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Relationship between clinical history, coagulation tests, and perioperative bleeding during tonsillectomies in pediatrics
Original Contributions Relationship Between Clinical History, Coagulation Tests, and Perioperative Bleeding During Tonsillectomies in Pediatrics Paule Gabriel, MD,* Xavier Mazoit, MD, PhD,* Claude Ecoffey, MD† Departements of Anesthesiology and Surgical Intensive Care, Centre Hospitalier de Lonjumeau, Centre Hospitalier Universitaire du Kremlin-Biceˆtre, Universite´ Paris Sud, and Centre Hospitalier Universitaire de Rennes, Universite´ Rennes 1, France
*Staff Anesthesiologist *Association des Anesthe´sistes-Re´animateurs Pe´diatres d’Expression Franc¸aise, i.e., Association of French Language Pediatric Anesthesia. Address reprint requests to: Professeur Claude Ecoffey, Service d’Anesthe´sie-Re´animation Chirurgicale 2, Hoˆpital Pontchaillou, 2 rue Henri Le Guilloux, 35033 Rennes ce´dex 9, France. E-mail: cEcoffey.rennes@ invivo.edu Presented in part at the annual meeting of the American Society of Anesthesiologists, Orlando, Florida, October 17–21, 1998. Received for publication October 21, 1999; revised manuscript accepted for publication March 30, 2000.
Study Objective: To determine the value of clinical history and preoperative coagulation tests. Design: Prospective, multicenter clinical investigation. Setting: Twenty-four centers over a one-year period. Patients: 1,706 children scheduled for tonsillectomy. In 1,479 out of 1,706 children, studied age was ranged from 9 months to 15 years. Indications for surgery were tonsillar infection 54%, sleep apnea 33%, or both 13%. Surgical dissection was performed in 1,284 cases (88%) and sluder technique in 172 cases (12%). Measurements and Main Results: Clinical history of bleeding, preoperative coagulation tests, and perioperative bleeding were recorded. Clinical history of bleeding was positive in 13 patients; clinical history cannot predict abnormal coagulation tests. Coagulation tests were abnormal in 57 children (4%). Only 8 patients had disease-induced bleeding; five children had a preoperative correction of the deficiency in factor of coagulation or received desmopressin acetate prior to surgery in the case of von Willebrand’s disease. Bleeding that occurred during the intraoperative period was assessed as abnormal by the surgeon in 101 children (7%) and during the postoperative period in 50 children (3%). Univariate analysis showed a relationship between intraoperative bleeding and age (p ⬍ 0.001), sluder technique (p ⬍ 0.001), and abnormal preoperative coagulation tests (p ⬍ 0.05). Multivariate analysis showed the probability that bleeding was linked to the center where the surgery took place, the technique used, i.e., sluder technique, and the child’s age, i.e., the older children. Conclusions: Preoperative assessment based on the history of bleeding cannot predict abnormal laboratory tests. Neither the history of bleeding or laboratory tests can predict postoperative bleeding. © 2000 by Elsevier Science Inc. Keywords: Anesthesia; pediatrics; ENT surgery; tonsillectomy; coagulation tests
†Chef de Service Journal of Clinical Anesthesia 12:288 –291, 2000 © 2000 Elsevier Science Inc. All rights reserved. 655 Avenue of the Americas, New York, NY 10010
0952-8180/00/$–see front matter PII S0952-8180(00)00164-1
Coagulation and pediatric tonsillectomy: Gabriel et al.
Introduction The incidence of posttonsillectomy hemorrhage has decreased but is still reported to be 1% to 8% of cases.1– 8 It is commonly accepted that this hemorrhage is primarily related to the degree of surgical trauma and the effectiveness of local hemostasis. However, local infection, lack of previously organized clots, local trauma from food and unrecognized acquired or hereditary hemostatic defects, also have been cited as possible causes of peritonsillectomy hemorrhage.5 Preoperative coagulation analysis is commonly used to identify patients who may experience peritonsillectomy hemorrhage,9 because in the pediatric patient the reliability of the history may be poor and there may not have been any previous hemostatic challenge. In addition to these issues, routine screening may serve as a defensive posture for some surgeons in today’s litigious medical environment. Nonetheless, tonsillectomy with or without adenoidectomy is the most common major surgical procedure performed in the pediatric patient. Even though the cost of prothrombin time (PT) and activated partial thromboplastin (aPTT) is low the overall cost is significant. Therefore, some authors have proposed to test only the children with a personal and family history of bleeding.1,10 The multicenter prospective study (Appendix) was performed by the ADARPEF’s group* to determine whether preoperative coagulation screening, i.e., clinical history analysis and laboratory tests, are valuable in predicting bleeding in patients, and to study the predictive value of clinical history to detect abnormal laboratory tests in children scheduled for tonsillectomies.
