B45. On the risk of postoperative pulmonary thromboembolism, its recognition and treatment.

Page created on October 2, 2021. Last updated on March 21, 2024 at 19:10

Introduction

Immobilising patients during the postoperative period increases the risk for venous thromboembolism (VTE), including DVT and PE. Especially orthopaedic and traumatological surgeries require longer postoperative immobilisation. It’s important to prevent and know how to recognise this.

Recognition

For clinical features of VTE, see topic 33 of internal medicine final.

Risk stratification and prevention for non-orthopaedic surgery

To choose the proper modality of prevention, it’s important to quantify the patient’s risk for VTE. The Caprini score can be used to quantify this risk.

Based on the Caprini score, the suggested interventions are as follows:

VTE risk	Caprini score	Prophylaxis recommended
Very low	0	None
Low	1 – 2	Mechanical prevention
Moderate	3 – 4	LMWH
High	≥ 5	LMWH ± mechanical prevention

The following methods are used in prevention:

• Early and frequent ambulation/physiotherapy
• Mechanical prevention
  • Compression stockings
  • Intermittent pneumatic compression of the leg
• Pharmacological prophylaxis with LMWH

The preferred anticoagulants for pharmacological prophylaxis are dalteparin (Fragmin) 5000 IE s.c. or enoxaparin (Klexane) 40 mg s.c.

The optimal timing for initiation and termination of anticoagulant prophylaxis should be individualised. Generally, in uncomplicated cases with low bleeding risk they’re initiated 12 hours before surgery and continued until the patient becomes fully ambulatory or is discharged.

In patients at high risk for bleeding, anticoagulants are contraindicated for prevention. Patients at moderate or high risk for DVT/PE with contraindications to anticoagulants should receive non-pharmacological methods of prevention.

Risk stratification and prevention for orthopaedic surgery

To choose the proper modality of prevention, it’s important to quantify the patient’s risk for VTE. The Caprini score is generally not used for orthopaedic surgery, as it was only validated for non-orthopaedic surgery. No scoring system is used to evaluate for VTE risk in orthopaedic surgery; an individual assessment based on the patient’s risk factors is used to estimate the risk. The following are known risk factors for VTE after orthopaedic surgery:

• History of VTE
• Age > 80
• Severe comorbidity (Charlson score > 3)
• High ASA classification

The Charlson comorbidity index scores the patient’s comorbidities based on severity.

The type of surgery is also important. Major surgery (hip or knee replacement or other hip fracture treatment) is considered high-risk for VTE and in these cases pharmacological prophylaxis is usually recommended.

The following methods are used in prevention:

• Early and frequent ambulation/physiotherapy
• Mechanical prevention
  • Compression stockings
  • Intermittent pneumatic compression of the leg
• Pharmacological prophylaxis with anticoagulants

The preferred anticoagulants for pharmacological prophylaxis are dalteparin (Fragmin) 2500 – 5000 IE s.c. or enoxaparin (Klexane) 40 mg s.c. Apixaban (Eliquis), dabigatran (Pradaxa), and rivaroxaban (Xarelto) are likely equally good alternatives for orthopaedic surgery.

Type of surgery	Risk for VTE	Prophylaxis recommended
Larger hip or knee surgery	Moderate or high risk	Anticoagulant for 10 – 35 days
Larger hip or knee surgery	Low risk	Anticoagulant for 10 days
Smaller surgeries	Any risk	No anticoagulant

Treatment

For treatment of VTE, see topic 33 of internal medicine final.