Influence of cardiopulmonary bypass set-up and management on clinical outcomes after minimally invasive aortic valve surgery.

INTRODUCTION: Minimally invasive aortic valve replacement (MIAVR) requires changes in cannulation strategy and cardiopulmonary bypass (CPB) management when compared to the conventional approach (CAVR). We aimed at evaluating if these differences could influence perfusion-related quality parameters and impair postoperative outcomes. METHODS: Overall, 339 consecutive patients underwent MIAVR or CAVR between 2014 and 2020 and were analyzed retrospectively. To account for baseline differences, a propensity-matching analysis was performed, obtaining two groups of 97 patients each. RESULTS: MIAVR group had longer CPB time [107 (95-120) vs 95 (86-105) min, p = .003] than CAVR group. Of note, average pump flow rate index [2.4 (2.2-2.5) vs 2.7 (2.4-2.8) l/min/m2, p = .004] was lower in the MIAVR group. Mean arterial pressure was 73 = 9 mmHg vs 62 = 11 mmHg for the MIAVR and CAVR group, respectively (p < .001). Cell-salvaged blood was most commonly used in the MIAVR group (25.8% vs 11.3%, p = .02). Finally, CPB temperature was 32.8°C (32.1-34.8) for MIAVR group vs 34.9°C (33.2-36.1) for the CAVR group (p = .02). Postoperative complications were similar between groups. CONCLUSIONS: In conclusion, despite differences in CPB parameters in patients undergoing CAVR and MIAVR, the incidences of adverse outcomes were similar. However, compared to CAVR, MIAVR was associated with shorter durations of mechanical ventilation and hospital stay as well as less transfusion of blood products.

Normal values of exhaled carbon monoxide in healthy subjects: comparison between two methods of assessment.

BACKGROUND: In a previous study, exhaled carbon monoxide (eCO) has been assessed in healthy non-smokers with a photo acoustic spectrometer Brüel&Kjær 1312. Unexpectedly, values were higher than those reported in literature, which were mostly obtained with electrochemical analysers. This study was aimed to compare eCO values obtained with Brüel&Kjær 1312 and PiCO + Smokerlyzer, a largely utilized electrochemical analyser. METHODS: Thirty-four healthy subjects, 15 non-smokers and 19 smokers, underwent eCO assessment with Brüel&Kjær 1312 and PiCO + Smokerlyzer during a prolonged expiration (15 seconds). Brüel&Kjær 1312 assessed CO concentration 7 and 12 seconds after the beginning of expiration and displayed the mean value. PiCO + Smokerlyzer was utilized according to the manufacturer's recommendations. In vitro, the two devices were tested with standard concentrations of CO in nitrogen (5, 9.9, 20, and 50 ppm), and the time needed by PiCO + Smokerlyzer readings to stabilize was assessed at different gas flows. RESULTS: Both Brüel&Kjær 1312 and PiCO + Smokerlyzer presented very good internal consistency. The values provided were strictly correlated, but at low test concentrations, the Brüel&Kjær 1312 readings were greater than the PiCO + Smokerlyzer, and vice versa. PiCO + Smokerlyzer overestimated the CO standard concentrations at 5 and 9.9 ppm by 20%, while Brüel&Kjær 1312 measures were correct. PiCO + Smokerlyzer readings stabilized in 12 seconds during in vitro tests and in 15 seconds during in vivo measurements, suggesting that the values displayed corresponded to the initial phase of expiration. CONCLUSIONS: Differences between Brüel&Kjær 1312 and PiCO + Smokerlyzer may be explained because Brüel&Kjær 1312 measured CO levels in the middle and at the end of expiration while PiCO + Smokerlyzer assessed them in the initial part of expiration.

Predictors of postoperative atrial fibrillation in patients with coronary artery disease undergoing cardiopulmonary bypass: a possible role for myocardial ischemia and atrial inflammation.

