Pediatric Pulmonologyeri A Proposed Pediatric Risk Stratification Method (PediaRiSM) for Post Operative Pulmonary Complication for Cardiothoracic Surgery Beverly D. Dela Cruz, MD; Ma. Nerissa A. De Leon, MD; Ma. Theresa Policarpio, MD; Ana Marie Reyes, MD; Anjanette R. De Leon, MD; Dulce Requiron, MD; Gladys G. Gillera, MD; Milagros Bautista, MD; Teresita S. De Guia, MD Background --- Pulmonary complications are the most common form of posoperative morbidity expe- rienced by a pediatric patient undergoing surgery, particularly cardiothoracic surgery. There has been no preoperative risk stratification method available to evaluate pediatric patients. This study aimed to propose a risk stratification method for post-operative pulmonary outcomes among pediatric patients undergoing cardiothoracic surgery. Methods --- We retrospectively reviewed medical records of 506 children aged 6 to 19 years old who underwent cardiothoracic surgery from June 2003 to 2008. Preoperative risk factors extracted included age, gender, cardiothoracic anomalies, nutritional status, and co-morbidities. Laboratory data included complete blood count, 2D echocardiogram, chest radiograph, pulmonary function tests and blood gas analysis. These parameters were associated with pulmonary complications observed such as atelectasis, pleural effusion, pneumonia, pneumothorax, pulmonary edema and airway problem. Results --- Three hundred thirty (65.2%) out of 506 children developed post-operative pulmonary complications with atelectasis (25.6%) being the most frequent complication observed. Among the clinical variables analyzed, only three variables were independently predictive of post-operative complications, namely: FVC of < 80 ( p=.030); blood pH of < 7.35 ( p=.024) and white blood cell count of > 12 T per cubic mm (p=.0001). ROC analysis derived the best minimum cut-off score of 11 points with a sensitivity of 88.8%, specificity of 85.1%, and positive likelihood ratio (LR+) of 5.41. The overall accuracy of the scoring index was 81.6% [ p=0.002]. Conclusion --- Pre-operative risk stratification for pediatric patients undergoing cardiothoracic surgery using this scoring index is simple and rapid. Phil Heart Center J 2012; 16(2):35-46 Key Words: PediaRiSM n Risk Stratification n Postoperative complication ulmonary complications are the most “gold standard” or single test to predict common form of postoperative morbidity the patient‘s response postoperatively. Instead, experiencedP by pediatric patients who a multitude of procedures and tests have undergo surgical abdominal procedures and been described and performed in adult thoracotomy; and they frequently occur after patients and these are often used to eva- surgical cardiac procedures.1 The American luate children and adolescent patients.2 A Academy of Pediatrics recommends guide- scoring system suggested by Dr. Barry lines for the preoperative anesthetic environ- Shapiro to evaluate the risk for postoperative ment for children undergoing any kind of pulmonary complications this scheme allows surgery. Few prospective trials critically the clinician to stratify patients undergoing examined the various criteria used in preopera- thoracic and upper abdominal surgery. In tive assessment. The problem with the phy- adult patients, it can be stratified on clinical siologic evaluation of the patient undergoing grounds into low-, medium-, and high-risk surgery, particularly in pediatric thoracic categories. These categories, along with consi- and cardiovascular, is that there is as yet no deration of the type and urgency of surgery, Travel Award for Young Researcher 14th Annual Congress of the Asia Pacific Society of Respiratory (APSR) and 3rd Joint Congress of the APSR/ACCP November 14-18, 2009 held in Seoul, Korea. Correspondence to Dr. Beverly D. Dela Cruz, Division of Pulmonary Medi- cine and Critical Care, Section of Pediatric Pulmonology. Philippine Heart Center, East Avenue, Quezon City, Philippines 1100 Available at http://www.phc.gov.ph/journal/publication copyright by Philippine Heart Center, 2012 ISSN 0018-9034 35 36 Phil Heart Center J May - August 2012 allow for a reasonable approach to pre- of complications postoperatively and to de- operative testing. 