Infectious complications of regional anesthesia

SOMANZ position statement for the investigation and management of sepsis in pregnancy 2023

BACKGROUND

The Society of Australia and New Zealand (SOMANZ) published its first sepsis in pregnancy and the postpartum period guideline in 2017 (Aust N Z J Obstet Gynaecol, 57, 2017, 540). In the intervening 6 years, maternal mortality from sepsis has remained static.

AIMS

To update clinical practice with a review of the subsequent literature. In particular, to review the definition and screening tools for the diagnosis of sepsis.

MATERIALS AND METHODS

A multi-disciplinary group of clinicians with experience in all aspects of the care of pregnant women analysed the clinical evidence according to the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system following searches of Cochrane, Medline and EMBASE. Where there were conflicting views, the authors reviewed the topic and came to a consensus. All authors reviewed the final position statement.

RESULTS

This position statement has abandoned the use of the quick Sequential Organ Failure Assessment score (qSOFA) score to diagnose sepsis due to its poor performance in clinical practice. Whilst New Zealand has a national maternity observation chart, in Australia maternity early warning system charts and vital sign cut-offs differ between states. Rapid recognition, early antimicrobials and involvement of senior staff remain essential factors to improving outcomes.

CONCLUSION

Ongoing research is required to discover and validate tools to recognize and diagnose sepsis in pregnancy. Australia should follow New Zealand and have a single national maternity early warning system observation chart.

Epidural Blood Patch in a Patient with a Hematological Malignancy

Postdural puncture headache is a frequently encountered complication following procedures such as lumbar puncture, neuraxial anesthesia, or intrathecal drug delivery device implantation. It classically presents as a painful orthostatic headache that is exacerbated when a patient is upright. For treatment, patients are often started on conservative options such as hydration, caffeine, bedrest, and NSAID analgesics; however, certain patients who fail these therapies may require intervention with an epidural blood patch. The epidural blood patch remains the gold standard for treating refractory postdural puncture headache. Contraindications to epidural blood patch include severe coagulopathy, patient refusal, or infection at the intended site of entry. There are no clear consensus recommendations regarding patients with a hematological malignancy and potential risk that autologous blood may seed malignant cells into the neuraxis. In this case report, we present a patient with acute myeloid leukemia who developed a postdural puncture headache after receiving subarachnoid administration of antineoplastics. The patient was refractory to conservative therapy, prompting multidisciplinary consultation and discussion with the patient about the risks and benefits of proceeding with an epidural blood patch. Ultimately, the patient elected to proceed with the offered epidural blood patch which led to complete resolution of his painful headaches and did not cause any spread of malignant cells into his neuraxis or cerebral spinal fluid.

The diagnostic value of serum Borrelia burgdorferi antibodies and seroconversion after Lyme neuroborreliosis, a nationwide observational study

OBJECTIVES

Clinical guidelines disagree on the diagnostic usefulness of Borrelia burgdorferi (Bb) serum antibodies (serum-Bb) in investigation of Lyme neuroborreliosis (LNB). We investigated the association between serum-Bb and Bb intrathecal antibody index (Bb-AI) and rates of seroconversion and seroreversion after LNB.

METHODS

Danish residents who had a Bb-AI and corresponding serum-Bb measured between 1994-2020 were identified at all Danish departments of clinical microbiology. We used descriptive statistics to examine the proportions of positive Bb-AI combined with positive or negative serum-Bb antibody tests. Next, the rate of seroconversion and seroreversion among those with positive Bb-AI and either an initial negative or positive serum-Bb was estimated.

RESULTS

We included 34 609 individuals with a Bb-AI and corresponding serum-Bb. The proportion of individuals with positive Bb-AI who had negative serum-Bb was 16.8% (95% confidence interval (CI), 15.1-18.6). The proportion of individuals with positive serum-Bb IgM, serum-Bb IgG or serum-Bb IgM and IgG antibodies who had positive Bb-AI was 10.6% (95% CI, 9.5-11.8), 24.7% (95% CI, 23.0-26.4) and 45.0% (95% CI, 42.4-48.0), respectively. The proportion of children (<18 years) with positive serum-Bb IgM and IgG antibodies who had a positive Bb-AI was 59.7% (95% CI, 53.4-65.8). The proportion of individuals with positive Bb-AI with initial negative or positive serum-Bb antibodies who seroconverted or seroreverted within 2 years was 17.3% (95% CI, 6.9-27.8) and 23.2% (95% CI, 19.1-27.7), respectively.

