The autopsy: still important in cardiac surgery

Respiratory nursing care with Angong Niuhuang pill for patients with chronic obstructive pulmonary disease following cardiac surgery

AIM

Angong Niuhuang pill (ANP) is a traditional Chinese medicine (TCM) drug widely used for treating stroke. This study aimed to investigate the effect of ANP on respiratory nursing outcomes in chronic obstructive pulmonary disease (COPD) patients following cardiac surgery.

METHODS

A total of 80 COPD patients following cardiac surgery were enrolled and randomized into the control group receiving routine postoperative nursing and ANP group additionally receiving ANP treatment for 3 days (n = 40 for both group). The frequency of back percussion, time of back percussion, amount of expectoration, arterial blood gas levels were compared between groups.

RESULTS

Compared to the control group, the ANP group had a significantly shorter daily mean time of back percussion at day 3 (p = .036) and day 7 (p = .014). The daily mean amount of expectoration was higher at day3 (p = .018) but lower at day 7 (p = .043) in the ANP group than in the control group. In addition, the ANP group had significantly higher hemoglobin saturation (SpO₂ ) and partial pressure of oxygen (PaO₂ ) but lower partial pressure of carbon dioxide (PaCO₂ ) at both day 3 and day 7 than the control group (all p < .05). Furthermore, the time of postoperative aerosol inhalations (p = .041), pulmonary infection rate (p = .025) and postoperative hospital stay (p = .036) were significantly reduced in the ANP group. The ANP group had significantly lower TCM symptom scores at day 3 and day 7 after surgery.

CONCLUSION

These results suggested that ANP treatment can effectively promote the postoperative recovery and respiratory nursing outcomes in COPD patients following cardiac surgery.

Association of Acute Venous Thromboembolism With In-Hospital Outcomes of Coronary Artery Bypass Graft Surgery

Background

While venous thromboembolism (VTE) prophylaxis is a strong recommendation after most surgeries, it is controversial in cardiac surgeries such as coronary artery bypass grafting (CABG), because of perceived low VTE incidence and increased bleeding risk. Prior studies may not have been adequately powered to study outcomes of VTE in this population. We sought to investigate the postoperative incidence and outcomes of CABG patients using a large national inpatient database.

Methods and Results

We utilized the 2013 to 2014 National Inpatient Sample to identify all patients >18 years of age who underwent CABG (without concomitant valvular procedures), and had VTE during the hospital stay. We then compared clinically relevant outcomes in patients with and without VTE. We identified 331 950 CABG procedures. Of these, 1.3% (n=4205) had VTE. Patients with VTE were more likely to be older (mean 67.2±10.4 years versus 65.2±10.4 years, P<0.001). VTE was associated with higher incidence of inpatient mortality (6.8% versus 1.7%; adjusted odds ratio 1.92 [95% CI 1.40–2.65]; P<0.001) and complications. VTE was also associated with higher cost (mean±SE $81 995±$923 versus $48 909±$55) and longer length of stay (mean±SE 17.06±0.16 days versus 8.52±0.01 days).

Conclusions

Our analysis of >330 000 CABG procedures suggests that while postoperative VTE after CABG is rare, it is associated with increased morbidity and mortality. Randomized controlled trials are needed to identify optimal strategies for VTE prophylaxis in these patients.

Acute Pulmonary Embolectomy Three Days following a Coronary Artery Bypass Graft Procedure

Pulmonary embolism is very rarely reported early after cardiac surgery, most probably due to full heparinisation during cardiopulmonary bypass. We report a 66-year-old man without thromboembolic history who presented three days after a coronary artery bypass grafting procedure with acute dyspnoea and haemodynamic instability. A CT scan confirmed paracentral bilateral pulmonary embolism requiring an urgent and successful embolectomy. Review of the literature confirms that pulmonary embolism may occur in up to 3% of post-cardiopulmonary bypass patients.

The possibility of pulmonary embolism must be taken into consideration in post-cardiopulmonary bypass patients with acute onset of chest pain and respiratory insufficiency.

