Does an objective system-based approach improve assessment of perioperative risk in children? A preliminary evaluation of the 'NARCO'.

BACKGROUND: This study evaluated whether an objective tool would provide a more reliable and valid assessment of perioperative risk compared with the ASA-physical status (ASA-PS) in children. METHODS: A system-based risk assessment tool was developed using these categories: Neurological, Airway, Respiratory, Cardiovascular, and Other (NARCO) with a subcomponent grading surgical severity (SS). Anaesthesiologists reviewed the preoperative assessments and assigned NARCO, SS, and ASA-PS scores independently. Perioperative outcomes were recorded by trained observers. Validity and reliability of the tools were evaluated. RESULTS: NARCO correlated with ASA-PS (ρ=0.664; P<0.01) supporting its criterion validity. Inter-rater reliability of the measures was supported (intraclass correlation coefficients 0.71-0.96; κ 0.43-0.87) except for the Airway category. Measures of exact agreement were slightly better for NARCO compared with ASA-PS. NARCO, SS, and ASA-PS scores correlated significantly with perioperative escalation of care, adverse events (AE), hospital length of stay, and admission status. Correlations between NARCO and ASA-PS and outcomes improved when SS was factored into their coding. There were significant, but low, correlations between all measures and mortality. The odds of having escalation of care, AE, and mortality were 5-47 times greater among children with higher risk scores. CONCLUSIONS: Findings suggest that all measures of outcome have acceptable to excellent reliability with a slight improvement in agreement for the NARCO compared with the ASA-PS. This study supports the validity of both the NARCO and the ASA-PS in predicting perioperative risk in children with a slight improvement in correlations when combined with the SS score.

Awareness in children: a secondary analysis of five cohort studies.

Five recent cohort studies have shown a frequency of awareness in paediatric anaesthesia of between 0.2% and 1.2%, but they were not individually large enough to identify risk factors. This study pooled raw data from these five studies to identify factors associated with awareness in children. The outcome of awareness was taken as the cases judged to be most likely awareness cases in each study. Logistic regression was used to identify awareness-associated factors. A combined sample of 4486 anaesthetics revealed 33 cases of awareness. Unadjusted analysis demonstrated weak evidence that nitrous oxide used as an anaesthetic maintenance adjunct was associated with awareness (OR 2.04 (95% CI 0.97-4.33), p=0.06), and some evidence that use of a tracheal tube was associated with awareness (OR 2.78 (95% CI 1.11-6.94), p=0.03). Multivariable regression analysis revealed that nitrous oxide maintenance and use of a tracheal tube were independently associated with awareness (nitrous oxide, OR 2.4 (95% CI 1.08-5.32), p=0.03; tracheal tube, OR 3.0 (95% CI 1.20-7.56), p=0.02).

Pain location and widespread pain in youth with orthopaedic conditions: Exploration of the reliability and validity of a body map.

BACKGROUND: Pain location and widespread pain are important but underexamined dimensions of paediatric pain. Body map tools to assess pain location in youth have been used for several decades, but few studies have established reliability and validity of these measures. The purpose of this study was to explore the reliability and validity of a pain body map among youth with orthopaedic conditions before surgery. METHOD: Youth ages 10-17 years completed the body map and other self-reported outcomes at their preoperative clinic visit and at their day of surgery. RESULTS: Most (91.7%) youth had small discrepancy between body map scores at preoperative clinic visit (baseline) and day of surgery (second assessment), and site-to-site agreement ranged from 78% to 98%. Those with back and lower extremity diagnoses had high correspondence between body map sites and diagnostic sites. Body map scores and widespread pain were associated with other dimensions of pain, as well as other patient-reported outcomes. Higher pain intensity and widespread pain predicted greater discrepancy between body map scores. CONCLUSIONS: These results support the use of body map tools in further research examining widespread pain among youth by demonstrating adequate reliability, descriptive validity and associative validity. SIGNIFICANCE: These results contribute to the limited information regarding psychometric properties of paediatric pain body maps, provide novel information about widespread pain among youth undergoing orthopaedic surgeries, and pave the way for improved assessment and treatment of paediatric pain.

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 child's 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.

Effects of anesthetic technique on side effects associated with fentanyl Oralet premedication.

