The World Health Organisation Research into Global Hazards of Travel (Wright) Project found that the main factor contributing to deep venous thrombosis is being immobile, and the risk of developing a blood clot is higher when traveling for more than 4 hours. According to the Wright Study, the absolute risk of experiencing deep venous thrombosis during flights lasting over 4 hours was found to be one in 4656. For more information on this topic, you can refer to the guidance provided by the Civil Aviation Authority for medical professionals.

Acute limb ischaemia refers to a sudden reduction in blood flow to a limb, which puts the limb at risk of tissue death. This condition is most commonly caused by either a sudden blockage of a previously partially blocked artery by a blood clot or by an embolus that travels from another part of the body. Acute limb ischaemia is considered a medical emergency, and if not promptly treated with surgery to restore blood flow, it can lead to extensive tissue damage within six hours.

The classic signs of acute limb ischaemia are often described using the 6 Ps:
– Pain that is constant and persistent
– Absence of pulses in the ankle
– Pallor, cyanosis, or mottling of the skin
– Loss of power or paralysis in the affected limb
– Paraesthesia or reduced sensation, leading to numbness
– Feeling cold in the affected limb

It is important to be able to distinguish between ischaemia caused by a blood clot and ischaemia caused by an embolus. The following highlights the main differences:
Embolus Thrombus
– Onset is sudden, occurring within seconds to minutes – Onset is gradual, taking hours to days
– Ischaemia is usually severe due to the lack of collateral circulation – Ischaemia is less severe due to the presence of collateral circulation
– There is typically no history of claudication, and pulses may still be present in the other leg – There is often a history of claudication, and pulses may also be absent in the other leg
– Skin changes, such as marbling, may be visible in the feet. This can appear as a fine reticular blanching or mottling in the early stages, progressing to coarse, fixed mottling
– Skin changes are usually absent in cases of thrombus-induced ischaemia.

The NICE guidelines for suspected deep vein thrombosis (DVT) suggest considering the possibility of DVT if typical symptoms and signs are present, particularly if the person has risk factors like previous venous thromboembolism and immobility.

Typical signs and symptoms of DVT include unilateral localized pain (often throbbing) that occurs during walking or bearing weight, as well as calf swelling (or, less commonly, swelling of the entire leg). Other signs to look out for are tenderness, skin changes such as edema, redness, and warmth, and vein distension.

To rule out other potential causes for the symptoms and signs, it is important to conduct a physical examination and review the person’s general medical history.

When assessing leg and thigh swelling, it is recommended to measure the circumference of the leg 10 cm below the tibial tuberosity and compare it with the unaffected leg. A difference of more than 3 cm between the two legs increases the likelihood of DVT.

Additionally, it is important to check for edema and dilated collateral superficial veins on the affected side.

To assess the likelihood of DVT and guide further management, the two-level DVT Wells score can be used.

For more information, you can refer to the NICE Clinical Knowledge Summary on deep vein thrombosis.

Acute limb ischaemia refers to a sudden decrease in blood flow to a limb, which puts the limb at risk of tissue death. This condition is most commonly caused by either a sudden blockage of a partially blocked artery or an embolus that travels from another part of the body. It is considered a surgical emergency, as without prompt surgical intervention, the limb may suffer extensive tissue damage within six hours.

The typical signs of acute limb ischaemia are often described using the 6 Ps: constant and persistent pain, absence of pulses in the ankle, paleness or discoloration of the limb, loss of power or paralysis, reduced sensation or numbness, and a sensation of coldness. The leading cause of acute limb ischaemia is a sudden blockage of a previously narrowed artery (60% of cases). The second most common cause is an embolism, such as from a blood clot in the heart or following a heart attack. It is important to differentiate between these two causes, as the treatment and prognosis differ.

Other potential causes of acute limb ischaemia include trauma, Raynaud’s syndrome, iatrogenic injury (caused by medical procedures), popliteal aneurysm, aortic dissection, and compartment syndrome. If acute limb ischaemia is suspected, it is crucial to seek immediate assessment by a vascular surgeon.

The management of acute limb ischaemia in a hospital setting depends on factors such as the type and location of the blockage, duration of ischaemia, presence of other medical conditions, type of blood vessel affected, and the viability of the limb. Treatment options may include percutaneous catheter-directed thrombolytic therapy, surgical embolectomy, or endovascular revascularisation if the limb can still be saved. The choice between surgical and endovascular techniques will depend on various factors, including the urgency of revascularisation and the severity of sensory and motor deficits.

In cases where the limb is beyond salvage, amputation may be necessary. This is because attempting to revascularise a limb with irreversible ischaemia and extensive muscle death can lead to a condition called reperfusion syndrome, which can cause inflammation and damage to multiple organs, potentially resulting in death.

The NICE guidelines for suspected DVT state that if a person scores two points or more on the DVT Wells score, they are likely to have DVT. On the other hand, if a person scores one point or less, it is unlikely that they have DVT.

For individuals who are likely to have DVT, it is recommended to offer a proximal leg vein ultrasound scan with the results available within 4 hours if possible. However, if the ultrasound scan cannot be done within 4 hours, the following steps should be taken: a D-dimer test should be offered, followed by interim therapeutic anticoagulation. It is preferable to choose an anticoagulant that can be continued if DVT is confirmed. Additionally, a proximal leg vein ultrasound scan should be conducted with the results available within 24 hours.

