GCSF with or without chemotherapy compared to Plerixafor with GCSF as salvage mobilization regimen in patients with multiple myeloma and lymphoma: collection effectiveness and cost effectiveness analysis.

INTRODUCTION: Plerixafor is a novel mobilizing agent of peripheral blood stem cells (PBSCs) in lymphoma and multiple myeloma (MM) patients whose cells mobilize poorly. Due to the substantial cost associated with its use, we aimed to compare the effectiveness and cost effectiveness of Plerixafor + GCSF (PG) versus GCSF ± Chemotherapy (GC) as salvage mobilization regimens. METHODS: The charts of consecutive lymphoma and MM patients who had undergone at least one previous attempt of PBSCs mobilization that failed or resulted in an insufficient cell dose for transplant between 2007 and 2010 were retrospectively reviewed. Patients identified received salvage mobilization with GC (prior to 2009) or PG after Plerixafor's FDA approval. Data collected included demographics, medical histories, apheresis yields and transplant outcome. The cost effectiveness analysis was from the perspective of the Jordanian Ministry of Health. The incremental cost effectiveness ratio (ICER) was calculated by dividing the difference in cost by the difference in effectiveness for the two regimens. RESULTS: Five patients received GC and twelve received PG. A minimum CD34+ cell dose of 2 × 10(6) cells/kg was collected from 8 patients (67%) in the PG group compared to 3 (60%) in the GC group (p=0.79). The average costs were US$8570 and US$25,700 for the GC group and the PG group, respectively. The ICER was US$244,714 per successful stem cell collection. CONCLUSION: Salvage Plerixafor use showed a non-significant improvement in PBSCs collection with a significant increase in cost. Prospective comparative effectiveness studies are warranted to inform the optimal salvage mobilization regimen. To our knowledge, this is the first study from the Middle East to describe the effectiveness and cost effectiveness of Plerixafor.

Robotic mitral valve surgery.

Totally endoscopic robotic mitral valve repair is the least invasive surgical therapy for mitral valve disease. Robotic mitral valve surgery demonstrates faster recovery with shorter hospital stays, less morbidity, and equivalent mortality and mid-term durability compared to sternotomy. In this review, we will explore the advantages and disadvantages of robotic mitral valve surgery and consider important technical details of both operative set-up and mitral valve repair techniques. The number of robotic cardiac surgical procedures being performed globally is expected to continue to rise as experience grows with robotic techniques and increasing numbers of cardiac surgeons become proficient with this innovative technology. This will be facilitated by the introduction of newer robotic systems and increasing patient demand.

Heparin therapy during extracorporeal circulation: deriving an optimal activated clotting time during cardiopulmonary bypass for isolated coronary artery bypass grafting.

Bull's seminal work on heparin therapy during cardiopulmonary bypass (CPB) was carried out over 30 years ago and has not been updated in the modern era. No correlation with postoperative blood loss was performed. The optimal activated clotting time (ACT) with regard to blood loss has not been established for patients undergoing CPB. A minimum ACT of 400 is based on the lack of visible formation of clots in the CPB circuit. The effect of heparin dose, sensitivity, metabolism, patient size, elective/urgent, protamine reversal regime, returned pump blood volume and heparin content, and average ACT during CPB with regard to postoperative blood loss and resternotomy was examined in a consecutive series of patients undergoing isolated coronary artery bypass surgery. One hundred forty-four patients undergoing isolated CABG were studied. Resternotomy was too infrequent an event to analyze. Univariate analysis revealed that an average ACT less than 500 or greater than 700 was associated with significantly increased postoperative blood loss (p = .001). Multivariate analyses revealed that body mass index (p < .0001) and total loading dose of heparin (p = .0031) were also significant factors affecting postoperative blood loss. We extended his work by analyzing postoperative blood loss. An average ACT between 500 and 700 in our series was associated with significantly lower blood loss than an ACT higher or lower. We hypothesize that an ACT below 500 is probably associated with a low-grade coagulopathy but not macroscopic clot formation in the CPB circuit, and above 700 heparin rebound may become important. Each unit should evaluate blood loss and determine the optimal ACT target for their program.

Theoretical treatise: arterial pressure during aortic surgery.

