What do we know about this topic?

What is the contribution of this study?

INTRODUCTION

Morbidity and mortality associated with pediatric anesthesia has dropped dramatically over the past decade ^1,2. However, post-anesthetic respiratory complications continue to be a source of concern due to their high frequency ³. Major complications - critical or serious events requiring immediate intervention - are a priority, given that they can result in disability or death ^4,5.

Risk factors for major complications which can be identified during the pre-anesthesia assessment have been described ⁶ and include patient characteristics, surgery-related characteristics and, finally, the experience of the anesthetist or of the post-anesthesia care unit (PACU) staff ³.

In pediatrics, the incidence of any major complication is described to be as high as 5.2% ⁵; however an important proportion is considered preventable ⁷. Most perioperartive complications in the pediatric population have been observed during anesthesia induction and in the PACU ⁶. Knowledge of the risk factors for major respiratory complications during PACU stay is highly relevant.

In pediatric patients, care for the airway in the PACU has been entrusted to trained nurses in several institutions throughout the world, with results that show that this is an efficient strategy when complications and length of stay are measured ⁸.

The objective of this study is to describe the incidence of respiratory complications during a six-month period in the PACU of an intermediate complexity center with a nursing-based recovery model, exploring the variables associated with major respiratory complications.

METHODS

Retrospective, historical cohort study. Data were taken from PACU records of an intermediate complexity pediatric center located in Medellin, Colombia, between April and October, 2017.

Fundación Clínica Noel is an intermediate complexity center that serves the pediatric population in Medellin, Colombia. A model of nursing-based patient care in the PACU has been developed over the past few years. Care is provided by licensed practical nurses (LPN) who receive intensive training in airway management and anesthesia emergence in pediatric patients, with a 1:1 nurse-to-patient ratio. LPNs are responsible for removing the airway device used during the surgical procedure and to respond to any complication, with the continuous support of the anesthetist who provided the anesthesia.

The clinical records of all patients under 16 years of age who were taken to surgery and received post-anesthesia care in the institution during the study period were reviewed.

The primary outcome was major respiratory complications in the PACU (laryngospasm, bronchospasm, respiratory depression, cardiac arrest and acute pulmonary edema ⁵. Minor respiratory complications were also reviewed: stridor, persistent loud coughing, presence of pharyngeal plug at the end of the procedure, airway bleeding and residual muscle relaxation. Demographic characteristics, patient background history and intra-operative variables such as surgery type and airway management were assessed.

STATISTICAL ANALYSIS

Frequency and percentages were used for categorical variables and medians and inter-quartile ranges (IQR) for quantitative variables for the descriptive analysis of patient characteristics and surgical and anesthetic management. The cumulative incidence of major and minor complications is reported.

A binary logistic regression model was used for the exploratory analysis of factors associated with complications. Estimates adjusted by OR and 95% CI are described. A value of p ≤ 0.05 was established as significant.

To add to the analysis, taking into account lengths of stay in the PACU, incidence rates ofmajor complications were estimated and associations were calculated using a generalized linear regression with Poisson family and logarithmic link. Crude and adjusted estimates are presented using incidence rate ratios with 95% CI.

The Stata^® versión 12 (StataCorp) software was used for the analysis.

RESULTS

Overall, 1314 patients under 16 years of age admitted to the PACU were included. Of them, 133 were excluded because of more than 20% missing data. Records of 1181 patients were analyzed. Median age was 4 years (IQR 2-8); 69.09% were males (Table 1).

DISCUSSION

Extubation in the PACU by trained nursing staff is not new. The Michigan Children's Hospital has 30 years of experience using a model in which registered nurses with a minimum experience of two years in the pediatric intensive care unit and two months of training under the supervision of experienced nurses and anesthetists provide care in the PACU, including extubation, without compromising patient safety and with more efficient time management ⁹.

At Clínica Noel, the nursing staff receives specific training for recovery care and they have more than 20 years of experience in post-anesthesia care (including airway device removal) of pediatric patients. One of the biggest strengths of these models is the 1:1 nurse-to-patient ratio in the PACU. There are no reports in the literature regarding the frequency of complications with this care model, although there are reports of variation in terms of the type of training of the staff and the level of autonomy in the PACU.

One of the benefits of extubation in the PACU is a more efficient turnaround time in the operating room ⁸. Kako et al. compared total time in the operating room of pediatric patients extubated in the room, as compared to those who were extubated in the PACU, and found an average reduction of 17 minutes in the latter, showing increased efficiency ¹⁰.

