Determinants of hospital charges for coronary artery bypass surgery: the economic consequences of postoperative complications

Impact of diabetic versus non-diabetic patients undergoing coronary artery bypass graft surgery on postoperative wound complications: A meta-analysis

The effect of diabetes mellitus (DM) on the incidence of postoperative wound complications in patients with coronary artery bypass grafting (CABG) is still unclear. Thus, we performed a meta-analysis of CABG in DM patients to evaluate existing data from both prospective and historical cohorts. The objective of this trial was to assess the relevance and extent of the effect of diabetes on the outcome of previous CABG procedures. Data sources like Embase and Pubmed were found throughout the research, and the language was limited to English through manual search. The searches were performed up to August 2023. The data were extracted from the study of the inclusion/exclusion criteria, the features of the population, the statistical approach and the clinical results. A qualitative evaluation of the qualifying studies has been carried out. Out of the 1874 studies identified, 21 cohort studies were chosen for analysis. Meta-analyses were performed in 258 454 patients (71 351 diabetic and 187 103 non-diabetic). Twenty-one studies on deep sternal wound infections in CABG patients showed a lower rate of deep sternal wound infections in non-diabetes group compared with those with diabetes (OR, 2.13; 95% CI: 1.97, 2.31, p < 0.00001). And 16 studies of superficial wound infections in patients undergoing CABG were found to be associated with a lower rate of superficial injury (OR, 1.93; 95% CI: 1.53, 2.43, p < 0.00001) compared with those with diabetes; In five trials, perfusion time during CABG (MD, 2.31; 95% CI: -0.16, 4.79, p = 0.07) was observed, and there were no significant differences between diabetes and non-diabetes. Currently, there is a higher risk for CABG in diabetes than in non-diabetes patients with sternal infections and superficial injuries. Future randomized trials will concentrate on the treatment of such perioperatively related complications, which will lower the risk of postoperative wound infection in diabetes.

Effect of Perioperative Oral Vitamin C Supplementation on In-Hospital Postoperative Medication Costs for Cardiac Surgery Patients: A Prospective, Single-Centre, Randomised Clinical Trial

BACKGROUND

Due to its antioxidant properties, vitamin C might be a promising and effective strategy for preventing postoperative atrial fibrillation (POAF) after cardiac surgery. This study was aimed at evaluating whether vitamin C supplementation is effective in reducing the cost of in-hospital postoperative medication used for patients undergoing coronary artery bypass (CABG) or valve surgery (±CABG).

OBJECTIVE

The primary goal of this study was to evaluate the impact of perioperative vitamin C supplementation in patients undergoing cardiac surgery on in-hospital postoperative medication costs, while secondary endpoints were the effects on length of stay (LOS) in both the intensive care unit (ICU) and the hospital, and the incidence of POAF.

MATERIAL AND METHODS

From November 2018 to January 2021, 253 patients planned for CABG or valve surgery (±CABG) in AZ Maria Middelares, Ghent, Belgium, and who met the inclusion criteria (≥18 years of age, all having cardiac sinus rhythm, and who provided written informed consent) were randomised into a placebo group or vitamin C group. The medication was administered orally (1 g twice daily), starting from 5 days preoperatively until 10 days postoperatively. The medication used, LOS in the hospital/ICU, and development of clinically relevant POAF in the ICU were registered.

RESULTS

Mean medication costs were €264.6 ± 98.1 for patients in the vitamin C group and €294.9 ± 267.3 for patients in the placebo group. When stratifying according to the type of surgery (CABG or valve surgery [±CABG]), these costs did not significantly differ. There was no significant difference in LOS or the incidence of clinically relevant POAF.

CONCLUSION

Our data did not identify any short-term financial impact on postoperative medication costs after oral perioperative vitamin C supplementation (1 g twice daily) for patients undergoing a CABG procedure or valve surgery (±CABG). No effect was found on the LOS or the incidence of clinically relevant POAF. Potential effects in the longer term, after intravenous administration of vitamin C or in other types of (cardiac) surgery, are still to be investigated.

CLINICAL TRIALS REGISTRATION NUMBER

NCT03592680.

Effect of Positive Expiratory Pressure Therapy on Lung Volumes and Health Outcomes in Adults With Chest Trauma: A Systematic Review and Meta-Analysis

OBJECTIVE

The purposes of this study were to evaluate the effect of positive expiratory pressure (PEP) therapy on lung volumes and health outcomes in adults with chest trauma and to investigate any adverse effects and optimal dosages leading to the greatest positive impact on lung volumes and recovery.

METHODS

Data sources were MEDLINE/PubMed, Embase, Cochrane Library, Physiotherapy Evidence Database, CINAHL, Open Access Thesis/Dissertations, EBSCO Open Dissertations, and OpenSIGLE/Open Grey. Randomized controlled trials investigating PEP therapy compared with usual care or other physical therapist interventions were included. Participants were >18 years old and who were admitted to the hospital with any form of chest trauma, including lung or cardiac surgery, blunt chest trauma, and rib fractures. Methodological quality was assessed using the Physiotherapy Evidence Database Scale, and the level of evidence was downgraded using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

Eleven studies involving 661 participants met inclusion eligibility. There was very low-level evidence that PEP improved forced vital capacity (standardized mean difference = -0.50; 95% CI = -0.79 to -0.21), forced expiratory volume in 1 second (standardized mean difference = -0.38; 95% CI = -0.62 to -0.13), and reduced the incidence of pneumonia (relative risk = 0.16; 95% CI = 0.03 to 0.85). Respiratory muscle strength also significantly improved in all 3 studies reporting this outcome. There was very low-level evidence that PEP did not improve other lung function measures, arterial blood gases, atelectasis, or hospital length of stay. Both PEP devices and dosages varied among the studies, and no adverse events were reported.

CONCLUSION

PEP therapy is a safe intervention with very low-level evidence showing improvements in forced vital capacity, forced expiratory volume in 1 second, respiratory muscle strength, and incidence of pneumonia. It does not improve arterial blood gases, atelectasis, or hospital length of stay. Because the evidence is very low level, more rigorous physiological and dose-response studies are required to understand the true impact of PEP on the lungs after chest trauma.

IMPACT

There is currently no strong evidence for physical therapists to routinely use PEP devices following chest trauma. However, there is no evidence of adverse events; therefore, in specific clinical situations, PEP therapy may be considered.

The need for cardiac surgery differential tariffs in Israel at the era of aging population and emerging technology: Importance of procedure type and patient complexity as assessed by EuroSCORE

Background

Reimbursement for cardiac surgical procedures in Israel is uniform and does not account for diversity in costs of various procedures or for diversity in patient mix. In an era of new and costly technology coupled with higher risk patients needing more complex surgery, these tariffs may not adequately reflect the true financial burden on the caregivers. In the present study we attempt to determine whether case mix and complexity of procedures significantly affect cost to justify differential tariffs.

Methods

We included all patients undergoing cardiac surgery at Shaare Zedek Medical Center between the years 1993–2016. Patients were stratified according to (1) type of surgery and (2) clinical profile as reflected by the predicted operative risk according to the European System for Cardiac Operative Risk Evaluation (EuroSCORE). Approximate cost of each group of patients was estimated by the average number of days in the Intensive Care Unit and days in the postoperative ward multiplied by the respective daily costs as determined by the Ministry of Health. We then added the fixed cost of the components used in the operating room (manpower and disposables). The final estimated cost (the outcome variable) was then evaluated as it relates to type of surgery and clinical profile. ANOVA was used to analyze cost variability between groups, and backward regression analysis to determine the respective effect of the abovementioned variables on cost. Because of non-normal distribution, both costs and lengths of stay were Log-transformed.

Results

Altogether there were 5496 patients: 3863, 836, 685 and 112 in the isolated CABG, CABG + valve, 1 valve and 2 valves replacement groups. By ANOVA, the costs in all EuroSCORE subgroups were significantly different from each other, increasing with increased EuroSCORE subgroup. Cost was also significantly different among procedure groups, increasing from simple CABG to single valve surgery to CABG + valve surgery to 2-valve surgery. In backward stepwise multiple regression analysis, both type of procedure and EuroSCORE group significantly impacted cost. ICU stay and Ward stay were significantly but weakly related while EuroSCORE subgroup was highly predictive of both ICU stay and ward stay.