The optimum arterial perfusion pressure during cardiopulmonary bypass (CPB) remains uncertain. A correlation in some form with the patients' resting pressure almost certainly exists. Temperature and hematocrit affect blood viscosity. The optimum perfusion pressure during aortic surgery will vary after the initiation of CPB resulting cooling, heating, and hematocrit changes. Poiseuille's Law was used in conjunction with the previously published effects of temperature and hematocrit on blood viscosity to determine the perfusion pressure that would result in the same organ blood flow. Two different scenarios were modeled, constant flow and flow as predicted by Q10 to reflect required oxygen delivery. Temperature, hematocrit, and flow all have a large effect on blood viscosity and, thus, through Poiseuille's Law, blood pressure. As patients are cooled, their blood viscosity goes up through the inherent viscoelastic properties of blood. As temperature drops from 37 degrees to 17 degrees, viscosity doubles. This increased viscosity is offset by a reduction in hematocrit, which is invariably associated with CPB. As the hematocrit drops from 30% to 10%, viscosity of blood halves. These two factors clinically can cancel each other out. The figure demonstrates the effect on blood pressure of a constant flow for various temperature and hematocrits. Reduced need for oxygen delivery, secondary to the principles of Q10, can result in a lower than expected theoretical perfusion pressure. As temperature drops from 37 degrees to 17 degrees, based on Q10, oxygen delivery reduces by 75%. This indicates that flow can be reduced by over 60% if the hematocrit falls from 30% to 20%. This theoretical treatise predicts that blood pressure management should be temperature- and hematocrit-dependent. The target optimal blood pressure will vary during the course of surgery as a result of heating, cooling, and hemodilution. Clinical correlation is needed.

Lissajous figures: an engineering tool for root cause analysis of individual cases--a preliminary concept.

Some patients have short intensive care stay periods and little or no organ dysfunction after cardiac surgery and others do not despite seemingly faultless surgery, perfusion, and anesthesia. These "unknown" reasons for death and morbidity usually relate to organ ischemia and inflammation, but are obviously mutlifactorial. A Lissajous figure is a technique in electrical engineering to compare two different electrical signals. We utilize this basic concept in a very simple manner to potentially identify why some of these unknown deaths or morbidities occur. Utilizing an electronic perfusion database, we retrospectively analyzed 43 patients undergoing aortic surgery with regard to central venous saturations during cooling and rewarming. Isolated aortic valve replacement patients were excluded. Central venous saturation, time, and temperature were plotted to create a Lissajous figure for the whole operation, and during cooling and rewarming separately. Temperature and saturations were analyzed every 20 seconds. Perfusion related variables were registered and uploaded to www.perfsort.net. Lissajous figures during cooling add little to patient care due to their similarity. Isolated rewarming revealed startling differences. It is immediately visually obvious who had short and long periods of tissue ischemia and reperfusion during rewarming in a seemingly uneventful operation. The periods of ischemia can be semi quantified into: none, mild, moderate, and severe. Creation of simple Lissajous figures during rewarming for bypass runs may be an additional helpful tool in root cause analysis of patient death/morbidity when surgery, perfusion, and anesthesia seemed faultless. Low central venous saturations at hypothermic temperatures mean significant metabolic activity, indicating tissue ischemia is occurring. Further work is needed to correlate this concept to outcomes.

Robotic mitral valve surgery: a review and tips for safely negotiating the learning curve.

Totally endoscopic robotic mitral valve repair represents the least invasive surgical therapy for mitral valve disease. Comparative results for robotic mitral valve surgery against sternotomy are impressive, repeatedly demonstrating shorter hospital stay, faster return to normal activities, less morbidity and equivalent mortality and mid-term durability. We lack data comparing robotic approaches to totally endoscopic minimally invasive mitral valve surgery using 3D vision platforms. In this review, we explore the advantages and disadvantages of robotic mitral valve surgery and share technical tips that we have learned to help teams embarking on their robotic journey. We consider factors necessary for the successful implementation of a robotic programme including the importance of training a dedicated team, with the common goal to avoid any compromise in either patient safety or repair quality during the learning curve. As experience grows with robotic techniques and more cardiac surgeons become proficient with this innovative technology, the volume of robotic cardiac procedures around the world will increase helped by the introduction of new robotic systems and patient demand. Well informed patients will increasingly seek out the opportunity of robotic valve reconstruction in reference centres in the hands of a few highly experienced robotic surgeons.

Patient-reported outcome measures after mitral valve repair: a comparison between minimally invasive and sternotomy.