OBJECTIVE: To evaluate the preoperative presence of C-reactive protein (CRP) and troponin T(hs-TnT) in patients with coronary artery disease (CAD) undergoing cardiopulmonary bypass (CPB) in order to better clarify the role of atrial inflammation and/or myocardial ischemia in the development of postoperative atrial fibrillation (POAF). DESIGN: Prospective, nonrandomized study. SETTING: University hospital. PARTICIPANTS: Thirty-eight consecutive ischemic patients admitted to the authors' hospital for CAD undergoing elective on-pump coronary artery bypass grafting (CABG). INTERVENTION: Elective on-pump CABG. MEASUREMENTS AND MAIN RESULTS: Peripheral blood samples were collected from all patients before and 24 hours after CABG to assess high sensitive (hs)-CRP and troponin T (hs-TnT) levels. The patients' heart rhythm was monitored by continuous ECG telemetry. Biopsies from the right atrial appendage were obtained at the beginning of the CABG procedure in order to perform immunohistochemistry for CRP and reverse transcription polymerase chain reaction for CRP mRNA expression. Fourteen patients out of 38 (36%) developed POAF. Atrial CRP was found in 31 patients (82%), 10 with POAF and 21 with sinus rhythm (71% v 87% respectively, p = ns). None of the atrial samples was positive for CRP mRNA. Atrial CRP did not correlate with serum hs-CRP levels and with occurrence of POAF, but with the incidence of diabetes (p = 0.010). Postoperative hs-TnT levels, but not hs-CRP levels, were identified as the only predictor of POAF occurrence (p = 0.016). CONCLUSIONS: In patients undergoing CABG, neither peripheral nor tissue preoperative CRP levels, but only postoperative hs-TnT levels, correlated with POAF, suggesting the primary role of an ischemic trigger of atrial fibrillation.

Extracorporeal membrane oxygenation for resuscitation and cardiac arrest management.

This article reviews the potential application of extracorporeal membrane oxygenation (ECMO) technology to cardiopulmonary resuscitation for in and out-of-hospital cardiac arrest and discusses the current evidence on the subject. The possible strategies for organ protection during ECMO and the concept of ECMO networks are also reviewed.

Influence of intercostal muscles contraction on sonographic evaluation of lung sliding: a physiological study on healthy subjects.

OBJECTIVES: To investigate the following: (a) effects of intercostal muscle contraction on sonographic assessment of lung sliding and (b) inter-rater and intra-observer agreement on sonographic detection of lung sliding and lung pulse. METHODS: We used Valsalva and Muller maneuvers as experimental models in which closed glottis and clipped nose prevent air from entering the lungs, despite sustained intercostal muscles contraction. Twenty-one healthy volunteers underwent bilateral lung ultrasound during tidal breathing, apnea, hyperventilation, and Muller and Valsalva maneuvers. The same expert recorded 420 B-mode clips and 420 M-mode images, independently evaluated for the presence or absence of lung sliding and lung pulse by three raters unaware of the respiratory activity corresponding to each imaging. RESULTS: During Muller and Valsalva maneuvers, lung sliding was certainly recognized in up to 73.0% and up to 68.7% of imaging, respectively, with a slight to fair inter-rater agreement for Muller maneuver and slight to moderate for Valsalva. Lung sliding was unrecognized in up to 42.0% of tidal breathing imaging, and up to 12.5% of hyperventilation imaging, with a slight to fair inter-rater agreement for both. During apnea, interpretation errors for sliding were irrelevant and inter-rater agreement moderate to perfect. Even if intra-observer agreement varied among raters and throughout respiratory patterns, we found it to be higher than inter-rater reliability. CONCLUSIONS: Intercostal muscles contraction produces sonographic artifacts that may simulate lung sliding. Clinical studies are needed to confirm this hypothesis. We found slight to moderate inter-rater agreement and globally moderate to almost perfect intra-observer agreement for lung sliding and lung pulse. TRIAL REGISTRATION: ClinicalTrials.gov registration number. NCT02386696.

Flurbiprofen in the subglottic space to prevent postoperative sore throat after cardiac surgery: A randomized double-blind study.

