Combined Renal-Pulmonary Extracorporeal Support with Low Blood Flow Techniques: A Retrospective Observational Study (CICERO Study).

BACKGROUND: Critically ill patients with acute respiratory failure frequently present concomitant lung and kidney injury, within a multiorgan failure condition due to local and systemic mediators. To face this issue, extracorporeal carbon dioxide removal (ECCO2R) systems have been integrated into continuous renal replacement therapy (CRRT) platforms to provide a combined organ support, with efficient clearance of CO2 with very low extracorporeal blood flows (<400 mL/min). OBJECTIVES: To evaluate efficacy and safety of combined ECCO2R-CRRT support with PrismaLung®-Prismaflex® in patients affected by hypercapnic respiratory acidosis associated with AKI in a second level intensive care unit. METHODS: We carried out a retrospective observational study enrolling patients submitted to PrismaLung®-Prismaflex® due to mild to moderate acute respiratory distress syndrome (ARDS) or acute exacerbation of chronic obstructive pulmonary disease (aeCOPD). The primary endpoints were the shift to protective ventilation and extubation of mechanically ventilated patients and the shift to invasive mechanical ventilation of patients receiving noninvasive ventilation (NIV). Clinical-laboratoristic data and operational characteristics of ECCO2R-CRRT were recorded. RESULTS: Overall, 12/17 patients on mechanical ventilation shifted to protective ventilation, CO2 clearance was satisfactorily maintained during the whole observational period, and pH was rapidly corrected. Treatment prevented NIV failure in 4 out of 5 patients. No treatment-related complications were recorded. CONCLUSION: ECCO2R-CRRT was effective and safe in patients with aeCOPD and ARDS associated with AKI.

Preoperative Sucrosomial Iron Supplementation Increases Haemoglobin and Reduces Transfusion Requirements in Elective Heart Surgery Patients: A Prospective Randomized Study.

BACKGROUND: Low preoperative haemoglobin is frequently observed in heart surgery patients and is associated with a significant decrease in haemoglobin between post-operative days 2 and 3, known as haemoglobin drift. Overall, these patients tend to receive many RBC transfusions. Since iron homeostasis is often impaired in these patients, restoration of iron availability might override iron-restricted erythropoiesis. However, reduced tolerance to oral iron salts has limited this strategy to intravenous iron administration. STUDY DESIGN AND METHODS: The purpose of this study was to assess whether preoperative supplementation with oral sucrosomial iron, a new iron-delivery technology with improved tolerance and bioavailability, might be an effective strategy for this patient population. One thousand consecutive patients were randomized and received either a one-month course of sucrosomial iron (60 mg/day) or no treatment prior to elective heart surgery at a single high-volume centre (ClinicalTrials.gov NCT03560687). Primary end-points were haemoglobin concentration on the day of hospital admittance and number of blood transfusions. Secondary end-points were haemoglobin drift, tolerance of treatment and cost-effectiveness of sucrosomial iron administration. RESULTS: Baseline haemoglobin in the treatment group was higher (by 0.67 g/dL; p<0.001) than that in the control group. The percentage of patients in the treatment group who required transfusion (35.4%) was half that in the control group (64.6%). The average number of transfused units per operation was 0.95 vs. 2.03 in the treatment and control groups, respectively. Haemoglobin drift was substantially similar in the two groups, and the tolerability of treatment was excellent (98%). The overall cost of treatment was 156 Euros less in the treatment group, expressed as a raw cost of transfusion. CONCLUSION: In elective heart surgery, routine preoperative sucrosomial iron administration seems to be a safe, well-tolerated and cost-effective strategy to increase preoperative haemoglobin and reduce the need for allogeneic blood transfusions.

Continuous Renal Replacement Therapy with the Adsorbing Filter oXiris in Septic Patients: A Case Series.