OBJECTIVES: To compare patient-reported outcome measures of minimally invasive (MI) to sternotomy (ST) mitral valve repair. METHODS: We included all patients undergoing isolated mitral valve surgery via either a right mini-thoracotomy (MI) or ST over a 36-month period. Patients were asked to complete a modified Composite Physical Function questionnaire. Intraoperative and postoperative outcomes, and patient-reported outcome measures were compared between 2 propensity-matched groups (n = 47/group), assessing 3 domains: 'Recovery Time', 'Postoperative Pain' (at day 2 and 1, 3, 6 and 12 weeks) and 'Treatment Satisfaction'. Composite scores for each domain were subsequently constructed and multivariable analysis was used to determine whether surgical approach was associated with domain scores. RESULTS: The response rate was 79%. There was no mortality in either group. In the matched groups, operative times were longer in the MI group (P < 0.001), but postoperative outcomes were similar. Composite scores for Recovery Time [ST 51.7 (31.8-62.1) vs MI 61.7 (43.1-73.9), P = 0.03] and Pain [ST 65.7 (40.1-83.1) vs MI 79.1 (65.5-89.5), P = 0.02] significantly favoured the MI group. Scores in the Treatment Satisfaction domain were high for both surgical approaches [ST 100 (82.5-100) vs MI 100 (95.0-100), P = 0.15]. The strongest independent predictor of both faster recovery parameter estimate 12.0 [95% confidence interval (CI) 5.7-18.3, P < 0.001] and less pain parameter estimate 7.6 (95% CI 0.7-14.5, P = 0.03) was MI surgery. CONCLUSIONS: MI surgery was associated with faster recovery and less pain; treatment satisfaction and safety profiles were similar.

Cost Analysis of Minimally Invasive Mitral Valve Surgery in the UK National Health Service.

BACKGROUND: In the UK National Health Service, finite resources make the adoption of minimally invasive (MI) mitral valve surgery challenging unless greater operative costs (vs sternotomy [ST]) are balanced by postoperative savings. This study examined whether the cost analysis now became unfavorable. METHODS: All patients (n = 380) undergoing isolated mitral valve surgery with or without a maze procedure over a 3-year period by either MI or ST approaches were included. Propensity matching (2 cohorts, 1:1 matched;, n = 75 per group) and multivariable regression were used to assess for the effect on cost. Cost data were prospectively collected from Service Line Reporting and reported in Sterling (£) as median (interquartile range [IQR]). RESULTS: Matched data revealed that total hospital costs were equivalent (MI vs ST, £16,672 [IQR, £15,044, £20,611] vs £15,875 [IQR, £12,281, £20,687]; P .33). Three of 15 costing pools were significantly different: operative costs were higher for the MI group (MI vs ST, £7458 [IQR, £6738, £8286] vs £5596 iIQR, £4204, £6992]; P < .001), whereas ward costs (boarding, nursing) (MI vs ST, £1464 [IQR, £1146, £1864] vs £1733 [IQR, £1403, £2445] P = .006) and pharmacy services (MI vs ST, £187 [IQR, £140, £239] vs £244 [IQR, £179, £375] P < .001) were lower for the MI group. Hospital stay was shorter in the MI group (MI vs ST, 6 days [IQR, 5, 8 days] vs 8 days [IQR, 6, 11 days]; P < .001). Multivariable regression produced similar findings. CONCLUSIONS: There was no difference in overall hospital cost between MI and ST mitral valve surgery: higher operative costs of MI surgery were offset by lower postoperative costs, with a 2-day shorter hospital stay.

Biosynthesis of Silver Nanoparticles from Citrobacter freundii as Antibiofilm Agents with their Cytotoxic Effects on Human Cells.

