Hemostasis is a complex series of physiological processes in which vascular tone, blood flow, endothelial cells, platelets, leukocytes, coagulation factors, and fibrinolytic factors interact through initiation, amplification, and propagation.1 Effective hemostasis depends on an adequate number of functional platelets combined with an appropriate concentration and activity of plasma coagulation and fibrinolytic proteins.1 Fibrinogen is converted to fibrin through an enzymatic reaction resulting in an insoluble clot and is thus essential for hemostasis.2,3 Additionally, fibrinogen participates in wound healing and other biological functions.2 The balance of fibrin formation and fibrinolysis regulates the size and quality of clot formation at the site of injury, which has a significant impact on how effectively hemostasis is achieved.3 Preoperative anemia has been associated with a high risk of developing deep vein thromboembolism in elective orthopedic surgeries, thus suggesting Hct does affect the clotting cascade making it an important factor when evaluating coagulation.4,5 However, the mechanism of thrombosis formation as it relates to low Hct is still unclear.4 The adhesion and aggregation of platelets at the site of injury result from platelet activation; therefore, changes in platelet numbers also impact the clotting cascade.5 The diagnosis, treatment, and monitoring of hypo- and hypercoagulable states in animals is difficult in regards to both progression of disease and measurement of blood components.6 The traditional diagnostic approach to evaluating the hemostasis systems includes assessing primary hemostasis (vascular tone and platelet plug), secondary hemostasis (coagulation), fibrinolysis (clot breakdown), and the presence of endogenous anticoagulants, which limit the clot formation at the site of injury.6 Prothrombin time and activated partial thromboplastin are commonly used to measure the activity of the intrinsic, extrinsic, and common pathways.7 These tests are useful but limit the evaluation to mostly hypocoagulation.8 Viscoelastic point-of-care coagulation devices provide an assessment of clot formation, clot development, and fibrinolysis.9,10 Therefore, viscoelastic testing not only determines hypocoagulability but also identifies hypercoagulable, hyperfibrinolytic, and hypofibrinolytic states.7 The use of this technology has been shown to improve the diagnosis of hemostatic disorders. It evaluates multiple components of coagulation including platelets, RBCs, coagulation factors, and thrombin.10 These diagnostics are beneficial when evaluating hypercoagulable states in patients undergoing elective orthopedic procedures to determine if appropriate corrective treatments are indicated.11–13 However, the need for special equipment, cost, user error, and accessibility are limitations of such viscoelastic testing.14,15 Viscoelastic coagulation was evaluated on a novel bedside analyzer (Viscoelastic Coagulation Monitor [VCM] Vet; Entegrion Inc) providing results within 60 minutes with a reasonable cost, ease of use, and standardized reference intervals.16–18 Evaluation of elective orthopedic surgeries on VCM parameters and fibrinogen concentrations is not well described in veterinary literature. This study aimed to identify the effects of stifle arthroscopy and tibial plateau leveling osteotomy (TPLO) on VCM, fibrinogen concentrations, Hct percentages, and platelet numbers preoperatively, immediately postoperatively, 24 hours and 14 days postoperatively in otherwise healthy dogs. The null hypothesis states elective stifle arthroscopy and TPLO surgery would not significantly affect VCM results and fibrinogen concentrations in healthy animals.
Methods
Study design
This prospective observational study was performed at Gulf Coast Veterinary Specialists with consent forms used to enroll client-owned dogs. The clinical study was approved by the Medical Clinical Studies Board sub board of the Specialty Advisory Board for National Veterinary Associates-Compassion First.
Animals
Fifty-two client-owned dogs who presented for stifle instability were enrolled, 15 were excluded because they were missing observations for several variables due to lack of owner follow-up compliance, therefore making the final total n = 37. The mean age was 6.14 years with a range of 1.9 to 12.17 years. The majority of the dogs were spayed females. The mean weight was 32.5 kg with a range of 6.9 to 58 kg. Mixed-breed dogs (37%) and Labrador Retrievers (27%) were overrepresented. A variety of other breeds were represented in this study; descriptive details are provided (Table 1). All dogs were otherwise healthy based on physical examination, CBC, blood biochemistry profile, and previous history. Exclusion criteria included any dog that had cardiovascular, renal, liver, or endocrine diseases. Furthermore, dogs with a history of thrombosis, embolism, known malignancy, or previous orthopedic disease were excluded.
