Hemodynamic monitoring devices to predict fluid responsiveness in septic shock : a systematic review

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2021A monitorização hemodinâmica é um dos pilares da Medicina Intensiva que fornece informação útil sobre o estado do sistema cardiovascular do doente. A medição do débito cardíaco de um doente em choque permite a avaliação de outras variáveis importantes como a entrega de oxigénio e a perfusão tecidular. A abordagem inicial do doente em choque séptico consiste, entre outras atitudes, na ressuscitação hemodinâmica com bólus de fluídos. No entanto, nas fases seguintes do tratamento é necessário avaliar a necessidade de expansão de volume. O objetivo principal desta revisão narrativa é descrever os métodos de monitorização hemodinâmica utilizados atualmente e destacar as principais indicações e limitações de cada aparelho. A base de dados utilizada durante a pesquisa bibliográfica foi o Pubmed, tendo sido selecionados 73 artigos. Nesta revisão são mencionados vários métodos, incluindo o cateter arterial pulmonar, técnica de termodiluição transpulmonar, ecocardiograma, análise de contorno do pulso arterial, bioimpedância e bioreactância. A capacidade destes aparelhos determinarem a condição fluidorespondedora em doentes com choque séptico é discutida durante todo o trabalho. Os parâmetros dinâmicos, incluindo a variação da pressão de pulso e a variação do volume sistólico obtidos através da análise de contorno de pulso, são considerados bons preditores da condição fluidorespondedora. Pelo contrário, variáveis estáticas como a pressão venosa central podem ser utilizadas como indicadores da pré-carga, mas não preveem se o débito cardíaco vai aumentar em resposta a um bólus de fluídos. Os médicos devem conhecer os mecanismos básicos por detrás destes aparelhos, de modo a utilizá-los de forma correta, prevenindo assim possíveis consequências decorrentes da administração excessiva de fluidos. A criação de protocolos sobre métodos de monitorização pode contribuir para uniformizar a abordagem inicial.Hemodynamic monitoring is one of the cornerstones of Intensive Care that provides useful information regarding the patient’s cardiovascular state. Assessment of cardiac output in patients with septic shock allows the evaluation of other important variables like oxygen delivery and tissue perfusion. The initial approach in septic shock involves an initial hemodynamic resuscitation with fluid bolus, among other approaches. However, it’s necessary to evaluate the need for fluid expansion during the following phases of treatment. The main purpose of this narrative review is to describe the currently available hemodynamic monitoring devices and to point out the main indications and limitations of each device. The database used during the literary research was Pubmed, with 73 articles being included in this review. In this review are mentioned several methods, including the pulmonary artery catheter, transpulmonary thermodilution technique, arterial pulse contour analysis, echocardiogram, bioimpedance and bioreactance. The capacity of these devices in predetermining fluid responsiveness in patients with septic shock is discussed during the course of this review. Dynamic parameters, including pulse pressure variation and stroke volume variation obtained by pulse contour analysis, are considered good predictors of fluid responsiveness. On the contrary, static variables such as central venous pressure may be used as preload indicators, but cannot predict if cardiac output will increase in response to a fluid bolus. Clinicians should understand the basic mechanism in which these devices operate in order to correctly use them and prevent possible consequences of fluid overload. The creation of hemodynamic devices protocols could help standardize the initial monitoring approach in septic patients

Impact of diabetes mellitus on ventricular structure, arterial stiffness, and pulsatile hemodynamics in heart failure with preserved ejection fraction

