Updated: 4/6/2020

Blood Loss Management in Spine Surgery

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Preoperative Management
  • Preoperative hemoglobin optimization (focus on reducing allogenic blood transfusion intraoperatively and postoperatively)
    • vitamin supplementation
      • iron
        • major building block of hemoglobin and functions to bind oxygen in the porphyrin ring structure
        • supplementation provides material for hemoglobin synthesis
        • some studies have demonstrated a significant decrease in postoperative transfusions in patients with anemia-reducing vitamins
        • increased side effects
          • constipation
          • heartburn
          • abdominal pain
      • folate and vitamin B12 supplementation
        • are essential vitamins for DNA synthesis that is necessary for erythropoiesis
      • anemia-associated vitamin supplemenation
        • iron 256 mg/day, vitamin C 1 g/day, and folate 5 mg/day for 30-45 days preopeative have been associated with decreased transfusion rates
          • should only be used in patients with specific deficiency
    • erythropoietin (EPO)
      • recombinant protein of natural glycoprotein produced by renal pericapillary cells
        • signals bone marrow cells to stimulate RBC production
      • studies have demonstrated greater efficacy than preoperative autologus blood donation and reinfusion systems
      • high cost associated with use
        • treatment cost equivalent to 4 units of allogenic blood transfusion
      • recommended for high risk patients
        • preoperative Hb < 13g/dL
        • low body weight (< 50 kg)
        • surgies when considerable blood loss is expected
      • three dosing regimens have been proposed:
        • 600 IU/kg - 4 doses: preoperative days 21, 14, 7, and 0
        • 300 IU/kg - 15 doses: preoperative day 10 to postoperative day 4
        • 150 IU/kg - 9 doses: preoperative day 5 to postoperative day 3
    • preoperative autologous blood donation
      • preoperative procurement of 1 to 2 units of autologous blood
      • performed at least 3 weeks from the planned surgery to allow for recovery of Hb levels
      • current literature does not seem to support efficacy and cost effectiveness in the management of postoperative anemia
        • concerns that there is a high incidence of unused units
        • compulsion to transfuse patient
      • may be of benefit in patients with normal Hb (>14 g/dL) ubdergoing procedures with high expected blood loss
        • may be performed in any patient with Hb > 11 g/dL and body weight >50 kg performed with sufficient time prior to procedure
    • preoperative embolization
      • standard treatment for oncology cases with highly vascular tumors
        • renal cell carcinoma
      • performed within 24 hours of the procedure
  • Discontinuing anticoagulating medications prior to surgery
    • NSAIDs
      • inhibit COX-1 and COX-2 
    • nonaspirin platlet inhibitors (clopidogrel)
      • commonly prescribed after cardiac stenting 
        • elective spine surgery should be postponed after such procedures
          • 6 weeks bare metal stents
          • 6 to 12 months drug-eluting stents
        • if urgent/emergent surgery may consider continuing medication
          • if discontinued, need to discuss risks and benefits
        • Plavix can be resumed 12 to 24 hours after surgery if there is no concern for epidural hematoma
    • long-term anticoagulants
      • risk of thromboembolic event with discontinuation prior to procedure
      • Warfarin
        • discontinue 5 days prior to procedure
        • goal INR <1.4
        • resuming immediately after procedure would lead to subtherapeutic INR for 8 to 10 days
          • may consider bridging agent with these patients
      • Low-molecular-weight heparin or unfractionated heparin
        • therapeutic dosing should be postponed minimum of 48 to 72 hours after spine surgergy to prevent epidural hematoma
    • supplements
      • should be discontinued 14 days prior to surgery to minimize intraoperative blood loss
        • decrease platlet aggregation
          • garlic
          • ginkgo
          • ginseng
          • fish oil
          • flax seed oil
          • saw palmetto
        •  inhibits clotting
          • chamomile
        • alter coagulation
          • vitamin E
          • vitamin K
          • green tea (contains vitamin K)
Anticoagulating Medications
Drug Plasma Half-Life (hours) Effect on Bleeding Minimum Cessation Prior to Surgery (days)
Diclofenac 1-2 Inhibits COX (reversibly) 1
