Current practice of hemodynamic monitoring and vasopressor and inotropic therapy in post-operative cardiac surgery patients in Germany: results from a postal survey

Comparison of clinical results between transpulmonary thermodilution monitoring and conventional methods in cardiac surgery: An observational study

The Pulse Index Contour Continuous Cardiac Output (PICCO) module provides advanced and continuous monitoring of cardiac output through the use of arterial pulse contour analysis and transpulmonary thermodilution. The objective of this study was to compare the early postoperative outcomes of patients who were monitored using the conventional method and the pulse contour analysis method. A prospective observational study was conducted involving 45 patients who underwent cardiac surgery between 2020 and 2022. Patients were randomly assigned to either Group P (PICCO) or Group C (conventional). In the PICCO cohort, a femoral artery cannula was inserted for the continuous recording and management of hemodynamic data, in accordance with the decision-making algorithm of the module. In the conventional group, cannulation of the radial artery and jugular vein was performed. The postoperative hemodynamic and clinical data are subjected to analysis. The utilization of dopamine was markedly diminished in Group P at both the 0- and 6-hour postoperative intervals, whereas the administration of dobutamine was observed to be elevated (P = .008). The frequency of red packed cell transfusions was higher in Group C at postoperative hour 0. Hemodynamic data indicated a 42% increase in cardiac index and a 33% decrease in systemic vascular resistance, along with a 33% increase in global ejection fraction in patients monitored with PICCO. The mortality rates observed in the 2 groups were not statistically different. The implementation of advanced monitoring techniques, specifically the PICCO module, led to notable enhancements in hemodynamic parameters. The utilization of this technique may prove advantageous in guiding inotrope selection and transfusion decisions during the initial postoperative period. However, it is important to note that morbidity and mortality rates remain comparable.

Evaluation of Electrical Cardiometry to Assess Fluid Responsiveness in Patients with Acute Circulatory Failure: A Comparative Study with Transthoracic Echocardiography

Aim

Acute circulatory failure is commonly encountered in critically ill patients, that requires fluid administration as the first line of treatment. However, only 50% of patients are fluid-responsive. Identification of fluid responders is essential to avoid the harmful effects of overzealous fluid therapy. Electrical cardiometry (EC) is a non-invasive bedside tool and has proven to be as good as transthoracic echocardiography (TTE) to track changes in cardiac output. We aimed to look for an agreement between EC and TTE for tracking changes in cardiac output in adult patients with acute circulatory failure before and after the passive leg-raising maneuver.

Materials and methods

Prospective comparative study, conducted at a Tertiary Care Teaching Hospital.

Results

We recruited 125 patients with acute circulatory failure and found 42.4% (53 out of 125) to be fluid-responsive. The Bland-Altman plot analysis showed a mean difference of 2.08 L/min between EC and TTE, with a precision of 3.8 L/min. The limits of agreement (defined as bias ± 1.96SD), were -1.7 L/min and 5.8 L/min, respectively. The percentage of error between EC and TTE was 56% with acceptable limits of 30%.

Conclusion

The percentage error beyond the acceptable limit suggests the non-interchangeability of the two techniques. More studies with larger sample sizes are required to establish the interchangeability of EC with TTE for tracking changes in cardiac output in critically ill patients with acute circulatory failure.

How to cite this article

Sharma S, Ramachandran R, Rewari V, Trikha A. Evaluation of Electrical Cardiometry to Assess Fluid Responsiveness in Patients with Acute Circulatory Failure: A Comparative Study with Transthoracic Echocardiography. Indian J Crit Care Med 2024;28(7):650-656.

Timing of Blood Transfusions and 30-Day Patient Outcomes After Coronary Artery Bypass Graft Surgery

OBJECTIVE

Packed red blood cell transfusion during coronary artery bypass graft surgery is known to be associated with adverse outcomes. However, the association of the timing between transfusions in relation to discharge and 30-day postoperative outcomes has not been studied. The study authors investigated the impact of transfusion timing on 30-day surgical outcomes.

DESIGN

A retrospective review.

SETTING

At a single tertiary-care academic hospital.

PARTICIPANTS

A total of 2,481 adult patients underwent primary coronary artery bypass graft surgery between January 2014 and December 2020.

MEASUREMENTS AND MAIN RESULTS

The relationship between the timing of packed red blood cell transfusion (intraoperative, postoperative, or both) and 30-day postoperative outcome variables was calculated as an odds ratio. The influence of timing of transfusion on adjusted probability of postoperative complications was plotted against the lowest intraoperative hematocrit. The median age of the population was 67 years (60.0-74.0), body mass index was 28.5 (25.6-32.3) kg/m², and 497 (20.0%) were female. A total of 1,588 (36%) patients received packed red blood cell transfusions; 182 (7.3%) received intraoperative transfusions, 489 (19.7%) received postoperative transfusions, and 222 (9.0%) received both (intraoperative and postoperative transfusions). Postoperative transfusion was associated with significantly higher odds of readmission (1.83 [1.32-2.54], p = 0.002) and heart failure (1.64 [1.2-2.23], p = 0.008) compared to patients with no transfusions; whereas intraoperative transfusions were not.

CONCLUSION

The authors' data suggested that the postoperative timing of transfusion in patients undergoing coronary artery bypass graft surgery may be associated with an increased incidence of 30-day heart failure and readmission. Prospective research is needed to conclusively confirm these findings.

Should central venous pressure be used to guide critical care management?

Central venous pressure is no longer routinely used to guide therapy in UK intensive care units, owing to evidence that it poorly predicts fluid responsiveness. This article reviews whether central venous pressure monitoring should be used to guide critical care management in certain patients.

Effect of Volatile Anesthetics on Myocardial Infarction After Coronary Artery Surgery: A Post Hoc Analysis of a Randomized Trial

OBJECTIVE

To investigate the effect of volatile anesthetics on the rates of postoperative myocardial infarction (MI) and cardiac death after coronary artery bypass graft (CABG).

DESIGN

A post hoc analysis of a randomized trial.

SETTING

Cardiac surgical operating rooms.

PARTICIPANTS

Patients undergoing elective, isolated CABG.

INTERVENTIONS

Patients were randomized to receive a volatile anesthetic (desflurane, isoflurane, or sevoflurane) or total intravenous anesthesia (TIVA). The primary outcome was hemodynamically relevant MI (MI requiring high-dose inotropic support or prolonged intensive care unit stay) occurring within 48 hours from surgery. The secondary outcome was 1-year death due to cardiac causes.

MEASUREMENTS AND MAIN RESULTS

A total of 5,400 patients were enrolled between April 2014 and September 2017 (2,709 patients randomized to the volatile anesthetics group and 2,691 to TIVA). The mean age was 62 ± 8.4 years, and the median baseline ejection fraction was 57% (50-67), without differences between the 2 groups. Patients in the volatile group had a lower incidence of MI with hemodynamic complications both in the per-protocol (14 of 2,530 [0.6%] v 27 of 2,501 [1.1%] in the TIVA group; p = 0.038) and as-treated analyses (16 of 2,708 [0.6%] v 29 of 2,617 [1.1%] in the TIVA group; p = 0.039), but not in the intention-to-treat analysis (17 of 2,663 [0.6%] v 28 of 2,667 [1.0%] in the TIVA group; p = 0.10). Overall, deaths due to cardiac causes were lower in the volatile group (23 of 2,685 [0.9%] v 40 of 2,668 [1.5%] than in the TIVA group; p = 0.03).

CONCLUSIONS

An anesthetic regimen, including volatile agents, may be associated with a lower rate of postoperative MI with hemodynamic complication in patients undergoing CABG. Furthermore, it may reduce long-term cardiac mortality.

