Postoperative Critical Care of the Adult Cardiac Surgical Patient. Part I: Routine Postoperative Care. Crit Care Med. 2015;43:1477-1497. [PMID: 25962078 DOI: 10.1097/ccm.0000000000001059]

Identifying Risk of Postoperative Cardiorespiratory Complications in OSA

BACKGROUND

Patients with OSA are at increased risk of postoperative cardiorespiratory complications and death. Attempts to stratify this risk have been inadequate, and predictors from large, well-characterized cohort studies are needed.

RESEARCH QUESTION

What is the relationship between OSA severity, defined by various polysomnography-derived metrics, and risk of postoperative cardiorespiratory complications or death, and which metrics best identify such risk?

STUDY DESIGN AND METHODS

In this cohort study, 6,770 consecutive patients who underwent diagnostic polysomnography for possible OSA and a procedure involving general anesthesia within a period of 2 years before and at least 5 years after polysomnography. Participants were identified by linking polysomnography and health databases. Relationships between OSA severity measures and the composite primary outcome of cardiorespiratory complications or death within 30 days of hospital discharge were investigated using univariable and multivariable analyses.

RESULTS

The primary outcome was observed in 5.3% (n = 361) of the cohort. Although univariable analysis showed strong dose-response relationships between this outcome and multiple OSA severity measures, multivariable analysis showed its independent predictors were: age older than 65 years (OR, 2.67 [95% CI, 2.03-3.52]; P < .0001), age 55.1 to 65 years (OR, 1.47 [95% CI, 1.09-1.98]; P = .0111), time between polysomnography and procedure of ≥ 5 years (OR, 1.32 [95% CI, 1.02-1.70]; P = .0331), BMI of ≥ 35 kg/m2 (OR, 1.43 [95% CI, 1.13-1.82]; P = .0032), presence of known cardiorespiratory risk factor (OR, 1.63 [95% CI, 1.29-2.06]; P < .0001), > 4.7% of sleep time at an oxygen saturation measured by pulse oximetry of < 90% (T90; OR, 1.91 [95% CI, 1.51-2.42]; P < .0001), and cardiothoracic procedures (OR, 7.95 [95% CI, 5.71-11.08]; P < .0001). For noncardiothoracic procedures, age, BMI, presence of known cardiorespiratory risk factor, and percentage of sleep time at an oxygen saturation of < 90% remained the significant predictors, and a risk score based on their ORs was predictive of outcome (area under receiver operating characteristic curve, 0.7 [95% CI, 0.64-0.75]).

INTERPRETATION

These findings provide a basis for better identifying high-risk patients with OSA and determining appropriate postoperative care.

Current Status of Adult Post-Cardiac Surgery Critical Care in Saudi Arabia

OBJECTIVE

The field of cardiac surgery in Saudi Arabia has developed significantly over the years, with more advanced procedures being performed for high-risk patients with multiple comorbidities. This poses challenging postoperative management issues requiring multidisciplinary, highly organized expert care in cardiovascular critical care. This survey aimed to describe the current state of postoperative critical care for cardiac surgeries in Saudi Arabia.

DESIGN

This e-mail survey developed by the Chapter of Adult Cardiovascular Critical Care of the Saudi Critical Care Society included 61 questions pertaining to the geographic distribution of adult cardiac surgery centers in Saudi Arabia, including what types of operations and how many operations are being performed, and information on intensive care units such as data on staffing, equipment, protocols, and outcome assessment in these units.

SETTING

The study was conducted in Saudi Arabia.

PARTICIPANTS

Participating physicians included representatives of adult intensive care units in all cardiac centers (N = 42).

INTERVENTIONS

There were no interventions in this study.

MEASUREMENTS AND MAIN RESULTS

Of the study cardiac centers, 71.4% have specialized cardiovascular critical care units for the postoperative care of cardiac patients and 42.9% are managed in a closed design by expert in-house physicians on a 24-hour basis. The estimated cardiac surgery intensive care unit bed capacity in Saudi Arabia is 7.3 (ranging from 3.0 in Qasim Region to 11.6 in Mecca Region) beds/1 million population, with 1.3 cardiac centers/1 million and 79 centers/1 million cardiovascular surgical patients. Several protocols are implemented in these critical care units with key performance indicators to meet the best quality of care.

CONCLUSIONS

Cardiac surgery intensive care units in Saudi Arabia have varying management structures, care practices, and healthcare provider staffing models, although most of the large-volume centers are adopting the intensivist-led team model of care. Guidelines are needed to standardize practice in all cardiac surgery centers regarding processes and protocols, intensive care unit staffing models, and reporting of outcomes and key performance indicators. Further studies are needed to study cardiac surgery intensive care unit factors related to patient outcomes after cardiac surgery.

Comparison of 4% Albumin and Ringer's Acetate on Hemodynamics in On-pump Cardiac Surgery: An Exploratory Analysis of a Randomized Clinical Trial

OBJECTIVES

Compare hemodynamics between 4% albumin and Ringer's acetate.

DESIGN

Exploratory analysis of the double-blind randomized ALBumin In Cardiac Surgery trial.

SETTING

Single-center study in Helsinki University Hospital.

PARTICIPANTS

We included 1,386 on-pump cardiac surgical patients.

INTERVENTION

We used 4% albumin or Ringer's acetate administration for cardiopulmonary bypass priming, volume replacement intraoperatively and 24 hours postoperatively.

MEASUREMENTS AND MAIN RESULTS

Hypotension (time-weighted average mean arterial pressure of <65 mmHg) and hyperlactatemia (time-weighted average blood lactate of >2 mmol/L) incidences were compared between trial groups in the operating room (OR), and early (0-6 hours) and late (6-24 hours) postoperatively. Associations of hypotension and hyperlactatemia with the ALBumin In Cardiac Surgery primary outcome (≥1 major adverse event [MAE]) were studied. In these time intervals, hypotension occurred in 118, 48, and 17 patients, and hyperlactatemia in 313, 131, and 83 patients. Hypotension and hyperlactatemia associated with MAE occurrence. Hypotension did not differ between the groups (albumin vs Ringer's: OR, 8.8% vs 8.5%; early postoperatively, 2.7% vs 4.2%; late postoperatively, 1.2% vs 1.3%; all p > 0.05). In the albumin group, hyperlactatemia was less frequent late postoperatively (2.9% vs 9.1%; p < 0.001), but not earlier (OR, 22.4% vs 23.6%; early postoperatively, 7.9% vs 11.0%; both p > 0.025 after Bonferroni-Holm correction).

CONCLUSIONS

In on-pump cardiac surgery, hypotension and hyperlactatemia are associated with the occurrence of ≥1 MAE. Compared with Ringer's acetate, albumin did not decrease hypotension and decreased hyperlactatemia only late postoperatively. Albumin's modest hemodynamic effect is concordant with the finding of no difference in MAEs between albumin and Ringer's acetate in the ALBumin In Cardiac Surgery trial.

A dimensional analysis of experienced intensive care unit nurses' clinical decision-making for bleeding after cardiac surgery

BACKGROUND

Bleeding following cardiac surgery is common and serious, yet a gap persists in understanding how experienced intensive care nurses identify and respond to such complications.

AIM

To describe the clinical decision-making of experienced intensive care unit nurses in addressing bleeding after cardiac surgery.

STUDY DESIGN

This qualitative study adopted the Recognition-Primed Decision Model as its theoretical framework. Thirty-nine experienced nurses from four adult intensive care units participated in semi-structured interviews based on the critical decision method. The interviews explored their clinical judgements and decisions in bleeding situations, and data were analysed through dimensional analysis, an alternative to grounded theory.

RESULTS

Participants maintained consistent vigilance towards post-cardiac surgery bleeding, recognizing it through a haemorrhagic dimension associated with blood loss and chest drainage and a hypovolemic dimension focusing on the repercussions of reduced blood volume. These dimensions organized their understanding of bleeding types (i.e., normal, medical, surgical, tamponade) and necessary actions. Their decision-making encompassed monitoring bleeding, identifying the cause, stopping the bleeding, stabilizing haemodynamic and supporting the patient and family. Participants also adapted their actions to specific circumstances, including local practices, professional autonomy, interprofessional dynamics and resource availability.

CONCLUSIONS

Nurses' decision-making was shaped by their personal attributes, the patient's condition and contextual circumstances, underscoring their expertise and pivotal role in anticipating actions and adapting to diverse conditions. The concept of actionability emerged as the central dimension explaining their decision-making, defined as the capability to implement actions towards specific goals within the possibilities and constraints of a situation.

RELEVANCE TO CLINICAL PRACTICE

This study underscores the need for continual updates to care protocols to align with current evidence and for quality improvement initiatives to close existing practice gaps. Exploring the concept of actionability further, developing adaptability-focused educational programmes, and understanding decision-making intricacies are crucial for informing nursing education and decision-support systems.