Summary of descriptive statistics for the 37 enrolled dogs for elective stifle arthroscopy and tibial plateau leveling osteotomy (TPLO).
| Parameters | Statistics |
|---|---|
| Age (y) | |
| Range | 1.92–12.17 |
| Mean | 6.14 |
| Sex (n) | |
| Male | 1.0 |
| Neutered male | 13.0 |
| Female | 2.0 |
| Spayed female | 21 |
| Weight (kg) | |
| Range | 6.9–58.6 |
| Mean | 32.54 |
| Breeds | |
| Australian Cattle Dog | 1 |
| Labrador Retriever | 10 |
| Great Dane | 1 |
| Bull Mastiff | 1 |
| Rottweiler | 2 |
| Mixed breed | 14 |
| English Springer Spaniel | 1 |
| Standard Poodle | 1 |
| Golden Retriever | 1 |
| American Bulldog | 1 |
| Black Mouth Cur | 1 |
| Pointer | 1 |
| Boxer | 2 |
Data collection
Patients included in the study were dropped off the morning of surgery and fasted the night before. Blood was collected at 4 different time points: prior to anesthetic event, just prior to extubation, 24 hours after extubation, and at the 2-week postoperative recheck evaluation. At each time point, 5 mL of fresh whole blood was drawn from the right or left jugular vein by a licensed veterinary technician with either a 20- or 22-gauge needle attached to a 5-mL syringe (Monojet Luer Lock syringes; Terumo). Viscoelastic testing, Hct percentages, fibrinogen concentrations, and platelet numbers were measured for each time point. This collection and processing protocol is in accordance with Partnership on Rotational ViscoElastic Test Standardization (PROVETS) guidelines.19 Approximately 0.3 mL of whole blood was used for VCM testing, 2 mL of whole blood was used for fibrinogen concentration, and 2 mL of whole was used blood for CBC count and biochemistry. The initial blood draw prior to anesthesia included a biochemistry panel to evaluate for renal, liver, and or endocrine diseases.
Two VCM devices were utilized for whole blood analyses. Quality control system checks following the manufacturer's directions on each device were performed daily prior to blood sampling and testing.16 A VCM heating plate was used to prewarm the corresponding cassettes to 37 °C per manufacturer guidelines. At each time point immediately following fresh whole blood collection, approximately 0.3 mL was transferred to the preheated cassette reservoir and inserted into the VCM device, and the test was started automatically and ran for 60 minutes. VCM measured variables were clot time, clot formation time, alpha-angle (α), amplitude at 10 and 20 minutes, maximum clot firmness, and clot lysis at 30 and 45 minutes. These results were compared between time points for each patient and normal reference intervals. Additionally, whole blood was transferred to 3.2% sodium citrate (2 mL) and EDTA (2 mL) tubes to measure fibrinogen concentrations and CBC counts, respectively. Sodium citrate samples were centrifuged at (270 X g for 15 minutes), and the plasma was then transferred to a sterile plastic collection container with no additives for fibrinogen evaluation and sent to IDEXX BioAnalytics. The CBC and biochemistry panels were run through the in-hospital laboratory on the IDEXX ProCyte Dx (IDEXX Laboratories) and IDEXX Catalyst One (IDEXX Laboratories).