Non-invasive Assessment of Intravascular Volume Status for Postoperative Patients: The Correlation Between the Internal Jugular Vein/Common Carotid Artery Cross-sectional Area Ratio and the Inferior Vena Cava Diameter

Background

This study aimed to assess the correlation between the internal jugular vein/common carotid artery (IJV/CCA) cross-sectional area (CSA) ratio and the inferior vena cava (IVC) diameter as non-invasive techniques for the assessment of intravascular volume.

Methods

The study samples included 35 adult patients of both sexes (age range: 20 - 60 years) according to the criteria of the American Society of Anaesthesiology (ASA) physical status II - III, who were admitted to the surgical intensive care unit (SICU) after major surgeries for the assessment of intravascular volume status.

Results

There was a positive correlation between the IJV/CCA CSA ratio and the IVC maximum and minimum diameter before and after fluid infusion (r = 0.923, P < 0.001 and r = 0.390, P = 0.021, respectively) and between the IJV/CCA CSA ratio at inspiration and the IVC minimum diameter before and after fluid infusion (r = 0.605, P < 0.001 and r = 0.496, P < 0.001, respectively). The sensitivity and specificity analysis of the IJV/CCA CSA during inspiration after fluid correction to predict a central venous pressure (CVP) of 8 - 12 cmH₂O showed that at a ratio of 2.56, the highest sensitivity was 56.5%, and the specificity was 83.3%; at a ratio of 2.58, the highest sensitivity was 65.2% and the specificity was 75%. During expiration, at a ratio of 2.62, the highest sensitivity was 52.2%, and the specificity was 67%; and at a ratio of 2.65, the sensitivity was 56.5%, and the specificity was 50%.

Conclusions

The assessment of the IJV/CCA CSA ratio using bedside ultrasound could be a non-invasive tool for the evaluation of intravascular volume status in spontaneously breathing adult patients after major surgeries.

Use of Vasoactive Medications after Cardiac Surgery in the United States

Rationale: Patients undergoing cardiac surgery often require vasopressor or inotropic ("vasoactive") medications, but patterns of postoperative use are not well described.Objectives: This study aimed to describe vasoactive medication administration throughout hospitalization for cardiac surgery, to identify patient- and hospital-level factors associated with postoperative use, and to quantify variation in treatment patterns among hospitals.Methods: Retrospective study using the Premier Healthcare Database. The cohort included adult patients who underwent coronary artery bypass grafting or open valve repair or replacement (or in combination) from January 1, 2016, to June 30, 2018. Primary outcome was receipt of vasoactive medication(s) on the first postoperative day (POD1). We identified patient- and hospital-level factors associated with receipt of vasoactive medications using multilevel mixed-effects logistic regression modeling. We calculated adjusted median odds ratios to determine the extent to which receipt of vasoactive medications on POD1 was determined by each hospital, then calculated quotients of Akaike Information Criteria to compare the relative contributions of patient and hospital characteristics and individual hospitals with observed variation.Results: Among 104,963 adults in 294 hospitals, 95,992 (92.2%) received vasoactive medication(s) during hospitalization; 30,851 (29.7%) received treatment on POD1, most commonly norepinephrine (n = 11,427, 37.0%). A median of 29.0% (range, 0.0-94.4%) of patients in each hospital received vasoactive drug(s) on POD1. After adjustment, hospital of admission was associated with twofold increased odds of receipt of any vasoactive medication on POD1 (adjusted median odds ratio, 2.07; 95% confidence interval, 1.93-2.21). Admitting hospital contributed more to observed variation in POD1 vasoactive medication use than patient or hospital characteristics (quotients of Akaike Information Criteria 0.58, 0.44, and <0.001, respectively).Conclusions: Nearly all cardiac surgical patients receive vasoactive medications during hospitalization; however, only one-third receive treatment on POD1, with significant variability by institution. Further research is needed to understand the causes of variability across hospitals and whether these differences are associated with outcomes.

Can Inferior Vena Cava Diameter and Collapsibility Index Be a Predictor in Detecting Preoperative Intravascular Volume Change in Pediatric Patients?

Background: Inferior vena cava (IVC) ultrasound measurement is a reliable indicator used in the assessment of intravascular volume status. The aim of this study was to evaluate intravascular volume changes in pediatric patients by measuring the IVC diameter and collapsibility index (CI) in children whose oral feeding was restricted preoperatively. Material and Methods: From May 2018 to October 2018, a total of 55 pediatric patients who were scheduled for surgery were included in this prospective, observational, cohort study. Fasting and satiety IVC diameters and CIs of patients were determined by ultrasonographic evaluation twice: in the preoperative preliminary evaluation, when the patients were satiated, and before surgery, during a fasting period of 6–8 hours. Ultra-sonographic data were recorded and compared between fasting and satiety periods. Results: In the grey scale (B-mode), mean IVC diameter was significantly higher when the patients were satiated, compared to the measurements made just before surgery during the fasting period. In the M-mode, the mean IVC diameter was significantly higher only during the inspiratory phase when the patients were satiated, while during the expiratory phase it was detected to be statistically similar. Mean CI was significantly higher in the immediate preoperative period, compared to the assessment made when satiated. Conclusion: Preoperative ultrasound IVC diameter and CI measurement can be a practical and useful method for evaluating preoperative intravascular volume in children.

A Descriptive Study of Perioperative Hemodynamics in Open Cardiac Surgery Patients

OBJECTIVES

The purpose of the present study was to describe how the perioperative hemodynamic profile before and after cardiopulmonary bypass during cardiac surgery is influenced by age and to describe the association between postoperative hemodynamics and one-year mortality.

DESIGN

A retrospective registry-based study.

SETTING

University Hospital of Aarhus, Denmark.

PARTICIPANTS

The study comprised 6,595 patients undergoing elective on-pump cardiac surgery from 2006 to 2016.

MEASUREMENTS AND MAIN RESULTS

Perioperative hemodynamic values were derived from computerized anesthesia and intensive care reports, including mean arterial pressure, cardiac index, and oxygenation saturation from mixed venous blood in the pulmonary artery, during the perioperative period. Perioperative hemodynamic values were stratified according to age. Logistic regression was applied to predict the crude probability of death within one year from surgery according to hemodynamic values at six hours after surgery, stratified by age and use of inotropic agents, respectively. Lower values for cardiac index and mixed venous blood in the pulmonary artery with increasing age, across all points in time in the perioperative course, were observed. Higher probability of death was associated with lower hemodynamic values in the postoperative phase, and the probability of death was modified by age and the need for inotropic agents.

DISCUSSION

This is a large registry based study describing the perioperative hemodynamic profile of patients undergoing cardiac surgery and the results enhance our understanding of age-differentiated values of CI and SvO2 in this specific population.

The Relation Between Common Carotid Artery Diameter and Central Venous Pressure for Assessment of Intravascular Fluid Status after Major Surgeries; an Observational Study

Objectives

The current study aimed to find the relation between the changes in the common carotid artery (CCA) diameter and the central venous pressure (CVP) in response to a fluid challenge in spontaneously breathing adult patients.

Methods

This study included 65 adult patients aged 20 - 60 years who were admitted to the surgical ICU. The CCA diameter and CVP were measured before and after fluid challenge, and the percentage of increase in the CCA diameter and CVP were calculated. The correlation was assessed between changes in the CVP and CCA diameter.

Results

The CCA diameter before fluid administration had a significant strong positive correlation to the CVP (r = 0.8, P value < 0.001); the increase in the CCA diameter after fluid administration had a significant moderate positive correlation with the increase in the CVP (r = 0.4, P value < 0.001). The percentage of increase in CCA diameters was positively correlated to the percentage of increase in CVP (r = 0.589, P value = 0.001) following fluid administration. However, the Receiver Operating Characteristic (ROC) analysis was an invalid test (area under curve 0.513, P value = 0.885).