A single-centre retrospective study of the utility of routine chest X-ray post intrathoracic drain removal in cardiothoracic surgical patients

Routine chest X-ray (CXR) post intrathoracic drain removal in cardiac surgical patients is common practice to identify the presence of a pneumothorax following drain removal. Such pneumothoraces occur infrequently and rarely require intervention. We investigated the utility of routine CXR post drain removal and hypothesised that the practice is unnecessary and a possible area for significant cost saving. We conducted a single-centre, retrospective study of 390 patients who underwent cardiac surgery over a one-year period. Routine CXR post drain removal was reviewed for the presence of a pneumothorax. Rates of intervention post routine CXR were analysed to assess for clinical benefit obtained from this practice. Potential cost savings were calculated by the cost of a mobile CXR and by considering the radiographer's time. There were 15 pneumothoraces detected on routine CXR post drain removal. All pneumothoraces detected on routine post drain removal CXR were defined as small. No patients had a clinically significant pneumothorax requiring re-insertion of a chest drain. The potential cost saved by omitting routine CXR post drain removal was estimated to be approximately A$7750 per year. This study did not detect any clinically significant pneumothoraces requiring intervention. It also suggests that routine CXR post drain removal does not provide any clinical benefit and indicates that current practice should be reviewed.

Anaerobic Lactate Production Is Associated With Decreased Microcirculatory Blood Flow and Decreased Mitochondrial Respiration Following Cardiovascular Surgery With Cardiopulmonary Bypass

OBJECTIVES

Quantify the relationship between perioperative anaerobic lactate production, microcirculatory blood flow, and mitochondrial respiration in patients after cardiovascular surgery with cardiopulmonary bypass.

DESIGN

Serial measurements of lactate-pyruvate ratio (LPR), microcirculatory blood flow, plasma tricarboxylic acid cycle cycle intermediates, and mitochondrial respiration were compared between patients with a normal peak lactate (≤ 2 mmol/L) and a high peak lactate (≥ 4 mmol/L) in the first 6 hours after surgery. Regression analysis was performed to quantify the relationship between clinically relevant hemodynamic variables, lactate, LPR, and microcirculatory blood flow.

SETTING

This was a single-center, prospective observational study conducted in an academic cardiovascular ICU.

PATIENTS

One hundred thirty-two patients undergoing elective cardiovascular surgery with cardiopulmonary bypass.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients with a high postoperative lactate were found to have a higher LPR compared with patients with a normal postoperative lactate (14.4 ± 2.5 vs. 11.7 ± 3.4; p = 0.005). Linear regression analysis found a significant, negative relationship between LPR and microcirculatory flow index ( r = -0.225; β = -0.037; p = 0.001 and proportion of perfused vessels: r = -0.17; β = -0.468; p = 0.009). There was not a significant relationship between absolute plasma lactate and microcirculation variables. Last, mitochondrial complex I and complex II oxidative phosphorylation were reduced in patients with high postoperative lactate levels compared with patients with normal lactate (22.6 ± 6.2 vs. 14.5 ± 7.4 pmol O 2 /s/10 6 cells; p = 0.002).

CONCLUSIONS

Increased anaerobic lactate production, estimated by LPR, has a negative relationship with microcirculatory blood flow after cardiovascular surgery. This relationship does not persist when measuring lactate alone. In addition, decreased mitochondrial respiration is associated with increased lactate after cardiovascular surgery. These findings suggest that high lactate levels after cardiovascular surgery, even in the setting of normal hemodynamics, are not simply a type B phenomenon as previously suggested.

Barriers to Access to Cardiac Surgery: Canadian Situation and Global Context

Cardiovascular disease is the leading cause of morbidity and mortality worldwide. Cardiovascular care spans primary, secondary, and tertiary prevention and care, whereby tertiary care is particularly prone to disparities in care. Challenges in access to care especially affect low- and middle-income countries (LMICs), however, multiple barriers also exist and persist across high-income countries. Canada is lauded for its universal health coverage but is faced with health care system challenges and substantial geographic barriers. Canada possesses 203 active cardiac surgeons, or 5.02 per million population, ranging from 3.70 per million in Newfoundland and Labrador to 7.48 in Nova Scotia. As such, Canada possesses fewer cardiac surgeons per million population than the average among high-income countries (7.15 per million), albeit more than the global average (1.64 per million) and far higher than the low-income country average (0.04 per million). In Canada, adult cardiac surgeons are active across 32 cardiac centres, representing 0.79 cardiac centres per million population, which is just above the global average (0.73 per million). In addition to centre and workforce variations, barriers to care exist in the form of waiting times, sociodemographic characteristics, insufficient virtual care infrastructure and electronic health record interoperability, and health care governance fragmentation. Meanwhile, Canada has highly favourable surgical outcomes, well established postacute cardiac care infrastructure, considerable spending on health, robust health administrative data, and effective health technology assessment agencies, which provides a foundation for continued improvements in care. In this narrative review, we describe successes and challenges surrounding access to cardiac surgery in Canada and globally.

Maintaining moderate versus lower PEEP after cardiac surgery: a propensity-scored matched analysis

BACKGROUND

Setting positive end-expiratory pressure (PEEP) at around 5 cm H2O in the early postoperative period seems a common practice for most patients. It remains unclear if the routine application of higher levels of PEEP confers any meaningful clinical benefit for cardiac surgical patients. The aim of this study was to compare moderate versus conventional lower PEEP on patient-centered outcomes in the intensive care unit (ICU).

METHODS

This is a single-center retrospective study involving patients receiving cardiac surgery from June 2022 to May 2023. Propensity-score matching (PSM) was used to balance the baseline differences. Primary outcomes were the duration of mechanical ventilation and ICU length of stay. Secondary outcomes included PaO2/FiO2 ratio at 24 h and the need for prone positioning during ICU stay.

RESULTS

A total of 334 patients were included in the study, 102 (31%) of them received moderate PEEP (≥ 7 cm H2O) for the major time in the early postoperative period (12 h). After PSM, 79 pairs of patients were matched with balanced baseline data. The results showed that there was marginal difference in the distribution of mechanical ventilation duration (p = 0.05) and the Moderate PEEP group had a higher extubation rate at the day of T-piece trial (65 [82.3%] vs 52 [65.8%], p = 0.029). Applying moderate PEEP was also associated with better oxygenation. No differences were found regarding ICU length of stay and patients requiring prone positioning between groups.

CONCLUSION

In selective cardiac surgical patients, using moderate PEEP compared with conventional lower PEEP in the early postoperative period correlated to better oxygenation, which may have potential for earlier liberation of mechanical ventilation.

Biodegradable, Biocompatible, and Implantable Multifunctional Sensing Platform for Cardiac Monitoring

Cardiac monitoring after heart surgeries is crucial for health maintenance and detecting postoperative complications early. However, current methods like rigid implants have limitations, as they require performing second complex surgeries for removal, increasing infection and inflammation risks, thus prompting research for improved sensing monitoring technologies. Herein, we introduce a nanosensor platform that is biodegradable, biocompatible, and integrated with multifunctions, suitable for use as implants for cardiac monitoring. The device has two electrochemical biosensors for sensing lactic acid and pH as well as a pressure sensor and a chemiresistor array for detecting volatile organic compounds. Its biocompatibility with myocytes has been tested in vitro, and its biodegradability and sensing function have been proven with ex vivo experiments using a three-dimensional (3D)-printed heart model and 3D-printed cardiac tissue patches. Moreover, an artificial intelligence-based predictive model was designed to fuse sensor data for more precise health assessment, making it a suitable candidate for clinical use. This sensing platform promises impactful applications in the realm of cardiac patient care, laying the foundation for advanced life-saving developments.

Agitation during anaesthetic emergence: An observational study of adult cardiac surgery patients in two Australian intensive care units

BACKGROUND

Anaesthetic emergence agitation among adult patients being recovered after open cardiac and/or thoracic aorta surgery has not been described.

OBJECTIVES

The objective of this study was to characterise emergence agitation in terms of incidence, clinical features, and consequences in a cohort of cardiac surgery patients being recovered in the intensive care unit (ICU).

METHODS

A prospective, observational pilot study was implemented. Over a 5-week period, the study was conducted in two metropolitan hospitals in Victoria, Australia. The cohort comprised all patients admitted to the ICUs aged ≥18 years, who had undergone cardiac surgery via an open sternotomy with general anaesthetic, and whose emergence was directly observed. Emergence agitation was defined as a Richmond Agitation and Sedation Scale score of ≥+2.

RESULTS

Fifty patients were observed. Emergence agitation occurred in 24/50 (48%) of patients. Patients with emergence agitation experienced more clinical consequences than patients with calm emergence, including a significantly greater number of episodes of airway compromise (12/24, 50%, p < 0.001); ventilator dyssynchrony (23/24, 96%, p = 0.004); and hypertension (13/24, 54%, p = 0.004). Significant treatment interference (potentially dangerous patient movements such as pulling tubes) occurred with 23/24 patients (96%, p < 0.0001). Patients who underwent emergence agitation required significantly more interventions during anaesthetic emergence than patients who underwent a calm emergence. Interventions included extra nursing measures (16/24, 67%, p = 0.001) administration of sedative and/or opioid intravenous boluses (22/24, 92%, p = 0.001) and vasoactive agents (15/24, 63%, p = 0.05).

