemorrhage; Humans; Injury Severity Score; Resuscitation; Wounds and Injuries
PubMed: 33795898
DOI: 10.25100/cm.v51i4.4486 -
Seminars in Perinatology Apr 2020Pharmacologic interventions play a major role in obstetrical care throughout pregnancy, labor and delivery and the postpartum. Traditionally, obstetrical providers have... (Review)
Review
Pharmacologic interventions play a major role in obstetrical care throughout pregnancy, labor and delivery and the postpartum. Traditionally, obstetrical providers have utilized standard dosing regimens developed for non-obstetrical indications based on pharmacokinetic knowledge from studies in men or non-pregnant women. With the recognition of pregnancy as a special pharmacokinetic population in the late 1990s, investigators have begun to study drug disposition in this unique patient dyad. Many of the basic physiologic changes that occur during pregnancy have significant impact on drug absorption, distribution and clearance. Activity of Phase I and Phase II drug metabolizing enzymes are differentially altered by pregnancy, resulting in drug concentrations sufficiently different for some medications that efficacy or toxicity is affected. Placental transporters play a major dynamic role in determining fetal drug exposure. In the past two decades, we have begun to expand our understanding of obstetrical pharmacology; however, to truly optimize pharmacologic care of our pregnant patients and their developing fetus, additional research is critically needed.
Topics: ATP-Binding Cassette Transporters; Absorption, Physiological; Cardiac Output; Cytochrome P-450 Enzyme System; Drug Elimination Routes; Female; Glomerular Filtration Rate; Humans; Maternal-Fetal Exchange; Multidrug Resistance-Associated Proteins; Organic Cation Transport Proteins; Pharmaceutical Preparations; Pharmacokinetics; Placenta; Plasma Volume; Pregnancy; Tissue Distribution
PubMed: 32115202
DOI: 10.1016/j.semperi.2020.151221 -
Journal of the American College of... Mar 2021Investigators have hypothesized that sodium-glucose cotransporter 2 (SGLT2) inhibitors exert diuretic effects that contribute to their ability to reduce serious heart... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Investigators have hypothesized that sodium-glucose cotransporter 2 (SGLT2) inhibitors exert diuretic effects that contribute to their ability to reduce serious heart failure events, and this action is particularly important in patients with fluid retention.
OBJECTIVES
This study sought to evaluate the effects of the SGLT2 inhibitor empagliflozin on symptoms, health status, and major heart failure outcomes in patients with and without recent volume overload.
METHODS
This double-blind randomized trial compared the effects of empagliflozin and placebo in 3,730 patients with heart failure and a reduced ejection fraction, with or without diabetes. Approximately 40% of the patients had volume overload in the 4 weeks before study enrollment.
RESULTS
Patients with recent volume overload were more likely to have been hospitalized for heart failure and to have received an intravenous diuretic agent in an outpatient setting in the previous 12 months, and to experience a heart failure event following randomization, even though they were more likely to be treated with high doses of a loop diuretic agent as an outpatient (all p < 0.001). When compared with placebo, empagliflozin reduced the composite risk of cardiovascular death or hospitalization for heart failure, decreased total hospitalizations for heart failure, and improved health status and functional class. Yet despite the predisposition of patients with recent volume overload to fluid retention, the magnitude of these benefits (even after 1 month of treatment) was not more marked in patients with recent volume overload (interaction p values > 0.05). Changes in body weight, hematocrit, and natriuretic peptides (each potentially indicative of a diuretic action of SGLT2 inhibitors) did not track each other closely in their time course or in individual patients.
CONCLUSIONS
Taken together, study findings do not support a dominant role of diuresis in mediating the physiological changes or clinical benefits of SGLT2 inhibitors on the course of heart failure in patients with a reduced ejection fraction. (EMPagliflozin outcomE tRial in Patients With chrOnic heaRt Failure With Reduced Ejection Fraction [EMPEROR-Reduced]; NCT03057977).