Anesthesia
An IV catheter was placed in either the right or left cephalic vein in all dogs. A standard anesthesia protocol was designed for all dogs and included maropitant (Zoetis; 1 mg/kg, IV), hydromorphone (Baxter; 0.15 mg/kg, IV) in combination with midazolam (Athenex; 0.2 mg/kg, IV), and dexmedetomidine (Dechra Veterinary Product; 2 μg/kg, IV). Propofol (Zoetis; 4 to 6 mg/kg, IV, to effect) was used for induction and general anesthesia was maintained with isoflurane (Covetrus) in 100% oxygen. All dogs received an ultrasound-guided femoral sciatic nerve block using 0.5% bupivacaine (Hospira; 2 mg/kg) performed by a board-certified anesthesiologist. Multiparameter monitors (Mindray Passport; Mindray) were used throughout anesthesia. Perioperative IV fluids were 5 mL/kg/h of Lactated Ringer Solution throughout the entire procedure. If dogs developed intraoperative hypotension (defined as systolic ≤ 80 mmHg or mean arterial pressure ≤ 60 mmHg), an appropriate anesthetic plane was confirmed, and a 10 mL/kg isotonic crystalloid bolus was administered over 20 minutes. If the dog remained hypotensive despite the fluid bolus, glycopyrrolate (Hikma Pharmaceuticals; 0.011 mg/kg) was administered IV. The first dose of cefazolin (WG Critical Care; 22 mg/kg, IV) was given at least 30 minutes prior to surgical incision and then every 90 minutes perioperatively.
Surgical procedure
Dogs enrolled in the study were treated with a stifle arthroscopy and TPLO performed by a board-certified surgeon. All stifle arthroscopies were performed using a 3-portal technique.15 Arthroscopic assessments confirmed cranial cruciate ligament insufficiency in addition to the identification and classification of meniscal tears. Meniscal tears were treated with partial meniscectomy or meniscal release based on the surgeon's preference. After arthroscopy, a TPLO was performed without the use of a jig, which is typically used to proceed with the reduction in size and weight to perform an accurate osteotomy.16 A medial surgical approach to the proximal right tibia was performed. A radial osteotomy was created in the proximal tibia, and the blade size varied and was templated to each patient. The proximal tibial segment was then rotated based on individualized measurements to level the tibial plateau. The tibial osteotomy was stabilized with a 6-hole VOI TPLO plate applied with 5 locking and 1 cortical screw (Veterinary Orthopedic Implants). The surgical site was flushed with sterile saline. Fascia was closed in a combination of cruciate and simple continuous pattern with polydioxanone (PDS; Ethicon), the subcutaneous was closed in a simple continuous pattern with Monocryl (Ethicon), and the skin was apposed in a cruciate pattern with Ethylon (Ethicon). Liposomal bupivacaine (Nocita; Elanco; 5.3 mg/kg) was infused into the incised soft tissues at the time of surgical incision closure. Anesthesia and surgical times varied among patients. Patients were recovered from anesthesia and hospitalized overnight. If the patient showed evidence of vocalization, change in demeanor, severe lameness, or discomfort upon limb palpation or at a walk on overnight evaluations, rescue doses of hydromorphone (Baxter; 0.05 mg/kg, IV) were administered. Dogs were discharged within 24 hours of surgery. Dogs were sent home with a variety of analgesic medications that varied with the length of administration including carprofen (Dechra Veterinary Products; approx 2.2 mg/kg, PO) every 12 hours or meloxicam (Convetrus North America; 0.1 mg/kg, PO) every 24 hours, gabapentin (ScieGen Pharmaceuticals; 10 mg/kg, PO) every 8 to 12 hours, or no medications at all.
Statistical analysis
A Wilcoxon-matched pair-signed rank test was conducted to evaluate the equality of matched pairs of observations testing the null hypothesis that the surgical procedure had no effect on clot lysis at 30% or 45%. An ANOVA was performed to evaluate differences in mean Hct and mean platelets versus the time of measurement. Shapiro-Wilk test was performed to evaluate the normal distribution of Hct percentages, platelet numbers, and fibrinogen concentrations. A Sidak P value adjustment was performed for comparison of time measurements. A Wilcoxon-matched pair-signed rank test was conducted to evaluate matched pairs of fibrinogen concentrations. Viscoelastic data were analyzed for mean, median, SD, minimum and maximum values for clot lysis at 30% and clot lysis at 45% preoperatively and postoperatively, clot time, clot formation time, alpha angle, amplitude at 10 and 20 minutes, and maximum clot firmness. Variance of Hct percentage, platelet numbers, and fibrinogen concentrations were analyzed at the same time points of VCM analysis.