CONCLUSIONS

In patients recovering from cardiac surgery in the ICU, emergence agitation was clinically important. Immediate interventions were required to prevent and manage complications.

The symphony of open-heart surgical care: A mixed-methods study about interprofessional attitudes towards family involvement

PURPOSE

The overall aim of this study was to describe the attitudes towards family involvement in care held by nurses and medical doctors working in open-heart surgical care and the factors influencing these attitudes.

METHODS

Mixed-methods convergent parallel design. A web-based survey was completed by nurses (n = 267) using the Families' Importance in Nursing Care-Nurses Attitudes (FINC-NA) instrument and two open-ended questions, generating one quantitative and one qualitative dataset. Qualitative interviews with medical doctors (n = 20) were conducted in parallel, generating another qualitative dataset. Data were analysed separately according to each paradigm and then merged into mixed-methods concepts. Meta-inferences of these concepts were discussed.

RESULTS

The nurses reported positive attitudes in general. The two qualitative datasets from nurses and medical doctors resulted in the identification of seven generic categories. The main mixed-methods finding was the attitude that the importance of family involvement in care depends on the situation.

CONCLUSIONS

The dependence of family involvement on the situation may be due to the patient's and family's unique needs. If professionals' attitudes rather than the family's needs and preferences determine how the family is involved, care runs the risk of being unequal.

Perioperative Management in Pulmonary Endarterectomy

Pulmonary endarterectomy (PEA) is the treatment of choice for patients with chronic thromboembolic pulmonary hypertension (PH), provided lesions are proximal enough in the pulmonary vasculature to be surgically accessible and the patient is well enough to benefit from the operation in the longer term. It is a major cardiothoracic operation, requiring specialized techniques and instruments developed over several decades to access and dissect out the intra-arterial fibrotic material. While in-hospital operative mortality is low (<5%), particularly in high-volume centers, careful perioperative management in the operating theater and intensive care is mandatory to balance ventricular performance, fluid balance, ventilation, and coagulation to avoid or treat complications. Reperfusion pulmonary edema, airway hemorrhage, and right ventricular failure are the most problematic complications, often requiring the use of extracorporeal membrane oxygenation to bridge to recovery. Successful PEA has been shown to improve both morbidity and mortality in large registries, with survival >70% at 10 years. For patients not suitable for PEA or with residual PH after PEA, balloon pulmonary angioplasty and/or PH medical therapy may prove beneficial. Here, we describe the indications for PEA, specific surgical and perioperative strategies, postoperative monitoring and management, and approaches for managing residual PH in the long term.

Determining sex-specific preoperative haemoglobin levels associated with intraoperative red blood cell transfusion in cardiac surgery: a retrospective cohort study

BACKGROUND

Anaemic cardiac surgery patients are at greater risk of intraoperative red blood cell transfusion. This study questions the application of the World Health Organization population-based anaemia thresholds (haemoglobin <120 g L-1 in non-pregnant females and <130 g L-1 in males) as appropriate preoperative optimisation targets for cardiac surgery.

METHODS

A retrospective cohort study was conducted on adults ≥18 yr old undergoing cardiopulmonary bypass surgery. Logistic regression was applied to define sex-specific preoperative haemoglobin concentrations with reduced probability of intraoperative red blood cell transfusion for cardiac surgery patients.

RESULTS

Data on 4384 male and 1676 female patients were analysed. Binarily stratified multivariable logistic regression odds of receiving intraoperative red blood cell transfusion increased in cardiac surgery patients >45 yr old (odds ratio [OR] 1.84; 95% confidence interval [CI] 1.33-2.55), surgery urgency <30 days (OR 2.03; 95% CI 1.66-2.48), combined coronary artery bypass grafting and valve surgery, or other surgery types (OR 2.24; 95% CI 1.87-2.67), and female sex (OR 1.92; 95% CI 1.62-2.28). The odds decreased by 8.4% with each 1 g L-1 increase in preoperative haemoglobin (OR 0.92; 95% CI 0.91-0.92). Logistic regression predicted females required a preoperative haemoglobin concentration of 133 g L-1 and males 127 g L-1 to have a 15% probability of intraoperative transfusion.

CONCLUSIONS

The World Health Organization female anaemia threshold of haemoglobin <120 g L-1 disproportionately disadvantages female cardiac surgery patients. A preoperative haemoglobin concentration ≥130 g L-1 in adult cardiac surgery patients would minimise their overall probability of intraoperative red blood cell transfusion to <15%.

Anaesthetic emergence agitation after cardiac surgery: An intensive care staff survey

BACKGROUND

Anecdotal reports suggest that during emergence from anaesthesia, some post-cardiac surgery patients exhibit signs of agitation with concerning clinical features, including hypoxaemia, ventilation dysynchrony, and haemodynamic instability. This clinical phenomenon has not been described in the published literature.

OBJECTIVE

We aimed to investigate the perceptions and practice of intensive care unit staff members who have managed adult patients after cardiac surgery regarding emergence agitation, its clinical features, and treatment.

METHODS

A descriptive survey was conducted from December 2020 to January 2021 in two metropolitan hospitals. Items included Likert scale, multiple-item selection, and free-text responses.

RESULTS

There were 144 respondents (response rate: 55%). Post-cardiac surgery emergence agitation was witnessed by 143 respondents (99%). Fifty-seven (40%) reported encountering this clinical problem often. Clinical concerns included instabilities with airway or ventilation (347 items selected), cardiovascular system (189 items selected), and patient treatment interference, such as pulling tubes (229 items selected). Overall, 143 (99%) respondents re-sedated patients with emergence agitation, 138 (96%) added a narcotic bolus, and 121 respondents reported use of mechanical restraints (84%). Twenty-four respondents (2%) recalled receiving any formal anaesthetic emergence education, including after cardiac surgery.

CONCLUSION

Anaesthetic emergence agitation following cardiac surgery is a concerning clinical problem. Clinical management of emergence agitation was influenced more by clinical experience than research evidence. Further observational research is required to investigate clinical characteristics and inform evidence-based management practices and education.

Immediate Postoperative Management of Cardiac Surgery Patients

Cardiac surgery is quite common in the United States. Outcomes after cardiac surgery are not only dependent on how the surgery went and how the anesthesia care was provided intraoperatively but also on the optimal management in the postoperative critical care setting. It is of paramount importance that the cardiac intensivist has a comprehensive understanding of cardiopulmonary physiology and the sequelae of cardiopulmonary bypass. Most preventable deaths after cardiac surgery have been linked to postoperative problems in the intensive care unit (ICU).1,2 Failure to recognize and rescue a patient from potentially reversible complications is a cause of perioperative morbidity and mortality. Patients who undergo cardiac surgery often present with multiple rapidly changing clinical problems; they are initially unstable with extremely fluid and dynamic clinical status. Postoperative care of these patients requires knowledge of general fundamental concepts of patient care as well as concepts unique to this set of patients. The initial management of these patients as they return from the operating room is critical, because clinical errors at this time can have far-reaching implications. The initial management should begin even before the patient arrives in the cardiovascular intensive care unit (CVICU). It is vital that the cardiac intensivist reviews the chart and notes the type of surgery, indications, preoperative hemodynamic data, comorbid conditions, medications, and allergies. Upon the patient's arrival in the CVICU, a careful systematic assessment of the patient begins with obtaining a comprehensive handoff from the surgical and anesthesia team. The cardiac intensivist should ascertain what procedure was done in the operating room and inquire as to any intraoperative events that might impact the patient's postoperative course. Then, they should physically examine the patient as part of this initial evaluation. During the initial assessment, the intensivist should avoid focusing on any one issue and attempt to get a global picture of the patient's clinical status. A thorough knowledge of the specific monitoring and drug delivery lines is imperative, as is knowledge of where the drains are placed. Once the initial assessment is complete, specific issues can be identified, prioritized, and addressed.3,4.

Development of the Modern Cardiothoracic Intensive Care Unit and Current Management

The modern cardiothoracic intensive care unit (CTICU) developed as a result of advances in critical care, cardiology, and cardiac surgery. Patients undergoing cardiac surgery today are sicker, frailer, and have more complex cardiac and noncardiac morbidities. CTICU providers need to understand postoperative implications of different surgical procedures, complications that can occur in CTICU patients, resuscitation protocols for cardiac arrest, and diagnostic and therapeutic interventions such as transesophageal echocardiography and mechanical circulatory support. Optimum CTICU care requires a multidisciplinary team with collaboration between cardiac surgeons and critical care physicians with training and experience in the care of CTICU patients.

Trends in Cardiovascular Surgery in South Korea: A Nationwide Cohort Study from 2010 to 2019

OBJECTIVES

We aimed to investigate mortality and its associated factors in cardiovascular surgery-associated intensive care unit (ICU) admissions in South Korea from 2010 to 2019.

DESIGN

Population-based cohort study.

