Lidocaine infusions and reduced opioid consumption—Retrospective experience in pediatric hematology and oncology patients with refractory pain

Abstract

Background

Despite a more robust experience with lidocaine infusions for pain management in adults and general pediatric population, there is limited evidence of efficacy of lidocaine infusions for pain management in patients with pediatric hematology and oncology diagnoses.

Methods

Data pertaining to continuous intravenous lidocaine infusions prescribed between January 2009 and June 2019 were reviewed, including patients’ demographic characteristics, hematology/oncology and pain diagnoses, concurrent pain medications, and lidocaine infusion dose regimens and duration. Pain scores and opioid consumption calculations based on morphine equivalent doses (mg/kg/day) of patient-controlled analgesia were collected one day before infusion (D1), during infusion (D2), and one day after infusion (D3).

Results

The mean opioid consumption on D3 was significantly lower than that on D2 (p=0.01). The pain scores on D3 were significantly lower than those on D1 when measured as average pain scores per 24 hours (p<0.001) or as single pain scores immediately before and after infusions (p<0.001). No significant associations were found between cumulative doses of lidocaine (loading dose plus total infusion dose) and either a decrease in the opioid consumption or a decrease in pain scores.

Conclusions

In this retrospective series of pediatric hematology and oncology cases, we report positive outcomes in reducing opioid consumption and pain scores after lidocaine infusions. Prospective investigations designed in a collaborative, multi-institutional fashion, including a variety of pediatric populations are needed to further investigate the efficacy of lidocaine infusions.

Introduction

The most robust evidence supporting the effectiveness of lidocaine infusions for pain management is based on their use in the perioperative setting, both in adults^1–6 and in pediatrics.^7–11 Other applications for lidocaine infusions in adult pain management include chronic pain conditions,^12,13 neuropathic pain conditions,^14–18 chemotherapy-induced neuropathic pain,^19,20 cancer pain,²¹ and acute sickle cell disease-related pain.²²

In pediatric practice, lidocaine infusions have been reported in the context of acute pain entities other than perioperative use, for status migraine²³ and primary erythromelalgia,²⁴ and for chronic pain entities including chronic neuropathic pain and chronic headaches.²⁵ In pediatric oncology, the literature reporting the use of lidocaine infusions is limited to two single case reports,^26,27 a small series of 4 cases,²⁸ a commentary to the case series,²⁹ and a retrospective series of lidocaine infusions in the context of anti-GD₂ antibody therapy.³⁰ In pediatric hematology, the use of lidocaine infusions in children and adolescents with acute sickle cell disease-related pain and their opioid-sparing effect have been described in a small case series.³¹ Given the paucity of literature, we conducted this retrospective review of our institutional experience with lidocaine infusions for pediatric pain management in pediatric hematology and oncology.

Methods

The retrospective review included all continuous intravenous lidocaine infusions prescribed by the pain management service at our institution, in both inpatient and outpatient settings, between January 2009 and June 2019. Lidocaine infusions used intraoperatively, postoperatively, or both as part of the anesthetic plan or for cardiac indications in the critical care unit were excluded from the data collection and analyses.

Data collected included demographic information (age, sex, race; hematology oncology diagnosis), dosing details of the lidocaine infusions (loading dose, infusion rate, infusion duration), inpatient vs. outpatient location of administration of lidocaine infusion; concurrent medications for pain; opioid use; and pain intensity scores. The duration of lidocaine infusions was typically 4 hours or 8 hours, but the duration of infusions may have varied if side effects occurred.

Two study outcomes were evaluated as indicators of the quality of analgesia conferred by adjuvant lidocaine infusions in the context of multimodal pain management. The primary study outcome was the opioid consumption extracted from the opioid patient-controlled analgesia (PCA) data and calculated as morphine equivalent consumption (mg/kg/day) based on equianalgesic ratios between opioids. Descriptive statistics were provided to describe morphine equivalent consumption one day before infusion (D1), during infusion (D2), and one day after infusion (D3). The changes in morphine equivalent consumption (mg/kg/day) between pairs of the three time points were described and compared: that on D3 to that on D2, that on D2 to that on D1, and that on D3 to that on D1. Because individual patients could have had multiple lidocaine infusions, the Generalized Estimation Equation (GEE) method for repeated measurements was used to model the morphine equivalent consumption change between different time points. A p-value less than 0.05 was considered to be statistically significant. All the statistical analyses for this paper were generated by R Statistical Software (version 3.5.2 released on 12-20-2018).

