Age- and sex-specific incidence, risk, and latency period of a perioperative acute thromboembolism syndrome (PATS)

Restrictive blood transfusion and 1-year mortality in patients undergoing open abdominal surgery: A retrospective propensity score-matched cohort study

BACKGROUND

The importance of patient blood management is increasingly recognized in surgery patients. This study aimed to examine the effect of perioperative restrictive blood transfusion on 1-year mortality and blood transfusion rate in open abdominal surgery.

METHODS

We retrospectively studied 452 consecutive patients who underwent open abdominal surgery before (liberal group: 233 patients) and after (restrictive group: 219 patients) implementing intraoperative restrictive transfusion of red blood cell. The trigger levels of hemoglobin were less than 9-10 g/dL in the liberal group and less than 7-8 g/dL in the restrictive group. All-cause mortality at 1-year as the primary outcome and the transfusion rate of any allogeneic blood products as secondary outcome were compared between the liberal group and the restrictive group by the propensity-score matching.

RESULTS

Among a total of 452 patients (69 ± 11 yr., 70.5 % men), overall mortality at 1 year was 8.4 % and the proportion of patients who received any allogeneic blood products was 19.6 %. Compared with 155 propensity-score matched patients of the liberal group, 155 matched patients of the restrictive group had significantly lower 1-year mortality (4 [2.5 %] versus 18 [11.6 %], p = 0.003, percent absolute risk reduction [%ARR]; 9.0, 95 % confidential interval [CI], 3.1-14.7) and had significantly lower proportion of patients who received any allogeneic blood products (21 [13.5 %] versus 41 [26.4 %], p = 0.006, %ARR; 12.9, 95 % CI, 3.9-21.5).

CONCLUSIONS

The results of this study indicate that intraoperative restrictive blood transfusion reduces 1-year mortality and the transfusion rate of allogeneic blood products.

Crucial considerations: Sex differences in the epidemiology, diagnosis, treatment, and outcomes of acute pulmonary embolism in non-pregnant adult patients

Acute pulmonary embolism (PE) affects over 600,000 Americans per year and is a common diagnostic consideration among emergency department patients. Although there are well-documented differences in the diagnosis, treatment, and outcomes of cardiovascular conditions, such as ischemic heart disease and stroke, the influence of sex and gender on PE remains poorly understood. The overall age-adjusted incidence of PE is similar in women and men, but women have higher relative rates of PE during early and mid-adulthood (ages 20-40 years); whereas, men have higher rates of PE after age 60 years. Women are tested for PE at far higher rates than men, yet women who undergo computed tomography pulmonary angiography are ultimately diagnosed with PE 35%-55% less often than men. Among those diagnosed with PE, women are more likely to have severe clinical features, such as hypotension and signs of right ventricular dysfunction. When controlled for PE severity, women are less likely to receive reperfusion therapies, such as thrombolysis. Finally, women have more bleeding complications for all types of anticoagulation. Further investigation of possible sex-specific diagnostic and treatment algorithms is necessary in order to more accurately detect and treat acute PE in non-pregnant adults.

Sudden Death Due to Bilateral Pulmonary Thromboembolism Following Laparoscopic Cholecystectomy

Cases of sudden death due to pulmonary thromboembolism (PTE) following laparoscopic surgery are very rare. The risk factors for PTE include sex, operation duration, age, obesity, and underlying diseases. The development of thromboprophylaxis according to specific risk factors has contributed to the decrease in postoperative mortality. Here, we describe the case of a 50-year-old patient with sudden death due to PTE at 24 hours after laparoscopic cholecystectomy. The origin of the thrombi were bilateral deep vein thromboses in both the lower extremities. No severe risk factors for PTE were detected in the patient, and pneumatic compression devices were used during the surgery for thromboprophylaxis. We believe that the accumulation of minor risk factors may have contributed to the onset of PTE. Hence, a more cautious assessment of the risk factors for PTE prior to surgery is required in such cases.

Retrospective comparison of thromboelastography results to postmortem evidence of thrombosis in critically ill dogs: 39 cases (2005-2010)

OBJECTIVE

To determine whether there is an association between thromboelastography (TEG) data and necropsy evidence of thrombosis in a cohort of critically ill dogs.

DESIGN

Retrospective study (2005-2010).

SETTING

University teaching hospital.

ANIMALS

Thirty-nine client-owned critically ill dogs for which TEG was performed within 7 days of complete necropsy.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Thrombi were found in 26 (67%) dogs. Spayed females (n = 20) were significantly more likely to have thrombosis (P = 0.0127). No significant association was found between presence of thrombosis and any TEG parameter, the calculated coagulation index, results of coagulation testing, type of vascular access, or clinical diagnosis. D-dimers were significantly higher in dogs with thrombosis (P = 0.0207) and a weak positive correlation was found between D-dimer value and number of sites of thrombosis (ρ = 0.18, P = 0.0045). Dogs with WBC > 16 × 10(3) /μL were more likely to have thrombosis compared to others (odds ratio 5.56, 95% confidence interval 1.2-25.7, P = 0.025).

