A History of Intraspinal Analgesia, a Small and Personal Journey

Observation of Anesthetic Effect of Dexmedetomidine Combined With Intraspinal Anesthesia in Hip Arthroplasty and its Effect on Postoperative Delirium and Stress Response

Objective

To observe the anesthetic effect of dexmedetomidine combined with spinal anesthesia in hip arthroplasty, and to analyze the effects of dexmedetomidine on postoperative stress response, incidence of delirium, immune function and inflammatory indicators.

Methods

A total of 42 patients who underwent hip replacement in our hospital from March 2020 to June 2021 were selected as the research subjects and randomly divided into the control group and the observation group, 21 cases in each group. The control group was given intraspinal anesthesia, and the observation group was given dexmedetomidine on this basis. The onset time and maintenance time of sensory and motor nerve block were recorded. Stress response indexes [cortisol (Cor), blood glucose (Glu), adrenaline (E), noadrenaline (NE)], T lymphocyte subsets (CD3+, CD4+, CD8+, CD4+/CD8+), inflammatory indexes [tumor necrosis factor -α (TNF-α) and interleukin-6 (IL-6)] were detected before and after operation, and the incidence of postoperative delirium in both groups was recorded.

Results

The onset time of sensory nerve block and motor block in the observation group were lower than those in the control group, and the retention time of sensory nerve block and motor nerve block were higher than those in the control group (P < 0.05). After surgery, the levels of Cor, Glu, E and NE in the observation group were lower than those in the control group (P < 0.05). After surgery, the incidence of postoperative delirium in the observation group (4.79%) was lower than that in the control group (28.57%) (P < 0.05). After surgery, the levels of CD3+, CD4+, CD8+, and CD4+/CD8+ in the observation group were higher than those in the control group (P < 0.05). After surgery, the levels of TNF-α and IL-6 in the observation group were lower than those in the control group (P < 0.05).

Conclusion

The combined use of dexmedetomidine and intraspinal anesthesia has good anesthesia effect in hip joint replacement, which can greatly reduce the stress response of patients, reduce the incidence of postoperative delirium, and effectively restore the immune function of patients, reduce the level of inflammatory response, and has high clinical application value.

Targeted Drug Delivery for Chronic Nonmalignant Pain: Longitudinal Data From the Product Surveillance Registry

OBJECTIVES

To assist in assessment of therapy risks and benefits of targeted drug delivery (TDD) for chronic nonmalignant pain using registry data on product performance, adverse events, and elective device replacement.

MATERIALS AND METHODS

The Product Surveillance Registry (PSR) (NCT01524276) is an ongoing prospective, long-term, multicenter registry enrolling consented patients implanted with an intrathecal drug delivery system. Patients are followed prospectively with participating investigators providing pump and catheter performance data for events related to the device, procedure, and therapy. Event descriptions include patient symptoms and outcomes.

RESULTS

Registry data from the 4646 patients (59.7% female) treated with TDD for chronic, nonmalignant pain at 59 registry sites between August 2003 and October 2019, with over 17,000 patient-years (4646 patients with 44 months average follow-up), were analyzed. Registry discontinuation was largely (46.2% of discontinued patients) due to study site closure and patient death; exit due to an adverse or device event was limited to 10.2%.

CONCLUSIONS

Treating chronic pain with escalating doses of strong systemic opioids often leads to inconsistent pain control, impaired function, untenable side effects, and reduced quality of life and this practice has contributed to the current opioid crisis in the United States. TDD has been an available therapy for these patients for greater than 30 years, and data from this real-world registry offer supporting evidence to the long-term safety of this therapy as an alternative to systemic opioids, as well as insights into patient acceptance and satisfaction.

CE: Intrathecal Pumps for Managing Cancer Pain

: It is estimated that more than 1.6 million new cases of cancer were diagnosed in the United States in 2014. Among patients with cancer, moderate to severe pain is prevalent and can be refractory, even with the use of systemic opioids, which may cause adverse effects that are difficult to manage at the doses required to control pain. When delivered intrathecally, however, opioids and adjuvant analgesics may provide greater pain relief at dramatically lower doses and with fewer adverse effects. Although the use of intrathecal drug delivery systems for cancer pain management has increased dramatically over the past several years and is expected to continue growing, patients with intrathecal pumps often report interactions with nurses unfamiliar with the technology. This article provides an overview of intrathecal pump therapy and explains how it prolongs duration of action and improves the efficacy of certain analgesics while reducing their adverse effects. The author discusses the costs involved, the patients most likely to derive benefit, the types of pumps currently used in the United States, the medications that can be delivered intrathecally, the potential risks and complications associated with intrathecal therapy, and the nursing care required by patients who use an intrathecal pump.

Spinal opioid bioavailability in postoperative pain

Opioids have been used for spinal analgesia for more than a century, and their injection epidurally and intrathecally has a key role in the control of postoperative pain. Since the discovery of the endogenous opioid system, 3 decades ago, their use has become more generalized in obstetric analgesia, the management of chronic pain, and acute postoperative pain. To use opioids effectively for this type of analgesia, it is important to understand the pharmacokinetics and clinical pharmacology of these drugs, specifically those that produce analgesia by an intrinsic spinal mechanism. Evidence from animal and human experiments indicates that hydrophilic opioids (such as hydromorphone and morphine) bind more strongly to specific receptors within the dorsal horn of the spinal cord than lipophilic opioids (such as alfentanil, fentanyl, and sufentanil). This can be understood by considering the spinal cord selectivity and bioavailability of these opioids. This difference is attributable to differences in the pharmacokinetic and pharmacodynamic properties of the 2 groups. It is more difficult for lipophilic opioids to reach and remain at sufficiently high concentrations at the site of action due to their sequestration in epidural fat and rapid plasma clearance from both epidural and intrathecal spaces, resulting in analgesia with a limited spread and duration, as well as the appearance of early supraspinal side effects. In contrast, morphine has very different properties, including greater spinal bioavailability and therefore administered neuraxially, it is suitable choice for the treatment of acute postoperative pain. However, when using morphine, a greater incidence of adverse effects can be expected, and it requires careful patient selection.