The secondary study outcome was to compare the pain intensity scores (PS). We compared PS one day before infusion (D1), during infusion (D2), and one day after infusion (D3) to each other and compared PS immediately before initiation of lidocaine infusions to those at the conclusion of lidocaine infusions (i.e., d1= a single PS right before infusion, and d3= a single PS right after infusion). We compared the mean PS on D3 to that on D2, that on D2 to that on D1, and that on D3 to that on D1 and examined the differences for statistical significance; we also compared the single PS (d3 vs. d1). The GEE method was also applied to determine whether the changes of PS were significant.

Finally, we aimed to describe the clinical algorithm for indications for lidocaine infusions for acute and chronic pain in a pediatric population of patients with hematology and oncology diagnoses, derived from the concurrent pain medications used pre-lidocaine infusion, indicating that other lines of therapy were used before “escalating” to lidocaine infusion. Data indicating the presence of side effects or adverse reactions and any decision to stop the infusion on the basis of these events were also collected.

Results

Patient Population Characteristics

Twenty-nine patients received 78 lidocaine infusions. The patients’ demographic characteristics, primary hematology oncology diagnoses, and pain diagnoses supportive of the indication for lidocaine infusions are presented in Table 1. The distribution of infusions per patient population was 32 infusions (41%) in 12 hematology patients (41.4%) and 46 infusions (59%) in 17 oncology patients (58.6%). The median (range) number of infusions per patient was 2 (1–10). The lidocaine infusions were administered in the inpatient setting on the regular floor and in the outpatient clinic setting, for 49 and 29 infusions (62.8% and 37.2%), respectively. In a subset of 17 patients (58.6%), the pain diagnoses for which the lidocaine infusions were administered were mixed/multiple concurrent pain diagnoses of mixed nociceptive neuropathic pain; in 14 patients (48.3%), the mixed/multiple diagnoses included central sensitization, and opioid hyperalgesia in addition to mixed nociceptive neuropathic pain.

TABLE 1.

Demographic and Clinical Characteristics of 29 Patients Treated with 78 Lidocaine Infusions

Characteristic	n
Sex
Female	18
Male	11
Age (years) (median, range)
15 (3–21)
Race
Black	17
White	11
Asian and White	1
Ethnicity
Non-Spanish speaking/ Non-Hispanic	28
Puerto Rican	1
Hematology/Oncology Diagnosis a
Sickle Cell Disease	11
Leukemia/Lymphoma	12
Solid tumor	6
Factor VIII Deficiency	1
Pain Diagnosis b
Acute Nociceptive	7
Acute Neuropathic	1
Chronic Nociceptive	4
Chronic Neuropathic	1
Mixed/Multiple	17
# of Infusions (median) (range)
2 (1–10)

^a1 patient had both a solid tumor and leukemia diagnosis

^b1 patient presented for two different indications separated by 4 years

Concurrent Medications for Pain Pre-lidocaine Infusion

The concurrent medications for pain pre-lidocaine infusion included opioids in all patients and all infusions circumstances; 20 patients (69%) were treated with opioids via PCA at the time of instituting 45 lidocaine infusions (57.7%). Seventeen patients (58.6%) were treated either with a sustained release long acting opioid orally (2) or transdermally (2) or were receiving treatment with methadone (13), an intrinsically long acting opioid, at the time of their lidocaine infusions. Gabapentinoids and tricyclic antidepressants were part of the complex pain management plan at the time of lidocaine infusions initiation in 17 (58.6%) and 5 (17.2%) patients, respectively. Other lines of medication for pain included acetaminophen (10 patients, 34.5%), non-steroidal anti-inflammatory drugs (10 patients, 34.5%), lidocaine patches (8 patients, 27.6%), cyclobenzaprine (4, 13.8%), ketamine infusion (3 patients, 10.3%), epidural or intrathecal infusions (3 patients, 10.3%), and duloxetine and mexiletine in 1 patient each.

