Patient Volume Research Articles

Comparison between minimally invasive surgery and open surgery in managing localized adrenocortical carcinoma treatment: Aretrospective propensity-matched study.

It was controversial to use open surgery or minimally invasive surgery (MIS) for adrenocortical carcinoma (ACC). This retrospective study aimed to evaluate the impact on prognosis between MIS and open surgery in patients with clinical stage I-II ACC. Patients with stage I-II ACC from December 2000 to October 2022 were retrospectively studied. The primary endpoint was recurrence-free survival time calculated by the Kaplan-Meier curves. In total, 95 patients were enrolled in this study (50 open surgery and 45 MIS). Propensity score matching identified 32 matched pairs of patients. Compared with the open surgery group, the MIS group had a shorter median operative time (150.0 vs. 120.0 min, p = 0.014), the lesser median volume of intraoperative blood loss (200.0 vs. 60.0 mL, p = 0.006), lower incidence of postoperative complications (59.4% vs. 28.1%, p = 0.023), and shorter median postoperative length of hospital stay (8.0 vs. 7.0 days, p = 0.001). After a median follow-up time of 20.5 months, no significant differences were observed in the local recurrence rate (62.5% vs. 78.1%), distant metastasis rate (15.6% vs. 6.3%), and median time to recurrence (15.0 vs. 20.0 months) between the two groups. The median recurrence-free survival time between the open surgery and MIS groups did not significantly differ (16.0 vs. 21.0 months). MIS might be a feasible option for treating localized ACC at a high patient's volume center with experienced surgeons.

Demystifying Volume Status: An Ultrasound-Guided Physiologic Framework.

Accurate assessment of a patient's volume status is crucial in many conditions, informing decisions on fluid prescribing, vasoactive agents, and decongestive therapies. Determining a patient's volume status is challenging, due to limitations in examination and investigations and the complexities of fluid homeostasis in disease states. Point-of-care ultrasound (POCUS) is useful in assessing hemodynamic parameters related to volume status, fluid responsiveness, and fluid tolerance. It requires understanding several physiologic concepts to accurately interpret and integrate POCUS findings into volume-related clinical decision-making. The following concepts serve as a scaffold for a comprehensive volume status assessment: central venous pressure, right heart function, left heart assessment, extravascular volume, and venous congestion. POCUS allows us access to these hemodynamic and structural data points as an extension and refinement of the physical exam. Often, multiple POCUS applications are employed, and findings must be integrated with the rest of the clinical evaluation. We illustrate this using three common scenarios: hypotension, hypoxia, and acute kidney injury. Clinicians must be aware of the strengths and weaknesses of findings in different physiologic states, and potential pitfalls of image acquisition and interpretation. Further studies are necessary to determine the benefits and clinical outcomes of a POCUS-directed volume status assessment. Volume status assessment is ubiquitous, yet challenging to perform. This review summarizes foundational physiologic concepts relevant to volume status evaluation, and highlights how multiorgan POCUS informs on hemodynamic parameters that can be combined with the conventional clinical assessment to make fluid-related decisions.

Volume Status among Hyponatremic admitted Patients

Introduction: The kidneys play a vital role in the management of hyponatremic patients with fluid disturbances. This task becomes more challenging in presence of comorbidities like chronic kidney disease or congestive heart failure. Accurate assessment of volume status and urinary sodium excretion is essential part for the correct management.. Both impaired renal function and compromised left ventricular function complicate the accurate evaluation of a patient's fluid status. Method: This cross-sectional prospective study was conducted over 262 adult patients with hyponatremia at The Indus Hospital, Karachi from 2017 to 2020. The patient's volume status at the time of enrollment was categorized as normovolemic, hypovolemic, or hypervolemic based on clinical examination. Spot urine sodium, chloride, potassium, urine and serum osmolality, serum urea, and Random blood sugar were all done. Results: There was a total of 262 patients in which 123 (46.9%) were male and 139 (53.1%) were female. The mean age was 54.1 ± 16.4 years. The overall comorbid burden was high 227(86.64%), in which hypertension and CKD contributed more. Out of 262 patients, half of them suffered from hypovolemia 131(50%). Spot urine sodium (>20 meq) was found in 219(83.58/%) patients, in which predominant volume status was hypovolemia 104(47.5%). Moreover, among those who could not survive were 28 (10.7%), in which hypovolemia contributed more than other volume status 12(42.85%). Conclusion: Hypovolemia came out to be the predominant volume status among hyponatremic patients with high comorbid burden. Majority excreted more sodium in spot urine sample despite of hypovolemia in majority.

