Passive smoke exposure is associated with perioperative adverse effects in children

Journal of Clinical Anesthesia (2011) 23, 47 52 Original contribution Passive smoke exposure is associated with perioperative adverse effects in children Tulay Hosten Seyidov MD (Assistant Professor of Anesthesia) a,, Levent Elemen MD (Assistant Professor of Pediatric Surgery) b, Mine Solak MD (Professor of Anesthesia) a, Melih Tugay MD (Professor of Pediatric Surgery) b, Kamil Toker MD (Professor of Anesthesia) a a Department of Anesthesia, Kocaeli University Medical Faculty, Umuttepe/Kocaeli 41380, Turkey b Department of Pediatric Surgery, Kocaeli University Medical Faculty, Umuttepe/Kocaeli 41380, Turkey Received 11 November 2009; revised 13 May 2010; accepted 16 June 2010 Keywords: Children; General anesthesia; Passive smoke exposure Abstract Study Objective: To evaluate the frequency of respiratory adverse events during general anesthesia in children passively exposed to cigarette smoke (PSE). Design: Prospective, double blinded, observational study. Setting: Operating room and recovery room of a university hospital. Measurements: Data were collected from 385 children who underwent elective surgery during general anesthesia from June to November, 2008. PSE was identified by using the child's caregivers' information. Respiratory adverse events were recorded during anesthesia and post-anesthesia. Main Results: Technique of anesthesia induction and management, distribution of patients' age, gender, surgical procedures, and perioperative analgesic methods were similar in the PSE and non-pse groups. Respiratory adverse events were reported in 58 patients (15.1%): 50 patients (21.4%) were in the PSE and 8 patients (5.3%) were in the non-pse group (P = 0.00). The frequency of laryngospasm during anesthesia (P = 0.03) and hypersecretions in the recovery room (P = 0.00) were significantly increased in the PSE group. Conclusions: Children who are exposed to environmental tobacco smoke and who undergo general anesthesia seem to have an increased risk of respiratory complications in the recovery period rather than during anesthesia. 2011 Elsevier Inc. All rights reserved. 1. Introduction Corresponding author. Kocaeli Universitesi Tıp Fakultesi Hastanesi Anesteziyoloji, AD. Kat: 1, Umuttepe/Kocaeli 41380, Turkey. Tel.: +90 532 326 23 42. E-mail address: hostentulay@hotmail.com (T.H. Seyidov). Passive smoke exposure (PSE) is a term used to refer to the mixture of side stream smoke and exhaled mainstream smoke that pollutes the air in locations where tobacco is being smoked, and it is associated with several detrimental effects on the respiratory system in children [1]. Children of 0952-8180/$ see front matter 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.jclinane.2010.06.010

48 T.H. Seyidov et al. smoking mothers have a higher incidence of respiratory disorders, reduced lung function development, and deficiencies in physical growth [2,3]. The onset of childhood asthma has been associated with smoke exposure [4]. The World Health Organization (WHO) has estimated that in 1999, almost half of the children worldwide were exposed to PSE [5]. These children may be more susceptible to adverse side effects following general anesthesia than non-exposed children [3,6]. An increased incidence of respiratory adverse events during anesthesia and in the recovery room in children with PSE has been reported [7-9]. We hypothesized that the distribution and frequency of respiratory adverse events in PSE children undergoing general anesthesia in the recovery room would be different from respiratory adverse events occurring during anesthesia. 2. Materials and methods The study was approved by the Kocaeli University Medical Faculty Committee for the Ethics on Research on Humans. All parents or caregivers accompanying their children provided informed consent prior to surgery. A total of 385 children undergoing elective surgery during general anesthesia from June to November in 2008 were evaluated prospectively. Children ranging in age from 3 months to 12 years and who were scheduled for surgery were enrolled in the study. Patients were excluded from the study if they had a history of asthma, acute or chronic airway, lung disease, or symptoms associated with an upper respiratory tract infection (URI) within the 6 weeks preceding the surgery. 