SETTING

Data from the National Health Insurance Service database in South Korea were used in this study.

PARTICIPANTS

All adult patients admitted to the ICU associated with cardiovascular surgery in South Korea between January 1, 2010 and December 31, 2019 were analyzed.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 62,794 ICU admissions associated with cardiovascular surgery were included in the analysis (median value of age: 65 years; 58.0% men). This included patients who underwent coronary artery bypass grafting (CABG) only (n = 10,704), valve-only surgery (n = 35,812), CABG + valve surgery (n = 3,230), aortic procedures (n = 7,968), and others (n = 5,080). The number of cardiovascular surgeries associated with ICU admissions was 4,409 in 2010, which gradually increased to 10,366 in 2019. The aortic procedure group had the highest 1-year mortality rate after cardiovascular surgery (15.7%), followed by the CABG + valve (13.2%), others (11.5%), CABG-only (9.5%), and valve-only (8.7%) groups. Invasive life support procedures during the ICU stay and hospital admission through the emergency room were potential risk factors for 1-year mortality after cardiovascular surgery.

CONCLUSIONS

Cardiovascular surgery-associated intensive care admissions gradually increased from 2010 to 2019 in South Korea. Among these patients, the highest 1-year mortality rate was observed in the aortic procedures group, followed by the CABG + valve, others, CABG-only, and valve-only groups.

A contemporary analysis of the volume-outcome relationship for extracorporeal membrane oxygenation in the United States

BACKGROUND

A paradoxical increase in mortality following extracorporeal membrane oxygenation at high-volume centers has previously been demonstrated. We examined the association between annual hospital volume and outcomes within a contemporary, national cohort of extracorporeal membrane oxygenation patients.

METHODS

All adults requiring extracorporeal membrane oxygenation for postcardiotomy syndrome, cardiogenic shock, respiratory failure, or mixed cardiopulmonary failure were identified in the 2016 to 2019 Nationwide Readmissions Database. Patients undergoing heart and/or lung transplantation were excluded. A multivariable logistic regression with hospital extracorporeal membrane oxygenation volume parametrized as restricted cubic splines was developed to characterize the risk-adjusted association between volume and mortality. The volume corresponding to the maximum of the spline (43 cases/year) was used to categorize centers as low- or high-volume.

RESULTS

An estimated 26,377 patients met the study criteria, and 48.7% were managed at high-volume hospitals. Patients at low- and high-volume hospitals had similar age, sex, and rates of elective admission. Notably, patients at high-volume hospitals less frequently required extracorporeal membrane oxygenation for postcardiotomy syndrome but more commonly for respiratory failure. After risk adjustment, high-volume hospital status was associated with reduced odds of in-hospital mortality, relative to low-volume hospitals (adjusted odds ratio 0.81, 95% confidence interval 0.78-0.97). Interestingly, patients at high-volume hospitals faced a 5.2-day increment in length of stay (95% confidence interval 3.8-6.5) and $23,500 in attributable costs (95% confidence interval 8,300-38,700).

CONCLUSION

The present study found that greater extracorporeal membrane oxygenation volume was associated with decreased mortality but higher resource use. Our findings may help inform policies regarding access to and centralization of extracorporeal membrane oxygenation care in the United States.

The effect of rewarming on hemodynamic parameters and arterial blood gases of patients after open-heart surgery: A randomized controlled trial

INTRODUCTION

Hypothermia after open-heart surgery can have potential side effects for patients.

AIM

This study aimed to examine the effects of rewarming on patients' hemodynamic and arterial blood gases parameters after open-heart surgery.

METHODS

This randomized controlled trial was performed in 2019 on 80 patients undergoing open-heart surgery at Tehran Heart Center, Iran. The subjects were consecutively recruited and randomly assigned to an intervention group (n=40) and a control group (n=40). After the surgery, the intervention group was warmed with an electric warming mattress while the control group warmed using a simple hospital blanket. The hemodynamic parameters of the two groups were measured 6 times and arterial blood gas was measured 3 times. Data were analyzed by independent samples t and Chi-squared tests, and repeated measures analysis.

RESULTS

Before the intervention, the two groups did not significantly differ in terms of hemodynamic and blood gas parameters. However, the two groups were significantly different in the mean heart rate, systolic blood pressure, diastolic blood pressure, mean arterial blood pressure, temperature, right and left lung drainage in the first half-hour, and the first to fourth hours after the intervention (p < 0.05). Furthermore, there was a significant difference between the mean arterial oxygen pressure of the two groups during and after rewarming (P <0.05).

CONCLUSION

Rewarming of patients after open-heart surgery can significantly affect hemodynamic and arterial blood gas parameters. Therefore, rewarming methods can be used safely to improve the patients' hemodynamic parameters after open-heart surgery.

Hemostatic effects of a dextran-based priming solution for cardiopulmonary bypass: A secondary analysis of a randomized clinical trial

INTRODUCTION

Intravascular fluids administered to patients may influence hemostasis. In patients undergoing cardiac surgery with cardiopulmonary bypass, the heart-lung machine is primed with 1300 ml of fluid. We assessed postoperative coagulation and platelet function in patients randomized to two different priming solutions, one colloid-based (dextran 40) and one crystalloid-based.

MATERIALS AND METHODS

Eighty-four elective cardiac surgery patients were randomized to either a dextran-based prime or Ringer's acetate with added mannitol. Blood samples were collected before, and 2 and 24 h after cardiopulmonary bypass. Coagulation was assessed by standard coagulation tests and rotational thromboelastometry. Platelet function was assessed with impedance aggregometry. Bleeding volumes and transfusion requirements were recorded.

RESULTS

Comparing the groups 2 h after bypass, the dextran group showed lower hemoglobin concentration, hematocrit, platelet count, and fibrinogen concentration, and higher INR and aPTT, as well as longer clot formation time (+41 ± 21 % vs. +8 ± 18 %, p < 0.001) and a larger reduction in fibrinogen-dependent clot strength (-37 ± 12 % vs. -7 ± 20 %, p < 0.001). Adenosine diphosphate-dependent platelet activation was reduced in the dextran group but not in the crystalloid group 2 h after bypass (-14 ± 29 % vs. -1 ± 41 %, p = 0.041). No significant between-group differences in hemostatic variables remained after 24 h, and no significant differences in perioperative bleeding volumes, re-explorations for bleeding, or transfusion rates were observed.

CONCLUSIONS

Compared to a crystalloid solution, a dextran-based prime had measurable negative impact on hemostatic variables but no detectable increase in bleeding volume or transfusion requirements in cardiac surgery patients.

Perioperative Risk Factors for Post-operative Pneumonia after Type A Acute Aortic Dissection Surgery

OBJECTIVE

Type A acute aortic dissection (TAAAD) is a dangerous and complicated condition with a high death rate before hospital treatment. Patients who are fortunate to receive prompt surgical treatment still face high in-hospital mortality. A series of post-operative complications further affects the prognosis. Post-operative pneumonia (POP) also leads to great morbidity and mortality. This study aimed to identify the prevalence as well as the risk factors for POP in TAAAD patients and offer references for clinical decisions to further improve the prognosis of patients who survived the surgical procedure.

METHODS

The study enrolled 89 TAAAD patients who underwent surgical treatment in Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei province, China from December 2020 to July 2021 and analyzed the perioperative data and outcomes of these patients. Logistic regression analyses were used to identify the risk factors for POP.

RESULTS

In the study, 31.5% of patients developed POP. Patients with POP had higher proportions of severe oxygenation damage, pneumothorax, reintubation, tracheotomy, renal replacement therapy, arrhythmia, gastrointestinal bleeding, and longer duration of mechanical ventilation, fever, ICU stay, and length of stay (all with P<0.05). The in-hospital mortality was 2.3%. Smoking, preoperative white blood cells, and intraoperative transfusion were the independent risk factors for POP in TAAAD.

CONCLUSION

Patients who underwent TAAAD surgery suffered poorer outcomes when they developed POP. Furthermore, patients with risk factors should be treated with caution.

Analgesic efficacy of butorphanol combined with sufentanil after heart valve surgery: A propensity score-matching analysis

Pain is common after heart valve surgery and can stimulate the sympathetic nervous system, causing hemodynamic instability and respiratory complications. Current treatments for postoperative pain are insufficient, and postoperative pain is difficult to control effectively with a single analgesic. Therefore, we investigated the analgesic efficacy of butorphanol with sufentanil after heart valve surgery and its hemodynamic effects. The records of 221 patients admitted to the intensive care unit after cardiac valve replacement between January 1, 2018, and May 31, 2021, were retrospectively analyzed. Patients were allocated to 2 groups based on the postoperative pain treatment they received: treatment group (administered butorphanol combined with sufentanil), and control group (administered conventional sufentanil analgesia). After propensity score matching for sex, age, Acute Physiology and Chronic Health Evaluation II score, type of valve surgery, and operation duration, 76 patients were included in the study, and analgesic efficacy, hemodynamic changes, and adverse drug reactions were compared between the 2 groups. After propensity score matching, the baseline characteristics were not significantly different between the groups. The histogram and jitter plot of the propensity score distribution indicated good matching. No significant differences were observed in the duration of mechanical ventilation, duration of stay in the intensive care unit, duration of total hospital stay, and hospitalization expenditure between the groups (P > .05). The treatment group had notably higher minimum systolic blood pressure (P = .024) and lower heart rate variability (P = .049) than those in the control group. Moreover, the treatment group exhibited better analgesic efficacy and had lower critical-care pain observation tool scores and consumption of sufentanil 24 hours after surgery than the control group (P < .05). The incidence of vomiting was notably lower in the treatment than in the control group (P = .028). Butorphanol combined with sufentanil can be used in patients after heart valve replacement. This combined treatment has good analgesic efficacy and is associated with reduced adverse drug reactions and, potentially, steady hemodynamics.

