Time-dependent efficacy of bacterial filters and infection risk in long-term epidural catheterization

Conjunctival sac microbiome in anophthalmic patients: Flora diversity and the impact of ocular prosthesis materials

Purpose

To explore the changes of bacterial flora in anophthalmic patients wearing ocular prosthesis (OP) and the microbiome diversity in conditions of different OP materials.

Methods

A cross-sectional clinical study was conducted, involving 19 OP patients and 23 healthy subjects. Samples were collected from the upper, lower palpebral, caruncle, and fornix conjunctiva. 16S rRNA sequencing was applied to identify the bacterial flora in the samples. The eye comfort of each OP patient was determined by a questionnaire. In addition, demographics information of each participant was also collected.

Results

The diversity and richness of ocular flora in OP patients were significantly higher than that in healthy subjects. The results of flora species analysis also indicated that in OP patients, pathogenic microorganisms such as Escherichia Shigella and Fusobacterium increased significantly, while the resident flora of Lactobacillus and Lactococcus decreased significantly. Within the self-comparison of OP patients, compared with Polymethyl Methacrylate (PMMA), prosthetic material of glass will lead to the increased colonization of opportunistic pathogens such as Alcaligenes, Dermabacter and Spirochaetes, while gender and age have no significant impact on ocular flora.

Conclusions

The ocular flora of OP patients was significantly different from that of healthy people. Abundant colonization of pathogenic microorganisms may have an important potential relationship with eye discomfort and eye diseases of OP patients. PMMA, as an artificial eye material, demonstrated potential advantages in reducing the colonization of opportunistic pathogens.

SBA 2020: Regional anesthesia safety recommendations update

The purpose of the Brazilian Society of Anesthesiology (SBA)’s Regional Anesthesia Safety Recommendations Update is to provide new guidelines based on the current relevant clinical aspects related to safety in regional anesthesia and analgesia. The goal of the present article is to provide a broad overview of the current knowledge regarding pre-procedure asepsis and antisepsis, risk factors, diagnosis and treatment of infectious complications resulting from anesthetic techniques. It also aims to shed light on the use of reprocessed materials in regional anesthesia practice to establish the effects of aseptic handling of vials and ampoules, and to show cost-effectiveness in the preparation of solutions to be administered continuously in regional blockades. Electronic databases were searched between January 2011 (final date of the literature search for the past SBA recommendations for safety in regional anesthesia) and September 2019. A total of 712 publications were found, 201 of which were included for further analysis, and 82 new publications were added into the review. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system was used to assess the quality of each study and to classify the strength of evidence. The present review was prepared by members of the SBA Technical Standards Committee.

[SBA 2020: Regional anesthesia safety recommendations update]

The purpose of the Brazilian Society of Anesthesiology's (SBA) Regional Anesthesia Safety Recommendations Update is to provide new guidelines based on the current relevant clinical aspects related to safety in regional anesthesia and analgesia. The goal of the present article is to provide a broad overview of the current knowledge regarding pre-procedure asepsis and antisepsis, risk factors, diagnosis and treatment of infectious complications resulting from anesthetic techniques. It also aims to shed light on the use of reprocessed materials in regional anesthesia practice to establish the effects of aseptic handling of vials and ampoules, and to show cost-effectiveness in the preparation of solutions to be administered continuously in regional blockades. Electronic databases were searched between January 2011 (final date of the literature search for the past SBA recommendations for safety in regional anesthesia) and September 2019. A total of 712 publications were found, 201 of which were included for further analysis, and 82 new publications were added into the review. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system was used to assess the quality of each study and to classify the strength of evidence. The present review was prepared by members of the SBA Technical Standards Committee.

Practice Advisory for the Prevention, Diagnosis, and Management of Infectious Complications Associated with Neuraxial Techniques

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[In vitro comparison of epidural bacteria filters permeability and screening scanning electron microscopy]

BACKGROUND AND OBJECTIVES

Epidural catheter bacteria filters are barriers in the patient-controlled analgesia/anaesthesia for preventing contamination at the epidural insertion site. The efficiency of these filters varies according to pore sizes and materials.