2.1. Anesthetic protocol All children were anesthetized by two experienced anesthesiologists who were accompanied by anesthesia residents who had prior training of at least two years. After premedication with midazolam [0.5 mg/kg body weight for rectal administration or 0.1 mg/kg body weight for intravenous (IV) administration], patients were transferred to the operating room where standard anesthesia monitors were attached. All children were anesthetized in a standard manner either via inhalation induction and maintenance with sevoflurane, or induction with propofol 3.0 mg/kg body weight followed by maintenance with sevoflurane 2% to 4% in oxygen-nitrous oxide (35%-65%). Controlled mechanical ventilation was achieved either with endotracheal intubation or Laryngeal Mask Airway-ProSeal (LMA-P; LMA North America, Inc., San Diego, CA, USA) placement. All intubated patients received IV atropine (0.01 mg/kg body weight) and a nondepolarizing neuromuscular blocking agent (IV vecuronium 0.08 mg/kg) before intubation. Prior to extubation, the neuromuscular block was reversed with neostigmine and atropine. The techniques used for perioperative analgesia were classified by route of administration (peripheral nerve blocks: penile, ilioinguinal, and femoral; epidural and caudal blocks; and IV or rectal). Respiratory adverse events were recorded as primary outcome measures during anesthesia (induction-emergence) and post-anesthesia (recovery room). These events were defined as follows: laryngospasm (characterized by an inability to ventilate the patient's lungs and requiring either administration of continuous positive pressure or a neuromuscular blocking agent to restore ventilation), cough (duration longer than 15 sec), breath hold (duration longer than 15 sec), oxygen desaturation (SpO2 b 95%), wheezing, and the presence of unusual amounts of upper airway secretions. Each airway complication was graded; only one of the symptoms (the most severe symptom) was recorded in case of more than one of the symptoms listed above. The modified Aldrete score was recorded every 5 minutes after cessation of anesthesia. The time taken to achieve full points on the modified Aldrete score and to achieve the criteria for discharge from the recovery room was noted as duration of recovery. The occurrence of respiratory adverse events were assessed intraoperatively by the anesthesiologist who anesthetized the child and in the recovery room by the recovery room nurse. Neither the anesthesiologist nor the recovery room nurse was aware of group allocation. Passive exposure to smoke was defined as exposure to tobacco smoke produced by a household member who consumed at least one cigarette per day and who had daily contact with the child in the same or other rooms at home, which was identified by using the child's caregivers' information. Four groups were allocated for classification of PSE as follows: 1) consuming 10 or less than 10 cigarettes per day in the same room with the child (Group 1); 2) consuming 10 or less than 10 cigarettes per day in another room (Group 2); 3) consuming more than 11 cigarettes per day in the same room with the child (Group 3); and 4) consuming more than 11 cigarettes per day in another room (Group 4). Parents or caregivers of the children were given questionnaires about PSE by another recovery room nurse, who was blinded to the presence of respiratory adverse events. 2.2. Statistical analysis Statistical analysis was carried out by analysis of variance for parametric data, and Chi-Square analysis and Fisher's Exact Test for nonparametric data. Values are given as means ± SD [parametric data (mean ± SD)], and frequencies (n), and ratios (%; nonparametric). Statistical significance was set at P b 0.05, with a confidence interval of 95%. 3. Results Of the 385 patients who underwent general anesthesia, 17 patients were excluded from the study for asthma or URI

