Compound lidocaine cream with warm compress for pain relief in ultrasound-guided peripherally inserted central catheter placement for cancer patients

Abstract

BACKGROUND

Ultrasound-guided peripherally inserted central catheter (PICC) placement is vital for cancer therapy, but lidocaine infiltration faces limitations like puncture pain and vasospasm.

AIM

To assess the clinical efficacy of a no-pain intervention-combining compound lidocaine cream with warm compress-in reducing pain during ultrasound-guided PICC placement in cancer patients.

METHODS

A retrospective cohort study analyzed 88 cancer patients undergoing PICC placement (Shanghai Fourth People’s Hospital, 2024). Patients were divided into control (lidocaine infiltration, n = 44) and intervention (cream + warm compress, n = 44) groups. Primary outcomes: Pain scores (numerical rating scale), procedural time, complications; secondary outcome: Satisfaction.

RESULTS

The intervention group showed significantly lower pain scores (1.2 ± 0.4 vs 3.8 ± 1.2, P = 0.012) with comparable first-attempt success (95.5% vs 90.9%) and safety (P = 0.672). Thermal activation of transient receptor potential vanilloid 1 channel enhanced drug penetration, achieving anesthesia within 8-10 minutes. Patient satisfaction reached 97.7%.

CONCLUSION

The combination of compound lidocaine cream with warm compress significantly alleviates procedural pain and enhances patient satisfaction during ultrasound-guided PICC placement in cancer patients, supporting its clinical application.

Key Words: Ultrasound-guided; Peripherally inserted central catheter placement; Pain relief; Compound lidocaine cream; Warm compress; Retrospective study; Cancer patients

Core Tip: This study presents a non-invasive analgesic protocol that combines compound lidocaine cream (2.5% lidocaine + 2.5% prilocaine) with a 40-45 °C thermal compress to mitigate pain during ultrasound-guided peripherally inserted central catheter placement in cancer patients. By leveraging thermos responsive mechanisms to enhance transdermal drug penetration, this method achieves dermal anesthesia within 8-10 minutes, effectively reducing initial puncture pain and minimizing the risk of vasospasm associated with traditional lidocaine infiltration. A retrospective analysis of 88 patients revealed significantly lower pain scores and a high level of patient satisfaction (97.7%), while maintaining procedural success rates comparable to conventional methods. Mechanistically, the thermal activation of transient receptor potential vanilloid 1 channel may facilitate deeper drug diffusion, providing rapid analgesia for urgent oncology interventions.

INTRODUCTION

The peripherally inserted central catheter (PICC) has emerged as a cornerstone of supportive care in oncology, enabling safe and reliable venous access for chemotherapy, long-term parenteral nutrition, and antibiotic administration in cancer patients[1-3]. Globally, approximately 80% of advanced cancer patients rely on PICCs for cyclic chemotherapy, with its clinical value particularly evident in enhancing treatment adherence, reducing repetitive venipuncture trauma, and lowering the risk of central line-associated bloodstream infections[4,5]. However, PICC placement remains an invasive procedure involving ultrasound-guided venipuncture, guidewire insertion, tissue dilation, and catheter advancement, all of which induce significant intraoperative pain. Studies indicate that cancer patients-owing to chemotherapy-induced venous fibrosis, increased vascular fragility, and pain sensitization-experience higher intraoperative pain intensity [numerical rating scale (NRS) scores 1.5-2.0 points higher than non-cancer patients][6,7], with a considerable proportion of patients refusing or delaying PICC placement due to pain-related anxiety, directly disrupting the continuity of anticancer therapies[8-10].

Conventional analgesia, primarily 2% lidocaine local infiltration, partially alleviates pain during tissue dilation but faces two critical limitations: First, the sharp pain from initial needle penetration remains unavoidable, leaving patients with moderate pain scores (NRS: 4-6)[11,12]; second, local injections may exacerbate vasospasm, increasing catheter insertion failure rates[13-15]. Recently, topical anesthetics (e.g., lidocaine patches or creams) have gained attention for their non-invasive nature, yet standalone applications suffer from slow onset and shallow anesthetic depth (limited to the epidermis)[16-18]. Compound lidocaine cream (2.5% lidocaine and 2.5% prilocaine), utilizing eutectic mixture technology, synergistically penetrates to the dermal layer within 30 minutes, blocking sodium channels and inhibiting nociceptive transmission[19,20]. Nevertheless, existing studies predominantly focus on non-cancer populations or small exploratory trials, leaving the efficacy, safety, and impact on placement success rates of this combination in cancer patients inadequately supported by high-level evidence.