Characteristics of the Population Treated Concurrently with Opioid PCA and Lidocaine Infusions

Of the 20 patients treated with opioid PCA concurrently with 45 lidocaine infusions, data from 19 patients were included in the analyses of the opioid consumption as primary outcome, while one patient was treated in the context of end of life and displayed an outlier behavior with extremely high opioid consumption and the data was presented separately (Tables 3 and 4). To further characterize this subpopulation treated with opioid PCA, most patients (11 of 20) had diagnoses of sickle cell disease and acute pain related to vaso-occlusive crisis, while 9 patients had oncological diagnoses of leukemia/lymphoma or solid tumor. All of the hematology patients treated with lidocaine infusions in our series were receiving opioid PCA treatment as well, which reflects a standard practice of opioid PCA therapy during admissions for acute vaso-occlusive crisis, and a supplementation with lidocaine infusions.

TABLE 3.

Patient-Controlled Analgesia Opioid Consumption in 19 Patients Treated with 44 Lidocaine Infusions (mg/kg/day)^α

Time Period	Min	1st Quartile	Median	Mean	3rd Quartile	Max	N Values
D1	0.08	0.62	1.16	1.28	1.88	3.56	44
D2	0.08	0.55	1.01	1.26	1.77	3.36	44
D3	0.06	0.31	0.77	1.15	1.63	3.98	38

^α19 patients with 44 lidocaine infusions represent the subset treated with opioid PCA concurrently with lidocaine infusions

D1=day before lidocaine infusion; D2=day of lidocaine infusion; D3=day after the lidocaine infusion

For one patient, the opioid consumption data were analyzed separately from the group; in the context of end-of-life intractable pain, the morphine equivalent doses (mg/kg/day) for day before, day of, and day after the lidocaine infusion were 74.84, 177.88 and 148.15.

TABLE 4.

Comparisons of Mean Morphine Equivalent Consumption in 19 Patients Treated with 44 Lidocaine Infusions (mg/kg/day)^α

Mean Morphine Equivalent Consumption (mg/kg/day)
Time periods compared	Min	1st Quartile	Median	Mean	3rd Quartile	Max	N values	P values
D3 vs. D2	−1.51	−0.48	−0.265	−0.269	−0.095	1.4	38	0.01
D2 vs D1	−1.51	−0.26	−0.09	−0.0214	0.235	2.27	43	0.78
D# vs D1	−1.94	−0.55	−0.36	−0.214	0.1625	3	38	0.28

^α19 patients with 44 lidocaine infusions represent the subset treated with opioid PCA concurrently with lidocaine infusions

D1=day before lidocaine infusion; D2=day of lidocaine infusion; D3=day after the lidocaine infusion

Lidocaine Infusion Dosing

Based on our institutional guidelines for lidocaine infusions for pain management, the infusion has two components: 1) a loading dose of 1–2 mg/kg, over 30 minutes (may or may not be used); and 2) a continuous infusion of 1–2 mg/kg/h, not to exceed the maximum of 300 mg/h. The guidelines also allow a loading dose of 5 mg/kg over 30 minutes, not followed by an infusion. In addition to the loading dose analysis and the infusion analysis, a cumulative dose analysis was performed: loading dose (mg/kg) + (infusion dose [mg/kg/h] × number of hours) = cumulative dose (mg/kg).

The mean of loading doses in 13 infusions was 2.08 mg/kg (median, 2; range, 1.5–5); the mean of infusion rates in 77 infusions was 1.66 mg/kg/h (median, 1.5; range, 0.2–2). In one instance, lidocaine was administered as a bolus dose of 5 mg/kg over 30 minutes and not followed by an infusion. The descriptive statistics for the cumulative dose reflect a mean dose of 8.4 mg/kg (median, 8; range, 2.8–18) (Table 2).

TABLE 2.

Lidocaine Infusions Dosing Data for 29 Patients Treated with 78 Infusions^a

Measurement	Min	1st Quartile	Median	Mean	3rd Quartile	Max	Number of values
Loading Dose (mg/kg)	1.5	1.5	2	2.08	2	5	13
Infusion Rate (mg/kg/h)	0.2	1.5	1.5	1.66	2	2	77
Cumulative Dose (mg/kg)	2.8	6.0	8.0	8.4	9.5	18.0	78ª
Duration (h)	2	4	4	4.87	6	8	77ª

^aIn one instance, the bolus dose administered over 30 minutes was not followed by a continuous infusion.