CONCLUSIONS

Serum-Bb antibodies could not predict results of Bb-AI. A fifth of both seronegative and seropositive individuals with positive Bb-AI seroconverted or seroreverted within 2 years.

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.

SOMANZ guidelines for the investigation and management sepsis in pregnancy

SOMANZ (Society of Obstetric Medicine Australia and New Zealand) has written a guideline to provide evidence-based guidance for the investigation and care of women with sepsis in pregnancy or the postpartum period. The guideline is evidence-based and incorporates recent changes in the definition of sepsis. The etiology, investigation and treatment of bacterial, viral and non-infective causes of sepsis are discussed. Obstetric considerations relevant to anaesthetic and intensive care treatment in sepsis are also addressed. A multi-disciplinary group of clinicians with experience in all aspects of the care of pregnant women have contributed to the development of the guidelines. This is an executive summary of the guidelines.

Clinical and microbiological evaluation of epidural and regional anaesthesia catheters in injured UK military personnel

INTRODUCTION

The adoption of regional and epidural analgesia in UK military personnel injured in action during Op HERRICK increased from 2008, in line with structural and environmental developments in the UK medical treatment facility. Historically, there have been concerns that invasive analgesic techniques could carry an increased risk of infection, due to the mechanism of injury and the environmental conditions in which the injuries were sustained. Consequently, the epidural and continuous peripheral nerve blockade (CPNB) catheters that were inserted in UK military personnel during a 33-month period of Op HERRICK were clinically and microbiologically examined, after subsequent admission to the University Hospitals Birmingham (UHB) NHS Trust.

METHODS

Data on epidural and CPNB insertions were collected via the specialist pain service at UHB over the study period, including de novo and replacement insertions performed in both Afghanistan and the UK. Patients were regularly reviewed and relevant clinical concerns were documented in patients' case notes as necessary. The anatomical site, duration of placement and the results of microbiological culture of the epidural and CPNB catheter tips were all recorded.

RESULTS

Overall, 236 catheters were assessed, of which 151 catheter tips (64%) were cultured (85 epidural, 66 CPNB). Of these, 48 grew bacteria (34% of cultured epidurals and 29% of cultured CPNB). There was no difference between the colonisation rates of epidurals inserted in Afghanistan and the UK. Only one infection related to a misplaced epidural catheter was confirmed.

CONCLUSIONS

With the exception of the epidural (34%) and proximal sciatic (42%) catheters, these figures, in a military cohort characterised by significant injury scores, are consistent with those reported for civilian surgical patients. The results strongly support the expansion of regional analgesia during Op HERRICK from 2008 onwards. The outcomes suggest a possible translation into civilian major trauma practice.

A Review of Current Analgesic Techniques in Cardiac Surgery. Is Epidural Worth it?

In this review we addressed the various analgesic techniques in cardiac surgery, especially regional methods such as thoracic epidural anesthesia (TEA). There are many techniques available for management of postoperative pain after cardiac operation including intravenous administration of analgesic drugs, infiltration of local anesthetics, nerve blocks, and neuroaxial techniques. Although there are many evidences declaring the benefits of neuroaxial blockade in improving postoperative well-being and quality of care in these patients, some studies have revealed limited effect of TEA on overall morbidity and mortality after cardiac surgery. On the other hand, some investigators have raised the concern about epidural hematoma in altered coagulation and risks of infection and local anesthetics toxicity during and after cardiac procedures. In present review, we tried to discuss the most recent arguments in the field of this controversial issue. The final conclusion about either using regional anesthesia in cardiac surgery or not has been assigned to the readers.

WITHDRAWN: Epidural blood patching for preventing and treating post-dural puncture headache

This review is out of date, and the original authors are no longer available to update it.

The editorial group responsible for this previously published document have withdrawn it from publication.

A prospective randomised trial to compare the efficacy of povidone-iodine 10% and chlorhexidine 2% for skin disinfection

Context:

Infectious complications of invasive procedures affect patient outcomes adversely. Choice of antiseptic solution at the time of insertion is one of the major factors affecting their incidence.