Topics: Aged; Benzhydryl Compounds; Blood Volume; Diabetes Mellitus, Type 2; Diuretics; Drug Synergism; Female; Glomerular Filtration Rate; Glucosides; Heart Failure; Hematocrit; Humans; Male; Natriuretic Peptides; Outcome Assessment, Health Care; Sodium Potassium Chloride Symporter Inhibitors; Sodium-Glucose Transporter 2 Inhibitors; Stroke Volume; Water-Electrolyte Imbalance
PubMed: 33736819
DOI: 10.1016/j.jacc.2021.01.033 -
Critical Care (London, England) Apr 2023In patients on mechanical ventilation, positive end-expiratory pressure (PEEP) can decrease cardiac output through a decrease in cardiac preload and/or an increase in... (Clinical Trial)
Clinical Trial
BACKGROUND
In patients on mechanical ventilation, positive end-expiratory pressure (PEEP) can decrease cardiac output through a decrease in cardiac preload and/or an increase in right ventricular afterload. Increase in central blood volume by fluid administration or passive leg raising (PLR) may reverse these phenomena through an increase in cardiac preload and/or a reopening of closed lung microvessels. We hypothesized that a transient decrease in PEEP (PEEP-test) may be used as a test to detect volume responsiveness.
METHODS
Mechanically ventilated patients with PEEP ≥ 10 cmHO ("high level") and without spontaneous breathing were prospectively included. Volume responsiveness was assessed by a positive PLR-test, defined as an increase in pulse-contour-derived cardiac index (CI) during PLR ≥ 10%. The PEEP-test consisted in reducing PEEP from the high level to 5 cmHO for one minute. Pulse-contour-derived CI (PiCCO2) was monitored during PLR and the PEEP-test.
RESULTS
We enrolled 64 patients among whom 31 were volume responsive. The median increase in CI during PLR was 14% (11-16%). The median PEEP at baseline was 12 (10-15) cmHO and the PEEP-test resulted in a median decrease in PEEP of 7 (5-10) cmHO, without difference between volume responsive and unresponsive patients. Among volume responsive patients, the PEEP-test induced a significant increase in CI of 16% (12-20%) (from 2.4 ± 0.7 to 2.9 ± 0.9 L/min/m, p < 0.0001) in comparison with volume unresponsive patients. In volume unresponsive patients, PLR and the PEEP-test increased CI by 2% (1-5%) and 6% (3-8%), respectively. Volume responsiveness was predicted by an increase in CI > 8.6% during the PEEP-test with a sensitivity of 96.8% (95% confidence interval (95%CI): 83.3-99.9%) and a specificity of 84.9% (95%CI 68.1-94.9%). The area under the receiver operating characteristic curve of the PEEP-test for detecting volume responsiveness was 0.94 (95%CI 0.85-0.98) (p < 0.0001 vs. 0.5). Spearman's correlation coefficient between the changes in CI induced by PLR and the PEEP-test was 0.76 (95%CI 0.63-0.85, p < 0.0001).
CONCLUSIONS
A CI increase > 8.6% during a PEEP-test, which consists in reducing PEEP to 5 cmHO, reliably detects volume responsiveness in mechanically ventilated patients with a PEEP ≥ 10 cmHO. Trial registration ClinicalTrial.gov (NCT 04,023,786). Registered July 18, 2019. Ethics Committee approval CPP Est III (N° 2018-A01599-46).
Topics: Humans; Blood Volume; Cardiac Output; Diagnostic Techniques, Cardiovascular; Diagnostic Techniques, Respiratory System; Fluid Therapy; Heart; Hemodynamics; Positive-Pressure Respiration; Respiration, Artificial; ROC Curve
PubMed: 37031182
DOI: 10.1186/s13054-023-04424-7 -
Current Hypertension Reports May 2022The regulation of blood pressure is conventionally conceptualised into the product of "circulating blood volume" and "vasoconstriction components". Over the last few... (Review)
Review
PURPOSE OF REVIEW
The regulation of blood pressure is conventionally conceptualised into the product of "circulating blood volume" and "vasoconstriction components". Over the last few years, however, demonstration of tissue sodium storage challenged this dichotomous view.
RECENT FINDINGS
We review the available evidence pertaining to this phenomenon and the early association made with blood pressure; we discuss open questions regarding its originally proposed hypertonic nature, recently challenged by the suggestion of a systemic, isotonic, water paralleled accumulation that mirrors absolute or relative extracellular volume expansion; we present the established and speculate on the putative implications of this extravascular sodium excess, in either volume-associated or -independent form, on blood pressure regulation; finally, we highlight the prevalence of high tissue sodium in cardiovascular, metabolic and inflammatory conditions other than hypertension. We conclude on approaches to reduce sodium excess and on the potential of emerging imaging technologies in hypertension and other conditions.
Topics: Blood Pressure; Blood Volume; Humans; Hypertension; Sodium; Vasoconstriction
PubMed: 35192140
DOI: 10.1007/s11906-022-01180-x