Pain Outcomes

Decrease in Morphine Consumption

Opioid consumption data were available for a subset of patients treated with opioid PCA concurrently with the lidocaine infusions. Twenty patients, during 45 lidocaine infusions, were receiving treatment with opioid PCA concurrently; this subset contributed to the opioid consumption data. Of them, one patient treated with a single lidocaine infusion, in the context of intractable end-of-life pain, had vastly higher opioid consumption then the rest of the cohort; therefore, the opioid consumption for this patient is reported separately. The morphine equivalent consumption per day for the day before the lidocaine infusion (D1), the day of lidocaine infusion (D2), and the day after lidocaine infusion (D3), and the comparisons of the mean of morphine consumption (mg/kg/day) on D3 to that on D2, that on D2 to that on D1, and that on D3 to that on D1 for 19 patients treated with 44 lidocaine infusions are presented in Tables 3 and 4. The singular, end-of-life patient’s data examined separately reflected morphine consumption as follows: 74.84 mg/kg/day, 177.88 mg/kg/day, and 148.15 mg/kg/day, for D1, D2, and D3, respectively.

The mean opioid consumption per day decreased for all sets of comparisons (Table 4). We found a significant difference between the mean dose of morphine equivalent consumption on the day after infusion and that on the day of infusion (p=0.01). No significant differences were found between opioid consumption on the day of infusion and that on the day before infusion (p=0.78) or between consumption on the day after infusion and the day before infusion (p=0.28).

Decrease in Pain Score

Significant differences were found between the mean PS the day after infusion and that the day before infusion and the difference between a single PS right after infusion and one right before infusion (p< 0.001). No significant differences were found for the comparisons of PS on D3 to those on D2 or of those on D2 to those on D1 (Tables 5 and 6).

TABLE 5.

Pain Scores in 29 Patients Treated with 78 Lidocaine Infusions

Time period	Min	1st Quartile	Median	Mean	3rd Quartile	Max	N values
D1 - Average PS	1.8	5.58	7.05	6.8	8.4	10	72
d1 - Single PS	0	6	8	7.5	9	10	78
D2 - Average PS	0	5	7	6.44	8.3	10	73
d3 - Single PS	0	4.55	6.85	6.18	8	10	74
D3 - Average PS	0.1	5.13	6.4	6.07	7.4	9.3	62

D1=day before lidocaine infusion; D2=day of lidocaine infusion; D3= day after the lidocaine infusion;

d1=single PS immediate before infusion; d3=first pain score after infusion

PS (pain scores) were measured using age-appropriate pain assessment tools

TABLE 6.

Comparisons of Pain Scores in 29 Patients Treated with 78 Lidocaine Infusions

Pain Score Comparison	Min	1st Quartile	Median	Mean	3rd Quartile	Max	N values	P values
D3 vs. D2 - Average PS	−5.7	−1.38	−0.6	−0.54	0	6.3	58	0.10
D2 vs D1 - Average PS	−7.0	−1.23	−0.35	−0.33	1.03	5.2	68	0.18
D3 vs D1 - Average PS	−5.5	−2.10	−1.1	−0.98	−0.2	6.1	61	<0.001
D3 vs d1 -single PS	−8.7	−1.5	−0.9	−1.40	0.0	2.0	74	<0.001

D1=day before lidocaine infusion; D2=day of lidocaine infusion; D3= day after the lidocaine infusion; d1=single PS immediate before infusion; d3=first pain score after infusion

PS (pain scores) were measured using age-appropriate pain assessment tools

Decrease in Morphine Consumption and Decrease in Pain Score versus Cumulative Doses of Lidocaine

We examined if there was a trend between the amount of the cumulative doses of lidocaine and the 2 outcomes (decrease in morphine consumption and decrease in pain score), expecting that higher cumulative doses would be associated with higher delta between D3 and D2, D3 and D1, and D2 and D1 for decrease in morphine consumption and decrease in pain score, as well as the delta between d3 and d1 for the single pain score comparisons. We did not find any significant associations between the cumulative lidocaine doses and either a decrease in morphine consumption or a decrease in pain score.

Complications and Side Effects of Lidocaine Infusions

One patient experienced orthostatic hypotension during the lidocaine infusion and required discontinuation of the infusion, transfer to the ICU, and treatment with a fluid bolus and a brief epinephrine infusion at 0.04 mcg/kg/min, weaned off within an hour. No neurologic complications were noted. Contributing factors may have included a history of hypothyroidism (on replacement therapy) and an elevated BMI (which may have led to an actual overdosing as compared to dosing based on ideal body mass).