Ibuprofen 2 Inhibits COX (reversibly) 1
Indomethacin 4-10 Inhibits COX (reversibly) 3
Ketorolac 5-7 Inhibits COX (reversibly) 3
Etodolac 6-7 Inhibits COX (reversibly) 3
Sulindac 8-16 Inhibits COX (reversibly) 3
Naproxen 12-17 Inhibits COX (reversibly) 3
Piroxicam 50 Inhibits COX (reversibly) 7
Celecoxib 11 Inhibits COX-2 (reversibly) 1
Aspirin 6 Inhibits COX (irreversibly) 7
Clopidogrel 1 Irreversibly inhibits platlet ADP receptors 7
Prasugrel 2-15 Irreversibly inhibits platlet ADP receptors 7
Ticagrelor 7-9 Reversibly inhibits platlet ADP receptors 5
Ticlopidine 20-50 Irreversibly inhibits platlet ADP receptors 14
Warfarin 20-60 Inhibits vitamin K-dependent clotting factor synthesis


Enoxaparin (LMWH) 3-5 Binds antithrombin and irreversibly blocks thrombin 1
Unfractionated heparin 0.5-2 Binds antithrombin and irreversibly blocks thrombin 4-5 h
Dabigatran 7-14 Reversibly blocks thrombin 3
Rivaroxaban 5-13 Reversibly blocks thrombin 3
Apixaban 9-14 Reversibly blocks thrombin 3
Edoxaban 10-14 Reversibly blocks thrombin 3
    • other medications
      • valproic acid
        • antiepileptic medication
        • affects platlet function
        • associated with increased intraoperative blood loss
        • will not affect preoperative laboratory tests
      • SSRIs and SNRIs
        • increased blood loss associated in adult lumbar spine surgery
        • should discuss discontinuation of these medications for high blood loss procedures
  • Preoperative blood loss estimation
    • allows for cost-effective treatment with cell salvage systems, allogenic blood transfusions, and antifibrinolytic agents
    • factors associated with increased blood loss
      • increased body mass index
      • lower body weight
        • mostly associated with increased transfusion requirements
        • lower starting blood volume
        • factor for pediatric spinal deformity
      • advanced age
      • bleeding diatheses
      • number of spinal levels 
        • approximately 200 cc per lumbar level
      • use of instrumentation
      • revision spine surgery
      • iliac crest bone harvest
      • interbody fusions
      • trauma or tumor surgery
      • Cobb angle >50°
      • longer expected surgical time
      • neuromuscular scoliosis
      • >6 levels fused for deformity surgery
      • Ponte osteotomies
      • vertebral column resection osteotomy
        • can lead to 65% total blood volume loss
    • recommend obtaining a preoperative hemoglobin level of 5 g/dL greater than treating surgeons transfusion trigger
Preoperative Labs
  • CBC
    • hemoglobin & hematocrit
    • platlets
  • Prothrombin time (PT)
    • determines clotting time for the extrinsic coagulation cascade
      • factors I, II, V, VII, and X
      • normal result is 12-13 seconds
      • reported with International Normalized Ratio (INR)
        • normal range of 0.8 to 1.2
    • not correlated with increased transfusion rates
  • Partial thromboplastin time (PTT) 
    • assesses clotting time of the intrinsic clotting cascade
    • factors XII, XI, IX, VIII, X, V, II
    • normal range of 25-39 seconds
    • not correlated with increased transfusion rates
  • Fibrinogen 
    • also known as factor I
    • normal range 200-400 mg/dL
    • below normal ranges have been associated with increased transfusion rates 
Intraoperative Management
  • Hypotensive anesthesia
    • administration of vasodilating agents to a goal systolic blood pressure of 50 - 80 mm Hg or MAP of 60 mm hg
      • well validated in pediatric scoliosis surgery
      • has been shown to decrease intraoperative blood loss by 55% without sequelae
      • reduces blood extravasation through surgical wound
      • does not affect bone bleeding (mostly venous bleeding)
    • complications:
      • concern for possible cord transfusion
        • neuromonitoring changes
        • address by increasing blood pressure, ensuring no halogenated gases, determine last time when gentamicin was given, and increase patient temperature
      • ischemic optic neuropathy
  • Maintenance of normothermia
    • ideal to keep body temperature >36° C
      • decrease in body temperature >1° C can increase blood loss by 16% and increase transfusion rates by 22%
      • hypothermia decreases platlet function and coagulation enzyme activity
    • increase OR temperature if needed
    • minimize exposed skin surface-area until drapping
  • Patient positioning
    • reverse trendelenburg positioning 
      • decrease central venous pressure 
    • Jackson frames that allows abdomen to hand freely 
      • decrease intra-abdominal pressure and pressure on inferior vena cava
