|Year : 2022 | Volume
| Issue : 2 | Page : 56-60
Do we need to order prothrombin time/international normalized ratio and activated partial thromboplastin time for children undergoing adenotonsillar surgery?
Tanvir Nazir1, Noor Adam2, Samina Afzal3, Mohamad A Bitar4
1 Department of Otolaryngology Head & Neck Surgery, Al Jalila Children Specialty Hospital, Dubai - Uae 7662, United Arab Emirates
2 Mohammed Bin Rashid University, School of Medicine, Dubai - Uae 7662, United Arab Emirates
3 Department of Hematology/Oncology at Al Jalila Children Specialty Hospital, Dubai - Uae 7662, United Arab Emirates
4 Department of Otolaryngology Head & Neck Surgery, Al Jalila Children Specialty Hospital; Mohammed Bin Rashid University, School of Medicine, Dubai - Uae 7662, United Arab Emirates
|Date of Submission||05-Jan-2022|
|Date of Acceptance||30-Jan-2022|
|Date of Web Publication||28-Jun-2022|
Prof. Mohamad A Bitar
Department of Otolaryngology Head and Neck Surgery, Al Jalila Children's Specialty Hospital, Dubai - Uae 7662
United Arab Emirates
Source of Support: None, Conflict of Interest: None
Objectives: The objectives of this study were to check the prevalence of abnormal preoperative bleeding tests in children planned for adenotonsillar surgery, highlight the workup, and describe the perioperative management for the confirmed cases. Subjects and Methods: This was a retrospective study. We reviewed the age, gender, test values, bleeding tendency, workup of affected patients, and perioperative management. Results: We reviewed 365 patients; 71 patients were found to have abnormal prothrombin time/international normalized ratio (PT/INR), activated partial thromboplastin time (aPTT), or both. There was no history of bleeding tendency. Thirty-six patients had a repeat of the abnormal tests, 17 were still abnormally high (>2 s), 19 normalized or had values decreased to <2 s; 9 had workup, and 6 found to have factor deficiencies. All but eight patients (who lost to follow-up) were operated uneventfully. Conclusion: Patients booked for adenotonsillar surgery need PT/INR and aPTT tested preoperatively. The patients with abnormal results are investigated according to an algorithm. Perioperative planning is essential to avoid intra- and postoperative complications.
Keywords: Adenotonsillar surgery, bleeding tests, preoperative
|How to cite this article:|
Nazir T, Adam N, Afzal S, Bitar MA. Do we need to order prothrombin time/international normalized ratio and activated partial thromboplastin time for children undergoing adenotonsillar surgery?. Saudi J Otorhinolaryngol Head Neck Surg 2022;24:56-60
|How to cite this URL:|
Nazir T, Adam N, Afzal S, Bitar MA. Do we need to order prothrombin time/international normalized ratio and activated partial thromboplastin time for children undergoing adenotonsillar surgery?. Saudi J Otorhinolaryngol Head Neck Surg [serial online] 2022 [cited 2022 Dec 5];24:56-60. Available from: https://www.sjohns.org/text.asp?2022/24/2/56/348716
| Introduction|| |
Adenotonsillar surgery is one of the most common pediatric surgical procedures performed worldwide. Some surgeons rely mainly on history to suspect a bleeding tendency, while others order routinely prothrombin time (PT), international normalized ratio (INR), and activated partial thromboplastin time (aPTT) preoperatively. The history of bleeding tendency in children is often limited as most may not have had any previous surgical procedure or major injury; it often relies on the presence of easy bruisability or a positive family bleeding history. History can also be limited due to the lack of accurate parents' observation or memory.
The literature is divided regarding this issue. Some studies denied their positive predictive value and recommended performing these tests only in selective cases.,, While others demonstrated a positive predictive value for a risk of postoperative bleeding, with some focusing on the importance of ordering these tests to identify patients with newly diagnosed bleeding disorder.,,
We, at our department, order routinely PT/INR and aPTT as part of the preoperative workup on all patients booked for tonsillar and/or adenoidal surgery. In our practice, we have noticed a relatively high prevalence of elevated PT/INR, aPTT, or both among our patients. Although most normalized upon repeating them (once or twice), a small group of patients were eventually diagnosed with factors deficiency, which was alarming to us, as these were newly diagnosed patients.