STUDY OBJECTIVE: Postoperative sore throat (POST) and hoarseness are common complications of tracheal intubation. This study aims to evaluate the efficacy of flurbiprofen administered through the subglottic port of tracheal tubes to prevent POST after cardiac surgery. DESIGN: Single-center, prospective, randomized, double-blind, placebo-controlled trial. SETTING: Tertiary Care Referral University Hospital (Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome). PATIENTS: Included 71 patients undergoing for elective cardiac surgery. Inclusion criteria were (a) age between 50 and 75 years, (b) NYHA class I or II, (c) surgery for myocardial revascularization or valve repair or replacement under cardiopulmonary bypass. INTERVENTION: Patients were double blind randomized to receive flurbiprofen or saline in the subglottic port of the endotracheal tube (groups F and P). The solution was injected ten minutes after tracheal tube placement, ten minutes after ICU admission and ten minutes before tracheal tube removal. MEASUREMENTS: The primary outcome was to assess the effect of topical flurbiprofen administered through the subglottic port of the tracheal tube to prevent post-operative sore throat (POST). The secondary outcomes were the presence of hoarseness safety and patient's subjective satisfaction with their recovery. We did not report any exploratory outcomes. MAIN RESULTS: We analyzed 68 patients, 34 patients in each group. In group F, two patients complained of POST and hoarseness (5.9%), while all controls did. The two groups significantly differed in the severity scores (VAS and TPS for sore throat and HOAR for hoarseness) at all time points. In group P, patients reported mild to moderate symptoms that significantly improved or disappeared 36 h after tracheal tube removal. According to the multivariable model, hoarseness affected women less than men, in the control group (p = 0.002). None of the patients in either group reported any adverse effects. CONCLUSIONS: Repeated administration of flurbiprofen through the subglottic port of tracheal tubes reduced the incidence of sore throat and hoarseness after cardiac surgery without evidence of complications.

Single shot of intravenous iron in cardiac surgery: The ICARUS study.

BACKGROUND: Iron deficiency (ID), with or without anemia, is commonly observed among patients scheduled for cardiac surgery. We investigated if screening ID in the immediate preoperative period and treating ID patients regardless of anemia could reduce perioperative transfusion requirements. METHODS: This is an observational single-center propensity score-matched study including candidates to elective cardiac surgery prospectively and retrospectively enrolled. Prospectively enrolled patients were screened for ID at hospital admission: if ferritin was ≤100 µg/L or ≤ 300 µg/L with transferrin saturation index ≤20% they received intravenous ferric carboxymaltose, B12-vitamin, and folic acid. A retrospective series of patients not screened for ID and matched for gender, type of surgery, BMI, Goudie transfusion risk score, hemoglobin level, and red blood cell (RBC) indices, served as controls. The primary outcome was the proportion of patients requiring ≤1 packed RBC (pRBC) unit within day 7 or discharge The main secondary outcomes were intraoperative and postoperative pRBC transfusions, duration of hospitalization, and cost-effectiveness of ID screening and treatment. RESULTS: We included 479 prospective and 833 retrospective cases: 442 patients screened for ID and 442 matched controls with unknown iron status were analyzed. ID was observed in 196 patients (44.3%) and iron was administered 1 day (IQR 1-2) before surgery. Overall, 76.9% of patients in the prospective group and 69.7% of controls received ≤1 pRBC transfusion (p = 0.014). The risk for multiple transfusions was lower in patients screened for ID (OR 0.689, 95% CI 0.510-0.930). Despite similar Hb levels at day 7, patients in the prospective group received fewer postoperative pRBC transfusions (p < 0.001) and had a shorter hospital length of stay (p < 0.001). Globally, hospitalization costs were lower in patients screened and treated for ID. CONCLUSIONS: Short-term pre-operative iron therapy is associated with a reduction in postoperative transfusions in anemic and non-anemic ID cardiac surgery patients and has a favorable impact on hospitalization costs. CLINICAL TRIAL REGISTRATION: NCT04744181.

Postoperative Intensive Care Management of Aortic Repair.

Vascular surgery patients have multiple comorbidities and are at high risk for perioperative complications. Aortic repair surgery has greatly evolved in recent years, with an increasing predominance of endovascular techniques (EVAR). The incidence of cardiac complications is significantly reduced with endovascular repair, but high-risk patients require postoperative ST-segment monitoring. Open aortic repair may portend a prohibitive risk of respiratory complications that could be a contraindication for surgery. This risk is greatly reduced in the case of an endovascular approach, and general anesthesia should be avoided whenever possible in the case of endovascular repair. Preoperative renal function and postoperative kidney injury are powerful determinants of short- and long-term outcome, so that preoperative risk stratification and secondary prevention are critical tasks. Intraoperative renal protection with selective renal and distal aortic perfusion is essential during open repair. EVAR has lower rates of postoperative renal failure compared to open repair, with approximately half the risk for acute kidney injury (AKI) and one-third of the risk of hemodialysis requirement. Spinal cord ischemia used to be the most distinctive and feared complication of aortic repair. The risk has significantly decreased since the beginning of aortic surgery, with advances in surgical technique and spinal protection protocols, and is lower with endovascular repair. Endovascular repair avoids extensive aortic dissection and aortic cross-clamping and is generally associated with reduced blood loss and less coagulopathy. The intensive care physician must be aware that aortic repair surgery has an impact on every organ system, and the importance of early recognition of organ failure cannot be overemphasized.