Measures of wave intensity as a non-invasive surrogate for cardiac function predicts mortality in haemodialysis patients.

Risk prediction in haemodialysis (HD) patients is challenging due to the impact of the dialysis regime on the patient's volume status and the complex interplay with cardiac function, comorbidities and hypertension. Cardiac function as a key predictor of cardiovascular (CV) mortality in HD patients is challenging to assess in daily routine. Thus the aim of this study was to investigate the association of a novel, non-invasive relative index of systolic function with mortality and to assess its interplay with volume removal. A total of 558 (373 male/185 female) HD patients with a median age of 66years were included in this analysis. They underwent 24-hour ambulatory blood pressure monitoring, including wave intensity analysis [i.e. S:D ratio (SDR)]. All-cause and CV mortality served as endpoints and multivariate proportional hazards models were used for risk prediction. Intradialytic changes were analysed in tertiles according to ultrafiltration volume. During a follow-up of 37.8months, 193 patients died (92 due to CV reasons). The SDR was significantly associated with all-cause {univariate hazard ratio [HR] 1.36 [95% confidence interval (CI) 1.20-1.54], P<.001} and CV [univariate HR 1.41 (95% CI 1.20-1.67), P<.001] mortality. The associations remained significant in multivariate analysis accounting for possible confounders. Changes in the SDR from pre-/early- to post-dialytic averages were significantly different for the three ultrafiltration volume groups. This study provides well-powered evidence for the independent association of a novel index of systolic function with mortality. Furthermore, it revealed a significant association between intradialytic changes of the measure and intradialytic volume removal.

#607 Pre- and post-hemodialysis differences in heart failure diagnosis by current heart failure guidelines in patients with end-stage renal disease

Abstract Background and Aims Patients with end-stage renal disease (ESRD) who are on hemodialysis (HD) have reduced vascular compliance and are likely to develop heart failure (HF). Dialysis patients experience a volume change of ∼3–4 kg before and after HD, which can affect hemodynamic indicators, some of which are highly influenced by a patient's volume status. Therefore, depending on when echocardiography is performed, there may be differences in hemodynamic parameters. However, it is not easy to perform echocardiography in the euvolemic state in the clinical setting. This study estimated pre- and post-HD in ESRD HF diagnosis prevalence using the current guidelines. Method We prospectively investigated ESRD patients on HD using echocardiography between pre and post HD. We used structural or functional abnormality criteria of 2021 ESC guideline. Results A total of 54 patients were enrolled. The mean age was 62.6 years and 40.1% were male. Forty-five patients (83.3%) had hypertension, 28 (51.9%) had diabetes, 20 (37.0%) had ischemic heart disease. Mean NT-pro BNP level was 11959.9pg/dL. The mean ideal body weight was 59.3 kg, mean hemodialysis time was 237.4 minutes, and mean real filtration was 2.8 kg. The mean LVEF was 62.4% and mean LVEDD was 52.0 mm in pre-HD. Post-HD echocardiography showed significantly lower LAVI (33.3 ± 15.9 vs. 40.6 ± 17.1, p = 0.030), TR jet V (2.5 ± 0.4 vs. 2.8 ± 0.4 m/s, p &amp;lt; 0.001), and RVSP (32.1 ± 10.3 vs. 38.4 ± 11.6, p = 0.005) compared with pre-HD. There was no difference in LVEF, E/E’ ratio, or LV GLS. A total of 88.9% for pre-HD and 66.7% for post-HD had at least structural or functional abnormalities in echocardiographic parameters according to recent HF guidelines, p = 0.007). Conclusion Our data showed that the majority of patients undergoing hemodialysis satisfy the diagnostic criteria for HF according to current HF guidelines, and the difference of prevalence of HF was 22.2% between pre- and post- HD.

Fluid balance versus weighing: A comparison in ICU patients: A single center observational study.