Incidence of Venous Thromboembolism and Benefits and Risks of Thromboprophylaxis After Cardiac Surgery: A Systematic Review and Meta-Analysis

Background

Optimal thromboprophylaxis after cardiac surgery is uncertain. This systematic review aimed to define the incidence and risk factors for deep vein thrombosis (DVT), fatal and nonfatal pulmonary embolism (PE), and assess whether venous thromboembolism (VTE) prophylaxis was effective in reducing VTE without complications after cardiac surgery.

Methods and Results

Two reviewers independently searched and assessed the quality and outcomes of randomized, controlled trials (RCTs) and observational studies on VTE after cardiac surgery in the MEDLINE, EMBASE, and Cochrane controlled trial register (1966 to December 2014). Sixty‐eight studies provided data on VTE outcomes or complications related to thromboprophylaxis after cardiac surgery. The majority of the studies were observational studies (n=49), 16 studies were RCTs, and 3 were meta‐analyses. VTE prophylaxis was associated with a reduced risk of PE (relative risk [RR], 0.45; 95% confidence interval [CI], 0.28–0.72; P=0.0008) or symptomatic VTE (RR, 0.44; 95% CI, 0.28–0.71; P=0.0006) compared to the control without significant heterogeneity. Median incidence (interquartile range) of symptomatic DVT, PE, and fatal PE were 3.2% (0.6–8.1), 0.6% (0.3–2.9), and 0.3% (0.08–1.7), respectively. Previous history of VTE, obesity, left or right ventricular failure, and prolonged bed rest, mechanical ventilation, or use of a central venous catheter were common risk factors for VTE. Bleeding or cardiac tamponade requiring reoperation owing to pharmacological VTE prophylaxis alone, without systemic anticoagulation, was not observed.

Conclusions

Unless proven otherwise by adequately powered RCTs, initiating pharmacological VTE prophylaxis as soon as possible after cardiac surgery for patients who have no active bleeding is highly recommended.

[Cardiac surgery in underlying chronic pulmonary disease. Prognostic implications and efficient preoperative evaluation]

Cardiac surgery in patients with chronic pulmonary diseases carries a high risk of postoperative pulmonary complications (ppc) because both are known to cause ppc. Autopsy studies have revealed ppc as the main cause of mortality in approximately 5-8% of patients after cardiac surgery. Not all pulmonary diseases are high risk comorbidities in cardiac surgery: whereas chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea significantly increase the risk of ppc, a well controlled asthma does not carry an additional risk of ppc. A thorough preoperative risk stratification is crucial for risk estimation and some validated risk calculators, such as the Canet risk score exist. Surprisingly the additional value of pulmonary function testing beyond a thorough patient history and physical examination is low. No validated thresholds exist in pulmonary function testing below which cardiac surgery should be denied if clearly indicated. Perioperative strategies for risk reduction should be applied to all patients whenever possible.

[Documentation of the diagnostic quality of hospitals: evaluation of autopsy reports]

Multiple factors have affected the decline in autopsy rates. Discrepancies between clinical diagnoses and findings at autopsy are frequently used as an argument for a high autopsy rate. However, the quality of the diagnosis is independent of the autopsy rate. A long-term study covering the years 1972-2002 in the University Hospital Zurich has documented a significant reduction of diagnostic errors in internal medicine. Major diagnostic errors (class 1) declined from 16% (1972), to 9% (1982), to 7% (1992) to 2% (2002). The main reason is the availability of new diagnostic procedures. In 2010 the analysis of class 1 diagnostic errors throughout the hospital documented class 1 discrepancies in only 1%. This low number of diagnostic errors has been published in the annual quality report of the University Hospital Zurich. The documentation of this improvement in the quality report of the hospital provides the opportunity to convince clinicians, health politicians and the hospital administration to support autopsies in teaching as well as non-teaching hospitals.

