Obesity in regional anesthesia--a risk factor for peripheral catheter-related infections

Regional analgesia catheter-related infections and the effectiveness of antibiotic prophylaxis in immunocompromised patients: A retrospective multicenter registry analysis

BACKGROUND

The risk of regional analgesia catheter-related infections in immunocompromised patients remains uncertain. We therefore tested the hypotheses that catheter-related infections appear earlier and are more severe, and that antibiotic prophylaxis is more effective in immunocompromised than immunocompetent patients.

METHODS

Data were extracted from the Network for Safety in Regional Anesthesia and Acute Pain Therapy (net-ra) registry from 2007 to 2022. We used multivariable cox and ordinal regression to assess the effect of immune function and antibiotic prophylaxis indicated by surgery on infection onset and severity.

RESULTS

We analyzed data from 196,711 catheters, including 1347 in immunocompromised patients. Infection severities in immunocompetent patients were none (190,220 (97.4 %)), mild (4517 (2.3 %)), and moderate/severe (627 (0.3 %)). In immunocompromised patients, infection severities were none (1285 (95.4 %)), mild (58 (4.3 %)), and moderate/severe (4 (0.3 %)). Immunocompromised patients who were not given antibiotics had a 29 % greater infection hazard (HR 1.29 [95 %CI: 0.95, 1.76], p = 0.1) and 91 % greater odds of higher infection severities (OR 1.91 [95 %CI: 1.39, 2.63], p < 0.001). Antibiotics were more effective in delaying infection onset (HR 0.65 [95 %CI: 0.38, 1.12], p = 0.12) and preventing infection (OR 0.54 [95 %CI: 0.31, 0.94], p = 0.029) in immunocompromised than immunocompetent patients. The number of patients needed-to-treat to prevent an infection with antibiotics was 55 in immunocompromised patients versus 83 in immunocompetent patients.

CONCLUSIONS

Regional analgesia catheter-related infections occur slightly earlier and are more frequent in immunocompromised patients. Antibiotics are marginally effective for catheter infection prophylaxis and should be restricted to patients who are severely immunocompromised with and at special risks.

ASRA Pain Medicine consensus practice infection control guidelines for regional anesthesia and pain medicine

BACKGROUND

To provide recommendations on risk mitigation, diagnosis and treatment of infectious complications associated with the practice of regional anesthesia, acute and chronic pain management.

METHODS

Following board approval, in 2020 the American Society of Regional Anesthesia and Pain Medicine (ASRA Pain Medicine) commissioned evidence-based guidelines for best practices for infection control. More than 80 research questions were developed and literature searches undertaken by assigned working groups comprising four to five members. Modified US Preventive Services Task Force criteria were used to determine levels of evidence and certainty. Using a modified Delphi method, >50% agreement was needed to accept a recommendation for author review, and >75% agreement for a recommendation to be accepted. The ASRA Pain Medicine Board of Directors reviewed and approved the final guidelines.

RESULTS

After documenting the incidence and infectious complications associated with regional anesthesia and interventional pain procedures including implanted devices, we made recommendations regarding the role of the anesthesiologist and pain physician in infection control, preoperative patient risk factors and management, sterile technique, equipment use and maintenance, healthcare setting (office, hospital, operating room), surgical technique, postoperative risk reduction, and infection symptoms, diagnosis, and treatment. Consensus recommendations were based on risks associated with different settings and procedures, and keeping in mind each patient's unique characteristics.

CONCLUSIONS

The recommendations are intended to be multidisciplinary guidelines for clinical care and clinical decision-making in the regional anesthesia and chronic interventional pain practice. The issues addressed are constantly evolving, therefore, consistent updating will be required.

Risk profiles of common brachial plexus block sites: results from the net-ra registry

INTRODUCTION

Regional anesthesia is frequently used for upper limb surgeries and postoperative pain control. Different approaches to brachial plexus blocks are similarly effective but may differ in the frequency and severity of iatrogenesis. We, therefore, examined large-scale registry data to explore the risks of typical complications among different brachial plexus block sites for regional anesthesia.

METHODS

26,947 qualifying adult brachial plexus blocks (2007-2022) from the Network for Safety in Regional Anesthesia and Acute Pain Therapy registry were included in a retrospective cohort analysis. Interscalene, supraclavicular, infraclavicular, and axillary approaches were compared for block failure and bloody punctures using generalized estimating equations. For continuous procedures, we analyzed the influence of the approach on catheter failure, neurological disorders, and infections.