Outcomes of Prolonged ICU Stay for Patients Undergoing Cardiac Surgery in Australia and New Zealand

OBJECTIVE

To determine the effect of intensive care unit (ICU) length of stay (LOS) on hospital mortality and non-home discharge for patients undergoing cardiac surgery over a 16-year period in Australia and New Zealand.

DESIGN

A retrospective, multicenter cohort study covering the period January 1, 2004 to December 31, 2019.

SETTING

One hundred one hospitals in Australia and New Zealand that submitted data to the Australia New Zealand Intensive Care Society Adult Patient Database.

PARTICIPANTS

Adult patients (aged >18) who underwent coronary artery bypass grafting, valve surgery, or combined valve + coronary artery surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The authors analyzed 252,948 cardiac surgical patients from 101 hospitals, with a median age of 68.3 years (IQR 60-75.5), of whom 74.2% (187,632 of 252,948) were male patients. A U-shaped relationship was observed between ICU LOS and hospital mortality, with significantly elevated mortality at short (<20 hours) and long (>5 days) ICU LOS, which persisted after adjustment for illness severity and across clinically important subgroups (odds ratio for mortality with ICU LOS >5 days = 3.21, 95% CI 2.88-3.58, p < 0.001).

CONCLUSIONS

Prolonged duration of ICU LOS after cardiac surgery is associated with increased hospital mortality in a U-shaped relationship. An ICU LOS >5 days should be considered a meaningful definition for prolonged ICU stay after cardiac surgery.

Postoperative anion gap associates with short- and long-term mortality after cardiac surgery: A large-scale cohort study

Objective

To investigate whether postoperative anion gap (AG) is associated with short- and long-term mortality in patients following cardiac surgery.

Materials and methods

We conducted a retrospective cohort study of adults who underwent cardiac surgery from the Medical Information Mart for Intensive Care - III database. The generalized additive model (GAM), logistic regression, and Cox regression were performed to assess the correlations between AG levels and in-hospital, 90-day, and 4-year mortality. Linear regression was used to evaluate the associations between AG and length of stay (LOS).

Results

Totally, 6,410 subjects were enrolled in this study and classified into tertiles based on the initial AG levels. The GAM indicated a positive association between initial AG and in-hospital mortality after adjusting for potential confounders. Multivariate logistic analysis revealed that the risk of in-hospital mortality was higher among patients in tertile 2 (OR 2.05, 95% CI 1.11–3.76, P = 0.021) and tertile 3 (OR 4.51, 95% CI 2.57–7.91, P < 0.001) compared with those in tertile 1. For 90-day and 4-year mortality, multivariate Cox regression found similar associations between AG tertiles and mortality. The LOS in ICU and hospital also increased as AG tertiles increased. The E-value indicated robustness to unmeasured confounders.

Conclusion

This study found a positive association between postoperative AG levels and short- and long-term mortality among patients after cardiac surgery. This relationship warrants further research.

Correlation between transhepatic and subcostal inferior vena cava ultrasonographic images for evaluating fluid responsiveness after cardiac surgery

BACKGROUND

Echocardiographic monitoring during the postoperative period following cardiac surgery is essential because patients often develop hemodynamic instability from hypovolemia and other causes. Therefore, predicting fluid responsiveness by measuring respirophasic variation in the inferior vena cava (IVC) is essential in this population. Yet it is not always possible to evaluate using the traditional subcostal view.

METHODS

This cross-sectional study of 36 consecutive adult patients who underwent cardiac surgery included those in whom it was possible to adequately visualize the IVC in both the subcostal and transhepatic views. The maximum and minimum diameters and respirophasic variation were measured in each view. These views were then correlated and the capacity of the transhepatic view to predict fluid responsiveness was evaluated.

RESULTS

There was a strong positive correlation between IVC maximum and minimum diameters and respirophasic variation according to subcostal and transhepatic views. Evaluation of IVC respirophasic variation indices using the transhepatic view also showed high sensitivity for predicting fluid responsiveness.

CONCLUSION

There is a correlation between the transhepatic and subcostal views for determining maximum and minimum IVC diameters, and distensibility and variability indices for predicting fluid responsiveness in postoperative cardiac surgery patients.

Relationship Between Initial Urine Output and Mortality in Patients Hospitalized in Cardiovascular Intensive Care Units: More Is Not Better

Backgrounds

Decreased urine output (UO) is associated with adverse outcomes in certain patients, but this effect in patients admitted for cardiovascular diseases is still unproven. Moreover, the relationship between increased UO and prognosis is also unclear.

Objective

To investigate the relationship between decreased or increased UO and outcomes in patients with the cardiovascular intensive care unit (CICU).

Methods

This study was a retrospective cohort analysis based on the medical information mart for intensive care III (MIMIC-III) database. The patients' data were extracted from the Beth Israel Deaconess Medical Center (Boston, MA) between 2001 and 2012. With the initial 24-h UO range from 0.5 to 1.0 ml/kg/h as the reference, participants were divided into the several groups. The primary outcome was 30-day mortality. The secondary outcomes were 90-day mortality, ICU mortality, hospital mortality, use of mechanical ventilation (MV), and vasopressor agents in the first 24-h of ICU. The association between UO and mortality was assessed by multivariable logistic regression.

Results

A total of 13,279 patients admitted to CICU were included. Low UO (< 0.5 ml/kg/h) was strongly associated with 30-day mortality (unadjusted OR = 3.993, 95% CI: 3.447–4.625, p < 0.001), and very high UO (≥ 2.0 ml/kg/h) was also a significantly risk factor for 30-day mortality (Unadjusted OR = 2.069, 95% CI: 1.701–2.516, p < 0.001) compared with the reference. The same effects also were shown in the multivariable logistic regression, adjusted by age, gender, vital signs, common comorbidities, and use of diuretics, with an adjusted OR of 2.023 (95% CI: 1.693–2.417, p < 0.001) for low UO and 1.771 (95% CI: 1.389–2.256, p < 0.001) for very high UO. Moreover, both decreased UO and increased UO were risk factors for 90-day mortality, ICU mortality, hospital mortality, use of MV and vasopressor agents.

Conclusion

The decreased and increased UO both were significantly associated with short-term mortality, the relationship between UO and mortality was U-shape rather than linear.

Transverse thoracic muscle plane block as a routine strategy for cardiac enhanced recovery after surgery in sternotomy: A retrospective analysis

ABSTRACT

The aim of this study is to retrospectively analyze and evaluate the effect of transverse thoracic muscle plane (TTP) block as a routine analgesic strategy for cardiac enhanced recovery after surgery in sternotomy.Patients received TTP block after general anesthesia and tracheal intubation were included in this study. The baseline clinical data of the patients, intraoperative use of sufentanil, internal mammary artery separating time, the postoperative duration of invasive ventilation, visual analogue scale, the compression times of patient-controlled intravenous analgesia in the first 3 days after surgery, and postoperative nausea and vomiting were recorded.A total of 104 cases was included and divided to G group (without TTP block) and TTP group (with TTP). Sufentanil use (sufentanil dose/min, sufentanil dose/kg body weight, sufentanil dose/[min kg]) in TTP group was significantly lower than that of G group. In G group, intraoperative use of sufentanil was correlated to the duration of anesthesia (P = .035). The postoperative visual analogue scale pain scores and the compression times of patient-controlled intravenous analgesia in the TTP group were significantly decreased compared with G group (P < .01). The postoperative duration of invasive ventilation of patients with normal and mildly impaired pulmonary function was significantly correlated to the use of sufentanil (P = .027, .009).TTP block has certain analgesic effect and can reduce sufentanil use in medium-length cardiac surgery and postoperative use of opioids. It is indicated that TTP block can be used as a routine enhanced recovery after surgery strategy for sternotomy in cardiac surgery.

Post-operative management of hypertrophic obstructive cardiomyopathy

Hypertrophic obstructive cardiomyopathy patients are at increased risk of sudden cardiac arrest due to dynamic left ventricular outflow tract obstruction, myocardial ischaemia and arrhythmias. Septal myectomy remains the gold standard therapy for patients with hypertrophic obstructive cardiomyopathy (HOCM) refractory to other therapy. This review comprehensively focuses on the post-operative management and complications of HOCM patients undergoing surgical correction. Although these patients are at risk of various perioperative complications from anaesthesia and surgery due to the underlying complexity of their disease, surgical myectomy is associated with excellent long-term outcomes if carried out in experienced centers.