Medico-legal autopsy in postoperative hemodynamic collapse following coronary artery bypass surgery

Sudden unexpected postoperative hemodynamic collapse with a high mortality develops in 1–3% of patients undergoing coronary artery bypass surgery (CABG). The contribution of surgical graft complications to this serious condition is poorly known and their demonstration at autopsy is a challenging task. Isolated CABG was performed in 8,807 patients during 1988–1999. Of the patients, 76 (0.9%) developed sudden postoperative hemodynamic collapse resulting in subsequent emergency reopening of the median sternotomy and open cardiac massage. Further emergency reoperation could be performed in 62 (82%) whereas 14 patients died prior to reoperation and a further 21 did not survive the reoperation or died a few days later. All 35 (46%) patients who did not survive were subjected to medico-legal autopsy combined with postmortem cast angiography. By combining clinical data with autopsy and angiography data, various types of graft complications were observed in 27 (36%, 1.3 per patient) of the 76 patients with hemodynamic collapse. There were no significant differences in the frequency (33 vs. 40%) or number of complicated grafts per patient (1.2 vs. 1.4) between those who survived reoperation and who did not. Autopsy detected 25 major and minor findings not diagnosed clinically. Postmortem cast angiography visualized 2 graft twists not possible to detect by autopsy dissection only. Surgical graft complications were the most frequent single cause for sudden postoperative hemodynamic collapse in CABG patients leading to a fatal outcome in almost half of the cases. Postmortem angiography improved the accuracy of autopsy diagnostics of graft complications.

Coronary artery bypass graft and/or valvular operations following prior pneumonectomy: report of four new patients and review of the literature

BACKGROUND

The reported experience is sparse for patients with prior pneumonectomy who are undergoing surgery for ischemic or valvular heart disease. Such surgery poses special technical challenges. To expand the experience with this challenging clinical intervention, we reviewed the reported patients with prior pneumonectomy who were undergoing cardiac surgery as well as the experience at the Cleveland Clinic.

METHODS

A MEDLINE search of the literature for articles published in the English language from 1966 to August 2006 was conducted using the search terms "pneumonectomy" and "cardiac surgery." We included all available individually described patients and also reviewed the Cardiovascular Information Registry at the Cleveland Clinic from 1972 to 2006.

RESULTS

A total of 19 individually described patients in 13 reports were available, 15 of which had previously been reported and 4 that were newly reported from our institution (1 of whom had undergone two operations separated by 8 years). Of the 20 operations performed in these 19 patients, coronary artery bypass grafting (CABG) alone was performed in 15 patients (75%), valve replacement or repair was performed in 4 patients (20%), and CABG with both aortic valve replacement and mitral valve repair was performed in 1 patient (5%). Most patients (13; 68%) had undergone left pneumonectomy. For these 19 patients, the postoperative mortality rate was 16%. Postoperative complications followed 10 of the operations (50%).

CONCLUSIONS

Although complications and postoperative deaths occurred more frequently than in other high-risk patient groups (eg, those with COPD undergoing cardiac surgery), this experience suggests that cardiac surgery can be undertaken with a reasonable likelihood of a favorable outcome in this challenging population, justifying the approach in appropriately selected and counseled patients.

Autopsy findings in patients on postcardiotomy extracorporeal membrane oxygenation (ECMO)

OBJECTIVES

To assess the clinical sensitivity of causes of death, concomitant diseases and postoperative complications including thromboembolic events in ECMO patients.

METHODS

Between January 2000 and December 2004 154/202 patients (76.2%) died after postcardiotomy ECMO circulatory support. Autopsy was performed in 78 (50.6%) consecutive patients. Clinical and post-mortem data were prospectively recorded and compared concerning causes of death and postoperative complications including venous and arterial thromboembolisms and significant comorbidities.

