[Efficacy of a continuous infusion of local anesthetic into the surgical wound for pain relief after abdominal hysterectomy]

Sustained release local anesthetics for pain management: relevance and formulation approaches

This review attempted to ascertain the rationale for the formulation of sustained-release local anesthetics and summarize the various formulation approaches designed to date to achieve sustained and localized local analgesic effects. The incidence of pain, which is the concern of patients as well as health care professionals, is increasing due to accidents, surgical procedures, and other diseases. Local anesthetics can be used for the management of moderate to severe acute and chronic pain. They also allow regional analgesia, in situations where the cause and source of the pain are limited to a particular site or region, without the need for loss of consciousness or systemic administration of other analgesics thereby decreasing the risk of potential toxicities. Though they have an interesting antipain efficacy, the short duration of action of local anesthetics makes the need for their multiple injections or opioid adjuvants mandatory. To overcome this problem, different formulations are being designed that help achieve prolonged analgesia with a single dose of administration. Combination with adjuvants, liposomal formulations, lipid-based nanoparticles, thermo-responsive nanogels, microspheres, microcapsules, complexation with multivalent counterions and HP-β-CD, lipid-based nanoparticles, and bio-adhesive films, and polymeric matrices are among the approaches. Further safety studies are required to ensure the safe and effective utilization of sustained-release local anesthetics. Moreover, the release kinetics of the various formulations should be adequately established.

[Safety of a multiperforated catheter implanted in the surgical wound for the continuous infusion of local anaesthetics in post-operative analgesia]

OBJECTIVE

To evaluate the incidence of infection at the surgical site in patients who have a multiperforated catheter implant for continuous infusion of a local anaesthetic as a local analgesic.

PATIENTS AND METHOD

An observational, descriptive and prospective study, of one month duration. It included 50 patients subjected to selective laparotomy in whom a multiperforated pre-peritoneal catheter was implanted for analgesia purposes (Painfusor®. Baxter). Patients with a surgical incision of less than 15 cm and/or ASA>III, were excluded from the study.

RESULTS

The catheter was removed from all patients at 48 hours. An infection at the surgical site was present in 6% of the patients who had the catheter implanted, which was similar to the incidence in clean-contaminated surgery (5.5%; 95% CI: 3.4-8.7%). Colonisation of the catheter was observed in two patients, causing only one infection of the surgical site.

CONCLUSIONS

The use of an in-situ pre-peritoneal catheter for post-surgical anaesthesia does not increase the risk of surgical site infection.

[Safety of a multiperforated catheter implanted in the surgical wound for the continuous infusion of local anaesthetics in post-operative analgesia]

OBJECTIVE

To evaluate the incidence of infection at the surgical site in patients who have a multiperforated catheter implant for continuous infusion of a local anaesthetic as a local analgesic.

PATIENTS AND METHOD

An observational, descriptive and prospective study, of one month duration. It included 50 patients subjected to selective laparotomy in whom a multiperforated pre-peritoneal catheter was implanted for analgesia purposes (Painfusor®. Baxter). Patients with a surgical incision of less than 15 cm and/or ASA>III, were excluded from the study.

RESULTS

The catheter was removed from all patients at 48 hours. An infection at the surgical site was present in 6% of the patients who had the catheter implanted, which was similar to the incidence in clean-contaminated surgery (5.5%; 95% CI: 3.4-8.7%). Colonisation of the catheter was observed in two patients, causing only one infection of the surgical site.

CONCLUSIONS

The use of an in-situ pre-peritoneal catheter for post-surgical anaesthesia does not increase the risk of surgical site infection.

Local infiltration analgesia

Pain after major abdominal, orthopedic, and thoracic surgeries can be significant causing unacceptable morbidity. Poorly controlled pain results in patient dissatisfaction and may also be associated with major morbidities, including perioperative myocardial ischemia, pulmonary complications, altered immune function, and postoperative cognitive dysfunction. Various techniques are currently used to manage this pain, and opioids are amongst the most frequently used. Recent literature supports the use of regional anesthesia in the form of various peripheral nerve blocks as a better alternative. This article discusses the role and evidence for wound infiltration analgesia in general surgery, orthopedic surgery, neurosurgery, and thoracic surgery.