Results
Sample size was calculated based on previously reported veterinary literature.20 Data are provided from 37 dogs with preoperative and postoperative lysis 30% and 45% measurements collected (Tables 2–4). Descriptive statistics including sample size, mean, SD, and range are provided for clot lysis at 30% and 45% by time for preoperative and 14 days postoperatively for a sample size of 37 dogs. The descriptive statistics including number of observations, mean, SD, and range for VCM metrics 14 days postoperatively for a sample size of 37 dogs are listed. Hct percentages, platelet numbers, and fibrinogen concentrations by time of measurement at preoperative, postoperative, 24 hours postoperatively, and 14 days postoperatively are depicted.
Descriptive statistics (number of observations, mean, SD, and range) for clot lysis at 30% and 45% by time of measurement (preoperatively and 2 weeks postoperatively) for observations from 37 patients presenting for stifle arthroscopy and TPLO.
| Clot lysis 30% and 45% recorded pre- and postoperatively | ||||||||
|---|---|---|---|---|---|---|---|---|
| 30% | 45% | |||||||
| Time | n | Mean (%) | SD | Range (%) | n | Mean (%) | SD | Range (%) |
| Preoperatively | 37 | 99.97 | 0.16 | 99–100 | 37 | 99.97 | 0.16 | 99–100 |
| Postoperatively (2 wk) | 37 | 99.86 | 0.67 | 96–100 | 37 | 99.76 | 1.16 | 93–100 |
The values represent the percentage of clot lysis at 30 and 45 minutes after maximum amplitude formation recorded from the viscoelastic coagulation monitoring (VCM). The normal reference intervals (RIs) are clot lysis at 30% (RI, 99 to 100) and clot lysis at 45% (RI, 98 to 100). The mean preoperatively and 2 weeks postoperatively were within normal RIs.
Descriptive statistics (number of observations, mean, SD, and range) followed by normal RIs for clot time (RI, 241 to 470 seconds), clot formation time (RI, 104 to 266 seconds), alpha angle (RI, 43° to 64°), amplitude at 10 (RI, 16 to 30 mm) and 20 minutes (RI, 22 to 38 mm), and maximum clot firmness (RI, 29 to 44 mm) recorded from VCM measurements 2 weeks postoperatively.
| VCM outcomes recorded 2 wk postoperatively | ||||||
|---|---|---|---|---|---|---|
| Clot time (s) | Clot formation time (s) | Alpha angle (°) | Amplitude at 10 min (mm) | Amplitude at 20 min (mm) | Maximum clot firmness (mm) | |
| n | 37 | 37 | 37 | 37 | 37 | 37 |
| Mean | 267.30 | 199.22 | 54.41 | 22.27 | 29.41 | 35.38 |
| SD | 84.26 | 82.81 | 9.32 | 5.19 | 5.63 | 5.81 |
| Range | 82–413 | 108–403 | 36–67 | 13–32 | 19–41 | 26–48 |
The overall mean for each value were all within normal RIs.
Descriptive statistics (number of observations, mean, SD, and range) for Hct percentage (RI, 37% to 61%), platelet (RI, 148 to 484 k/μL), and fibrinogen (RI, 130 to 480 mg/dL) levels by time of measurement preoperatively, immediately postoperatively, and 24 hours postoperatively.
| HCT (%) | Platelets (k/μL) | Fibrinogen (mg/dL) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Time | n | Mean† | SD | Range | n | Mean† | SD | Range | n | Mean | SD | Range |
| Preoperatively | 37 | 49.71a | 5.10 | 38.1–57.2 | 37 | 278.84a | 83.15 | 101–470 | 37 | 213.89 | 81.82 | 78–459 |
| Postoperatively | 36 | 38.82b | 5.62 | 25.9–51.4 | 37 | 216.00b | 58.70 | 67–383 | 35 | 191.63 | 65.93 | 85–395 |
| Postoperatively (24 h) | 34 | 45.23c | 6.04 | 26.9–58.2 | 35 | 228.33b | 68.97 | 126–429 | 35 | 469.4 | 112.36 | 262–754 |
| Postoperatively (2 wk) | 35 | 49.81a | 6.21 | 36.6–63.7 | 36 | 299.37a | 89.52 | 82–516 | 37 | 243.59 | 75.69 | 149–476 |
| P value | < .01 | < .01 | ||||||||||
The means of all values were within normal RIs.