RESULTS

The axillary plexus block had the highest risk of block failure (adjusted OR, 2.3; 95% CI 1.02 to 5.1; p=0.04), catheter failure (adjusted OR, 1.4; 95% CI 1.1 to 2.0; p=0.02), and neurological dysfunction (adjusted OR, 3.0; 95% CI 1.5 to 5.9; p=0.002). There was no statistically significant difference among block sites for bloody punctures, while infraclavicular blocks had the highest odds for catheter-related infections.

DISCUSSION

The axillary approach to the brachial plexus had the highest odds for block failure and neurological dysfunction after catheter placement, as well as a significant risk for catheter failure. However, considering that the axillary approach precludes other complications such as pneumothorax, none of the four common approaches to the brachial plexus has a fundamentally superior risk profile.

A prospective randomized trial comparing the efficacy of temperature-responsive gel with local anesthetics versus local anesthetic infusion pump device for postoperative pain control after bariatric surgery

Purpose

Bariatric surgery is the gold standard for the treatment of morbid obesity, but postoperative pain impedes recovery. Currently available pain-recovery treatments have patient safety concerns. This led to a noninferiority study of Welpass (Genewel Co., Ltd.) vs. On-Q PainBuster (B. Braun), each used alongside a traditional method of continuous local anesthetic administration, in patients undergoing bariatric surgery.

Methods

In this single-center prospective randomized clinical trial, patients were assigned in a 1:1 ratio to the treatment group (Welpass) and the control group (On-Q PainBuster), with ketorolac administered as needed after surgery according to the protocol. To assess efficacy, the total amount of ketorolac used up to 72 hours postoperatively was measured. Additionally, ketorolac usage and numerical rating scales (NRS) were recorded at 6, 24, 48, and 72 hours after operation.

Results

The total amounts of ketorolac used in the 72 hours postoperatively were 188.0 ± 84.6 mg in the treatment group and 198.7 ± 50.0 mg in the control group. The efficacy of the treatment group was noninferior to that of the control group, since the lower limit (-29.9 mg) of the confidence interval for the difference with the control group was greater than the prespecified noninferiority margin (-35.0 mg). Furthermore, when the NRS was evaluated after bariatric surgery, there was no significant difference in scores between the 2 groups at each time point (P > 0.05).

Conclusion

We found no difference in effect on pain between the 2 groups, supporting the use of Welpass in clinical practice for pain management in patients undergoing bariatric surgery.

Infectious complications following regional anesthesia: a narrative review and contemporary estimates of risk

INTRODUCTION

Infectious complications following regional anesthesia (RA) while rare, can be devastating. The objective of this review was to estimate the risk of infectious complications following central neuraxial blocks (CNB) such as epidural anesthesia (EA), spinal anesthesia (SA) and combined spinal epidural (CSE), and peripheral nerve blocks (PNB).

MATERIALS AND METHODS

A literature search was conducted in PubMed, Embase and Cochrane databases to identify reference studies reporting infectious complications in the context of RA subtypes. Both prospective and retrospective studies providing incidence of infectious complications were included for review to provide pooled estimates (with 95% CI). Additionally, we explored incidences specifically associated with spinal anesthesia, incidences of central nervous system (CNS) infections and, the incidences of overall and CNS infections following CNB in obstetric population.

RESULTS

The pooled estimate of overall infectious complications following all CNB was 9/100 000 (95% CI: 5, 13/100 000). CNS infections following all CNB was estimated to be 2/100 000 (95% CI: 1, 3/100 000) and even rarer following SA (1/100 000 (95% CI: 1, 2/100 000)). Obstetric population had a lower rate of overall (1/100 000 (95% CI: 1, 3/100 000)) and CNS infections (4 per million (95% CI: 0.3, 1/100 000)) following all CNB. For PNB catheters, the reported rate of infectious complications was 1.8% (95% CI: 1.2, 2.5/100).

DISCUSSION

Our review suggests that the risk of overall infectious complications following neuraxial anesthesia is very rare and the rate of CNS infections is even rarer. The infectious complications following PNB catheters seems significantly higher compared with CNB. Standardizing nomenclature and better reporting methodologies are needed for the better estimation of the infectious complications.