BACKGROUND: Extracorporeal treatment may be useful during sepsis, but definitive recommendations are lacking. Aim of this study is to review retrospectively the medical records of septic patients submitted to continuous renal replacement therapy (CRRT) with the adsorbing membrane oXiris and evaluate (1) the safety of the device, (2) the cardiorenal response, and (3) the immunological response. MATERIALS AND METHODS: The medical records of 60 septic patients submitted to CRRT with the membrane oXiris from April 2011 to December 2018 have been reviewed. The adsorbing membrane oXiris® (Baxter, IL, USA) was used through a Prisma plataform (Prismaflex - Baxter, IL, USA). At basal time (T0), at 24 h (T1), and at the end of the treatment (T2) were analyzed the clinical data, the cytokines, and the time course of endotoxin. RESULTS: Sixty patients were included in the study. In total, 85% of patients had acute kidney injury (AKI). Every CRRT treatment was of 72 ± 13 h, with the consumption of 3.2 ± 1 filters. No AE events were reported. The main cardiorenal and respiratory parameters improved with a decrease of the noradrenaline dosage. Cytokines, procalcitonin, and endotoxin activity assay decreased too. SOFA total improved from 12.4 ± 2 to 9 ± 2. CONCLUSION: In sepsis/septic shock patients with AKI, CRRT with the adsorbing membrane oXiris may be safe and improves the cardiorenal - function and the clinical condition. The effect on cytokines and endotoxin may explain in part these results. A RCT is warranted to confirm these data.

Sepsis Management with a Blood Purification Membrane: European Experience.

BACKGROUND: Septic shock is a leading cause of acute kidney injury (AKI). Endotoxins and cytokine levels are associated with the occurrence and severity of AKI, and different blood purification devices are available to remove them from circulation. One such device, oXiris, is a hollow-fibre purification filter that clears both endotoxins and cytokines. Due to limited evidence, clinical use of this device is not currently advocated in guidelines. However, clinics do regularly use this device, and there is a critical need for guidance on the application of it in sepsis with and without AKI. METHOD: A modified Delphi-based method was used to collate -European experts' views on the indication(s), initiation and discontinuation criteria and success measures for oXiris. RESULTS: A panel of 14 participants was selected based on known clinical expertise in the areas of critical care and sepsis management, as well as their experience of using the oXiris blood purification device. The participants used different criteria to initiate treatment with oXiris in sepsis patients with and without AKI. Septic shock with AKI was the priority patient population, with oXiris used to rapidly improve haemodynamic parameters. Achieving haemodynamic stability within 72 h was a key factor for determining treatment success. CONCLUSION: In the absence of established guidelines, users of hollow-fibre purification devices such as oXiris may benefit from standardised approaches to selecting patients and initiating and terminating treatment, as well as measuring success. Further evidence in the form of randomised clinical trials is urgently required.

Prospective Randomized Clinical Trial of HEMOPATCH Topical Sealant in Cardiac Surgery.

OBJECTIVE: Hemostasis is a critical component of all surgical procedures and especially cardiac surgery. In addition to traditional means, topical hemostatic agents have been reported to be extremely effective in terminating bleeding during cardiac procedures. We compared a hemostatic matrix sealant agent (HEMOPATCH Baxter Healthcare Corporation, Deerfield, IL) with alternative topical hemostatic treatment in patients undergoing ascending aorta surgery with moderate bleeding. MATERIALS AND METHODS: Following sample size calculation, in a prospective randomized study design, 85 patients were treated with HEMOPATCH matrix sealant and 85 patients received alternative treatment (dry or wet gauze compression or similar [control group]). The primary outcome measure was the percentage of patients with successful hemostasis within three minutes of HEMOPATCH or traditional treatment application. Other study outcome measures were postoperative blood loss and the rate of transfusion of blood products. RESULTS: A statistically higher rate of successful hemostasis within three minutes was observed in the HEMOPATCH group (97.6% [83/85] vs. 65.8% [56/85] in the control group; p< 0.001). The percentages of patients with postoperative bleeding and the rate of transfusion were lower in the HEMOPATCH group than in the control group. CONCLUSIONS: The use of HEMOPATCH is effective in terminating bleeding in patients undergoing ascending aorta cardiac procedures. Fewer patients treated with HEMOPATCH required blood transfusion. The cost-utility profile of HEMOPATCH should be addressed in dedicated trials.

A single dose of erythropoietin reduces perioperative transfusions in cardiac surgery: results of a prospective single-blind randomized controlled trial.