Materials and Methods From January 1996 to December 1996, 24 centers were enrolled in a prospective study; 1,706 children were studied. For each child, the age, outpatient or inpatient procedure, indication of tonsillectomy, i.e., tonsillar infection or sleep apnea, use of endotracheal tube or laryngeal mask airway (LMA), technique of surgery, i.e., sharp and blunt dissection of the superior pole and snare excision of the inferior pole with electrocautery or sluder technique, were noted. The history of bleeding disorders was evaluated by Watson-William.11. The preoperative coagulation screening was as follows: aPTT with normal values between 32 and 46 seconds, PT with a normal range between 11.5 and 13.5 seconds, bleeding time (BT) with normal values beween 2 and 5 minutes, and platelet count considered abnormal at less than 150,000 platelets per millimeter cubed (mm3). The coagulation tests were repeated for the patients with abnormal preoperative values. A second abnormal result was defined as a “persistently abnormal” result, and further evaluation was performed. Abnormal intraoperative bleeding was assessed by surgeon (yes or no response) and postoperative bleeding included immediate and delayed hemorrhage during the first 24 hours requiring admission to hospital and/or a return to the operating room (OR). Values are expressed as means ⫾ SD. Chi 2
Table 1. Relationship Between Clinical History of Bleeding and Coagulation Tests (p ⬍ 0.479).
Clinical History
Normal Coagulation Tests
Abnormal Coagulation Tests
12 1389
1 56
Positive (n ⫽ 13) Negative (n ⫽ 1445)
test, Student’s t-test, and logistic regression were used as appropriate.
Results Six of the 24 centers were excluded due to the small number of patients enrolled (less than 1.5% of total patients), i.e., 86 patients. In addition, 141 children were excluded from the study due to lack of assessment of clinical history of bleeding and/or coagulation tests. These children were similar to the patients studied for age, indication of surgery, and technique of surgery. Finally, 1,479 of 1,706 children were included in the study. Mean age was 5.7 ⫾ 2.8 years (range 9 months–15 yrs). Mean weight was 22 ⫾ 11 kg (range 8 kg to 93 kg). Two hundred eighty children (19%) were outpatient and 1,198 (81%) were inpatient. Indication for surgery was tonsillar infection (783 children, 54%), sleep apnea (478 children, 33%), or both (195 children, 13%). An endotracheal tube was used in 1,447 children and LMA in 18 children. Surgical dissection was performed in 1,284 cases (88%), and sluder technique in 172 cases (12%). Clinical history of bleeding was positive in 13 patients (0.9%). Table 1 shows that clinical history cannot predict abnormal coagulation tests. In addition, 1,406 coagulation tests (96%) were normal, whereas 57 (4%) were abnormal (Table 2). Only 8 patients had disease-induced bleeding: four von Willebrand’s disease, one patient had deficiency in factor VIII, two had deficiency in factor XI, and one had deficiency in factor VII. Five children had a preoperative correction of the deficiency in factor of coagulation or
Table 2. Abnormal Preoperative Coagulation Screening Tests
Abnormal aPTT (n ⫽ 48) PT (n ⫽ 3) Bleeding time (n ⫽ 9) Platelet counts (n ⫽ 1)
48* 3† 9‡ 1
Normal After New Assessment
No Control
15 2 1
6 3
aPTT ⫽ activated partial thromboplastin time; PT ⫽ prothrombin time. *Including 6 children with disease inducing bleeding. †Including one child with low factor VII. ‡Including two children with disease-induced bleeding. J. Clin. Anesth., vol. 12, June 2000
289
Original Contributions
Table 3. Univariate Analysis of Risk Factors for Intraoperative and Postoperative Bleeding
Age (yrs) Sepsis (n) Obstruction (n) Sluder technique (n) Positive clinical history (n) Abnormal coagulation tests*
n ⴝ 1,479
Intraoperative Bleeding (n ⴝ 101)
Postoperative Bleeding (n ⴝ 50)
5.7 ⫾ 2.8 960 675 172 13 52
6.7 ⫾ 3.0 (p ⫽ 0.001) 39 (p ⫽ 0.058) 39 (p ⫽ 0.182) 25 (p ⬍ 0.001) 2 (p ⫽ 0.222) 7 (p ⬍ 0.05)
5.8 ⫾ 3.0 (p ⫽ 0.711) 33 (p ⫽ 0.219) 22 (p ⫽ 0.662) 9 (p ⫽ 0.090) 1 (p ⫽ 0.123) 2 (p ⬍ 0.869)
*Patients with abnormal coagulation tests and no preoperative correction.