Conclusions

After major surgeries, the change in the CCA diameter was positively correlated with the change in the CVP values in response to fluid administration in the spontaneously breathing adult patients, but the cut-off limit cannot be reached.

The Septic Patient

Anesthesiologists are uniquely positioned to facilitate emergent care of patients with sepsis in the perioperative setting. A subset of sepsis patients presents with surgical pathology. Emphasis is on timely intervention with source control, antibiotic therapy, and aggressive resuscitation. Ileus, aspiration, and cardiovascular collapse must be considered when inducing patients with sepsis. Dynamic fluid responsiveness may prove an effective tool in minimizing over-resuscitation. Assessment of circulatory failure and drug therapy involves an understanding of preload, afterload, and contractility. Timely, targeted resuscitation and early source control have persisted and remain fundamental to sepsis care.

[Perioperative pharmacological circulatory support in daily clinical routine]

Perioperative phases of hypotension are associated with an increase in postoperative complications and organ damage. Whereas some years ago hemodynamic stabilization was primarily carried out by volume supplementation, in recent years the use and dosing of cardiovascular-active substances has significantly increased. But like intravascular volume therapy, also substances with a cardiovascular effect have therapeutic margins, and thus, potential side effects. This review article discusses indications for each cardiovascular-active agent, weighing up advantages and disadvantages. Special attention is paid to the question how to administrate them: central venous catheter vs. peripheral indwelling venous cannula. The authors come to the conclusion that it is not a question of whether it is principally allowed to apply cardiovascular-active drugs via peripheral veins but more importantly, what should be taken into consideration if a peripheral venous access is used. This article provides concise recommendations.

Retrospective analysis of central venous catheters in elective intracranial surgery - Is there any benefit?

Background

It remains unclear whether the use of central venous catheters (CVC) improves a patient's clinical outcome after elective intracranial supratentorial procedures.

Methods

This two-armed, single-center retrospective study sought to compare patients undergoing elective intracranial surgery with and without CVCs. Standard anaesthesia procedures were modified during the study period resulting in the termination of obligatory CVC instrumentation for supratentorial procedures. Peri-operative adverse events (AEs) were evaluated as primary endpoint.

Results

The data of 621 patients in total was analysed in this study (301 with and 320 without CVC). Patient characteristics and surgical procedures were comparable between both study groups. A total of 132 peri-operative AEs (81 in the group with CVC vs. 51 in the group without CVC) regarding neurological, neurosurgical, cardiovascular events and death were observed. CVC patients suffer from AEs almost twice as often as non CVC patients (OR_adjusted = 1.98; 95%CI[1.28–3.06]; p = 0.002). Complications related to catheter placement (pneumothorax and arterial malpuncture) were observed in 1.0% of the cases. The ICU treatment period in patients with CVC was 22 (19;24) vs. 21 (19;24) hours (p = 0.413). The duration of hospital stay was also similar between groups (9 (7;13) vs. 8 (7;11) days, p = 0.210). The total time of ventilation (350 (300;440) vs. 335 (281;405) min, p = 0.003) and induction time (40 (35;50) vs. 30 (25;35) min, p<0.001) was found to be prolonged significantly in the group with CVCs. There were no differences found in post-operative inflammatory markers as well as antibiotic treatment.

Conclusion

The data of our retrospective study suggests that patients undergoing elective neurosurgical procedures with CVCs do not demonstrate any additional benefits in comparison to patients without a CVC.

Preservation of renal function in cardiac surgery patients with low cardiac output syndrome: levosimendan vs beta agonists

BACKGROUND

Some studies have been performed to assess the effects of levosimendan on cardiac function when administered to cardiac surgery patients with low cardiac output syndrome (LCOS) in the immediate postoperative period. Levosimendan is an inotropic agent for the treatment of low cardiac output syndrome that seems to have a protective effect on renal function.

METHODS

It is a quasi-experimental study. A total of 100 patients with LCOS received either beta-agonists or levosimendan. We assessed the incidence of postoperative kidney failure in cardiac surgery patients. In patients who had kidney failure at diagnosis of LCOS, we examined whether differences existed in the evolution of kidney failure based on the treatment administered for LCOS. The parameters measured included haemodynamics, oxygen supply, and renal function as assessed by the AKI scale. ANOVA, Student's t-test and Wilcoxon or Friedman tests were used.

RESULTS

Up to 30% of cardiac surgery patients had kidney failure at diagnosis of LCOS. Kidney failure at discharge from the ICU was more frequent in patients who received beta-agonist drugs as compared to those who received levosimendan (p < 0.05).

CONCLUSION

The incidence of kidney failure decreased with the postoperative administration of levosimendan to cardiac surgery patients with LCOS, as compared to beta-agonists.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN 46058317. Date of registration: 7/10/2019. Retrospectively registered.

The expanding role of implantable devices to monitor heart failure and pulmonary hypertension

The epidemics of heart failure and, to a lesser extent, of pulmonary arterial hypertension continue unabated worldwide and are extremely costly in terms of loss of life and earnings, as well as the burden of health-care expenditure due to repeated hospitalization. The effectiveness of newly discovered therapies for the two conditions depends on their timely application. To date, symptoms have been used to guide the application and timing of therapy. Compelling evidence now exists that symptoms are preceded by several metabolic and haemodynamic changes, particularly a rise in intravascular pressures during exercise. These observations have stimulated the development of several implantable devices for the detection of impending unstable heart failure or pulmonary arterial hypertension, necessitating admission to hospital. In this Review, we summarize the rationale for monitoring patients with heart failure or pulmonary arterial hypertension, the transition from noninvasive to implantable devices and the current and anticipated clinical uses of these devices.

Pulse Pressure Variation-Guided Fluid Therapy during Supratentorial Brain Tumour Excision: A Randomized Controlled Trial

BACKGROUND:

Goal-directed fluid therapy (GDFT) improved patient outcomes in various surgical procedures; however, its role during mass brain resection was not well investigated.

AIM:

In this study, we evaluated a simple protocol based on intermittent evaluation of pulse pressure variation for guiding fluid therapy during brain tumour resection.

METHODS:

Sixty-one adult patients scheduled for supratentorial brain mass excision were randomized into either GDFT group (received intraoperative fluids guided by pulse pressure variation) and control group (received standard care). Both groups were compared according to the following: brain relaxation scale (BRS), mean arterial pressure, heart rate, urine output, intraoperative fluid intake, postoperative serum lactate, and length of hospital stay.

RESULTS:

Demographic data, cardiovascular data (mean arterial pressure and heart rate), and BRS were comparable between both groups. GDFT group received more intraoperative fluids {3155 (452) mL vs 2790 (443) mL, P = 0.002}, had higher urine output {2019 (449) mL vs 1410 (382) mL, P < 0.001}, and had lower serum lactate {0.9 (1) mmol versus 2.5 (1.1) mmol, P = 0.03} compared to control group.

CONCLUSION:

In conclusion, PPV-guided fluid therapy during supratentorial mass excision, increased intraoperative fluids, and improved peripheral perfusion without increasing brain swelling.

Cardiopulmonary Bypass in Premature and Low Birth Weight Neonates - Implications for Postoperative Care From a Neonatologist/Intensivist Perspective

Prematurity and low weight remain significant risk factors for mortality after neonatal cardiac surgery despite steady gains in survival. Newer and lower weight thresholds for operability are constantly generated as surgeons gather proficiency, technical mastery, and experience in performing complex procedures on extremely small infants. Relationship between birth weight and survival after cardiac surgery is nonlinear with 2 kg being an inflection point below which marked decline in survival occurs. If strides toward improved survival in this weight category are to be made, understanding the inherent vulnerabilities of the premature and low birth weight infant is important in addition to acknowledging the vulnerabilities of the system in which care is delivered.

