Evaluation of an institutional project to improve venous thromboembolism prevention

Comparison of inpatient versus post-discharge venous thromboembolic events after spinal surgery: A single institution series of 6869 consecutive patients

STUDY DESIGN

retrospective chart review.

OBJECTIVE

We aimed to determine the perioperative risk factors that lead to inpatient or post-discharge venous thromboembolism (VTE) events after spinal surgery.

SUMMARY OF BACKGROUND DATA

While many studies relate the risk factors in a post-surgical setting to the incidence of VTE, this study aims to separate these VTE into inpatient and post-discharge categories to examine timing and risk factors.

METHODS

We analyzed 6869 patients from 2009 to 2015 using Current Procedural Technology codes from a single tertiary academic institution. Patients were stratified based on occurrence and setting of VTE then controlled for perioperative characteristics with exclusion criteria being patients undergoing minor spine surgeries or secondary procedures.

RESULTS

In 170 VTE events, these factors were associated with increased risk for: Inpatient DVT only: IVC filter (OR 6.380 [3.414-11.924]), longer length of hospital stay (OR 1.083 [1.047-1.120]), a prior history of DVT (OR 3.640 [1.931-6.856]). Post-discharge DVT only: history of PE (OR 45.142 [6.785-300.351]), having a corpectomy (OR 26.670 [3.477-204.548]), and having an osteotomy (OR 18.877 [1.129-315.534]). Inpatient PE only: surgery >4 h (OR 30.820, p < 0.001), fracture (OR 6.913, p = 0.004), IVC filter (OR 3.135, p = 0.029). Post-discharge PE only: corpectomy (OR 541.271, p = 0.009), foraminotomy (OR 40.137, p = 0.013), EBL > 500cc (OR 2467.798, p = 0.002). Time to onset of VTE events was significantly longer for patients undergoing osteotomy (7.43 days) than for patients with fracture (4.28 days), which is consistent with our findings that fracture was an independent predictor of inpatient VTE, and osteotomy was an independent predictor of post-discharge VTE (p = 0.018).

CONCLUSIONS

Time-to-VTE varies between types of surgeries. Some risk factors are independently associated with VTE at all times during the 30-day postoperative period, while other factors are only associated with either inpatient or post-discharge VTE. Those patients with high-risk features for post-discharge VTE merit increased study for thromboprophylaxis management.

Quality Initiative to Improve Compliance With Perioperative Anticoagulation

PURPOSE

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in gynecologic oncology surgical patients. Many centers use neuraxial analgesia (NA), which affects the timing of prophylactic anticoagulation. In 2012, we determined that the rate of VTE in patients undergoing laparotomy with NA was higher than in those who received alternative pain control. In addition, compliance with preoperative anticoagulation guidelines was only 40%. We undertook a quality initiative (QI) project to increase compliance to 80% in NA cases and maintain 90% in non-NA cases.

METHODS

A multidisciplinary working group designed and deployed a QI intervention bundle. Compliance was defined as the receipt of a prophylactic dose of anticoagulant within 1 hour after NA or before skin incision regardless of anesthesia type. Data were abstracted from the medical record after the study period. Cases from the year before QI were used for comparison. Primary outcome was compliance and secondary outcome was the rate of VTE.

RESULTS

One hundred women were treated under the QI project and 182 historical cases (HCs) were used for comparison. Overall compliance improved (96% QI v 73% HC; P < .001). This difference was marked in cases with NA (95% QI v 40% HC; P < .001) and remained stable in non-NA cases (97% QI v 91% HC; P = .29). The overall rate of VTE, independent of anesthesia type, remained unchanged (2.1% HC v 0% QI; P = .3).

CONCLUSION

Relatively simple and inexpensive initiatives to improve routine processes within the surgical pathway are feasible and attract staff participation. Such efforts are likely to translate into greater levels of patient safety.