Different superscript letters denote statistically significant mean differences (P < .05) based on an ANOVA test. Different superscript letters denote statistically significant differences in median values (P < .05) based on a Wilcoxon-matched pair-signed rank test.
Clot lysis at 30% (mean, 99.97%) preoperative did not show a significant difference when compared to values 14 days postoperative (mean, 99.86%; Table 2). There was no difference in the distribution of values reported for clot lysis at 45% preoperative (mean, 99.97%) and 14 days postoperatively (mean, 99.76%). When comparing distributions of values for clot lysis at 30% and 45%, observations from patients preoperatively and postoperatively were not significantly different (P > .05). The clot time (mean, 267.3 seconds), clot formation time (mean, 199.22 seconds), alpha angle (mean, 54°), amplitude at 10 minutes (mean, 22.27), amplitude at 20 minutes (mean, 29.41), and the maximum clot firmness (mean, 35.38) were within normal reference intervals at all time points (Table 3). Mean Hct percentages were significantly higher preoperatively (mean, 49.71%) when compared to postoperative (mean, 38.8%) and 24 hours postoperative (mean, 45.23%). When comparing preoperative Hct percentages to 14 days postoperative (49.8%), no significant difference was noted (P < .05). Mean Hct percent values were significantly higher 14 days postoperative than reported 24 hours postoperatively (P < .01). Platelet numbers showed a similar pattern. Mean platelet values were significantly higher preoperative (mean, 278.84 k/μL) than postoperative (mean, 216 k/μL) and 24 hours postoperatively (mean, 228.33 k/μL). Mean platelet values were significantly higher 14 days postoperative in comparison to immediately postoperative and 24 hours postoperative (P < .01). Values immediately postoperative compared to 24 hours postoperative as well as preoperative compared to 14 days postoperative did not show any significant difference (P > .05). The mean fibrinogen concentrations showed significant differences (P < .05) at all time measurements. The highest value was recorded 24 hours postoperative (mean, 469 mg/dL), and the lowest was recorded postoperatively (mean, 191 mg/dL).
Discussion
This study aimed to determine the effects of elective stifle arthroscopy and TPLO on VCM results, Hct percentage, platelet numbers, and fibrinogen concentrations. The study supported the null hypothesis with the results indicating no significant difference among viscoelastic coagulation monitoring and fibrinogen concentrations before and after elective orthopedic procedures.
Humans undergoing orthopedic surgery are at high risk for postoperative hypercoagulation leading to embolism.12 One study reported the prevalence of venous thromboembolism to be as high as 70%, with pulmonary embolism around 3%, and deep venous thrombosis as high as 60% in humans undergoing elective orthopedic surgery.1,2 Furthermore, these patients demonstrated normal coagulation at the time of admission but became significantly hypercoagulable 2 weeks postoperatively and persisted at the 6-week recheck.2 Increased hypercoagulability is seen with the use of tourniquets, bone cement, immobilization, and bed rest.1 Additionally, surgical manipulation of limbs causes endothelial vascular injuries, and thus trauma can result in coagulation dysfunction.1 Trauma-related coagulopathy has been hypothesized to be primarily caused by blood loss, activation and consumption of platelets, and activation of acute phase proteins, but ultimately the exact cause remains unclear. 21 Prophylactic protocols implemented in human medicine include pharmacological and mechanical methods to reduce the risk of hypercoagulable effects of surgery. Despite the presurgical thromboprophylaxis, the occurrence of deep vein thrombosis is still persistently high.2
Research on the effects of orthopedic surgery on coagulation in human medicine has motivated exploration within the veterinary field. If similar results were confirmed, further research into prophylactic treatment preoperatively would be necessary to decrease potential hypercoagulable states. This study determined that TPLO surgery in healthy dogs does not have the same effect on coagulation when compared to their human counterparts. The infrequent occurrence of hypercoagulability leading to thrombotic events after orthopedic surgery in dogs when compared to humans is likely due to surgical technique, physiological differences such as bipedal versus quadrupedal, life span, and the pharmacokinetics/pharmacodynamics of certain drugs.2 Dogs in this study were not exposed to tourniquet use, bed rest, or bone cement, likely reducing their risks of thrombotic events. Additionally, no comorbidities were reported that could contribute to hypercoagulable states.