Hyperlactatemia as a prognostic indicator for contemporary left ventricular assist device implantation

BACKGROUND

This study evaluates the impact of early post-operative hyperlactatemia on outcomes after left ventricular assist device (LVAD) implantation.

METHODS

Adults undergoing contemporary LVAD implantation between 2009 to 2018 were included. Peak post-operative (within 24-h) lactate level was analyzed. The cohort was stratified into patients with and without post-operative hyperlactatemia, which was defined as peak > 3.5 mMol/L. The primary outcome was survival, and secondary outcomes included post-implant adverse events. Sub-analysis was performed to evaluate the impact of time for lactate normalization, define as lactate < 2 mMol/L. Multivariable cox regression was used for risk-adjustment.

RESULTS

A total of 190 patients were included. 49.5% experienced early post-operative hyperlactatemia. Patients with post-operative hyperlactatemia had significantly higher rates of post-implant complications including re-operation, renal failure, and hepatic dysfunction (all, p ≤ 0.05). The post-operative hyperlactatemia group also had significantly higher 90-day and 1-year mortality rates following LVAD implantation (both, p ≤ 0.05). In multivariable analysis, post-operative hyperlactatemia (HR 1.69, 95% CI 1.09-2.60, p = 0.02) was an independent predictor of overall mortality following LVAD implantation. Increased time for normalization of lactate also adversely impacted risk-adjusted overall mortality following implantation as a continuous variable (HR 1.02, 95% CI 1.01-1.03, p < .001).

CONCLUSIONS

This study demonstrates early post-operative hyperlactatemia is associated with increased morbidity and mortality following LVAD implantation. Even early post-operative lactate trends within the first 24 post-operative hours appear to have a useful role in predicting longitudinal survival following implantation. Careful monitoring of post-operative lactate with measures to normalize levels should be considered in the early care of LVAD patients.

Cardiovascular nurses' experiences of working in the COVID-19 intensive care unit: A qualitative study

BACKGROUND

Cardiovascular nurses' skills and experiences of cardiac critical care, management of cardiovascular emergencies, and mechanical circulatory support have been considered vital in providing nursing care for COVID-19 patients in intensive care units during the COVID-19 pandemic. To our knowledge, there are no studies have focused on the contribution and experiences of cardiovascular nurses in the critical care of COVID-19 patients.

OBJECTIVES

To explore the experiences of cardiovascular nurses working in a COVID-19 intensive care unit during the pandemic.

METHODS

The study was conducted as a qualitative study with phenomenological approach in June-December 2020. Study data were gathered from ten cardiovascular nurses through semi-structured interviews.

RESULTS

Six themes emerged from the interview data: the duties and responsibilities in a COVID-19 intensive care unit; the differences of COVID-19 intensive care unit practices from cardiovascular practices; the transferrable skills of cardiovascular nurses in a COVID-19 intensive care unit; the difficulties encountered working in a COVID-19 intensive care unit; the difficulty of working with personal protective equipment; and the psychosocial effects of working in a COVID-19 intensive care unit.

CONCLUSION

Cardiovascular nurses made an important contribution to the management of nursing services with their experiences and skills in the COVID-19 pandemic.

Monitoring, management, and outcome of hypotension in Intensive Care Unit patients, an international survey of the European Society of Intensive Care Medicine

INTRODUCTION

Hypotension in the ICU is common, yet management is challenging and variable. Insight in management by ICU physicians and nurses may improve patient care and guide future hypotension treatment trials and guidelines.

METHODS

We conducted an international survey among ICU personnel to provide insight in monitoring, management, and perceived consequences of hypotension.

RESULTS

Out of 1464 respondents, 1197 (81.7%) were included (928 physicians (77.5%) and 269 nurses (22.5%)). The majority indicated that hypotension is underdiagnosed (55.4%) and largely preventable (58.8%). Nurses are primarily in charge of monitoring changes in blood pressure, physicians are in charge of hypotension treatment. Balanced crystalloids, dobutamine, norepinephrine, and Trendelenburg position were the most frequently reported fluid, inotrope, vasopressor, and positional maneuver used to treat hypotension. Reported complications believed to be related to hypotension were AKI and myocardial injury. Most ICUs do not have a specific hypotension treatment guideline or protocol (70.6%), but the majority would like to have one in the future (58.1%).

CONCLUSIONS

Both physicians and nurses report that hypotension in ICU patients is underdiagnosed, preventable, and believe that hypotension influences morbidity. Hypotension management is generally not protocolized, but the majority of respondents would like to have a specific hypotension management protocol.

Manual zur Indikation und Durchführung spezieller echokardiographischer Anwendungen

Das zweite Manual zur Indikation und Durchführung der Echokardiographie bezieht sich auf spezifische Anwendungen der Echokardiographie und besondere Fragestellungen bei speziellen Patientengruppen. Dabei stehen v. a. praktische Aspekte im Vordergrund. Methodisch etabliert sind die transösophageale Echokardiographie, die Stressechokardiographie und die Kontrastechokardiographie. Bei nahezu allen echokardiographischen Untersuchungen spielen aktuell 3‑D-Echokardiographie und Deformationsbildgebung eine Rolle. Das gesamte Spektrum der echokardiographischen Möglichkeiten wird derzeit in Notfall- und Intensivmedizin, bei der Überwachung und Führung von Katheterinterventionen, bei strukturellen Herzerkrankungen, bei herzchirurgischen Operationen, bei der Nachsorge von kardialen Unterstützungssystemen, bei kongenitalen Vitien im Erwachsenenalter und bei der Versorgung von hochinfektiösen Patienten in Pandemiezeiten angewandt. Die diagnostischen Fortschritte der konventionellen und modernen echokardiographischen Anwendungen stehen im Fokus dieses Manuals. Die 3‑D-Echokardiographie zur Charakterisierung der kardialen Morphologie und die Deformationsbildgebung zur Objektivierung der kardialen Funktion sind bei vielen Indikationen im klinischen Alltag etabliert. Die Stressechokardiographie zur Ischämie‑, Vitalitäts- und Vitiendiagnostik, die Bestimmung der koronaren Flussreserve und die Kontrastechokardiographie bei der linksventrikulären Wandbewegungsanalyse und kardialen Tumordetektion finden zunehmend klinische Anwendung. Wie für die konventionelle Echokardiographie im ersten Manual der Echokardiographie 2009 beschrieben, erfordert der Einsatz moderner echokardiographischer Verfahren die standardisierte Dokumentation und Akquisition bestimmter Bildsequenzen bei optimierter Geräteeinstellung, da korrekte und reproduzierbare Auswertungen nur bei guter Bildqualität möglich sind.

Impact of early massive transfusion and blood component ratios in patients undergoing left ventricular assist device implantation

BACKGROUND

This study evaluates the impact of early massive transfusion and blood component ratios on outcomes following left ventricular assist device (LVAD) implantation.

METHODS

Adults undergoing LVAD implantation between 2009 and 2018 at a single institution were included. Transfusions were analyzed during the intraoperative and the initial 24-h postoperative period. Patients were stratified into massive and nonmassive transfusion groups. The primary outcome was survival, and secondary outcomes included postoperative complications. Sub-analyses were performed to evaluate the impact of balanced transfusion.

RESULTS

A total of 278 patients were included. A total of 45.3% (n = 126) required massive transfusions. The massive transfusion group experienced significantly higher rates of postimplant adverse events, including reoperation, renal failure, and hepatic dysfunction (all, p ≤ .05). Furthermore, the massive transfusion group had significantly lower 30-day, 90-day, 1-year, 2-year, and overall survival rates following LVAD implantation (all, p < .05). In multivariable analysis, massive transfusion significantly impacted overall risk-adjusted mortality rate (hazard ratio: 2.402, 95% confidence Interval: 1.677-3.442, p < .001). In the sub-analyses evaluating the impact of balanced massive transfusion, balanced fresh frozen plasma to packed red blood cell (pRBC) transfusion did not provide any survival benefit (all, p > .05). However, balanced platelet to pRBC massive transfusion did improve 2-year and overall mortality rates in the massive transfusion cohort (both, p ≤ .05).

CONCLUSIONS

This study demonstrates a significant association between early massive transfusion and adverse outcomes following LVAD implantation. Balancing platelet to pRBC transfusion in the early postoperative period may help mitigate some of these detrimental effects of massive transfusion on subsequent survival.

Dual-modality Volume Measurement integrated on a Ventricular Assist Device

OBJECTIVE

Ventricular assist devices (VADs) are implanted in patients suffering from end-stage heart failure to sustain the blood circulation. Real-time volume measurement could be a valuable tool to monitor patients and enable physiological control strategies to provide individualized therapy. However, volume measurement using one sensor modality requires re-calibration in the critical time post VAD implantation.

