Rajagiri Tourniquet in Total knee arthroplasty.pptx

The nuances of tourniquet use with an emphasis on Total knee arthroplasty

1. THE PNEUMATIC TOURNIQUET Libin Thomas Manathara/ Rajagiri 2024

2. INTRODUCTION The pneumatic tourniquet (PT), commonly used in knee surgery, provides a bloodless operative field for better cement implantation, improves surgical visualization of the anatomic structure, and reduces operative time However, numerous known disadvantages exist The first recorded use of a tourniquet was by a Roman surgeon in the second century AD

3. INTRODUCTION In 1817, French surgeon Jean-Louis Petit described a device for hemostasis, which he named the “tourniquet.”

4. INTRODUCTION Meta analysis results PT in TKA, minor complications were more common in the PT group TKA without PT was superior to TKA with PT in terms of thromboembolic events and other related complications

5. MECHANICAL EFFECTS ISCHEMIA REPERFUSION EFFECTS SYSTEMIC EFFECTS

6. MECHANICAL EFFECTS Limb Exsanguination Pressure Under the Pneumatic Tourniquet The Mass of Tissue Under the Pneumatic Tourniquet Tissue Injury Skin Muscle Nerves Vessels

7. Limb Exsanguination Limb exsanguination is usually accomplished by mechanical means Esmarch bandage, Rhys-Davies exsanguinator increase the risk of disseminating a tumor or infection or dislodging a thrombus from a deep venous thrombosis (DVT)

8. Limb Exsanguination Exsanguination of the limb by elevation alone is a slightly less effective, but safe and easy procedure It also permits better visualization of superficial vessels To achieve maximum exsanguination, it is recommended to elevate the arm at 90 degrees for 5 minutes and elevate the leg at 45 degrees for 5 minutes, without arterial compression, while the limb is being prepped and draped If the PT is effective in occluding the extraosseous blood supply, some intraosseous blood supply is retained, which can make it difficult to obtain a bloodless field

9. MECHANICAL EFFECTS Limb Exsanguination Pressure Under the Pneumatic Tourniquet The Mass of Tissue Under the Pneumatic Tourniquet Tissue Injury Skin Muscle Nerves Vessels

10. Pressure Under the Pneumatic Tourniquet Skin, muscles, nerves, and vessels may be damaged by the mechanical pressure of the tourniquet

11. Pressure Under the Pneumatic Tourniquet Instead of using an arbitrary pressure (350 mm Hg for the lower extremity and 250 to 300 mm Hg for the upper extremity), the minimal arterial occlusion pressure (AOP) must be determined before tourniquet application to minimize tissue injury The AOP depends on the size of the tourniquet used and is determined by Graham’s formula

12. Pressure Under the Pneumatic Tourniquet The tourniquet pressure is set at AOP plus 50 to 75 mm Hg Using this formula, the PT pressure can be decreased by 20% to 40% in adults and by more than 50% for children, compared to the arbitrary pressure generally used The tourniquet pressure must be adjusted during surgery relative to blood pressure A new device was introduced that synchronizes the noninvasive blood pressure with the PT pressure (2008, J. Arthroplasty)

13. MECHANICAL EFFECTS Limb Exsanguination Pressure Under the Pneumatic Tourniquet The Mass of Tissue Under the Pneumatic Tourniquet Tissue Injury Skin Muscle Nerves Vessels

14. The Mass of Tissue Under the Pneumatic Tourniquet The mass of tissue affected by the PT is greater in the lower than the upper limbs The shape of the PT is critical A straight tourniquet cannot fit a limb with a conical shape, particularly in obese patients

15. The Mass of Tissue Under the Pneumatic Tourniquet A wide cuff (ie, more than 5 cm for the upper and 9 cm for the lower limb) is much more effective in the occlusion stage than a narrow cuff and can be painless when pressure is limited to the lowest effective level Despite a possible risk of increased nerve injury, the widest curved cuff appropriate to the size of the extremity should be selected and must be connected to an integrated cuff inflation system