Clinical Impact of Heart Team Decisions for Patients With Complex Valvular Heart Disease: A Large, Single-Center Experience.

Background A multidisciplinary approach might be pivotal for the management of patients with valvular heart disease (VHD), but clinical outcome data are lacking. Methods and Results At our institution, since 2014, internal guidelines recommended heart team consultations for patients with VHD. The clinical/echocardiographic characteristics, treatment recommendations, performed treatment, and early clinical outcomes of consecutive, hospitalized patients with VHD undergoing heart team evaluation were collected. Surgical risk was prospectively assessed by the EuroSCORE II and STS-PROM. The primary end point of the study was early mortality. A total of 1004 patients with VHD with high clinical complexity (mean age, 75 years; mean EuroSCORE II, 9.4%; mean STS-PROM, 5.6%; 48% ischemic heart disease; 29% chronic kidney disease, 9% oncologic/hematologic diseases) were enrolled. The heart team recommended an interventional treatment for 807 (80%) patients and conservative management for 197 (20%) patients. Management crossovers occurred in only 5% of patients. The recommended intervention was cardiac surgery for 230 (23%) patients, percutaneous treatment in 516 (51%) patients, and hybrid treatment in 61 (6%) patients. Early mortality occurred in 24 patients (2.4%) and was independently predicted by aortic stenosis, left ventricular ejection fraction, pulmonary artery systolic pressure, and conservative management recommendation. In patients referred to treatment, observed early mortality (1.7%) was significantly lower (P<0.001) than expected on the bases of both the STS-PROM (5.2%) and EuroSCORE II (9.7%). Conclusions Within the limitations of its single-center and observational design, the present study suggests that heart team-based management of patients with complex VHD is feasible and allows referral to a wide spectrum of interventions with promising early clinical results.

Sonographic assessment of abdominal vein dimensional and hemodynamic changes induced in human volunteers by a model of abdominal hypertension.

OBJECTIVE: In patients affected by intra-abdominal hypertension, bladder or gastric pressure measurement may be usefully integrated by ultrasounds in order to detect early hemodynamic impairment. The purpose of this study was to search for changes in abdominal vein size and flow induced by intra-abdominal hypertension. DESIGN: Physiologic study. SETTING: Postoperative intensive care unit of a university hospital. SUBJECTS: Sixteen healthy volunteers. INTERVENTIONS: Four echographic assessments of vessel sizes and blood velocities were randomly performed in the following settings: 1) baseline, 2) intra-abdominal hypertension simulated by a tight pelvic stabilizer around the waist, 3) noninvasive ventilation with a facial mask, and 4) intra-abdominal hypertension plus noninvasive ventilation. MEASUREMENTS AND MAIN RESULTS: The model of intra-abdominal hypertension was validated in eight subjects by measuring gastric pressure. During intra-abdominal hypertension, 1) the inferior vena cava was compressed (significant decrease of both anteroposterior and lateral diameters) and deformed (decreased anteroposterior/lateral diameter ratio), and deformation, but not compression, was attenuated by noninvasive ventilation associated with intra-abdominal hypertension; 2) the portal vein was also compressed (decreased diameter); and 3) blood velocities did not change significantly in the inferior vena cava, portal vein, right suprahepatic vein, or right external iliac vein. In the receiver operating characteristic curve analysis, an inferior vena cava section area (normalized for body surface) of lower than 1 cm²/m² discriminated between intra-abdominal hypertension presence and absence with a sensitivity of 65.6% and a specificity of 87.5% (p = .0001). Noninvasive ventilation alone did not significantly affect vein sizes and velocities. The resistive index, calculated by pulse wave Doppler signal from segmental branches of the right renal artery, increased slightly, but significantly, during intra-abdominal hypertension alone, suggesting an increase of intrarenal pressure. CONCLUSIONS: Simulated intra-abdominal hypertension was associated with decreased inferior vena cava section area and increased resistive index in renal arteries. Further studies are now needed to investigate whether these changes may be of value to integrate bladder or gastric pressure measurement in clinical practice.