CONCLUSIONS

This study found no association between any TEG parameter and the presence of thrombosis on postmortem examination.

Venous thromboembolic disease in colorectal patients

Venous thromboembolic disease, which includes deep vein thromboses as well as pulmonary emboli, can be a significant complication in the postoperative patient. In particular, colorectal patients often carry a higher risk for venous thromboembolism when compared with patients undergoing other operative procedures. Features unique to colorectal patients are the high incidence of inflammatory bowel disease or malignancy. Typically, these patients will undergo lengthy pelvic procedures, which also contribute to a cumulative risk of venous thrombosis. It is critical that all patients and the proposed operative procedure are appropriately risk stratified. Risk stratification allows for easier implementation of an appropriate prophylactic strategy. There are a wide range of safe and effective mechanical and pharmacologic measures available. The authors provide very specific recommendations, but note that clinical judgment plays a significant role.

Age and comorbidity as risk factors for vocal cord paralysis associated with tracheal intubation

BACKGROUND

Vocal cord paralysis after tracheal intubation may be attributed to ageing and comorbidity. However, the relationship between patient characteristics and the risk of vocal cord paralysis is unknown.

METHODS

We prospectively analysed data representing 31 241 consecutive surgery patients who underwent tracheal intubation to determine whether duration of intubation, age, sex, and cardiovascular, cerebrovascular, and metabolic diseases were risk factors for vocal cord paralysis associated with intubation. Patients with vocal cord paralysis from any other causes were excluded.

RESULTS

Twenty-four (0.077%) suffered vocal cord paralysis (left, 16 patients; right, 8 patients). The risk was increased when intubation lasted 3-6 h (odds ratio, 2.0; 95% confidence interval, 1.1-5.6; P = 0.002) or 6 h or more (odds ratio, 14.5; 95% confidence interval, 5.2-40.9; P < 0.0001). The risk was increased in patients aged 50-69 (odds ratio, 3.6; 95% confidence interval, 1.2-11.1; P = 0.02) and 70 yr or above (odds ratio, 3.9; 95% confidence interval, 1.2-12.8; P = 0.02). The risk was increased with diabetes mellitus (odds ratio, 2.5; 95% confidence interval, 1.1-7.3; P = 0.03) and hypertension (odds ratio, 2.1; 95% confidence interval, 1.1-6.0; P = 0.03).

CONCLUSIONS

The risk of vocal cord paralysis was increased three-fold in patients aged 50 or above, two-fold in patients intubated 3-6 h, 15-fold in patients intubated 6 h or more, and two-fold in patients with a history of diabetes mellitus or hypertension. Our results are informative for informed consent, patient counselling, and intubation decision-making.

Incidence of clinical pulmonary embolism after laparoscopic surgery

Background

This study aimed to determine the incidence of pulmonary embolism (PE) following laparoscopic surgery and its potential risk factors.

Methods

Data concerning 44 453 patients from 114 surgical institutions were collected by the Swiss Association of Laparoscopic and Thoracoscopic Surgery. The incidence of postoperative PE despite thromboprophylaxis was evaluated and potential risk factors were assessed singly, and then in a consecutive stepwise logistic multiple regression analysis.

Results

Among 44 453 patients assessed, 55·8 per cent were female and 44·2 per cent were male. Interventions included cholecystectomy (52·8 per cent), hernia repair (17·7 per cent), appendicectomy (12·4 per cent), colonic surgery (4·6 per cent) and oesophageal surgery (5·5 per cent). Postoperative PE occurred in 86 patients (0·2 per cent), and the incidence tended to decrease during this study (P = 0·016). A total of 149 patients died (0·3 per cent) of which nine (6·0 per cent) were due to PE. Significant predictive risk factors were female sex (P &lt; 0·001), age (P &lt; 0·001), weight above 90 kg (P &lt; 0·001), emergency procedure (P &lt; 0·001) and operating time exceeding 150 min (P &lt; 0·001).

Conclusion

The low incidence of PE after laparoscopy, with a further decrease over the past decade, suggests a tendency towards improved perioperative thromboembolic risk management.

A Double-Blind, Placebo-Controlled Trial of Epsilon-Aminocaproic Acid for Reducing Blood Loss in Coronary Artery Bypass Grafting Surgery

BACKGROUND

Epsilon-aminocaproic acid is a plasmin inhibitor that potentially reduces perioperative bleeding when administered prophylactically to cardiac surgery patients. To evaluate the efficacy of epsilon-aminocaproic acid, a prospective placebo-controlled trial was conducted in patients undergoing primary coronary artery bypass grafting surgery.