RESULTS

Mean age was 62.1+/-11.3 years, ejection fraction was 43.4+/-17.3%. 39.7% were emergency operations including acute coronary syndrome in 25.6% and preoperative cardiogenic shock in 28.2%. Successful ECMO weaning rate was 43.6%. Mean postoperative survival was 11.3 days. Premortem unknown concomitant diseases were found in 63 patients (80.8%) with clinical relevance in 9 patients (11.5%). Clinically unrecognized postoperative complications were found in 59 patients (75.6%) including acute cerebral infarction (n=7), acute bowel ischemia (1), intestinal perforation (3), pneumonia (4), venous thrombus formation (25) and systemic thromboembolic events (24). Clinically based causes of death were cardiac in 62.8%, multi-organ failure in 10.3%, cerebral in 5.1%, respiratory in 10.3%, fatal pulmonary embolism in 2.6%, technical in 5.1%, and others in 3.8%. Unexpected causes of death were found by autopsy in 22 patients (28.2%) including myocardial infarction (n=5), acute heart failure (4), fatal pulmonary embolism (2), pneumonia (2), ARDS (1), lung bleeding (1), fatal cerebrovascular event (4) and multiorgan failure (3).

CONCLUSIONS

In ECMO patients major discrepancies between clinical and post-mortem examination were found. The true incidence of thromboembolic events is highly underestimated by clinical evaluation.

Significant value of autopsy for quality management in cardiac surgery

OBJECTIVE

With recent advances in diagnostic imaging, the value of autopsy has been called into question. The aim of our study was to assess the current impact of autopsy for early postoperative quality management in cardiac surgery.

METHODS

Between 2000 and 2003, a total of 14,313 patients underwent cardiac surgery at our center. Of these, 898 patients (6.3%) died, and autopsy was performed in 468 cases (52.1%). Data from clinical and postmortem examination were prospectively analyzed regarding causes of death, postoperative complications, concomitant diseases, and surgery-associated pathologic findings.

RESULTS

Mean age was 68.7 years. Mean survival was 13.9 postoperative days. On autopsy, causes of death were cardiac in 49.8% of cases (n = 233), respiratory in 8.3% (n = 39), cerebral in 6.4% (n = 30), abdominal in 4.7% (n = 22), multiorgan failure or sepsis in 14.9% (n = 70), pulmonary embolism in 6.6% (n = 31), procedure associated in 8.3% (n = 39), and others in 0.9% (n = 4). Discrepancies between clinical and postmortem determinations of cause of death were found in 108 cases (23.1%). These were acute myocardial infarction (n = 38), low cardiac output (n = 9), respiratory (n = 8), cerebral (n = 5), abdominal (n = 7), multiorgan failure or sepsis (n = 12), pulmonary embolism (n = 18), and procedure associated (11). Clinically unrecognized postoperative complications were found in 364 cases (77.8%). Unknown concomitant diseases were found in 464 cases (99.1%), with potential therapeutic relevance in 90 cases (19.2%). In 85 cases (18.2%), autopsy examination revealed 96 premortem unrecognized surgery-associated pathologic findings.

CONCLUSION

A high overall discrepancy rate between premortem and autopsy diagnoses was recognized. Autopsy revealed clinically relevant information in a significant number of cases. Therefore autopsy remains essential for quality assessment in perioperative treatment.

[Autopsies and surgical service]

The aim of autopsy is to define the causes of a patient's death by studying the gross and microscopic visceral lesions. It is in actual decline but nevertheless the post-mortem examination remains one of the basic tools for the assessment of medical care in hospital. The aim of this paper is to finalize the present French legislation of autopsy and to show its importance in surgical practice.

Molecular mechanisms in male determination and germ cell differentiation

Sex determination and gametogenesis are key processes in human reproduction, and any defect can lead to infertility. We describe here the molecular mechanisms of male sex determination and testis formation; defects in sex determination lead to a female phenotype despite the presence of a Y chromosome, more rarely to a male phenotype with XX chromosomes, or to intersex phenotypes. Interestingly, these phenotypes are often associated with other developmental malformations. In testis, spermatozoa are produced from renewable stem cells in a complex differentiation process called spermatogenesis. Gene expression during spermatogenesis differs to a surprising degree from gene expression in somatic cells, and we discuss here mechanistic differences and their effect on the differentiation process and male fertility.

