Outcome and survival analysis of intestinal ischaemia following cardiac surgery

Gastrointestinal complications after cardiac surgery

Gastrointestinal complications after cardiac surgery are relatively rare entities but carry a high mortality. We identified over 70 articles written since 2010 using the PubMed database. We included 40 in our review. The most common complications include paralytic ileus, gastrointestinal bleeding, and bowel ischemia. Patients who undergo cardiac procedures are at risk for poor perfusion of the gastrointestinal tract and, thus, at risk for resulting complications. Risk factors for these complications include peri-operative use of vasopressors, prolonged operative time, and the time of cardiopulmonary bypass. Presentation of gastrointestinal complications tends to differ as patients after open heart surgery can remain intubated, and exams can be limited. Early recognition and aggressive therapy are paramount. We aim to provide a review that will help the reader get familiar with the most common gastrointestinal complications that can negatively affect outcomes after cardiac surgery.

Short-Term Outcomes and Risk Factors of In-Hospital Mortality in Patients Suffering Acute Mesenteric Ischemia after Cardiac Surgery: Role of Opioids and Lactic Acid

Acute mesenteric ischemia (AMI) is associated with poor clinical results after cardiac surgery. The aim of this study was to analyse the influence of AMI on short-term outcomes and all relevant risk factors of in-hospital mortality after cardiac surgery. Moreover, we aimed to investigate the role of opioids and lactic acid in the detection and prevention of AMI. Between August 2011 and September 2015, 176 consecutive patients with gastrointestinal complications after undergoing open-heart surgery were identified and included in this study. All patients were divided into two groups: AMI group (n = 39) and non-AMI group (n = 137). In terms of comorbidities, the groups were fairly equal and showed no significant differences. Dialysis was significantly higher (p < 0.001) in patients that suffered from AMI. Moreover, gastro-intestinal symptoms such as muscular defense (p = 0.004) and the laparotomy rate (p < 0.001) were significantly higher in the AMI group. Likewise, in-hospital mortality (p < 0.001) was significantly higher in patients with detected AMI. Univariate (p < 0.001) and multivariate analysis (p = 0.025) of both groups revealed that lactic acid value >2 mmol/L and present treatment with opioids are independent combined predictors of mesenteric ischemia in patients after undergoing cardiac surgery. Moreover, multivariate analysis showed peripheral vascular disease (p = 0.004), dialysis (p = 0.010), and septic shock (p = 0.003) as relevant predictors of in-hospital mortality. Prolonged analgetic treatment with opioids and sudden increase of lactic acid levels are independent combined predictors of mesenteric ischemia in patients after undergoing cardiac surgery. Furthermore, peripheral vascular disease, dialysis, and septic shock are relevant predictors for in-hospital mortality.

Predicting outcomes of mesenteric ischemia postcardiac surgery: A systematic review

OBJECTIVE

This systematic review aims to identify predictors of outcomes of mesenteric ischemia in patients following cardiac surgery.

METHODS

A comprehensive literature search was done on EMBASE, PubMed, Ovid MEDLINE, and SCOPUS using keywords relating to bowel ischemia and cardiac surgery. Database search results were screened by at least two authors and 32 articles were selected for inclusion in this review.

RESULTS

Data on 1907 patients were analyzed. The mean age was 70.0 ± 2.99 years and the prevalence of bowel ischemia was 1.74%. Advanced age was a significant risk factor. 63.16% of patients reported were men, and 58.4% of patients died in hospital. There was heterogeneity in the reported significance of the following preoperative risk factors: hypertension, smoking status, type 2 diabetes mellitus, end-stage renal disease, preoperative left ventricular ejection fraction <35%. Cardiopulmonary bypass (CPB) time, preoperative/operative intra-aortic balloon pump (IABP) support, and inotrope usage were significantly associated with the development of mesenteric ischemia; however, other intraoperative factors including the type of cardiac surgery and duration of aortic cross-clamping had varying levels of reported significance. There were discrepancies in the reported significance of leukocytosis and metabolic acidosis (pH <7.3) as postoperative markers. Postoperative vasopressor use, prolonged ventilation time, and elevation in lactate, transaminases, creatinine, and intestinal fatty acid-binding protein (IFABP) levels were found to be strongly associated with bowel ischemia.

CONCLUSION

This systematic review found the strongest associations of mesenteric ischemia postcardiac surgery to be advanced age, CPB time, rise in lactate, transaminases, creatinine, and IFABP. IABP support, vasopressor, and inotrope use as well as prolonged ventilation were strongly linked too.