Discussion

This retrospective investigation of 29 pediatric patients with hematology/oncology diagnoses who were treated with 78 lidocaine infusions focused on evaluations of two pain outcome measures: opioid consumption as morphine equivalent doses (mg/kg/day) and PS. The opioid consumption data reflect a robust outcome of statistically significant reduction in the use of opioid from the PCA between the day after the lidocaine infusion and the day of infusion. The results suggest that the lidocaine infusion effectively reduces the use of opioids in a self-titrated manner not only during the (usually 8 hours) of infusion but also during the subsequent day, indicating a longer-lasting effect than the actual time window of the infusion. A time-sustained effect of lidocaine infusions exceeding the actual duration of infusion has been noted in the literature.^25,33

The successful use of systemic lidocaine for neuropathic pain and non-neuropathic pain conditions such as post-operative³² and sickle cell disease-related pain³¹ have been documented. To further advance these findings, our study’s indication of beneficial effects for pain management extending beyond the duration of the lidocaine infusion may support a role for lidocaine infusions in the treatment of complex pain conditions. Two observations generated from our series can direct the clinicians toward an understanding of a clinical decision algorithm for the role and timing of lidocaine infusions. Firstly, the pain diagnoses leading the clinicians toward a decision to treat with lidocaine infusions were mixed/multiple concurrent pain diagnoses of mixed nociceptive neuropathic pain in the majority of patients and also included central sensitization and opioid hyperalgesia in addition to mixed nociceptive neuropathic pain in almost half of the patients. Secondly, the multiple lines of pain therapy options noted in our series, already in place when the lidocaine infusions are administered (opioids, either by PCA or by long acting opioid options, including methadone, gabapentinoids, antidepressants, etc.), are highly suggestive of multiple lines of therapy being “exhausted” before turning to the lidocaine infusions option. Both these observations may lead the clinicians to consider the role of lidocaine infusions as an option to treat the entity recently described by the International Association for the Study of Pain as “nociplastic pain.”³⁴ Nociplastic pain arises from altered nociception, in the absence of clear evidence of actual or threatened tissue damage or disease or lesion of the somatosensory system. It is generally characterized by allodynia, hyperalgesia, and spontaneous pain, rendering it difficult to distinguish clinically from central sensitization or secondary hyperalgesia related to ongoing pain or opioids. These central mechanisms appear to be mediated, at least partially, by NMDA receptors at the spinal cord level.³⁵ Lidocaine’s primary mechanism of action is sodium channel blockade though local anesthetics are thought to have multiple mechanisms and sites of action, most notably the NMDA receptor.^36,37 Local anesthetics’ mechanism of dose-dependent inhibition of the NMDA receptor may explain lidocaine’s ability to successfully address nociplastic pain³⁸ and to provide analgesia beyond the length of the infusion via downregulation of pain transmission pathways.

Utilizing agents that have an opioid-sparing effect while addressing multiple types of pain is a crucial approach to the success of complex pain treatment regimens. Not surprisingly, our findings indicate that the opioid consumption reduction data were more robust than the PS reduction data. The differences in PS were statistically significant only for comparisons between D3 and D1 and between d3 and d1, but no significant differences were found for the comparisons of D3 to D2 or those of D2 to D1. The PS data still suggest improvement in pain control. The pain literature suggests that the more effective measurement of improvement in pain control may come not from PS themselves but from functional outcomes, such as activities of daily living, physical activities, quality of life, quality of sleep, and level of interference of pain with general performance. Our study did not investigate any of these functional outcomes.

Another study limitation may be presented by the heterogeneity of the study population, including both hematology and oncology populations. One may observe that the pain trajectory may be vastly different between patients with oncology diagnoses and patients with vaso-occlusive crisis-related pain, for example. The oncology diagnoses may be associated with a variety of pain syndromes, and sometimes may include patients with intractable pain at the end-of-life, with massive consumption of opioids and variable effect from multiple complex interventions for pain. Contrary to the vast variability in the pain trajectories of patients with cancer, the course of vaso-occlusive crisis pain is more predictable and usually limited in time.

Comparing our study’s results to the limited pre-existent literature reflecting the clinical utility of lidocaine infusions in pediatric hematology and oncology draws attention to the strengths of our study, which include the unique study design based on 2 concurrent pain outcome measures (opioid consumption and PS) and the large number of patients and infusions. Citations of lidocaine infusions in pediatric hematology and oncology are limited to case reports and case series in a total of fewer than 20 patients.