BACKGROUND: Nanomaterials have recently been identified for their potential benefits in the areas of medicine and pharmaceuticals. Among these nanomaterials, silver nanoparticles (Ag-NPs) have been widely utilized in the fields of diagnostics, antimicrobials, and catalysis. OBJECTIVE: To investigate the potential utility of Citrobacter freundii in the synthesis of silver Nanoparticles (Ag-NPs), and to determine the antimicrobial activities of the Ag-NPs produced. METHODS: Aqueous Ag+ ions were reduced when exposed to C. freundii extract and sunlight, leading to the formation of Ag-NPs. Qualitative microanalysis for the synthesized Ag-NPs was done using UVvis spectrometry, Energy Dispersive X-ray analysis (EDX), and scanning and transmission electron microscopy. The hydrodynamic size and stability of the particles were detected using Dynamic Light Scattering (DLS) analysis. The Ag-NPs' anti-planktonic and anti-biofilm activities against Staphylococcus aureus and Pseudomonas aeruginosa, which are two important skin and wound pathogens, were investigated. The cytotoxicity on human dermal fibroblast cell line was also determined. RESULTS: Ag-NPs were spherical with a size range between 15 to 30 nm. Furthermore, Ag-NPs displayed potent bactericidal activities against both S. aureus and P. aeruginosa and showed noticeable anti-biofilm activity against S. aureus biofilms. Ag-NPs induced minor cytotoxic effects on human cells as indicated by a reduction in cell viability, a disruption of plasma membrane integrity, and apoptosis induction. CONCLUSION: Ag-NPs generated in this study might be a future potential alternative to be used as antimicrobial agents in pharmaceutical applications for wound and skin related infections.

Patient directed bypass: cooling for aortic surgery--a preliminary concept.

No consensus exists as to the temperature to cool to on bypass for surgery involving the aortic arch. Excluding normothermic surgery, which is rarely performed for arch work, circulatory arrest, anterograde, and retrograde cerebral perfusion either in isolation or in combination remain the techniques of "cerebral protection." To date, no account of individual patient body or cerebral function variation is involved. Utilizing an electronic perfusion database we retrospectively analyzed 10 patients undergoing aortic arch work with regard to mixed venous saturations during cooling. Perfusion related variables were registered and uploaded to www.perfsort.net. We regarded a saturation of 100% as being indicative of no oxygen extraction, implying no metabolic activity--the theoretical goal prior to a circulatory arrest period. There is enormous variation in the temperature at which metabolic activity of the body stops. We had a range from 17-25 degrees. Patients were cooled for an average of 6 (SD 3.4) degrees below which oxygen extraction had ceased to occur. Potentially we are adding 111 minutes (SD 62) of unnecessary bypass time. This may imply that excessive cooling is occurring in some individuals undergoing arch surgery. Patient directed cooling for aortic arch surgery may help to reduce the morbidity/physical insult associated with severe hypothermia. This work is very preliminary but may help us to depart from the one size fits all paradigm that exists in current clinical practice. Correlation with bispectral index, electroencephalogram monitoring and neurological outcomes is needed.

The effect of thoracic epidural bupivacaine and an intravenous adrenaline infusion on gastric tube blood flow during esophagectomy.

BACKGROUND: Gastric tube necrosis is a major cause of anastomotic leak after esophagectomy. A correlation has been shown between reduced flux at the anastomotic end of the gastric tube and anastomotic leaks. METHODS: We prospectively studied the effect of intraoperative thoracic epidural bupivacaine and subsequent adrenaline infusion on hemodynamics and flux in the gastric tube. RESULTS: Administering the epidural bolus significantly decreased flux at the anastomotic end of the gastric tube (P < 0.01). Gastric flux was returned to baseline by an adrenaline infusion. CONCLUSIONS: The administration of a thoracic epidural bolus may decrease flux at the anastomotic end of the gastric tube.

Critical care admissions in a cardiothoracic hospital: Mortality in patients aged over 80 years.

BACKGROUND: Cardiac surgery is increasingly performed on patients aged 80 years and over. Previous studies have shown an associated longer length of hospital stay and higher morbidity and mortality. Our aim was to establish whether an increased mortality was demonstrated in patients aged over 80 undergoing surgery in our centre, and the impact of age upon critical care and hospital stay, and 30-day and 6-month survival. METHODS: Over a 12-month period, 2042 critical care episodes were examined collectively and divided into those undergoing thoracic and cardiac surgery. Propensity matching of 216 patients who underwent cardiac surgery was performed for parameters including Acute Physiology And Chronic Health Evaluation (APACHE) II and Intensive Care National Audit and Research Centre score. RESULTS: Of the admissions studied, 1784 were of patients under 80 years of age, and 258 over 80. Thirty-day mortality of those aged over 80 was significantly higher (8.9% vs. 3.8%, p < 0.0001), although the number of days of each level of organ support and total duration of critical care stay was not significantly different. Propensity matching of cardiac surgery patients indicated a longer length of hospital stay in those aged over 80, but no significant difference in length of critical care stay or mortality at six months. CONCLUSIONS: As previously demonstrated, we found an increased mortality in the older patient group. Following propensity matching, there was no significant difference in 30-day or 6-month mortality. Older patients must be fitter than their younger peers to compensate for the effects of age on APACHE II score. Even when this is taken into consideration, cardiothoracic operations appear to be safe in patients aged over 80.