Conclusions

The cost of performing heart surgery today is directly influenced by both patient profile as well as type of surgery, both of which can be quantified. Modern day technology is costly yet has become mandatory. Thus reimbursement for heart surgery should be based on differential criteria, namely clinical risk profile as well as type of surgery. Our results suggest an urgent need for design and implementation of a differential tariff model in the Israeli reimbursement system. We suggest that a model using a fixed, average price according to the type of procedure costs, in addition to a variable hospitalization cost (ICU + ward) determined by the patient EuroSCORE or EuroSCORE subgroup should enable an equitable reimbursement to hospitals, based on their case mix.

Effects of non-invasive ventilation in subjects undergoing cardiac surgery on length of hospital stay and cardiac-pulmonary complications: a systematic review and meta-analysis

Background

Cardiac surgery often leads to pulmonary complications. Non-invasive ventilation (NIV) is a mechanical ventilation modality that may help to prevent the pulmonary complications, and the role of the prophylactic use of NIV in patients after cardiac surgery remains controversial.

Methods

We searched PubMed, Embase, Web of Science and Cochrane Central for randomized controlled trials comparing the use of NIV (continues positive airway pressure or bi-level positive airway pressure) with standard treatment in post-cardiac surgery subjects without language restriction. Two investigators screened the eligible studies up to July, 2019. Meta-analysis using random effect model or fixed effect model was conducted for pulmonary complications, mortality, rate of reintubation and cardiac complications, and mean difference (MD) or standard mean difference for length of hospital stay and length of ICU stay.

Results

We included nine randomized controlled trails with 830 subjects. The use of NIV failed to reduce the risk of pulmonary complications, including atelectasis [risk rate (RR) 0.60; 95% confidence interval (CI): 0.28 to 1.28, P=0.19] and pneumonia (RR 0.27; 95% CI: 0.05 to 1.64, P=0.16). However, it has shortened the length of ICU stay (MD -1.00 h, 95% CI: -1.38 to -0.63, P<0.00001) and the length of hospital stay (MD -1.00 d, 95% CI: -1.12 to -0.87, P<0.00001). NIV also failed to reduce the rate of reintubation (RR 0.68; 95% CI: 0.21 to 2.26, P=0.53) or the risk of cardiac complications (RR 0.81; 95% CI: 0.59 to 1.13, P=0.22).

Conclusions

The prophylactic use of NIV immediately in post-cardiac subjects who underwent cardiac surgery might be able to shorten the length of hospital stay and the length of ICU stay, but it has no significant effect on pulmonary complications, rate of reintubation or cardiac complications.

Effect of hospital volume on outcomes of total hip arthroplasty: a systematic review and meta-analysis

BACKGROUND

A shift in the healthcare system towards the centralization of common yet costly surgeries, such as total hip arthroplasty (THA), to high-volume centers of excellence, is an attempt to control the economic burden while simultaneously enhancing patient outcomes. The "volume-outcome" relationship suggests that hospitals performing more treatment of a given type exhibit better outcomes than hospitals performing fewer. This theory has surfaced as an important factor in determining patient outcomes following THA. We performed a systematic review with meta-analyses to review the available evidence on the impact of hospital volume on outcomes of THA.

MATERIALS AND METHODS

We conducted a review of PubMed (MEDLINE), OVID MEDLINE, Google Scholar, and Cochrane library of studies reporting the impact of hospital volume on THA. The studies were evaluated as per the inclusion and exclusion criteria. A total of 44 studies were included in the review. We accessed pooled data using random-effect meta-analysis.

RESULTS

Results of the meta-analyses show that low-volume hospitals were associated with a higher rate of surgical site infections (1.25 [1.01, 1.55]), longer length of stay (RR, 0.83[0.48-1.18]), increased cost of surgery (3.44, [2.57, 4.30]), 90-day complications (RR, 1.80[1.50-2.17]) and 30-day (RR, 2.33[1.27-4.28]), 90-day (RR, 1.26[1.05-1.51]), and 1-year mortality rates (RR, 2.26[1.32-3.88]) when compared to high-volume hospitals following THA. Except for two prospective studies, all were retrospective observational studies.

CONCLUSIONS

These findings demonstrate superior outcomes following THA in high-volume hospitals. Together with the reduced cost of the surgical procedure, fewer complications may contribute to saving considerable opportunity costs annually. However, a need to define objective volume-thresholds with stronger evidence would be required.

TRIAL REGISTRATION

PROSPERO CRD42019123776.

Deep sternal wound infection - latissimus dorsi flap is a reliable option for reconstruction of the thoracic wall

Background

At present, data describing patients’ long-term outcomes, quality of life, and survival after deep sternal wound infection are rarely available.

The purpose of our study was to evaluate functional outcome and patient well-being after debridement and reconstruction of the sternal defect using a pedicled latissimus dorsi flap following deep sternal wound infection (DSWI).

Methods

This retrospective analysis reviewed 106 cases of DSWI after open-heart surgery treated between May 1, 2012, and May 31, 2015. The parameters of interest were demographic and medical data, including comorbidity and mortality. Follow-up consisted of physical examination of the patients using a specific shoulder assessment, including strength tests and measurements of pulmonary function.

Results

The population consisted of 69 (65%) male and 37 (35%) female patients. Their average age at the time of plastic surgery was 69 years (range: 35–85). The 30-day mortality was 20% (n = 21); after one-year, mortality was 47% (n = 50), and at follow-up, it was 54% (n = 58).

Heart surgery was elective in 45 cases (42%), urgent in 31 cases (29%) and for emergency reasons in 30 cases (28%). The preoperative European System for Cardiac Operative Risk Evaluation (EuroSCORE) averaged 16.3 (range: 0.88–76.76).

On the dynamometer assessment, a value of 181 Newton (N) (±97) could be achieved on the donor side, in contrast to 205 N (±91) on the contralateral side.

The inspiratory vital capacity of the lung was reduced to an average of 70.58% (range: 26–118), and the forced expiratory volume in 1 s was decreased to an average of 69.85% (range: 38.2–118).

Conclusions

Given that only small adverse effects in shoulder function, strength, and pulmonary function were observed, the latissimus dorsi flap appears to be a safe and reliable option for the reconstruction of the sternal region after DSWI.

Nasal High Flow Versus Conventional Oxygen Therapy for Postoperative Cardiothoracic Surgery Patients

BACKGROUND

Reintubation and complications in postoperative cardiothoracic patients remain high despite medical advancements. A 2-year retrospective, observational study was conducted in postextubated cardiothoracic patients to assess the effectiveness of the current standard-conventional oxygen therapy (COT) compared with a nasal high flow (NHF) therapy.

OBJECTIVES

The objective of this study was to understand whether NHF therapy would reduce the need for reintubation and improve clinical outcomes after surgery.

METHOD

All consecutive postoperative patients who had same-day elective cardiothoracic surgery in a tertiary hospital were included. The 2013 data were from patients' charts who received COT, and the 2014 data were from patients' charts after the implementation of NHF therapy post extubation as a standard of care.

RESULTS

A total of 400 patient charts were analyzed: 221 and 179 patients in the COT and NHF, respectively. No significant difference was seen in the frequency of reintubation (P = .48). Despite both cohorts having the same length of stay (P = .10), patients treated with NHF required less time on supplemental oxygen (P = .001). Day 1 postoperative chest x-ray results did not show any significant differences between groups, whereas day 2 x-rays showed worsening results in the COT cohort (P < .001). Furthermore, the incidence of ventilator-associated pneumonia (VAP) post extubation was significantly higher in the COT cohort, with zero VAP episodes reported in the NHF cohort (P = .02).

DISCUSSION

Although this study was not able to demonstrate the reduction in reintubation between groups, the use of NHF compared with COT seems to reduce the time spent on oxygen therapy and decrease the rate of VAP. Further evidence including randomized controlled trials is required to determine the impact of NHF on reintubation and complications in postoperative cardiothoracic surgery.

Postoperative Atrial Fibrillation: Evaluation of its Economic Impact on the Costs of Cardiac Surgery

Objective

The objective of this study was to calculate the direct costs of postoperative atrial fibrillation (POAF) in a high-complexity cardiovascular hospital.

Methods

We performed a cost analysis with a pairwise-matched design. Twenty-two patients with POAF and 22 patients without this complication were included. Pair-matching was performed (1:1) based on the following criteria: identical type of surgery, similar EuroSCORE II values, and absence of any other postoperative complication.