Background-Heterogeneity in the underlying processes that contribute to heart failure with preserved ejection fraction (HFpEF) is increasingly recognized. Diabetes mellitus is a frequent comorbidity in HFpEF, but its impact on left ventricular and arterial structure and function in HFpEF is unknown. Methods and Results-Weassessed the impact of diabetesmellitus on left ventricular cellular and interstitial hypertrophy (assessedwith cardiacmagnetic resonance imaging, including T1mapping pregadolinium and postgadolinium administration), arterial stiffness (assessed with arterial tonometry), and pulsatile arterial hemodynamics (assessed with in-office pressure-flow analyses and 24-hour ambulatory monitoring) among 53 subjects with HFpEF (32 diabetic and 21 nondiabetic subjects). Despite few differences in clinical characteristics, diabetic subjects with HFpEF exhibited a markedly greater left ventricular mass index (78.1 [95% CI, 70.4-85.9] g versus 63.6 [95% CI, 55.8-71.3] g; P=0.0093) and indexed extracellular volume (23.6 [95% CI, 21.2-26.1] mL/m(2) versus 16.2 [95% CI, 13.1-19.4] mL/m(2); P=0.0008). Pronounced aortic stiffening was also observed in the diabetic group (carotid-femoral pulse wave velocity, 11.86 [95% CI, 10.4-13.1] m/s versus 8.8 [95% CI, 7.5-10.1] m/s; P=0.0027), with an adverse pulsatile hemodynamic profile characterized by increased oscillatory power (315 [95% CI, 258-373] mWversus 190 [95% CI, 144-236] mW; P=0.0007), aortic characteristic impedance (0.154 [95% CI, 0.124-0.183] mmHg/mL per second versus 0.096 [95% CI, 0.072-0.121] mm Hg/mL per second; P=0.0024), and forward (59.5 [95% CI, 52.8-66.1] mm Hg versus 40.1 [95% CI, 31.6-48.6] mm Hg; P=0.0010) and backward (19.6 [95% CI, 16.2-22.9] mm Hg versus 14.1 [95% CI, 10.9-17.3] mm Hg; P=0.0169) wave amplitude. Abnormal pulsatile hemodynamics were also evident in 24-hour ambulatory monitoring, despite the absence of significant differences in 24-hour systolic blood pressure between the groups. Conclusions-Diabetes mellitus is a key determinant of left ventricular remodeling, arterial stiffness, adverse pulsatile hemodynamics, and ventricular-arterial interactions in HFpEF

Conduit Artery Photoplethysmography and its Applications in the Assessment of Hemodynamic Condition

Elektroniskā versija nesatur pielikumusPromocijas darbā ir izstrādāta maģistrālo artēriju fotopletizmogrāfijas (APPG) metode hemodinamisko parametru novērtējumam. Pretstatot referentām metodēm, demonstrēta iespēja iegūt arteriālo elasticitāti raksturojošus parametrus, izmantojot APPG signāla formas analīzi (atvasinājuma un signāla formas aproksimācijas parametri) un ar APPG iegūtu pulsa izplatīšanās ātrumu unilaterālā gultnē. Izstrādāta APPG reģistrācijas standartizācija, mērījuma laikā nodrošinot optimālo sensora piespiedienu. Šis paņēmiens validēts ārējās ietekmes (sensora piespiediens) un hemodinamisko stāvokļu (perifērā vaskulārā pretestība) izmaiņās femorālā APPG signālā, identificējot būtiskākos faktorus APPG pielietojumos. Veikta APPG validācija asinsrites fizioloģijas un preklīniskā pētījumā demonstrējot APPG potenciālu pētniecībā un diagnostikā. Izstrādāts pulsa formas parametrizācijas paņēmiens, saistot fizioloģiskās un aproksimācijas modeļa komponentes. Atslēgas vārdi: maģistrālā artērija, fotopletizmogrāfija, arteriālā elasticitāte, metodes standartizācija, pulsa formas kvantifikācija, vazomocija, sepseThe doctoral thesis features the development of a conduit artery photoplethysmography technique (APPG) for the evaluation of hemodynamic parameters. Contrasting referent methods, the work demonstrates the possibility to receive parameters characterizing the arterial stiffness by means of APPG waveform analysis (derivation and waveform approximation parameters) and APPG obtained pulse wave velocity in a unilateral vascular bed. In this work APPG standardization technique was developed providing optimal probe contact pressure conditions. It was validated by altering the external factors (probe contact pressure) and hemodynamic conditions (peripheral vascular resistance) on the femoral APPG waveform identifying the key factors in APPG applications. The APPG validation in blood circulation physiology and a pre-clinical trial was performed demonstrating APPG potential in the extension of applications. An arterial waveform parameterization was developed relating the physiological wave to approximation model components. Keywords: conduit artery, photoplethysmography, arterial stiffness, method standardization, waveform parametrization, vasomotion, sepsi

