Accuracy of Mean Value of Central Venous Pressure from Monitor Digital Display: Influence of Amplitude of Central Venous Pressure during Respiration / 中国医学科学杂志(英文版)

Background A simple measurement of central venous pressure (CVP)-mean by the digital monitor display has become increasingly popular. However, the agreement between CVP-mean and CVP-end (a standard method of CVP measurement by analyzing the waveform at end-expiration) is not well determined. This study was designed to identify the relationship between CVP-mean and CVP-end in critically ill patients and to introduce a new parameter of CVP amplitude (ΔCVP= CVPmax - CVPmin) during the respiratory period to identify the agreement/disagreement between CVP-mean and CVP-end.Methods In total, 291 patients were included in the study. CVP-mean and CVP-end were obtained simultaneously from each patient. CVP measurement difference (|CVP-mean - CVP-end|) was defined as the difference between CVP-mean and CVP-end. The ΔCVP was calculated as the difference between the peak (CVPmax) and the nadir value (CVPmin) during the respiratory cycle, which was automatically recorded on the monitor screen. Subjects with |CVP-mean - CVP-end|≥ 2 mmHg were divided into the inconsistent group, while subjects with |CVP-mean - CVP-end| < 2 mmHg were divided into the consistent group.Results ΔCVP was significantly higher in the inconsistent group [7.17(2.77) vs.5.24(2.18), P<0.001] than that in the consistent group. There was a significantly positive relationship between ΔCVP and |CVP-mean - CVP-end| (r=0.283, P <0.0001). Bland-Altman plot showed the bias was -0.61 mmHg with a wide 95% limit of agreement (-3.34, 2.10) of CVP-end and CVP-mean. The area under the receiver operating characteristic curves (AUC) of ΔCVP for predicting |CVP-mean - CVP-end| ≥ 2 mmHg was 0.709. With a high diagnostic specificity, using ΔCVP<3 to detect |CVP-mean - CVP-end| lower than 2mmHg (consistent measurement) resulted in a sensitivity of 22.37% and a specificity of 93.06%. Using ΔCVP>8 to detect |CVP-mean - CVP-end| >8 mmHg (inconsistent measurement) resulted in a sensitivity of 31.94% and a specificity of 91.32%.Conclusions CVP-end and CVP-mean have statistical discrepancies in specific clinical scenarios. ΔCVP during the respiratory period is related to the variation of the two CVP methods. A high ΔCVP indicates a poor agreement between these two methods, whereas a low ΔCVP indicates a good agreement between these two methods.

Comparison of vena cava distensibility index and pulse pressure variation for the evaluation of intravascular volume in critically ill children

Abstract Objective: In this study, the authors aimed to evaluate the effectiveness of the vena cava distensibility index and pulse pressure variation as dynamic parameters for estimating intravascular volume in critically ill children. Methods: Patients aged 1 month to 18 years, who were hospitalized in the present study's pediatric intensive care unit, were included in the study. The patients were divided into two groups according to central venous pressure: hypovolemic (< 8mmHg) and non-hypovolemic (central venous pressure ≥ 8 mmHg) groups. In both groups, vena cava distensibility index was measured using bedside ultrasound and pulse pressure variation. Measurements were recorded and evaluated under arterial monitoring. Results: In total, 19 (47.5%) of the 40 subjects included in the study were assigned to the central venous pressure ≥ 8 mmHg group, and 21 (52.5%) to the central venous pressure < 8 mmHg group. A moderate positive correlation was found between pulse pressure variation and vena cava distensibility index (r = 0.475, p < 0.01), while there were strong negative correlations of central venous pressure with pulse pressure variation and vena cava distensibility index (r = -0.628, p < 0.001 and r = -0.760, p < 0.001, respectively). In terms of predicting hypovolemia, the predictive power for vena cava distensibility index was > 16% (sensitivity, 90.5%; specificity, 94.7%) and that for pulse pressure variation was > 14% (sensitivity, 71.4%; specificity, 89.5%). Conclusion: Vena cava distensibility index has higher sensitivity and specificity than pulse pressure variation for estimating intravascular volume, along with the advantage of non-invasive bedside application.