Results

The total hospital cost was significantly higher in the POAF group than in the non-POAF group (US$ 10,880 [± 2,688] vs. US$ 8,856 [± 1,782], respectively, for each patient; P=0.005). This difference was attributable to postoperative costs (US$ 3,103 [± 1,552] vs. US$ 1,238 [± 429]; P=0.0001) for patients with or without POAF, respectively. The median postoperative lengths of stay were 9 (range 5-17) and 5 (3-9) days for patients with and without POAF (P=0.032), respectively. Preoperatively, no differences were found in the EuroSCORE II values (median 1.7 vs. 1.6, respectively; P=0.91) or direct costs (US$ 1,127 vs. US$ 1,063, respectively; P=0.56) between POAF and non-POAF groups.

Conclusion

POAF generates a high economic burden in the overall costs of cardiac surgery, and our results reveal the differential contribution of each of the evaluated factors. This information, which was previously unavailable in this setting, is essential for the development of more effective prevention strategies.

Anticoagulation, bleeding and blood transfusion practices in Australasian cardiac surgical practice

We surveyed contemporary Australasian cardiac surgical and anaesthetic practice, focusing on antiplatelet and antifibrinolytic therapies and blood transfusion practices. The cohort included 499 sequential adult cardiac surgical patients in 12 Australasian teaching hospitals. A total of 282 (57%) patients received red cell or component transfusion. The median (IQR) red cell transfusion threshold haemogloblin levels were 66 (61-73) g/l intraoperative^ and 79 (74-85) g/l postoperatively. Many (40%) patients had aspirin within five days of surgery but this was not associated with blood loss or transfusion; 15% had Clopidogrel within seven days of surgery. In all, 30 patients (6%) required surgical re-exploration for bleeding. Factors associated with transfusion and excessive bleeding include pre-existing renal impairment, preoperative Clopidogrel therapy, and complex or emergency surgery. Despite frequent (67%) use of antifibrinolytic therapy, there was a marked variability in red cell transfusion rates between centres (range 17 to 79%, P <0.001). This suggests opportunities for improvement in implementation of guidelines and effective blood-sparing interventions. Many patients presenting for surgery receive antiplatelet and/or antifibrinolytic therapy, yet the subsequent benefits and risks remain unclear.

Intermediate Care Unit After Cardiac Surgery: Impact on Length of Stay and Outcomes

INTRODUCTION AND OBJECTIVES

Current postoperative management of adult cardiac surgery often comprises transfer from the intensive care unit (ICU) to a conventional ward. Intermediate care units (IMCU) permit hospital resource optimization. We analyzed the impact of an IMCU on length of stay (both ICU and in-hospital) and outcomes (in-hospital mortality and 30-day readmissions) after adult cardiac surgery (IMCU-CS).

METHODS

From November 2012 to April 2015, 1324 consecutive patients were admitted to a university hospital for cardiac surgery. In May 2014, an IMCU-CS was established for postoperative care. For the purposes of this study, patients were classified into 2 groups, depending on the admission period: pre-IMCU-CS (November 2012-April 2014, n=674) and post-IMCU-CS (May 2014-April 2015, n=650).

RESULTS

There were no statistically significant differences in age, sex, risk factors, comorbidities, EuroSCORE 2, left ventricular ejection fraction, or the types of surgery (valvular in 53%, coronary in 26%, valvular plus coronary in 11.5%, and aorta in 1.8%). The ICU length of stay decreased from 4.9±11 to 2.9±6 days (mean±standard deviation; P<.001); 2 [1-4] to 1 [0-3] (median [Q1-Q3]); in-hospital length of stay decreased from 13.5±15 to 12.7±11 days (mean±standard deviation; P=.01); 9 [7-13] to 9 [7-11] (median [Q1-Q3]), in pre-IMCU-CS to post-IMCU-CS, respectively. There were no statistically significant differences in in-hospital mortality (4.9% vs 3.5%; P=.28) or 30-day readmission rate (4.3% vs 4.2%; P=.89).

CONCLUSIONS

After the establishment of an IMCU-CS for postoperative cardiac surgery, there was a reduction in ICU and in-hospital mean lengths of stay with no increase in in-hospital mortality or 30-day readmissions.

What is the Long-term Economic Societal Effect of Periprosthetic Infections After THA? A Markov Analysis

BACKGROUND

Current estimates for the direct costs of a single episode of care for periprosthetic joint infection (PJI) after THA are approximately USD 100,000. These estimates do not account for the costs of failed treatments and do not include indirect costs such as lost wages.

QUESTIONS/PURPOSES

The goal of this study was to estimate the long-term economic effect to society (direct and indirect costs) of a PJI after THA treated with contemporary standards of care in a hypothetical patient of working age (three scenarios, age 55, 60, and 65 years).

METHODS

We created a state-transition Markov model with health states defined by surgical treatment options including irrigation and débridement with modular exchange, single-stage revision, and two-stage revision. Reoperation rates attributable to septic and aseptic failure modes and indirect and direct costs were calculated estimates garnered via multiple systematic reviews of peer-reviewed orthopaedic and infectious disease journals and Medicare reimbursement data. We conducted an analysis over a hypothetical patient's lifetime from the societal perspective with costs discounted by 3% annually. We conducted sensitivity analysis to delineate the effects of uncertainty attributable to input variables.

RESULTS

The model found a base case cost of USD 390,806 per 65-year-old patient with an infected THA. One-way sensitivity analysis gives a range of USD 389,307 (65-year-old with a 3% reinfection rate) and USD 474,004 (55-year-old with a 12% reinfection rate). Indirect costs such as lost wages make up a considerable portion of the costs and increase considerably as age at the time of infection decreases.

CONCLUSIONS

The results of this study show that the overall treatment of a periprosthetic infection after a THA is markedly more expensive to society than previously estimated when accounting for the considerable failure rates of current treatment options and including indirect costs. These overall costs, combined with a large projected increase in THAs and a steady state of septic failures, should be taken into account when considering the total cost of THA. Further research is needed to adequately compare the clinical and economic effectiveness of alternative treatment pathways.

LEVEL OF EVIDENCE

Level II, economic and decision analysis.

Lack of Association between Preoperative Statin Use and Respiratory and Neurologic Complications after Cardiac Surgery

Background

Statins may reduce the risk of pulmonary and neurologic complications after cardiac surgery.

Methods

The authors acquired data for adults who had coronary artery bypass graft, valve surgery, or combined procedures. The authors matched patients who took statins preoperatively to patients who did not. First, the authors assessed the association between preoperative statin use and the primary outcomes of prolonged ventilation (more than 24 h), pneumonia (positive cultures of sputum, transtracheal fluid, bronchial washings, and/or clinical findings consistent with the diagnosis of pneumonia), and in-hospital all-cause mortality, using logistic regressions. Second, the authors analyzed the collapsed composite of neurologic complications using logistic regression. Intensive care unit and hospital length of stay were evaluated with Cox proportional hazard models.

Results

Among 14,129 eligible patients, 6,642 patients were successfully matched. There was no significant association between preoperative statin use and prolonged ventilation (statin: 408/3,321 [12.3%] vs. nonstatin: 389/3,321 [11.7%]), pneumonia (44/3,321 [1.3%] vs. 54/3,321 [1.6%]), and in-hospital mortality (52/3,321 [1.6%] vs. 43/3,321 [1.3%]). The estimated odds ratio was 1.06 (98.3% CI, 0.88 to 1.27) for prolonged ventilation, 0.81 (0.50 to 1.32) for pneumonia, and 1.21 (0.74 to 1.99) for in-hospital mortality. Neurologic outcomes were not associated with preoperative statin use (53/3,321 [1.6%] vs. 56/3,321 [1.7%]), with an odds ratio of 0.95 (0.60 to 1.50). The length of intensive care unit and hospital stay was also not associated with preoperative statin use, with a hazard ratio of 1.04 (0.98 to 1.10) for length of hospital stay and 1.00 (0.94 to 1.06) for length of intensive care unit stay.

Conclusions

Preoperative statin use did not reduce pulmonary or neurologic complications after cardiac surgery.

Atrial fibrillation after cardiac surgery: Prevention and management: The Australasian experience

Background

Atrial fibrillation (AF) after cardiac surgery is a major health problem that is associated with a significant financial burden. This paper aims to highlight this problem and review the current guidelines in the prevention and management of AF after cardiac surgery, providing our experience in the Australasian centers.

Methods

We conducted a literature review using mainly PubMed to compare the current practice with the available evidence. EMBASE and Cochrane library were also searched. We concurrently developed an online questionnaire to collect data from other Australasian centers regarding their approach to this problem.

