Uma A. Pandit

Risk factors for perioperative adverse respiratory events in children with upper respiratory tract infections

Background Anesthesia for the child who presents for surgery with an upper respiratory infection (URI) presents a challenge for the anesthesiologist. The current prospective study was designed to determine the incidence of and risk factors for adverse respiratory events in children with URIs undergoing elective surgical procedures. Methods The study population included 1,078 children aged 1 month to 18 yr who presented for an elective surgical procedure. Parents were given a short questionnaire detailing their child’s demographics, medical history, and presence of any symptoms of a URI. Data regarding the incidence and severity of perioperative respiratory events were collected prospectively. Adverse respiratory events (any episode of laryngospasm, bronchospasm, breath holding > 15 s, oxygen saturation < 90%, or severe cough) were recorded. In addition, parents were contacted 1 and 7 days after surgery to determine the child’s postoperative course. Results There were no differences between children with active URIs, recent URIs (within 4 weeks), and asymptomatic children with respect to the incidences of laryngospasm and bronchospasm. However, children with active and recent URIs had significantly more episodes of breath holding, major desaturation (oxygen saturation < 90%) events, and a greater incidence of overall adverse respiratory events than children with no URIs. Independent risk factors for adverse respiratory events in children with active URIs included use of an endotracheal tube (< 5 yr of age), history of prematurity, history of reactive airway disease, paternal smoking, surgery involving the airway, the presence of copious secretions, and nasal congestion. Although children with URIs had a greater incidence of adverse respiratory events, none were associated with any long-term adverse sequelae. Conclusions The current study identified several risk factors for perioperative adverse respiratory events in children with URIs. Although children with acute and recent URIs are at greater risk for respiratory complications, these results suggest that most of these children can undergo elective procedures without significant increase in adverse anesthetic outcomes.

Use of the laryngeal mask airway in children with upper respiratory tract infections: a comparison with endotracheal intubation.

Several studies suggest that placement of an endotracheal tube (ETT) in a child with an upper respiratory infection (URI) increases the risk of complications.However, the development of the laryngeal mask airway (LMA) has provided anesthesiologists with an alternative means of airway management. This study was therefore designed to evaluate the use of the LMA in children with URIs and to compare it with the ETT. The study sample consisted of 82 pediatric patients (3 mo to 16 yr of age) who presented for elective surgery with an URI. Patients with URIs were randomly allocated to receive either an ETT (n = 41) or a LMA (n = 41) and were followed for the appearance and severity of any perioperative complications. The two groups were similar with respect to age, gender, anesthesia and surgery times, number of attempts at tube placement, and presenting URI symptoms. There were no differences between groups in the incidence of cough, breath-holding, excessive secretions, or arrhythmias. Although one patient in the ETT group required a muscle relaxant for laryngospasm, the overall incidence of laryngospasm was similar between the two groups. There was, however, a significantly greater incidence of mild bronchospasm in the ETT group compared with the LMA group (12.2% vs 0%, P < 0.05). The incidence of major arterial oxygen desaturation events (Spo2 <90%) during placement of the airway device was also significantly increased in the ETT group (12.5% vs 0%, P < 0.05). Furthermore, the total number of all episodes of respiratory complications, i.e., breath-holding, laryngospasm, bronchospasm, and major oxygen desaturation, was significantly greater in the ETT group (35 vs 19, P < 0.05). Despite this, all respiratory complications were easily managed, and there were no adverse sequelae. Although the risks associated with anesthetizing a child with an URI remain controversial, results from this study suggest that the LMA offers a suitable alternative to the ETT for use in children with URIs. Implications: This study compares the use of the laryngeal mask airway with the endotracheal tube for airway management in children with upper respiratory infections. Results suggest that if the decision is made to proceed with anesthesia for the child with an upper respiratory infection, then the laryngeal mask airway provides a suitable alternative to the endotracheal tube. (Anesth Analg 1998;86:706-11)

Dose-response study of droperidol and metoclopramide as antiemetics for outpatient anesthesia

During the past decade the demand for outpatient surgery has grown rapidly. To keep pace with the changing surgical environment, anesthesiologists have been modifying their anesthetic techniques to ensure a more rapid and a smoother recovery. However, postoperative nausea and vomiting remain the most common anesthesia-related side effects in outpatient surgical facilities (1,2). The incidence of postoperative nausea and vomiting in female outpatients undergoing laparoscopy has been reported to be as high as 50-60% (3). The incidences after strabismus surgery (4) and after therapeutic abortions (5) are also high. A prophylactic antiemetic would be of great value in outpatient surgery and anesthesia. A large number of papers have been published suggesting the use of droperidol, a butyrophenone derivative, as a prophylactic antiemetic agent. Although the majority of the authors found droperidol to be an effective antiemetic, the recommended doses vary widely (4,643). However, side effects, especially somnolence, have been reported with larger doses (4,9). Metoclopramide, a dopaminergic receptor blocker devoid of sedative effects, has also been advocated as an antiemetic, but conflicting results have been reported regarding its efficacy (5,lO-14). A recent paper by Rao, et al. (15) reported no nausea or