The fluid balance is a critical parameter in intensive care units (ICU) as it provides information about the patient's volume status. However, the accuracy of fluid balance measurements is often compromised due to the complexity and repetition of actions involved. Additionally, the fluid balance could be recalculated for insensible fluid loss. Weighing is an alternative method to estimate the patient's volume status. Built-in scales in beds make patient weighing easier and less time-consuming, allowing clinicians to intervene more quickly on existing treatments. This study compares fluid balance, and body weight changes over time in ICU patients. Furthermore, it seeks to determine the degree of congruence between the fluid balance corrected for insensible fluid loss and daily body weight in ICU patients. A single-center observational study was conducted in an ICU of a university hospital. All consecutive patients admitted to a bed with an integrated weighing scale were eligible. Exclusion criteria were (1) body weight ≥254,4 kilograms; (2) oral nutrition; (3) a flush catheter or balance; (4) only a single weight measurement; (5) delta body weight change of ≥5kg in 12 hours. Weights and fluid balances were obtained every 12 hours. We obtained 2282 measurements (n = 187 patients). The correlation between weight and fluid balance was weak (r = 0.274). After adjusting the fluid balance for insensible fluid loss, the correlation remained weak (r = 0,268). Bland Altman analysis revealed a wide confidence interval for both the fluid balance and corrected fluid balance versus weight. This study shows a weak correlation between weight and fluid balance. Therefore, when monitoring the volume status in the ICU, fluid balance and weight should both be taken into account. This two-pronged approach is crucial because it provides more control over erroneous fluid balance or weighing measurements.

HistoriView: Implementation and Evaluation of a Novel Approach to Review a Patient Using a Scalable Space-Efficient Timeline without Zoom Interactions.

Timelines have been used for patient review. While maintaining a compact overview is important, merged event representations caused by the intricate and voluminous patient data bring event recognition, access ambiguity, and inefficient interaction problems. Handling large patient data efficiently is another challenge. This study aims to develop a scalable, efficient timeline to enhance patient review for research purposes. The focus is on addressing the challenges presented by the intricate and voluminous patient data. We propose a high-throughput, space-efficient HistoriView timeline for an individual patient. For a compact overview, it uses nonstacking event representation. An overlay detection algorithm, y-shift visualization, and popup-based interaction facilitate comprehensive analysis of overlapping datasets. An i2b2 HistoriView plugin was deployed, using split query and event reduction approaches, delivering the entire history efficiently without losing information. For evaluation, 11 participants completed a usability survey and a preference survey, followed by qualitative feedback. To evaluate scalability, 100 randomly selected patients over 60 years old were tested on the plugin and were compared with a baseline visualization. Most participants found that HistoriView was easy to use and learn and delivered information clearly without zooming. All preferred HistoriView over a stacked timeline. They expressed satisfaction on display, ease of learning and use, and efficiency. However, challenges and suggestions for improvement were also identified. In the performance test, the largest patient had 32,630 records, which exceeds the baseline limit. HistoriView reduced it to 2,019 visual artifacts. All patients were pulled and visualized within 45.40 seconds. Visualization took less than 3 seconds for all. HistoriView allows complete data exploration without exhaustive interactions in a compact overview. It is useful for dense data or iterative comparisons. However, issues in exploring subconcept records were reported. HistoriView handles large patient data preserving original information in a reasonable time.

Renal Congestion in Heart Failure: Insights in Novel Diagnostic Modalities.

Heart failure is increasingly prevalent and is estimated to increase its burden in the following years. A well-reported comorbidity of heart failure is renal dysfunction, where predominantly changes in the patient's volume status, tubular necrosis or other mechanical and neurohormonal mechanisms seem to drive this impairment. Currently, there are established biomarkers evaluating the patient's clinical status solely regarding the cardiovascular or renal system. However, as the coexistence of heart and renal failure is common and related to increased mortality and hospitalization for heart failure, it is of major importance to establish novel diagnostic techniques, which could identify patients with or at risk for cardiorenal syndrome and assist in selecting the appropriate management for these patients. Such techniques include biomarkers and imaging. In regards to biomarkers, several peptides and miRNAs indicative of renal or tubular dysfunction seem to properly identify patients with cardiorenal syndrome early on in the course of the disease, while changes in their serum levels can also be helpful in identifying response to diuretic treatment. Current and novel imaging techniques can also identify heart failure patients with early renal insufficiency and assess the volume status and the effect of treatment of each patient. Furthermore, by assessing the renal morphology, these techniques could also help identify those at risk of kidney impairment. This review aims to present all relevant clinical and trial data available in order to provide an up-to-date summary of the modalities available to properly assess cardiorenal syndrome.

Early Autocalibrated Arterial Waveform Analysis for the Management of Burn Shock-A Cohort Study.