Minimally Invasive Aortic Valve Surgery in Octogenarians: Reliable Option or Fallback Solution?

OBJECTIVE: Aortic valve disease is more and more common in western countries. While percutaneous approaches should be preferred in older adults, previous reports have shown good outcomes after surgery. Moreover, advantages of minimally invasive approaches may be valuable for octogenarians. We sought to compare outcomes of conventional aortic valve replacement (CAVR) versus minimally invasive aortic valve replacement (MIAVR) in octogenarians. METHODS: We retrospectively collected data of 75 consecutive octogenarians who underwent primary, elective, isolated aortic valve surgery through conventional approach (41 patients, group CAVR) or partial upper sternotomy (34 patients, group MIAVR). RESULTS: Mean age was 81.9 ± 0.9 and 82.3 ± 1.1 years in CAVR and MIAVR patients, respectively (P = 0.09). MIAVR patients had lower 24-hour chest drain output (353.4 ± 207.1 vs 501.7 ± 229.9 mL, P < 0.01), shorter mechanical ventilation (9.6 ± 2.4 vs 11.3 ± 2.3 hours, P < 0.01), lower need for blood transfusions (35.3% vs 63.4%, P = 0.02), and shorter hospital stay (6.8 ± 1.6 vs 8.3 ± 4.3 days, P < 0.01). Thirty-day mortality was zero in both groups. Survival at 1, 3, and 5 years was 89.9%, 80%, and 47%, respectively, in the CAVR group, and 93.2%, 82.4%, and 61.8% in the MIAVR group, with no statistically significant differences (log-rank test, P = 0.35). CONCLUSIONS: Aortic valve surgery in older patients provided excellent results, as long as appropriate candidates were selected. MIAVR was associated with shorter mechanical ventilation, reduced blood transfusions, and reduced hospitalization length, without affecting perioperative complications or mid-term survival.

Correction to: A year in review in Minerva Anestesiologica 2019. Critical care.

This corrects the article DOI:10.23736/S0375-9393.20.14384-0.

Effects of acute hypoventilation and hyperventilation on exhaled carbon monoxide measurement in healthy volunteers.

BACKGROUND: High levels of exhaled carbon monoxide (eCO) are a marker of airway or lung inflammation. We investigated whether hypo- or hyperventilation can affect measured values. METHODS: Ten healthy volunteers were trained to achieve sustained end-tidal CO2 (etCO(2)) concentrations of 30 (hyperventilation), 40 (normoventilation), and 50 mmHg (hypoventilation). As soon as target etCO(2) values were achieved for 120 sec, exhaled breath was analyzed for eCO with a photoacoustic spectrometer. At etCO(2) values of 30 and 40 mmHg exhaled breath was sampled both after a deep inspiration and after a normal one. All measurements were performed in two different environmental conditions: A) ambient CO concentration = 0.8 ppm and B) ambient CO concentration = 1.7 ppm. RESULTS: During normoventilation, eCO mean (standard deviation) was 11.5 (0.8) ppm; it decreased to 10.3 (0.8) ppm during hyperventilation (p < 0.01) and increased to 11.9 (0.8) ppm during hypoventilation (p < 0.01). eCO changes were less pronounced than the correspondent etCO(2) changes (hyperventilation: 10% Vs 25% decrease; hypoventilation 3% Vs 25% increase). Taking a deep inspiration before breath sampling was associated with lower eCO values (p < 0.01), while environmental CO levels did not affect eCO measurement. CONCLUSIONS: eCO measurements should not be performed during marked acute hyperventilation, like that induced in this study, but the influence of less pronounced hyperventilation or of hypoventilation is probably negligible in clinical practice.

Size and shape of the inferior vena cava before and after a fluid challenge: a pilot study.