The PS reduction noted in our study is supported by other studies of lidocaine infusions in the pediatric hematology/oncology population. A case series of patients 8 to 18 years old with opioid-refractory cancer pain found that PS significantly decreased from a median of 8/10 to 2/10 at the termination of the lidocaine infusion.²⁸ This is similar to the reduction in PS observed in our study on the day following the lidocaine infusion as compared to the day prior to the lidocaine infusion.

The opioid-sparing effects of lidocaine infusions, which were noted in our retrospective review, are also supported by several previous publications. On the basis of work from our institution, Puri et al. reported that opioid use was lower when lidocaine infusions were administered to patients admitted with vaso-occlusive crisis-related pain than in previous control admissions during which pain was treated with opioids only.³¹ Similarly, a retrospective review of five pediatric patients receiving lidocaine infusions for anti-GD₂ therapy–related pain showed significantly lower daily morphine requirements and greater mobility as compared to their previous anti-GD₂ therapy courses during which lidocaine was not administered; this represented the first clinical report suggesting the opioid-sparing effect of lidocaine infusions and the benefit to the pediatric oncology population.³⁰

Though the literature supporting the use of lidocaine infusions in the pediatric population is limited, the practice appears to be safe and well-tolerated. Although there have been reports of a high incidence of side effects (i.e., dizziness, drowsiness), these have mostly been mild and easily rectified.²⁵ Serious side effects are rare. In our series, in a single case of orthostatic hypotension during lidocaine infusion, which required interventions, contributing factors may have included hypothyroidism and an elevated BMI which may have led to an actual overdosing as compared to dosing based on ideal body mass.

Demonstration of the safety and tolerability of lidocaine infusions is important, as access to this therapy in many institutions is restricted to inpatients, and possibly to the ICU setting. However, some conditions for which lidocaine infusion may be helpful, vaso-occlusive crises pain in patients with SCD specifically, can be treated in the outpatient setting and can spare hospital resources. In our experience outpatient lidocaine infusions are safe and well-tolerated (29 outpatient lidocaine infusions in this study, representing over one third of the infusions, without need for hospital admission). Of note, in our series, as well as in other reports,²⁵ the first lidocaine infusion is administered as inpatient (in our setting, on the regular floor), followed by subsequent infusions (if needed) in the outpatient clinic setting. This approach allows us to closely monitor both for clinical efficacy for pain and for side effects and toxicity, during the first infusion, and to decide regarding the indication for subsequent infusions. When infusions are administered in the clinic setting, which can be administered daily until the pain source resolves, the same set of institutional guidelines are applied, regarding clinical monitoring and as needed laboratory monitoring. A publication by Massey and colleagues further confirms that a lidocaine infusion may be considered for home administration.²⁶ The patient described in this case report was an end-of-life pediatric oncology patient discharged home on a lidocaine infusion two months prior to death and experienced no untoward effects due to the lidocaine infusion. Administering lidocaine infusions in an outpatient setting spares hospital resources and ensures an opportunity for end-of-life care at home in the final days of life, if preferred. In our experience, the presence of an institutional policy/guideline, continuous nursing education, and protocol-based dosing are crucial to safely administer lidocaine infusions in the outpatient setting.

The dosing and administration schedules of lidocaine infusions reported in the literature vary considerably. The practice of lidocaine bolus administration prior to the infusion contributes to this variability. As previously described in the literature,^{7,8,23,28,30,31} and consistent with our institutional practice, a bolus may be administered prior to the lidocaine infusion to assess the patient’s response and to establish a clinically effective lidocaine plasma level. In our practice, the decision to administer a bolus prior to the infusion is at the discretion of the pain management clinician and is based on patient-specific considerations. Several pediatric publications have also reported initiating a lidocaine infusion without a bolus dose.^10,24–27 Although the dosing of lidocaine boluses is well below doses that are concerning for toxicities, higher rates of lidocaine infusion are more commonly associated with side effects and adverse reactions. This risk should be considered when determining whether to administer a bolus prior to the lidocaine infusion.

In this retrospective series of pediatric hematology and oncology cases, we report positive outcomes in reducing opioid consumption and pain scores during and after lidocaine infusions. More robust prospective investigations would be best designed in a collaborative, multi-institutional fashion, to include a variety of pediatric populations and larger samples of patients and to address specifically the question of which patient populations may benefit the most from intravenous lidocaine infusions for pain management.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.