STUDY DESIGN

One hundred patients were randomly assigned to receive either epsilon-aminocaproic acid (100 mg/kg before skin incision followed by 1 g/hour continuous infusion until chest closure, 10 g in cardiopulmonary bypass circuit) or placebo, and the efficacy of epsilon-aminocaproic acid was evaluated by the reduction in postoperative thoracic-drainage volume and in donor-blood transfusion up to postoperative day 12.

RESULTS

Postoperative thoracic-drainage volume was significantly lower in the epsilon-aminocaproic acid group compared with the placebo group (epsilon-aminocaproic acid, 649 +/- 261 mL; versus placebo, 940 +/- 626 mL; p=0.003). There were no significant differences between the epsilon-aminocaproic acid and placebo groups in the percentage of patients requiring donor red blood cell transfusions (epsilon-aminocaproic acid, 24%; versus placebo, 18%; p=0.62) or in the number of units of donor red blood cells transfused (epsilon-aminocaproic acid, 2.2 +/- 0.8 U; versus placebo, 1.9 +/- 0.8 U; p=0.29). Epsilon-aminocaproic acid did not reduce the risk of donor red blood cell transfusions compared with placebo (odds ratio: 1.2, 95% confidence interval; 0.4 to 3.2, p=0.63).

CONCLUSIONS

Prophylactic administration of epsilon-aminocaproic acid reduces postoperative thoracic-drainage volume by 30%, but it may not be potent enough to reduce the requirement and the risk for donor blood transfusion in cardiac surgery patients. This information is useful for deciding on a therapy for hemostasis in cardiac surgery.

Hyperhomocysteinemia and arteriovenous fistula thrombosis in hemodialysis patients

BACKGROUND

To date, the relationship between vascular access (VA) failure and plasma total homocysteine level has been investigated only in mixed dialysis populations (ie, patients with a native arteriovenous [AV] fistula or arterial graft), whereas almost no data exist for hemodialysis patients with a native AV fistula.

METHODS

In this prospective cohort study, we examined the relationship between plasma total homocysteine level and the methylenetetrahydrofolate reductase (MTHFR) gene and VA-related incident morbidity in a cohort of 205 hemodialysis patients, all with a native AV fistula.

RESULTS

During follow-up, 78 patients experienced 1 or more VA thrombotic episodes. Patients with incident VA thrombosis had a significantly greater plasma total homocysteine level compared with patients without this event (P = 0.046). In Kaplan-Meier survival analysis, the hazard ratio for VA thrombosis increased in parallel with homocysteine level, such that patients in the third homocysteine level tertile had a relative risk for this outcome 1.72 times (95% CI, 1.21 to 2.24) greater than in those in the first tertile (log-rank test, 6.81; P = 0.009). In a multiple Cox regression model, plasma total homocysteine level was confirmed to be an independent predictor of AV fistula outcome. Plasma total homocysteine level was significantly greater (P < 0.001) in patients with the TT genotype of the MTHFR gene than in those with the CT or CC genotype.

CONCLUSION

VA thrombosis in dialysis patients is associated with hyperhomocysteinemia. Intervention studies are needed to clarify whether decreasing plasma homocysteine concentrations may prevent VA failure in hemodialysis patients.

Age as a risk factor for venous thromboembolism after major surgery

PURPOSE OF REVIEW

Postoperative deep venous thrombosis and pulmonary embolism are serious and potentially life-threatening complications that frequently occur after major surgery. Most guidelines for thromboprophylaxis use advancing age as a key component to estimate thromboembolic risk. The reported effect of age on postoperative venous thromboembolism varies widely, making it unclear whether age alone is a significant risk factor. This article reviews the recent literature on the effect of age on the incidence of postoperative venous thromboembolism.

RECENT FINDINGS

Between 2003 and 2005, several cohort studies assessed the risk factors for postoperative venous thromboembolism, showing a variable effect of age on its incidence in the 2- to 3-month period after major surgery. Studies also revealed a significant difference in the effect of age on the incidence of venous thromboembolism depending on the type of surgery. Obesity, postoperative immobilization, the use of thromboprophylaxis, the nature of the surgery, and underlying comorbid conditions such as heart failure seem to have a greater influence on the risk of venous thromboembolism than does age.

SUMMARY

The variation in the effect of age on postoperative venous thromboembolism likely depends on whether or not other comorbid conditions or age-related changes in functional status are considered as risk factors. When these other risk factors are taken into account, the effect of advanced age decreases. More research is needed to develop validated venous thromboembolism risk-prediction tools for specific types of surgery. By use of this information, the intensity and duration of postoperative thromboprophylaxis can be tailored to the level of risk, not just age alone.