Mortality after pediatric lung transplantation: autopsies vs. clinical impression

Appreciable mortality accompanies pediatric lung and heart-lung transplantation. The objective of this investigation was to compare the clinical impression of causes of death with autopsy findings in all pediatric lung or heart lung transplant recipients who had an autopsy performed between 1985-2002 at the Children's Hospital of Pittsburgh. Medical records and autopsy findings were reviewed. Thirty recipients with autopsies had 33 transplant procedures: heart-lung (16), double lung (14), repeat lung (2), and repeat heart-lung (1). Perioperative deaths occurred in 8 children, most often precipitated by graft dysfunction. Early deaths (2 weeks-1 year) occurred in 12 children resulting from infection. Late deaths (greater than 1 year) occurred in 10 children. Bronchiolitis obliterans complicated by infection was the major cause of death in these recipients. An autopsy confirmed the clinical impression of cause of death in 29/30 and added significant supplemental information in 16 cases. Unsuspected factors contributing to death included donor lung abnormalities, concurrent infection, and cardiovascular disease. Postmortem examination remains a critical component to augment the understanding of causes of death following pediatric thoracic transplantation.

Incidence of clinically unsuspected pulmonary embolism in mechanically ventilated lung transplant recipients

BACKGROUND

The incidence of pulmonary embolism (PE) in lung transplant recipients has not been well established. The purpose of this study was to describe the incidence of clinically unsuspected PE in a cohort of lung transplant recipients requiring mechanical ventilatory support. These patients underwent surgical lung biopsy (SLBx) for progressive deterioration in the absence of a specific diagnosis.

METHODS

We retrospectively reviewed all SLBx pathology reports for mechanically ventilated lung transplant recipients with clinical deterioration, progressive radiographic abnormalities, or both at any time after transplantation. Our objective was to determine the incidence of clinically unsuspected PE in this patient population during an 11-year period.

RESULTS

Clinically unsuspected PE was identified in 8 (19.5%) of 41 mechanically ventilated lung transplant recipients after a median of 20 days (interquartile range: 16.3, 148.8 days) after transplantation. There was a tendency for clinically unsuspected PE to occur in the early postoperative period, with the majority of events (75%) occurring within 14 weeks of transplantation. Pulmonary infarction occurred in 37.5% of cases and occurred uniformly during the postoperative period. The finding of pulmonary emboli on SLBx lead to confirmatory investigations in five (62.5%) of eight patients and changed management in seven (87.5%) of eight patients.

CONCLUSIONS

A high index of suspicion and reliance on ancillary diagnostic testing may be insufficient to establish the diagnosis of postoperative pulmonary emboli. PE is an underappreciated complication contributing to respiratory failure in the early postoperative period in lung transplant recipients, warranting identification of putative risk factors and consideration for prophylaxis.

Rates of postmortem examination in Austria

BACKGROUND AND OBJECTIVE

Despite the importance of autopsies for diagnosing disease and determining cause of death, autopsy rates are decreasing in many countries. Furthermore, autopsy rates are often not distributed randomly between different regions within countries. In this study we analyzed an apparent nonrandom spatial distribution of autopsy rates in Austria for the period 1991-2000. We tested the new hypothesis that the rate of autopsies performed on people who die at home depends on the distance from the residence to the hospital or forensic institute where autopsies are performed.

METHODS

Data were extracted from the official mortality records for the years 1991-2000. Only persons who deceased in private residences were included. A logistic regression model was used.

RESULTS

Even controlling for variability in sex, age, date of death, and family status, the effect of distance significantly implied lower autopsy rates in the alpine parts of Austria.

CONCLUSIONS

This effect of distance may lead to artificially nonrandom mortality patterns in disease maps. As a consequence, the possibility of hypothesizing incorrect health risks to explain nonrandom mortality patterns increases.

Are coroners' necropsies necessary? A prospective study examining whether a "view and grant" system of death certification could be introduced into England and Wales

AIMS

To determine whether the cause of death could be accurately predicted without the need for a necropsy, and thus to consider whether a "view and grant" system of issuing a cause of death could be introduced into England and Wales.