Enfermedad hepática congestiva, las repercusiones hepáticas de un corazón enfermo / Congestive liver disease, the hepatic consequences of a diseased heart

La hepatopatía congestiva comprende el espectro de manifestaciones a nivel del hígado, con injuria inducida como consecuencia de la congestión venosa hepática por una alteración en el flujo venoso del tracto de salida hepático. La etiología más frecuente es la falla cardiaca derecha, que por aumento de la presión venosa central, lleva retrógradamente al aumento de la presión venosa hepática, disminución del flujo hepático y disminución de la saturación de oxígeno, con congestión a nivel sinusoidal y particular compromiso de los hepatocitos de la zona 3. Generalmente tiene una presentación subclínica en cuanto a manifestaciones hepáticas que son enmascaradas por los signos y síntomas de falla cardiaca. El diagnóstico comprende la suma de hallazgos serológicos, imagenológicos e histológicos, luego de una exclusión de otras patologías con posible injuria hepática. El tratamiento se basa en el manejo de la falla cardiaca de base, y el pronóstico a su vez, queda supeditado a la fase de la enfermedad cardiaca de base. Se realizó una búsqueda de la literatura con el fin de construir una revisión de esta entidad, con conceptos actualizados a partir de la evidencia reciente.

Congestive liver disease comprises the spectrum of manifestations secondary to liver injury as a consequence of hepatic venous congestion due to a disturbance in the hepatic venous outflow. The most frequent cause is right heart failure, which, due to an increase in central venous pressure, leads retrogradely to an increase in hepatic venous pressure, a decrease in liver inflow and a decrease in oxygen saturation, with sinusoidal congestion and characteristic compromise of zone 3 hepatocytes. Its presentation is usually subclinical in terms of liver manifestations, masked by the signs and symptoms of heart failure. The diagnosis includes the sum of serological, imaging and histological findings, after exclusion of other entities involving liver injury. Treatment is based on the management of the underlying heart failure and the prognosis is as well dependent on the stage of the underlying heart disease. A literature search was carried out in order to create a review of this entity with updated concepts based on recent evidence.

Pressão arterial central e risco cardiovascular / Central blood pressure and cardiovascular risk

Pressão Central, como o nome indica, é uma medida hemodinâmica semelhante a pressão arterial convencional porém avaliada de forma indireta por equipamento especifico, que avalia estes parâmetros na saída do sangue na raiz da aorta. Esta medida tem uma maior confiabilidade pois prediz de forma mais acurada os riscos de adoecimento e morte cardiovascular. Isto ocorre, pois a a onda de pulso (OP) ao percorrer os trajetos arteriais sofrem ampliações e importantes modificações no seu contorno deformando o valor original. Embora seja mais precisa em valores, ainda não é usado de rotina na pratica clinica por razoes de custos dos seus equipamentos e provavelmente por exigir habilidades maiores que as medidas captadas pelo equipamentos de mensuração periférica

Central pressure, as the name implies, is a hemodynamic measure similar to conventional blood pressure, but indirectly assessed by specific equipment, which evaluates these parameters at the blood outlet at the root of the aorta. This measure has greater confidence because it more accurately predicts the risks of cardiovascular disease and death. This occurs because the pulse wave (OP) when traversing the arterial paths provides enlargements and modifications in its contour, deforming the original value. Although it is more precise in terms of values, it is not yet routinely used in clinical practice for reasons of the cost of its equipment and probably because it requires greater needs than measures captured by peripheral measurement equipment

Caudal vena cava collapsibility index in healthy cats by ultrasonography / [Índice de colapsibilidade da veia cava caudal em gatos domésticos Saudáveis, obtido por meio de ultrassonografia]

The objective of this study was to calculate the collapsibility index (CI) in a group of 15 healthy adult mixed breed cats via right hepatic intercostal ultrasound view. The minimal and the maximal diameters of the caudal vena cava (CVC) were obtained during inspiration and expiration, respectively, then CI was calculated. The mean diameter of the CVC was 0.5cm. The mean CI was 28±3% and CI was not significantly associated with gender. As in human medicine, there is a growing need for less invasive monitoring in small animal practice. The CI enables the assessment of estimated volemia without the need for a central venous catheter. This is the first reported study investigating CI in cats.(AU)

O objetivo deste estudo foi calcular o índice de colapsabilidade (IC) em um grupo de 15 gatos adultos, saudáveis e SRD, por meio da janela ultrassonográfica hepática intercostal direita. Os diâmetros mínimo e máximo da veia cava caudal (VCC) foram obtidos durante a inspiração e a expiração, respectivamente. O IC foi calculado, posteriormente. O diâmetro médio da VCC foi de 0,5cm. O diâmetro médio do IC foi de 28±3%, e o IC não foi significativamente associado ao gênero. Como na medicina humana, há uma necessidade crescente de monitoramento menos invasivo na prática de pequenos animais. O IC possibilita a avaliação da volemia estimada sem a necessidade de um cateter venoso central. Este é o primeiro estudo relatado sobre IC em gatos domésticos.(AU)