Continuous Catheter Techniques

Continuous peripheral nerve block catheters are simple in concept: percutaneously inserting a catheter adjacent to a peripheral nerve. This procedure is followed by local anesthetic infusion via the catheter that can be titrated to effect for extended anesthesia or analgesia in the perioperative period. The reported benefits of peripheral nerve catheters used in the surgical population include improved pain scores, decreased narcotic use, decreased nausea/vomiting, decreased pruritus, decreased sedation, improved sleep, and improved patient satisfaction.

Continuous Catheter Techniques

Continuous peripheral nerve block catheters are simple in concept: percutaneously inserting a catheter adjacent to a peripheral nerve. This procedure is followed by local anesthetic infusion via the catheter that can be titrated to effect for extended anesthesia or analgesia in the perioperative period. The reported benefits of peripheral nerve catheters used in the surgical population include improved pain scores, decreased narcotic use, decreased nausea/vomiting, decreased pruritus, decreased sedation, improved sleep, and improved patient satisfaction.

Dyspnea induced by hemidiaphragmatic paralysis after ultrasound-guided supraclavicular brachial plexus block in a morbidly obese patient

RATIONALE

Hemidiaphragmatic paralysis (HDP) is a frequent complication of the brachial plexus block, caused by unintentional blockade of ipsilateral phrenic nerve. HDP did not rise enough alarm and attention to most anesthesiologists, because most patients with no coexisting comorbid diseases are asymptomatic and able to tolerate it. However, it may cause severe respiratory complication for patients with preexisting compromised cardiorespiratory function.

PATIENT CONCERNS

A 67-year-old woman with morbidly obesity was planned to receive opening reduction and internal fixation of right humeral shaft fracture under regional anesthesia considering less respiratory and cardiovascular system interference compared with general anesthesia.

DIAGNOSES

After ultrasound guided supraclavicular brachial plexus block, the patient developed severe hypoxia and hypercapnia.Unintentional block of phrenic nerve and diaphragm paralysis was diagnosed by diaphragm ultrasound, which was considered as the main reason of severe hypoxia.

INTERVENTIONS

It led to a conversion from regional anesthesia to general anesthesia with endotracheal intubation for patient's safety and smooth operation.

OUTCOMES

The unintentional phrenic nerve block leads to a prolonged ventilation time, length of stay in intensive care unit and length of stay in hospital.

LESSONS

This case report highlights the risk of diaphragm paralysis in morbidly obese patients. Though new diaphragm sparing brachial plexus block (BPB) methods were developed intended to reduce the risk of HDP, no approaches could absolutely spare phrenic nerve involvement. Therefore, clinicians should always consider the risk of HDP associated with BPBs. For each individual, a detailed preoperative evaluation and sufficient preparation are paramount to avoid serious complications.

[Peripheral Regional Anaesthesia for Perioperative Analgesia]

Peripheral Regional Anaesthesia for Perioperative Analgesia Abstract. Peripheral regional anaesthesia is the actual gold standard of opioid-sparing perioperative analgesia and is mainly used for surgery of the shoulder, arm and leg. Well-trained anaesthesiologists are the prerequisite for the correct individual risk-benefit assessment and the performance of the nerve blocks using a combination of ultrasound guidance and peripheral nerve stimulation (dual guidance). The postoperative care of the patients requires trained staff.

Big Data in Studying Acute Pain and Regional Anesthesia

The digital transformation of healthcare is advancing, leading to an increasing availability of clinical data for research. Perioperative big data initiatives were established to monitor treatment quality and benchmark outcomes. However, big data analyses have long exceeded the status of pure quality surveillance instruments. Large retrospective studies nowadays often represent the first approach to new questions in clinical research and pave the way for more expensive and resource intensive prospective trials. As a consequence, the utilization of big data in acute pain and regional anesthesia research has considerably increased over the last decade. Multicentric clinical registries and administrative databases (e.g., healthcare claims databases) have collected millions of cases until today, on which basis several important research questions were approached. In acute pain research, big data was used to assess postoperative pain outcomes, opioid utilization, and the efficiency of multimodal pain management strategies. In regional anesthesia, adverse events and potential benefits of regional anesthesia on postoperative morbidity and mortality were evaluated. This article provides a narrative review on the growing importance of big data for research in acute postoperative pain and regional anesthesia.