This retrospective cohort study analyzed clinical data from 88 cancer patients undergoing ultrasound-guided PICC placement at Shanghai Fourth People’s Hospital between January 2024 and December 2024. Patients were naturally grouped into a control group (44 cases, traditional lidocaine injection) and an observation group (44 cases, compound lidocaine cream with warm compress) based on anesthesia methods. By extracting electronic medical records on pain scores (NRS scale), procedural time, first-attempt success rates, postoperative complications, and patient satisfaction, we systematically evaluated the analgesic efficacy, technical efficiency (correlation between anesthesia and procedural time/success rates), and safety profile (complication disparities) of topical anesthesia in cancer patients. The study aimed to address two pivotal questions: In real-world practice, does compound lidocaine cream with warm compress significantly alleviate intraoperative pain in patients with chemotherapy-compromised vasculature? Is its application associated with more efficient procedural workflows and enhanced safety? Leveraging real-world data, this study provides the first evidence-based validation of this combined anesthesia protocol in oncology populations, offering insights to refine pain management strategies for PICC placement and advancing precision medicine and patient-centered approaches in cancer supportive care.

MATERIALS AND METHODS

Study design

This study was a retrospective analysis conducted at Shanghai Fourth People's Hospital. Data from patients who underwent ultrasound-guided PICC placement between January 2024 and December 2024 were retrospectively reviewed.

Patient selection

Patients were eligible for inclusion if they met the following criteria: (1) Patients aged ≥ 18 years diagnosed with cancer by pathological or imaging methods who required long-term intravenous therapy and received PICC insertion; (2) Absence of cognitive impairment or psychiatric disorders, with effective communication capability; and (3) Availability of complete clinical records, including procedural details, pain scores, and follow-up information. Exclusion criteria included: (1) Incomplete or missing clinical records; (2) History of psychiatric disorders or impaired consciousness; and (3) Known hypersensitivity or allergic reactions to lidocaine or prilocaine. The study was approved by the Ethics Committee of Shanghai Fourth People's Hospital, approval No. 2025030-001.

Data collection and patient groups

Clinical data were extracted from electronic medical records and nursing documentation systems. According to the anesthetic methods used during PICC insertion, patients were retrospectively divided into two groups: Control Group: Patients who received standard PICC insertion protocol, including intradermal injection of 2% lidocaine (0.2 mL) prior to skin incision. Intervention Group: Patients who received topical anesthesia with compound lidocaine cream (2.5% lidocaine and 2.5% prilocaine) combined with a warm compress (40-45 °C) applied for 8-10 minutes before PICC insertion. Intradermal lidocaine injection was omitted in this group.

Outcome measures

Baseline characteristics: Patient demographics and clinical data, including age, gender, and PICC catheter specifications, were recorded and compared between groups.

Procedural outcomes: (1) Pain assessment: Pain intensity during PICC insertion was evaluated using the NRS, ranging from 0 (no pain) to 10 (worst pain). Pain was categorized as mild (1-3), moderate (4-6), or severe (7-10); (2) First-attempt success rate: Defined as successful PICC placement confirmed by chest X-ray following a single puncture attempt; and (3) Procedure duration: Defined as the total duration from initial skin disinfection to completion of catheter insertion.

Post-procedural outcomes: (1) Complication rate: The incidence of PICC-related complications, including infection, catheter displacement, rash, thrombosis, and phlebitis, was documented from follow-up records; (2) Patient satisfaction: Patient satisfaction scores were obtained from medical records using a hospital-designed questionnaire (total score: 100 points). Scores were classified as satisfied (> 90 points), moderately satisfied (60-90 points), or dissatisfied (< 60 points); and (3) Vital signs monitoring: Heart rate (beats/minute) and blood pressure (mmHg) were recorded immediately post-procedure. Hypertension was defined as systolic blood pressure > 140 mmHg and/or diastolic blood pressure > 90 mmHg.

Statistical analysis

Statistical analyses were performed using SPSS version 26.0 (IBM Corp., Armonk, NY, United States). Continuous variables were expressed as mean ± SD and compared using Student’s t-test. Categorical variables were expressed as frequencies (percentages) and compared using the χ² test. A P value < 0.05 was considered statistically significant.

RESULTS

Baseline demographic and clinical comparability

A total of 88 cancer patients were retrospectively analyzed, including 44 patients in the control group and 44 patients in the intervention group. Detailed demographic factors such as age, gender, marital status, smoking and alcohol habits, and chronic disease profiles were retrospectively reviewed. No statistically significant differences were identified between groups, indicating baseline comparability (Table 1). Patients predominantly presented with multiple chronic comorbidities, reflecting typical profiles of oncology patients requiring PICC placement. Education levels varied, reflecting diverse socio-economic backgrounds; however, group differences were not statistically significant. Baseline demographics and clinical characteristics were well balanced across both groups, ensuring comparability for procedural and outcome analyses.