Effect of opium addiction on postoperative arrhythmia among patients undergoing cabg operation on cardiopulmonary bypass

Abstract Objectives: Postoperative arrhythmia is an important complication of coronary artery bypass grafting (CABG) surgeries among patients. It seems that opioid usage is implicated in the pathogenesis of this condition due to its impacts on different organ systems, such as the autonomic nervous system. The present study was performed to investigate the effect of opium use on postoperative arrhythmia in patients undergoing CABG surgery. Methods: Study participants were selected via convenience sampling from patients undergoing CABG surgery in a referral hospital. Study variables, including use of inotropic drugs, vital signs monitoring parameters and postoperative arrhythmia were observed and recorded at baseline and at follow-up time after surgery. Results: Sixty-five (14.8%) patients had postoperative arrhythmia, and 104 participants were addicted. Prevalence of postoperative arrhythmia was the same among addict and non-addict patients. According to the regression analysis model, only serum level of epinephrine in operating room, heart rate and central venous pressure at baseline and 48 hours after operation are known as independent predictors of postoperative arrhythmia among study population. Conclusion: This study showed that although opium addiction increased postoperative arrhythmia among patients undergoing CABG surgery, this difference was not significant, and this association is probably mediated by other study variables.

Práticas relacionadas ao uso do garrote durante a punção venosa periférica: uma revisão de escopo / Health professionals' practices related with tourniquet use during peripheral venipuncture: a scoping review / Prácticas relacionadas al uso del garrote durante la punción venosa periférica: una revisión de alcance

Objetivos durante a punção venosa periférica, recomenda-se o uso de um garrote acima do local da punção para potencializar a distensão venosa. Dadas as suas características e o uso em ambientes clínicos, os garrotes podem representar uma fonte de disseminação de micro-organismos. Entretanto, os resultados de estudos científicos nessa área estão dispersos na literatura. Esta revisão de escopo tem como objetivo mapear as evidências disponíveis a respeito das práticas dos profissionais de saúde no que concerne ao uso do garrote durante a punção venosa periférica e à contaminação microbiológica associada. Método revisão de escopo de acordo com a metodologia do Instituto Joanna Briggs. Dois revisores independentes analisaram a relevância dos estudos, extraíram e sintetizaram dados. Resultados quinze estudos foram incluídos na revisão. Em geral, os garrotes foram reutilizados sem processos de descontaminação recorrentes. Verificou-se que os profissionais compartilham esses dispositivos entre si e os usaram continuamente por períodos entre duas semanas e sete anos e meio. Conclusão as práticas de enfermagem relacionadas ao uso do garrote durante a punção venosa periférica não são uniformes. A reutilização de garrotes pode colocar em risco a segurança do paciente se o reprocessamento (limpeza e desinfecção/esterilização) não for adequado, dado o tipo de material do garrote e a microbiota encontrada. Novos estudos são necessários para avaliar o impacto de vários tipos de práticas de reprocessamento na descontaminação de garrotes e na segurança do paciente.

Objectives during peripheral venipuncture, health professionals are recommended to use a tourniquet above the puncture site in order to potentiate venous distension. Given its characteristics and use in clinical settings, tourniquets may represent a source of microorganism dissemination. However, the results of scientific studies in this area are scattered in the literature. This scoping review aims to map the available evidence on health professionals' practices related with tourniquet use during peripheral venipuncture and associated microbiological contamination. Methods scoping review following the Joanna Briggs Institute methodology. Two independent reviewers analyzed the relevance of the studies, extracted and synthesized data. Results fifteen studies were included in the review. Overall, tourniquets were reused without being subject to recurring decontamination processes. It has been found that practitioners share these devices among themselves and use them successively for periods between two weeks and seven and half years. Conclusion nursing practices related to tourniquet use during peripheral venipuncture are not standard. Reuse of tourniquets may jeopardize the patient's safety if reprocessing (cleaning and disinfection/sterilization) is not adequate, given the type of tourniquet material and microbiota found. New studies are needed to assess the impact of various types of reprocessing practices on tourniquet decontamination and patient safety.