To have a closer view on this problem, we decided to conduct an observational cross-sectional study of our patients to check the prevalence of abnormal preoperative bleeding tests in children planned for tonsillar and/or adenoid surgery and highlight the workup and perioperative measures needed for the identified patients.
| Subjects and Methods|| |
We conducted an observational cross-sectional study of the children scheduled for tonsillar and/or adenoidal surgery, who were seen between February 2017 and March 2019. We obtained IRB approval to conduct this study. We reviewed the age and gender of the enrolled patients, any history of bleeding tendency, recurrent infections, or recent infection prior to surgery and the performed tests' values. We also reviewed the occurrence of any intraoperative and postoperative bleeding. We analyzed the workup of the affected patients as well as the perioperative management of those with confirmed bleeding disorder.
The variables of the study were recorded on Microsoft Excel sheet and then transformed to the Statistical Package for the Social Sciences (SPSS), version 24, (SPSS inc., Chicago, IL, USA). for analysis. For the prevalence of abnormal bleeding tests, a descriptive analysis was used to measure frequencies and percentages (%), while Chi-squared test was performed to test a relationship between the different variables. The alpha value of P ≤ 0.05 was chosen to determine statistical significance.
| Results|| |
We reviewed 365 patients (M/F, 214/151; median age, 4.69 years; range, 1.3–16.7 years); 71 of them were found to have abnormal PT/INR, aPTT, or both [Table 1]. None had a history of personal bleeding tendency; however, one had a positive family history of bleeding tendency. There was no significant effect of age, gender, a history of recurrent upper respiratory tract infections, or a history of a recent infection prior to the test on the likelihood of getting an abnormal preoperative bleeding test [Table 2].
|Table 2: Relation of various variables on the likelihood of getting an abnormal preoperative bleeding test|
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Those with values within <2 s of the upper normal range were cleared (in consultation with the hematologist) if history was negative or surgery was only for the adenoids. Thirty-six patients had a repeat of the abnormal tests: 17 were still abnormally high (>2 s). Nine patients had a workup; six were found to have confirmed bleeding disorder due to factors deficiencies (namely Von Willebrand disease and Factor VII deficiency) [Table 1].
The type of workup depended on what test was persistently abnormal and thus the differential diagnosis [Table 1] and [Table 3].
|Table 3: Differential diagnosis of persistent abnormal preoperative bleeding tests, workup, and management options|
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Three hundred and fifty-nine patients (6 were lost to follow-up) were operated uneventfully. Three patients reported self-limiting postoperative secondary bleeding (0.84%). The patients with confirmed bleeding dyscrasias were operated under the supervision of our hematology team; management options are included in [Table 3].
| Discussion|| |
The controversy regarding whether to routinely order PT/INR and aPTT preoperatively or not stems from the contradictory results published in the literature and the way these tests were looked at. The main reason behind that is many focused only on the positive predictive value of these tests to justify using them on all surgical patients or not.
Howells et al. (West Virginia 1997) reviewed the predictive value of preoperative PT and aPTT in 339 patients undergoing tonsillectomy; 39 had prolonged PT/INR or aPTT and 30 had borderline elevations and did not need to repeat the tests. One patient from this group experienced postoperative hemorrhage. The remaining nine patients had the tests repeated; 3 normalized, 3 remained prolonged but underwent tonsillectomy with no intervention, and 3 received hematology consultations. The latter were found to have lupus coagulopathy, Hageman factor deficiency, and the third was cleared for surgery with no definite diagnosis. None of these three patients had episodes of postoperative bleeding. Howells et al. concluded that there is no need for routine screening and these tests should be only done in selective cases.
In agreement with them, Zwack GC and Derkay CS (Norfolk 1997) also looked at the predictive value of PT/INR and aPTT, which was found to be low and therefore did not recommend routine screening for all patients.
In a meta-analysis on postoperative bleeding, Krishna P and Lee D (Illinois 2001) found that 3.3% of patients with normal coagulation studies vs. 8.7% of patients with abnormal studies, had postoperative bleeding, which was not statistically significant, to justify routine testing of the patients.
On the other hand, other authors demonstrated a useful positive predictive value of these tests and supported the importance of ordering them preoperatively. Tami et al. (Virginia 1987) reviewed 775 cases and found that postoperative bleeders (2.7%) were more likely to have abnormal preoperative clotting studies, reflecting their importance. Kang et al. (New York 1994) found that an initially abnormal coagulation profile may identify those more likely to bleed after surgery (22.6% vs. 5.5%). They went a bit further, and they noticed that even after normalization of the values after retesting, the affected patients still showed a higher rate (×4) of postoperative bleeding. They also stressed an important point regarding the newly diagnosed patients with coagulopathy, which was 0.57% of total studied group or 25.9% of the 27 patients with initial abnormal laboratory values.