Cytomegalovirus Reactivation in Adult Recipients of Autologous Stem Cell Transplantation: a Single Center Experience.

INTRODUCTION: Cytomegalovirus (CMV) reactivation and infection are well-recognized complications after allogeneic stem cell transplantation (SCT). Only a few studies have addressed CMV reactivation after autologous SCT (ASCT). METHODS: We retrospectively reviewed medical records of 210 adult patients who underwent ASCT for lymphoma or multiple myeloma (MM) at a single center from January 1(st), 2007 until December 31(st), 2012. All patients were monitored weekly with CMV antigenemia test till day 42 after transplantation, and for 2 months after last positive test in those who had any positive CMV antigenemia test before day 42. RESULTS: Thirty-seven (17.6%) patients had CMV reactivation; 23 patients had lymphoma while 14 had MM as the underlying disease. There was no difference in the rate of CMV reactivation between lymphoma and MM patients (20% versus 14.7%, P = 0.32). The majority of the patients were treated with ganciclovir/valganciclovir, all patients had their reactivation resolved with therapy, and none developed symptomatic CMV infection. None of the patients who died within 100 days of transplantation had CMV reactivation. Log-rank test showed that CMV reactivation had no effect on the overall survival of patients (P values, 0.29). CONCLUSION: In our cohort, CMV reactivation rate after ASCT was 17.6%. There was no difference in reactivation rates between lymphoma and MM patients. With the use of preemptive therapy, symptomatic CMV infection was not documented in any patient in our cohort. CMV reactivation had no impact on patients' survival post ASCT.

Long-term survival of patients with pulmonary disease undergoing coronary artery bypass surgery.

OBJECTIVES: We sought to investigate the long-term survival of patients with obstructive, restrictive and chronic obstructive pulmonary disease (COPD) as defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD). METHODS: A prospective database was retrospectively analysed and cross-correlated with the UK strategic tracking service to evaluate survival after primary coronary artery bypass grafts (CABG). Univariate and multivariate Cox regression analyses were performed. Three separate multivariate analyses were performed: COPD GOLD criteria for obstructive and/or restrictive lung disease, forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and the FEV1/FVC ratio to investigate the effect of FEV1 and FVC individually. RESULTS: We analysed 13 337 primary CABG procedures. The median follow-up was 7 years. Univariate analysis demonstrated that obstructive (P < 0.0001), restrictive (P < 0.0001) and mixed obstructive and restrictive pulmonary disease (P < 0.0001), and COPD as defined by the GOLD criteria (P < 0.0001), are all significant factors determining long-term survival. Cox regression analysis identified age, diabetes, moderate LV, poor LV, peripheral vascular disease, dialysis, left internal mammary artery (LIMA) usage, EuroSCORE, cardiopulmonary bypass and creatinine kinase muscle-brain isoenzyme as significant factors in addition to pulmonary disease that determine long-term survival. Moderate and severe COPD defined by GOLD criteria were significant factors determining long-term survival, but mild COPD had no significant effect. Obstructive and restrictive lung disease were both significant factors determining long-term survival. Restrictive lung disease, however, carried a greater prognostic significance (higher hazard ratio 2.2 vs 1.6) than obstructive. LIMA utilization in patients with COPD was not associated with an increased intensive care unit stay, re-intubation rate or in-hospital mortality rate. CONCLUSIONS: Pulmonary disease is a significant factor determining long-term survival. Patients with severe COPD still have a relatively good long-term survival and should not be denied surgery. LIMA utilization in patients with COPD results in a significantly increased long-term survival, without an increased intensive care unit stay, re-intubation rate or in-hospital mortality rate.

Phenylephrine infusion improves blood flow to the stomach during oesophagectomy in the presence of a thoracic epidural analgesia.