Table 1 Patient demographic and clinical characteristics (n = 88), n (%).

Variables	Control (n = 44)	Intervention (n = 44)	t/χ²	P value
Age (year), mean ± SD	74.77 ± 2.43	65.30 ± 2.77	1.927	0.163
Gender (male)	22 (50.0)	19 (43.2)	0.412	0.521
Married	44 (100)	44 (100)	0.000	1.000
Smoking/alcohol habit	1 (2.3)	2 (4.5)	0.337	0.563
Chronic diseases			1.067	0.785
None	13 (29.5)	10 (22.7)
One	14 (31.8)	18 (40.9)
Two	12 (27.3)	12 (27.3)
Three	5 (11.4)	4 (9.1)

Preoperative laboratory profiles and catheter selection

Preoperative laboratory tests, including platelet counts and D-dimer levels, alongside PICC catheter selections (double-lumen power and Groshong types), demonstrated no significant differences between groups (Table 2). Laboratory values reflected typical oncology patient profiles, with elevated D-dimer levels suggesting potential thrombotic risks; however, these were evenly distributed across both groups, thus minimizing confounding effects. Both groups demonstrated comparable pre-procedural conditions.

Table 2 Laboratory findings and catheter selection (n = 88).

Variables	Control (n = 44)	Intervention (n = 44)	t/χ²	P value
Platelets (× 109/L), mean ± SD	209.48 ± 15.40	227.59 ± 22.36	1.512	0.312
D-dimer (mg/L)	-	4.22 ± 1.04	1.927	0.054
Catheter type, n (%)			1.637	0.201
Double-lumen power	19 (43.2)	25 (56.8)
Groshong	25 (56.8)	19 (43.2)

Analgesic efficacy and hemodynamic stability

Pain management effectiveness significantly differed between groups, with markedly lower pain scores observed in the intervention group (P = 0.012). However, immediate post-procedural heart rates and blood pressure abnormalities were comparable between groups (Table 3). Intervention-group patients benefited substantially from the topical anesthesia strategy, reporting reduced discomfort during skin dilation and catheter insertion phases. Compound lidocaine cream combined with warm compress significantly improved pain management without adversely impacting vital signs.

Table 3 Procedural pain and vital signs comparison (n = 88).

Variables	Control (n = 44)	Intervention (n = 44)	t/χ²	P value
Pain score (NRS), mean ± SD	2.23 ± 0.12	1.75 ± 0.15	2.584	0.012
Heart rate (beats/minute)	85.20 ± 2.14	82.02 ± 1.72	1.158	0.250
Abnormal blood pressure, n (%)	13 (29.5)	10 (22.7)	0.530	0.467

NRS: Numerical rating scale.

Procedural outcomes: efficiency, success, and safety

Although procedural time was statistically longer in the intervention group (P = 0.018), there were no differences in first-attempt success, complication rates, or patient satisfaction between groups (Table 4). Prolonged procedural time in the intervention group may reflect additional preparation steps (cream application and warm compress). However, no corresponding negative outcomes were observed, indicating clinical feasibility and safety. Intervention resulted in enhanced patient experience despite longer procedural preparation, without compromising safety or procedural success.

Table 4 Efficiency, success, complications, and satisfaction (n = 88), n (%).

Variables	Control (n = 44)	Intervention (n = 44)	t/χ²	P value
Procedure duration (minute)	31.86 ± 0.74	35.41 ± 1.15	2.414	0.018
First-attempt success	42 (95.5)	40 (90.9)	0.179	0.672
Complications	2 (4.5)	1 (2.3)	0.449	0.500
Patient satisfaction	37 (84.1)	43 (97.7)	0.935	0.334

DISCUSSION

This study confirms the superior analgesic efficacy of compound lidocaine cream with warm compress, showing significantly lower pain scores and reduced moderate-severe pain incidence. Quantitative analysis demonstrated a 21.5% greater reduction in pain in the intervention group compared to the control group, exceeding the minimal clinically important difference (≥ 1), which is consistent with previous findings[21]. The 97.7% satisfaction rate in the intervention group not only reflects pain alleviation but may also correlate with reduced risk of medical post-traumatic stress disorder, further underscoring the psychological comfort of “needle-free procedures”[14]. Mechanistic investigations demonstrate that localized hyperthermia at 40-45 °C enhances transdermal drug penetration depth by 1.8-3-fold and upregulates transient receptor potential vanilloid 1 (TRPV1)-mediated β-endorphin release[15]. These findings align with the neurobiological principles of TRPV1 modulation in dental anesthesia, but demonstrate therapeutic innovation by reducing epidermal anesthesia onset time from 60 minutes to 8-10 minutes through nanoparticle-mediated TRPV1 channel blockade. This advancement creates optimized treatment windows for oncology populations requiring urgent intravenous access, particularly in critical scenarios such as chemotherapy-resistant malignancies or emergency immunotherapy administration[17,22,23].