received desmopressin acetate (DDAVP) prior to surgery in the case of von Willebrand’s disease. No surgery was cancelled due to abnormal tests. Bleeding that occurred during the intraoperative period was assessed as abnormal by the surgeon in 101 children (7%), and during postoperative period in 50 children (3%). The bleeding children did not receive transfusions of packed red blood cells of fresh frozen plasma; 25 children with postoperative bleeding required reoperation. Univariate analysis showed a relationship between intraoperative bleeding and age (p ⬍ 0.001), sluder technique (p ⬍ 0.001), and abnormal preoperative coagulation tests (p ⬎ 0.05; Table 3). Multivariate analysis showed the probability to bleed was linked to the center, the technique, i.e., sluder technique, and the child’s age, i.e., the older child.
Discussion This study provides further evidence that routine screening tests are not completely helpful in prospectively identifying children who will have excessive bleeding associated with tonsillectomy. In addition, preoperative clinical history of coagulation cannot detect abnormalities in coagulation tests, probably because 30% of tests were normal after new assessment. Finally, age and surgical technique are the sole predicting factors of perioperative bleeding during tonsillectomy. In this study, the incidence of intraoperative bleeding was 7%, and the incidence of postoperative bleeding was 3%. This finding is in accordance with the literature (range of bleeding incidence from 1% to 8%). However, the 7% value in this study may be overestimated due to the subjective assessment by the surgeon, i.e., abnormal bleeding yes or no response sought. In addition, in this study only immediate postoperative bleeding was recorded, with surgical reoperation in half of the patients. Coagulation tests should be performed only in patients with positive history of bleeding on physical examination, which is the recommendation of the American Academy of Otolaryngology—Head and Neck surgery. This recommendation is supported by prospective and retrospective studies, which have concluded that in symptomatic patients, screening coagulation tests are of questionable value and result in a large number of false-positive results.1,8 However, the new information resulting from this study is the lack of significant relationship between clinical history of bleeding and abnormal laboratory tests. 290
J. Clin. Anesth., vol. 12, June 2000
Nonetheless, the low incidence of abnormal laboratory tests can explain this lack of relationship with clinical history of bleeding. In addition, a frequent screening abnormality in asymptomatic patients who undergo perioperative testing is prolongation of the aPTT, which is usually caused by a lupus anticoagulant.12 The lupus anticoagulant is an antibody against phospholipids that interferes with phospholipid-dependent clotting tests, such as the aPTT. The antibody that can be induced by infections is not associated with clinical history of bleeding or an increased risk for bleeding. Futhermore, screening tests such as the aPTT are often normal in patients with a mild bleeding history caused by von Willebrand’s disease.13 The positive specialized tests for the diagnosis of von Willebrand’s disease are performed because of the positive history, regardless of the results of the aPTT. In conclusion, the abnormal aPTT and the PT cannot predict postoperative bleeding. Despite the absence of significant relationship between abnormal bleeding clinical history and abnormal coagulation tests, the aPTT and the PT should not be routinely performed in children who are to undergo tonsillectomies unless they have a history suggestive of bleeding disorder. Indeed, a careful preoperative assessment based on the history and the laboratory tests is unlikely to reduce the incidence of postoperative bleeding that is caused by factors other than disorders of hemostasis, such as lack of efficient electrocautery of an artery in tonsil area, which is the main etiology of postoperative bleeding following tonsillectomies.