Adequate fluid therapy is crucial for resuscitation after major burns. To adapt this to individual patient demands, standard is adjustment of volume to laboratory parameters and values of enhanced hemodynamic monitoring. To implement calibrated parameters, patients must have reached the intensive care unit (ICU). The aim of this study was, to evaluate the use of an auto-calibrated enhanced hemodynamic monitoring device to improve fluid management before admission to ICU. We used PulsioflexProAqt® (Getinge) during initial treatment and burn shock resuscitation. Analysis was performed regarding time of measurement, volume management, organ dysfunction, and mortality. We conducted a monocentre, prospective cohort study of 20 severely burned patients, >20% total body surface area (TBSA), receiving monitoring immediately after admission. We compared to 57 patients, matched in terms of TBSA, age, sex, and existence of inhalation injury out of a retrospective control group, who received standard care. Hemodynamic measurement with autocalibrated monitoring started significantly earlier: 3.75(2.67-6.0) hours (h) after trauma in the study group versus 13.6(8.1-17.5) h in the control group (P < .001). Study group received less fluid after 6 h: 1.7(1.2-2.2) versus 2.3(1.6-2.8) ml/TBSA%/kg, P = .043 and 12 h: 3.0(2.5-4.0) versus 4.2(3.1-5.0) ml/TBSA%/kg, P = .047. Dosage of norepinephrine was higher after 18 h in the study group: 0.20(0.12-0.3) versus 0.08(0.02-0.18) µg/kg/min, P = .014. The study group showed no adult respiratory distress syndrome versus 21% in the control group, P = .031. There was no difference in other organ failures, organ replacement therapy, and mortality. The use of auto-calibrated enhanced hemodynamic monitoring is a fast and feasible way to guide early fluid therapy after burn trauma. It reduces the time to reach information about patient's volume capacity. Management of fluid application changed to a more restrictive fluid use in the early period of burn shock and led to a reduction of pulmonary complications.

Heart-Lung Interactions.

The pulmonary and cardiovascular systems have profound effects on each other. Overall cardiac function is determined by heart rate, preload, contractility, and afterload. Changes in lung volume, intrathoracic pressure (ITP), and hypoxemia can simultaneously change all of these four hemodynamic determinants for both ventricles and can even lead to cardiovascular collapse. Intubation using sedation depresses vasomotor tone. Also, the interdependence between right and left ventricles can be affected by lung volume-induced changes in pulmonary vascular resistance and the rise in ITP. An increase in venous return due to negative ITP during spontaneous inspiration can shift the septum to the left and cause a decrease in left ventricle compliance. During positive pressure ventilation, the increase in ITP causes a decrease in venous return (preload), minimizing ventricular interdependence and will decrease left ventricle afterload augmenting cardiac output. Thus, positive pressure ventilation is beneficial in acute heart failure patients and detrimental in hypovolemic patients where it can cause a significant decrease in venous return and cardiac output. Recently, this phenomenon has been used to assess patient's volume responsiveness to fluid by measuring pulse pressure variation and stroke volume variation. Heart-lung interaction is very dynamic and changes in lung volume, ITP, and oxygen level can have various effects on the cardiovascular system depending on preexisting cardiovascular function and volume status. Heart failure and either hypo or hypervolemia predispose to greater effects of ventilation of cardiovascular function and gas exchange. This review is an overview of the basics of heart-lung interaction.

Native T2 Predicts Myocardial Inflammation Irrespective of a Patient's Volume Status.