OBJECTIVES: Gastric tube necrosis is a major cause of mortality after oesophagectomy. The construction of the gastric tube used for oesophageal reconstruction involves a division of several arteries leading to a reduction in the blood supply at the fundus, which is used for the oesophageal anastomosis. This study was undertaken to determine the effect of thoracic epidural anaesthesia and intravenous phenylephrine on haemodynamics and blood flow in the tubularized stomach. METHODS: Ten patients undergoing an oesophagectomy were prospectively studied. Pulmonary artery catheters were used to measure haemodynamic changes, and laser Doppler flow probes were used to measure gastric blood flow. The effects of an intraoperative thoracic epidural and subsequent intravenous phenylephrine infusion were documented. RESULTS: The administration of a thoracic epidural bolus of bupivacaine 0.25% at 0.1 ml kg resulted in a significant reduction in flux at the anastomotic end of the newly formed gastric tube from a median of 57-41 perfusion units (P = 0.003). A subsequent intravenous phenylephrine infusion titrated to restore mean arterial pressure significantly increased the flux at the anastomotic end from a median of 41-66 perfusion units (P = 0.009). CONCLUSIONS: An intravenous phenylephrine infusion can reverse the epidural bolus-induced reduction in blood flow at the anastomotic end of the newly formed gastric tube.

Impact of chronic obstructive pulmonary disease severity on surgical outcomes in patients undergoing non-emergent coronary artery bypass grafting.

OBJECTIVES: Although the association between chronic obstructive pulmonary disease (COPD) and adverse surgical outcomes has been previously demonstrated, the impact of COPD severity on postoperative mortality and morbidity remains unclear. Our objective was to analyse the prognostic implication of COPD stages as defined by the Global Initiative for Chronic Obstructive Lung Disease. METHODS: Between September 1997 and April 2010, 13,638 patients undergoing first time isolated CABG were retrospectively reviewed, of whom 2421 patients were excluded due to lack of spirometry records or restrictive pattern on spirometry. The remaining 11,217 patients were divided into three groups: group 1 (including patients with normal spirometry and patients with mild COPD (FEV1/FVC ratio<70%, FEV1≥80% predicted), group 2 (moderate COPD: FEV1/FVC ratio<70%, 50%≤FEV1<80% predicted) and group 3 (severe COPD: FEV1/FVC ratio<70%, FEV1<50% predicted). Logistic regression was used to examine the effect of COPD severity on early mortality and morbidity, after adjusting for differences in patient characteristics. RESULTS: Early mortality in the three groups was 1.4, 2.9 and 5.7% respectively (P<0.001). Similarly, a consistent trend of increasing frequency of postoperative complications with advanced COPD stage was noted. On multivariate analysis, severe COPD was found to be significantly associated with early mortality [adjusted OR, 2.31 (95% CI) (1.23-4.36)], P=0.01. CONCLUSIONS: The severity of COPD as defined by spirometry can be a prognostic marker in patients undergoing CABG. Spirometric criteria may help refining currently used operative risk scores.

Outcomes and predictors of prolonged ventilation in patients undergoing elective coronary surgery.

OBJECTIVES Despite the seriousness of prolonged mechanical ventilation (PMV) as a postoperative complication, previously proposed risk prediction models were met with limited success. The purpose of this study was to identify perioperative variables associated with PMV in elective primary coronary bypass surgery. PMV was defined as the need for intubation and mechanical ventilation for >72 h, after completion of the operation. METHODS Between April 1997 and September 2010, 10 ,977 consecutive patients were retrospectively reviewed. A series of two multivariate logistic regression analyses were carried out to identify preoperative predictors of prolonged ventilation and the impact of operative variables. RESULTS PMV occurred in 215 (1.96%) patients; 119 (55.3%) of these underwent tracheostomy. At multivariate analysis, predictors included NYHA higher than class II (odds ratio [OR], 1.77; 95% confidence intervals [CI], 1.34-2.34), renal dialysis (OR, 5.5; 95% CI, 2.08-14.65), age at operation (OR, 1.04; 95% CI, 1.02-1.06), reduced FEV(1) (OR, 0.99; 95% CI, 0.98-0.99), body mass index >35 kg/m(2) (OR, 1.73; 95% CI, 1.14-2.63). On serial logistic regression analyses, operative variables added little to the discriminatory power of the model. Kaplan-Meier survival curves showed reduced survival among PMV patients (P < 0.001) with an improved survival in the tracheostomy subgroup. CONCLUSIONS PMV after coronary bypass is associated with a reduction in early and mid-term survival. Risk modelling for PMV remains problematic even when examining a more homogenous lower risk group.