3 Children and adolescent termine the accuracy of a simple pre-operative with congenital heart disease who under- scoring system to predict post-operative com- went surgical repair are a special group of pa- plications among children undergoing cardio- tients associated with an increased risk of de- thoracic surgery. velopment of post-operative pulmonary com- plications. Most postoperative pulmonary com- Methodology plications such as pneumonitis, bronchospasm, lobar collapse, prolonged mechanical ventila- tion and generalized pulmonary dysfunction de- We made a retrospective review of the charts velop as a result of changes in lung volumes of children 6 to 19 years old who underwent that occur in response to dysfunction of cardiothoracic surgery from June 2003 to June muscles of respiration and other changes 2008. Data was extracted from Medical Records in chest wall mechanics.4 Two local studies of the hospital. Patients were identified by dis- done by AMA Reyes et al5 and GL Gillera et charge diagnosis, PICU admissions log, and al6 last 2001 and 2004 respectively showed Pediatric Critical Care for Congenital Heart that the incidence of pulmonary complica- Disease from the surgical databases. tions was higher among this group of children A checklist /evaluation form was provided and adolescents. To our knowledge there to assess the preoperative risk factors such as have been no local guidelines and standard demographic characteristics (age, gender and protocol for pediatric evaluation or risk primary cardiothoracic anomalies), nutritional stratification for postoperative complications status, presence or absence of co-morbid for cardiothoracic surgery. We made a 6-year diseases, neurologic status, and past medical retrospective review of all young patients history of each patient. Laboratory data such undergoing cardiothoracic surgery from year as complete blood count, pulmonary artery 2003-2008 at our institution, and attempted to pressure and chest radiographs prior to surgi- identify specific pulmonary risk factors that may cal procedure were reviewed. American Society underlie the development of postoperative pul- of Anesthesiologist (ASA) physical status monary complications. was also evaluated. We also recorded periopera- tive parameters such as surgical procedure, The goal of preoperative evaluation of the total duration of surgery, cardiopulmonary by- surgical patient is to identify patients at risk for pass time, aortic cross-clamp time; and duration complications during or following cardiothoracic of postoperative mechanical ventilation. Opera- surgery but up to this time there have been no bility was evaluated by means of pulmonary standard guidelines for risk stratification or as- function tests and blood gas analysis. sessment in pediatric age group. For this rea- son, this study was meant to establish a scoring Postoperative complications and mortality system for risk stratification for postope- were considered as those occurring within rative pulmonary complications and to deter- seven (7) days postoperatively or over a longer mine predictors of complications in patients at period if the patient was still in the hospital. risk for post-operative pulmonary complica- tions. The objective of this study is to deve- Descriptive data were expressed as lop guidelines and propose a scoring system medians or as means for normally distribu- for pediatric risk stratification for postopera- ted data. Group and categorical data were tive pulmonary complications in patient analyzed with appropriate statistical tools. The undergoing cardiothoracic surgery; to deter- study population was divided into 2 groups mine the risk factors for the development of based on the presence or absence of compli- postoperative pulmonary complications in cations. The pulmonary complications are as children and adolescents with congenital heart follows: (1) Atelectasis – defined as a radio- defects undergoing cardiac operations; to assess graphic findings of lobar infiltrate and volume the degree of correlation of preoperative loss in the absence of clinical signs of infec- and perioperative risk factors and verify tion; (2) Pleural effusion – patients with pleural whether they have a role as a predictor drainage > 5ml/kg/day and requiring continued Dela Cruz et al PediaRiSM for Post-op Complications 37 chest tube drainage beyond the 3rd post opera- and their corresponding odd ratios to determine tive day; (3) Pneumothorax; (4) Pulmonary the independent predictors of treatment failure. congestion/ edema; (5) Airway problem- bron- Odd ratios of greater than 1, falling within the chospasm, wheezing, obstruction; and (6) Pneu- 95% confidence limits and possessing a p-value monia- new or progression of localized infil- of less than 0.05 were considered signifi- trates on CXR with fever and leukocy- cant prognostic factors. Score transformations tosis >10,000/mm3. A system for evaluating were done on these predictors by dividing the risk category for pulmonary complica- them by the smallest beta-coefficient of tions was based on point system. Each of the mode. A raw score was done by dividing the 3 categories was evaluated and patient this coefficient by the number of analyzed was ascribed a total score from 0-16 (only factors. A score was assigned by rounding one score