Appendix The following hospitals participated in the study: Centre Hospitalier Universitaire Angers, Angers, France; Centre Hospitalier Aulnay-sous-Bois, Aulnay-sous-Bois, Paris, France; Centre Hospitalier Universitaire Besancon, Besancon, France; Centre Hospitalier Universitaire Bordeaux, Bordeaux, Pessac, France; Centre Hospitalier Universitaire Caen, Caen, France; Centre Hospitalier Cre´teil Intercommunal, Cre´teil, France; Centre Hospitalier Universitaire Kremlin-Bicetre, Le Kremlin-Bicetre, France; Centre Hospitalier Saint-Pierre (La Re´union); Centre Hospitalier La Rochelle, La Rochelle, France; Centre Hospitalier Longjumeau, Conjumeau, France; Universite´ Catholique Louvain, Louvain, Belgium; Centre Hospitalier Universitaire Montpellier, Montpellier, France; Centre Hospitalier Universitaire Nancy, Nancy, France; Centre Hospitalier
Coagulation and pediatric tonsillectomy: Gabriel et al.
Universitaire Nantes, Nantes, France; Hoˆpital Lenval Nice, Nice, France; Centre Hospitalier Universitaire Nimes, Nimes, France; Centre Hospitalier Orle`ans, Orle`ans, France; Centre Hospitalier Orthez, Orthez, France; Centre Hospitalier Universitaire Poitiers, Poitiers, France; Centre Hospitalier Universitaire Rennes, Rennes, France; Centre Hospitalier Universitaire St. Vincent de Paul Paris, Paris, France; Centre Hospitalier Universitaire Toulouse, Toulouse, France; Centre Hospitalier Universitaire Tours, Tours, France; Centre Hospitalier Universitaire Trousseau, Paris, France.
References 1. Burk CD, Miller L, Handler SD, Cohen AR: Preoperative history and coagulation screening in children undergoing tonsillectomy. Pediatrics 1990;69:691–5. 2. Kendrick D, Gibbin K: An audit of the complications in pediatric tonsillectomy, adenoidectomy and adenotonsillectomy. Clin Otolaryngol. 1993;18:115–7. 3. Truy E, Merad F, Robin P, Fantino B, Morgon A: Failures in outpatient tonsillectomy policy in children: a retrospective study in 311 children. Int J Pediatr Otorhinolaryngol. 1994;29:33– 42. 4. Kang J, Brodsky L, Danziger I, Volk M, Stanievich J: Coagulation profiles as a predictor for post-tonsillectomy and adenoid-
5. 6.
7.
8.
9. 10.
11. 12.
13.
ectomy (T⫹A) hemorrhage. Int J Pediatr Otorhinolaryngol 1994; 28:157– 65. Myssiorek D, Alvi A: Post-tonsillectomy hemorrhage: an assessment of risk factors. Int J Pediatr Otorhinolaryngol 1996;37:35– 43. Howells RC, Wax M, Ramadan H: Value of preoperative prothrombin time/partial thromboplastin time as a predictor of postoperative hemorrhage in pediatric patients undergoing tonsillectomy. Otolaryngol Head Neck Surg 1997;117:628 –32. Zwack KG, Derkay CS: The utility of preoperative hemostatic assessment in adenotonsillectomy. Int J Pediatr Otorhinolaryngol 1997;39:67–76. Irani D, Berkowitz R: Management of secondary hemorrhage following pediatric adenotonsillectomy. Int J Pediatr Otorhinolaryngol 1997;40:115–24. Borzotta AP, Keeling MM: Value of the preoperative history as an indicator of hemostatic disorders. Ann Surg 1984;200:648 –52. Manning SC, Beste D, McBride T, Golberg A: An assessment of preoperative coagulation screening for tonsillectomy and adenoidectomy. Int J Pediatr Otorhinolaryngol 1987;13:237– 44. Watson-William EJ: Preoperative evaluation of hemostatic competence. Med Clin No Am, 1979;63:1165– 89. Kitchens CS: Prolonged activated partial thromboplastin time of unknown etiology: a prospective study of 100 consecutive cases referred for consultation. Am J Clin Pathol 1988;27:38 – 45. Perry JJ, Alving BM: Von Willebrand’s disease. Am Fam Physician 1990;41:219 –24.