METHOD

The bacterial adhesion capability of the two filters was measured in vitro experiment. Adhesion capacities for standard Staphylococcus aureus (ATCC 25923) and Pseudomonas aeruginosa (ATCC 27853) strains of the two different filters (Portex and Rusch) which have the same pore size were examined. Bacterial suspension of 0.5 Mc Farland was placed in the patient-controlled analgesia pump, was filtered at a speed of 5mL/h. in continuous infusion for 48h and accumulated in bottle. The two filters were compared with colony counts of bacteria in the filters and bottles. At the same time, the filters and adhered bacteria were monitored by scanning electron microscope.

RESULTS

Electron microscopic examination of filters showed that the Portex filter had a granular and the Rusch filter fibrillary structure. Colony counting from the catheter and bottle showed that both of the filters have significant bacterial adhesion capability (p<0.001). After the bacteria suspension infusion, colony countings showed that the Portex filter was more efficient (p<0.001). There was not any difference between S. aureus and P. aeruginosa bacteria adhesion. In the SEM monitoring after the infusion, it was physically shown that the bacteria were adhered efficiently by both of the filters.

CONCLUSION

The granular structured filter was found statistically and significantly more successful than the fibrial. Although the pore sizes of the filters were same - of which structural differences shown by SEM were the same - it would not be right to attribute the changes in the efficiencies to only structural differences. Using microbiological and physical proofs with regard to efficiency at the same time has been another important aspect of this experiment.

Epidural Infusion of Morphine and Levobupivacaine through a Subcutaneous Port for Cancer Pain Management

BACKGROUND

To manage intractable cancer pain, an alternative to systemic analgesics is neuraxial analgesia. In long-term treatment, intrathecal administration could provide a more satisfactory pain relief with lower doses of analgesics and fewer side-effects than that of epidural administration. However, implantable drug delivery systems using intrathecal pumps in Korea are very expensive. Considering cost-effectiveness, we performed epidural analgesia as an alternative to intrathecal analgesia.

METHODS

We retrospectively investigated the efficacy, side effects, and complications of epidural morphine and local anesthetic administration through epidural catheters connected to a subcutaneous injection port in 29 Korean terminal cancer patients. Patient demographic data, the duration of epidural administration, preoperative numerical pain rating scales (NRS), side effects and complications related to the epidural catheterization and the drugs, and the numerical pain rating scales on the 1st, 3rd, 7th and 30th postoperative days were determined from the medical records.

RESULTS

The average score for the numerical pain rating scales for the 29 patients decreased from 7 ± 1.0 at baseline to 3.6 ± 1.4 on postoperative day 1 (P < 0.001). A similar decrease in pain intensity was maintained for 30 days (P < 0.001). Nausea and vomiting were the most frequently reported side effects of the epidural analgesia and two patients (6.9%) experienced paresthesia.

CONCLUSIONS

Epidural morphine and local anesthetic infusion with a subcutaneous pump seems to have an acceptable risk-benefit ratio and allows a high degree of autonomy to patients with cancer pain.

In vitro comparison of epidural bacteria filters permeability and screening scanning electron microscopy

BACKGROUND AND OBJECTIVES

Epidural catheter bacteria filters are barriers in the patient-controlled analgesia/anaesthesia for preventing contamination at the epidural insertion site. The efficiency of these filters varies according to pore sizes and materials.

METHOD

The bacterial adhesion capability of the two filters was measured in vitro experiment. Adhesion capacities for standard Staphylococcus aureus (ATCC 25923) and Pseudomonas aeruginosa (ATCC 27853) strains of the two different filters (Portex and Rusch) which have the same pore size were examined. Bacterial suspension of 0.5 Mc Farland was placed in the patient-controlled analgesia pump, was filtered at a speed of 5 mL/h. in continuous infusion for 48 h and accumulated in bottle. The two filters were compared with colony counts of bacteria in the filters and bottles. At the same time, the filters and adhered bacteria were monitored by scanning electron microscope.