Objetivos durante la punción venosa periférica, se recomienda el uso de un garrote arriba del sitio de la punción para potenciar la distensión venosa. Dadas sus características y uso en ambientes clínicos, los garrotes pueden representar una fuente de diseminación de microorganismos. Sin embargo, los resultados de estudios científicos en esta área están dispersos en la literatura. Esta revisión de alcance tiene como objetivo mapear las evidencias disponibles acerca de las prácticas de los profesionales de salud en lo que concierne al uso del garrote durante la punción venosa periférica y la contaminación microbiológica asociada. Método revisión de alcance de acuerdo con la metodología del Instituto Joanna Briggs. Dos revisores independientes analizaron la relevancia de los estudios, extrajeron y sintetizaron datos. Resultados quince estudios se incluyeron en la revisión. En general, los garrotes fueron reutilizados sin procesos de descontaminación recurrentes. Se verificó que los profesionales comparten estos dispositivos entre sí y los utilizaron continuamente por períodos entre dos semanas y siete años y medio. Conclusión las prácticas de enfermería relacionadas al uso del garrote durante la punción venosa periférica no son uniformes. La reutilización de garrotes puede poner en riesgo la seguridad del paciente si el reprocesamiento (limpieza y desinfección/esterilización) no es adecuado, dado el tipo de material del garrote y la microbiota encontrada. Nuevos estudios son necesarios para evaluar el impacto de varios tipos de prácticas de reprocesamiento en la descontaminación de garrotes y en la seguridad del paciente.

Application of stroke volume variation-guided liquid therapy in laparoscopic precision hepatectomy / 中南大学学报(医学版)

To observe the safety and impact on the short-term prognosis for patients of stroke volume variation (SVV) goal-directed fluid therapy (GDFT) in laparoscopic precision hepatectomy.
 Methods: A total of 120 patients (18-65 years old) undergoing laparoscopic precision hepatectomy were randomly divided into the fluid therapy group (group S) guided by SVV and the fluid therapy group (group C) guided by central venous pressure group (CVP), with 60 cases in each group. Mean arterial pressure (MAP) and heart rate (HR) were recorded at the following time: at home calm (T0), the operation started (T1), began to cut the liver (T2), the hepatectomy was acheived (T3), and in the end (T4). The lactic acid was measured at T0 to T4 and 1 day after surgery (T5). The amount of blood loss, urine output and fluid supplement, the incidence of intraoperative hypotension, and the use of neophryn were recorded. The recovery of liver function, Hb, and so on were also recorded.
 Results: Compared with the group C, the number of hypotension cases, the amount of blood loss and the amount of neophryn in the group S were decreased during the operation (P<0.05), while the lactic acid values in the group S were not significantly increased than those in the group C at T3 and T4 (P<0.05) and the elevation of AST, ALT, DBIL and TBIL in the group S was significantly decreased than those in the group C at 1 and 2 d after the operation (P<0.05). Hb and Hct in the group S were higher than those in the group C at 1 d after the surgery (P<0.05). Compared with the group C, the postoperative exhaust time and hospitalization time were shortened in the group S (P<0.05), and the infection rate and ICU admission rate were decreased in the group S (P<0.05).
 Conclusion: SVV-guided GDFT in laparoscopic precise hepatectomy is safe and effective. It reduces intraoperative blood loss and benefits the short-term prognosis of patients after operations. High SVV value (13%-17%) is adopted at the liver resection stage, and SVV value with 8%-12% at the end of trans-section may be used as one of intraoperative liquid therapy in laparoscopic precise hepatectomy.

Impact of technical innovation on surgical outcome of laparoscopic major liver resection: 10 years' experience at a large-volume center

PURPOSE: Laparoscopic major liver resection (major LLR) remains a challenging procedure because of the technical difficulty. Several significant technical innovations have been applied in our center since 2012. They include routine application of bipolar electrocautery, initiation of temporary increase of intra-abdominal pressure during bleeding events from veins to balance the central venous pressure, and use of temporary inflow control of the Glissonean pedicle. This study evaluated the impact of these technique modifications in patients with major LLR. METHODS: Between January 2004 and February 2015, a total of 606 patients underwent LLR at Samsung Medical Center in Seoul, Korea. Major LLR was employed in 233 cases. All major LLR procedures were anatomical resections performed with a totally laparoscopic approach. We compared surgical parameters of right hepatectomy (RH), left hepatectomy (LH), and right posterior sectionectomy (RPS) before and after 2012. RESULTS: Open conversion rates of RH and LH and estimated blood loss in RPS significantly decreased after 2012. The postoperative complication rate of major LLR was 12.7% and was similar before and after 2012. Bile leakage was the most common complication (3.2%). CONCLUSION: The modifications of surgical techniques resulted in good outcomes for laparoscopic major LLR. We recommend routine application of these techniques to improve outcomes, especially in patients requiring major liver resection.

