Continuous Subcutaneous Infusion: An Efficacious, Cost-Effective Analgesia Alternative at the End of Life

Pediatric Palliative Care at Home: A Prospective Study on Subcutaneous Drug Administration

CONTEXT

The subcutaneous route is a useful alternative for drug administration in palliative care. Although there is scientific evidence on its use in adult patients, the literature in pediatric palliative care is almost nonexistent.

OBJECTIVES

To describe the experience of a pediatric palliative care unit (PPCU) with in-home subcutaneous drug administration symptom control.

METHODS

Prospective observational study of patients receiving home-based subcutaneous treatment administered as part of a PPCU treatment regimen over 16 months. Analysis includes demographic and clinical variables and treatment received.

RESULTS

Fifty-four different subcutaneous lines were inserted in the 15 patients included, mainly in the thigh (85.2%). The median time of needle in situ was 5.5 days (range: 1-36 days). A single drug was administered in 55.7% of treatments. The most frequently used drugs were morphine chloride (82%) and midazolam (55.7%). Continuous subcutaneous infusion was the predominant administration route (96.7%), with infusion rates oscillating between 0.1 mL/h and 1.5 mL/h. A statistically significant relationship was found between the maximum infusion rate and induration onset. Of the 54 lines placed, 29 (53.7%) had an associated complication requiring line removal. The primary cause for removal was insertion-site induration (46.3%). Subcutaneous lines were mainly used to manage pain, dyspnea, and epileptic seizures.

CONCLUSION

In the pediatric palliative care patients studied, the subcutaneous route is most frequently used for administering morphine and midazolam in continuous infusion. The main complication was induration, especially with longer dwell times or higher infusion rates. However, further studies are required to optimize management and prevent complications.

Subcutaneous Administration of Medications and Fluids by Nonprofessional Caregivers at Home

Background: Patients requiring home-based palliative care have advanced complex illnesses with functional limitations and decline. This retrospective study reviewed caregiver administration of subcutaneous (SQ) medications and fluids when symptom control could not be achieved using the oral route. Methods: Medical records from September 1, 2017 to February 28, 2018 were reviewed for 272 consecutive patients who received SQ administration of medications or fluids at a home-based palliative care program. We analyzed the clinical characteristics of patients and caregivers, medications administered, and catheter outcomes. Results: Patients' median age was 74 years, and 163 (60%) were women. The most common cancer diagnoses were stomach 26 (12%), lung 22 (10%), and colorectal 20 (9%). Dementia 24 (44%), cerebrovascular disease 9 (16%), and congestive heart failure 7 (13%) were the most frequent nonmalignant diseases. Poor symptom control 162 (60%) and impaired oral intake 107 (39%) were the most common indications for an SQ route of administration. Nonprofessional caregivers trained by a nurse administered medications to 218 patients (80%). During interventions, the patients received a mean of 4 medications (±2 standard deviation). A total of 903 catheters were inserted, 15/732 (2%) catheters handled by nonprofessional caregivers caused a local infection, compared with 3/171 (1.8%) of catheters handled by nurses. Hydromorphone was the most common opioid used (57%), followed by morphine (35%). The median length of stay in the program was 24 days (interquartile range: 11-60). Conclusions: SQ administration of medications and fluids by nonprofessional caregivers trained by health care professionals is feasible and promising, but additional testing is needed.

The development and evaluation of a subcutaneous infusion delivery system based on osmotic pump control and gas drive

A novel, self-administration drug delivery system for subcutaneous infusion was developed and evaluated. The device includes two main components: an osmotic tablet controlled gas actuator and a syringe catheter system. The sodium carbonate in the osmotic pump tablet will release into the surround citric acid solution and produce CO₂ gas, which will drive the drug solution into subcutaneous tissue. The key formulation factors of the osmotic tablet that would influence the infusion profiles of the device were investigated by single factor exploration. The formulation was optimized via a response surface methodology. With an 18 ± 4 min of lag time, the delivery system was able to infuse at an approximate zero-order up to 5.90 ± 0.37 h with a precision of 9.0% RSD (n = 6). A linear correlation was found for the infusion profile and the fitting equation was Y = 0.014X - 0.004 (r = 0.998). A temperature change of 4 °C was found to modify the flow rate by about 12.0%. In vivo results demonstrated that the present subcutaneous infusion device was similar to the commercial infusion pump, and it could bring a long and constant ampicillin plasma level with minimized fluctuations.