RESULTS

Electron microscopic examination of filters showed that the Portex filter had a granular and the Rusch filter fibrillary structure. Colony counting from the catheter and bottle showed that both of the filters have significant bacterial adhesion capability (p<0.001). After the bacteria suspension infusion, colony countings showed that the Portex filter was more efficient (p<0.001). There was not any difference between S. aureus and P. aeruginosa bacteria adhesion. In the SEM monitoring after the infusion, it was physically shown that the bacteria were adhered efficiently by both of the filters.

CONCLUSION

The granular structured filter was found statistically and significantly more successful than the fibrial. Although the pore sizes of the filters were same - of which structural differences shown by SEM were the same - it would not be right to attribute the changes in the efficiencies to only structural differences. Using microbiological and physical proofs with regard to efficiency at the same time has been another important aspect of this experiment.

A review of epidural catheter-related infections

Spinal drug delivery is a generally safe and effective therapy for the treatment of both acute and chronic pain. However, it can be occasionally associated with significant complications, including neurologic injury, as a result of bleeding and infection in a confined space. This article focuses on risk factors for developing epidural catheter-related infections as well as strategies to minimize risks. Additionally, the diagnosis and management of epidural catheter-related infections, both superficial and deep, are discussed.

Infectious complications of regional anesthesia

PURPOSE OF REVIEW

Regional anesthesia is commonly used to provide intraoperative anesthesia and postoperative analgesia. Potential complications of both neuraxial and peripheral regional techniques include infectious sequelae. This review examines important components of practice that are known to minimize the risk of infection associated with regional anesthesia.

RECENT FINDINGS

Healthcare-associated infections increase morbidity and mortality, patient pain and suffering, direct medical costs, and hospital length-of-stay. Recently published national guidelines from subspecialty societies and government agencies emphasize the importance of strict aseptic technique in the prevention of infectious complications associated with regional anesthesia. Proper hand hygiene, the use of surgical masks, appropriate antiseptic selection and application, and proper preparation of local anesthetic infusate solutions are all considered essential components of asepsis. Anesthesia providers need to adhere to strict aseptic guidelines to minimize the risk of potentially devastating infectious complications.

SUMMARY

Infectious complications associated with regional anesthesia are exceedingly rare events. Adherence to strict aseptic guidelines as published by the American Society of Regional Anesthesia and Pain Medicine, American Society of Anesthesiologists, and the Royal College of Anaesthetists may reduce the risk of infectious complications.

Epidural local anesthetic plus corticosteroid for the treatment of cervical brachial radicular pain: single injection versus continuous infusion

BACKGROUND

Efficacy of epidural local anesthetics plus steroids for the treatment of cervicobrachial pain is uncertain.

METHODS

A prospective study randomized 160 patients with cervicobrachial pain resistant to conventional therapy. Patients were divided into 4 groups on the basis of the time between pain onset and treatment initiation: group A, 40 patients with pain onset 15 to 30 days; group B, 40 patients with pain from 31 to 60 days; group C, 40 patients, 61 to 180 days; and group D, 40 patients with pain >180 days. Patients of each group were randomized to receive an epidural block with bupivacaine and methylprednisolone at intervals of 4 to 5 days (Single injection) or continuous epidural bupivacaine every 6, 12, or 24 hours plus methylprednisolone every 4 to 5 days (Continuos epidural). The maximum duration of treatment (9 blocks in Single injection, and 30 days in Continuos epidural) was dependent on achieving Pain Control (PC) > or =80% [PC is defined by this formulae: (100) (VAS(initial)-VAS(final))/VAS(initial)]. Follow-up at 1 month and 6 months compared PC and the number of pain-free hours of sleep.

RESULTS

One hundred forty-one patients completed the study. The 4 groups had similar characteristics. At the 1-month and 6-month follow-up analysis based on the time between pain onset and treatment initiation showed that patients of group D, who received the Continuous epidural treatment, had significantly greater PC and significantly more pain-free hours of sleep compared with similar patients in Single injection.

CONCLUSIONS

Therapy with continuous epidural local anesthetic and methylprednisolone provides better control of chronic cervicobrachial pain compared with Single injection. These results are discussed with respect to the possible mechanism of action of the drugs and may relate to the physiopathologic mechanisms associated with neuronal plasticity that result in chronic pain.