16. MECHANICAL EFFECTS Limb Exsanguination Pressure Under the Pneumatic Tourniquet The Mass of Tissue Under the Pneumatic Tourniquet Tissue Injury Skin Muscle Nerves Vessels

17. Tissue Injury- Skin Wrinkle-free padding beneath the tourniquet is essential to reduce skin damage because of shearing stress To avoid chemical burns beneath the tourniquet, it must be separated from the operative field by a self-adhesive plastic drape before skin preparation Because of the high rate of contamination of nonsterile reusable PTs (68%), it could be preferable to use a sterile PT to reduce potential sources of infection The tourniquet cuff should not be rotated to a new position after it is applied because shearing forces from rotating the cuff may damage underlying tissues

18. MECHANICAL EFFECTS Limb Exsanguination Pressure Under the Pneumatic Tourniquet The Mass of Tissue Under the Pneumatic Tourniquet Tissue Injury Skin Muscle Nerves Vessels

19. Tissue Injury- Muscle There is evidence that compression injury owing to the tourniquet results in a more significant loss of muscle functional strength, contractile speed, and fatigability than tourniquet-induced ischemia

20. MECHANICAL EFFECTS Limb Exsanguination Pressure Under the Pneumatic Tourniquet The Mass of Tissue Under the Pneumatic Tourniquet Tissue Injury Skin Muscle Nerves Vessels

21. Tissue Injury- Nerves Temporary nerve injuries may be underdiagnosed because of postoperative limb weakness and the rapid recovery of the nerves Nerve injuries do occur at higher PT cuff pressures and after prolonged tourniquet inflation Animal models have demonstrated that nerve injury is more pronounced beneath the cuff than distal to it

22. Tissue Injury- Nerves Mechanical deformation is associated with myelin disturbance, demyelination, and Wallerian degeneration A short duration (4 to 13 min) of compression is sufficient to impair the transmission of stimuli and cutaneous afferents The occurrence of electromyography (EMG) abnormalities has been noted during and after tourniquet use, and these abnormalities may persist for up to 6 months afterward

23. Tissue Injury- Nerves Tourniquet pain can be explained by ischemia and compression, but it is increased with hyperalgesic phenomena Thus, in addition to local mechanisms, sensitization of the central nervous system may also play a part in the tourniquet pain process In the absence of regional or general anesthesia, the topical application of EMLA cream is effective in providing semicircular subcutaneous anesthesia and reducing tourniquet pain Morphine added to a lidocaine epidural solution during regional anesthesia significantly delays the onset of tourniquet pain

24. MECHANICAL EFFECTS Limb Exsanguination Pressure Under the Pneumatic Tourniquet The Mass of Tissue Under the Pneumatic Tourniquet Tissue Injury Skin Muscle Nerves Vessels

25. Tissue Injury- Vessels Tourniquet use may also damage the intravascular endothelium Arterial complications after TKA are rare but the consequences can be disastrous (eg, vascular reconstruction or amputation), particularly in the presence of peripheral arterial disease or ipsilateral prior peripheral arterial reconstruction Careful monitoring of the vascular status of the limb (ie, distal pulses and capillary refill) is required in the early postoperative period to detect any vascular compromise

26. ISCHEMIA REPERFUSION EFFECTS Duration of Ischemia Tourniquet Release, Effects of Reperfusion Generalities Skin Muscle Nerves Vessels

27. Duration of Ischemia The “safe” duration of tourniquet-induced ischemia remains controversial Tourniquet application> 60 mins increases the risk of complications after arthroscopy However, 3 hours of continuous ischemia will not produce generalized irreversible damage in healthy muscle, although it will result in widespread sublethal injury to cells

28. Duration of Ischemia The maximum recommended period of tourniquet-induced ischemia is 1 hour If tourniquet use exceeds one hour, it is common practice to deflate the PT intermittently in an attempt to minimize the ischemic damage Reperfusion periods can be initiated within 45 to 60 minutes of ischemia (tourniquet downtime technique) and must be longer than 10 minutes to be beneficial