BACKGROUND: We conducted a prospective single-blind randomized study to assess whether a single 80,000 IU dose of human recombinant erythropoietin (HRE), given just 2 days before cardiac surgery, could be effective in reducing perioperative allogeneic red blood cell transfusion (aRBCt). STUDY DESIGN AND METHODS: Six-hundred patients presenting with preoperative hemoglobin (Hb) level of not more than 14.5 g/dL were randomly assigned to either HRE or control. The primary endpoint was the incidence of perioperative aRBCt. The secondary endpoints were mortality and the incidence of adverse events in the first 45 days after surgery, Hb level on Postoperative Day 4, and number of units of RBC transfusions in the first 4 days after surgery. RESULTS: A total of 17% (HRE) versus 39% (control) required transfusion (relative risk, 0.436; p<0.0005). After baseline Hb was controlled for, there was no difference in the incidence of aRBCt between HRE (0%) and control (3.5%) among the patients with baseline Hb of 13.0 g/dL or more, which included the nonanemic fraction of the study population. The mean (range) Hb level on Postoperative Day 4 was 10.2 (9.9-10.6) g/dL (HRE) versus 8.7 (8.5-9.2) g/dL (control; p<0.0005). The distribution of number of units transfused was shifted toward fewer units in HRE (p<0.0005). The all-cause mortality at 45 days was 3.00% (HRE) versus 3.33% (control). The 45-day adverse event rate was 4.33% (HRE) versus 5.67% (control; both p=NS). CONCLUSION: In anemic patients (Hb<13 g/dL), a single high dose of HRE administered 2 days before cardiac surgery is effective in reducing the incidence of aRBCt without increasing adverse events.

Renal replacement therapy in acute kidney injury: controversy and consensus.

Renal replacement therapies (RRTs) represent a cornerstone in the management of severe acute kidney injury. This area of intensive care and nephrology has undergone significant improvement and evolution in recent years. Continuous RRTs have been a major focus of new technological and treatment strategies. RRT is being used increasingly in the intensive care unit, not only for renal indications but also for other organ-supportive strategies. Several aspects related to RRT are now well established, but others remain controversial. In this review, we review the available RRT modalities, covering technical and clinical aspects. We discuss several controversial issues, provide some practical recommendations, and where possible suggest a research agenda for the future.

Expert perspectives on ECCO2R for acute hypoxemic respiratory failure: consensus of a 2022 European roundtable meeting.

BACKGROUND: By controlling hypercapnia, respiratory acidosis, and associated consequences, extracorporeal CO2 removal (ECCO2R) has the potential to facilitate ultra-protective lung ventilation (UPLV) strategies and to decrease injury from mechanical ventilation. We convened a meeting of European intensivists and nephrologists and used a modified Delphi process to provide updated insights into the role of ECCO2R in acute respiratory distress syndrome (ARDS) and to identify recommendations for a future randomized controlled trial. RESULTS: The group agreed that lung protective ventilation and UPLV should have distinct definitions, with UPLV primarily defined by a tidal volume (VT) of 4-6 mL/kg predicted body weight with a driving pressure (ΔP) ≤ 14-15 cmH2O. Fourteen (93%) participants agreed that ECCO2R would be needed in the majority of patients to implement UPLV. Furthermore, 10 participants (majority, 63%) would select patients with PaO2:FiO2 > 100 mmHg (> 13.3 kPa) and 14 (consensus, 88%) would select patients with a ventilatory ratio of > 2.5-3. A minimum CO2 removal rate of 80 mL/min delivered by continuous renal support machines was suggested (11/14 participants, 79%) for this objective, using a short, double-lumen catheter inserted into the right internal jugular vein as the preferred vascular access. Of the participants, 14/15 (93%, consensus) stated that a new randomized trial of ECCO2R is needed in patients with ARDS. A ΔP of ≥ 14-15 cmH2O was suggested by 12/14 participants (86%) as the primary inclusion criterion. CONCLUSIONS: ECCO2R may facilitate UPLV with lower volume and pressures provided by the ventilator, while controlling respiratory acidosis. Since recent European Society of Intensive Care Medicine guidelines on ARDS recommended against the use of ECCO2R for the treatment of ARDS outside of randomized controlled trials, new trials of ECCO2R are urgently needed, with a ΔP of ≥ 14-15 cmH2O suggested as the primary inclusion criterion.

Benefits of pre-operative oral Sucrosomial® iron supplementation in cardiac surgery: influence of patient's baseline hemoglobin and gender.