Major complications of epidural analgesia after surgery: results of a six-year survey

We performed a retrospective case note review to identify the major complications of epidural analgesia occurring after surgery at our hospital. By cross-referencing the radiology, microbiology and patient information management system databases, we identified patients who had undergone either spinal magnetic resonance imaging or a lumbar puncture within 60 days of surgery in the period from January 2000 to December 2005. Review of these case notes identified six cases of epidural abscess, three of meningitis and three of epidural haematoma. Symptoms of epidural abscess or meningitis developed a median of 5 days after epidural catheter removal. Methicillin-resistant Staphylococcus aureus was the predominant pathogen. Epidural haematoma symptoms developed while the epidural catheter was in place. These symptoms were initially attributed to the epidural infusion. Diagnostic delays contributed to adverse neurological outcome in three patients. This study suggests that leg weakness is a critical monitor of spinal cord health. A national database is needed to establish a more accurate estimate of the incidence of major complications and to identify relevant risk factors.

Inflammation and infection complications of 2285 perineural catheters: a prospective study

BACKGROUND

Perineural catheters (PNCs) are increasingly being used. Few data are available on the infectious complications of PNCs. The incidence and localization of local inflammation and infection associated with PNCs were assessed.

METHODS

PNCs placed under sterile conditions for regional anesthesia and post-operative analgesia were evaluated prospectively. Local inflammation was defined as redness, swelling or pain on pressure at the catheter insertion site. Infection was defined as purulent material at the catheter insertion site with or without the need for surgical intervention.

RESULTS

In total, 2285 PNCs were evaluated: 600 axillary, 303 interscalene, 92 infraclavicular, 65 psoas compartment, 574 femoral, 296 sciatic and 355 popliteal. Local inflammation occurred in 4.2% and infection in 3.2%. The duration of PNC placement was a risk factor (P < 0.05). Surgical intervention was necessary in 0.9%. No late complications occurred in any patient. Interscalene catheters were associated with an increased risk of infection (4.3%; P < 0.05). Anterior proximal sciatic catheters were associated with a lower risk of local inflammation (1.7%; P < 0.05) and infection (0.4%; P < 0.05). Staphylococcus epidermidis and Staphylococcus aureus were isolated in 42% and 58% of catheter tip cultures, respectively.

CONCLUSION

In the present study population, infection of PNCs was a rare occurrence, but the incidence increased with the duration of PNC placement, and close clinical monitoring is required.

Risk factors for bacterial catheter colonization in regional anaesthesia

Background

Although several potential risk factors have been discussed, risk factors associated with bacterial colonization or even infection of catheters used for regional anaesthesia are not very well investigated.

Methods

In this prospective observational trial, 198 catheters at several anatomical sites where placed using a standardized technique. The site of insertion was then monitored daily for signs of infection (secretion at the insertion site, redness, swelling, or local pain). The catheters were removed when clinically indicated (no or moderate postoperative pain) or when signs of potential infection occurred. After sterile removal they were prospectively analyzed for colonization, defined as > 15 colony forming units.

Results

33 (16.7%) of all catheters were colonized, and 18 (9.1%) of these with additional signs of local inflammation. Two of these patients required antibiotic treatment due to superficial infections. Stepwise logistic regression analysis was used to identify factors associated with catheter colonization. Out of 26 potential factors, three came out as statistically significant. Catheter placement in the groin (odds-ratio and 95%-confidence interval: 3.4; 1.5–7.8), and repeated changing of the catheter dressing (odds-ratio: 2.1; 1.4–3.3 per removal) increased the risk for colonization, whereas systemic antibiotics administered postoperatively decreased it (odds ratio: 0.41; 0.12–1.0).

Conclusion

Colonization of peripheral and epidural nerve catheter can only in part be predicted at the time of catheter insertion since two out of three relevant variables that significantly influence the risk can only be recorded postoperatively. Catheter localisation in the groin, removal of the dressing and omission of postoperative antibiotics were associated with, but were not necessarily causal for bacterial colonization. These factors might help to identify patients who are at increased risk for catheter colonization.