Effect of apical constriction diameter, irrigant flow rate, and needle tip design on apical pressure / 대한치과재료학회지

The purpose of this study was to evaluate the effects of apical constriction (AC) diameter, irrigant flow rate, and needle tip design on apical pressure (AP) during the root canal irrigation. Five extracted human mandibular premolars were instrumented up to #35 (0.06 taper) using nickel-titanium rotary instruments. AC was determined at 1 mm from the apical foramen. Three needles with different tip designs (notched, side-vented, and flat) were placed 3 mm from AC. APs were measured with varying flow rates of 0.05, 0.1, 0.2, and 0.3 mL/s. The AC diameter of the teeth was enlarged to #40 and #45 (0.06 taper) successively, and the aforementioned measurement procedure was repeated (n=5). When the other conditions were controlled, AP increased with decreasing AC diameter or increasing irrigant flow rate, and the AP of flat needle was the highest, followed by notched, and side-vented needle (p0.35 mm, open-end (notched or flat) needles can be used to improve irrigant replacement in the apical portion using a flow rate of 0.05 mL/s.

Evaluation of suitability of fluid management using stroke volume variation in patients with prone position during lumbar spinal surgery

BACKGROUND: Static parameters such as central venous pressure and pulmonary artery occlusion pressure, have limitation in evaluation of patients' volume status. Dynamic parameters such as stroke volume variation (SVV), have been used to evaluate intraoperative hemodynamic volume status, in various operations. We examined if SVV is also effective for patients undergoing operation with prone position for fluid management. METHODS: Eighteen patients that received spinal surgery under prone position November 2015 to May 2016, were enrolled. Patients were kept at an SVV value less than 14% during surgery. Changes of pre-, post-operative volume status were evaluated, using transthoracic echocardiography. RESULTS: Mean fluid administered was 1,731.97 ± 792.38 ml. Left ventricular end-diastolic volume was 72.85 ± 13.50 ml before surgery, and 70.84 ± 15.00 ml after surgery (P value = 0.594). Right ventricular end-diastolic area was 15.56 ± 1.71 cm² before surgery, and 13.52 ± 2.65 cm² after surgery (P value = 0.110). Inferior vena cava diameter was 14.99 ± 1.74 mm before surgery, and 13.57 ± 2.83 mm after surgery (P value = 0.080). CONCLUSIONS: We can confirm that fluid management based on SVV is effective, even in prone position surgery. So, SVV, that can be measured by continuous arterial pressure, can be considered a guideline for effective fluid management in spinal surgery.

Clinical characteristics of nontraumatic chylothorax in pediatric patients

PURPOSE: To evaluate clinical characteristics of pediatric nontraumaitc chylothorax and to suggest appropriate therapeutic managements. METHODS: We retrospectively reviewed medical records of 22 patients with nontraumatic chylothorax from January 2005 to December 2018 in the Children's Hospital of Seoul National University. We analyze their etiology, treatment, complications and outcome. RESULTS: Of the 22 patients, 16 were diagnosed before 1 year old and 6 after 1 year old. The causes of chylothorax under 1-year-old children were related to congenital factors (n=9), unknown causes (n=5), and high central venous pressure (n=2). The causes of chylothorax over 1-year-old children were related to congenital factors (n=3), unknown causes (n=1), high venous pressure (n=1), and lymphoma (n=1). All patients had dietary modification. Eight of them were cured by dietary modification, but there was no improvement in over 1-year-old children. Medication was added to patients refractory to dietary modification. Four patients with medication were improved and 5 were improved by surgical management. Nutritional, immunological and other complications occurred in many patients. Five death cases were reported. Four patients were under 1 year old and 1 was over 1 year old. The causes of nontraumatic chylothorax in dead patients were high central venous pressure (n=3), congenital (n=1), and unknown (n=1). CONCLUSION: Nontraumatic chylothorax more frequently occurs in under 1-year-old children. The most common cause is congenital factors. Stepwise management is effective in many patients, but specific treatment is needed in some cases. The prognosis is related to the onset of age and underlying diseases.