Regional anaesthesia in patients with diabetes

Diabetes is the most common metabolic condition worldwide and about 20% of surgical patients will have this condition. It is a major risk-factor for worse outcomes after surgery including mortality; infective and non-infective complications; and increased length of stay. However, diabetes is a modifiable risk-factor, and programs to improve medical management have the potential to reduce peri-operative complications and the risk of harm. Regional anaesthesia has well-documented benefits in promoting the restoration of function but there are legitimate concerns that the incidence of complications of regional anaesthesia in patients with diabetes is higher. The aim of this review is to explore in detail the various potential advantages and disadvantages of regional anaesthesia in patients with diabetes. This, in turn, will allow practitioners to undertake more informed shared decision-making and potentially modify their anaesthetic technique for patients with diabetes.

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.

Anesthesia for the Morbidly Obese Patient

Obesity is considered a major comorbidity, and it is imperative for an anesthesiologist to put increased emphasis on preoperative evaluation and perioperative management. A multidisciplinary team approach is the key for a successful outcome. This article encompasses basic tenets like pathophysiology and pharmacology pertaining to obesity. The authors also talk about important aspects of anesthesia care starting from preoperative assessment and optimization, intraoperative challenges and care, to recovery and discharge of these patients.

Prolonged Catheter Use and Infection in Regional Anesthesia: A Retrospective Registry Analysis

BACKGROUND

Prolonged catheter use is controversial because of the risk of catheter-related infection, but the extent to which the risk increases over time remains unknown. We thus assessed the time-dependence of catheter-related infection risk up to 15 days.

METHODS

Our analysis was based on the German Network for Regional Anesthesia, which includes 25 centers. We considered 44,555 patients who had surgery between 2007 and 2014 and had continuous regional anesthesia as well as complete covariable details. Cox regression analysis was performed and adjusted for confounding covariables to examine the relationship between catheter duration and probability of infection-free catheter use.

RESULTS

After adjustment for confounding factors, the probability of infection-free catheter use decreases with each day of peripheral and epidural catheter use. In peripheral catheters, it was 99% at day 4 of catheter duration, 96% at day 7, and 73% at day 15. In epidural catheters, it was 99% at day 4 of catheter duration, 95% at day 7, and 73% at day 15. Only 31 patients (0.07%) had severe infections that prompted surgical intervention. Among these were five catheters that initially had only mild or moderate signs of infection and were left in situ; all progressed to severe infections.

CONCLUSIONS

Infection risk in catheter use increases over time, especially after four days. Infected catheters should be removed as soon as practical.

VISUAL ABSTRACT

An online visual overview is available for this article at http://links.lww.com/ALN/B683.

Psoas Versus Femoral Blocks: A Registry Analysis of Risks and Benefits

BACKGROUND AND OBJECTIVES

Psoas blocks are an alternative to femoral nerve blocks and have the potential advantage of blocking the entire lumbar plexus. However, the psoas muscle is located deeply, making psoas blocks more difficult than femoral blocks. In contrast, while femoral blocks are generally easy to perform, the inguinal region is prone to infection. We thus tested the hypothesis that psoas blocks are associated with more insertion-related complications than femoral blocks but have fewer catheter-related infections.

METHODS

We extracted 22,434 surgical cases from the German Network for Regional Anesthesia registry (2007-2014) and grouped cases as psoas (n = 7593) and femoral (n = 14,841) blocks. Insertion-related complications (including single-shot blocks and catheter) and infectious complications (including only catheter) in each group were compared with χ tests. The groups were compared with multivariable logistic models, adjusted for potential confounding factors.

RESULTS

After adjustment for potential confounding factors, psoas blocks were associated with more complications than femoral blocks including vascular puncture 6.3% versus 1.1%, with an adjusted odds ratio (aOR) of 3.6 (95% confidence interval [CI], 2.9-4.6; P < 0.001), and multiple skin punctures 12.6% versus 7.7%, with an aOR of 2.6 (95% CI, 2.1-3.3; P <0.001). Psoas blocks were also associated with fewer catheter-related infections: 0.3% versus 0.9% (aOR of 0.4; 95% CI, 0.2-0.8; P = 0.016), and with improved patient satisfaction (mean ± SD 0- to 10-point scale score, 9.6 ± 1.2 vs 8.4 ± 2.9; P < 0.001). Results from a propensity-matched sensitivity analysis were similar.

CONCLUSIONS

Psoas blocks are associated with more insertion-related complications but fewer infectious complications.

CLINICAL TRIAL REGISTRATION

ID NCT02846610.