Upper respiratory tract infections and general anaesthesia in children : Peri-operative complications and oxygen saturation

Conflicting reports regarding the hazards of anaesthesia in children presenting for surgery with an upper respiratory tract infection have appeared in the literature. In the present study 130 children undergoing general anaesthesia with face mask for myringotomy and grommet insertion were graded as having either an acute or recent upper respiratory tract infection or were asymptomatic according to predetermined clinical symptoms and signs. The severity of respiratory and related complications were scored during induction, emergence and recovery. The peripheral oxygen saturation was recorded during induction, emergence, transfer to the recovery ward and in the recovery ward itself. There were no significant differences (p > 0.05) in the complication scores between the three groups of children. However, the incidence of hypoxaemia (oxygen saturation ± 93%) was significantly greater during transfer in the acute infection group (p = 0.001) and the recent infection group (p = 0.02), as well as during recovery in the acute group (p = 0.03) compared with asymptomatic children.

Vomiting after outpatient tonsillectomy and adenoidectomy in children: The role of nitrous oxide

The role of nitrous oxide anesthesia in causing postoperative vomiting (POV) was studied in 60 children undergoing outpatient tonsillectomy and adenoidectomy.In this controlled, randomized, double-blind investigation, anesthesia was induced by inhalation of a volatile anesthetic in both groups. The nonnitrous oxide group received no nitrous oxide, even during induction of anesthesia. Designated nurses in the postanesthesia care unit (PACU) who were blinded to the anesthetic technique evaluated the incidence and the severity of the patients emetic symptoms, both in the PACU as well as after discharge. Pharmacologic intervention was administered on the basis of evaluation by the nurses. Although a high incidence of POV was noted in both groups, there was no difference in either the incidence or the severity of POV between the group receiving nitrous oxide and the group receiving no nitrous oxide. (Anesth Analg 1995;80:230-3)

Risk Factors for Adverse Postoperative Outcomes in Children Presenting for Cardiac Surgery with Upper Respiratory Tract Infections

Background Otherwise healthy children who present for elective surgery with an upper respiratory infection (URI) may be at risk for perioperative respiratory complications. This risk may be increased in children with congenital heart disease who undergo cardiac surgery while harboring a URI because of their compromised cardiopulmonary status. Therefore, this study was designed to determine the incidence of peri- and postoperative complications in children undergoing cardiac surgery while harboring a URI. Methods The study population consisted of 713 children scheduled to undergo cardiac surgery. Of these, 96 had symptoms of URI, and 617 were asymptomatic. Children were followed prospectively from induction of anesthesia to discharge from the hospital to determine the incidence of postoperative respiratory, cardiovascular, neurologic, and surgical adverse events. Duration of postoperative ventilation, time in the intensive care unit (ICU), and length of hospital stay were also recorded. Results Children with URIs had a significantly higher incidence of respiratory and multiple postoperative complications than children with no URIs (29.2 vs. 17.3% and 25 vs. 10.3%, respectively;P < 0.01) and a higher incidence of postoperative bacterial infections (5.2 vs. 1.0%;P = 0.01). Furthermore, logistic regression indicated that the presence of a URI was an independent risk factor for multiple postoperative complications and postoperative infections in children undergoing open heart surgery. Children with URIs also stayed longer in the intensive care unit than children with no URIs (75.9 ± 89.8 h vs. 57.7 ± 63.8, respectively;P < 0.01). However, the overall length of hospital stay was not significantly different (8.4 vs. 7.8 days, URI vs. non-URI groups;P > 0.05). Conclusions The presence of a URI was predictive of postoperative infection and multiple complications in children presenting for cardiac surgery. Despite this, the presence of a URI does not appear to affect the patients overall length of hospital stay nor the development of long-term sequelae.

Time course of antirecall effect of diazepam and lorazepam following oral administration.