Enhanced recovery after surgery in liver resection: current concepts and controversies / 대한마취과학회지

Enhanced recovery after surgery (ERAS) attenuates the stress response to surgery in the perioperative period and hastens recovery. Liver resection is a complex surgical procedure where the enhanced recovery program has been shown to be safe and effective in terms of postoperative outcomes. ERAS programs have been shown to be associated with lower morbidity, shortened postoperative stay, and reduced cost with no difference in mortality and readmission rates. However, there are challenges that are unique to hepatic resection such as safety after epidural catheterization and postoperative coagulopathy, intraoperative fluids and postoperative organ dysfunction, need for low central venous pressure to reduce blood loss, and non-lactate containing intravenous fluids. This narrative review briefly discusses these concerns and controversies and suggests revisiting some of the strong recommendations made by the ERAS society in light of the recent evidence.

Indicaciones para el uso del catéter venoso central y el tiempo de colocación en los pacientes hospitalizados en el servicio de medicina interna del hospital Dr. Miguel Pérez Carreño / Indications for the use of the central venous catheter and the time of its use in the patients hospitalized in the internal medicine service of the Dr. Miguel Pérez Carreño hospital

La inserción del catéter venoso central (CVC) ha significado un gran avance en la medicina moderna y su uso generalizado ha permitido el desarrollo de nuevas técnicas diagnósticas y tratamientos especializados. En este estudio se dan a conocer las indicaciones presentes al momento de colocar el catéter venoso central y el tiempo de colocación en los pacientes. Métodos: La investigación fue de tipo retrospectivo, descriptivo y de corte transversal, con un diseño de investigación no experimental y tuvo la finalidad de conocer, en forma directa, la realidad de la problemática. Las unidades de observación fueron(188) historias clínicas de los pacientes que ingresaron en el servicio de medicina interna en el hospital Miguel Pérez Carreño en el periodo comprendido entre enero y abril de 2017. Resultados: El 68% de la indicación del catéter venoso central es para la medición de la presión venosa central (PVC) y control de líquidos, mientras que en el 32% la indicación fue por administración de fármacos. El tiempo de colocación tuvo un predominio del 61% de los pacientes que utilizaron el catéter venoso central durante 1 a 3 semanas, en segundo lugar, el 36% utilizo el catéter por unos días, solo un 3% amerito el uso del catéter venoso central durante 1 mes. Conclusiones: La mayoría de los pacientes estudiados tuvieron como principal indicación de CVC para control de líquido y medición de presión venosa central. Con una duración de 1 a 3 semanas(AU)

The insertion of the central venous catheter (CVC) has meant a great advance in modern medicine and its widespread use has allowed the development of new diagnostic techniques and specialized treatments. In this study we present the indications present at the moment of placing the central venous catheter and the time of use in patients. Methods: The research was of a retrospective, descriptive and cross-sectional type, with a non-experimental research design and aimed to know, in a direct way, the reality of the problem. The units of observation were (188) clinical records of patients admitted to the internal medicine service in the hospital Miguel Pérez Carreño in the period between January and April 2017. Results: 68% of the indication of the central venous catheter is for the measurement of central venous pressure (CVP) and fluid control, while in 32% the indication was for drug administration. The time of use had a predominance of 61% of patients who used the central venous catheter for 1 to 3 weeks, secondly, 36% used the catheter for a few days, only 3% required the use of the central venous catheter for 1 month. Conclusions: The majority of patients studied had CVC as main indication for fluid control and central venous pressure measurement. With a duration of 1 to 3 weeks(AU)

Índice de colapsabilidad de la vena cava inferior como predictor de hipotensión intraoperatoria / Inferior vena cava collapsibility index of the as a predictor of intraoperative hypotension

OBJECTIVE: To evaluate the lower vena cava Collapse Index (CI) as a predictor parameter of hypotensive episodes after general anesthesia induction in ASA I and II patients who were scheduled for elective surgery. MATERIALS AND METHODS: A prospective, observational and simple blind study was designed. A sample of 80 patients was recruited. In the preoperative stage, they underwent protocolarized sedation and CI was obtained. Prior to induction, the baseline values ​​of heart rate, non-invasive mean arterial pressure and continuous electrocardiographic tracing in DII were noted. In the post-orotracheal intubation stage, the aforementioned hemodynamic monitoring variables were recorded manually for 10 minutes. RESULTS: The data of 78 individuals are presented. After anesthetic induction, 8 (10.3%) patients developed hypotension. The adjustment of the univariate logistic regression model for CI shows a good diagnostic capacity, with the area under the ROC curve equal to 0.76. The chance of presenting hypotension is increased by 62% by increasing the CI by 5 points (p = 0.003). Regarding the negative predictive value, we found that with values ​​corresponding to the cutoff points between 39% and 46%, a probability of at least 93.1% of not presenting hypotension was obtained. The optimal cutoff point of the CI to predict hypotension is estimated at 43%, with a sensitivity of 62.5% and a specificity of 92.9%. CONCLUSION: A lower IC was associated with a lower probability of developing intraoperative hypotension. The use of this tool could be useful to anticipate which patients will be prone to intra-surgical hypotension.