Results

We identified 194 studies that were considered relevant to our research. We did not find any formal protocols published in the literature. From our Australasian experience; seven centers (58%) had a protocol for AF prophylaxis. The protocols included electrolytes replacement, use of amiodarone and/or β-blockers. Other strategies were occasionally used but were not part of a structured protocol.

Conclusion

The development of an integrated medical and surgical protocol for the prophylaxis of AF after cardiac surgery is an important aspect for the care of postoperative cardiac patients. Considerations of prophylactic strategies other than those routinely used should be included in the protocol. This area should receive considerable attention in order to reduce the postoperative complications and health costs.

Examining Health Care Costs: Opportunities to Provide Value in the Intensive Care Unit

As health care costs threaten the economic stability of American society, increasing pressures to focus on value-based health care have led to the development of protocols for fast-track cardiac surgery and for delirium management. Critical care services can be led by anesthesiologists with the goal of improving ICU outcomes and at the same time decreasing the rising cost of ICU medicine.

The Genetic Determinants of Renal Impairment Following Cardiac Surgery

Cardiac surgery is frequently performed, and acute renal dysfunction is a common adverse event following this procedure. Cardiac surgery-related renal injury independently predicts longer hospital stays and greater rates of morbidity and mortality. Although much work has been completed toward better understanding of this phenomenon, the state of knowledge concerning surgery-related renal injury remains limited. Currently, there is no effective paradigm to identify patients who are at risk for this condition; the specific mechanisms of renal injury during surgery are incompletely understood; and few therapies exist to prevent or treat this phenomenon. To better understand this common clinical problem, recent research has focused on the importance of genetic variability within the physiological and patho-physiological systems that underlie renal dysfunction following cardiac surgery. Emphasizing the importance of using genetics to elucidate molecular mechanisms of this disease, this article reviews the current literature on genetic polymorphisms and post cardiac surgery-related renal dysfunction.

Pulmonary Complications After Cardiac Surgery

Over the past two decades there has been a steady evolution in the practice of adult cardiac surgery with the introduction of “off-pump” surgery. However, respiratory complications remain a leading cause of postcardiac surgical morbidity and can prolong hospital stays and increase costs. The high incidence of pulmonary complications is in part due to the disruption of normal ventilatory function that is inherent to surgery in the thoracic region. Furthermore, patients undergoing such surgery often have underlying illnesses such as intrinsic lung disease (e.g., chronic obstructive pulmonary disease) and pulmonary dysfunction secondary to cardiac disease (e.g., congestive heart failure) that increase their susceptibility to postoperative respiratory problems. Given that many patients undergoing cardiac surgery are thus susceptiple to pulmonary complications, it is remarkable that more patients do not suffer from them during and after cardiac surgery. This is to a large degree because of advances in anesthetic, surgical and critical care that, for example, have reduced the physiological insults of surgery (e.g., better myocardial preservation techniques) and streamlined care in the immediate postoperative period (e.g., early extubation). Moreover, the development of minimally invasive surgery and nonbypass techniques are further evidence of the attempts at reducing the homeostatic disruptions of cardiac surgery. This review examines the available information on the incidences, consequences, and treatments of postcardiac surgery respiratory complications.

A Prospective Study of Outcomes, Healthcare Resource Utilization, and Costs Associated With Postoperative Nosocomial Infections

Objective.

We evaluated 4 important outcomes associated with postoperative nosocomial infection: costs, mortality, excess length of stay, and utilization of healthcare resources.

Design.

The outcomes for patients who underwent general, cardiothoracic, and neurosurgical operations were recorded during a previous clinical trial. Multivariable analyses including significant covariates were conducted to determine whether nosocomial infection significantly affected the outcomes.

Setting.

A large tertiary care medical center and an affiliated Veterans Affairs Medical Center.

Patients.

A total of 3,864 surgical patients.

Results.

The overall nosocomial infection rate was 11.3%. Important covariates included age, Karnofsky score, McCabe and Jackson classification of the severity of underlying disease, National Nosocomial Infection Surveillance system risk index, and number of comorbidities. After accounting for covariates, nosocomial infection was associated with increased postoperative length of stay, increased costs, increased hospital readmission rate, and increased use of antimicrobial agents in the outpatient setting. Nosocomial infection was not associated independently with a significantly increased risk of death in this surgical population.

Conclusion.

Postoperative nosocomial infection was associated with increased costs of care and with increased utilization of medical resources. To accurately assess the effects of nosocomial infections, one must take into account important covariates. Surgeons seeking to decrease the cost of care and resource utilization must identify ways to decrease the rate of postoperative nosocomial infection.

Recombinant activated factor VII for uncontrolled bleeding postcardiac surgery

A retrospective observational study to review the safety and efficacy of rFVIIa in persistent hemorrhage in post cardiac surgical patients.

Methods

Patients who had bleeding of 3 ml/kg/h or more for 2 consecutive hours after cardiac surgery were arranged into two groups; control group, who received conventional treatment and rFVIIa group, who received conventional treatment and rFVIIa.

Results

There was no significant difference in demographic and surgical characteristics of both groups. The chest tube output significantly decreased in the rFVIIa group compared to the other group 4 hours after admission {1.4 (IQR: 1–2.2) ml/kg/h vs 3.9 (IQR: 3.1–5.6) ml/kg/h; p = 0.004} and continues to be significant till 9 hours after CSICU admission {0.6 (IQR: 0.4–1.1) ml/kg/h vs 1.9 (IQR: 1.2–2.2) ml/kg/h; p = 0.04}. The median number of blood products units transfused to rFVIIa group was significantly lower compared to control group in the period from 3–12 hours after CSICU admission. 13 (5.5%) patients in rFVIIa group had Thromboembolic adverse events (TAE) compared to 7 (2.4%) patients in other group p = 0.27. 8 patients in the rFVIIa group needed reexploration compared to 19 patients in the other group, p = 0.01. No significant difference was noticed between the 2 groups regarding: new onset renal failure, median number of mechanical ventilator days, pneumonia, mediastinitis, ICU and hospital lengths of stay, survival at 30 days and at discharge.

Conclusion

In this analysis, rFVIIa succefully reduced the chest tube bleeding and blood products transfused during severe post cardiac surgical bleeding. However, safety of rFVIIa remains unclear. Prospective controlled trials are still needed to confirm the role of rFVIIa.

Costs Associated With Surgical Site Infections in Veterans Affairs Hospitals

IMPORTANCE

Surgical site infections (SSIs) are potentially preventable complications that are associated with excess morbidity and mortality.

OBJECTIVE

To determine the excess costs associated with total, deep, and superficial SSIs among all operations and for high-volume surgical specialties.

DESIGN, SETTING, AND PARTICIPANTS

Surgical patients from 129 Veterans Affairs (VA) hospitals were included. The Veterans Health Administration Decision Support System and VA Surgical Quality Improvement Program databases were used to assess costs associated with SSIs among VA patients who underwent surgery in fiscal year 2010.

MAIN OUTCOMES AND MEASURES

Linear mixed-effects models were used to evaluate incremental costs associated with SSIs, controlling for patient risk factors, surgical risk factors, and hospital-level variation in costs. Costs of the index hospitalization and subsequent 30-day readmissions were included. Additional analysis determined potential cost savings of quality improvement programs to reduce SSI rates at hospitals with the highest risk-adjusted SSI rates.

RESULTS

Among 54,233 VA patients who underwent surgery, 1756 (3.2%) experienced an SSI. Overall, 0.8% of the cohort had a deep SSI, and 2.4% had a superficial SSI. The mean unadjusted costs were $31,580 and $52,620 for patients without and with an SSI, respectively. In the risk-adjusted analyses, the relative costs were 1.43 times greater for patients with an SSI than for patients without an SSI (95% CI, 1.34-1.52; difference, $11,876). Deep SSIs were associated with 1.93 times greater costs (95% CI, 1.71-2.18; difference, $25,721), and superficial SSIs were associated with 1.25 times greater costs (95% CI, 1.17-1.35; difference, $7003). Among the highest-volume specialties, the greatest mean cost attributable to SSIs was $23,755 among patients undergoing neurosurgery, followed by patients undergoing orthopedic surgery, general surgery, peripheral vascular surgery, and urologic surgery. If hospitals in the highest 10th percentile (ie, the worst hospitals) reduced their SSI rates to the rates of the hospitals in the 50th percentile, the Veterans Health Administration would save approximately $6.7 million per year.

CONCLUSIONS AND RELEVANCE

Surgical site infections are associated with significant excess costs. Among analyzed surgery types, deep SSIs and SSIs among neurosurgery patients are associated with the highest risk-adjusted costs. Large potential savings per year may be achieved by decreasing SSI rates.