Subcutaneous tunneling of caudal catheters reduces the rate of bacterial colonization to that of lumbar epidural catheters

Bacterial colonization is regarded as a causative factor for septic complications of caudal catheters in children. To determine whether tunneling caudal catheters reduces the bacterial colonization rate effectively, we evaluated 506 children being treated with tunneled or untunneled caudal or untunneled lumbar epidural catheters. Four-hundred-nine children completed the study. After aseptic removal, the catheters were cultured and sent for microbiological assessment. We found a bacterial colonization rate of 29% in untunneled caudal catheters, 11% in tunneled caudal catheters, and 9% in untunneled lumbar catheters. No severe infectious complications were reported. There was no correlation between catheter retention time and bacterial colonization except for the first 24 h, during which no bacterial colonization was detected. The overall colonization rate remained constant at approximately 13%. We found a positive correlation between bacterial colonization and redness at the catheter entry site. We conclude that tunneled caudal epidural catheters can be used in children for postoperative analgesia without an increased risk of epidural infection.

Filters in anaesthesia and intensive care

The use of various types of filters in anaesthesia and intensive care seems ubiquitous, yet authentication of the practice is scarce and controversies abound. This review examines evidence for the practice of using filters with blood and blood product transfusion (standard blood filter, microfilter, leucocyte depletion filter), infusion of fluids, breathing systems, epidural catheters, and at less common sites such as with Entonox inhalation in non-intubated patients, forced air convection warmers, and air-conditioning systems. For most filters, the literature failed to support routine usage, despite this seemingly being popular and innocuous. The controversies, as well as guidelines if available, for each type of filter, are discussed. The review aims to rationalize the place of various filters in the anaesthesia and intensive care environment.

Intrathecal catheters: developing consistency in filter use and dressings in Perth, Australia

The use of opioids presents practitioners with many challenges, such as the variation in responses and side effects seen with traditional methods of administration. This has prompted an increase in the consideration of the intrathecal route for the management of patients with refractory cancer pain. Although this has increased the therapeutic options available to patients, it has also led to more complicated pain management strategies. In Perth, Western Australia, it was identified that clinical variations, especially in the programming of the pump maintenance of the filters and associated dressings, occurred between service providers, causing confusion and anxiety for patients, families and practitioners. This article discusses a review of nursing management of patients receiving intrathecal analgesia and the collaboration of all services in the development of evidence-based policy.

Survey of epidural analgesia management in general intensive care units in England

BACKGROUND

The management of epidural analgesia is controversial. Many intensive care unit (ICU) patients may benefit from this form of analgesia but have one or more contraindications to its use. Sepsis, coagulopathy, insertion in a sedated, ventilated patient, and lack of consent are common problems in ICU patients. Little has been published to help guide practice in this area. I wished to establish the current practice of the management of epidural analgesia in general ICUs in England when relative or absolute contraindications occur, in order to determine the current standard of care for placement and use of epidural analgesia in ICU patients.

METHODS

A postal questionnaire survey of the management of epidural analgesia in critically ill patients was sent to the named clinical director of all (216) general ICUs in England.

RESULTS

Responses were received from 159 (75%) units: 89% of responding units use epidural analgesia but only 51(32%) have a written policy covering its use. Anesthetists or intensivists with an anesthetic background sited all epidural catheters; 68% of units would not site an epidural in a patient with positive blood cultures; but only 52% considered culture negative sepsis (systemic signs of sepsis with no organism isolated) to be a contraindication. Neither lack of consent nor the need for anticoagulation after the catheter had been sited were considered contraindications to inserting an epidural catheter by the majority of respondents. Although 71% of the units would remove an epidural catheter if a patient developed positive blood cultures after it had been sited, the majority of the ICUs did not consider culture negative sepsis and the need for anticoagulation contraindications to maintain a previously sited epidural.

CONCLUSIONS

Practice varied considerably with little consensus. Although all the respondents use epidural analgesia in critically ill patients, the indications and contraindications to epidural analgesia remain controversial, and further research is required to help define the role of epidural analgesia in this high-risk group.