The accessibility and rapid results of VCM provide an acceptable diagnostic tool for evaluation of coagulation.7 The concentration of clotting factors and platelet function determine the rate of clot formation and are represented by the variables clotting time, clot formation time, and the alpha angle on the VCM. The viscoelastic variable maximum clot formation (MCF) represents clot strength, which is a combination of fibrinogen content and platelet numbers.7 Plasmin-mediated fibrinolysis is measured by the clot breakdown at 30% and 45% after the maximum amplitude (MCF). Clot lysis was evaluated to determine if delay in fibrinolysis was present indicating a hypofibrinolytic state that could promote thrombosis. The mean values reported from VCM values were all within normal reference intervals for this species throughout the entire study and therefore support our null hypothesis.
Hct percentages are known to influence the results of the VCM.7 High Hct percentages can be associated with hypocoagulable states, conversely low percentages can be associated with hypercoagulable trends.7 This study showed a significant decrease in postoperative Hct. These changes are typically due to intraoperative hemorrhaging and IV fluid administration. IV fluid administration can result in hemodilution, which can result in hypercoaguable states.22 In this study, IV fluids were discontinued prior to sample collections postoperatively and as a result did not have a significant effect on VCM results. Furthermore, the initial drop in Hct postoperatively resolved by the 14-day recheck. Stifle arthroscopy and TPLO were associated with an initial decreased Hct percentage but were not associated with a change in VCM results.
Platelet number and function affect the rate of clot formation and can influence the results of VCM.22 Thrombocytosis results in a hypercoagulable state and dogs become at risk of inappropriate clot formation.22 Conversely, thrombocytopenia can lead to hypocoaguable states increasing the risk of hemorrhage.22 Thrombocytopenia is defined as any significant decrease in platelet count of 20% to 30% compared with preoperative baseline values. Decreases in platelet counts within the first 4 days postoperatively are expected due to hemodilution and consumption from surgical hemostasis.23 Evaluation of the effects of orthopedic procedures on platelet number and function is not only important when interpreting VCM results but also for implementing appropriate corrective measures. As expected, the values in this study demonstrated thrombocytopenia immediately postoperatively and 24 hours postoperatively both consistent with the expected trends. However, the mean platelet counts were within normal reported canine reference intervals throughout the entire study. In conclusion, stifle arthroscopy and TPLO have minimal effect on platelet number and function outside of expected surgical trends and therefore did not result in significant changes in VCM values. Platelet clumping was not appreciated on the samples and therefore did not have a significant association with platelet numbers or VCM values. NSAIDs are widely used to provide short and long-term analgesia and anti-inflammatory benefits.24 Since the commonly used nonsteroidal anti-inflammatory medications are cytochrome c oxidase 1 and 2 inhibitors, they are generally considered to have antithrombotic effects.24 The use of these medications was not associated with significant differences on VCM results in this study.
Fibrinogen is the soluble precursor of fibrin and is the key component involved in both primary and secondary hemostasis via the promotion of platelet aggregation and clot formation.25 Additionally, fibrinogen is directly associated with clot strength.25 Low fibrinogen causes decreased clot strength and contributes to an overall hypocoagulable state. Conversely, high fibrinogen strengthens clot formation and yields a hypercoagulable state.26 In human medicine, increased fibrinogen concentration and decreased fibrinolytic activity is common after surgery.2 Due to fibrinogen's acute phase protein activity and its being a key component in clot formation, hyperfibrinogenemia leads to hypercoagulability and is often associated with inflammation or stress as a result of surgery.9 A previous study27 evaluating fibrinolytic pathways in dogs after surgically induced trauma noted postoperative hyperfibrinolysis with a peak of fibrinolysis 24 hours after surgery. The results of this study follow a similar trend with postsurgical hyperfibrinogenemia occurring 24 hours postoperatively. The fibrinogen concentration returned to similar presurgical values by day 14 after surgery. Despite the increase in fibrinogen concentrations, the mean values remained within the reference interval for each time measurement throughout the study. The minimal change in fibrinogen concentrations was not associated with significant changes in VCM results. It is important to evaluate the effects of orthopedic surgery on VCM in addition to fibrinogen to uncover critical links between the disease pathways. Overall, elective stifle arthroscopy and TPLO in healthy dogs were not associated with changes in VCM values or fibrinogen concentrations.