The obese patient undergoing nonbariatric surgery

PURPOSE OF REVIEW

This article provides the reader with recent findings on the pathophysiology of comorbidities in the obese, as well as evidence-based treatment options to deal with perioperative respiratory challenges.

RECENT FINDINGS

Our understanding of obesity-associated asthma, obstructive sleep apnea, and obesity hypoventilation syndrome is still expanding. Routine screening for obstructive sleep apnea using the STOP-Bang score might identify high-risk patients that benefit from perioperative continuous positive airway pressure and close postoperative monitoring. Measures to most effectively support respiratory function during induction of and emergence from anesthesia include optimal patient positioning and use of noninvasive positive pressure ventilation. Appropriate mechanical ventilation settings are under investigation, so that only the use of protective low tidal volumes could be currently recommended. A multimodal approach consisting of adjuvants, as well as regional anesthesia/analgesia techniques reduces the need for systemic opioids and related respiratory complications.

SUMMARY

Anesthesia of obese patients for nonbariatric surgical procedures requires knowledge of typical comorbidities and their respective treatment options. Apart from cardiovascular diseases associated with the metabolic syndrome, awareness of any pulmonary dysfunction is of paramount. A multimodal analgesia approach may be useful to reduce postoperative pulmonary complications.

Single-dose Antibiotic Prophylaxis in Regional Anesthesia

Background

Catheter-related infection is a serious complication of continuous regional anesthesia. The authors tested the hypothesis that single-dose antibiotic prophylaxis is associated with a lower incidence of catheter-related infections.

Methods

Our analysis was based on cases in the 25-center German Network for Regional Anesthesia database recorded between 2007 and 2014. Forty thousand three hundred sixty-two surgical patients who had continuous regional anesthesia were grouped into no antibiotic prophylaxis (n = 15,965) and single-dose antibiotic prophylaxis (n = 24,397). Catheter-related infections in each group were compared with chi-square test after 1:1 propensity-score matching. Odds ratios (ORs [95% CI]) were calculated with logistic regression and adjusted for imbalanced variables (standardized difference more than 0.1).

Results

Propensity matching successfully paired 11,307 patients with single-dose antibiotic prophylaxis (46% of 24,397 patients) and with 11,307 controls (71% of 15,965 patients). For peripheral catheters, the incidence without antibiotics (2.4%) was greater than with antibiotic prophylaxis (1.1%, P &lt; 0.001; adjusted OR, 2.02; 95% CI, 1.49 to 2.75, P &lt; 0.001). Infections of epidural catheters were also more common without antibiotics (5.2%) than with antibiotics (3.1%, P &lt; 0.001; adjusted OR, 1.94; 95% CI, 1.55 to 2.43, P &lt; 0.001).

Conclusions

Single-dose antibiotic prophylaxis was associated with fewer peripheral and epidural catheter infections.

Obesity in critically ill patients is associated with increased need of mechanical ventilation but not with mortality

Worldwide incidence of obesity is increasing and impaired outcome in postoperative patients has been described. Antibiotic prescribing is complicated by different pharmacology in this population. This study evaluates mortality and morbidity of obese postoperative patients and explores possible relation to antibiotic therapy. Therefore, data obtained in a prospective study in 2009-2010 were analysed. Postoperative patients on 5 ICUs were included with >48h of ICU treatment and documented body-mass-index (BMI). Altogether 451 non-obese patients (BMI<30kg/m(2)) were compared with 130 obese patients including propensity score matching. There was significant heterogeneity of baseline characteristics. ICU-mortality was 7.5% in non-obese and 7.7% in obese patients (p>0.999), but 65.4% of obese patients required mechanical ventilation compared with only 53.2% of non-obese patients (p=0.016). These findings were validated in multivariate regression analyses (adjusted OR for ICU-mortality for obese patients 0.53, 95%-CI 0.188-1.321, p=0.197; adjusted OR for mechanical ventilation 1.841, 95%-CI 1.113-3.076, p=0.018). Results were confirmed by propensity score matching. Therapeutic drug monitoring for vancomycin (TDM) showed that underdosing and overdosing occurred more often in obese patients and sufficient TDM levels were less often achieved. In conclusion, obesity is associated with increased morbidity but ICU mortality is equal compared with a non-obese population. Pharmacological differences might explain observed differences in antibiotic therapy and in obese patients TDM might be especially of importance.