Pediatric sedation in vascular malformations interventions by a non-anesthesiologist—feasibility and safety

Abstract

Objective:

Sedation for pediatric patients undergoing interventional procedures in radiology is in increasing demand. Once only anesthesiology-performed, there is a demand for sedation services to perform sedations for these procedures. However, the safety of performing long sedations by non-anesthesiologists in interventional radiology has not been reported. This pilot study aimed at describing a single center's experience and outcome with sedation.

Methods:

This study reviews the sedations performed at a single center by a pediatric emergency physician who performed the sedation. The results regarding safety and satisfaction were reviewed.

Results:

A total of 52 sedations were documented. Four cases of significant adverse events and three adverse events occurred. In all cases, the procedures were completed. None of the patients required intubation or admission following the sedation. There was high satisfaction by the interventional radiologists.

Conclusion:

This small pilot study shows that sedations for procedures in interventional radiology can be performed safely and successfully by dedicated non-anesthesiology sedation services. This may be considered as an alternative when anesthesiology service is not available.

Advances in knowledge:

This small, single center pilot study examines the safety of sedation by a non-anesthesiologist for interventional radiology procedures. This may offer an additional method of performing procedures in the pediatric population while anesthesia is not readily available.

Introduction

Procedures in the interventional radiology (IR) unit are increasingly performed on pediatric patients. Adequate sedation and analgesia are necessary for successful procedural performance as well as to avoid unnecessary stress and suffering of the patient.

The availability of general anesthesia is often limited, and there are many centers performing IR procedures with sedation. Sedation in IR has already been suggested¹ using ketamine and has later been described with ketamine-propofol combinations.^2,3 In non-interventional radiology units, there are procedures being performed with nurse-administered sedation.⁴ In these cases, the sedation is performed by the anesthesiology team. The use of sedation would possibly enable faster recovery times and less occupancy of the IR suite per case.

Pediatric sedation services, staffed by emergency physicians and intensivists as well as anesthesiologists have become normative practice in many centers. In the reports from the pediatric sedation research consortium (PSRC) as early as 2009, there were 49,805 sedations reported of which only 5117 (10.3%) were performed by anesthesiologists.⁵ The latest report from 2017 shows an even lower percentage of anesthesia-provided sedation (2.2%) outside the OR.⁶ The available data today from many reports as well as databases such as the PSRC have shown that sedation by appropriately trained non-anesthesiologists can be performed safely and successfully. Adverse events are described in approximately 10% of cases. In effect, this is the standard of care in many centers..^7–10 Following many studies, adverse events are now reported based on universally accepted severity levels to assess the safety of these procedures

Our nationwide referral center for vascular malformations has seen a sharp rise in procedural volume, leading to a rise in need for anesthesiology/sedation time. In our medical center, the sedation services for pediatrics are largely supplied by the pediatric emergency physicians. Collaboration with the pediatric emergency medicine sedation providers was thus initiated. The pediatric emergency physicians (PEP) already perform a significant portion of sedations in the pediatric wing of the hospital, including in the radiology department. Their service is used frequently and successfully in a wide range of procedures throughout the hospital. We explored the feasibility and safety of extending this service to pediatric vascular malformation procedures.

In this study, we report the outcomes of these procedures over a period of a year regarding patient safety as assessed by adverse events, successful completion of procedure, and satisfaction by the interventional radiologist.

Methods

A retrospective cohort of all patients undergoing sedation by a single emergency physician in the IR unit from March 2016 to September 2017. Information collected included patient demographics, medications administered, adverse events, successful completion of procedure, and satisfaction of the treating interventional radiologist.

Patients selection was based on several parameters:

• Lesion site to be treated—only those with no airway involvement. Low flow lesions.

• Medical History—American Society of Anesthesia score under 3. No known previous adverse event with anesthetics.

• Procedures—expected simple and easy access to lesions. Several Sclerosants were used without prior consideration.

The sedation medication protocol was preformed based on the providing physicians decision per case.

All procedures were performed in the general interventional radiology unit.

Adverse events were defined by the PSRCs definitions that differentiate adverse events (AEs) from serious adverse events (SAEs) (Table 1). This is based on the Quebec guidelines.¹¹ However, as this was a pilot study a stricter definition was taken in each case. For example, hypoxic events are defined by the PSRC as those lasting longer than 30 s. In this study, hypoxia of any duration was defined as an adverse event.

Table 1.

AEs and SAEs classification (PSRC)

(AEs	SAEs
Desaturation > 30 s	Airway obstruction
Apnea > 30 s	Emergent airway
Heart rate or blood pressure change	Laryngospasm
Vomiting	Admission
Agitation	Need for ICU
Wheezing	Aspiration
Not completed procedure	Cardiac arrest/Death

AE, adverse event; PSRC, pediatric sedation research consortium; SAE, serious adverse events.

The study was approved by the hospital ethics board (0189–17-SZMC).

The results were compiled on excel sheets (Microsoft ltd.). Statistical analysis was performed using SPSS v. 21.0 (Statistical Package for Social Science, Chicago, IL).