29. Duration of Ischemia Reperfusion initiated after 2 ischemic hours tends to exacerbate muscle injury Releasing the PT before wound closure was proposed to reduce the duration of ischemia Severe complications such as acute vascular damage can be avoided if the PT is released for hemostasis

30. ISCHEMIA REPERFUSION EFFECTS Duration of Ischemia Tourniquet Release, Effects of Reperfusion Generalities Skin Muscle Nerves Vessels

31. Tourniquet Release, Effects of Reperfusion- Generalities Tourniquet release is associated with an immediate 10% increase in limb girth (refilling of the vessels and hyperemia) This causes an increase in intracompartmental pressure in the reperfused limb Over the first postoperative day, the initial limb girth can increase by as much as 50%

32. Effects of Reperfusion- Generalities Releasing the tourniquet prior to hemostasis and closure reduces inflation time, allowing for a period of reperfusion and swelling before bandage or cast application This may reduce potential complications Deflation should be quick to prevent capillary bleeding

33. Effects of Reperfusion- Generalities Ischemia Reperfusion ( IR) results in a complex cascade of responses that can lead to muscle degeneration and loss of function M anifestations of IR remains difficult to identify Signs of primary injury (vasodilation and erythema) have been observed immediately after 1 hour of tourniquet use

34. Effects of Reperfusion- Generalities Secondary injury presents as a progression of cell injury despite reperfusion, which can lead to a “no-reflow phenomenon” in which blood flow does not return to all areas after a long period of ischemia Leukocytes play a significant role in this phenomenon, through adhesion to postcapillary venules, microvascular barrier disruption, and edema formation

35. Effects of Reperfusion- Generalities Described in 1951, the “post-tourniquet syndrome” combines weakness, stiffness, edema, dysesthesia, and pain These symptoms may be mistakenly attributed to surgical trauma or to lack of patient motivation

36. ISCHEMIA REPERFUSION EFFECTS Duration of Ischemia Tourniquet Release, Effects of Reperfusion Generalities Skin Muscle Nerves Vessels

37. Skin Risk factors for infectious complications include prolonged tourniquet inflation time Wound hypoxia during lower limb orthopedic surgery is greater with tourniquet use than without Tourniquets (and exsanguinators) can be a potential source of infection

38. Skin Parenteral prophylactic antibiotics must be administered at least 10 to 20 minutes before tourniquet inflation and isolation of the operative site from the systemic circulation After inflation of the tourniquet, antibiotics may not reach the exsanguinated limb

39. Skin If the tourniquet has been inflated, regional intravenous injection of an antibiotic is a good alternative However, antibiotic administration 10 minutes before the PT release seems to be as effective as administration before inflation

40. ISCHEMIA REPERFUSION EFFECTS Duration of Ischemia Tourniquet Release, Effects of Reperfusion Generalities Skin Muscle Nerves Vessels

41. Muscle Skeletal muscle may be severely affected, even with relatively short periods of ischemia After ACL reconstruction, the amount of vastus muscle amyotrophy after tourniquet use is significantly greater than without tourniquet use Similar reduction in quadriceps function was reported after TKA without significant effect on cement interface quality

42. Muscle Cases of rhabdomyolysis with acute renal failure, and compartment syndrome have been reported after tourniquet duration of more than 4 hours , but also with shorter inflation times ( 45 to 120 min ) Interestingly, loss of strength, or electromyographic abnormalities, can also be observed in the contralateral limb, suggesting a sensitization of the central nervous system

43. Muscle damage- mechanism During ischemia adenosine triphosphate (ATP) depletion Acidosis and ion imbalance occurs During reperfusion C ytokine production reactive oxygen species (ROS) and rapid calcium influx into the cells causes mitochondrial dysfunction that leads to cellular apoptosis and necrosis

44. ISCHEMIA REPERFUSION EFFECTS Duration of Ischemia Tourniquet Release, Effects of Reperfusion Generalities Skin Muscle Nerves Vessels