J. Clin. Anesth., vol. 12, June 2000
291
*Staff Anesthesiologist *Association des Anesthe´sistes-Re´animateurs Pe´diatres d’Expression Franc¸aise, i.e., Association of French Language Pediatric Anesthesia. Address reprint requests to: Professeur Claude Ecoffey, Service d’Anesthe´sie-Re´animation Chirurgicale 2, Hoˆpital Pontchaillou, 2 rue Henri Le Guilloux, 35033 Rennes ce´dex 9, France. E-mail: cEcoffey.rennes@ invivo.edu Presented in part at the annual meeting of the American Society of Anesthesiologists, Orlando, Florida, October 17–21, 1998. Received for publication October 21, 1999; revised manuscript accepted for publication March 30, 2000.
Study Objective: To determine the value of clinical history and preoperative coagulation tests. Design: Prospective, multicenter clinical investigation. Setting: Twenty-four centers over a one-year period. Patients: 1,706 children scheduled for tonsillectomy. In 1,479 out of 1,706 children, studied age was ranged from 9 months to 15 years. Indications for surgery were tonsillar infection 54%, sleep apnea 33%, or both 13%. Surgical dissection was performed in 1,284 cases (88%) and sluder technique in 172 cases (12%). Measurements and Main Results: Clinical history of bleeding, preoperative coagulation tests, and perioperative bleeding were recorded. Clinical history of bleeding was positive in 13 patients; clinical history cannot predict abnormal coagulation tests. Coagulation tests were abnormal in 57 children (4%). Only 8 patients had disease-induced bleeding; five children had a preoperative correction of the deficiency in factor of coagulation or received desmopressin acetate prior to surgery in the case of von Willebrand’s disease. Bleeding that occurred during the intraoperative period was assessed as abnormal by the surgeon in 101 children (7%) and during the postoperative period in 50 children (3%). Univariate analysis showed a relationship between intraoperative bleeding and age (p ⬍ 0.001), sluder technique (p ⬍ 0.001), and abnormal preoperative coagulation tests (p ⬍ 0.05). Multivariate analysis showed the probability that bleeding was linked to the center where the surgery took place, the technique used, i.e., sluder technique, and the child’s age, i.e., the older children. Conclusions: Preoperative assessment based on the history of bleeding cannot predict abnormal laboratory tests. Neither the history of bleeding or laboratory tests can predict postoperative bleeding. © 2000 by Elsevier Science Inc. Keywords: Anesthesia; pediatrics; ENT surgery; tonsillectomy; coagulation tests
†Chef de Service Journal of Clinical Anesthesia 12:288 –291, 2000 © 2000 Elsevier Science Inc. All rights reserved. 655 Avenue of the Americas, New York, NY 10010
0952-8180/00/$–see front matter PII S0952-8180(00)00164-1
Coagulation and pediatric tonsillectomy: Gabriel et al.
Introduction The incidence of posttonsillectomy hemorrhage has decreased but is still reported to be 1% to 8% of cases.1– 8 It is commonly accepted that this hemorrhage is primarily related to the degree of surgical trauma and the effectiveness of local hemostasis. However, local infection, lack of previously organized clots, local trauma from food and unrecognized acquired or hereditary hemostatic defects, also have been cited as possible causes of peritonsillectomy hemorrhage.5 Preoperative coagulation analysis is commonly used to identify patients who may experience peritonsillectomy hemorrhage,9 because in the pediatric patient the reliability of the history may be poor and there may not have been any previous hemostatic challenge. In addition to these issues, routine screening may serve as a defensive posture for some surgeons in today’s litigious medical environment. Nonetheless, tonsillectomy with or without adenoidectomy is the most common major surgical procedure performed in the pediatric patient. Even though the cost of prothrombin time (PT) and activated partial thromboplastin (aPTT) is low the overall cost is significant. Therefore, some authors have proposed to test only the children with a personal and family history of bleeding.1,10 The multicenter prospective study (Appendix) was performed by the ADARPEF’s group* to determine whether preoperative coagulation screening, i.e., clinical history analysis and laboratory tests, are valuable in predicting bleeding in patients, and to study the predictive value of clinical history to detect abnormal laboratory tests in children scheduled for tonsillectomies.