Results

The study included 52 procedures performed on 41 children from March 2016 to September 2017. (Table 2). Patient age ranged from 4 months to 17 years. The procedures included lymphatic and venous malformations (36/16 respectively) from various areas (Table 3).

Table 2.

Patient demographics

Number of patients/cases	41/52
Age, mean (SD)	8.5 years ( ± 5.5)
Gender male/female	30/22
Weight, mean (SD) Kg	28.7 ( ± 16.6)
Fasting time, mean (SD) hours	5.9 ( ± 0.4)

SD, standard deviation.

Table 3.

Vascular malformations treated

Number of cases	Anatomic location	Type of malformation	Adverse event (n)
4	Lips	Venous
9	Neck	7 Lymphatic/2 neck	3
1	Facial	Lymphatic
1	Shoulder	Venous
8	Forearm/Elbow	Six venous/ two lymphatic
2	Paraspinal	Venous	1
4	Abdominal wall	Lymphatic
4	Thigh	Venous
5	Knee	Venous	1
7	Ankle	Five venous/two lymphatic
3	Foot	Venous	2
1	Eye lid	Lymphatic
1	Genitalia (Labia)	Venous
2	Buttock	Venous

The majority of sedations were based on a combination of ketamine and propofol with midazolam used infrequently. The sedations were relatively long (mean 44 min). The sedation was given as bed side-boluses as needed. No airway devices were used (i.e. laryngeal mask or intubation) (Table 4).

Table 4.

Sedation results

Length of sedation, minutes (SD)	44.2 (12.0)
Ketamine mg/kg, mean (SD)	1.7 (0.84)
Propofol mg/kg, mean (SD)	3.7 (2.1)
Midazolam mg/kg, mean (SD)	0.13 (0.04)

SD, standard deviation.

There were four SAEs reported and three AEs. The serious events were hypoxia³ or apneas¹ that required short bag valve mask use with a rapid return of spontaneous breathing and normal saturation. The adverse events were short hypoxic events requiring minimal airway changes. The neck region was the most common site to involve any type of adverse event (3/7). No cases required intubation, admission or incompletion of the procedure (Table 5).

Table 5.

Adverse events in IR sedations

Case	Age (years)	Weight (kg)	Procedure area	Event	Intervention	Completion of procedure
SAE 1	0.4	7.6	Neck	Desaturation	BVM X3	yes
SAE 2	4	16	Neck	Desaturation	BVM X5	yes
SAE 3	17	51	Foot	Desaturation	Oxygen reservoir	yes
SAE 4	3.5	13.5	Knee	Apnea	BVM X3	yes
AE 1	2.5	12	Spinal	Desaturation	AW maneuver	yes
AE 2	8	25	Neck	Desaturation	Oxygen supplementation	yes
AE 3	2	18	Foot	Desaturation	AW maneuver	yes

AE, adverse event; BVM, bag valve mask; SAE, serious adverse event.

All procedures were completed successfully and the performing interventional radiologist expressed high satisfaction (mean score of 5) with the sedation protocol in all procedures. (a likert score-based questionnaire: 1, unsatisfactory; 2, partially unsatisfactory; 3, neutral; 4, satisfactory; 5, very satisfactory).

Discussion

In this study, we examined the safety of sedation performed by a dedicated pediatric emergency physician in the IR setting, specifically for treatment of vascular malformations. Sedation in IR has been previously reported only by anesthesiologists. As the availability of anesthesia continues to be a challenge, the use of sedation by a non-anesthesiologist may be an alternative when needed.

The sedation times in this study were relatively long (mean 44 min) compared to shorter procedures usually encountered in the emergency department (fracture reduction, suturing etc.). It is standard to consider the mean sedation time in the ED approximately 20 min with procedures over 30 min considered long. With a comparable number of AEs, this stresses the safety of these procedures.

The number of AEs and SAEs is slightly higher than previous reports from sedations outside the operating room (13.4% vs 9.8%). Based on strict PSRC definitions, there were only three true AEs. In this study, SAEs and AEs included any airway interventions to err to the side of caution. The emergent airway cases were either short bag-mask use (three cases) or need for oxygen mask (one case). All of these cases would not be considered a true “emergent airway” based on PSRC definitions. The neck region was the area most commonly associated with an adverse event (3 of 7). Although without sequalae this may be a consideration in future case selection. All the AEs and SAEs were short lived and none of the cases with an AE reported require prolonged observation or any further follow up compared to those without an AE.

The findings of this study show that safe sedations that are considerably longer than emergency department sedations can be performed by PEPs with no significant incidence of adverse events. These were performed in a new setting and with high satisfaction by the treating physician. The use of sedation enables faster scheduling of procedures, shorter recovery and length of stay. It is likely more cost effective than general anesthesia, although this was not assessed directly in this study. Although anesthesia-based sedation should be the first option, there may be room for sedation by non-anesthesiologists in selected cases.

This study is limited by a relatively small sample size, retrospective design, and by its single center nature. Prospective comparison of safety, overall procedure room time, performing physician satisfaction, as well as continued reporting to central databases such as the Society of Pediatric Sedation and others are recommended.