Passive smoke and general anesthesia in children 49 Table 1 Demographics: surgical and anesthetic characteristics of the patients PSE (n, %) (n=234; 60.8%) Non-PSE (n, %) (n=151; 39.2%) Weight (kg) 16.39 ± 8.18 15.66 ± 7.76 0.38 Age (yrs) 3.87 ± 3.08 3.97 ± 3.37 0.77 Duration of anesthesia (min) 80.47 ± 53.19 73.03 ± 39.96 0.14 Duration of surgery (min) 72.90 ± 52.06 65.84 ± 38.34 0.15 SpO 2 in the air room (%) 98.93 ± 6.49 99.47 ± 0.81 0.30 Duration of recovery (min) 5.45 ± 6.81 5.16 ± 5.46 0.66 ASA physical status (n, %) I 203 (86.8 %) 136 (90.1 %) 339 (88.1 %) 0.20* II 31 (13.2 %) 15 (9.9 %) 46 (11.9 %) Distribution of age groups (yrs; %) 0-1 54 (23.1 %) 39 (25.8 %) 93 (24.2 %) 0.90 1-4 97 (41.5 %) 59 (39.1 %) 156 (40.5 %) 4-7 48 (20.5 %) 29 (19.2 %) 77 (20.0 %) 7 + 35 (15.0 %) 24 (15.9 %) 59 (15.3 %) Gender (n, %) Female 82 (35.0 %) 54 (35.8 %) 136 (35.3 %) 0.48* Male 152 (65.0 %) 97 (64.2 %) 249 (64.7 %) Operation type (n, %) ENT 45 (19.2 %) 31 (20.5 %) 76 (19.7 %) 0.11 Urology 77 (32.9 %) 63 (41.7 %) 140 (36.4 %) Orthopedic 58 (24.8 %) 23 (15.2 %) 81 (21.1 %) Other 54 (23.1 %) 34 (22.5 %) 88 (22.8 %) Postoperative analgesia (n, %) Parenteral 29 (12.4%) 14 (9.2%) 43 (11.2%) 0.78 Rectal 114 (48.8%) 79 (52.3%) 193 (50.2%) Caudal-PNB 84 (35.8 %) 54 (35.6%) 138(35.8%) None 7 (3.0%) 4 (2.9%) 11 (2.8%) Anesthesia induction (n, %) Inhalation 164 (70.1 %) 110 (72.8 %) 274 (71.2 %) 0.32* Intravenous 70 (29.9 %) 41 (27.2 %) 111 (28.8 %) Muscle relaxant usage (n, %) Yes 127 (54.3 %) 74 (49.0 %) 201 (52.2 %) 0.18* No 107 (45.7 %) 77 (51.0 %) 184 (47.8 %) Airway management (n, %) ETT 126 (53.8 %) 69 (45.7 %) 195 (50.6 %) 0.07* LMA-ProSeal 108 (46.2 %) 82 (54.3 %) 190 (49.4 %) RAE (n, %) 50 (86.2 %) 8 (13.8 %) 58 (100 %) 0.00* Values given as means ± SD were analyzed by analysis of variance (F-Test). Values given as n (% in group) were analyzed by Pearson Chi-Square Test and (*) Fisher's Exact Test. PSE = passive exposure to smoke, ENT = ear, nose, throat, PNB = peripheral nerve block, ETT = endotracheal tube, RAE = respiratory adverse event. Total P 6 weeks prior to surgery. Demographic and surgical characteristics of the PSE and non-pse groups are shown in Table 1. Three-hundred thirty-nine patients (88.1%) were ASA physical status I and the remaining were ASA physical status II. Of the 385 patients reviewed, 234 (60.8%) were subjected to PSE at home while the other 151 (39.2%) patients were not subjected to PSE. The ratio of male children was higher in the study but the distribution of genders was comparable in both groups (P N 0.05). No statistically significant differences were noted with respect to ASA physical status, age, or weight between the PSE and non-pse groups. Anesthesia induction technique, distribution of perioperative analgesic methods, surgical procedures, duration of surgery, and anesthesia and recovery room stay were similar in the groups (P N 0.05). One hundred twentysix patients (53.8%) of the PSE groups underwent endotracheal intubation. In the non-pse group, the tracheas of 69 patients (45.7%) were intubated, and neuromuscular blocking agents were given to 74 patients (49.0%). There was no significant difference with regard to neuromuscular blocking agent use or airway management among the groups (P N 0.05). Respiratory adverse events were reported in 58 study patients (15.1%). Fifty patients (86.2%) in the PSE groups Table 2 Comparison of the frequency and timing of respiratory adverse events in relation to passive smoking exposure (PSE) and non-pse patients PSE n (%) Non-PSE n (%) Total n (%) P During 12 (24.0) 3 (37.5) 15 (25.9) 0.02 anesthesia Recovery 38 (76.0) 5 (62.5) 43 (74.1) 0.00 room Total 50 (100) 8 (100) 58 (100) P 0.00 0.48 P b 00.5, intergroup comparison of respiratory adverse events in the same period of anesthesia. P b 00.5, within-group comparison of respiratory adverse events in different anesthesia periods.