&NA; The time course of antirecall effect and grades of sedation after the oral administration of diazepam and lorazepam were determined in 120 patients. Three standard doses of each drug were employed. Grades of sedation following oral diazepam were dose related, with a latency of 30‐60 min and duration of 120‐150 min. All three doses of lorazepam produced significantly more sedation with a similar latency (30‐60 min) but longer duration (more than 240 min). Peak frequencies of the antirecall effects of diazepam 10, 15, and 20 mg were 5, 20, and 30 per cent, respectively. The duration was about two hours. Peak frequencies of the antirecall effect after lorazepam 2, 3, and 4 mg were 30, 45, and 72 per cent, respectively. Latency of peak action was about 60‐90 min for all the doses, but the duration, especially with 3 and 4 mg doses, was long (4 h).

Toast and tea before elective surgery? A national survey on current practice.

A more tolerant approach to preoperative fasting guidelines for healthy adults undergoing elective surgery was recently recommended by a task force appointed by the American Society of Anesthesiologists. This recommendation liberalizes the intake of clear liquids and specifically allows a light breakfast (e.g., toast and tea or coffee) up to 6 h before elective surgery. We conducted a national survey to determine whether anesthesiologists giving anesthesia in an outpatient setting in the United States were currently following these recommendations, and whether institutional policy reflects these new guidelines. The population consisted of the entire active membership of the Society for Ambulatory Anesthesia, providing an initial sample size of 623 subjects. Most conservatively calculated, we had a response rate of 59.6%. A total of 62% of the respondents said they have an institutional policy in place to allow clear liquids orally 2–3 h before the induction of anesthesia. However, only 35% of the respondents said their institutions had a policy in place allowing a light breakfast 6 h before elective surgery. Nevertheless, only 3% of the responders said they would cancel the operation if a patient actually arrived at the facility after consuming a light breakfast, such as toast and tea 6 h before elective surgery, 32% would delay surgery to later that day, and 65% would proceed without delay. We concluded that most anesthesiologists practicing outpatient anesthesia in the United States have already changed their practice pattern to conform to the recent recommendations of the American Society of Anesthesiologists task force on preoperative fasting time. Implications Findings of this national survey conducted among active members of the Society for Ambulatory Anesthesia may encourage anesthesiologists throughout the world to take a more liberal attitude toward allowing clear liquids 2–3 h and a light breakfast 6 h before an elective surgery in healthy patients.

A comparison of continuous epidural infusion and intermittent intravenous bolus doses of morphine in children undergoing selective dorsal rhizotomy

BACKGROUND AND OBJECTIVES Selective dorsal rhizotomy (SDR) is associated with moderale to severe postoperative pain. Although the efficacy of epidural analgesia in this population has been demonstrated, it has not been compared with conventional intravenous (i.v.) analgesia. This prospective study compared the effects of epidural and i.v. morphine regarding postoperative analgesia, side effects, and outcomes in children following SDR. METHODS Twenty-seven children were randomized to receive either epidural or i.v. analgesia. Children in the epidural group had a catheter placed by the neurosurgeon and received preservative-free morphine (Duramorph) 30 microg/kg, followed by an infusion of 3 microg/kg/h for 3 days. Children in the i.v. group received morphine 0.05-0.1 mg/kg intraoperatively, followed by 0.02 mg/kg doses postoperatively administered by nurses via a patient-controlled analgesia device. RESULTS The epidural group experienced lower pain scores (P = .04) and fewer muscle spasms (P < or = .04), and tolerated activity better (P < or = .02) during the early postoperative period than the i.v. group. Side effects were similar between groups, with no respiratory depression in either group. Parents of children in both groups perceived an adequate level of comfort and were very satisfied with the analgesic technique. Additionally, parents believed that their childs postoperative pain was less than anticipated (P < or = .01). CONCLUSIONS Both techniques provided effective postoperative analgesia with a similar incidence of side effects; however, our findings suggest that continuous infusions of epidural morphine improved overall comfort with lower pain scores, fewer muscle spasms, and improved tolerance of activity during the initial postoperative period.

Induction and recovery characteristics of isoflurane and halothane anaesthesia for short outpatient operations in children

Induction and recovery characteristics of isoflurane anaesthesia were compared with halothane anaesthesia during outpatient myringotomy and placement of Sheely ventilation tubes in 101 unpremedicated children. Compared with halothane, isoflurane resulted in prolonged induction times and inferior induction scores due to increased salivation, coughing, breathholding and laryngospasm. However, when modified by halothane induction, isoflurane anaesthesia decreased induction time and improved induction scores. Induction with thiamylal 4 mg/kg did not improve induction scores significantly. Recovery times from halothane plus isoflurane and pure isoflurane anaesthesia were quicker than pure halothane and thiamylal plus isoflurane, although this was not statistically significant. Compared to halothane, anaesthetic induction using isoflurane is associated with an increased incidence of respiratory problems in unpremedicated children.