On the same line, Koshkareva et al. (Pittsburg 2012) reviewed 875 patients and found that the incidence of bleeding was significantly higher in patients with abnormal preoperative hematologic screening (7.1%) vs. normal (2.9%). Not only that but they also found that 10 out of 14 patients with coagulopathy had no personal or family history of abnormal bleeding.
Regardless if the preoperative PT/INR and aPTT can predict postoperative bleeding, we should keep in mind that there are many factors other than coagulopathy that affect the rate of intra- or postoperative bleeding. These can include the surgical tool we are using (cold steel, cautery, laser, microdebrider, coblator,…), the surgical technique we are following (extracapsular vs. intracapsular), the surgical experience of the operator (trainee vs. consultant), the practice of ensuring good intraoperative hemostasis, the use of etamsylate or tranexamic acid intraoperatively and sometimes postoperatively, and the presence of any associated medical conditions (diabetes, immunodeficiency.,).
Looking only at the positive predictive value of PT/INR and aPTT underestimates and overlooks the other contributing or causative factors of intraoperative and postoperative bleeding. However, omitting these tests can increase the risk of missing a bleeding disorder in a child and exposing the child to unnecessary danger during the planned elective surgery or any future surgical procedures.
Our intial screening testing revealed abnormal results in 19.4% of the patients. On retesting in 1-2 weeks, only 4.6% had persistent abnormal results. Eventually, 1.1% were diagnosed (newly) with abnormal clotting profile.
One may argue that this is a small percentage (11/1000) and wonder if that is worth it. Well, we should not forget that we initially started with a higher percentage and we do not know which one of them will actually have abnormal coagulopathy. Most of the cases will normalize as the abnormality is commonly caused by antibodies caused by a recent viral infection, but again, it is impossible to know a priori who is false positive and who is truly positive from one test performed. These are elective procedures, and there is no justification for taking unnecessary risk. If we look at the whole process, the chance for discovering a true coagulation factors abnormality after an initial abnormal screening test is 5.6%, which is not a small number.
Both PT/INR and aPTT test the coagulation pathway and measure the time it takes for blood to clot. There are three pathways for coagulation: extrinsic, intrinsic, and common. PT measures the integrity of the extrinsic and common pathway, while aPTT measures the integrity of the intrinsic and common pathway. Prolonged PT/INR or aPTT has been associated with a higher risk of bleeding, and therefore, not screening for them represents a high risk.,
As the prevalence of discovered abnormalities when performing preoperative PT/INR and aPTT varies among countries and centers, we searched for regional reports.
Bitar et al. (Beirut 2019) reviewed 1269 patients and found abnormal screening results in 35 of them (2.8%), which is much lower than our prevalence rate of 19.4%. However, only 18 patients were eventually diagnosed with coagulopathy, resulting in a prevalence of 1.4% which is close to our finding. It is worth noting that half of the patients with confirmed coagulopathy had a family history of bleeding tendency, something that was absent in our series. The chance of finding a true abnormality after an initial abnormal screening was 51.4%, a much higher figure than the one we encountered. This may be explained by the presence of a significant number of patients among the group with initial abnormal tests, who had a positive family history of bleeding tendency in their series.
In another study, Alzahrani et al. (Riyadh 2019) reviewed 2078 cases undergoing various surgeries (not only pertinent to ear nose and throat); 77 cases had abnormal coagulation results (3.7%) which eventually dropped to 7 patients with abnormal factor assay (0.3%). Their calculated chance of true abnormality after initial abnormal screening was 9% which is close to our findings. None of their patients had postoperative bleeding. The only pitfall in this study is that they included mixed surgery types from different specialties; however, the findings are still valid regarding discovering newly diagnosed coagulation disorders in the preoperative patients.
In our opinion, it is important to screen patients undergoing adenotonsillar surgery by ordering preoperative PT/INR and aPTT, regardless of the personal and family history of bleeding tendencies. We believe that their value is in newly diagnosing bleeding tendency in patients. We are suggesting an algorithm that can be useful in case abnormal values are encountered in the initial preoperative screening [Figure 1]. Patients with confirmed diagnosis can be operated on using a suggested hematological perioperative plan.
|Figure 1: Algorithm to follow when encountering abnormal values in the initial preoperative screening|
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]