Blood pressure waveform contour analysis for assessing peripheral resistance changes in sepsis

BACKGROUND

This paper proposes a methodology for helping bridge the gap between the complex waveform information frequently available in an intensive care unit and the simple, lumped values favoured for rapid clinical diagnosis and management. This methodology employs a simple waveform contour analysis approach to compare aortic, femoral and central venous pressure waveforms on a beat-by-beat basis and extract lumped metrics pertaining to the pressure drop and pressure-pulse amplitude attenuation as blood passes through the various sections of systemic circulation.

RESULTS

Validation encompasses a comparison between novel metrics and well-known, analogous clinical metrics such as mean arterial and venous pressures, across an animal model of induced sepsis. The novel metric Ofe → vc, the direct pressure offset between the femoral artery and vena cava, and the clinical metric, ΔMP, the difference between mean arterial and venous pressure, performed well. However, Ofe → vc reduced the optimal average time to sepsis detection after endotoxin infusion from 46.2 min for ΔMP to 11.6 min, for a slight increase in false positive rate from 1.8 to 6.2%. Thus, the novel Ofe → vc provided the best combination of specificity and sensitivity, assuming an equal weighting to both, of the metrics assessed.

CONCLUSIONS

Overall, the potential of these novel metrics in the detection of diagnostic shifts in physiological behaviour, here driven by sepsis, is demonstrated.

Postoperative management of patients undergoing cardiac surgery in Austria : A national survey on current clinical practice in hemodynamic monitoring and postoperative management

Background

No data are currently available regarding the current clinical practice in postoperative care of cardiac surgical patients in Austria.

Objective

The study investigated the current intensive care management concerning hemodynamic monitoring and strategies to treat common perioperative disorders of patients after cardiac surgery in Austria.

Methods

A survey consisting of 31 questions was sent to intensivists at all 9 hospitals offering cardiac surgery in Austria.

Results

The response rate was 100%. The mean number of procedures on cardiopulmonary bypass per centre was 722 ± 223. In the majority of cases postoperative critical care is performed by anesthesiologists. Blood gas analysis, pulse oximetry, electrocardiogram, temperature, central venous pressure, arterial pressure and hourly urine output are de facto standard monitoring in all centers. Transesophageal echocardiography is available in all centers and is frequently used. Crystalloids are the first choice for volume replacement, whereas levosimendan and adrenaline are employed for the treatment of low cardiac output syndrome.

Conclusions

This study provides insights into the current state of postoperative management of cardiac surgical patients in Austria. Standard monitoring as proposed by international guidelines is well established in Austrian intensive care units. Echocardiography is widely seen as a very important tool in the postoperative care of cardiac surgical patients. Knowledge about the status quo of postoperative intensive care management of cardiac surgical patients enables further development of patient care.

Electronic supplementary material

The online version of this article (10.1007/s00508-018-1403-3) contains supplementary material, which is available to authorized users.

Utilization of echocardiography in Intensive Care Units: results of an online survey in Germany

BACKGROUND

In patients with hemodynamic instability echocardiography has been recommended as the preferred modality to evaluate the underlying pathophysiology. However, due to the fact that recent scientific data on the utilization of echocardiography in German Intensive Care Units (ICU) are scarce, we sought to investigate current practice.

METHODS

A structured, web-based, anonymized survey was performed from May until July 2015 among members of the German Interdisciplinary Association of Critical Care and Emergency Medicine (DIVI) consisting of 14 questions. Descriptive data analysis was performed.

RESULTS

One hundred four intensivists participated in the survey. Two-thirds of participants (66%) used echocardiography regularly for hemodynamic monitoring and stated that it changed the therapy in 26-50% of the cases irrespective of the time performed after ordering the examination. Transthoracic (TTE) were more frequently used than transesophageal (TEE) examinations. Twenty-six percent of the participants held an echocardiography certificate with a formal examination, 27% completed a structured training without an examination and almost half of the questioned ICU personnel (47%) did not complete a comprehensive training.

CONCLUSIONS

The results of this survey demonstrate a widespread utilization of echocardiography as part of routine diagnostic on frequent number of operative ICUs. However, there might be a lack of structured echocardiographic training especially for anesthesiologists.

Measurement of Internal Jugular Vein and Common Carotid Artery Diameter Ratio by Ultrasound to Estimate Central Venous Pressure

Objective

The objective of this study is to find a correlation between internal jugular vein (IJV) and common carotid artery (CCA) diameter ratio and central venous pressure (CVP) measurement and find a cut-off value for the IJV/CCA ratio to predict low CVP i.e. < 10 cm H₂0, for estimating the volume status in critically ill patients.

Methods

This prospective cross-sectional study was conducted at the critical care department of Shifa International Hospital, Islamabad, from July to December 2017. A sample of 49 patients ≥ 18 years with intrathoracic central venous catheters (CVCs) who underwent bedside sonographic assessments of IJV and CCA diameter were included in this study using convenient sampling. The IJV/CCA diameter ratio was calculated and correlated with CVP and the predictive value of the IJV/CCA diameter ratio to predict CVP < 10 cm H₂O was explored by calculating the area under the receiver operating characteristic (ROC) curve, sensitivity, specificity, and positive and negative predictive values.

Results

A total of 49 patients, 30 males (61.2%) and 19 females (38.8%) with a mean age of 56.00±16.11 years were included in the study. The mean CVP was 8.98±2.37cm H₂O in ventilated (51%) and 10.7± 6.01 cm H₂O in non-ventilated (49%) patients. The mean IJV/CCA diameter ratio was 1.60±0.55 at expiration and 1.41±0.56 at inspiration. There was a significant correlation between the IJV/CCA diameter ratio and CVP at expiration (r=0.401, p=0.004). The correlation between IJV/CCA and CVP was significant in non-ventilated patients at expiration (r=0.439, p=0.032). The area under the ROC curve for the IJV/CCA diameter ratio for predicting CVP < 10 cm H₂O was 0.684 (p=0.028). The predictive value of the IJV/CCA diameter ratio for CVP < 10 cm H₂0 at the cutoff value of < 2 was insignificant. A new cut-off < 1.75 was taken for the IJV/CCA diameter ratio from the coordinates of the ROC curve. The sensitivity, specificity, PPV, and NPV of an IJV/CCA diameter ratio of < 1.75 for predicting a CVP < 10 cm H₂0 were 84.62%, 52.17%, 66.67%, and 75.00%, respectively.

Conclusion

The assessment of volume status by the IJV/CCA diameter ratio with a sonographic device may be a useful noninvasive alternative for a central venous catheterization with a cut-off < 1.75.

Beat-by-Beat Estimation of the Left Ventricular Pressure-Volume Loop Under Clinical Conditions

This paper develops a method for the minimally invasive, beat-by-beat estimation of the left ventricular pressure-volume loop. This method estimates the left ventricular pressure and volume waveforms that make up the pressure-volume loop using clinically available inputs supported by a short, baseline echocardiography reading. Validation was performed across 142,169 heartbeats of data from 11 Piétrain pigs subject to two distinct protocols encompassing sepsis, dobutamine administration and clinical interventions. The method effectively located pressure-volume loops, with low overall median errors in end-diastolic volume of 8.6%, end-systolic volume of 17.3%, systolic pressure of 19.4% and diastolic pressure of 6.5%. The method further demonstrated a low overall mean error of 23.2% predicting resulting stroke work, and high correlation coefficients along with a high percentage of trend compass 'in band' performance tracking changes in stroke work as patient condition varied. This set of results forms a body of evidence for the potential clinical utility of the method. While further validation in humans is required, the method has the potential to aid in clinical decision making across a range of clinical interventions and disease state disturbances by providing real-time, beat-to-beat, patient specific information at the intensive care unit bedside without requiring additional invasive instrumentation.