Myocardial inflammation and edema are major pathological features in myocarditis. Myocardial tissue water content and myocardial edema can be quantified via T2 mapping. Thus, cardiac magnetic resonance (CMR) is the noninvasive gold standard for diagnosing myocarditis. Several studies showed an impact of short-term volume changes on T2 relaxation time. Plasma volume status (PVS) is a good surrogate parameter to quantify a patient's volume status, and it is simple to use. The aim of this study was to determine the effect of PVS on the diagnostic value of T2 relaxation time in myocardial inflammation. Between April 2017 and December 2022, patients who were indicated for cardiac CMR were included in our prospective clinical registry. Patients with myocardial inflammation and those with unremarkable findings were analyzed in the present study. A blood sample was drawn, and PVS was calculated. Patients were separated into PVS tertiles to explore a possible nonlinear dose-response relationship. Logistic regression analysis was used to determine whether T2 is an independent predictor of myocardial inflammation. A total of 700 patients (47.43% female) were eligible for analysis. Of these, 551 patients were healthy (78.7%), while 149 (21.3%) showed signs of myocardial inflammation. The T2 relaxation time was elevated in patients with myocardial inflammation (40 ms [IQR 37-42 ms] vs. 38.0 ms [IQR 36-39 ms], p < 0.001). PVS showed no difference between the groups (-12.94 [IQR -18.4--7.28] vs.-12.19 [IQR -18.93--5.87], p = 0.384). T2 showed a clear dose-response relationship with PVS, with increasing T2 values along the PVS tertiles. In spite of this, T2 was found to be an independent marker of myocardial inflammation in logistic regression (OR T2 1.3 [95% CI 1.21-1.39], p < 0.001), even after adjusting for PVS (OR T2 [adj. PVS] 1.31 [95% CI 1.22-1.40], p < 0.001). Despite a dose-response relationship between T2 and the volume status, T2 was found to be an independent indicator of myocardial inflammation.

ESTIMATION OF PLASMA VOLUME IN PATIENTS PRESENTING WITH ACUTE DECOMPENSATED HEART FAILURE USING KAPLAN – HAKIM FORMULA AND CORRELATION OF PLASMA VOLUME SHIFT WITH OUTCOMES

Objective: Simple and non-invasive methods are required to estimate the plasma volume expansion to assess the congestion status in heart failure patients. To determine the effectiveness of Kaplan–Hakim formula in the quantification of the plasma volume expansion in acute decompensated heart failure (ADHF) and the correlation of the outcome factors with plasma volume shift (PVS). Methods: This prospective study included 384 participants diagnosed with ADHF. Newly diagnosed cases and patients receiving treatment for the past 6 months were included. Kaplan–Hakim formula was used to estimate the plasma volume. Duration of hospital stay, subsequent hospitalization for heart failure (HHF), cardiovascular disease mortality, and all-cause mortality rate at the end of follow-up time was also noted. Results: Among the study participants, 88 patients (22.92%) had PVS &lt;5%, while the remaining 88.5% of the patients had PVS more than or equal to 5%. A strong association between guideline-recommended dose of ACEi/ARBs, beta-blockers, and normalcy of plasma volume status (p&lt;0.001) was found. The mean duration of stay, number of repeated hospitalization, the incidence of worsening renal function, CV mortality rate, and all-cause mortality rate were significantly lower in participants with PVS ≥5% in comparison to those who had PVS &lt; 5%. Kaplan–Hakim formula is a more practical and easy way to measure volume status in patients with ADHF. Conclusion: The use of RAAS antagonists and beta-blockers in their optimal dosage is associated with favorable plasma volume status in chronic HF patients.

Pulsatile Femoral Vein Doppler Pattern is a Parameter of Venous Congestion in ICU Patients

ObjectivesThe aim of this study was to evaluate whether the presence of a pulsatile femoral vein pattern is and indicator of venous congestion in ICU; DesignRetrospective observational study; SettingThree medico-surgical university-affiliated ICUs; ParticipantsAdult patients who had ultrasound evaluation at several time points during ICU stay: at baseline (within 24h of admission to ICU), and/or daily during ICU stay, and/or within 24h before ICU discharge; InterventionsAt each time point, the hemodynamic, respiratory and cardiac ultrasound parameters were recorded. The common femoral vein was studied with pulsed-wave Doppler at the level of the femoral trigonum, with high frequency (5–13 MHz) linear array vascular probe and venous vascular mode, in supine patients. Measurements and Main resultsOne hundred-and-eight patients who underwent 400 ultrasound evaluations (3.7 ± 1 ultrasound evaluations per patient) during their ICU stay were included. 79/108 patients (73%) had a pulsatile femoral vein pattern at least at one timepoint. The multivariable mixed effects logistic regression model demonstrated an association between pulsatile femoral vein pattern, BMI (OR: 0.91(CI95%: 0.85-0.96), p=0.002), IVC mean diameter (OR:2.35 (CI95%: 1.18-4.66), p=0.014), portal vein pulsatility (OR: 2.3 (CI95%:1.2-4.4), p=0.012), and congestive renal vein flow pattern (OR: 4.02 (CI95%: 2.01-8.03), p<0.001). The results were confirmed by principal component analysis. ConclusionIn ICU, a pulsatile femoral vein pattern is associated with parameters of venous congestion, independently of patient's volume status, and ventilatory treatment. These results suggest the femoral vein Doppler pulsatility as a parameter of congestion in ICU patients.