A major limitation of this study was the small sample size. This may not be an accurate representation, as the sample size is typically 10% of the entire population.21 This study was limited to a select sample size of healthy dogs, and further research would be indicated to evaluate the coagulable states of dogs with concurrent comorbidities undergoing elective orthopedic procedures. Additionally, evaluation of VCM and fibrinogen concentrations in dogs undergoing different orthopedic surgeries including orthopedic trauma is warranted.
Acknowledgments
None reported.
Disclosures
The authors have nothing to disclose. No AI-assisted technologies were used in the generation of this manuscript.
Funding
The authors have nothing to disclose.
References
- 1.↑
Mittermayr M, Streif W, Haas T, et al. Hemostatic changes after crystalloid or colloid fluid administration during major orthopedic surgery: the role of fibrinogen administration. Anesth Analg. 2007;105(4):905–917. doi:10.1213/01.ane.0000280481.18570.27
- 2.↑
Kamath S, Lip G. Fibrinogen: biochemistry, epidemiology and determinants. Q J Med. 2003;96(10):711–729. doi:10.1093/qjmed/hcg129
- 3.↑
Prüller F, Münch A, Preininger A, et al. Comparison of functional fibrinogen (FF/CFF) and FIBTEM in surgical patients: a retrospective study. Clin Chem Lab Med. 2016;54(3):453–458.
- 4.↑
Xiong X, Li T, Cheng B. Anemia and formation of deep vein thrombosis before operation in patients with knee osteoarthritis: a cross-sectional study. J Orthop Surg Res. 2023;18(1):3. doi:10.1186/s13018-022-03473-y
- 5.↑
Smith SA, McMichael MA, Gilor S, Galligan AJ, Hoh CM. Correlation of hematocrit, platelet concentration, and plasma coagulation factors with results of thromboelastometry in canine whole blood samples. Am J Vet Res. 2012;73(6):789–798. doi:10.2460/ajvr.73.6.789
- 6.↑
Wiinberg B, Jensen AL, Johansson PI, Rozanski E, Tranholm M, Kristensen AT. Thromboelastographic evaluation of hemostatic function in dogs with disseminated intravascular coagulation. J Vet Int Med. 2008;22(2):357–365. doi:10.1111/j.1939-1676.2008.0058
- 7.↑
Vipond MN, Whawell SA, Thompson JN, Dudley HA. Peritoneal fibrinolytic activity and intra-abdominal adhesions. Lancet. 1990;335(8698):1120–1122. doi:10.1016/0140-6736(90)91125-t
- 8.↑
Chee YL, Greaves M. Role of coagulation testing in predicting bleeding risk. Hematol J. 2003;4(6):373–378. doi:10.1038/sj.thj.6200306
- 9.↑
Hennink I, Peters L, van Geest G, Adamik KN. Evaluation of a viscoelastic coagulation monitoring system (VCM Vet®) and its correlation with thromboelastometry (ROTEM®) in diseased and healthy dogs. Animals (Basel). 2023;13(3):405. doi:10.3390/ani13030405
- 10.↑
McMichael MA, Smith SA. Viscoelastic coagulation testing: technology, applications, and limitations. Vet Clin Pathol. 2011;40(2):140–153. doi:10.1111/j.1939-165X.2011.00302.x
- 11.↑
Flevas DA, Megaloikonomos PD, Dimopoulos L, Mitsiokapa E, Koulouvaris P, Mavrogenis AF. Thromboembolism prophylaxis in orthopaedics: an update. EFORT Open Rev. 2018;3(4):136–148. doi:10.1302/2058-5241.3.170018
- 12.↑