Minimally invasive, patient specific, beat-by-beat estimation of left ventricular time varying elastance

Background

The aim of this paper was to establish a minimally invasive method for deriving the left ventricular time varying elastance (TVE) curve beat-by-beat, the monitoring of which’s inter-beat evolution could add significant new data and insight to improve diagnosis and treatment. The method developed uses the clinically available inputs of aortic pressure, heart rate and baseline end-systolic volume (via echocardiography) to determine the outputs of left ventricular pressure, volume and dead space volume, and thus the TVE curve. This approach avoids directly assuming the shape of the TVE curve, allowing more effective capture of intra- and inter-patient variability.

Results

The resulting TVE curve was experimentally validated against the TVE curve as derived from experimentally measured left ventricular pressure and volume in animal models, a data set encompassing 46,318 heartbeats across 5 Piétrain pigs. This simulated TVE curve was able to effectively approximate the measured TVE curve, with an overall median absolute error of 11.4% and overall median signed error of −2.5%.

Conclusions

The use of clinically available inputs means there is potential for real-time implementation of the method at the patient bedside. Thus the method could be used to provide additional, patient specific information on intra- and inter-beat variation in heart function.

Electronic supplementary material

The online version of this article (doi:10.1186/s12938-017-0338-7) contains supplementary material, which is available to authorized users.

Correlation of IVC Diameter and Collapsibility Index With Central Venous Pressure in the Assessment of Intravascular Volume in Critically Ill Patients

Objective

The objective of our study is to assess the correlation between inferior vena cava (IVC) diameters, central venous pressure (CVP) and the IVC collapsibility index for estimating the volume status in critically ill patients.

Methods

This cross-sectional study used the convenient sampling of 100 adult medical intensive care unit (ICU) patients for a period of three months. Patients ≥ 18 years of age with an intrathoracic central venous catheter terminating in the distal superior vena cava connected to the transducer to produce a CVP waveform were included in the study. A Mindray diagnostic ultrasound system model Z6 ultrasound machine (Mindray, NJ, USA) was used for all examinations. An Ultrasonic Transducer model 3C5P (Mindray, NJ, USA) for IVC imaging was utilized. A paired sampled t-test was used to compute the p-values.

Results

A total of 32/100 (32%) females and 68/100 (68%) males were included in the study with a mean age of 50.4 ± 19.3 years. The mean central venous pressure maintained was 10.38 ± 4.14 cmH2O with an inferior vena cava collapsibility index of 30.68 ± 10.93. There was a statistically significant relation among the mean CVP pressure, the IVC collapsibility index, the mean maximum and minimum IVC between groups as determined by one-way analysis of variance (ANOVA) (p < 0.001). There was a strong negative correlation between CVP and IVC collapsibility index (%), which was statistically significant (r = -0.827, n = 100, p < 0.0005). A strong positive correlation between CVP and maximum IVC diameter (r = 0.371, n = 100, p < 0.0005) and minimum IVC diameter (r = 0.572, n = 100, p < 0.0005) was found.

Conclusion

There is a positive relationship of CVP with minimum and maximum IVC diameters but an inverse relationship with the IVC collapsibility index.

Vasoactive Drugs and Hemodynamic Monitoring in Pediatric Cardiac Intensive Care: An Italian Survey

BACKGROUND

Little is known about practitioner preference, the availability of technology, and variability in practice with respect to hemodynamic monitoring and vasoactive drug use after congenital heart surgery. The aim of this study was to characterize current hospital practices related to the management of low cardiac output syndrome (LCOS) across Italy.

METHODS

We issued a 22-item questionnaire to 14 Italian hospitals performing pediatric cardiac surgery.

RESULTS

Electrocardiogram, invasive blood pressure, central venous pressure, pulse oximetry, diuresis, body temperature, arterial lactate, and blood gas analysis were identified as routine in hemodynamic monitoring. With regard to advanced hemodynamic monitoring, pulmonary arterial catheter and transpulmonary thermodilution were available in 43% of the centers, uncalibrated pulse contour methods in 29% of the centers, and transesophageal/transthoracic echocardiograms in all of the centers. Dopamine added to milrinone was the most frequent drug regimen for LCOS prevention after cardiopulmonary bypass. Overall, 86% of centers used milrinone alone as the initial treatment for LCOS with elevated systemic vascular resistances and levosimendan, the second preferred choice. In cases of LCOS with low vascular resistance, epinephrine was the first choice (10 centers), dopamine was the second choice (4 centers), followed by vasopressin and norepinephrine (3 centers). For treatment of LCOS with elevated pulmonary resistances, milrinone was the first choice (eight centers), followed by inhaled nitric oxide (five centers).

CONCLUSIONS

The survey shows that advanced hemodynamic monitoring is rarely performed. The most commonly used vasoactive drugs are milrinone, levosimendan, dopamine, epinephrine, vasopressin, and norepinephrine. Guidelines on the topic are warranted.

Practice of hemodynamic monitoring and management in German, Austrian, and Swiss intensive care units: the multicenter cross-sectional ICU-CardioMan Study

BACKGROUND

Hemodynamic instability is frequent and outcome-relevant in critical illness. The understanding of complex hemodynamic disturbances and their monitoring and management plays an important role in treatment of intensive care patients. An increasing number of treatment recommendations and guidelines in intensive care medicine emphasize hemodynamic goals, which go beyond the measurement of blood pressures. Yet, it is not known to which extent the infrastructural prerequisites for extended hemodynamic monitoring are given in intensive care units (ICUs) and how hemodynamic management is performed in clinical practice. Further, it is still unclear which factors trigger the use of extended hemodynamic monitoring.

METHODS

In this multicenter, 1-day (November 7, 2013, and the preceding 24 h) cross-sectional study, we retrieved data on patient monitoring from ICUs in Germany, Austria, and Switzerland by means of a web-based case report form. One hundred and sixty-one intensive care units contributed detailed information on availability of hemodynamic monitoring. In addition, detailed information on hemodynamic monitoring of 1789 patients that were treated on due date was collected, and independent factors triggering the use of extended hemodynamic monitoring were identified by multivariate analysis.

RESULTS

Besides basic monitoring with electrocardiography (ECG), pulse oximetry, and blood pressure monitoring, the majority of patients received invasive arterial (77.9 %) and central venous catheterization (55.2 %). All over, additional extended hemodynamic monitoring for assessment of cardiac output was only performed in 12.3 % of patients, while echocardiographic examination was used in only 1.9 %. The strongest independent predictors for the use of extended hemodynamic monitoring of any kind were mechanical ventilation, the need for catecholamine therapy, and treatment backed by protocols. In 71.6 % of patients in whom extended hemodynamic monitoring was added during the study period, this extension led to changes in treatment.

CONCLUSIONS

Extended hemodynamic monitoring, which goes beyond the measurement of blood pressures, to date plays a minor role in the surveillance of critically ill patients in German, Austrian, and Swiss ICUs. This includes also consensus-based recommended diagnostic and monitoring applications, such as echocardiography and cardiac output monitoring. Mechanical ventilation, the use of catecholamines, and treatment backed by protocol could be identified as factors independently associated with higher use of extended hemodynamic monitoring.

Intra-Operative Fluid Management in Adult Neurosurgical Patients Undergoing Intracranial Tumour Surgery: Randomised Control Trial Comparing Pulse Pressure Variance (PPV) and Central Venous Pressure (CVP)

INTRODUCTION

Fluid management in neurosurgery presents specific challenges to the anaesthesiologist. Dynamic para-meters like Pulse Pressure Variation (PPV) have been used successfully to guide fluid management.