Native T1 is predictive of cardiovascular death/heart failure events and all-cause mortality irrespective of the patient's volume status.

Native T1 has become a pivotal parameter of tissue composition that is assessed by cardiac magnetic resonance (CMR). It characterizes diseased myocardium and can be used for prognosis estimation. Recent publications have shown that native T1 is influenced by short-term fluctuations of volume status due to hydration or hemodialysis. Patients from a prospective BioCVI all-comers clinical CMR registry were included, and native T1 and plasma volume status (PVS) were determined according to Hakim's formula as surrogate markers of patient volume status. The primary endpoint was defined as combined endpoint of cardiovascular death or hospitalization for heart failure events, the secondary endpoint was defined as all-cause mortality. A total of 2,047 patients were included since April 2017 [median (IQR); age 63 (52-72) years, 33% female]. There was a significant although weak influence of PVS on native T1 (β = 0.11, p < 0.0001). Patients with volume expansion (PVS > -13%) showed significantly higher values for tissue markers than non-volume-overloaded patients [PVS ≤ -13%; median (IQR); native T1 1,130 (1,095-1,170) vs. 1,123 (1,086-1,166) ms, p < 0.003; and T2 39 (37-40) vs. 38 (36-40) ms, p < 0.0001]. In Cox regression analysis both native T1 and PVS were independently predictive of the primary endpoint and all-cause mortality. Despite a weak effect of PVS on native T1, its predictive power was not affected in a large, all-comers cohort.

The E/e' Ratio: As "Critical" As the Left Ventricular Ejection Fraction?

Ascertainment of the left ventricular ejection fraction is the primary reason for ordering echocardiography in the acute care setting; however, this parameter does not provide information regarding a patient's volume status. As such, it cannot be reliably used to inform decisions regarding intravenous fluid resuscitation or diuresis, particularly in undifferentiated dyspnea and hypotension. This is relevant given a national quality improvement exhortation to provide aggressive fluid resuscitation as part of a "sepsis bundle." This initiative must be tempered by the well-established increase in hospital mortality from providing intravenous fluid to patients with unrecognized heart failure, which may occur if sepsis is misdiagnosed. We describe herein, what is to our knowledge, the first description of a critically elevated Doppler ratio of mitral inflow peak E-wave velocity to the mean mitral annular velocity as a harbinger of sudden death from pulmonary edema in a patient treated with aggressive intravenous fluids as part of the "sepsis bundle." This is utilized as a springboard for proposing a clinical algorithm focused on expedited echocardiography. It emphasized the potential value of advancing markedly the diastolic assessment of filling pressure (ratio of mitral inflow peak E-wave velocity to the mean mitral annular velocity) in the acute care setting to a level of import comparable to the left ventricular ejection fraction.

IVC measurement for the noninvasive evaluation of central venous pressure.

Central venous pressure (CVP) is one of only a handful of variables that can be used to assess a patient's volume status to attempt to optimize stroke volume. The gold standard method for assessing CVP is though pulmonary artery catheterization, which is invasive and risks severe complications such as pneumothorax and cardiac conduction abnormalities. Current noninvasive methods for estimating CVP such as jugular venous pressure assessment are imperfect with wide inter-examiner variability. The inferior vena cava (IVC) is a highly compliant vessel that uniquely does not constrict in response to hypovolemia, making it an ideal, noninvasive surrogate for the estimation of CVP. A range of IVC indices including minimum and maximum IVC diameter and fraction of IVC collapse with inspiration (known as collapsibility index) have been studied with highly variable results that range from excellent to poor correlation between these values and CVP. Despite this inconsistency in findings, multiple schemes have been proposed to attempt to estimate CVP from IVC measurements, but when prospectively tested, none has been shown to be accurate. Since the most recent 2015 American Society of Echocardiography guidelines, multiple studies have identified unique ways of improving the accuracy of IVC measurement, which could translate into better CVP estimation. The goal of this review is to summarize the many, often conflicting studies that exist in this area, and provide recommendations for future studies based on our findings.