Materials and Methods From January 1996 to December 1996, 24 centers were enrolled in a prospective study; 1,706 children were studied. For each child, the age, outpatient or inpatient procedure, indication of tonsillectomy, i.e., tonsillar infection or sleep apnea, use of endotracheal tube or laryngeal mask airway (LMA), technique of surgery, i.e., sharp and blunt dissection of the superior pole and snare excision of the inferior pole with electrocautery or sluder technique, were noted. The history of bleeding disorders was evaluated by Watson-William.11. The preoperative coagulation screening was as follows: aPTT with normal values between 32 and 46 seconds, PT with a normal range between 11.5 and 13.5 seconds, bleeding time (BT) with normal values beween 2 and 5 minutes, and platelet count considered abnormal at less than 150,000 platelets per millimeter cubed (mm3). The coagulation tests were repeated for the patients with abnormal preoperative values. A second abnormal result was defined as a “persistently abnormal” result, and further evaluation was performed. Abnormal intraoperative bleeding was assessed by surgeon (yes or no response) and postoperative bleeding included immediate and delayed hemorrhage during the first 24 hours requiring admission to hospital and/or a return to the operating room (OR). Values are expressed as means ⫾ SD. Chi 2
Table 1. Relationship Between Clinical History of Bleeding and Coagulation Tests (p ⬍ 0.479).
Clinical History
Normal Coagulation Tests
Abnormal Coagulation Tests
12 1389
1 56
Positive (n ⫽ 13) Negative (n ⫽ 1445)
test, Student’s t-test, and logistic regression were used as appropriate.
Results Six of the 24 centers were excluded due to the small number of patients enrolled (less than 1.5% of total patients), i.e., 86 patients. In addition, 141 children were excluded from the study due to lack of assessment of clinical history of bleeding and/or coagulation tests. These children were similar to the patients studied for age, indication of surgery, and technique of surgery. Finally, 1,479 of 1,706 children were included in the study. Mean age was 5.7 ⫾ 2.8 years (range 9 months–15 yrs). Mean weight was 22 ⫾ 11 kg (range 8 kg to 93 kg). Two hundred eighty children (19%) were outpatient and 1,198 (81%) were inpatient. Indication for surgery was tonsillar infection (783 children, 54%), sleep apnea (478 children, 33%), or both (195 children, 13%). An endotracheal tube was used in 1,447 children and LMA in 18 children. Surgical dissection was performed in 1,284 cases (88%), and sluder technique in 172 cases (12%). Clinical history of bleeding was positive in 13 patients (0.9%). Table 1 shows that clinical history cannot predict abnormal coagulation tests. In addition, 1,406 coagulation tests (96%) were normal, whereas 57 (4%) were abnormal (Table 2). Only 8 patients had disease-induced bleeding: four von Willebrand’s disease, one patient had deficiency in factor VIII, two had deficiency in factor XI, and one had deficiency in factor VII. Five children had a preoperative correction of the deficiency in factor of coagulation or
Table 2. Abnormal Preoperative Coagulation Screening Tests
Abnormal aPTT (n ⫽ 48) PT (n ⫽ 3) Bleeding time (n ⫽ 9) Platelet counts (n ⫽ 1)
48* 3† 9‡ 1
Normal After New Assessment
No Control
15 2 1
6 3
aPTT ⫽ activated partial thromboplastin time; PT ⫽ prothrombin time. *Including 6 children with disease inducing bleeding. †Including one child with low factor VII. ‡Including two children with disease-induced bleeding. J. Clin. Anesth., vol. 12, June 2000
289
Original Contributions
Table 3. Univariate Analysis of Risk Factors for Intraoperative and Postoperative Bleeding
Age (yrs) Sepsis (n) Obstruction (n) Sluder technique (n) Positive clinical history (n) Abnormal coagulation tests*
n ⴝ 1,479
Intraoperative Bleeding (n ⴝ 101)
Postoperative Bleeding (n ⴝ 50)
5.7 ⫾ 2.8 960 675 172 13 52
6.7 ⫾ 3.0 (p ⫽ 0.001) 39 (p ⫽ 0.058) 39 (p ⫽ 0.182) 25 (p ⬍ 0.001) 2 (p ⫽ 0.222) 7 (p ⬍ 0.05)
5.8 ⫾ 3.0 (p ⫽ 0.711) 33 (p ⫽ 0.219) 22 (p ⫽ 0.662) 9 (p ⫽ 0.090) 1 (p ⫽ 0.123) 2 (p ⬍ 0.869)
*Patients with abnormal coagulation tests and no preoperative correction.