METHOD

A one year prospective necropsy study was performed incorporating 568 deaths. Before necropsy, in each case the cause of death was predicted from the available history without examination of the body, and this cause was then compared with the cause of death found at necropsy.

RESULTS

The ability of the pathologist involved in the study to predict a cause of death before necropsy, either while in the mortuary or as a paper exercise, was shown to vary between 61% and 74% of cases. After the necropsy, the number of correct predicted causes of death ranged from 39% to 46%. Ischaemic heart disease was found to be the most common and most accurately predicted cause of death. Some natural diseases were frequently misdiagnosed, whereas certain types of unnatural disease were always identified correctly.

CONCLUSIONS

This study highlights the advantages and disadvantages of a view and grant system. Although it identifies a potential use of such a system, in some cases such as natural cardiac disease, because of the potentially high diagnostic error rate, the continuation of the present system of postmortem examination as part of the coroner's enquiry is recommended.

Clinical versus actual outcome in cardiac surgery: a post-mortem study

BACKGROUND

Clinical attribution of the cause of death can be misleading, with the only true outcome measure being post-mortem analysis. Despite this there is very little published data on post-mortems following cardiac surgery.

METHODS

Prospective consecutive post-mortem data were collected on 167 patients (84.4% of all in-hospital cardiac surgical deaths) in a single institution. Clinical diagnoses were compared with post-mortem findings.

RESULTS

The mean age at death was 69.8 with 67.6% male. The proportion undergoing coronary artery bypass graft (CABG) alone was 52.1%, valve surgery 18.6%, valve+CABG 19.2% and other procedures 10.1%. The mean time to death was 7.9 days (range 0-87). The causes of death were cardiac 67.7%, gastrointestinal 9.6%, respiratory 8.4%, haemorrhage/technical failure 4.8%, stroke (cerebrovascular accident) 3.6%, multiorgan failure 3.0%, sepsis 1.8%, malignancy 0. 6% and trauma 0.6%. Post-mortem revealed an unsuspected cause of death in 19 (11.4%). These were gastrointestinal (infarction nine, perforation two), cardiac three, adult respiratory distress syndrome two, technical two and pulmonary embolus one. In addition, an unsuspected lung cancer was found in 1 patient who died of cardiac causes. When cardiac deaths were compared with non-cardiac causes the Parsonnet score was higher 20.0 (+/-1.4) vs. 15.3 (+/-1.6), P=0. 07; and a greater proportion tended to have poor ejection fractions (34 vs. 15%), P=0.12. There was no significant difference between the groups in terms of age, sex, operation, hypertension, diabetes, creatinine and body mass.

CONCLUSIONS

Post-mortem can determine unsuspected diagnoses in a significant proportion of cases. Pre-operative risk factors do not correlate with eventual cause of death. Post-mortem still has an important role to play in cardiac surgery.

Post-mortem examination after cardiac surgery

Following a recent enquiry into surgery at a paediatric cardiac centre in England, there will be substantial changes in the way that the success and failure of surgical procedures will be monitored and investigated. Post-mortem examinations on patients dying after cardiac surgery are likely to be performed and reported in more detail. This review describes the protocol that we have developed and summarizes recent clinical and pathological studies that have increased our understanding of postoperative pathophysiology. Close attention should be paid to the history, particularly the operation note. Cardiac failure is the commonest cause of death. We believe this is a clinicopathological diagnosis and provide definitions of preoperative and perioperative cardiac failure. Haemorrhage, stroke, pulmonary emboli and infection are other important causes of death. Methods of dissection are suggested for bypass grafts and valve replacements. Two recent studies show that the post-mortem examination provides answers to most clinical questions and reveals an unexpected cause of death in 10-15% of patients. There are limitations however: an incomplete or indeterminate cause of death is found in 14-25% of patients, most commonly sudden clinically unexplained death or clinically unexplained cardiac failure soon after surgery.