OBJETIVO: Evaluar el índice de colapsabilidad (IC) de la vena cava inferior (VCI) como predictor de episodios hipotensivos posinducción de anestesia general en cirugía electiva de pacientes ASA I y II. MATERIALES Y MÉTODOS: Se diseñó un estudio prospectivo, observacional y simple ciego. Se reclutó una muestra de 80 pacientes. En etapa preoperatoria fueron sometidos a una sedación protocolizada y se obtuvo el IC. Previo a la inducción, se anotaron los valores basales de la frecuencia cardíaca, la presión arterial media y el trazado electrocardiográfico continuo en DII. Posintubación orotraqueal, se registraron manualmente las variables hemodinámicas mencionadas durante 10 minutos. RESULTADOS: Se presentan datos de 78 individuos. Luego de la inducción, 8 (10,3%) pacientes desarrollaron hipotensión. El ajuste del modelo de regresión logística univariado para IC muestra una buena capacidad diagnóstica, siendo el área bajo la curva ROC igual a 0,76. La chance de presentar hipotensión se incrementa en un 62% al aumentar el IC en 5 puntos (p = 0,003). En cuanto al valor predictivo negativo, encontramos que con valores correspondientes a los puntos de corte entre 39% y 46%, se obtenía una probabilidad de 93,1% de no presentar hipotensión. El punto de corte óptimo del IC para predecir hipotensión se estima en 43%, con una sensibilidad del 62,5% y una especificidad del 92,9%. CONCLUSIÓN: Un menor IC se asoció con una menor probabilidad de desarrollar hipotensión intraoperatoria. El uso de esta herramienta podría ser de utilidad para anticipar qué pacientes serán propensos a hipotensión intraquirúrgica.

Hemodinámica funcional: ¿Qué significa "ser respondedor"? / Functional hemodynamics: "Be responsive, what does this mean"?

The conventional analysis and approach to the physiology of the fluid responsiveness has traditionally been focused mainly on the physiology of heart-lung interactions, and on reviews of the technical, methodological, and epidemiological aspects of the dynamic parameters, which are translated into simple algorithms to assess fluid responsiveness and to guide fluid therapy.However, fundamental features of the dynamics of the peripheral circulation, heart-vasculature interaction, and blood volume distribution, are overlooked and sometimes not accounted for, motivating misconceptions about the cardiovascular system's response to fluid administration and fluid management, such as equating fluid loading with cardiac preload, a predictable interpretation whenever Starling's ventricular function curve is analyzed in isolation. This paper reexamines fluid responsiveness' rationale offering a broadened perspective on the circulatory phenomena involved in the physiological interaction between BV, cardiac preload and output, and stroke volume variation. Finally, implications relevant in physiological and clinical terms are discussed.

El análisis convencional y abordaje actual de la fisiología de la "respuesta a fluidos" (RF) ha estado focalizada principalmente sobre la fisiología de la interacción cardiopulmonar, y sobre aspectos técnicos, metodológicos y, epidemiológicos de los parámetros dinámicos, los cuales son traducidos en algoritmos simplificados para evaluar la RF y guiar la fluidoterapia. Sin embargo, aspectos fundamentales de la dinámica de la circulación periférica, el acoplamiento entre el corazón y la vasculatura, y la distribución del volumen sanguíneo son frecuentemente omitidos, motivando mal interpretaciones sobre la respuesta del sistema cardiovascular a la administración de fluidos, tal como equiparar la carga de fluidos con la precarga ventricular, una consecuencia predecible al interpretar la curva de función ventricular (Starling) de forma aislada. Así, esta revisión reexamina la rationale de la RF, ofreciendo una perspectiva ampliada sobre aquellos fenómenos circulatorios implicados en la interacción entre el volumen sanguíneo, la precarga ventricular, el gasto cardíaco y la variación del volumen sistólico. Finalmente, se analizarán las implicancias prácticas y conceptuales.

Is there an association between central venous pressure measurement and ultrasound assessment of the inferior vena cava?