Correlation of Inferior Vena Cava diameter and IVC Collapsibility Index with Central Venous Pressure (CVP) in critically ill surgical patients

Introduction: Central Venous Pressure is a valuable parameter in the management of critically ill surgical patients in the ICU. Non-invasive methods to extrapolate the volume status of the patient can aid clinicians in expediting proper treatment. The objective of this study is to find a correlation between Inferior Vena cava (IVC) diameter and collapsibility index (CI) with Central venous pressure (CVP) in critically ill surgical patients. Methods: This cross-sectional study included 60 critically ill patients from September 2020 – 31st February 2021. We recorded the patient's age, sex, heart rate, blood pressure, CVP, volume status, IVC minimum, and maximum diameter. After taking consent and explaining the procedure to the patient, the maximum IVC anteroposterior diameter was noted at the end of inspiration and end of expiration in centimeters. IVC collapsibility index was calculated using the formula ([IVCdmax-IVCdmin]/IVCdmax*100%). Following this, the CVP of the patient was measured. Results: Among the patients evaluated, 32 were females. The mean age of the participants was 44.90 ± 15.76 years. The mean central venous pressure maintained was 11.10 ± 2.11cm H2O with an inferior vena cava collapsibility index of 29.69 ± 8.75. There was a negative correlation between CVP and IVC collapsibility index (%), which was statistically significant (r = -0.701, n = 60, p &lt; 0.01). A strong positive correlation between CVP and maximum IVC diameter (r = 0.712, n = 60, p &lt; 0.01) and minimum IVC diameter (r = 0.796, n = 60, p &lt; 0.01) was found. Conclusion: Inferior Vena Cava diameter and IVC Collapsibility Index can be used as a reliable substitute to central venous pressure to determine the patient's volume status.

Pharmacological therapy of circulatory shock

Circulatory shock requires treatment of the underlying pathology in addition to supportive pharmacological therapy that is guided by hemodynamic monitoring. Based on the evaluation of the patient's volume, perfusion and cardiac status, the following therapeutic goals should be achieved: (1)Normalization of the intra- and extravascular fluid volume. (2)Provision of sufficient perfusion pressure and organ perfusion. (3)Optimization of cardiac function including protecting an ischemic and exhausted myocardium from overload. The most important therapeutic substances are balanced electrolyte solutions and the vasopressor noradrenaline. Because there is little scientific evidence for the use of alternative drugs, these should only be given if there is agood pathophysiologic rationale and if their effect is continuously monitored and re-evaluated.

Half the V by 120: A practical approach to the prevention of the dialysis disequilibrium syndrome.

The dialysis disequilibrium syndrome (DDS) results from osmotic shifts between the blood and the brain compartments. Patients at risk for DDS include those with very elevated blood urea nitrogen, concomitant hypernatremia, metabolic acidosis, and low total body water volumes. By understanding the underlying pathophysiology and applying urea kinetic modeling, it is possible to avoid the occurrence of this disorder. A urea reduction ratio (URR) of no more than 40%-45% over 2 h is recommended for the initial hemodialysis treatment. The relationship between the URR and Kt/V is useful when trying to model the dialysis treatment to a specific URR target. A simplified relationship between Kt/V and URR is provided by the equation: Kt/V=-ln (1 - URR). A URR of 40% is roughly equivalent to a Kt/V of 0.5. The required dialyzer urea clearance to achieve this goal URR in a 120-min treatment can simply be calculated by dividing half the patient's volume of distribution of urea by 120. The blood flow rate and dialyzer mass transfer coefficient (K0 A) required to achieve this clearance can then be plotted on a nomogram. Other methods to reduce the risk of DDS are reviewed, including the use of continuous renal replacement therapy.

Assessment of Volume Status and Fluid Responsiveness in Small Animals.

Intravenous fluids are an essential component of shock management in human and veterinary emergency and critical care to increase cardiac output and improve tissue perfusion. Unfortunately, there are very few evidence-based guidelines to help direct fluid therapy in the clinical setting. Giving insufficient fluids and/or administering fluids too slowly to hypotensive patients with hypovolemia can contribute to continued hypoperfusion and increased morbidity and mortality. Similarly, giving excessive fluids to a volume unresponsive patient can contribute to volume overload and can equally increase morbidity and mortality. Therefore, assessing a patient's volume status and fluid responsiveness, and monitoring patient's response to fluid administration is critical in maintaining the balance between meeting a patient's fluid needs vs. contributing to complications of volume overload. This article will focus on the physiology behind fluid responsiveness and the methodologies used to estimate volume status and fluid responsiveness in the clinical setting.