Risk factors for transient dysfunction of gas exchange after cardiac surgery

Objective

A retrospective cohort study was preformed aiming to verify the presence of transient dysfunction of gas exchange in the postoperative period of cardiac surgery and determine if this disorder is linked to cardiorespiratory events.

Methods

We included 942 consecutive patients undergoing cardiac surgery and cardiac procedures who were referred to the Intensive Care Unit between June 2007 and November 2011.

Results

Fifteen patients had acute respiratory distress syndrome (2%), 199 (27.75%) had mild transient dysfunction of gas exchange, 402 (56.1%) had moderate transient dysfunction of gas exchange, and 39 (5.4%) had severe transient dysfunction of gas exchange. Hypertension and cardiogenic shock were associated with the emergence of moderate transient dysfunction of gas exchange postoperatively (P=0.02 and P=0.019, respectively) and were risk factors for this dysfunction (P=0.0023 and P=0.0017, respectively). Diabetes mellitus was also a risk factor for transient dysfunction of gas exchange (P=0.03). Pneumonia was present in 8.9% of cases and correlated with the presence of moderate transient dysfunction of gas exchange (P=0.001). Severe transient dysfunction of gas exchange was associated with patients who had renal replacement therapy (P=0.0005), hemotherapy (P=0.0001), enteral nutrition (P=0.0012), or cardiac arrhythmia (P=0.0451).

Conclusion

Preoperative hypertension and cardiogenic shock were associated with the occurrence of postoperative transient dysfunction of gas exchange. The preoperative risk factors included hypertension, cardiogenic shock, and diabetes. Postoperatively, pneumonia, ventilator-associated pneumonia, renal replacement therapy, hemotherapy, and cardiac arrhythmia were associated with the appearance of some degree of transient dysfunction of gas exchange, which was a risk factor for reintubation, pneumonia, ventilator-associated pneumonia, and renal replacement therapy in the postoperative period of cardiac surgery and cardiac procedures.

Transfusion strategy: impact of haemodynamics and the challenge of haemodilution

Blood transfusion is associated with increased morbidity and mortality and numerous reports have emphasised the need for reduction. Following this there is increased attention to the concept of patient blood management. However, bleeding is relatively common following cardiac surgery and is further enhanced by the continued antiplatelet therapy policy. Another important issue is that cardiopulmonary bypass leads to haemodilution and a potential blood loss. The basic role of blood is oxygen transport to the organs. The determining factors of oxygen delivery are cardiac output, haemoglobin, and saturation. If oxygen delivery/consumption is out of balance, the compensation mechanisms are simple, as a decrease in one factor results in an increase in one or two other factors. Patients with coexisting cardiac diseases may be of particular risk, but studies indicate that patients with coexisting cardiac diseases tolerate moderate anaemia and may even benefit from a restrictive transfusion regimen. Further it has been shown that patients with reduced left ventricular function are able to compensate with increased cardiac output in response to bleeding and haemodilution if normovolaemia is maintained. In conclusion the evidence supports that each institution establishes its own patient blood management strategy to both conserve blood products and maximise outcome.

Role of topical application of gentamicin containing collagen implants in cardiac surgery

Sternal wound infections (SWI) continue to be a major cause of concern after cardiac surgery. It leads to prolonged hospital stay and increased morbidity, mortality and increased hospital costs. Prophylactic systemic antibiotics have been used to prevent surgical site infection (SSI). However, prolonged postoperative use of systemic antibiotics can lead to emergence of resistant organisms. Gentamycin Containing Collagen Implants (GCCI) when used during sternotomy closure produces high local antibiotic concentrations in the wound with a low serum concentration. There is evidence that the concentration of gentamicin in the mediastinal fluid reaches levels high enough to be effective against bacteria that are considered resistant to gentamycin and other antibiotics.However, questions have been raised about the safety and efficacy of GCCI. There were concerns whether GCCI can lead to systemic absorption with renal impairment and whether use of topical antibiotics can lead to emergence of antimicrobial resistance.We, hereby, review the literature on GCCI (Collatamp) and take the opportunity to appraise the scientific community about their role in cardiac surgery. Several recent studies have supported their clinical effectiveness. They should be used in dry condition and should not be soaked in saline even for a short period prior to use. However, for GCCI to become part of routine practice in cardiac surgery further large randomised studies are required. As the incidence of sternal wound infection is low in the specialty of cardiac surgery, for any study to be sufficiently powered to address this issue, multicenter studies might be the way forward.Based on the evidence presented in this manuscript it is recommended GCCI (Collatamp) can be a cost effective adjunct for prevention of sternal wound infection. They can also be used for treatment of Deep Sternal Wound Infection.

Preoperative mild cognitive dysfunction predicts pulmonary complications after coronary artery bypass graft surgery

OBJECTIVES

In elderly patients with mild cognitive impairment, noncompliance with respiratory exercises, ineffective expectoration, reluctance in mobilization, and difficulty in learning the use of drugs such as inhalers were observed in the early postoperative period after coronary artery bypass graft surgery. It was hypothesized that respiratory complications may be more frequent in these patients, and so the postoperative respiratory complications in patients with preoperative mild cognitive impairment were compared with the postoperative respiratory complications of a control group.

DESIGN

A prospective cohort control.

SETTING

A university hospital.

PARTICIPANTS

Patients undergoing elective coronary artery bypass graft surgery.

INTERVENTIONS

Investigators separated 48 patients>70 years old who were scheduled for elective coronary artery bypass graft surgery into two groups: patients with preoperative mild cognitive impairment (group A, n = 25) and patients with no cognitive impairment (control group; group B, n = 23). The patients' cognitive status was evaluated preoperatively by the Montreal Cognitive Assessment test.

MEASUREMENTS AND MAIN RESULTS

Pulmonary functions and respiratory complications were evaluated via chest x-rays and spirometry tests preoperatively and postoperatively. A significant difference was observed between the groups, particularly with regard to atelectasis and prolonged ventilation (p<0.001 and p<0.05). No significant impairment was observed in the spirometry tests of the control group. However, a significant deterioration was observed in the postoperative spirometry tests of patients with preoperative mild cognitive impairment.

CONCLUSIONS

This study suggested that mild cognitive impairment was associated with pulmonary complications after coronary artery bypass graft surgery.

Effectiveness of a bundled intervention of decolonization and prophylaxis to decrease Gram positive surgical site infections after cardiac or orthopedic surgery: systematic review and meta-analysis

OBJECTIVE

To evaluate studies assessing the effectiveness of a bundle of nasal decolonization and glycopeptide prophylaxis for preventing surgical site infections caused by Gram positive bacteria among patients undergoing cardiac operations or total joint replacement procedures.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed (1995 to 2011), the Cochrane database of systematic reviews, CINAHL, Embase, and clinicaltrials.gov were searched to identify relevant studies. Pertinent journals and conference abstracts were hand searched. Study authors were contacted if more data were needed.

ELIGIBILITY CRITERIA

Randomized controlled trials, quasi-experimental studies, and cohort studies that assessed nasal decolonization or glycopeptide prophylaxis, or both, for preventing Gram positive surgical site infections compared with standard care.

PARTICIPANTS

Patients undergoing cardiac operations or total joint replacement procedures. DATA EXTRACTION AND STUDY APPRAISAL: Two authors independently extracted data from each paper and a random effects model was used to obtain summary estimates. Risk of bias was assessed using the Downs and Black or the Cochrane scales. Heterogeneity was assessed using the Cochran Q and I(2) statistics.

RESULTS

39 studies were included. Pooled effects of 17 studies showed that nasal decolonization had a significantly protective effect against surgical site infections associated with Staphylococcus aureus (pooled relative risk 0.39, 95% confidence interval 0.31 to 0.50) when all patients underwent decolonization (0.40, 0.29 to 0.55) and when only S aureus carriers underwent decolonization (0.36, 0.22 to 0.57). Pooled effects of 15 prophylaxis studies showed that glycopeptide prophylaxis was significantly protective against surgical site infections related to methicillin (meticillin) resistant S aureus (MRSA) compared with prophylaxis using β lactam antibiotics (0.40, 0.20 to 0.80), and a non-significant risk factor for methicillin susceptible S aureus infections (1.47, 0.91 to 2.38). Seven studies assessed a bundle including decolonization and glycopeptide prophylaxis for only patients colonized with MRSA and found a significantly protective effect against surgical site infections with Gram positive bacteria (0.41, 0.30 to 0.56).