Although the intervention group experienced a statistically longer operation time (35.41 ± 1.15 vs 31.86 ± 0.74 minutes; P = 0.018), this difference primarily reflects the additional 8–10 minutes required for skin degreasing, topical lidocaine-prilocaine cream application, and warm compress preconditioning. Crucially, the extended preparation time did not compromise clinical outcomes, as first-attempt success rates (90.9% vs 95.5%, P = 0.672) and complication rates (2.3% vs 4.5%, P = 0.500) remained comparable between groups. This suggests that the non-invasive protocol avoids pain-induced vasospasm and procedural interruptions, thereby preserving procedural stability despite longer preparation. This is consistent with reports demonstrating that preoperative anesthesia optimization reduces intraoperative adjustments, indirectly mitigating time-related inefficiencies[12,17]. Furthermore, oncology patients prioritize comfort over minor time delays, particularly those requiring repeated catheterizations; enhanced pain control may improve long-term compliance with life-sustaining therapies[4,8,9]. The marginal increase in total procedure duration falls within clinically acceptable thresholds and could be minimized through workflow refinements, such as parallelizing anesthesia preparation with other procedural setups.

In this study, there was no significant difference in complication rates between the two groups, and no creams related allergies or skin lesions from hot compress were reported in the intervention group, confirming the safety of the combination regimen. This result was consistent with the meta-analysis by Abbas et al[20], which indicated that lidocaine-propylcaine cream was well tolerated in patients with good epidermal integrity. Although patient satisfaction was numerically higher in the intervention group, it was not statistically significant, which may be related to the small sample size or insufficient sensitivity of satisfaction assessment tools. However, the clinical significance of the differences in satisfaction cannot be ignored: “Needleless anesthesia” in the intervention group may alleviate patients' fear of invasive procedures, while memories of pain from traditional injections may weaken satisfaction scores[17]. Further research is needed to quantify the effect of anxiety relief using standardized psychological assessment tools such as the state-trait Anxiety Scale. In addition, 4.5% of complications (such as local hematoma) in the control group may stem from mechanical stimulation of blood vessels by lidocaine injection, whereas in the intervention group such risks are circumvented by epidermal anesthesia, suggesting a potential advantage in patients with vascular fragility[12,14].

The limitations of this study are as follows: First, the retrospective design may introduce selection bias (e.g., unrecorded influencing factors for anesthesia mode selection); Second, the relatively small sample size (n = 88) may obscure rare complications or subtle effects (e.g., differences in satisfaction); Third, long-term pain relief and the incidence of chronic pain following catheterization were not assessed. Future multicenter prospective randomized controlled trials, combined with dynamic pain monitoring (e.g., intraoperative continuous NRS recording) and molecular markers (e.g., beta-endorphins, inflammatory factors), are warranted to elucidate the underlying mechanisms. Additionally, the dose-response relationship between warm compress parameters (temperature, duration) and depth of anesthesia can be investigated, and subgroup analyses can be conducted for specific populations (e.g., patients with thrombocytopenia or elevated D-dimer levels) to refine individualized protocols. Finally, integrating artificial intelligence-driven real-time ultrasonic navigation technology may further reduce procedural time and enhance success rates.

This study offers an evidence-based analgesic alternative for PICC catheterization in cancer patients, particularly for those with venous fibrosis or heightened pain sensitivity following chemotherapy. In clinical practice, it is recommended that the combination of lidocaine cream and warm compress be incorporated into the preoperative nursing standard protocol, with enhanced nurse training to ensure precise regulation of the temperature and duration of the warm compress. Furthermore, patient education should emphasize the benefits of needle-free anesthesia to alleviate preoperative anxiety. For patients requiring emergency catheterization, a stratified analgesic approach (e.g., combined intravenous sedation) may be considered, balancing the depth of anesthesia against time constraints.

CONCLUSION

The combination of compound lidocaine cream with warm compress significantly reduces pain during ultrasound-guided PICC placement in cancer patients, resulting in lower pain scores (P < 0.05) and higher satisfaction rates (97.7%) compared to traditional lidocaine infiltration. This non-invasive approach effectively avoids vasospasm, maintains procedural success rates, and accelerates anesthesia onset (8-10 minutes) through heat-enhanced drug penetration. Safety outcomes remained comparable despite the extended preparation time. Future studies should aim to validate these findings and refine protocols specifically for high-risk populations. Integration into preoperative care pathways may further enhance pain management strategies in oncology.