Introduction:Early assessment of volume status is paramount in critically ill patients. Central venous pressure (CVP) measurement and ultrasound assessment of the inferior vena cava (IVC) are both used for volume assessment in the emergency centre. Recent data is conflicting over whether there is a correlation between CVP and ultrasound assessment of the IVC.Methods:This was a retrospective review of an audit previously performed in the Emergency Unit of Ngwelezane Hospital in Kwazulu-Natal. The audit involved measuring inferior vena cava collapsibility index (IVC-CI) within 5 min of CVP measurement. In this retrospective study, audit data were analysed to determine if an association exists.Results:Twenty-four patients were included. The median age of participants was 36 (IQR 42) years (95% CI 33­56). The median time to ultrasound was 18.6 (52.5) h (95% CI 7.5­36.2). The mean CVP was 13.7 ±â€¯7.7 cm H2O and mean IVC-CI was 39.4 ±â€¯17.8%. Based on a Pearson correlation test, there was a weak negative correlation between CVP and IVC-CI, which was not statistically significant (r = −0.05, n = 24, p = 0.81, 95% CI −0.5 to 0.4) for all participants. However, among females there was a moderate negative correlation between CVP and IVC-CI, which was not statistically significant (r = −0.43, n = 7, p = 0.34, 95% CI −0.9 to 0.5), while among males there was a weak positive correlation, which was not statistically significant (r = 0.16, n = 17, p = 0.53, 95% CI −0.3 to 0.6).Discussion:There is no significant correlation between CVP and IVC-CI. Further validation research is required to support our preliminary findings of no significant correlation between CVP measurement and ultrasound assessment of the IVC. CVP and IVC ultrasound should be used as clinical adjuncts, and not as stand-alone measures of volume assessment

Heart Transplantation in Patients with Superior Vena Cava to Pulmonary Artery Anastomosis: A Single-Institution Experience

BACKGROUND: Heart transplantation (HTx) can be a life-saving procedure for patients in whom single ventricle palliation or one-and-a-half (1½) ventricle repair has failed. However, the presence of a previous bidirectional cavopulmonary shunt (BCS) necessitates extensive pulmonary artery angioplasty, which may lead to worse outcomes. We sought to assess the post-HTx outcomes in patients with a previous BCS, and to assess the technical feasibility of leaving the BCS in place during HTx. METHODS: From 1992 to 2017, 11 HTx were performed in patients failing from Fontan (n=7), BCS (n=3), or 1½ ventricle (n=1) physiology at Asan Medical Center. The median age at HTx was 12.0 years (range, 3–24 years). Three patients (27.3%) underwent HTx without taking down the previous BCS. RESULTS: No early mortality was observed. One patient died of acute rejection 3.5 years after HTx. The overall survival rate was 91% at 2 years. In the 3 patients without BCS take-down, the median anastomosis time was 65 minutes (range, 54–68 minutes), which was shorter than in the patients with BCS take-down (93 minutes; range, 62–128 minutes), while the postoperative central venous pressure (CVP) was comparable to the preoperative CVP. CONCLUSION: Transplantation can be successfully performed in patients with end-stage congenital heart disease after single ventricle palliation or 1½ ventricle repair. Leaving the BCS in place during HTx may simplify the operative procedure without causing significant adverse outcomes.

Effect of needle tip design and position, and irrigant flow rate on apical pressure / 대한치과재료학회지

The purpose of this study was to evaluate the effect of needle tip design and position, and irrigant flow rate on apical pressure (AP) during root canal irrigation. Five human mandibular premolars were instrumented up to #35 (0.06 taper) using nickel-titanium rotary instruments. Three different needles according to change of needle tip design (notched, side-vented, and flat) were positioned at the point of 1, 3, and 5 mm from the apical constriction (needle tip position). For each needle tip design and position, APs were measured with varying flow rates of 0.05, 0.1, 0.2, and 0.3 ml/s. When the other conditions were controlled, AP increased with decreasing needle tip position or increasing irrigant flow rate (p < 0.05). The AP of flat needle was the highest, followed by notched, side-vented needle for the same needle tip position and irrigant flow rate. The APs at needle tip position of 1 mm or with more than 0.1 ml/s flow rate were higher than central venous pressure (5.88 mmHg) for all conditions. Flat needle was not recommended for clinical use due to sharp increase of AP with changing needle tip position and irrigant flow rate. For safe and effective root canal irrigation, irrigant should be applied with the needle tip position of 3 mm and flow rate of less than 0.05 ml/s.