Risk Factors Associated with In-Hospital Mortality for Patients with Acute Abdomen After Cardiac Surgery

OBJECTIVES

Management of acute abdomen (AA) differs due to the heterogeneity of underlying pathophysiology. Complications of AA and its overall outcome after cardiac surgery are known to be associated with poor results. The aim of this retrospective analysis was to evaluate risk factors for AA in patients undergoing cardiac surgery.

METHODS

Between December 2011 and December 2014, a total of 131 patients with AA after cardiac surgery were identified and retrospectively analyzed using our institutional database. Statistical analysis of risk factors concerning in-hospital mortality of mentioned patient cohort was performed using IBM SPSS Statistics.

RESULTS

Overall in-hospital mortality was 54.2% (71/131). Analyzing in-hospital non-survivors (NS) versus in-hospital survivors (S) peripheral artery disease (28.2% vs. 11.7%; p = 0.03), the need for assist device therapy (33.8% vs. 16.7%; p = 0.03) and the requirement of hemodialysis (67.6% vs. 23.3%; p < 0.01) were significantly higher in NS. Furthermore, lactic acid values at onset of symptoms were shown to be significantly higher in NS (5.7 ± 5.7 mmol/L vs. 2.8 ± 2.9 mmol/L; p < 0.01). Assured diagnosis of mesenterial ischemia was strongly associated with worse outcome (odds ratio 10.800, 95% confidence interval 2.003-58.224; p = 0.006).

CONCLUSION

In conclusion, in critically ill patients after performed cardiac surgery peripheral vascular disease, need for supportive hemodynamic assist device systems and occurrence of renal failure are risk factors associated with worsen outcome. Additionally, rise of lactic acid could potentially be associated with onset of intestinal malperfusion and should be taken into account in therapeutic decisions preventing fatal mesenterial ischemia.

Serum markers for early detection of patients with mesenteric ischemia after cardiac surgery

Objective

Mesenteric ischemia (MESI) is a rare but often fatal complication in patients after cardiac surgery. Non-specific clinical symptoms and lack of specific laboratory parameters complicate the diagnosis. We evaluated potential serum markers for MESI in cardiac surgery patients.

Methods

Between March and October 2012, serial serum samples of 567 elective cardiac surgery patients were collected 1, 24, and 48 h after the operation, and concentrations of potential markers for MESI [α-glutathione-S-transferase (αGST), intestinal fatty-acid-binding protein (iFABP), and D-lactate] were measured retrospectively. In patients requiring laparotomy, blood samples obtained 72, 48, 24, and 12 h before the laparotomy were additionally measured and compared to all other patients (control group).

Results

Laparotomy was performed in 18 patients at 11±7 days after cardiac surgery. MESI was found in 9/18 patients. Already 1 h after cardiac surgery, the serum concentrations of D-lactate (37±18 vs. 25±20 nmol/mL, p<0.01) and αGST (82±126 vs. 727±1382 μg/L, p<0.01) in patients undergoing laparotomy were increased compared to the control group. Between patients with and without MESI, differences were only found for iFABP 24 h after cardiac surgery (1.1±0.4 vs. 2.9±0.6 ng/mL, p=0.04) and up to 72 h before laparotomy (0.56±0.72 vs. 2.51±1.96 ng/mL, p=0.01).

Conclusions

D-lactate and αGST were early markers for gastrointestinal complications after cardiac surgery. Before laparotomy, lowered iFABP levels indicated MESI. Routinely used, these markers can help identify patients with gastrointestinal complications after cardiac surgery early, and might be useful for the evaluation of new therapeutic or preventive strategies.

Acute Mesenteric Ischemia Among Postcardiac Surgery Patients Presenting with Multiple Organ Failure

BACKGROUND

Acute mesenteric ischemia (AMI) is a rare but severe complication after cardiac surgery. However, AMI is likely to be more frequent in the subgroup of patients presenting with multiple organ failure after a cardiac surgery. The primary objective of this study was to identify AMI risk factors among patients requiring intensive care unit (ICU) admission after cardiac surgery.

METHODS

Retrospective observational study of all the patients requiring admission to two ICUs in a large university hospital after a cardiac surgery procedure. AMI confirmation was based on abdominal computed tomography scan, digestive endoscopy, laparotomy, or postmortem examination. Univariate and multivariate analyses were done to compare pre- and in-ICU characteristics between patients with or without AMI.