Aims:

This study was undertaken to compare efficacy of chlorhexidine 2% and povidone iodine 10% for skin disinfection prior to placement of epidural and central venous catheters (CVCs).

Settings and Design:

A prospective randomised trial in the operating rooms of a tertiary referral cancer centre.

Methods:

Sixty consecutive adult patients undergoing elective oncosurgery requiring placement of epidural and CVCs were enrolled. Paired skin swabs were collected before and after application of the antiseptic solution. The samples were incubated in McConkey's media and blood agar at 35°C for up to 24 h. Any bacterial growth was graded as: <10 colonies - poor growth, 10-50 colonies - moderate growth and >50 colonies as heavy growth. Data on demographics and antibiotic prophylaxis and costs was collected for all patients.

Statistical Analysis:

Student's t-test and Mann-Whitney tests were used to analyse data, P<0.05 was considered significant.

Results:

Demographics and antibiotic prophylaxis use was similar in both groups. Before application of antiseptic solution, a variety of micro-organisms were grown from most patients with growth ranging from none-heavy. No organism was grown after application of either antiseptic solution from any patient.

Conclusions:

We found no differences between 2% chlorhexidine and 10% povidone-iodine for skin disinfection in regard to costs, efficacy or side-effects.

Protective mechanical ventilation during general anesthesia for open abdominal surgery improves postoperative pulmonary function

BACKGROUND

The impact of intraoperative ventilation on postoperative pulmonary complications is not defined. The authors aimed at determining the effectiveness of protective mechanical ventilation during open abdominal surgery on a modified Clinical Pulmonary Infection Score as primary outcome and postoperative pulmonary function.

METHODS

Prospective randomized, open-label, clinical trial performed in 56 patients scheduled to undergo elective open abdominal surgery lasting more than 2 h. Patients were assigned by envelopes to mechanical ventilation with tidal volume of 9 ml/kg ideal body weight and zero-positive end-expiratory pressure (standard ventilation strategy) or tidal volumes of 7 ml/kg ideal body weight, 10 cm H2O positive end-expiratory pressure, and recruitment maneuvers (protective ventilation strategy). Modified Clinical Pulmonary Infection Score, gas exchange, and pulmonary functional tests were measured preoperatively, as well as at days 1, 3, and 5 after surgery.

RESULTS

Patients ventilated protectively showed better pulmonary functional tests up to day 5, fewer alterations on chest x-ray up to day 3 and higher arterial oxygenation in air at days 1, 3, and 5 (mmHg; mean ± SD): 77.1 ± 13.0 versus 64.9 ± 11.3 (P = 0.0006), 80.5 ± 10.1 versus 69.7 ± 9.3 (P = 0.0002), and 82.1 ± 10.7 versus 78.5 ± 21.7 (P = 0.44) respectively. The modified Clinical Pulmonary Infection Score was lower in the protective ventilation strategy at days 1 and 3. The percentage of patients in hospital at day 28 after surgery was not different between groups (7 vs. 15% respectively, P = 0.42).

CONCLUSION

A protective ventilation strategy during abdominal surgery lasting more than 2 h improved respiratory function and reduced the modified Clinical Pulmonary Infection Score without affecting length of hospital stay.

Necrotizing fasciitis after spinal anesthesia

Regional anesthesia is the preferred technique for Cesarean delivery. Strict aseptic precautions should be taken; otherwise, infectious complications including abscess formation, meningitis and necrotizing fasciitis may result. We report a case of a 26-year-old post-partum female who presented with necrosis of the skin of back following spinal anesthesia, which was administered for Cesarean delivery 5 days prior at a private nursing home. On presentation, she was drowsy, appeared dehydrated and febrile. Examination of her back revealed necrosis of skin extending from just below the scapula to the gluteal region. Debridement of skin over the back was performed, and intravenous antibiotics started. After three debridements following which skin grafting was performed, she made complete recovery. Infectious complications following regional anesthesia are rare, and most of the literature focuses on colonization of epidural catheters or epidural abscess. There is no report of necrotizing fasciitis following spinal anesthesia so far. Sources of infection that are suspected in our case include: local anesthetic solution used for subcutaneous infiltration, nonadherence to aseptic precautions, skin flora of patient, endogenous source and nasopharyngeal flora of anesthesiologist. We considered each possibility, and the most likely cause in our case appears to be infection from an already-used vial of a local anesthetic agent. Local anesthetics have bacteriostatic properties, but infection may still be transmitted through contaminated solutions. The present case highlights the importance of maintaining strict aseptic precautions, avoiding reusing multidose vials and early recognition of this complication as timely intervention can be lifesaving.