STUDY OBJECTIVES: To evaluate the efficacy of 5 to 10 micrograms/kg of oral transmucosal fentanyl citrate (OTFC) as an anesthetic premedication, and to determine whether propofol induction reduces postoperative nausea and vomiting (PONV) in pediatric patients premedicated with OTFC undergoing outpatient surgery. DESIGN: Prospective, randomized, double-blinded study. SETTINGS: University of Michigan Health Care Systems and University of Arizona. PARTICIPANTS: 62 ASA physical status I and II children aged 4 to 14 years (8.9 +/- 0.5 years). INTERVENTIONS: Subjects were randomly assigned to one of four groups: (1) OTFC premedication and halothane induction; (2) OTFC premedication and propofol induction; (3) placebo premedication and halothane induction; and (4) placebo premedication and propofol induction. OTFC or placebo was administered 30 minutes prior to induction, and activity (sedation), apprehension, and cooperation scores were recorded before, at 15 and 30 minutes after study drug, and on induction. All perioperative adverse events were recorded. MEASUREMENTS AND MAIN RESULTS: Children who received OTFC became drowsier and had a significant change from baseline in combined activity, apprehension, and cooperation scores, whereas those who received placebo became less cooperative at induction. Patients who received OTFC experienced more adverse events overall (p < 0.001) than patients who received placebo. Additionally, OTFC patients experienced more vomiting (p < 0.001) and pruritus (p = 0.049) than controls. The incidence of PONV in patients who received OTFC and halothane induction was 50%, compared to 30% in patients receiving OTFC and a propofol induction (p = NS). CONCLUSIONS: OTFC in doses of 5 to 10 micrograms/kg was effective in producing sedation and facilitating cooperation with induction; however, it was associated with significant PONV in our study. Although propofol induction did not significantly reduce PONV in our study, further study with a larger sample, and with propofol as the sole anesthetic, may be warranted.

Prolonged recovery stay and unplanned admission of the pediatric surgical outpatient: an observational study.

STUDY OBJECTIVE: To determine the incidence of and reasons for prolonged length of stay in the postanesthesia care unit and unplanned hospital admissions of children scheduled for outpatient surgery. DESIGN: Prospective, observational cohort study. SETTING: C. S. Mott Children's Hospital, a tertiary care setting. PATIENTS: 168 ASA physical status I, II, and III children (birth to 18 years), 130 of whom experienced a prolonged length of stay and 61 who had an unplanned hospital admissions. MEASUREMENTS AND MAIN RESULTS: 3.9% of annual outpatient population experienced a prolonged length of stay, and 1.9% had an unplanned outpatient admission. Prolonged length of stay was most commonly due to postoperative nausea and vomiting (19%) or respiratory complications (16%), whereas unplanned hospital admissions were primarily for respiratory or surgical reasons (32% and 30%, respectively). Higher ASA status had a significant direct relationship with the incidence of unplanned outpatient admission and respiratory complications. Although most families were satisfied with the length of their child's care, 28% of parents whose children were sent home after a prolonged length of stay would have preferred a short hospital admission, and 16% of parents of children with an unplanned hospital admission would have preferred a longer stay in recovery and discharge home. CONCLUSION: Prolonged length of stay and unplanned hospital admissions were uncommon outcomes following pediatric outpatient surgery. However, the impact of such outcomes on hospital staffing and family convenience may have implications related to cost containment and patient satisfaction.

Cancellation of pediatric outpatient surgery: economic and emotional implications for patients and their families.

STUDY OBJECTIVE: To determine the cause and timing of case cancellation in a pediatric outpatient surgical population, and to examine the economic and emotional impact of such cancellations on patients and their families. DESIGN: Questionnaire survey. SETTING: Outpatient surgery unit of a large university children's hospital. PARTICIPANTS: 127 parents of children whose elective outpatient surgery had been cancelled. INTERVENTIONS: A total of 200 questionnaires were mailed to the parents of children who had their outpatient surgery cancelled. MEASUREMENTS AND MAIN RESULTS: Of those children whose surgery had been cancelled, 34.6% were due to upper respiratory infections (URIs), 30.7% for other medical reasons, and the balance for scheduling errors, because the child had not fasted, or for difficulties with transportation. The majority of surgeries (58.3%) were cancelled prior to their scheduled surgery date. However, 18.9% were cancelled on the day of surgery prior to leaving for the hospital and 22.8% were cancelled on arrival at the outpatient surgery clinic. Of those patients whose surgeries were not cancelled until they arrived at the hospital, 38.5% of mothers and 50.0% of fathers missed a day of work and, of these, 53.3% and 42.1%, respectively, went unpaid for the work day missed. The mean number of miles driven (round trip) to the hospital for a cancelled operation was 158.8 miles (range 8 to 1,350 miles). Additional testing and new appointments were ordered in 25.2% of the cancelled cases. 45% of parents and 16% of children were disappointed by the cancellation; 16% of parents were frustrated by the cancellation and 3.3% were angry. CONCLUSIONS: This study suggests that last-minute cancellation of surgery has an important impact on patients and their families and suggests a need to review present protocols for screening patients prior to surgery.