METHODS

To overcome this limitation, we have integrated ultrasound and impedance volume measurement techniques into a cannula of an apical VAD. We tested both modalities across a volume range from 140-420 mL using two differently sized and shaped biventricular silicon heart phantoms, which were subjected to physiological pressures in an in-vitro test bench. We compared results from standard calibrated measurements with calculations found by a quadratic optimization for the single modality and their combination (dual-modality) and validated the results using twofold cross-validation.

RESULTS

The dual-modality approach resulted in most favorable limits of agreement (LOA) of -0.83 ± 1.54% compared to -13.88 ± 5.90% for ultrasound and -43.45 ± 10.28% for electric impedance, separately.

CONCLUSION

The results of the dual-modality approach were as accurate as the standard calibrated measurement and valid over a large range of volumes (140-420 mL). In this in-vitro study, we show how a dual-modality ventricular volume measurement of ultrasound and electric impedance increases the robustness and renders calibration obsolete.

SIGNIFICANCE

Ventricular volumes could be measured accurately in the critical period post VAD implantation despite ventricular remodeling.

Optimizing the Recognition and Treatment of In-Hospital Stroke: Evaluation of the 2CAN Score

OBJECTIVES

Stroke-like symptoms may be difficult to appreciate due to the high incidence of stroke mimics (e.g., delirium) in the inpatient population. Many centers have adopted inpatient-specific stroke protocols with the aim of improving time to diagnosis and treatment. We aimed to assess one of these instruments, the "2CAN" score, in our patient population.

MATERIALS AND METHODS

A retrospective chart review was conducted for all inpatients for whom our Brain Attack Team (BAT) was called between January 2015 and June 2019. Patients were excluded if they had stroke prior to current admission, were in the emergency department at the time of BAT call, or had incomplete documentation. The 2CAN score was calculated for each patient.

RESULTS

The BAT was activated 201 times, and 110 patients met inclusion criteria. Twenty percent of patients had a history of atrial fibrillation, 72% hypertension, and 36% diabetes. Median NIHSS was 14.5 (IQR 5-24). Only 18% of stroke calls occurred within 24 h of hospital admission. The mean 2CAN score was 2.8. Ninety-seven (88%) patients received a final diagnosis of ischemic stroke and 13 (12%) of stroke mimics. There was no difference between 2CAN scores in the stroke and mimic groups (P = 0.91). A 2CAN score of ≥ 2 had sensitivity 83.5%, specificity 23.1%, PPV 89.0%, and NPV 15.8% for stroke.

CONCLUSIONS

The 2CAN score was derived and validated in a single academic center as a tool to recognize inpatient stroke. The 2CAN score had good sensitivity and positive predictive value for stroke in our cohort, but poor specificity.

Change in left ventricular velocity time integral during Trendelenburg maneuver predicts fluid responsiveness in cardiac surgical patients in the operating room

BACKGROUND

Fluid responsiveness is an important topic for clinicians. We investigated whether changes in left ventricular outflow tract (LVOT) velocity time integral (VTI) during a Trendelenburg position (TP) maneuver can predict fluid responsiveness as a non-invasive marker in coronary artery bypass graft (CABG) surgery patients in the operating room.

METHODS

This prospective, single-center observational study, performed in the operating room, enrolled 65 elective CABG patients. Hemodynamic data coupled with transesophageal echocardiography monitoring of the LVOT VTI and the peak velocity were collected at each step [baseline 1, TP, baseline 2 and fluid challenge (FC)]. Patients whose VTI increased ≥15% after FC (500 mL of Gelofusine infusion within 30 min) were considered responders.

RESULTS

Twenty-eight (43.1%) patients were responders to fluid administration. VTI changes during the TP maneuver predicted fluid responsiveness with an area under the receiver operating characteristic curve (AUC) of 0.90 (95% CI, 0.79-0.96), with a sensitivity of 100%, and a specificity of 70% at a threshold of 10% (gray zone, 8-15%). The increase in VTI during the TP was correlated with the VTI changes induced by FC (r=0.61, P<0.0001). Changes in peak velocity and pulse pressure during the TP were poorly predictive of fluid responsiveness, with an AUC of 0.72 (95% CI: 0.60-0.82) and 0.66 (95% CI: 0.53-0.77), respectively.

CONCLUSIONS

An increase in VTI induced by the TP could predict fluid responsiveness in CABG patients in the operating room. However, changes in peak velocity and pulse pressure stimulated by the TP could not reliably predict fluid responsiveness.

Definition and incidence of hypotension in intensive care unit patients, an international survey of the European Society of Intensive Care Medicine

INTRODUCTION

Although hypotension in ICU patients is associated with adverse outcome, currently used definitions are unknown and no universally accepted definition exists.

METHODS

We conducted an international, peer-reviewed survey among ICU physicians and nurses to provide insight in currently used definitions, estimations of incidence, and duration of hypotension.

RESULTS

Out of 1394 respondents (1055 physicians (76%) and 339 nurses (24%)), 1207 (82%) completed the questionnaire. In all patient categories, hypotension definitions were predominantly based on an absolute MAP of 65 mmHg, except for the neuro(trauma) category (75 mmHg, p < 0.001), without differences between answers from physicians and nurses. Hypotension incidence was estimated at 55%, and time per day spent in hypotension at 15%, both with nurses reporting higher percentages than physicians (estimated mean difference 5%, p = 0.01; and 4%, p < 0.001).

CONCLUSIONS

An absolute MAP threshold of 65 mmHg is most frequently used to define hypotension in ICU patients. In neuro(trauma) patients a higher threshold was reported. The majority of ICU patients are estimated to endure hypotension during their ICU admission for a considerable amount of time, with nurses reporting a higher estimated incidence and time spent in hypotension than physicians.

Year in Review 2020: Noteworthy Literature in Cardiothoracic Critical Care

This year will be forever marked by the drastic changes COVID-19 wrought on our personal and professional lives. New roles and challenges in critical care have forced us to be constantly nimble and flexible in how we approach medicine. The strain of these challenges is apparent throughout the health care community and our society as a whole. Despite this adversity, 2020 will also be remembered for fantastic advances in research. This article is a collection of influential and exciting studies published in 2020 encompassing a broad swath of critical care with a focus on cardiothoracic critical care. Themes include examinations of early extracorporeal membrane oxygenation support for out-of-hospital cardiac arrest patients, the impact of sedation and other risk factors on perioperative mortality, a novel fluid resuscitation strategy following cardiac surgery, and advances in the fields of heart and lung transplantation as well as how they were affected by COVID-19. Given that many cardiothoracic intensivists were redeployed to the care of SARS-CoV-2 patients, we also discuss important advances in therapeutics for the virus.

Transesophageal Echocardiography in Patients Undergoing Coronary Artery Bypass Graft Surgery

BACKGROUND

The impact of utilization of intraoperative transesophageal echocardiography (TEE) at the time of isolated coronary artery bypass grafting (CABG) on clinical decision making and associated outcomes is not well understood.

OBJECTIVES

The purpose of this study was to determine the association of TEE with post-CABG mortality and changes to the operative plan.

METHODS

A retrospective cohort study of planned isolated CABG patients from the Society of Thoracic Surgeons Adult Cardiac Surgery Database between January 1, 2011, and June 30, 2019, was performed. The exposure variable of interest was use of intraoperative TEE during CABG compared with no TEE. The primary outcome was operative mortality. The association of TEE with unplanned valve surgery was also assessed.

RESULTS

Of 1,255,860 planned isolated CABG procedures across 1218 centers, 676,803 (53.9%) had intraoperative TEE. The percentage of patients receiving intraoperative TEE increased over time from 39.9% in 2011 to 62.1% in 2019 (p trend <0.0001). CABG patients undergoing intraoperative TEE had lower odds of mortality (adjusted odds ratio: 0.95; 95% confidence interval: 0.91 to 0.99; p = 0.025), with heterogeneity across STS risk groups (p interaction = 0.015). TEE was associated with increased odds of unplanned valve procedure in lieu of planned isolated CABG (adjusted odds ratio: 4.98; 95% confidence interval: 3.98 to 6.22; p < 0.0001).

CONCLUSIONS

Intraoperative TEE usage during planned isolated CABG is associated with lower operative mortality, particularly in higher-risk patients, as well as greater odds of unplanned valve procedure. These findings support usage of TEE to improve outcomes for isolated CABG for high-risk patients.

Cerebral autoregulation in the operating room and intensive care unit after cardiac surgery

BACKGROUND

Cerebral autoregulation monitoring is a proposed method to monitor perfusion during cardiac surgery. However, limited data exist from the ICU as prior studies have focused on intraoperative measurements. Our objective was to characterise cerebral autoregulation during surgery and early ICU care, and as a secondary analysis to explore associations with delirium.