50 T.H. Seyidov et al. Fig. 1 Distribution of respiratory adverse events in children passively exposed to cigarette smoke. DA=during anesthesia, RR=during the recovery room period. and 8 patients (13.8%) in the non-pse groups had respiratory adverse events, and the difference was statistically significant (P = 0.00). In the PSE groups, the frequency of respiratory adverse events in the recovery room (P = 0.00) and during anesthesia (P = 0.02) was significantly greater than in the non-pse groups. The number of PSE group patients who had respiratory adverse events in the recovery room was higher than during anesthesia (P = 0.00). In the non-pse group, the number of patients who had respiratory adverse events in the recovery room versus during anesthesia were comparable (P = 0.48) (Table 2). When all the children included in the study were evaluated, intraoperative and postoperative respiratory adverse events were more frequent Table 3 Distribution of respiratory adverse events between the groups PSE Non-PSE P Cough During anesthesia 3 1 0.31 Recovery room 8 2 0.058 P 0.13 0.56 Laryngospasm During anesthesia 7 2 0.09 Recovery room 1 0 P 0.03 Hypersecretion During anesthesia 1 0 Recovery room 25 3 0.00 P 0.00 Breath hold During anesthesia 1 0 Recovery room 2 0 P 0.56 Wheezing During anesthesia 0 0 Recovery room 0 0 P Desaturation During anesthesia 0 0 Recovery room 2 0 P PSE = passive smoking exposure. P b 0.05, intergroup comparison of respiratory adverse events in the same period of anesthesia P b 0.05, within-group comparison of respiratory adverse events in different anesthesia periods. Table 4 Distribution of respiratory adverse events in the passive smoking exposure (PSE) group according to degree of smoke exposure Group PSE (n=234) Respiratory adverse P events (n=50) Group 1 155 (40.3%) 19 (12.3%) 0.001 Group 2 10 (2.6%) 2 (20.0%) Group 3 37 (9.6 %) 22 (59.5%) Group 4 32 (8.3%) 7 (21.9%) Group 1 = children from homes where 10 or fewer cigarettes per day were smoked in the same room with the child; Group 2 = children from homes where 10 or fewer cigarettes per day were smoked in another room; Group 3 = children from homes where 11 cigarettes per day were smoked in the same room with the child; Group 4 = children from homes where more than 11 cigarettes per day were smoked in another room. in intubated patients than those not intubated [38 (19.5%) vs. 20 (10.5%); P = 0.014]. Respiratory adverse events were noted in 32 (25.4%) intubated patients in the PSE group and in 18 (16.7%) patients with LMA-P, but the difference was not significant (P = 0.104). In the non-pse groups, these frequencies were 6 (8.7%) and 2 (2.4%), respectively, and the differences in these groups was not significant (P = 0.14). Evaluation of respiratory adverse event distribution in the PSE groups showed an increased frequency of laryngospasm during anesthesia (P = 0.03) and hypersecretions in the recovery room (P = 0.00) (Fig. 1). Only one PSE group patient who developed laryngospasm during anesthesia needed a neuromuscular blocking agent; in the remaining patients, laryngospasm was improved with positive pressure ventilation. The number of PSE group patients who had hypersecretions was higher than in the non-pse groups (P = 0.00). In one patient, who had desaturation in the recovery room, jaw thrust maneuver resolved the situation; thus, endotracheal intubation was not required. Evaluation of respiratory adverse event distribution in the non-pse group did not show any significant differences (P = 0.48) (Table 3). Additional logistic regression analysis showed no correlation between respiratory adverse events and ASA physical status, gender, age, anesthesia induction, muscle relaxant usage, or airway management. A comparison of the degree of PSE with respiratory adverse event frequency showed that, as the degree of PSE increased, complications also increased significantly (P = 0.001). In cases where more than 10 cigarettes were smoked per day near the child, the respiratory adverse event rate increased as high as 60% (Table 4). 4. Discussion Despite the establishment of new guidelines to improve anesthetic practice, respiratory adverse events are still one of the major causes of claims reported in children [10,11].