Pain relief in children following outpatient surgery.

STUDY OBJECTIVE: To evaluate perioperative analgesia, prescription patterns, pain relief, and parental care of children undergoing outpatient surgery. DESIGN: Prospective data collection and parental interview. SETTING: Large tertiary care, university-based medical center. PATIENTS: 471 children aged between 10 months and 18 years who underwent an outpatient surgical procedure expected to be associated with pain. MEASUREMENTS AND MAIN RESULTS: All perioperative data regarding analgesia, antiemetics, postoperative pain scores, and discharge prescriptions were recorded. Parents were telephoned 24 hours following surgery, and data concerning their child's pain relief, analgesic and antiemetic usage, and their ability to care for their child were obtained. Of the 460 patients questioned, 97% were described by their parents as having adequate, good, or very good pain relief (acceptable) during the first 24 hours postoperatively, whereas only 15 (3%) had poor pain relief (unacceptable). All patients received some form of analgesia intraoperatively. The children with poor pain relief were more likely to have experienced postoperative nausea and vomiting (p = 0.01) and were more difficult to care for at home (p < 0.0001). In a subset of 185 patients who had genitourinary procedures, those who received regional analgesia reported better pain relief (p = 0.05). CONCLUSIONS: Despite a wide range of surgical procedures being performed on children on an ambulatory basis, current selection of patients for outpatient surgery is appropriate given the ability of the parents to manage their children's pain and to care for their children at home.

Evaluation of simethicone for the treatment of postoperative abdominal discomfort in infants.

STUDY OBJECTIVE: To determine whether abdominal discomfort is a cause for distress symptoms in infants following administration of inhalational anesthesia, and to evaluate the effectiveness of simethicone in treating this discomfort. DESIGN: Randomized, double-blinded study. SETTING: Large tertiary care, university-based medical center. PATIENTS: 175 ASA physical status I and II infants under 28 months of age who underwent an inhalational anesthetic for a variety of procedures that were expected to cause relatively little pain. INTERVENTIONS: Children were assessed for the presence of postoperative abdominal discomfort, and, if evident, were randomly given either simethicone or placebo in a double-blinded fashion. MEASUREMENTS AND MAIN RESULTS: Abdominal discomfort was measured using the Faces Legs Activity Cry and Consolability (FLACC) Behavioral Pain Scale. Scores were recorded pre-drug; at 10, 20, and 30 minutes following drug administration; and at discharge. If discomfort had not resolved within 15 minutes after the drug was given, routine analgesics or other medications were administered. Abdominal girth was measured preoperatively, on admission into the postanesthesia care unit (PACU), and at discharge. 21% of infants exhibited symptoms of abdominal discomfort postoperatively. Younger infants were at greater risk for this condition. 36 infants were given either placebo or simethicone, and of these, infants who received simethicone were comfortable earlier and required fewer rescue medications compared with placebo. There were no differences in ability to tolerate oral fluids prior to discharge or in the length of stay in the PACU. CONCLUSIONS: Simethicone is a safe and inexpensive medication that may provide anesthesiologists with an effective treatment choice for suspected postoperative abdominal discomfort in infants.

The FLACC: a behavioral scale for scoring postoperative pain in young children.

PURPOSE: To evaluate the reliability and validity of the FLACC Pain Assessment Tool which incorporates five categories of pain behaviors: facial expression; leg movement; activity; cry; and consolability. METHOD: Eighty-nine children aged 2 months to 7 years, (3.0 +/- 2.0 yrs.) who had undergone a variety of surgical procedures, were observed in the Post Anesthesia Care Unit (PACU). The study consisted of: 1) measuring interrater reliability; 2) testing validity by measuring changes in FLACC scores in response to administration of analgesics; and 3) comparing FLACC scores to other pain ratings. FINDINGS: The FLACC tool was found to have high interrater reliability. Preliminary evidence of validity was provided by the significant decrease in FLACC scores related to administration of analgesics. Validity was also supported by the correlation with scores assigned by the Objective Pain Scale (OPS) and nurses' global ratings of pain. CONCLUSIONS: The FLACC provides a simple framework for quantifying pain behaviors in children who may not be able to verbalize the presence or severity of pain. Our preliminary data indicates the FLACC pain assessment tool is valid and reliable.