CONCLUSIONS

Surgical programs that implement a bundled intervention including both nasal decolonization and glycopeptide prophylaxis for MRSA carriers may decrease rates of surgical site infections caused by S aureus or other Gram positive bacteria.

Interventions for preventing post-operative atrial fibrillation in patients undergoing heart surgery

BACKGROUND

Atrial fibrillation is a common post-operative complication of cardiac surgery and is associated with an increased risk of post-operative stroke, increased length of intensive care unit and hospital stays, healthcare costs and mortality. Numerous trials have evaluated various pharmacological and non-pharmacological prophylactic interventions for their efficacy in preventing post-operative atrial fibrillation. We conducted an update to a 2004 Cochrane systematic review and meta-analysis of the literature to gain a better understanding of the effectiveness of these interventions.

OBJECTIVES

The primary objective was to assess the effects of pharmacological and non-pharmacological interventions for preventing post-operative atrial fibrillation or supraventricular tachycardia after cardiac surgery. Secondary objectives were to determine the effects on post-operative stroke or cerebrovascular accident, mortality, cardiovascular mortality, length of hospital stay and cost of treatment during the hospital stay.

SEARCH METHODS

We searched the Cochrane Central Register of ControlLed Trials (CENTRAL) (Issue 8, 2011), MEDLINE (from 1946 to July 2011), EMBASE (from 1974 to July 2011) and CINAHL (from 1981 to July 2011).

SELECTION CRITERIA

We selected randomized controlled trials (RCTs) that included adult patients undergoing cardiac surgery who were allocated to pharmacological or non-pharmacological interventions for the prevention of post-operative atrial fibrillation or supraventricular tachycardia, except digoxin, potassium (K(+)), or steroids.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted study data and assessed trial quality.

MAIN RESULTS

One hundred and eighteen studies with 138 treatment groups and 17,364 participants were included in this review. Fifty-seven of these studies were included in the original version of this review while 61 were added, including 27 on interventions that were not considered in the original version. Interventions included amiodarone, beta-blockers, sotalol, magnesium, atrial pacing and posterior pericardiotomy. Each of the studied interventions significantly reduced the rate of post-operative atrial fibrillation after cardiac surgery compared with a control. Beta-blockers (odds ratio (OR) 0.33; 95% confidence interval) CI 0.26 to 0.43; I(2) = 55%) and sotalol (OR 0.34; 95% CI 0.26 to 0.43; I(2) = 3%) appear to have similar efficacy while magnesium's efficacy (OR 0.55; 95% CI 0.41 to 0.73; I(2) = 51%) may be slightly less. Amiodarone (OR 0.43; 95% CI 0.34 to 0.54; I(2) = 63%), atrial pacing (OR 0.47; 95% CI 0.36 to 0.61; I(2) = 50%) and posterior pericardiotomy (OR 0.35; 95% CI 0.18 to 0.67; I(2) = 66%) were all found to be effective. Prophylactic intervention decreased the hospital length of stay by approximately two-thirds of a day and decreased the cost of hospital treatment by roughly $1250 US. Intervention was also found to reduce the odds of post-operative stroke, though this reduction did not reach statistical significance (OR 0.69; 95% CI 0.47 to 1.01; I(2) = 0%). No significant effect on all-cause or cardiovascular mortality was demonstrated.

AUTHORS' CONCLUSIONS

Prophylaxis to prevent atrial fibrillation after cardiac surgery with any of the studied pharmacological or non-pharmacological interventions may be favored because of its reduction in the rate of atrial fibrillation, decrease in the length of stay and cost of hospital treatment and a possible decrease in the rate of stroke. However, this review is limited by the quality of the available data and heterogeneity between the included studies. Selection of appropriate interventions may depend on the individual patient situation and should take into consideration adverse effects and the cost associated with each approach.

Preoperative physical therapy for elective cardiac surgery patients

BACKGROUND

After cardiac surgery, physical therapy is a routine procedure delivered with the aim of preventing postoperative pulmonary complications.

OBJECTIVES

To determine if preoperative physical therapy with an exercise component can prevent postoperative pulmonary complications in cardiac surgery patients, and to evaluate which type of patient benefits and which type of physical therapy is most effective.

SEARCH METHODS

Searches were run on the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library (2011, Issue 12 ); MEDLINE (1966 to 12 December 2011); EMBASE (1980 to week 49, 2011); the Physical Therapy Evidence Database (PEDro) (to 12 December 2011) and CINAHL (1982 to 12 December 2011).

SELECTION CRITERIA

Randomised controlled trials or quasi-randomised trials comparing preoperative physical therapy with no preoperative physical therapy or sham therapy in adult patients undergoing elective cardiac surgery.

DATA COLLECTION AND ANALYSIS

Data were collected on the type of study, participants, treatments used, primary outcomes (postoperative pulmonary complications grade 2 to 4: atelectasis, pneumonia, pneumothorax, mechanical ventilation > 48 hours, all-cause death, adverse events) and secondary outcomes (length of hospital stay, physical function measures, health-related quality of life, respiratory death, costs). Data were extracted by one review author and checked by a second review author. Review Manager 5.1 software was used for the analysis.

MAIN RESULTS

Eight randomised controlled trials with 856 patients were included. Three studies used a mixed intervention (including either aerobic exercises or breathing exercises); five studies used inspiratory muscle training. Only one study used sham training in the controls. Patients that received preoperative physical therapy had a reduced risk of postoperative atelectasis (four studies including 379 participants, relative risk (RR) 0.52; 95% CI 0.32 to 0.87; P = 0.01) and pneumonia (five studies including 448 participants, RR 0.45; 95% CI 0.24 to 0.83; P = 0.01) but not of pneumothorax (one study with 45 participants, RR 0.12; 95% CI 0.01 to 2.11; P = 0.15) or mechanical ventilation for > 48 hours after surgery (two studies with 306 participants, RR 0.55; 95% CI 0.03 to 9.20; P = 0.68). Postoperative death from all causes did not differ between groups (three studies with 552 participants, RR 0.66; 95% CI 0.02 to 18.48; P = 0.81). Adverse events were not detected in the three studies that reported on them. The length of postoperative hospital stay was significantly shorter in experimental patients versus controls (three studies with 347 participants, mean difference -3.21 days; 95% CI -5.73 to -0.69; P = 0.01). One study reported a reduced physical function measure on the six-minute walking test in experimental patients compared to controls. One other study reported a better health-related quality of life in experimental patients compared to controls. Postoperative death from respiratory causes did not differ between groups (one study with 276 participants, RR 0.14; 95% CI 0.01 to 2.70; P = 0.19). Cost data were not reported on.

AUTHORS' CONCLUSIONS

Evidence derived from small trials suggests that preoperative physical therapy reduces postoperative pulmonary complications (atelectasis and pneumonia) and length of hospital stay in patients undergoing elective cardiac surgery. There is a lack of evidence that preoperative physical therapy reduces postoperative pneumothorax, prolonged mechanical ventilation or all-cause deaths.

Intravenous magnesium prevents atrial fibrillation after coronary artery bypass grafting: a meta-analysis of 7 double-blind, placebo-controlled, randomized clinical trials

Background

Postoperative atrial fibrillation (POAF) is the most common complication after coronary artery bypass grafting (CABG). The preventive effect of magnesium on POAF is not well known. This meta-analysis was undertaken to assess the efficacy of intravenous magnesium on the prevention of POAF after CABG.

Methods

Eligible studies were identified from electronic databases (Medline, Embase, and the Cochrane Library). The primary outcome measure was the incidence of POAF. The meta-analysis was performed with the fixed-effect model or random-effect model according to heterogeneity.

Results

Seven double-blind, placebo-controlled, randomized clinical trials met the inclusion criteria including 1,028 participants. The pooled results showed that intravenous magnesium reduced the incidence of POAF by 36% (RR 0.64; 95% confidence interval (CI) 0.50-0.83; P = 0.001; with no heterogeneity between trials (heterogeneity P = 0.8, I² = 0%)).

Conclusions

This meta-analysis indicates that intravenous magnesium significantly reduces the incidence of POAF after CABG. This finding encourages the use of intravenous magnesium as an alternative to prevent POAF after CABG. But more high quality randomized clinical trials are still need to confirm the safety.