received desmopressin acetate (DDAVP) prior to surgery in the case of von Willebrand’s disease. No surgery was cancelled due to abnormal tests. Bleeding that occurred during the intraoperative period was assessed as abnormal by the surgeon in 101 children (7%), and during postoperative period in 50 children (3%). The bleeding children did not receive transfusions of packed red blood cells of fresh frozen plasma; 25 children with postoperative bleeding required reoperation. Univariate analysis showed a relationship between intraoperative bleeding and age (p ⬍ 0.001), sluder technique (p ⬍ 0.001), and abnormal preoperative coagulation tests (p ⬎ 0.05; Table 3). Multivariate analysis showed the probability to bleed was linked to the center, the technique, i.e., sluder technique, and the child’s age, i.e., the older child.
Discussion This study provides further evidence that routine screening tests are not completely helpful in prospectively identifying children who will have excessive bleeding associated with tonsillectomy. In addition, preoperative clinical history of coagulation cannot detect abnormalities in coagulation tests, probably because 30% of tests were normal after new assessment. Finally, age and surgical technique are the sole predicting factors of perioperative bleeding during tonsillectomy. In this study, the incidence of intraoperative bleeding was 7%, and the incidence of postoperative bleeding was 3%. This finding is in accordance with the literature (range of bleeding incidence from 1% to 8%). However, the 7% value in this study may be overestimated due to the subjective assessment by the surgeon, i.e., abnormal bleeding yes or no response sought. In addition, in this study only immediate postoperative bleeding was recorded, with surgical reoperation in half of the patients. Coagulation tests should be performed only in patients with positive history of bleeding on physical examination, which is the recommendation of the American Academy of Otolaryngology—Head and Neck surgery. This recommendation is supported by prospective and retrospective studies, which have concluded that in symptomatic patients, screening coagulation tests are of questionable value and result in a large number of false-positive results.1,8 However, the new information resulting from this study is the lack of significant relationship between clinical history of bleeding and abnormal laboratory tests. 290
J. Clin. Anesth., vol. 12, June 2000
Nonetheless, the low incidence of abnormal laboratory tests can explain this lack of relationship with clinical history of bleeding. In addition, a frequent screening abnormality in asymptomatic patients who undergo perioperative testing is prolongation of the aPTT, which is usually caused by a lupus anticoagulant.12 The lupus anticoagulant is an antibody against phospholipids that interferes with phospholipid-dependent clotting tests, such as the aPTT. The antibody that can be induced by infections is not associated with clinical history of bleeding or an increased risk for bleeding. Futhermore, screening tests such as the aPTT are often normal in patients with a mild bleeding history caused by von Willebrand’s disease.13 The positive specialized tests for the diagnosis of von Willebrand’s disease are performed because of the positive history, regardless of the results of the aPTT. In conclusion, the abnormal aPTT and the PT cannot predict postoperative bleeding. Despite the absence of significant relationship between abnormal bleeding clinical history and abnormal coagulation tests, the aPTT and the PT should not be routinely performed in children who are to undergo tonsillectomies unless they have a history suggestive of bleeding disorder. Indeed, a careful preoperative assessment based on the history and the laboratory tests is unlikely to reduce the incidence of postoperative bleeding that is caused by factors other than disorders of hemostasis, such as lack of efficient electrocautery of an artery in tonsil area, which is the main etiology of postoperative bleeding following tonsillectomies.