Managing sedation in critically ill children.

Sedating critically ill children presents a challenge for even the most experienced critical care nurse. The nurse must differentiate agitation caused by pain, fear, hypoxia, or other factors and take appropriate action. This paper discusses using an algorithm to assess agitation and sedation needs and presents management options for sedation.

Effect of preemptive acetaminophen on postoperative pain scores and oral fluid intake in pediatric tonsillectomy patients.

Postoperative pain is a significant problem that continues to be undertreated in the pediatric population. Preemptive administration of analgesics has recently emerged as a method to enhance pain management associated with surgery. The purpose of this study was to compare postoperative pain scores, rescue analgesic use, and oral fluid intake in children who received acetaminophen preoperatively to children who received postoperative acetaminophen. The sample consisted of 28 children, 2-8 years of age, scheduled for elective tonsillectomy. Children were randomized into the control or the experimental groups. Anesthesia induction and maintenance were standardized. The experimental group received 15 mg/kg of oral acetaminophen preoperatively, and the control group received 20 mg/kg of rectal acetaminophen postoperatively. Pain was scored with the FLACC (faces, legs, activity, cry, consolability) behavioral assessment tool. Scores were significantly lower for the experimental group at 30 minutes after awakening and significantly lower for the control group at 240 minutes (P < .05). Eight patients (57%) in the control group and only 4 (28%) in the experimental group required rescue morphine postoperatively. Total postoperative morphine was not significantly different between groups. There were no differences in time to initial oral fluid intake and total oral fluid intake postoperatively. Incidence of nausea and vomiting was high in both groups (64-78%). These results provide evidence that preemptive acetaminophen may enhance analgesia in pediatric tonsillectomy patients. Preoperative acetaminophen is a safe, quick, and inexpensive intervention that can readily be incorporated into anesthesia practice.

Evaluation of a case management model for preanesthesia screening.

Case management (CM) is a health care model implemented to reduce health care costs while improving the quality of patient outcomes. Using a CM framework, a preoperative screening program was developed to improve the coordination of care of pediatric patients scheduled for ambulatory surgery or admission on day of procedures at C.S. Mott Children's Hospital. Pediatric patients and their families who attended the preoperative program experienced fewer preoperative delays, perceived less stress, and felt better prepared for surgery and discharge than those who did not participate in the program. Findings from this study showed that the CM preanesthesia screening program was effective in reducing delays because of incomplete workups, and in improving the overall preparedness of families.

Adverse events and risk factors associated with the sedation of children by nonanesthesiologists.

UNLABELLED: After implementation of hospital-wide monitoring standards, a quality assurance (QA) tool was prospectively completed for 1140 children (aged 2.96 +/- 3.7 yr) sedated for procedures by nonanesthesiologists. The tool captured data regarding demographics, medications used, adequacy of sedation, monitoring, adverse events, and requirement for escalated care. The medical records of children who experienced adverse events were reviewed. Most (99%) children were monitored with pulse oximetry. Chloral hydrate was the most frequently used sedative (74.9% of cases). Of the children, 239 (20.1%) experienced adverse events related to sedation, including inadequate sedation in 150 (13.2%) and decrease in oxygen saturation in 63 (5.5%). Five of these children experienced airway obstruction and two became apneic. No adverse event resulted in long-term sequelae. Of the 854 children who received chloral hydrate, 46 (5.4%) experienced decreased oxygen saturation (> or = 90% of baseline). Children experienced desaturation after the use of chloral hydrate had received the recommended doses of chloral hydrate (38-83 mg/kg). ASA physical status III or IV and age < 1 yr were predictors of increased risk of sedation-related adverse events. These data underscore the importance of appropriate monitoring that includes pulse oximetry to permit early detection of adverse events. IMPLICATIONS: This quality assurance study highlights the risks associated with the sedation of children and emphasizes the importance of appropriate monitoring by trained personnel. Children with underlying medical conditions and those who are very young are at increased risk of adverse events, which indicates that a greater degree of vigilance may be required in these patients.

Parent perceptions of pediatric ambulatory surgery: using family feedback for program evaluation.