This study found that despite not being a method commonly used in our setting, the total frequency of major respiratory complications was 2.7%. When compared to a conventional care model like the one described in the APRICOT trial (bronchospasm 4.0% and laryngospasm 3.2%), there was no increase in the frequency of major respiratory complications ⁵.

The study by Mamie, also involving a traditional model, reported a 12.8% incidence of respiratory complications, although less complication categories were evaluated. The study concluded that respiratory complications had more to do with anesthetic than with patient background history ¹¹.

The low frequency of respiratory complications in patients taken to the PACU with the endotracheal tube in place could be explained by the lower need for rushing awakening in order to comply with the operating room schedule. This allows to have an adequate emergence plane at the time of removing the device ¹².

Recovery of airway reflexes is aided by sympathetic nervous system activation during awakening after anesthesia. This is one of the physiological basis for extubating once the patients are fully awake ^13,14. Likewise, transfer to the PACU with the patient on an airway device should occur while the patient is in one of the planes previously mentioned ¹⁵.

On the other hand, staff experienced in pediatric care and a 1:1 care model ensure safe care. Several authors have emphasized that training in pediatric anesthesia is critical for the correct development of surgical procedures and perioperative care ^16-18.

In Colombia, Echeverry highlighted the importance of having highly competent and qualified staff and providing ongoing training for the development not only of psychomotor skills but also of soft skills such as teamwork, in order to ensure comprehensive care to pediatric patients in accordance with good quality and safety standards ¹⁹.

The search for factors associated with respiratory complications showed that bronchospasm is associated with a history of ARI less than 15 days before the procedure, age under 1 year and female sex. These results support the decision to cancel procedures on the grounds of recent ARI ²⁰. They are also consistent with other studies that show an association between age and the development of bronchospasm ²¹.

Respiratory depression was associated with a history of rhinitis, which has been found to be a risk factor for obstructive sleep apnea. This mechanism could explain airway obstruction and depression in pediatric patients, although further studies that clarify that relationship are needed ²².

Although there were no significant differences in the risk of respiratory complications with the use of cuffed or uncuffed OTT, evidence shows that the use of the former did not increase the risk of post-extubation stridor and, on the contrary, it reduced the number of device exchanges when compared with the uncuffed OTT ²³. Shi et al. are currently conducting a meta-analysis to compare post-extubation morbidity with the use of cuffed or uncuffed OTT, which may provide relevant information regarding this issue ²⁴.

The study by Shi et al. did not show a relationship between any of the variables analyzed and the development of laryngospasm. However, the literature suggests that this complication is associated with a superficial anesthetic plane and tachycardia. In terms of the placement of airway devices, a meta-analysis published by Luce et al. concluded that the use of LM in pediatric anesthesia reduces the incidence of this complication ^24-26.

A trend towards a higher risk of respiratory complications in the PACU was found in patients with a prior history of disease conditions. This is consistent with the findings in a retrospective cohort of 1547 patients with a history of asthma of a 1.3% incidence of bronchospasm and a 0.13% incidence of laryngospasm, and no patients with respiratory depression ²⁷.

A model of care in the PACU like the one described in this paper highlights the importance of adequate staffing for perioperative care, both in terms of numbers but also in terms of skills and experience. In such a model, the anesthetist plays a key role as the person responsible for supervised care management in a setting traditionally considered as prone to the occurrence of adverse events. The information derived from this study is relevant and timely at a time when patient safety is even more relevant.

This research includes a substantial number of patients, particularly when compared to other studies. The associations described correspond to an exploratory but not a causal analysis given that this was not its main objective and a sample size for that purpose was not calculated. Estimates must be taken with caution, bearing in mind that intraoperative variables such as drugs, which can be related to complications in the PACU, were not included. The historical nature of the research creates certain limitations derived from the quality of the entries in the clinical record; however, original records were assessed for completeness of the information, with 10.1% of the records being excluded because of missing data. The researchers believe that, in view of the paucity of information regarding this topic, a historial design provides relevant information that can serve as a basis for future prospective studies.

The frequencies of the complications described correspond to an intermediate complexity center; the operation of this PACU care model in other settings such as emergency or high complexity procedures, could differ. Further studies are required in those settings in which demands may result in different requirements for care in the PACU.

CONCLUSION

In this cohort of pediatric patients, care provided by nursing staff trained in anesthesia recovery and pediatric airway management resulted in a low frequency of respiratory complications in the PACU. This strategy could be implemented in other similar centers in the country with the aim of optimizing operating room time and resources without compromising patient safety. Likewise, improvement of psychomotor skills and continuing education must be the responsibility of all the people working in services where pediatric procedures are performed. It is important to insist on the need to identify preventable factors that could result in postoperative respiratory complications.

ACKNOWLEDGEMENTS