BACKGROUND: The prevalence of low pre-operative hemoglobin (Hb) among cardiac surgery patients is high. As iron homeostasis is often impaired in these patients, restoration of iron availability might over-ride iron-restricted erythropoiesis. This post-hoc analysis of a previously published, large, randomized clinical trial (ClincalTrials.gov NCT03560687; n=1,000) assesses which sub-cohort of patients benefits the most from pre-operative Hb optimization with oral Sucrosomial® iron. MATERIALS AND METHODS: Patients without baseline Hb (n=349) or receiving >5 red blood cell units (n=57) were excluded from the study. Data from the remaining 594 were reanalyzed according to treatment, baseline anemia (Hb <13 g/dL) or gender. Patients (pt) received a one-month course of 60 mg/day Sucrosomial® iron (Iron group, n=309) or routine care (Control group, n=285) prior to elective cardiac surgery. Main end-point variables were increase in Hb from randomization to hospital admission, transfusion requirements, and cost-effectiveness of Sucrosomial® iron administration. RESULTS: At hospital admission, Hb had increased 0.7 g/dL and 0.1 g/dL, for Iron and Control groups, respectively (p<0.001), with no gender-related differences, leading to a decrease in transfusion rate (30 vs 59%, respectively; p<0.001) and transfusion index (0.5 units/patient vs 1.2 units/pt, respectively; p<0.001). Sucrosomial® iron administration was well-tolerated, and yielded cost-savings of €92/pt (p<0.001), particularly in those presenting with baseline Hb <13 g/dL. CONCLUSIONS: This post-hoc analysis confirms pre-operative Sucrosomial® iron administration is a safe and cost-effective strategy to increase preoperative Hb and decrease transfusion requirements in elective cardiac surgery, especially in those anemic at baseline.

Emergency treatment of a salmonella-infected abdominal aortic aneurysm associated with spondylodiscitis.

AIM: To report surgical treatment of a ruptured abdominal aortic aneurysm (AAA) associated with spondylodiscitis due to Salmonella in emergency setting. CASE REPORT: A 69-year-old male with an history of hypertension, presented with a ruptured AAA infected by nontyphoidal Salmonella (type H), associated with spondylodiscitis. Patient underwent an emergency operation consisting in surgical debridment of infected tissue and aortic replacement with a prosthetic Dacron graft impregnated with Gentamycine. The postoperative course was uneventful and the patient was discharged at day 20 after the index procedure in good clinical condition. antimicrobial therapy was continued for 8 weeks. A CT scan and nuclear medicine studies performed two months later demonstrated minimal sign of residual aortitis. A CT scan 21 months after the procedure showed complete anatomic resolution of the disease. CONCLUSIONS: A rare but increasing number of aneurysms as a consequence of Salmonellosis can be observed with a high rate of morbidity and mortality, mainly in patients with a concurrent infection of the spine and paravertebral tissue. Combined antimicrobial therapy and one-stage surgical treatment can be associated with good outcome. KEYWORDS: Abdominal aorta aneurysm, Mycotic aortic aneurysms, Salmonellosis, Spondylodiscitis.

Kinetics of serum procalcitonin in patients with acute mesenteric ischemia and bowel infarction after cardiac surgery.

BACKGROUND: The present study reported perioperative changes in PCT levels occurring in cardiac patients with acute mesenteric ischemia (AMI) undergoing laparotomy. The aim of this study was to demonstrate that PCT kinetics may confirm the presence of AMI after cardiac surgery, distinguishing between bowel infarction and diffuse ischemia. METHODS: PCT values from adult patients undergoing laparotomy for AMI after elective or urgent cardiac surgery (January 2010-December 2019) were determined at the ICU admission after cardiac surgery, 24 hours later and at the onset of clinical symptoms. Patients affected by diffuse intestinal ischemia with no need for bowel resection were allocated to Group A (N. 8), patients presented with intestinal necrosis requiring small or large bowel resection were allocated to Group B (N. 12). RESULTS: At the beginning of the abdominal symptoms, PCT levels increased in both groups, compared to those immediately after cardiac surgery. The PCT increasing resulted much more evident in patients presenting with intestinal necrosis in Group B (20.65 ng/mL [IQR8.47-34.5] vs. 4.31 ng/mL [IQR 8.47-34.5], P<0.05), rather than in those with diffuse ischemia in Group A (13.25 ng/mL [IQR 5.97-27.65] vs. 10.4 ng/mL [IQR 3.68-14.05], P=0.260). This trend was confirmed in the subgroup of patients undergoing CVVHD and in patients who experience AMI recurrence. CONCLUSIONS: Increasing PCT values after cardiac surgery are proportional to the severity of wall ischemia and high levels of PCT are predictive of intestinal necrosis. Routine PCT monitoring after cardiac surgery should be considered extremely useful in suggesting the possibility of abdominal complications, alerting medical staff to the need of prompt treatment.

Towards a better comprehension of acute mesenteric ischemia after cardiac surgery. An analysis of 33 patients.