Oxygen delivery through high-flow nasal cannulae increase end-expiratory lung volume and reduce respiratory rate in post-cardiac surgical patients

BACKGROUND

High-flow nasal cannulae (HFNCs) create positive oropharyngeal airway pressure, but it is unclear how their use affects lung volume. Electrical impedance tomography allows the assessment of changes in lung volume by measuring changes in lung impedance. Primary objectives were to investigate the effects of HFNC on airway pressure (P(aw)) and end-expiratory lung volume (EELV) and to identify any correlation between the two. Secondary objectives were to investigate the effects of HFNC on respiratory rate, dyspnoea, tidal volume, and oxygenation; and the interaction between BMI and EELV.

METHODS

Twenty patients prescribed HFNC post-cardiac surgery were investigated. Impedance measures, P(aw), ratio, respiratory rate, and modified Borg scores were recorded first on low-flow oxygen and then on HFNC.

RESULTS

A strong and significant correlation existed between P(aw) and end-expiratory lung impedance (EELI) (r=0.7, P<0.001). Compared with low-flow oxygen, HFNC significantly increased EELI by 25.6% [95% confidence interval (CI) 24.3, 26.9] and P(aw) by 3.0 cm H(2)O (95% CI 2.4, 3.7). Respiratory rate reduced by 3.4 bpm (95% CI 1.7, 5.2) with HFNC use, tidal impedance variation increased by 10.5% (95% CI 6.1, 18.3), and ratio improved by 30.6 mm Hg (95% CI 17.9, 43.3). A trend towards HFNC improving subjective dyspnoea scoring (P=0.023) was found. Increases in EELI were significantly influenced by BMI, with larger increases associated with higher BMIs (P<0.001).

CONCLUSIONS

This study suggests that HFNCs reduce respiratory rate and improve oxygenation by increasing both EELV and tidal volume and are most beneficial in patients with higher BMIs.

Costs of hospital-acquired infection and transferability of the estimates: a systematic review

Hospital-acquired infections (HAIs) present a substantial problem for healthcare providers, with a relatively high frequency of occurrence and considerable damage caused. There has been an increase in the number of cost-effectiveness and cost-savings analyses of HAI control measures, and the quantification of the cost of HAI (COHAI) is necessary for such calculations. While recent guidelines allow researchers to utilize COHAI estimates from existing published literature when evaluating the economic impact of HAI control measures, it has been observed that the results of economic evaluations may not be directly applied to other jurisdictions due to differences in the context and circumstances in which the original results were produced. The aims of this study were to conduct a systematic review of published studies that have produced COHAI estimates from 1980 to 2006 and to evaluate the quality of these estimates from the perspective of transferability. From a total of 89 publications, only eight papers (9.0%) had a high level of transferability in which all components of costs were described, data for costs in each component were reported, and unit costs were estimated with actual costing. We also did not observe a higher citation level for studies with high levels of transferability. We feel that, in order to ensure an appropriate contribution to the infection control program decision-making process, it is essential for researchers who estimate COHAI, analysts who use COHAI estimates for decision-making, as well as relevant journal reviewers and editors to recognize the importance of a transferability paradigm.

Warm-blood cardioplegia with low or high magnesium for coronary bypass surgery: a randomised controlled trial

Objective: Magnesium (Mg²⁺) is cardioprotective and has been routinely used to supplement cardioplegic solutions during coronary artery bypass graft (CABG) surgery. However, there is no consensus about the Mg²⁺ concentration that should be used. The aim of this study was to compare the effects of intermittent antegrade warm-blood cardioplegia supplemented with either low- or high-concentration Mg²⁺. Methods: This study was a randomised controlled trial carried out in two cardiac surgery centres, Bristol, UK and Cuneo, Italy. Patients undergoing isolated CABG with cardiopulmonary bypass were eligible. Patients were randomised to receive warm-blood cardioplegia supplemented with 5 or 16 mmol l⁻¹ Mg²⁺. The primary outcome was postoperative atrial fibrillation. Secondary outcomes were serum biochemical markers (troponin I, Mg²⁺, potassium, lactate and creatinine) and time-to-plegia arrest. Intra-operative and postoperative clinical outcomes were also recorded. Results: Data from two centres for 691 patients (342 low and 349 high Mg²⁺) were analysed. Baseline characteristics were similar for both groups. There was no significant difference in the frequency of postoperative atrial fibrillation in the high (32.8%) and low (32.0%) groups (risk ratio 1.03, 95% confidence interval, CI, 0.82–1.28). However, compared with the low group, troponin I release was 28% less (95% CI 55–94%, p = 0.02) in the high-Mg²⁺ group. The 30-day mortality was 0.72% (n = 5); all deaths occurred in the high-Mg²⁺ group but there was no significant difference between the groups (p = 0.06). Frequencies of other major complications were similar in the two groups. Conclusions: Warm-blood cardioplegia supplemented with 16 mmol l⁻¹ Mg²⁺, compared with 5 mmol l⁻¹ Mg²⁺, does not reduce the frequency of postoperative atrial fibrillation in patients undergoing CABG but may reduce cardiac injury. (This trial was registered as ISRCTN95530505.)

The role of topical antibiotics used as prophylaxis in surgical site infection prevention

Compared with systemic antibiotic therapy, the topical or local delivery of an antibiotic has many potential advantages. However, local antibiotics at the surgical site have received very limited approval in any of the surgical prophylaxis consensus guidelines that we are aware of. A review of the literature was carried out through searches of peer-reviewed publications in PubMed in the English language over a 30 year period between January 1980 and May 2010. Both retrospective and prospective studies were included, as well as meta-analyses. With regard to defining 'topical' or 'local' antibiotic application, the application of an antibiotic solution to the surgical site intraoperatively or immediately post-operatively was included. A number of surgical procedures have been shown to significantly benefit from perioperative topical prophylaxis, e.g. joint arthroplasty, cataract surgery and, possibly, breast augmentation. In obese patients undergoing abdominal surgery, topical surgical prophylaxis is also proven to be beneficial. The selective use of topical antibiotics as surgical prophylaxis is justified for specific procedures, such as joint arthroplasty, cataract surgery and, possibly, breast augmentation. In selective cases, such as obese patients undergoing abdominal surgery, topical surgical prophylaxis is also proven to be beneficial. Apart from these specific indications, the evidence for use of topical antibiotics in surgery is lacking in conclusive randomized controlled trials.

Sternal wound reconstruction: management in different cardiac populations

Poststernotomy mediastinitis is a feared complication for patients undergoing cardiac surgery associated with high rates of morbidity and mortality. Approximately 15% of patients will ultimately be readmitted for a recurrent sternal wound infection. The objective of this study is to review a large single surgeon experience with sternal wound patients managed with a variety of soft tissue flaps to assess mitigating factors, involved organisms, and treatment protocols as related to specific cardiac populations. Records for 136 sternal reconstruction patients treated from January 2000 to July 2007 were evaluated. Patients underwent a variety of cardiac surgeries including coronary artery bypass grafting (CABG), valve replacement, aortic reconstruction, heart transplantation, lung transplantation, and combinations of these procedures. A total of 39.2% of patients developed a sternal wound during the same admission as their cardiac surgery, at an average of 16.1 days. This rate was only 6% for CABG-only patients and rose to nearly 50% in heart transplant and CABG + valve patients. A total of 78.6% of heart transplant patients with a sternal wound had a history of ventricular assist device and 41% of all patients had at least 1 previous sternotomy. Thirteen patients (9.6%) had 1 or more recurrent infections requiring surgery; 50% occurring in transplant patients, most of whom had diabetes and/or renal insufficiency. The most common presenting symptom was drainage (n = 75, 55.6%) or wound dehiscence (n = 22, 16.3%). Twenty-five different organisms were identified; 26 patients (18.5%) had multiple organisms. Staphylococcus species were most common. Plastic surgery intervention occurred on average 109.2 days after cardiac surgery. CABG and CABG + valve patients most frequently received right pectoralis muscle turnover flaps or left pectoralis muscle advancement flaps. Ten heart transplant patients (37.0%) underwent omental flaps. The 30-day perioperative mortality rate was 13 patients (9.6%).

Cost effectiveness of local collagen-gentamicin as prophylaxis for sternal wound infections in different risk groups

OBJECTIVES

In a randomized trial addition of local collagen-gentamicin in the sternal wound reduced the rate of sternal wound infection (SWI) to about 50% compared to intravenous prophylaxis alone. The aim of the present study was to evaluate the economic rationale for its use in every-day clinical practice. This includes the question whether high-risk groups that may have particular benefit should be identified.

DESIGN

For each patient with SWI in the trial the costs attributable to the SWI were calculated. Risk factors for SWI were identified and any heterogeneity of the effect of the prophylaxis examined.