RESULTS

Between 2007 and 2013, a cardiac surgery was performed in 4,948 patients, of whom 320 patients (6%) required ICU admission for multiple organ failure. AMI was confirmed in 10% of the patients admitted to the ICU for multiple organ failure (33/320). The prognosis of these patients was extremely poor with 28- and 90-day mortality rates of 64% and 83%, respectively. Nonocclusive mesenteric ischemia (NOMI) was the main mechanism involved in 83% of the patients. Coronary artery bypass graft, need for blood transfusion during cardiopulmonary bypass, aspartate aminotransferase at least 100 UI/L, and Simplified Acute Physiology Score II at least 50 at ICU admission were independently associated with AMI. An AMI risk score based upon these four risk factors was able to identify three classes of risk: low risk (<1%), intermediate risk (9%), and high risk (29%).

CONCLUSION

AMI is a frequent condition among patients presenting with multiple organ failure after cardiac surgery, occurring in 10% of them. The prognosis of AMI is extremely poor. The main mechanism of AMI is NOMI, occurring in approximately 80% of patients. Further progress should be performed on prevention and earlier diagnosis.

Non-occlusive mesenteric ischaemia in out of hospital cardiac arrest survivors

BACKGROUND AND AIM OF THE STUDY

Non-occlusive mesenteric ischaemia (NOMI) is characterised by hypoperfusion of the intestines without evidence of mechanical obstruction, potentially leading to extensive ischaemia and necrosis. Low cardiac output appears to be a major risk factor. Cardiopulmonary resuscitation aims at restoring blood flow after cardiac arrest. However, post restoration of spontaneous circulation, myocardial stunning limits immediate recovery of sufficient cardiac function. Since after successful cardiopulmonary resuscitation patients are often ventilated and sedated, NOMI might be underdiagnosed and potentially life-saving treatment delayed.

MATERIAL AND METHODS

A prospectively maintained multi-purpose cohort of out of hospital cardiac arrest survivors, who had successful restoration of spontaneous circulation, was used for this retrospective database analysis. Patients' charts were screened for clinical, radiological or pathological evidence of NOMI and clinical data were collected.

RESULTS

Between 2000 and 2014, 1780 patients who were successfully resuscitated after out of hospital cardiac arrest were screened for NOMI. Twelve patients (0.68 %) suffered from NOMI and six of those died (50 %). Patients suffering from NOMI tended to have a longer duration until restoration of spontaneous circulation (27 vs. 20 min, p=0.128) and had significantly higher lactate (14 mmol/l vs. 8 mmol/l, p=0.002) and base deficit levels at admission (-17 vs. -10, p=0.012). Median leukocyte counts in NOMI patients peaked at the day of diagnosis.

CONCLUSION

NOMI is a rare but life-threatening and potentially curable complication following successful cardiopulmonary resuscitation. Lactate and base deficit at admission could help to identify patients at risk for developing NOMI who might benefit from increased clinical attention.

Acute bowel ischemia after heart operations

Acute bowel ischemia is a perioperative complication that is frequently unrecognized as a cause of death after cardiac surgical procedures, with an in-hospital mortality of 50% to 100%. In recent years, controversy regarding the most appropriate approach to resolve clinical or laboratory suspicion and the limited therapeutic options have led to very little improvement in patient prognosis. This article reviews the related literature examining the actual prevalence, pathophysiologic mechanisms, predisposing factors, diagnostic tests, and therapeutic approaches providing a glance at new promising tools in diagnostic workup.

Virchow’s triad and intestinal ischemia post cardiac surgery

Background

Intestinal ischemia is associated with a very high mortality rate. We combined the principles of Virchow’s triad to produce preoperative and postoperative models for the development of intestinal ischemia.

Methods

A single institutional study was undertaken involving 18,325 consecutive patients from April 1997 to March 2012. Univariate and multivariate analysis was performed.

Results

Mortality was 87% in 91 patients who developed bowel ischemia. Multivariate logistic regression demonstrated that age, peripheral vascular disease, intraaortic balloon pump support, female sex, and preexisting renal failure were significant determinates of intestinal ischemia preoperatively. Logistic regression demonstrated that age, peripheral vascular disease, creatine kinase-MB level, reoperation for bleeding, and blood product usage were significant determinates of intestinal ischemia postoperatively.

Conclusions

Potentially remedial causes of intestinal ischemia include blood product usage, reoperation for bleeding, and creatine kinase-MB release. Age, female sex, peripheral vascular disease, intraaortic balloon pump usage, and preexisting renal failure are fixed risk factors. Despite the continuing trend of reduced blood product usage in the field of cardiac surgery, the increase in patients’ risk factors will mean that incidences of intestinal ischemia may increase in the future.