Risks and benefits of thoracic epidural anaesthesia

Thoracic epidural anaesthesia (TEA) reduces cardiac and splanchnic sympathetic activity and thereby influences perioperative function of vital organ systems. A recent meta-analysis suggested that TEA decreased postoperative cardiac morbidity and mortality. TEA appears to ameliorate gut injury in major surgery as long as the systemic haemodynamic effects of TEA are adequately controlled. The functional benefit in fast-track and laparoscopic surgery needs to be clarified. Better pain control with TEA is established in a wide range of surgical procedures. In a setting of advanced surgical techniques, fast-track regimens and a low overall event rate, the number needed to treat to prevent one death by TEA is high. The risk of harm by TEA is even lower, and other methods used to control perioperative pain and stress response also carry specific risks. To optimize the risk-benefit balance of TEA, safe time intervals regarding the use of concomitant anticoagulants and consideration of reduced renal function impairing their elimination must be observed. Infection is a rare complication and is associated with better prognosis. Close monitoring and a predefined algorithm for the diagnosis and treatment of spinal compression or infection are crucial to ensure patient safety with TEA. The risk-benefit balance of analgesia by TEA is favourable and should foster clinical use.

End-to-end military pain management

The last three years have seen significant changes in the Defence Medical Services approach to trauma pain management. This article seeks to outline these changes that have occurred at every level of the casualty's journey along the chain of evacuation, from the point of injury to rehabilitation and either continued employment in the Services or to medical discharge. Particular attention is paid to the evidence for the interventions used for both acute pain and chronic pain management. Also highlighted are possible differences in pain management techniques between civilian and military casualties.

Epidural blood patching for preventing and treating post-dural puncture headache

BACKGROUND

This is an update of a Cochrane Review first published in Issue 2, 2002. Dural puncture is a common procedure, but leakage of cerebrospinal fluid (CSF) from the resulting dural defect may cause post-dural puncture headache (PDPH) after the procedure, and this can be disabling. Injecting an epidural blood patch around the site of the defect may stop this leakage.

OBJECTIVES

To assess the possible benefits and harms of epidural blood patching in both prevention and treatment of PDPH.

SEARCH STRATEGY

We searched the Cochrane PaPaS Group Trials Register; CENTRAL; MEDLINE and EMBASE in April 2009.

SELECTION CRITERIA

We sought all randomised controlled trials (RCTs) that compared epidural blood patch versus no epidural blood patch in the prevention or treatment of PDPH among all types of participants undergoing dural puncture for any reason. The primary outcome of effectiveness was postural headache.

DATA COLLECTION AND ANALYSIS

One review author extracted details of trial methodology and outcome data from studies considered eligible for inclusion. We invited authors of all such studies to provide any details that were unavailable in the published reports. We performed intention-to-treat (ITT) analyses using the Peto O-E method. We also extracted information about adverse effects (post-dural puncture backache and epidural infection).

MAIN RESULTS

Nine studies (379 participants) were eligible for inclusion. Prophylactic epidural blood patch improved PDPH compared to no treatment (OR 0.11, 95% CI 0.02 to 0.64, one study), conservative treatment (OR 0.06, 95% CI 0.03 to 0.14, two studies) and epidural saline patch (OR 0.16, 95% CI 0.04 to 0.55, one study). However, prophylactic epidural blood patch did not result in less PDPH than a sham procedure (one study). Therapeutic epidural blood patch resulted in less PDPH than conservative treatment (OR 0.18, 95% CI 0.04 to 0.76, one study) and a sham procedure (OR 0.04, 95% CI 0.00 to 0.39, one study). Backache was more common with epidural blood patch. However, these studies had very small numbers of participants and outcome events, as well as uncertainties about trial methodology, which preclude reliable assessments of the potential benefits and harms of the intervention.

AUTHORS' CONCLUSIONS

The review authors do not recommend prophylactic epidural blood patch over other treatments because there are too few trial participants to allow reliable conclusions to be drawn. However, therapeutic epidural blood patch showed a benefit over conservative treatment, based on the limited available evidence.