45. Nerves Limb dysfunction during ischemia and reperfusion may be largely the result of axonal or neuromuscular junction injury, or both The factors that incite the ischemic nerves to spontaneously discharge and cause paresthesia upon reperfusion are not understood

46. Nerves In a prospective randomized study performed with simultaneous bilateral TKA, a clear decrease in thigh pain was reported in the group with lower PT pressure To effectively reduce pain, intraarticular injection of local anesthetics must be performed 10 minutes before tourniquet deflation, to allow fixation of local anesthetics before the washout period of tourniquet release, or 30 minutes after PT deflation

47. ISCHEMIA REPERFUSION EFFECTS Duration of Ischemia Tourniquet Release, Effects of Reperfusion Generalities Skin Muscle Nerves Vessels

48. Vessels The risk of DVT is significantly increased with a tourniquet time of more than 60 minutes Following knee arthroscopy, the incidence of DVT diagnosed using contrast venography is approximately 18% 1 week after surgery

49. Vessels The formation of DVT begins during tourniquet inflation and continues after deflation owing to an increase in circulating markers of thrombosis plasma D-dimer tissue plasminogen activator angiotensin-converting enzyme antithrombin-III protein C Close monitoring of coagulation factors could help detect asymptomatic venous thromboembolism (VTE) after TKA

50. Vessels In randomized studies, tourniquet use during TKA does not reduce total blood loss A meta-analysis of TKA surgery confirms that there is an initial increase in blood loss in groups without PT use, but no significant difference in total perioperative blood loss or transfusion in comparison with PT groups

51. Vessels An increase of local fibrinolysis postoperatively after PT deflation, secondary to the release of anticlotting factors from the surgical site, may explain the increased risk of bleeding into the joint or drains The benefit of surgical hemostasis after tourniquet deflation is still under debate because of the risk of increased blood loss, but prospective studies support intraoperative PT release

52. SYSTEMIC EFFECTS General Cardiovascular Pulmonary Neurologic

53. General Just after the deflation of the tourniquet, anesthetic drugs sequestered in the exsanguinated limb are released and may be clinically detected when the bispectral index is used May be clinically important in older adults/ debilitated patients

54. SYSTEMIC EFFECTS General Cardiovascular Pulmonary Neurologic

55. Cardiovascular The mean arterial pressure increases progressively after tourniquet inflation secondary to pain Regional anesthesia is more effective than GA for moderating this

56. Cardiovascular Preoperative intravenous injection of a small dose of Ketamine dexmedetomidine or clonidine magnesium sulfate dextromethorphan can reduce this increase in systolic arterial pressure

57. Cardiovascular A brief period of hypotension upon PT deflation, secondary to Metabolic acidosis Lactic acidosis and Hyperkalemia can cause myocardial depression and even cardiac arrest in older adults or debilitated patients after prolonged lower limb surgery

58. Cardiovascular Postoperative hypovolemia may be observed after tourniquet deflation due to hemorrhage at the surgical site a combination of reactive vasodilation and increased microvascular permeability in the reperfused limb

59. SYSTEMIC EFFECTS General Cardiovascular Pulmonary Neurologic

60. Pulmonary Fatal or near-fatal pulmonary embolism (PE) was first reported after use of the Esmarch bandage + /- tourniquet inflation in orthopedic surgery (reported after tourniquet deflation) There is a significant correlation between the occurrence of emboli and the duration of tourniquet application Emboli occur during PT inflation and femur reaming in 27% of patients, and in 100% of patients after tourniquet deflation

61. Pulmonary Pulmonary embolism occurring during orthopedic surgery can result from a fat embolism owing to invasion of the medullary cavity Air and cement emboli have also been reported after tourniquet release Acute lung injury (ALI) can be observed after limb reperfusion (increased microvascular permeability sequestration of neutrophils generation of oxygen-free radicals)