AIM

To compare PPV against Central Venous Pressure (CVP) in neurosurgical patients to assess hemodynamic stability and perfusion status.

MATERIALS AND METHODS

This was a single centre prospective randomised control trial at a tertiary care centre. A total of 60 patients undergoing intracranial tumour excision in supine and lateral positions were randomised to two groups (Group 1, CVP n=30), (Group 2, PPV n=30). Intra-operative fluid management was titrated to maintain baseline CVP in Group 1(5-10cm of water) and in Group 2 fluids were given to maintain PPV less than 13%. Acid base status, vital signs and blood loss were monitored.

RESULTS

Although intra-operative hypotension and acid base changes were comparable between the groups, the patients in the CVP group had more episodes of hypotension requiring fluid boluses in the first 24 hours post surgery. {CVP group median (25, 75) 2400ml (1850, 3110) versus PPV group 2100ml (1350, 2200) p=0.03} The patients in the PPV group received more fluids than the CVP group which was clinically significant. {2250 ml (1500, 3000) versus 1500ml (1200, 2000) median (25, 75) (p=0.002)}. The blood loss was not significantly different between the groups The median blood loss in the CVP group was 600ml and in the PPV group was 850 ml; p value 0.09.

CONCLUSION

PPV can be used as a reliable index to guide fluid management in neurosurgical patients undergoing tumour excision surgery in supine and lateral positions and can effectively augment CVP as a guide to fluid management. Patients in PPV group had better hemodynamic stability and less post operative fluid requirement.

Interventions That Affect Gastrointestinal Motility in Hospitalized Adult Patients: A Systematic Review and Meta-Analysis of Double-Blind Placebo-Controlled Randomized Trials

Gastrointestinal (GI) dysmotility is a common complication in acute, critically ill, postoperative, and chronic patients that may lead to impaired nutrient delivery, poor clinical, and patient-reported outcomes. Several pharmacological and nonpharmacological interventions to treat GI dysmotility were investigated in dozens of clinical studies. However, they often yielded conflicting results, at least in part, because various (nonstandardized) definitions of GI dysmotility were used and methodological quality of studies was poor. While a universally accepted definition of GI dysmotility is yet to be developed, a systematic analysis of data derived from double-blind placebo-controlled randomized trials may provide robust data on absolute and relative effectiveness of various interventions as the study outcome (GI motility) was assessed in the least biased manner.To systematically review data from double-blind placebo-controlled randomized trials to determine and compare the effectiveness of interventions that affect GI motility.Three electronic databases (MEDLINE, SCOPUS, and EMBASE) were searched. A random effects model was used for meta-analysis. The summary estimates were reported as mean difference (MD) with the corresponding 95% confidence interval (CI).A total of 38 double-blind placebo-controlled randomized trials involving 2371 patients were eligible for inclusion in the systematic review. These studies investigated a total of 20 different interventions, of which 6 interventions were meta-analyzed. Of them, the use of dopamine receptor antagonists (MD, -8.99; 95% CI, -17.72 to -0.27; P = 0.04) and macrolides (MD, -26.04; 95% CI, -51.25 to -0.82; P = 0.04) significantly improved GI motility compared with the placebo group. The use of botulism toxin significantly impaired GI motility compared with the placebo group (MD, 5.31; 95% CI, -0.04 to 10.67; P = 0.05). Other interventions (dietary factors, probiotics, hormones) did not affect GI motility.Based on the best available data and taking into account the safety profile of each class of intervention, dopamine receptor antagonists and macrolides significantly improve GI motility and are medications of choice in treating GI dysmotility.

Cost-benefits of incorporating levosimendan into cardiac surgery practice: German base case

OBJECTIVE

To evaluate the cost-benefit of using levosimendan compared with dobutamine, in the perioperative treatment of patients undergoing cardiac surgery who require inotropic support.

METHODS

A two-part Markov model was designed to simulate health-state transitions of patients undergoing cardiac surgery, and estimate the short- and long-term health benefits of treatment. Hospital length of stay (LOS), mortality, medication, and adverse events were key clinical- and cost-inputs. Cost-benefits were evaluated in terms of costs and bed stays within the German healthcare system. Drug prices were calculated from the German Drug Directory (€/2014) and published literature, with a 3% annual discount rate applied. The base case analysis was for a 1-year time horizon.

RESULTS

The use of levosimendan vs dobutamine was associated with cost savings of €4787 per patient from the German hospital perspective due to reduced adverse events and shorter hospital LOS, leading to increased bed capacity and hospital revenue.

LIMITATIONS

A pharmacoeconomic calculation for the specific situation of the German healthcare system that is based on international clinical trial carries a substantial risk of disregarding potentially relevant but unknown confounding factors (i.e., ICU-staffing, co-medications, standard-ICU care vs fast-tracking, etc.) that may either attenuate or increase the outcome pharmacoeconomic effects of a drug; however, since these conditions would also apply for patients treated with comparators, their net effects may not necessarily influence the conclusions.

CONCLUSIONS

The use of levosimendan in patients undergoing cardiac surgery who require inotropic support appears to be cost-saving. The results of the analysis provide a strong rationale to run local clinical studies with pharmacoeconomic end-points which would allow a much more precise computation of the benefits of levosimendan.

Tissue oxygen saturation as an early indicator of delayed lactate clearance after cardiac surgery: a prospective observational study

Background

In this observational study near infrared spectroscopy (NIRS) was evaluated as a non-invasive monitor of impaired tissue oxygenation (StO₂) after cardiac surgery. StO₂, cardiac output, mixed venous oxygen saturation and mean arterial pressure were compared with lactate clearance as established measure for sufficient tissue perfusion and oxygen metabolism.

Methods

Forty patients after cardiac surgery (24 aortocoronary bypass grafting, 5 heart valve, 3 ascending aorta and 8 combined procedures) were monitored until postoperative day 1 with NIRS of the thenar muscle (InSpectra™ StO₂-monitor, Hutchinson Technology), a pulmonary-artery catheter and intermittent blood gas analyses for the assessment of lactate clearance.

Results

StO₂ was reduced 4 h after surgery (75 ± 6 %), but recovered at day 1 (84 ± 5 %), while lactate concentration remained increased. Using uni- and multivariate regression analysis, minimum StO₂ (r = 0.46, p <0.01) and cardiac index (r = 0.40, p <0.05) correlated with lactate clearance at day 1, while minimum mixed venous saturation and mean arterial pressure did not. In a receiver-operating characteristics (ROC) analysis, minimum StO₂ (with a threshold of 75 %) predicted a lactate clearance <10 % at day 1 with an area under the ROC-curve of 0.83, a sensitivity of 78 % and a specificity of 88 %. In the subgroup with StO₂  <75 %, troponin and creatine kinase MB were significantly increased at day 1.

Conclusions

StO₂ below 75 % in the first hours after surgery was a better early indicator of persistent impaired lactate clearance at day 1 than cardiac index, mixed venous oxygen saturation or mean arterial pressure.

Extensive variability in vasoactive agent therapy: a nationwide survey in Chinese intensive care units

BACKGROUND

Inconsistencies in the use of the vasoactive agent therapy to treat shock are found in previous studies. A descriptive study was proposed to investigate current use of vasoactive agents for patients with shock in Chinese intensive care settings.

METHODS

A nationwide survey of physicians was conducted from August 17 to December 30, 2012. Physicians were asked to complete a questionnaire which focused on the selection of vasoactive agents, management in the use of vasopressor/inotropic therapy, monitoring protocols when using these agents, and demographic characteristics.