Appendix The following hospitals participated in the study: Centre Hospitalier Universitaire Angers, Angers, France; Centre Hospitalier Aulnay-sous-Bois, Aulnay-sous-Bois, Paris, France; Centre Hospitalier Universitaire Besancon, Besancon, France; Centre Hospitalier Universitaire Bordeaux, Bordeaux, Pessac, France; Centre Hospitalier Universitaire Caen, Caen, France; Centre Hospitalier Cre´teil Intercommunal, Cre´teil, France; Centre Hospitalier Universitaire Kremlin-Bicetre, Le Kremlin-Bicetre, France; Centre Hospitalier Saint-Pierre (La Re´union); Centre Hospitalier La Rochelle, La Rochelle, France; Centre Hospitalier Longjumeau, Conjumeau, France; Universite´ Catholique Louvain, Louvain, Belgium; Centre Hospitalier Universitaire Montpellier, Montpellier, France; Centre Hospitalier Universitaire Nancy, Nancy, France; Centre Hospitalier
Coagulation and pediatric tonsillectomy: Gabriel et al.
Universitaire Nantes, Nantes, France; Hoˆpital Lenval Nice, Nice, France; Centre Hospitalier Universitaire Nimes, Nimes, France; Centre Hospitalier Orle`ans, Orle`ans, France; Centre Hospitalier Orthez, Orthez, France; Centre Hospitalier Universitaire Poitiers, Poitiers, France; Centre Hospitalier Universitaire Rennes, Rennes, France; Centre Hospitalier Universitaire St. Vincent de Paul Paris, Paris, France; Centre Hospitalier Universitaire Toulouse, Toulouse, France; Centre Hospitalier Universitaire Tours, Tours, France; Centre Hospitalier Universitaire Trousseau, Paris, France.
References 1. Burk CD, Miller L, Handler SD, Cohen AR: Preoperative history and coagulation screening in children undergoing tonsillectomy. Pediatrics 1990;69:691–5. 2. Kendrick D, Gibbin K: An audit of the complications in pediatric tonsillectomy, adenoidectomy and adenotonsillectomy. Clin Otolaryngol. 1993;18:115–7. 3. Truy E, Merad F, Robin P, Fantino B, Morgon A: Failures in outpatient tonsillectomy policy in children: a retrospective study in 311 children. Int J Pediatr Otorhinolaryngol. 1994;29:33– 42. 4. Kang J, Brodsky L, Danziger I, Volk M, Stanievich J: Coagulation profiles as a predictor for post-tonsillectomy and adenoid-
5. 6.
7.
8.
9. 10.
11. 12.
13.
ectomy (T⫹A) hemorrhage. Int J Pediatr Otorhinolaryngol 1994; 28:157– 65. Myssiorek D, Alvi A: Post-tonsillectomy hemorrhage: an assessment of risk factors. Int J Pediatr Otorhinolaryngol 1996;37:35– 43. Howells RC, Wax M, Ramadan H: Value of preoperative prothrombin time/partial thromboplastin time as a predictor of postoperative hemorrhage in pediatric patients undergoing tonsillectomy. Otolaryngol Head Neck Surg 1997;117:628 –32. Zwack KG, Derkay CS: The utility of preoperative hemostatic assessment in adenotonsillectomy. Int J Pediatr Otorhinolaryngol 1997;39:67–76. Irani D, Berkowitz R: Management of secondary hemorrhage following pediatric adenotonsillectomy. Int J Pediatr Otorhinolaryngol 1997;40:115–24. Borzotta AP, Keeling MM: Value of the preoperative history as an indicator of hemostatic disorders. Ann Surg 1984;200:648 –52. Manning SC, Beste D, McBride T, Golberg A: An assessment of preoperative coagulation screening for tonsillectomy and adenoidectomy. Int J Pediatr Otorhinolaryngol 1987;13:237– 44. Watson-William EJ: Preoperative evaluation of hemostatic competence. Med Clin No Am, 1979;63:1165– 89. Kitchens CS: Prolonged activated partial thromboplastin time of unknown etiology: a prospective study of 100 consecutive cases referred for consultation. Am J Clin Pathol 1988;27:38 – 45. Perry JJ, Alving BM: Von Willebrand’s disease. Am Fam Physician 1990;41:219 –24.
J. Clin. Anesth., vol. 12, June 2000
291