BACKGROUND: Acute mesenteric ischemia (AMI) after cardiac surgery is a rare but serious complication associated to high mortality. The time of onset is the key point to correctly evaluate the clinical scenarios. METHODS: Data from adult patients who underwent laparotomy for AMI after elective or urgent cardiac surgery were reviewed (January 2005 - December 2019) to report their anatomoclinical features in relationship to time of onset. Early events (within 48 hours) were allocated to Group 1, whereas late onsets were allocated to Group 2. RESULTS: The incidence of risk factors for non occlusive mesenteric ischemia was higher in Group 1 (chronic renal failure 80% vs 38.8%, P <0.05, use of inotropes 60% vs 5.5%, P <0.01, early oligo-anuria requiring CRRT 80% vs 16.6%, P <0.01, prolonged ventilation 46.6% vs 5.5%, P <0.05), where a significative occurrence of postoperative de novo atrial fibrillation was noted in Group 2 (55% vs 5.5%, P <0.01). The number of patients who required bowel resection was proportionally higher in the Group 2. CONCLUSIONS: Two well distinct categories of AMI after cardiac surgery can be classified. The first consists of patients with well-known risk factors developing ischemia as a result of severe visceral hypoperfusion The second consists of patients with low comorbidity who experience late AMI as a consequence of "trigger events", mainly de novo atrial fibrillation. This classification may be useful to better alert the medical staff to the possibility of bowel ischemia at any time after cardiac surgery, promoting early diagnosis and treatment. KEY WORDS: Mesenteric ischemia, Cardiovascular pathology.

Mechanical ventilation affects inflammatory mediators in patients undergoing cardiopulmonary bypass for cardiac surgery: a randomized clinical trial.

OBJECTIVES: Respiratory support for patients recovering from cardiopulmonary bypass and cardiac surgery uses large tidal volumes and a minimal level of positive end-expiratory pressure. Recent data indicate that these ventilator settings might cause pulmonary and systemic inflammation in patients with acute lung injury. We examined the hypothesis that high tidal volumes and low levels of positive end-expiratory pressure might worsen the inflammatory response associated to cardiopulmonary bypass. METHODS: Forty patients undergoing elective coronary artery bypass were randomized to be ventilated after cardiopulmonary bypass disconnection with high tidal volume/low positive end-expiratory pressure (10-12 mL/kg and 2-3 cm H2O, respectively) or low tidal volume/high positive end-expiratory pressure (8 mL/kg and 10 cm H2O, respectively). Interleukin 6 and interleukin 8 levels were measured in the bronchoalveolar lavage fluid and plasma. Samples were taken before sternotomy (time 0), immediately after cardiopulmonary bypass separation (time 1), and after 6 hours of mechanical ventilation (time 2). RESULTS: Interleukin 6 and interleukin 8 levels in the bronchoalveolar lavage fluid and plasma significantly increased at time 1 in both groups but further increased at time 2 only in patients ventilated with high tidal volume/low positive end-expiratory pressure. Interleukin 6 and interleukin 8 levels in the bronchoalveolar lavage fluid and in the plasma at time 2 were higher with high tidal volume/low positive end-expiratory pressure than with low tidal volume/high positive end-expiratory pressure. CONCLUSION: Mechanical ventilation might be a cofactor able to influence the inflammatory response after cardiac surgery.

Acute mesenteric ischemia after cardiac surgery. Role of the abdominal compartment syndrome treatment.

BACKGROUND: The management of abdominal compartment syndrome (ACS) has been included as a standard of care in our therapeutic algorithm after diagnosis of acute mesentheric ischemia (AMI), following cardiac surgery. This report is an updated review of our results compared to previous experience. MATERIALS AND METHODS: A retrospective, observational, cohort study on a series of 26 patients (20 males, 6 females, mean age 75.2 years, min 64, max 83) who developed AMI, out of 7.719 patients undergoing cardiac operations (january 2005 - December 2014). The initial treatment consisted of laparotomy with abdominal decompression and temporary abdominal closure, performing visceral resections just in case of gangrenous tracts and providing for a "secondlook" during the variable period of resuscitation and vacuum assisted dressing. RESULTS: A non-occlusive mesentheric ischemia with diffuse visceral underperfusion was confirmed in every case. Temporary abdominal closure was applied to treat ACS in every case, 13 patients required associated resection of gangrenous tracts (50%). Seventeen patients died following first operation as a consequence of multiple organ failure (65.4%). Nine patients survived (34.6%) and underwent re-establishment of intestinal continuity and definitive closure of abdominal wall within 30 DAYS. DISCUSSION AND CONCLUSIONS: AMI occuring after cardiac surgery is associated with an increase of intra-abdominal pressure and subsequent ACS. Basing on this case series, an early ACS treatment using open abdomen techniques may be results in a better outcome of critically injured cardiac patients. These results compared favourably with literature experiences (mortality rate > 85%). KEY WORDS: Abdominal compartment syndrome, Acute mesentheric ischemia, Cardiac surgery.