        • prevent congestion in Batson venous plexus
  • Tranexamic acid (TXA)
    • lysine derivative that competitively blocks plasmin binding sites on fibrin
      • results in a decrease in fibrinolysis and stabilized clot formation 
      • 6 to 10 times more potent than epsilon aminocaproic acid
    • multiple studies have demonstrated a significant reduction in operative blood loss and transfusion rates with perioperative administration
      • no increased risk of DVT and PE 
      • does not alter PT and PTT times
    • multiple dosing regimens and routes of administration utilized
      • IV, oral, and topical all appear equally efficacious
    • contraindications:
      • history of CVA
      • allergy
      • severe CAD
    • side effects:
      • seizures
        • binds to glycine and GABA channels leading to a reduced seizure threshold
  • Desmopressin
    • vasopressin analog
      • increases factor VIII and von Willebrand factor
    • limited data in spine surgery
    • useful treating patients with von Willebrand's disease
  • Surgical techniques
    • local anesthetic with epinephrine
      • can prevent dermal bleeding over long cases 
        • 1:500,000 epinephrine
    • subperiosteal elevation
      • preserves vasculature of paraspinal muscules
    • electrocautery
      • monopolar
        • soft tissue and periosteal elevation
        • ensure not to violate ligamentum in the interlaminar space
          • could go intradural
      • bipolar
        • ideal for hemostasis near neural structures
          • epidural space
          • coagulating bleeding epidural veins
      • saline-irrigated radiofrequency bipolar hemostatic sealers
        • contracts vascular collagen at temperatures <100° C
          • unipolar cautery reaches temperature >300° C
        • studies have shown substantial blood loss reduction in pediatric deformity surgery
        • increased surgical cost of $493 per case
    • wound-packing
      • surgical areas that are not being addressed should be packed
        • decreases low-pressure bleeding
      • saline-soaked sponges or patties
        • can be combined with thrombin or epinephrine for greater hemostasis control
  • Aminocaproic acid
    • lysine derivative that competitively inhibits plasmin 
      • results in decreased fibrinolysis
    • studies have demonstrated decreased blood loss with aminocaproic acid in arthroplasty
    • lower cost than TXA
    • does not decrease seizure threshold
  • Topical hemostatic agents 
    • collagen agents
      • stimulate the instrinsic pathway of coagulation cascade to promote hemostasis 
      • microfibrillar collagen
        • dry, fine, white powder
        • must be applied with dry surgical instruments to a dry field
    • fibrin sealant
      • consists of two seperate mixtures
        • one contains fibrin and factor XIII
        • one contains thrombin and calcium
      • combining the mixtures creates a fibrin seal where it is sprayed
    • platlet-rich plasma 
      • centrifugation of patient's blood to isolate plasma with high contents of platlets, growth factors, and clotting factors
      • proposed benefit of improved hemostasis, wound healing and recovery
    • platlet-poor plasma
      • isolated from centrifugation process
      • combined with thrombin and calcium to provide an autologous fibrin sealant
    • gelfoam sponges
      • manufactured from animal-skin gelatin and processed into sponge-form
      • isolated use exerts mostly mechanical hemostasis against low-pressure bleeders
      • can be soaked with thrombin, which can act as as scaffold for the coagulation cascade
      • excess gelfoam should be removed as it may interfere with bone healing
    • topical hemostatic agents do not appear to be cost-effective in total joint arthroplasty cases
      • beneficial in spine surgery to promote hemostasis without inflicting harm to adjacent neural structures
    • topical TXA
      • typically administered near the end of the procedure to control postoperative bleeding
      • decreases fibrinolysis and stabilizes clot formation
      • may be an alternative route of adminstration in patients with higher risk of complications
        • history of MI, CAD, or CVA
    • gelatin-thrombin matrix
      • commonly used in spine surgery to control epidural bleeding
        • brand names include Floseal and Surgiflo
      • consists of porcine or bovine gelatine matrix combined with human derived thrombin
      • acts of the end stage of the coagulation cascade leading to fibrin formation
  • Reinfusion systems (cell saver)