Pediatric ambulatory surgery programs have grown tremendously during the past decade. However, limited nursing time places severe constraints on the care and education of surgical outpatients. Preoperative teaching, patient support, and postoperative instruction, previously conducted over days, is now completed in several hours. The ambulatory surgical program at Mott Children's Hospital was designed to provide thorough patient and family education, comprehensive patient care, and short-term follow-up. A formal evaluation of the program was conducted to ensure quality care for outpatients. This study evaluated preoperative and discharge preparation, postoperative problems and follow-up, preoperative waiting, stress, and privacy. The sample was composed of 332 families. Of the respondents, 289 (87%) felt very prepared overall for outpatient surgery; 33 families (10%) attended the preoperative tour, and felt significantly better prepared for surgery than families who did not attend; 322 families (97%) felt adequately prepared to very prepared for discharge; 245 families (76%) felt that the recovery time was just right; 40 parents (12%) felt that their children experienced more pain and 34 (10.4%) more nausea and vomiting than expected postoperatively; 54 families called a PACU nurse postoperatively with questions, and 92% rated the call as very helpful; 31 families called the surgical service with concerns, and 61% rated the surgeon as helpful; 83 families (25%) perceived the outpatient experience as being very stressful. Stress correlated significantly with preoperative preparation, preoperative wait, previous outpatient experience, and perceived postoperative pain. Privacy in the environment was rated as fair to poor by 192 families (59%).(ABSTRACT TRUNCATED AT 250 WORDS)

Separation and induction behaviors in children: are parents good predictors?

In busy surgical outpatient settings, it is important to quickly yet thoroughly assess a child's preoperative needs to determine whether a premedication or perhaps a parent's presence is warranted to facilitate a smooth anesthetic induction. This observational study of 252 children evaluated factors related to separation and induction behaviors of children. Six percent of children had difficulty separating from their parents, and 22% were uncooperative with induction of general anesthesia via face mask. Logistic regression showed that parent prediction was the best indicator of separation behavior, whereas younger age and separation behavior were both predictive of induction behavior. Findings suggest that parents are good predictors of their child's preoperative behaviors and may, therefore, provide valuable input when perioperative nurses and anesthesiologists are making decisions about potential preoperative interventions.

Perioperative considerations for the child with an upper respiratory tract infection.

The decision to cancel or proceed with elective surgery for the child with an upper respiratory tract infection (URI) has been a source of debate among pediatric anesthesiologists, nurse anesthetists, and perianesthesia nurses for many years. Although some studies suggest that anesthesia for the child with a URI increases the risk of perioperative respiratory complications, others suggest that these complications are easily managed and are not associated with any adverse sequelae. This article describes the pathogenesis of viral respiratory tract infections, reviews the literature regarding anesthesia and URIs, and discusses the assessment and management of the child who presents for elective surgery while harboring a URI. It is hoped that this information will be important to perianesthesia nurses and anesthesia providers in making decisions regarding proceeding or cancelling surgery for children with URIs and in optimizing their perioperative management.

Stress, coping, and quality of life in adult kidney transplant recipients.

The purpose of this study was to identify specific stressors and coping strategies identified by adult kidney transplant recipients in the first 6 months after transplantation. Quality of life was used as the outcome measure. Subscales were rationally constructed based on literature review and logic for both the stress and coping scales. Health-related items were identified as most stressful including uncertainty about whether the transplant will be a success and concern about risk of infections and/or viruses. Work-related items were least stressful. Strongly endorsed coping strategies included items on the Distancing/detachment and Self-control/accepting responsibility subscales. Quality of life scores were significantly higher after the transplant than before. Total stress was the important predictor of quality of life before transplant. Both total stress and total coping were important predictors of quality of life after transplant. The expanded transplant nursing role provides an opportunity to identify stressors and suggest appropriate coping strategies early in the transplant experience.

Stress, coping, and quality of life in family members of kidney transplant recipients.

This study explored specific stressors and identified coping strategies used by family members of kidney transplant recipients in the first 6 months following transplantation. Quality of life was also briefly examined as the outcome measure. Health-related items were identified as most stressful, and work-related items as least stressful. Self-controlling and problem-solving coping strategies were most frequently used, and escape/avoidance strategies were least used. Findings from this study have implications for development of specific teaching plans for transplant recipient families, as well as for collaborative team exploration of family stress and coping.

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

UNLABELLED: 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.