Less invasive methods of advanced hemodynamic monitoring: principles, devices, and their role in the perioperative hemodynamic optimization.

The monitoring of the cardiac output (CO) and other hemodynamic parameters, traditionally performed with the thermodilution method via a pulmonary artery catheter (PAC), is now increasingly done with the aid of less invasive and much easier to use devices. When used within the context of a hemodynamic optimization protocol, they can positively influence the outcome in both surgical and non-surgical patient populations. While these monitoring tools have simplified the hemodynamic calculations, they are subject to limitations and can lead to erroneous results if not used properly. In this article we will review the commercially available minimally invasive CO monitoring devices, explore their technical characteristics and describe the limitations that should be taken into consideration when clinical decisions are made

A randomized controlled trial to assess the central hemodynamic response to exercise in patients with transient ischaemic attack and minor stroke

Early exercise engagement elicits meaningful changes in peripheral blood pressure in patients diagnosed with transient ischaemic attack (TIA) or minor stroke. However, central hemodynamic markers may provide clinicians with important diagnostic and prognostic information beyond that provided by peripheral blood pressure readings. The purpose of this single-centre, randomized, parallel-group clinical trial was to determine the effect of a 12-week aerobic exercise intervention on central and peripheral hemodynamic variables in patients with TIA or minor stroke. In this study, 47 participants (66±10 years) completed a baseline assessment, which involved the measurement of central and peripheral hemodynamic parameters, undertaken in the morning, in a fasted state. Participants were randomized to either a 12-week exercise or control group on completion of the baseline assessment. An identical follow-up assessment was completed post intervention. Central hemodynamic variables were assessed using an oscillometric device at both assessments. Analysis of covariance demonstrated a significant interaction for central and peripheral blood pressure and augmentation index (all P<0.05; ηp2.09–.11), with the exercise group presenting lower values than the control group post intervention (118±17 vs 132±28 mm Hg for central blood pressure; 125±19 vs 138±28 mm Hg for peripheral blood pressure; 104±49 vs 115±67% for augmentation index). The present study demonstrates that participation in an exercise program soon after stroke/TIA diagnosis may elicit significant beneficial changes to a patient's central systolic blood pressure and augmentation index. This may positively impact upon the treatment strategies implemented by clinicians in the care of patients with TIA and minor stroke

Haemodynamic patterns in children with primary hypertension — preliminary brief report