BACKGROUND: Recent meta-analyses failed to support the reliability of ultrasound assessment of the inferior vena cava (IVC) to predict fluid responsiveness. However, the techniques utilized were heterogeneous. We hypothesized that the variability of the elliptic section and caliber of the IVC along its course may influence ultrasound evaluation. Therefore, we investigated IVC size and shape at four levels, before and after a fluid challenge. METHODS: Twenty mechanically-ventilated adult patients who received a fluid challenge after cardiac surgery were enrolled. They were regarded as responders if the cardiac index increased more than 15%. Before and after the fluid challenge, IVC anteroposterior (AP) and lateral (LA) diameters, the flat ratio, and the distensibility index were assessed by ultrasound just above the iliac veins, at the confluence of the renal veins, before the confluence of the hepatic veins (where blood flow velocity was also measured), and after it. RESULTS: At all levels, IVC section was elliptical, so that IVC diameters varied between a minimum and a maximum according to the measurement angle. Such interval increased in correspondence of the renal veins, where IVC section was more eccentric. The distensibility index was higher when assessed on AP diameters. After the fluid challenge, non-responders showed a diffuse increase of AP diameters, whereas responders showed an increase of blood velocity before the confluence of the hepatic veins. CONCLUSIONS: The elliptic section should be considered when assessing IVC size. AP diameters are shorter and more affected by the respiratory cycle. After a fluid challenge, an increase of blood velocity associated with unchanged AP diameters may suggest fluid responsiveness.

A modified intracavitary electrocardiographic method for detecting the location of the tip of central venous catheters in atrial fibrillation patients.

INTRODUCTION: The intracavitary electrocardiographic method is recommended for assessing the location of the tip of central venous catheter when there is an identifiable P wave. Previous reports suggested that intracavitary electrocardiographic method might also be applied to patients with atrial fibrillation, considering the so-called f waves as a surrogate of the P wave. METHODS: We studied 18 atrial fibrillation patients requiring simultaneously a central venous catheter and a trans-esophageal echocardiography. An intracavitary electrocardiographic trace was recorded with the catheter tip in three different positions defined by trans-esophageal echocardiography imaging: in the superior vena cava, 2 cm above the cavo-atrial junction; at the cavo-atrial junction; and in the right atrium, 2 cm below the cavo-atrial junction. Three different criteria of measurement of the f wave pattern in the TQ tract were used: the mean height of f waves (method A); the height of the highest f wave (method B); the difference between the highest positive peak and the lowest negative peak (method C). RESULTS: There were no complications. With the tip placed at the cavo-atrial junction, the mean value of the f waves was significantly higher than in the other two positions. All three methods were effective in discriminating the tip position at the cavo-atrial junction, though method B proved to be the most accurate. CONCLUSION: A modified intracavitary electrocardiographic technique can be safely used for detecting the location of the tip of central venous catheters in atrial fibrillation patients: the highest activity of the f waves is an accurate indicator of the location of the tip at the cavo-atrial junction.

Clinical guidelines for perioperative hemodynamic management of non cardiac surgical adult patients.

Perioperative hemodynamic management, through monitoring and intervention on physiological parameters to improve cardiac output and oxygen delivery (goal-directed therapy, GDT), may improve outcome. However, an Italian survey has revealed that hemodynamic protocols are applied by only 29.1% of anesthesiologists. Aim of this paper is to provide clinical guidelines for a rationale use of perioperative hemodynamic management in non cardiac surgical adult patients, oriented for Italy and updated with most recent studies. Guidelines were elaborated according to NICE (National Institute for Health and Care Excellence) and GRADE system (Grading of Recommendations of Assessment Development and Evaluations). Key questions were formulated according to PICO system (Population, Intervention, Comparators, Outcome). Guidelines and systematic reviews were identified on main research databases and strategy was updated to June 2018. There is not enough good quality evidence to support the adoption of a GDT protocol in order to reduce mortality, although it may be useful in high risk patients. Perioperative GDT protocol to guide fluid therapy is recommended to reduce morbidity. Continuous monitoring of arterial pressure may help to identify short periods of hemodynamic instability and hypotension. Fluid strategy should aim to a near zero balance in normovolemic patients at the beginning of surgery, and a slight positive fluid balance may be allowed to protect renal function. Drugs such as inotropes, vasocostrictors, and vasodilatator should be used only when fluids alone are not sufficient to optimize hemodynamics. Perioperative GDT protocols are associated with a reduction in costs, although no economic study has been performed in Italy.