62. Pulmonary The powerful neutrophil activation causes oxidative stress and has been used in an animal model to develop “tourniquet shock” by applying two tourniquets simultaneously on both lower limbs of an animal

63. SYSTEMIC EFFECTS General Cardiovascular Pulmonary Neurologic

64. Neurologic Tourniquet deflation leads to CO2 production and systemic blood pressure- r esulting in increase in intracranial pressure (ICP) This leads to a severe reduction in cerebral perfusion pressure causing brain injury

65. TREATMENT OF ISCHEMIA PERFUSION INJURY

66. TREATMENT Ischemic preconditioning, defined as a brief period of ischemia followed by tissue reperfusion, can be used Nitric oxide synthase (NOS) and heme oxygenase (HO) have been implicated in this process These effects can be partially explained by humoral factors and/or neurologic pathways

67. TREATMENT Prostaglandins or their analogues do not seem, experimentally, to reduce muscle injury Antioxidants have a cytoprotective effect that could be attributed to the inhibition of neutrophil adherence activation and scavenging of superoxide radicals In humans, inhaled nitric oxide (NO) before, during, and after the PT application reduces inflammation in lower limb extremities

68. TREATMENT HO and carbon monoxide may also be beneficial because carbon monoxide has a very similar action to Nitric Oxide (NO) Administration of an endothelial xanthine oxidase inhibitor ( allopurinol ) or a radical scavenger such as vitamin E can decrease oxidative stress and the occurrence of edema in postischemic skeletal muscle Edaravone , another free-radical scavenger, when given during early reperfusion, seems to be effective in reducing nerve injury as a result of oxidative stress

69. TREATMENT To reduce microvascular reperfusion injury following tourniquet ischemia in striated muscle, buflomedil or flurbiprofen can also be used Local hypothermia by cold gel packs reduces metabolic demand by reducing ischemic and anoxic degeneration, but although it could be effective during ischemia, it may aggravate injury after reperfusion Phosphodiesterase type 3 inhibitors (M ilrinone and Cilostazol) can be used as inodilators (ie, positive inotropes and arteriovenous dilators) to reduce DVT

70. TREATMENT A perioperative infusion of milrinone can significantly attenuate platelet activation and monocyte tissue factor expression during a TKA without increasing perioperative blood loss Regional limb heparinization is not effective in reducing embolic phenomena after PT release

71. CONCLUSION

72. Conclusion I t is difficult to establish an overview of the existing evidence on PT use In practice, the PT is a useful tool for good visualization in extremity surgery but it carries a risk of adverse effects It is necessary to weigh the advantages and disadvantages before deciding to use a PT The main indication should NOT be the hemostatic effect of the tourniquet because elevation, step-by-step hemostasis and pharmacologic vasoconstriction may also be used to obtain a bloodless field

73. Conclusion R elative contraindications severe atherosclerotic disease severe crush injuries diabetes mellitus sickle-cell disease severe brain injury Proven or suspected DVT presence of calcified vessels rheumatoid arthritis other collagen-vascular diseases associated with vasculitis localized tumors

74. Conclusion- Techniques to minimise adverse effects T he tourniquet must be used within the framework of strict procedures and protocols with well-adapted and regularly checked equipment The location of the PT must be as distal as is surgically possible The arterial occlusion pressure must be measured, and the PT inflated to an arterial occlusion pressure plus 50 to 75 mm Hg (or 75 to 100 mm Hg greater than systolic blood pressure ) Tourniquet duration should ideally be less than 1 hour

75. Conclusion- Techniques to minimise adverse effects Reperfusion periods can be initiated within 45 to 60 minutes of ischemia for longer tourniquet times To keep the duration of ischemia as short as possible, tourniquet deflation prior to hemostasis and closure is preferable After deflation, monitoring of the vascular and neurologic status of the limb must be performed regularly, so a temporary bandage or split plaster cast should be used for the first 2 postoperative days to allow space for swelling and to permit evaluation of the limb

76. THANK YOU Rajagiri Hospital/ Libin Thomas/ 2024