Acute mesenteric ischemia after cardiac surgery: an analysis of 52 patients

OBJECTIVE

Acute mesenteric ischemia (AMI) is a rare but serious complication after cardiac surgery. The aim of this retrospective study was to evaluate the incidence, outcome, and perioperative risk factors of AMI in the patients undergoing elective cardiac surgery.

METHODS

From January 2005 to May 2013, all patients who underwent cardiac surgery were screened for participation, and patients with registered gastrointestinal complications were retrospectively reviewed. Univariate analyses were performed.

RESULTS

The study included 6013 patients, of which 52 (0.86%) patients suffered from AMI, 35 (67%) of whom died. The control group (150 patients) was randomly chosen from among cases undergoing cardiopulmonary bypass (CPB). Preoperative parameters including age (P = 0.03), renal insufficiency (P = 0.004), peripheral vascular disease (P = 0.04), preoperative inotropic support (P < 0.001), poor left ventricular ejection fraction (P = 0.002), cardiogenic shock (P = 0.003), and preoperative intra-aortic balloon pump (IABP) support (P = 0.05) revealed significantly higher levels in the AMI group. Among intra- and postoperative parameters, CPB time (P < 0.001), dialysis (P = 0.04), inotropic support (P = 0.007), prolonged ventilator time (P < 0.001), and IABP support (P = 0.007) appeared significantly higher in the AMI group than the control group.

CONCLUSIONS

Prompt diagnosis and early treatment should be initiated as early as possible in any patient suspected of AMI, leading to dramatic reduction in the mortality rate.

Intestinal ischemia after cardiac surgery: analysis of a large registry

Background

Intestinal ischemia after cardiac surgery is a rare but severe complication with a high mortality. Early surgery can be lifesaving. The aim was to analyze the incidence, outcome, and risk factors for these patients.

Methods

A prospectively collected database with patients who underwent 18,879 cardiac surgical procedures between 1996 and 2011 was investigated. All patients with registered gastrointestinal complications were retrospectively reviewed. Univariate and multivariate analyses were performed to compare patients with and without intestinal ischemia.

Results

Seventeen patients suffered from intestinal ischemia (0.09%), 10 of whom (59%) died. By investigating preoperative parameters independent risk factors were steroids, peripheral vascular disease, cardiogenic shock, and New York Heart Association class 4. When including pre-, per-, and postoperative parameters, only postoperative ones were significant, including elevated creatinine (> 200 μmol/L), prolonged ventilator time, need for intra-aortic balloon pump, and cerebrovascular insult (CVI). The gastrointestinal complications score (GICS) showed a ROC area of 0.87. This was superior compared with EuroSCORE (0.74), to predict intestinal ischemia.

Conclusions

Intestinal ischemia after cardiac surgery is more common in patients with a poor cardiac state, but the use of steroids, peripheral vascular disease, postoperative kidney failure, and CVI were also predictive. GICS score, developed for all GI complications after cardiac surgery, is also of value in predicting this particular complication. The risk factors presented can be used as an aid in the diagnosis of these patients.

Gastrointestinal complications after cardiac surgery: 10-year experience of a single Australian centre

BACKGROUND

Gastrointestinal (GI) complications after cardiac surgery are uncommon, but are associated with high morbidity and mortality as well as significant hospital resource utilization.

METHODS

We analysed a prospectively collected database containing all adult cardiac surgery procedures performed from July 2001 to March 2011 at Monash Medical Centre and Jessie McPherson Private Hospital. Patients with post-operative GI complications were compared to patients without GI complications who were operated in the same period.

RESULTS

The incidence of GI complications was 1.1% (61 out of 5382 patients) with an overall 30-day mortality of 33% (versus 3% in the non-GI complication group). The most common complications were GI bleeding, gastroenteritis and bowel ischaemia. Patients who had GI complications were significantly older, had higher incidence of renal impairment, chronic lung disease and anticoagulation therapy and were more likely to be in cardiogenic shock. Emergency procedures, combined coronary artery bypass grafting and valve surgery and aortic dissection cases were more common in the GI complication group. The GI complication group also had higher incidence of return to theatre, renal failure, stroke, septicaemia and multi-organ failure.

CONCLUSIONS

GI complications after cardiac surgery remain an uncommon but dreadful complication associated with high mortality. Our findings should prompt a high degree of clinical vigilance in order to make an early diagnosis especially in high risk patients. Further studies aiming to identify independent predictors for GI complications after cardiac surgery are warranted.