METHODS

In patients undergoing cardiac surgery (n=134), cerebral oximetry values and arterial BP were monitored and recorded until the morning after surgery. A moving Pearson's correlation coefficient between mean arterial proessure (MAP) and near-infrared spectroscopy signals generated the cerebral oximetry index (COx). Three metrics were derived: (1) globally impaired autoregulation, (2) MAP time and duration outside limits of autoregulation (MAP dose), and (3) average COx. Delirium was assessed using the 3-Minute Diagnostic Interview for CAM-defined Delirium (3D-CAM) and the Confusion Assessment Method for the ICU (CAM-ICU). Autoregulation metrics were compared using χ² and rank-sum tests, and associations with delirium were estimated using regression models, adjusted for age, bypass time, and logEuroSCORE.

RESULTS

The prevalence of globally impaired autoregulation was higher in the operating room vs ICU (40% vs 13%, P<0.001). The MAP dose outside limits of autoregulation was similar in the operating room and ICU (median 16.9 mm Hg×h; inter-quartile range [IQR] 10.1-38.8 vs 16.9 mm Hg×h; IQR 5.4-35.1, P=0.20). In exploratory adjusted analyses, globally impaired autoregulation in the ICU, but not the operating room, was associated with delirium. The MAP dose outside limits of autoregulation in the operating room and ICU was also associated with delirium.

CONCLUSIONS

Metrics of cerebral autoregulation are altered in the ICU, and may be clinically relevant with respect to delirium. Further studies are needed to investigate these findings and determine possible benefits of autoregulation-based MAP targeting in the ICU.

Patient's experiences of endotracheal tubes and suction following cardiac surgery

BACKGROUND

There is a growing body of evidence addressing the patient experience of intensive care, including patient reports that the presence of an endotracheal tube is bothersome and distressing, and that endotracheal suction is moderately to extremely painful. Yet there remains little information about the patient experience of the endotracheal tube and suction in those patients receiving planned short-term mechanical ventilation.

AIMS AND OBJECTIVES

This study aimed to describe the patient experience of the endotracheal tube and suction, following mechanical ventilation in post-operative cardiac surgical patients.

DESIGN

This qualitative study used inductive thematic analysis. Participants having planned cardiac surgery, anticipated to receive less than 12-hours mechanical ventilation, were approached pre-operatively and written consent provided.

METHODS

Ten participants were recruited using purposive sampling. Semi-structured interviews were conducted between days four and six post-operatively. One researcher interviewed all participants; two researchers independently read, coded, and agreed themes.

FINDINGS

None of the participants recalled endotracheal suction, while half had no recollection of the endotracheal tube. Three themes were identified; the experience of the endotracheal tube and extubation, the experience of emerging from sedation, and participants concerns about the future. The presence of the endotracheal tube was described as bothersome, whilst breathing through the tube and extubation were described as 'weird' and 'strange' but not painful.

CONCLUSIONS

Knowledge of the patient experience can help inform nursing practice by improving pre and post-operative care planning.

RELEVANCE TO CLINICAL PRACTICE

This study adds to the body of knowledge about the patient experience of the endotracheal tube and extubation.

TRIAL REGISTRATION

Prospective registration with the Australian New Zealand Clinical Trials Registry. www.anzctr.org.au (ACTRN12616001515482).

Point-of-Care Ultrasound (POCUS) for the Cardiothoracic Anesthesiologist

Point-of-Care Ultrasound (POCUS) is a valuable bedside diagnostic tool for a variety of expeditious clinical assessments or as guidance for a multitude of acute care procedures. Varying aspects of nearly all organ systems can be evaluated using POCUS and, with the increasing availability of affordable ultrasound systems over the past decade, many now refer to POCUS as the 21^st-century stethoscope. With the current available and growing evidence for the clinical value of POCUS, its utility across the perioperative arena adds enormous benefit to clinical decision-making. Cardiothoracic anesthesiologists routinely have used portable ultrasound systems for nearly as long as the technology has been available, making POCUS applications a natural extension of existing cardiothoracic anesthesia practice. This narrative review presents a broad discussion of the utility of POCUS for the cardiothoracic anesthesiologist in varying perioperative contexts, including the preoperative clinic, the operating room (OR), intensive care unit (ICU), and others. Furthermore, POCUS-related education, competence, and certification are addressed.

Improved Estimation of Left Ventricular Volume from Electric Field Modeling

Volume measurement is beneficial in left ventricular assist device (LVAD) therapy to quantify patient demand. In principle, an LVAD could provide a platform that allows bioimpedance measurements inside the ventricle without requiring additional implants. Conductance measured by the LVAD can then be used to estimate the ventricular radius, which can be applied to calculate ventricular volume. However, established methods that estimate radius from conductance require elaborate individual calibration or show low accuracy. This study presents two analytical calculation methods to estimate left ventricular radius from conductance using electric field theory. These methods build on the established method of Wei, now considering the dielectric properties of muscle and background tissue, the refraction of the electric field at the blood-muscle boundary, and the changes of the electric field caused by the measurements. The methods are validated in five glass containers of different radius. Additional bioimpedance measurements are performed in in-vitro models that replicate the left ventricle's shape and conductive properties. The proposed analytical calculation methods estimate the radii of the containers and the in-vitro models with higher accuracy and precision than Wei's method. The lead method performs excellently in glass cylinders over a wide range of radii (bias: 1.66%-2.48%, limits of agreement < 16.33%) without calibration to specific geometries.

Vasopressin in vasoplegic shock: A systematic review

BACKGROUND

Vasoplegic shock is a challenging complication of cardiac surgery and is often resistant to conventional therapies for shock. Norepinephrine and epinephrine are standards of care for vasoplegic shock, but vasopressin has increasingly been used as a primary pressor in vasoplegic shock because of its unique pharmacology and lack of inotropic activity. It remains unclear whether vasopressin has distinct benefits over standard of care for patients with vasoplegic shock.

AIM

To summarize the available literature evaluating vasopressin vs non-vasopressin alternatives on the clinical and patient-centered outcomes of vasoplegic shock in adult intensive care unit (ICU) patients.

METHODS

This was a systematic review of vasopressin in adults (≥ 18 years) with vasoplegic shock after cardiac surgery. Randomized controlled trials, prospective cohorts, and retrospective cohorts comparing vasopressin to norepinephrine, epinephrine, methylene blue, hydroxocobalamin, or other pressors were included. The primary outcomes of interest were 30-d mortality, atrial/ventricular arrhythmias, stroke, ICU length of stay, duration of vasopressor therapy, incidence of acute kidney injury stage II-III, and mechanical ventilation for greater than 48 h.

RESULTS

A total of 1161 studies were screened for inclusion with 3 meeting inclusion criteria with a total of 708 patients. Two studies were randomized controlled trials and one was a retrospective cohort study. Primary outcomes of 30-d mortality, stroke, ventricular arrhythmias, and duration of mechanical ventilation were similar between groups. Conflicting results were observed for acute kidney injury stage II-III, atrial arrhythmias, duration of vasopressors, and ICU length of stay with higher certainty of evidence in favor of vasopressin serving a protective role for these outcomes.

CONCLUSION

Vasopressin was not found to be superior to alternative pressor therapy for any of the included outcomes. Results are limited by mixed methodologies, small overall sample size, and heterogenous populations.

Performance of Severity Indices to Estimate Postoperative Complications of Myocardial Revascularization

Fundamento

Os pacientes em pós-operatório (PO) de cirurgia de revascularização miocárdica (CRM) internados em unidade de terapia intensiva (UTI) apresentam risco de complicações que aumentam o tempo de permanência e a morbimortalidade. Portanto, é fundamental o reconhecimento precoce desses riscos para otimizar estratégias de prevenção e desfecho clínico satisfatório.

Objetivo

Analisar o desempenho de índices de gravidade na predição de complicações em pacientes no PO de CRM durante a permanência na UTI.

Métodos

Estudo transversal, com análise retrospectiva de prontuários eletrônicos de pacientes com idade ≥ 18 anos submetidos à CRM isolada e admitidos na UTI de um hospital cardiológico, em São Paulo, Brasil. As áreas sob as curvas receiver operating characteristic (AUC) com intervalo de confiança de 95% foram analisadas para verificar a acurácia dos índices European System for Cardiac Operative Risk Evaluation (EuroScore), Acute Physiology and Chronic Health Evaluation (APACHE II), Simplified Acute Physiology Score (SAPS II) e Sequential Organ Failure Assessment (SOFA) na predição de complicações.

Resultados

A casuística foi composta por 366 pacientes (64,58±9,42 anos; 75,96% sexo masculino). As complicações identificadas foram respiratórias (24,32%), cardiológicas (19,95%), neurológicas (10,38%), hematológicas (10,38%), infecciosas (6,56%) e renais (3,55%). O APACHE II apresentou satisfatório desempenho para a predição de complicações neurológicas (AUC 0,72) e renais (AUC 0,78).

Conclusão

O APACHE II se destacou na previsão das complicações neurológicas e renais. Nenhum dos índices teve bom desempenho na predição das outras complicações analisadas. Portanto, os índices de gravidade não devem ser utilizados indiscriminadamente com o objetivo de predizer todas as complicações frequentemente apresentadas por pacientes após CRM. (Arq Bras Cardiol. 2020; 115(3):452-459)