    • recycles intraoperative blood loss for later transfusion
      • can be transfused intraoperatively during longer procedure 
    • shed blood is filtered, washed, and transfused within 6 to 8 hours from the procedure
      • serves as an alternative to allogenic blood transfusion
      • theoretical benefits of minimizing wound complications and hematoma formation
      • need to avoid suctioning antibiotic irrigation, povidone-iodine solution, and irrigation >42° C into the circuit
    • indications:
      • religious beliefs that preclude allogenic blood transfusion
      • large number of autoantibodies that makes allogenic blood stock incompatible
    • contraindications:
      • surgies for malignancy and infection
    • not recommended for routine use in lumbar spine surgery
      • not cost effective unless blood loss ≥500 cc
    • complications:
      • coagulopathy
        • altered composition of the transfused blood containing elevated fibrin split products and inflammatory cytokines (TNF-α and interleukins)
          • especially problematic in unwashed systems
        • can lead to increased wound drainage
        • recommended to transfuse 1 unit of FFP for every 1,000 cc of volume of returned
      • transient hemoglobinuria
      • pulmonary complications
        • due to reperfusion of debris
      • contamination
      • cost
Postoperative Management
  • Allogenic blood transfusion
    • preoperative hemoglobin strongest risk factor for postoperative blood transfusion
      • below 13 g/dL more likely
    • other risk factors
      • female gender
      • increased age
      • larger patient size
      • longer procedures
      • lateral releases in total knee arthroplasty
    • 1 unit increased Hb by 1 g/dL
    • no absolute criteria for transfusion
      • transfusion should be considered for anyone with Hb <6 g/dL
      • transfusion should be considered for postoperative patients with Hb 7-8 g/dL
      • routine transfusion should be avoided for Hb > 8 g/dL
        • no increased mortality has been seen with this criteria, even in patients with cardiac history
        • initiate transfusion if patient is symptomatic
          • orthostatic hypotension
          • tachycardia unresponsive to fluids
      • Hb levels between 6 to 8 g/dL should be based on patient factors
        • expectation of continued blood loss
        • intravascular volume status
        • cardiovascular reserve
        • response to anemia
    • complications
      • increased risk of nosocomial infections
        • immunomodulatory effects
          • increased SSI
          • increased UTIs
      • viral transmission
        • hepatitis B - 1:205,000 unit donated
        • hepatitis C - 1:1.8 million units donated
        • human immunodeficiency virus - 1:1.9 million units donated
      • transfusion-related acute lung injury (TRALI)
        • immunologically mediated damage to the lungs
        • can result in adult respiratory distress syndrome
      • acute hemolytic reaction
        • potentially lethal complication
        • results from blood-type mismatch
          • rare complication
  • Allogenic platlet transfusion
    • blood product most likely to be contaminated
      • stored at room temperature
      • infections in 10 cases per million units transfused
      • gram positive organisms most common
    • thrombocytopenia
      • platlet count below 5,000/mm^3
        • give platlets to avoid spontaneous bleeding
      • platlet count below 50,000/mm^3
        • give platlets before surgery
      • platley count above 100,000/mm^3
        • no need to transfuse
  • Postoperative iron supplementation
    • daily oral iron replacement mild acute blood loss anemia
  • Drains
    • theoretically prevents surgical site hematomas
      • potential site for infection or neural compression
    • concern for increased post-operative blood
      • negates the tamponade effect by decreasing intrawound pressure
Special Considerations
  • Jehovah's Witness (JW)
    • hold beliefs that blood transfusions are forbidden by the bible
      • some patients may still consent to a blood transfusion
      • some patients may consider the use of cell saver as an alternative to allogenic blood transfusion
    • use of colloids and coagulation factors are not forbidden and a matter of personal choice
    • bovine-derived hemostatic agents are generally approved by JW
      • products derived from human plasma are a personal decision of JW
        • preoperative discussion about the use of the use of these agents 

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