RESULTS

The response rate was 65.1% with physicians returning 586 valid questionnaires. Norepinephrine was the first choice of a vasopressor used to treat septic shock by 70.8% of respondents; 73.4% of respondents favored dopamine for hypovolemic shock; and 68.3% of respondents preferred dopamine for cardiogenic shock. Dobutamine was selected by 84.1%, 64.5%, and 60.6% of respondents for septic, hypovolemic, and cardiogenic shock, respectively. Vasodilator agents were prescribed by physicians in the management of cardiogenic shock (67.1%) rather than for septic (32.3%) and hypovolemic shock (6.5%). A significant number of physicians working in teaching hospitals were using vasoactive agents in an appropriate manner when compared to physicians in nonteaching hospitals.

CONCLUSIONS

Vasoactive agent use for treatment of shock is inconsistent according to self-report by Chinese intensive care physicians; however, the variation in use depends upon the form of shock being treated and the type of hospital; thus, corresponding educational programs about vasoactive agent use for shock management should be considered.

Postoperative Critical Care of the Adult Cardiac Surgical Patient. Part I: Routine Postoperative Care

OBJECTIVES

Cardiac surgery, including coronary artery bypass, cardiac valve, and aortic procedures, is among the most common surgical procedures performed in the United States. Successful outcomes after cardiac surgery depend on optimum postoperative critical care. The cardiac intensivist must have a comprehensive understanding of cardiopulmonary physiology and the sequelae of cardiopulmonary bypass. In this concise review, targeted at intensivists and surgeons, we discuss the routine management of the postoperative cardiac surgical patient.

DATA SOURCE AND SYNTHESIS

Narrative review of relevant English-language peer-reviewed medical literature.

CONCLUSIONS

Critical care of the cardiac surgical patient is a complex and dynamic endeavor. Adequate fluid resuscitation, appropriate inotropic support, attention to rewarming, and ventilator management are key components. Patient safety is enhanced by experienced personnel, a structured handover between the operating room and ICU teams, and appropriate transfusion strategies.

Postoperative fluid management

Postoperative care units are run by an anesthesiologist or a surgeon, or a team formed of both. Management of postoperative fluid therapy should be done considering both patients’ status and intraoperative events. Types of the fluids, amount of the fluid given and timing of the administration are the main topics that determine the fluid management strategy. The main goal of fluid resuscitation is to provide adequate tissue perfusion without harming the patient. The endothelial glycocalyx dysfunction and fluid shift to extracellular compartment should be considered wisely. Fluid management must be done based on patient’s body fluid status. Patients who are responsive to fluids can benefit from fluid resuscitation, whereas patients who are not fluid responsive are more likely to suffer complications of over-hydration. Therefore, common use of central venous pressure measurement, which is proved to be inefficient to predict fluid responsiveness, should be avoided. Goal directed strategy is the most rational approach to assess the patient and maintain optimum fluid balance. However, accessible and applicable monitoring tools for determining patient’s actual fluid need should be further studied and universalized. The debate around colloids and crystalloids should also be considered with goal directed therapies. Advantages and disadvantages of each solution must be evaluated with the patient’s specific condition.

Clinical practice in perioperative monitoring in adult cardiac surgery: is there a standard of care? Results from an national survey

This study was to investigate and define what is considered as a current clinical practice in hemodynamic monitoring and vasoactive medication use after cardiac surgery in Italy. A 33-item questionnaire was sent to all intensive care units (ICUs) admitting patients after cardiac surgery. 71 out of 92 identified centers (77.2 %) returned a completed questionnaire. Electrocardiogram, invasive blood pressure, central venous pressure, pulse oximetry, diuresis, body temperature and blood gas analysis were identified as routinely used hemodynamic monitoring, whereas advanced monitoring was performed with pulmonary artery catheter or echocardiography. Crystalloids were the fluids of choice for volume replacement (86.8 % of Centers). To guide volume management, central venous pressure (26.7 %) and invasive blood pressure (19.7 %) were the most frequently used parameters. Dobutamine was the first choice for treatment of left heart dysfunction (40 %) and epinephrine was the first choice for right heart dysfunction (26.8 %). Half of the Centers had an internal protocol for vasoactive drugs administration. Intra-aortic balloon pump and extra-corporeal membrane oxygenation were widely available among Cardiothoracic ICUs. Angiotensin-converting enzyme inhibitors were suspended in 28 % of the Centers. The survey shows what is considered as standard monitoring in Italian Cardiac ICUs. Standard, routinely used monitoring consists of ECG, SpO2, etCO2, invasive BP, CVP, diuresis, body temperature, and BGA. It also shows that there is large variability among the various Centers regarding hemodynamic monitoring of fluid therapy and inotropes administration. Further research is required to better standardize and define the indicators to improve the standards of intensive care after cardiac surgery among Italian cardiac ICUs.

Perioperative fluid therapy: a statement from the international Fluid Optimization Group

BACKGROUND

Perioperative fluid therapy remains a highly debated topic. Its purpose is to maintain or restore effective circulating blood volume during the immediate perioperative period. Maintaining effective circulating blood volume and pressure are key components of assuring adequate organ perfusion while avoiding the risks associated with either organ hypo- or hyperperfusion. Relative to perioperative fluid therapy, three inescapable conclusions exist: overhydration is bad, underhydration is bad, and what we assume about the fluid status of our patients may be incorrect. There is wide variability of practice, both between individuals and institutions. The aims of this paper are to clearly define the risks and benefits of fluid choices within the perioperative space, to describe current evidence-based methodologies for their administration, and ultimately to reduce the variability with which perioperative fluids are administered.

METHODS

Based on the abovementioned acknowledgements, a group of 72 researchers, well known within the field of fluid resuscitation, were invited, via email, to attend a meeting that was held in Chicago in 2011 to discuss perioperative fluid therapy. From the 72 invitees, 14 researchers representing 7 countries attended, and thus, the international Fluid Optimization Group (FOG) came into existence. These researches, working collaboratively, have reviewed the data from 162 different fluid resuscitation papers including both operative and intensive care unit populations. This manuscript is the result of 3 years of evidence-based, discussions, analysis, and synthesis of the currently known risks and benefits of individual fluids and the best methods for administering them.

RESULTS

The results of this review paper provide an overview of the components of an effective perioperative fluid administration plan and address both the physiologic principles and outcomes of fluid administration.

CONCLUSIONS

We recommend that both perioperative fluid choice and therapy be individualized. Patients should receive fluid therapy guided by predefined physiologic targets. Specifically, fluids should be administered when patients require augmentation of their perfusion and are also volume responsive. This paper provides a general approach to fluid therapy and practical recommendations.

Inferior Vena Cava Assessment: Correlation with CVP and Plethora in Tamponade

Bedside assessment of intravascular volume status plays an important role in the management of critically ill patients, guiding fluid replacement therapy and the use of vasopressor agents. Despite controversy in the existing evidence, many clinicians advocate the use of inferior vena cava ultrasound (IVC-US) in the assessment of intravascular volume status in critically ill patients. Respirophasic variation in IVC diameter may provide useful information regarding intravascular volume status, particularly in patients with high and low caval indices. However, due to conflicting results of small-scale clinical trials of divergent sample populations, there is insufficient evidence to support routine US assessment of the IVC to determine fluid responsiveness in spontaneous breathing with circulatory compromise. Additional large-scale clinical trials are required to determine the accuracy of IVC-US measurements in diverse populations and to ascertain the effects on IVC dimensions that result from cardiac dysfunction and intra-abdominal hypertension.

Bedside ultrasonographic measurement of the inferior vena cava fails to predict fluid responsiveness in the first 6 hours after cardiac surgery: a prospective case series observational study

OBJECTIVE

To assess validity of respiratory variation of inferior vena cava (IVC) diameter to predict fluid responsiveness and guide fluid therapy in mechanically ventilated patients during the first 6 hours after elective cardiac surgery.