Passive smoke and general anesthesia in children Several factors influence the occurrence of respiratory adverse events. The age group of the child is one of these factors. In children, respiratory adverse events are more often reported in infants than in older children in the intraoperative and postoperative periods. The type of surgery is also important. The frequency of respiratory adverse events was higher in ear, nose, and throat (ENT) surgery. Intraoperative and postoperative adverse events were more frequent in patients whose tracheas were intubated [12,13]. While PSE is an important risk factor in the development of respiratory adverse events, Jones et al. [9] reported that airway complications are higher, with mask ventilation [12]. A significant component of perioperative risk derives from postoperative pain, and effects of pharmacologic pain management in children. A regional block before surgery is recommended whenever possible. Caudal epidural blockade is widely used to provide perioperative analgesia in pediatric practice. Currently, peripheral nerve block improves pain management and opioid analgesia-induced side effects, and it provides a shorter postoperative recovery time than does systemic analgesia with opioids [14]. The similarity of the age groups, surgery type, as well as the fact that the anesthesia and postoperative analgesia methods and airway maintenance were similar in the PSE and non-pse groups in our study, suggest the negative impact of PSE in the development of respiratory adverse events. In the present series, the increased frequency of respiratory adverse events (15.1%), which was higher than that of a previously published study, may be attributed to the increased frequency of hypersecretions [12]. Jones et al. [9] showed an increased frequency of hypersecretions in the PSE group. In addition, this was significantly increased in the recovery room versus during anesthesia. An experimental study of the pathologic changes in airways of pigs that were exposed to cigarette smoke showed that epithelial mucous (ie, goblet) cell numbers in the trachea and airways of the lungs were markedly increased [15]. Thus, over-production of upper airway secretions in our series might have been related to the increase in the number of goblet cells in children exposed to smoke. The increased incidence of respiratory adverse events in PSE children in the recovery room is an important fact, which is subject to clinical practice. Skolnick et al. [8] noted increased rates of laryngospasm and severe coughing in PSE children in the recovery room. Similarly, Drowngowski et al. [16] reported that coughing and breath holding in the recovery room significantly increased with PSE versus non-pse children. Lyons et al. [17] found that oxygen desaturation in the recovery room was significantly more common in PSE children. Children exposed to household tobacco smoke and undergoing general anesthesia were more prone to post-extubation laryngospasm with a tenfold increased incidence versus that of non-exposed children (9.8% vs. 0.9%) [7]. We found the frequency of laryngospasm to be 2.8% in the PSE groups and 1.32% in the non-pse groups; this finding was lower than what was reported by Laksimpathy et al. [7]. This discrepancy may be attributed to our exclusion criterion for patients who had a URI 6 weeks before surgery as compared with Laksimpathy et al.'s two-week exclusion time. A previous study suggested that a child with an URI remained at risk for up to 6 weeks after the URI was resolved. The child with a URI was at increased risk for perioperative respiratory complications, including laryngospasm, bronchospasm, and arterial oxygen desaturation [18-21]. In addition, children with active and recent URI (within 4 wks) were at increased risk of adverse respiratory events, particularly if they had a history of environmental tobacco smoke exposure [22]. Adult smokers require longer anesthetic times and they spend more time in the Postanesthesia Care Unit (PACU) than do nonsmokers. Both effects have been correlated with the number of cigarettes smoked [23]. In spite of the higher frequency of respiratory adverse events in the recovery room, we did not find a longer stay period in the recovery room in the PSE group. We were unable to detect prolonged recovery times in children exposed to PSE [16], which may be attributed to the high skill and experience of our recovery room nurses, who are accustomed to children with complications. The present study has limitations; we relied on the children's caregivers with respect to identification of PSE. 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