For individuals who are unlikely to have DVT, it is advised to offer a D-dimer test with the results available within 4 hours. If obtaining the results within 4 hours is not possible, interim therapeutic anticoagulation should be provided while awaiting the result. If feasible, an anticoagulant that can be continued if DVT is confirmed should be chosen.

For more information, you can refer to the NICE Clinical Knowledge Summary on deep vein thrombosis.

The NICE guidelines for suspected deep vein thrombosis (DVT) suggest considering the possibility of DVT if typical symptoms and signs are present, particularly if the person has risk factors like previous venous thromboembolism and immobility.

Typical signs and symptoms of DVT include unilateral localized pain (often throbbing) that occurs during walking or bearing weight, as well as calf swelling (or, less commonly, swelling of the entire leg). Other signs to look out for are tenderness, skin changes such as edema, redness, and warmth, and vein distension.

To rule out other potential causes for the symptoms and signs, it is important to conduct a physical examination and review the person’s general medical history.

When assessing leg and thigh swelling, it is recommended to measure the circumference of the leg 10 cm below the tibial tuberosity and compare it with the unaffected leg. A difference of more than 3 cm between the two legs increases the likelihood of DVT.

Additionally, it is important to check for edema and dilated collateral superficial veins on the affected side.

To assess the likelihood of DVT and guide further management, the two-level DVT Wells score can be used.

For more information, you can refer to the NICE Clinical Knowledge Summary on deep vein thrombosis.

The current guidelines from NICE recommend that the first-line treatment for confirmed deep-vein thrombosis (DVT) or pulmonary embolus (PE) should be either apixaban or rivaroxaban, which are direct oral anticoagulants.

If neither of these options is suitable, the following alternatives should be considered:

1. LMWH (low molecular weight heparin) should be administered for at least 5 days, followed by dabigatran or edoxaban.

2. LMWH should be combined with a vitamin K antagonist (VKA), such as warfarin, for at least 5 days or until the international normalized ratio (INR) reaches at least 2.0 on 2 consecutive readings. Afterward, the VKA can be continued alone.

Acute limb ischaemia refers to a sudden reduction in blood flow to a limb, which puts the limb at risk of tissue death. This condition is most commonly caused by either a sudden blockage of a previously partially blocked artery by a blood clot or by an embolus that travels from another part of the body. Acute limb ischaemia is considered a medical emergency, and if not promptly treated with surgery to restore blood flow, it can lead to extensive tissue damage within six hours.

The classic signs of acute limb ischaemia are often described using the 6 Ps:
– Pain that is constant and persistent
– Absence of pulses in the ankle
– Pallor, cyanosis, or mottling of the skin
– Loss of power or paralysis in the affected limb
– Paraesthesia or reduced sensation, leading to numbness
– Feeling cold in the affected limb

It is important to be able to distinguish between ischaemia caused by a blood clot and ischaemia caused by an embolus. The following highlights the main differences:
Embolus Thrombus
– Onset is sudden, occurring within seconds to minutes – Onset is gradual, taking hours to days
– Ischaemia is usually severe due to the lack of collateral circulation – Ischaemia is less severe due to the presence of collateral circulation
– There is typically no history of claudication, and pulses may still be present in the other leg – There is often a history of claudication, and pulses may also be absent in the other leg
– Skin changes, such as marbling, may be visible in the feet. This can appear as a fine reticular blanching or mottling in the early stages, progressing to coarse, fixed mottling
– Skin changes are usually absent in cases of thrombus-induced ischaemia.

The NICE guidelines for suspected deep vein thrombosis (DVT) suggest considering the possibility of DVT if typical symptoms and signs are present, particularly if the person has risk factors like previous venous thromboembolism and immobility.

Typical signs and symptoms of DVT include unilateral localized pain (often throbbing) that occurs during walking or bearing weight, as well as calf swelling (or, less commonly, swelling of the entire leg). Other signs to look out for are tenderness, skin changes such as edema, redness, and warmth, and vein distension.

To rule out other potential causes for the symptoms and signs, it is important to conduct a physical examination and review the person’s general medical history.

When assessing leg and thigh swelling, it is recommended to measure the circumference of the leg 10 cm below the tibial tuberosity and compare it with the unaffected leg. A difference of more than 3 cm between the two legs increases the likelihood of DVT.

Additionally, it is important to check for edema and dilated collateral superficial veins on the affected side.

To assess the likelihood of DVT and guide further management, the two-level DVT Wells score can be used.

For more information, you can refer to the NICE Clinical Knowledge Summary on deep vein thrombosis.

The current guidelines from NICE recommend that the first-line treatment for confirmed deep-vein thrombosis (DVT) or pulmonary embolism (PE) should be either apixaban or rivaroxaban, which are direct oral anticoagulants.

If neither of these options is suitable, the following alternatives should be considered:

1. LMWH (low molecular weight heparin) should be administered for at least 5 days, followed by dabigatran or edoxaban.

2. LMWH should be combined with a vitamin K antagonist (VKA), such as warfarin, for at least 5 days or until the international normalized ratio (INR) reaches at least 2.0 on 2 consecutive readings. Afterward, the VKA can be continued alone.