DESIGN

Prospective observational case series study.

SETTING

Single-center hospital.

PATIENTS

50 consecutive patients undergoing elective cardiac surgery.

INTERVENTIONS

Transthoracic bedside echocardiography.

MEASUREMENTS AND MAIN RESULTS

Parameters derived from ultrasonographic assessment of the IVC diameter (collapsibility index [CI], distensibility index [DI], and IVC/aorta index). In the whole study group, change in fluid balance correlated with change in IVC maximum diameter (p = 0.034, r = 0.176). IVC-CI and IVC-DI correlated with IVC/aorta index. A weak correlation between central venous pressure (CVP) and IVC-derived parameters (IVC-CI and IVC-DI) was noticed. Despite statistical significance (p<0.05), all observed correlations expressed low statistical power (r<0.21). There were no statistically significant differences between fluid responders and nonresponders in relation to clinical parameters, CVP, ultrasound IVC measurement, and IVC-derived indices.

CONCLUSION

Dynamic IVC-derived parameters (IVC-CI, IVC-DI, and IVC/aorta index) and CVP are not reliable predictors of fluid responsiveness in the first 6 hours after cardiac surgery. Complexity of physiologic factors modulating cardiac performance in this group may be responsible for the difficulty in finding a plausible monitoring tool for fluid guidance. Bedside ultrasonographic measurement of IVC is unable to predict fluid responsiveness in the first 6 hours after cardiac surgery.

Fluid management in the cardiothoracic intensive care unit: diuresis--diuretics and hemofiltration

PURPOSE OF REVIEW

The present review discusses the current concepts of fluid management in cardiothoracic surgery, and its clinical implications with special reference to organ-related complications and their prevention.

RECENT FINDINGS

Current strategies in fluid management for cardiothoracic patients, various fluid formulation, and the preventive strategies for minimizing fluid-related complications are described, with particular reference to new discoveries and controversies that have arisen from recent literature.

SUMMARY

The optimal fluid management in cardiothoracic patients has not been settled. Results of recent clinical published trials highlight the need for minimizing fluid administration and attempting to use diuretics to achieve a negative fluid, although hypovolemia and hypoperfusion should be carefully considered. An individualized optimization of fluid status, using goal-directed therapy, has emerged as a possible preferable approach. The old debate between crystalloid and colloid solutions has been partially solved, as some colloids have demonstrated deleterious effect on renal function and coagulation system. Various preventive strategies have also emerged for minimizing fluid-related complications.

Catecholamine and volume therapy for cardiac surgery in Germany--results from a postal survey

BACKGROUND

Management of cardiac surgery patients is a very standardized procedure in respective local institutions. Yet only very limited evidence exists concerning optimal indication, safety and efficacy of hemodynamic monitoring catecholamine and fluid therapy.

METHODS

Between April and May 2013, all 81 German anaesthesia departments involved in cardiac surgery care were asked to participate in a questionnaire addressing the institutional specific current practice in hemodynamic monitoring, catecholamine and volume therapy.

RESULTS

51 (63%) questionnaires were completed and returned. All participating centers used basic hemodynamic monitoring (i.e. invasive arterial blood pressure and central venous pressure), supplemented by transesophageal echocardiography. Pulmonary arterial catheter and calibrated trend monitoring devices were also routinely available. In contrast, non-calibrated trend monitoring and esophageal doppler ultrasound devices were not commonly in use. Cerebral oximetry is increasingly emerging, but lacks clear indications. The majority of patients undergoing cardiac surgery, especially in university hospitals, required catecholamines during perioperative care, In case of low cardiac output syndrome, dobutamine (32%), epinephrine (30%) or phosphodiesterase inhibitors (8%) were first choice. In case of hypotension following vasoplegia, norepinephrine (96%) represented the most common catecholamine. 88% of the participating centers reported regular use of colloid fluids, with hydroxyethyl starches (HES) being first choice (64%).

CONCLUSIONS

Choice of hemodynamic monitoring is homogenous throughout German centers treating cardiac surgery patients. Norepinephrine is the first line catecholamine in cases of decrease in peripheral vascular resistance. However, catecholamine choice for low cardiac output syndrome varies considerably. HES was the primary colloid used for fluid resuscitation. After conduct of this survey, HES use was restricted by European regulatory authorities in critically ill patients and should only be considered as second-line fluid in surgical patients without renal impairment or severe coagulopathy. Large clinical studies addressing catecholamine and fluid therapy in cardiac surgery patients are lacking.

Health Outcomes with and without Use of Inotropic Therapy in Cardiac Surgery

Background:

Inotropes used to obtain short-term hemodynamic benefits in cardiac surgery may carry a risk of increased myocardial ischemia and adverse outcomes. This study investigated the association between intra- and postoperative use of inotropes and mortality and postoperative complications.

Methods:

A historic cohort study using prospective data from the Western Denmark Heart Registry on 6,005 consecutive cardiac surgery cases from three university hospitals. Propensity matching on pre- and intraoperative variables was used to identify a subgroup of patients receiving inotropic therapy (n = 1,170) versus comparable nonreceivers (n = 1,170) for outcome analysis.

Results:

Two thousand ninety-seven patients (35%) received inotropic therapy; 3,908 (65%) did not receive any inotropic or vasopressor support perioperatively. Among propensity-matched cohort including 2,340 patients 30-day mortality was 3.2% and 1-yr mortality was 7.6%. In the matched cohort, patients exposed to inotropes had a higher 30-day mortality (adjusted hazards ratio, 3.7; 95% CI, 2.1 to 6.5) as well as a higher 1-yr mortality rate (adjusted hazards ratio, 2.5; 95% CI, 1.8 to 3.5) compared with nonreceivers. Among propensity-matched, the following absolute events rates were observed: myocardial infarction 2.4%, stroke 2.8%, arrhythmia 35%, and renal replacement therapy 23.9%. Inotropic therapy was independently associated with postoperative myocardial infarction (adjusted odds ratio, 2.1; 95% CI, 1.4 to 3.0), stroke (adjusted odds ratio, 2.4; 95% CI, 1.4 to 4.3), and renal replacement therapy (adjusted odds ratio, 7.9; 95% CI, 3.8 to 16.4).

Conclusion:

Use of intra- and postoperative inotropes was associated with increased mortality and major postoperative morbidity.

Haemodynamic monitoring in the intensive care unit: results from a web-based Swiss survey

Background. The aim of this survey was to describe, in a situation of growing availability of monitoring devices and parameters, the practices in haemodynamic monitoring at the bedside. Methods. We conducted a Web-based survey in Swiss adult ICUs (2009-2010). The questionnaire explored the kind of monitoring used and how the fluid management was addressed. Results. Our survey included 71% of Swiss ICUs. Echocardiography (95%), pulmonary artery catheter (PAC: 85%), and transpulmonary thermodilution (TPTD) (82%) were the most commonly used. TPTD and PAC were frequently both available, although TPTD was the preferred technique. Echocardiography was widely available (95%) but seems to be rarely performed by intensivists themselves. Guidelines for the management of fluid infusion were available in 45% of ICUs. For the prediction of fluid responsiveness, intensivists rely preferentially on dynamic indices or echocardiographic parameters, but static parameters, such as central venous pressure or pulmonary artery occlusion pressure, were still used. Conclusions. In most Swiss ICUs, multiple haemodynamic monitoring devices are available, although TPTD is most commonly used. Despite the usefulness of echocardiography and its large availability, it is not widely performed by Swiss intensivists themselves. Regarding fluid management, several parameters are used without a clear consensus for the optimal method.