You D, Skeith L, Korley R, et al. Identification of hypercoagulability with thrombelastography in patients with hip fracture receiving thromboprophylaxis. Can J Surg. 2021;64(3):E324–E329. doi:10.1503/cjs.021019
- 13.↑
Donald- Lloyd P, Lee WS, Liu GM. Thromboelastography in elective total hip arthroplasty. World J Orthop. 2021;12(8):555–564. doi:10.5312/wjo.v12.i8.555
- 14.↑
McMichael MA, Goggs R, Smith SA, Wagg C, Warman S, Wiinberg B. Systematic evaluation of evidence on veterinary viscoelastic testing part 1: system comparability. J Vet Emerg Crit Care. 2014;24(1):23–29. doi:10.1111/vec.12143
- 15.↑
Flatland B, Koenigshof AM, Rozanski EA, Goggs R, Wiinberg B. Systematic evaluation of evidence on veterinary viscoelastic testing part 2: sample acquisition and handling. J Vet Emerg Crit Care. 2014;24(1):30–36. doi:10.1111/vec.12142
- 17.
Buriko Y, Silverstein D. Establishment of normal reference intervals in dogs using viscoelastic coagulation monitor (VCM) and validation of the VCM device using thromboelastography (TEG). European Veterinary Emergency and Critical Care Congress, Venice, Italy, June 2018. J Vet Emerg Crit Care. 2018;28:S27.
- 18.↑
Rosati T, Jandrey K, Burges J, et al. Establishment of a reference interval for a novel viscoelastic coagulometer and comparison to thromboelastography in healthy cats. European Veterinary Emergency and Critical Care Congress, Venice, Italy, June 2018. J Vet Emerg Crit Care. 2018;28:S34.
- 19.↑
Goggs R, Brainard B, de Laforcade AM, et al. Partnership on Rotational ViscoElastic Test Standardization (PROVETS): evidence based guidelines on rotational viscoelastic assays in veterinary medicine. J Vet Emerg Crit Care. 2014;24(1):1–22. doi:10.1111/vec.12144
- 20.↑
Nayak BK. Understanding the relevance of sample size calculation. Indian J Ophthalmol. 2010;58(6):469–470. doi:10.4103/0301-4738.71673
- 21.↑
Martini WZ. Coagulation complications following trauma. Mil Med Res. 2016;3:35. doi:10.1186/s40779-016-0105-2
- 22.↑
Wang WH, Lynch AM, Balko JA, Duffy DJ, Robertson JB, Posner LP. Point-of-care viscoelastic coagulation assessment in healthy dogs during the perianesthetic period. BMC Vet Res. 2022;18(1):346. doi:10.1186/s12917-022-03442-x
- 23.↑
Skeith L, Baumann Kreuziger L, Crowther MA, Warkentin TE. A practical approach to evaluating postoperative thrombocytopenia. Blood Adv. 2020;4(4):776–783. doi:10.1182/bloodadvances.2019001414
- 24.↑
Blois SL, Allen DG, Wood RD, Conlon PD. Effects of aspirin, carprofen, deracoxib, and meloxicam on platelet function and systemic prostaglandin concentrations in healthy dogs. Am J Vet Res. 2010;71(3):349–358. doi:10.2460/ajvr.71.3.349
- 25.↑
Marschner CB, Wiinberg B, Tarnow I, et al. The influence of inflammation and hematocrit on clot strength in canine thromboelastographic hypercoagulability. J Vet Emerg Crit Care (San Antonio). 2018;28(1):20–30. doi:10.1111/vec.12675
- 26.↑
Kitrell D, Berkwitt L. Hypercoagulability in dogs: pathophysiology. Compend Contin Educ Vet. 2012;34(4):E1–E5.
- 27.↑
Lanevschi A, Kramer JW, Greene SA, Meyers KM. Fibrinolytic activity in dogs after surgically induced trauma. Am J Vet Res. 1996;57(8):1137–1140.