Wstęp Zakłada się, że początkowy okres nadciśnienia tętniczego pierwotnego (NTP) charakteryzuje się występowaniem krążenia hiperkinetycznego. Nie udowodniono jednak związku między wartościami ciśnienia tętniczego (począwszy od normotensji, aż do ciężkiego ambulatoryjnego nadciśnienia tętniczego) a zaburzeniami hemodynamicznymi u dzieci z NTP. Celem badania było scharakteryzowanie takich parametrów hemodynamicznych, jak wskaźnik sercowy (CI) i całkowity opor obwodowy (TPR) u dzieci z NTP w zależności od stadium nadciśnienia tętniczego. Materiał i metody Do badania włączono 95 pacjentów (15,3 ± 2 lata; 27 dziewczynek) skierowanych z powodu podwyższonych wartości ciśnienia tętniczego, u których wykluczono wtórne przyczyny nadciśnienia tętniczego. Prędkość fali tętna (PWV), CI i TPR były mierzone przy użyciu funkcji oscylometrycznej analizy fali tętna aparatu Vicorder. Klasyfikacja ciśnienia tętniczego była określana zgodnie z obecnymi wytycznymi na podstawie całodobowego ambulatoryjnego pomiaru ciśnienia tętniczego (ABPM). Wyniki Pełnemu procesowi diagnostycznemu zostało poddanych 95 pacjentów z podwyższonym ciśnieniem tętniczym. W jego wyniku u 31 pacjentów stwierdzono normotensję, u 14 stan przednadciśnieniowy, u 7 ambulatoryjne nadciśnienie tętnicze, u 43 ciężkie ambulatoryjne nadciśnienie tętnicze. Porównanie średnich wartości CI dla poszczególnych grup wykazało znaczący wzrost CI powiązany z kategorią nadciśnienia tętniczego. Wzrostowi CI towarzyszył nieistotny statystycznie spadek TPR. Wartości CI korelowały ze średnim ciśnieniem tętniczym, częstością rytmu serca, szybkością fali tętna i ładunkiem ciśnienia skurczowego. Wartości TPR korelowały z parametrami antropometrycznymi, w tym ujemnie z obwodem talii, średnim ciśnieniem tętniczym i szybkością fali tętna. Analiza regresji krokowej nie wykazała predyktorów CI, natomiast dla TPR predyktorem okazał się obwód talii (Beta –0,310; p = 0,021). Wnioski U dzieci z pierwotnym nadciśnieniem tętniczym stwierdzono zaburzenia hemodynamiczne o cechach krążenia hiperkinetycznego narastające wraz ze wzrostem stadium nadciśnienia tętniczego. Wzrostowi CI towarzyszył jednak jedynie statystycznie nieistotny spadek TPRI. Ten rodzaj zaburzeń hemodynamicznych tłumaczy mechanizm wzrostu ciśnienia tętniczego u dzieci z NTP. Otyłość trzewna wyrażona jako obwód talii ma znaczenie w mechanizmie rozwoju krążenia hiperkinetycznego.Background It is assumed that the initial phase of primary hypertension (PH) is characterized by the presence of hyperkinetic circulation. However, the relationship between blood pressure status (from normal blood pressure to severe ambulatory hypertension) and haemodynamic patterns in children with PH were not described. The objective of this study was to characterize the haemodynamic parameters such as cardiac index (CI) and a total peripheral resistance index (TPR) in children with PH depending on the stage of hypertension. Materials and methods The study included 95 patients (15.3 ± 2.0 years; 27 girls) referred due to the elevated blood pressure, in whom secondary hypertension was excluded. Pulse wave velocity (PWV), CI and TPRI were assessed indirectly using Vicorder device. PH was diagnosed according to the European Society of Hypertension paediatric guidelines and confirmed by 24-hour ambulatory BP monitoring (ABPM). Results Of 95 patients, 31 had normal blood pressure, 14 prehypertension, 7 ambulatory hypertension and 43 severe ambulatory hypertension. Comparison of the mean values of cardiac index (CI) for each group showed significant increase in CI linked to the category of hypertension. CI increase was accompanied by a non-significant decrease of TPR. Mean CI values correlated with 24-hour mean arterial pressure, 24-hour heart rate, PWV-SDS and systolic blood pressure load. Mean TPR values correlated with anthropometrical parameters, including negative correlation with waist circumference and positive with 24- hour mean arterial pressure and negative with pulse wave velocity. Stepwise regression analysis showed no predictors for CI, but for TPR the only predictor was waist circumference Conclusions Children with PH are characterized by haemodynamic patterns typical of hyperkinetic circulation increasing with increasing stage of hypertension. Non-significant decrease in TPR in children with increased CI explains haemodynamic basis of elevation of blood pressure. Visceral Obesity expressed as a waist circumference seems to play role in the mechanism of the development of hyperkinetic circulation