Understanding Subcutaneous Tissue Pressure for Engineering Injection Devices for Large-Volume Protein Delivery

Subcutaneous injection allows for self-administration of monoclonal antibodies using prefilled syringes, autoinjectors, and on-body injector devices. However, subcutaneous injections are typically limited to 1 mL due to concerns of injection pain from volume, viscosity, and formulation characteristics. Back pressure can serve as an indicator for changes in subcutaneous mechanical properties leading to pain during injection. The purpose of this study was to investigate subcutaneous pressures and injection site reactions as a function of injection volume and flow rate. A pressure sensor in the fluid path recorded subcutaneous pressures in the abdomen of Yorkshire swine. The subcutaneous tissue accommodates large-volume injections and with little back pressure as long as low flow rates are used. A 1 mL injection in 10 seconds (360 mL/h flow rate) generated a pressure of 24.0 ± 3.4 kPa, whereas 10 mL delivered in 10 minutes (60 mL/h flow rate) generated a pressure of 7.4 ± 7.8 kPa. After the injection, the pressure decays to 0 over several seconds. The subcutaneous pressures and mechanical strain increased with increasing flow rate but not increasing dose volume. These data are useful for the design of injection devices to mitigate back pressure and pain during subcutaneous large-volume injection.

Treatment with subcutaneous and transdermal fentanyl: results from a population pharmacokinetic study in cancer patients

Purpose

Transdermal fentanyl is effective for the treatment of moderate to severe cancer-related pain but is unsuitable for fast titration. In this setting, continuous subcutaneous fentanyl may be used. As data on the pharmacokinetics of continuous subcutaneous fentanyl are lacking, we studied the pharmacokinetics of subcutaneous and transdermal fentanyl. Furthermore, we evaluated rotations from the subcutaneous to the transdermal route.

Methods

Fifty-two patients treated with subcutaneous and/or transdermal fentanyl for moderate to severe cancer-related pain participated. A population pharmacokinetic model was developed and evaluated using non-linear mixed-effects modelling. For rotations from subcutaneous to transdermal fentanyl, a 1:1 dose conversion ratio was used while the subcutaneous infusion was continued for 12 h (with a 50 % tapering after 6 h). A 6-h scheme with 50 % tapering after 3 h was simulated using the final model.

Results

A one-compartment model with first-order elimination and separate first-order absorption processes for each route adequately described the data. The estimated apparent clearance of fentanyl was 49.6 L/h; the absorption rate constant for subcutaneous and transdermal fentanyl was 0.0358 and 0.0135 h⁻¹, respectively. Moderate to large inter-individual and inter-occasion variability was found. Around rotation from subcutaneous to transdermal fentanyl, measured and simulated plasma fentanyl concentrations rose and increasing side effects were observed.

Conclusions

We describe the pharmacokinetics of subcutaneous and transdermal fentanyl in one patient cohort and report several findings that are relevant for clinical practice. Further research is warranted to study the optimal scheme for rotations from the subcutaneous to the transdermal route.

Electronic supplementary material

The online version of this article (doi:10.1007/s00228-015-2005-x) contains supplementary material, which is available to authorized users.

Subcutaneous fluid and drug delivery: safe, efficient and inexpensive

Patients with difficult venous access or oral intolerance and clinical situations with inadequate response to oral therapy have generated the need for alternative routes of delivery for drugs and fluids.

The purpose of this study was to conduct a systematic review examining the evidence for subcutaneous (SC) administration of drugs and/or fluids.

We used a broad search strategy using electronic databases CINAHL, EMBASE, PubMed and Cochrane library, key terms and ‘Medical Subject Headings’ (MeSH) such as ‘subcutaneous route’, ‘hypodermoclysis’ and the name/group of the most used drugs via this route (e.g. ‘ketorolac, morphine, ceftriaxone’, ‘analgesics, opioids, antibiotics’).

We conclude that the SC route is an effective alternative for rehydration in patients with mild–moderate dehydration and offers a number of potential advantages in appropriately selected scenarios. Experience of administering drugs by this route suggests that it is well tolerated and is associated with minimal side-effects.

Alternative routes to oral opioid administration in palliative care: a review and clinical summary

OBJECTIVE

A major goal of palliative care is to provide comfort, and pain is one of the most common causes of treatable suffering in patients with advanced disease. Opioids are indispensable for pain management in palliative care and can usually be provided by the oral route, which is safe, effective, and of lowest cost in most cases. As patients near the end of life, however, the need for alternate routes of medication increases with up to 70% of patients requiring a nonoral route for opioid administration. In order to optimize patient care, it is imperative that clinicians understand existing available options of opioid administration and their respective advantages and disadvantages.

METHODS

We performed a literature review to describe the most commonly used and available routes that can substitute for oral opioid therapy and to provide a summary of factors affecting choice of opioid for use in palliative care in terms of benefits, indications, cautions, and general considerations.

RESULTS

Clinical circumstances will largely dictate appropriateness of the route selected. When the oral route is unavailable, subcutaneous, intravenous, and enteral routes are preferred in the palliative care population. The evidence supporting sublingual, buccal, rectal, and transdermal gel routes is mixed.

CONCLUSIONS

This review is not designed to be a critical appraisal of the quality of current evidence; rather, it is a summation of that evidence and of current clinical practices regarding alternate routes of opioid administration. In doing so, the overarching goal of this review is to support more informed clinical decision making.