[Evaluation of antibacterial filters for peridural obstetrical anesthesia]

OBJECTIVES

To assess the antibacterial efficiency of filters used in obstetrics when epidural top-ups are performed.

STUDY DESIGN

Observational prospective study.

PATIENTS AND METHODS

We aseptically collected 201 antibacterial filters that had been used for top-ups with ropivacaine +/- sufentanil for epidural analgesia during labour. We flushed them first with 2 mL of saline and then with 2 mL of a solution containing 1.5 x 10(6) Staphylococcus epidermidis/mL. The filtrates were incubated at 37 degrees C for 72 h. Number of top-ups and duration of epidural analgesia are expressed as median (extremes).

RESULTS

3 (1-10) top-ups were performed for labour analgesia over a period of 6.5 h (1.8-18). After filtering, all the solutions were found to be sterile. Especially, when using Staphylococcus epidermidis solutions, bacteria were not found beyond any filter. These results suggest the integrity of the filter membrane after several boluses. No infection related to epidural analgesia was reported.

CONCLUSION

Antibacterial filters provide a good protection against a potentially contaminated procedure during epidural top-ups.

Pain and symptom control in terminally ill children

The management of pain in terminally ill pediatric patients has incalculable benefits to patients, their families, and physicians and nurses. A therapeutic management plan is dependent on a thorough understanding of the causes of pain in these patients, on pain assessment, and on the myriad drugs and drug strategies that are essential in pain treatment. Aggressive symptom control of treatment-related side effects can ensure successful implementation of such a plan.

[Risk of infection and locoregional anesthesia]

We analysed the data on the risk of infection during practice of locoregional anaesthesia (LRA) and propose recommendations for its prevention. The epidemiologic data show that the incidence is very low. The risk of LBA during sepsis is uncertain and the data are often contradictory. The benefit-risk ratio must be considered, specifically in obstetrics. Precautions which must be followed during the practice of LRA are discussed.

A survey of the practice of thoracic epidural analgesia in the United Kingdom

A postal survey of the practice of thoracic epidural analgesia was sent to 275 hospitals in the United Kingdom. Responses were received from 70% of hospitals. Informed consent is rarely adequately obtained, with only 28% of respondents mentioning even the most common complications. Epidural cannulation is most often (60%) performed following induction of general anaesthesia, rather than in the awake patient. A test dose of local anaesthetic without adrenaline is usual. Neither aspirin nor low-dose heparin are considered a contraindication. The majority of respondents used a combination of bupivacaine with fentanyl (51%) or diamorphine (40%), usually administered by continuous infusion. Drugs were frequently prepared and adjusted by anaesthetic staff. The majority of epidurals (63%) are nursed in intensive care units postoperatively. Properly funded pain management teams, at present unusual, would facilitate ward-based epidural management and release intensive care resource. A central register of epidural complications is required to provide valuable evidence for the optimum practice of thoracic epidural analgesia.

[Evaluation of aseptic measures in the performance of epidural catheterization and perception of its risk of infection. Results of a survey in Languedoc-Roussillon]

OBJECTIVE

To assess the level of aseptic practice in epidural catheterization, to determine the perception of its infectious risk and the knowledge of epidural abscess symptoms.

STUDY DESIGN

Cross-sectional regionwide retrospective survey.

MATERIAL

Questionnaire sent after telephone call to 160 anaesthesiologists performing epidural anaesthesia in Languedoc-Roussillon.

RESULTS

Replies were obtained from 96 anaesthesiologists working in 26 centres. Handwashing techniques were various: 53% onefolded with an antiseptic preparation, 38% twofolded and 9% used a simple soap; 41% did never wear a long-sleeved sterile surgical gown and only 53% wored simultaneously a cap; a surgical mask and a sterile gown; 4% of the Tuohy needles were reusable; 21% of the dressings permitted continuous inspection of the site of puncture; 12.5% admitted not to know epidural abcess symptoms and 30% ignored the most adapted radiological diagnostic means.

CONCLUSIONS

Good aseptic practice in epidural catheterization should be clarified by a consensus conference. There is an obvious lack of knowledge concerning features of epidural abscess.