RESULTS

The mean cost of a SWI was about 14500 Euros. A cost effectiveness analysis showed that the prophylaxis was cost saving. The positive net balance was even higher in risk groups. Assignment to the control group, overweight, diabetes, younger age, mammarian artery use, left ventricular ejection fraction <35% and longer operation time were independent risk factors for infection.

CONCLUSION

The addition of local collagen-gentamicin to intravenous antibiotic prophylaxis was dominant, i.e. resulted in both lower costs and fewer wound infections.

Patients' experiences of mediastinitis after coronary artery bypass graft procedure

Few studies have focussed on patients' experiences of and suffering due to mediastinitis following Coronary Artery by-pass Graft (CABG). Mediastinitis creates a complex and invasive experience for the patient with prolonged hospitalisation, and would be expected to be a significant stressor. The aim of the present study was to capture patients' experiences of the medical and nursing care they received for mediastinitis following CABG. Content analysis revealed three themes with regard to how the patients coped with the stress and threats of mediastinitis and its treatment and how they thought it would influence their future life. A first theme centred on physical and psychological discomfort and impact on autonomy. The staff's medical knowledge and the quality of nursing care as well as the patients' understanding of the situation influenced their experience. A second theme was how patients dealt with perceived danger and stress. Coping strategies such as problem solving, information seeking, dissociation, distraction, minimisation and expression of emotion were used to handle the situations. The third theme comprised the patients' belief that the mediastinitis would not affect the outcome of the CABG procedure, even though their confidence in this was influenced by uncertainty about the rehabilitation process.

Does negative pressure wound therapy have a role in preventing poststernotomy wound complications?

BACKGROUND

Sternal wound infection (SWI) remains a devastating complication after cardiac surgery, decreasing long-term and short-term survival. In treating documented SWI, negative pressure wound therapy (NPWT) reduces wound edema and time to definitive closure and improves peristernal blood flow after internal mammary artery (IMA) harvesting. The authors evaluated NPWT as a form of "well wound" therapy in patients at substantial risk for SWI based on existing risk stratification models.

METHODS

Records of 57 adult cardiac surgery patients (September 2006 to April 2008) were reviewed. After preoperative risk assessment, NPWT was instituted on the clean, closed sternotomy immediately after surgery and continued 4 days postoperatively. Adverse postoperative events, including SWI, need for readmission, and other complications, were documented.

RESULTS

Mean age was 60.4 +/- 10 years, and 89.5% were male; 77.2% were obese (mean body mass index 35.3 +/- 6.7), 54.4% were diabetic, and 29 (50.9%) were both obese and diabetic. Coronary artery bypass (CAB) with single IMA was performed in 50.9% of the patients followed in frequency by combined CAB/valve, non-CAB surgery, and CAB with bilateral IMA. Estimated risk for SWI was 6.1 +/- 4%. All patients tolerated NPWT to completion. Thirty-day and in-hospital mortality was 1.8% and unrelated to DSWI. No treatment of SWI was required.

CONCLUSIONS

In this high-risk cohort, 3 postoperative SWI cases were anticipated but may have been mitigated by NPWT. This is an easily applied and well-tolerated therapy and may stimulate more effective wound healing. Among patients with increased SWI risk, strong consideration should be given to NPWT as a form of "well wound" therapy.

Does physiotherapy reduce the incidence of postoperative complications in patients following pulmonary resection via thoracotomy? a protocol for a randomised controlled trial

BACKGROUND

Postoperative pulmonary and shoulder complications are important causes of postoperative morbidity following thoracotomy. While physiotherapy aims to prevent or minimise these complications, currently there are no randomised controlled trials to support or refute effectiveness of physiotherapy in this setting.

METHODS/DESIGN

This single blind randomised controlled trial aims to recruit 184 patients following lung resection via open thoracotomy. All subjects will receive a preoperative physiotherapy information booklet and following surgery will be randomly allocated to a Treatment Group receiving postoperative physiotherapy or a Control Group receiving standard care nursing and medical interventions but no physiotherapy. The Treatment Group will receive a standardised daily physiotherapy programme to prevent respiratory and musculoskeletal complications. On discharge Treatment Group subjects will receive an exercise programme and exercise diary to complete. The primary outcome measure is the incidence of postoperative pulmonary complications, which will be determined on a daily basis whilst the patient is in hospital by a blinded assessor. Secondary outcome measures are the length of postoperative hospital stay, severity of pain, shoulder function as measured by the self-reported shoulder pain and disability index, and quality of life measured by the Medical Outcomes Study Short Form 36 v2 New Zealand standard version. Pain, shoulder function and quality of life will be measured at baseline, on discharge from hospital, one month and three months postoperatively. Additionally a subgroup of subjects will have measurement of shoulder range of movement and muscle strength by a blinded assessor.

DISCUSSION

Results from this study will contribute to the increasing volume of evidence regarding the effectiveness of physiotherapy following major surgery and will guide physiotherapists in their interventions for patients following thoracotomy.

TRIAL REGISTRATION

The study protocol is registered with the Australian and New Zealand Clinical Trials registry (ANZCTRN12605000201673).

Outcomes in the management of sternal dehiscence by plastic surgery: a ten-year review in one university center

PURPOSE

Infection rates following median sternotomy vary between 0.2% and 10%. These cases are associated with morbidity and mortality rates between 10% and 25% and 5% and 20%, respectively. The purpose of this study was to evaluate patient outcomes following plastic surgery correction of sternotomy dehiscence (SD).

METHODS

All patients operated on for an SD following coronary artery bypass graft surgery (CABG), between 1995 and 2005, with 1 or more flaps, were included.

RESULTS

Eighty cases were identified over a 10-year period. The mean age was 64 (+/-9.1) years. Two or more procedures were required in 17.5% of patients, and the mortality rate within 30 days was 12.5%. Significant variability was revealed between the cumulative mortality rates of plastic surgeons, from 0.0% to 50.0%. Multiple associations were identified for poor outcome, including chronic renal insufficiency and early mortality, and obesity with risk of reintervention.

CONCLUSION

Although patients who undergo surgical correction of a deep sternal infection usually tolerate their intervention well, the mortality within 30 days remains high. This study has identified several factors explaining morbidity and mortality in this patient population.

Aspirin and Tranexamic Acid for Coronary Artery Surgery (ATACAS) Trial: rationale and design

BACKGROUND

Despite some concern that recent aspirin ingestion increases blood loss after coronary artery surgery, there is some evidence that this may reduce thrombotic complications. In contrast, antifibrinolytic drugs can reduce blood loss in this setting, but there is concern that they may increase thrombotic complications. Published guidelines are limited by a lack of large randomized trials addressing the risks and benefits of each of these commonly used therapies in cardiac surgery. The ATACAS Trial is a study comparing aspirin, tranexamic acid, or both, with placebo in patients undergoing on-pump or off-pump coronary artery surgery.

METHODS

We discuss the rationale for conducting ATACAS, a 4600-patient, multicenter randomized trial in at-risk coronary artery surgery, and the features of the ATACAS study design (objectives, end points, target population, allocation, treatments, patient follow-up, and analysis).

CONCLUSIONS

The ATACAS Trial will be the largest study yet conducted to ascertain the benefits and risks of aspirin and antifibrinolytic therapy in coronary artery surgery. Results of the trial will guide the routine clinical care of patients in this setting.

Factors predicting postoperative infectious complications and early induction of inflammatory mediators in ulcerative colitis patients

BACKGROUND

Positive outcomes after restorative proctocolectomy are compromised by a number of specific septic complications. However, there is no useful perioperative marker predicting postoperative infectious complications (PICs) in steroid overdosed patients with ulcerative colitis (UC).

METHODS

To determine factors associated with PICs and their relation to circulating levels of pro- and anti-inflammatory cytokines and neutrophil elastase (NE), we obtained perioperative blood samples from 60 UC patients.

RESULTS

Postoperative infectious complications were identified in 47% of cases. Patients who developed PICs had significantly longer disease duration, had been administered a greater total preoperative dosage of prednisolone, and had a higher body mass index. Logistic regression analysis showed that the total preoperative dosage of prednisolone was independently associated with the development of PICs. These patients showed suppressed systemic inflammation and pro- and anti-inflammatory cytokine induction. An early increase in the NE level was found to be predictive of PICs in the high-dose group, whereas there was no significant difference in neutrophil counts between the high- and low-dose groups.

CONCLUSIONS

Circulating NE levels in the early postoperative period might be a useful predictor of PICs in immune-controlled UC patients who received high doses of steroids.