Epicardial ganglionated plexus stimulation decreases postoperative inflammatory response in humans.

BACKGROUND: Surgical cardiac revascularization produces a high degree of systemic inflammation and the secretion of several cytokines. Intensive postoperative inflammation may increase the incidence of postoperative atrial fibrillation and favor organ dysfunctions. No data documenting the anti-inflammatory properties of epicardial vagal ganglionated plexus stimulation are available. OBJECTIVE: To verify the feasibility and safety of postoperative inferior vena cava-inferior atrial ganglionated plexus (IVC-IAGP) burst stimulation and the effectiveness of this approach in reducing serum levels of inflammatory cytokines. METHODS: In 27 patients who were candidates for off-pump surgical revascularization, the IVC-IAGP was located during surgery, a temporary wire was inserted, and a negative atrioventricular node dromotropic effect was obtained in 20 patients on applying high-frequency burst stimulation. In 5 patients atrial fibrillation or phrenic nerve stimulation was induced, and the remaining 15 patients served as the experimental group. Twenty additional patients underwent off-pump surgical revascularization without IVC-IAGP stimulation and served as the control group. On arrival in the intensive care unit, the experimental group underwent IVC-IAGP stimulation for 6 hours. Blood samples were collected at different times. RESULTS: The serum levels of cytokines were not statistically different at baseline and on arrival in the intensive care unit between the groups, while they proved statistically different after 6 hours of stimulation: interleukin-6 (EG: 121 ± 71 pg/mL vs CG: 280 ± 194 pg/mL; P = .004), tumor necrosis factor-α (EG: 2.68 ± 1.81 pg/mL vs CG: 5.87 ± 3.48 pg/mL; P = .003), vascular endothelial growth factor (EG: 93 ± 43 pg/mL vs CG: 177 ± 86 pg/mL; P = .002), and epidermal growth factor (EG: 79 ± 48 pg/mL vs CG: 138 ± 76 pg/mL; P = .012). CONCLUSIONS: Prolonged burst IVC-IAGP stimulation after surgical revascularization appears to be feasible and safe and significantly reduces inflammatory cytokines in the postoperative period.

Cardioprotection with volatile anesthetics: mechanisms and clinical implications.

Cardiac surgery and some noncardiac procedures are associated with a significant risk of perioperative cardiac morbid events. Experimental data indicate that clinical concentrations of volatile general anesthetics protect the myocardium from ischemia and reperfusion injury, as shown by decreased infarct size and a more rapid recovery of contractile function on reperfusion. These anesthetics may also mediate protective effects in other organs, such as the brain and kidney. Recently, a number of reports have indicated that these experimentally observed protective effects may also have clinical implications in cardiac surgery. However, the impact of the use of volatile anesthetics on outcome measures, such as postoperative mortality and recovery in cardiac and noncardiac surgery, is yet to be determined.

Effect of lung volume reduction surgery for severe emphysema on right ventricular function.

Lung volume reduction surgery (LVRS) can improve the functional capacity of selected patients with severe emphysema. Hypothesized physiologic effects of LVRS include an improvement in right ventricular function, although this has not been investigated in detail. To help clarify this issue, we used fast-thermistor thermodilution at rest and during submaximal upright exercise in 12 patients, before and 6 mo after bilateral LVRS. Preoperatively, all patients had severe airflow obstruction, with a mean FEV(1) of 0.69 L and an RV-to-TLC ratio of 0.67. Six months after LVRS, significant improvements occurred in respiratory function measures (+0.39 L in FEV(1), p < 0.002; and +/- 0.15 in RV/TLC ratio, p < 0.002) and in right ventricular function indexes measured at rest (+0.21 L in cardiac index [CI], p < 0.01; and +3.0 ml in stroke volume, p < 0.01) and during exercise (+0.9 L in CI, p < 0.002; +10.0 ml in stroke volume index, p < 0.002; and +20% in ejection fraction [EF], p < 0.002). A significant correlation was found between pre- to postoperative changes in the EF response to exercise and changes in the RV/TLC ratio (R = -0.68; p = 0.01). We conclude that a significant improvement in right ventricular performance, particularly during exercise, can occur 6 mo after bilateral LVRS.