Effects of thoracic epidural anesthesia on survival and microcirculation in severe acute pancreatitis: a randomized experimental trial

Thoracic epidural analgesia in intensive care unit patients with acute pancreatitis: the EPIPAN multicenter randomized controlled trial

BACKGROUND

Findings from preclinical studies and one pilot clinical trial suggest potential benefits of epidural analgesia in acute pancreatitis. We aimed to assess the efficacy of thoracic epidural analgesia, in addition to usual care, in improving clinical outcomes of intensive care unit patients with acute pancreatitis.

METHODS

A multicenter, open-label, randomized, controlled trial including adult patients with a clinical diagnosis of acute pancreatitis upon admission to the intensive care unit. Participants were randomly assigned (1:1) to a strategy combining thoracic epidural analgesia and usual care (intervention group) or a strategy of usual care alone (control group). The primary outcome was the number of ventilator-free days from randomization until day 30.

RESULTS

Between June 2014 and January 2019, 148 patients were enrolled, and 135 patients were included in the intention-to-treat analysis, with 65 patients randomly assigned to the intervention group and 70 to the control group. The number of ventilator-free days did not differ significantly between the intervention and control groups (median [interquartile range], 30 days [15-30] and 30 days [18-30], respectively; median absolute difference of - 0.0 days, 95% CI - 3.3 to 3.3; p = 0.59). Epidural analgesia was significantly associated with longer duration of invasive ventilation (median [interquartile range], 14 days [5-28] versus 6 days [2-13], p = 0.02).

CONCLUSIONS

In a population of intensive care unit adults with acute pancreatitis and low requirement for intubation, this first multicenter randomized trial did not show the hypothesized benefit of epidural analgesia in addition to usual care. Safety of epidural analgesia in this setting requires further investigation.

TRIAL REGISTRATION

ClinicalTrials.gov registration number NCT02126332 , April 30, 2014.

The safety and efficacy of epidural anaesthesia in acute pancreatitis: a systematic review and meta-analysis

BACKGROUND

Acute pancreatitis (AP) has variable clinical courses. This systematic review and meta-analysis aimed to determine the safety, efficacy, and impact of epidural anaesthesia (EA) use in AP.

METHODS

The PubMed, EMBASE, SCOPUS and Cochrane library databases were systematically searched between 1980 and 2022 using the PRISMA guidelines, to identify observational and comparative studies reporting on EA in AP. The meta-analysis was performed in R Foundation for Statistical Computing using the meta R Package for Meta-Analysis.

RESULTS

A total of 9 studies with 2006 patients of which 726 (36%) patients had EA were included. All studies demonstrated high safety and feasibility of EA in AP with no reported major local or neurological complications. One randomised controlled trial demonstrated an improvement in pain severity using a 0-10 visual analogue scale (VAS) at the outset (1.6 in EA vs 3.5 in non-EA, P = 0.02) and on day 10 (0.2 in EA vs 2.33 in non-EA, P = 0.034). There was also improvement in pancreatic perfusion with EA measured with computerised tomography 13 (43%) in EA vs 2 (7%) in non-EA, P = 0.003. The need for ventilatory support and overall mortality was lower in EA patients 40 (19%) vs 285 (24%) P = 0.025 (OR: 0.49, 95% CI: 0.28-0.84) and 16 (7%) vs 214 (20%), P = 0.050 (OR: 0.39, 95% CI: 0.15-1.00), respectively.

CONCLUSION

EA is infrequently used for pain management in AP and yet the available evidence suggests that it is safe and effective in reducing pain severity, improving pancreatic perfusion, and decreasing mortality.

Impact of early thoracic epidural analgesia in patients with severe acute pancreatitis

OBJECTIVE

This study was designed to assess the impact of thoracic epidural analgesia (TEA) in patients with severe acute pancreatitis (SAP).

METHODS

This is a single-centre retrospective study. In this study, the outcomes of SAP patients were compared between patients received TEA (TEA group) and without TEA (NTEA group). Early TEA was defined as TEA performed within 48 hours after onset. The main outcome was the mortality at 30 days after ICU admission, and secondary outcomes included the incidence of acute respiratory distress syndrome (ARDS), the acute renal injury (AKI) and sepsis, the hospital stay and hospitalization expenses.

RESULTS

The mortality of SAP patients in TEA versus NTEA was 8.0% and 13.3% (p = .1520). Multivariate regression analysis showed significant difference in mortality between the TEA and NTEA groups (OR, 0.387; 95% CI, 0.168-0.892; p = .026). The incidence of ARDS in TEA versus NTEA was 46.0% and 62.4% (p = .0044); the proportion of patients requiring invasive ventilator assisted ventilation in TEA, and NTEA was 22.6% and 39.2% (p = .0016). The incidence of AKI in TEA versus NTEA was 27.7% and 45.3% (p = .0044); the proportion of patients needing for continuous renal replacement therapy (CRRT) in TEA and NTEA was 48.2% and 74.0% (p < .0001). The mortality of SAP patients in early TEA versus NTEA was 4.8% and 15.3% (p = .0263).

CONCLUSIONS

TEA was associated with low incidence of ARDS and AKI in patients with SAP. Early TEA may benefit mortality in SAP patients and is a possible protective factor for the mortality of SAP patients.

Efficacy and Safety of Thoracic Epidural Analgesia in Patients With Acute Pancreatitis: A Narrative Review

Patients admitted to the intensive care unit with moderate to severe acute pancreatitis carry significant morbidity and mortality. A few unfortunate patients in whom the initial line of treatment fails to show clinical improvement develop multiorgan dysfunction involving lungs (adult respiratory distress syndrome), renal failure, intra-abdominal infections, sepsis, and septic shock, which ultimately leads to prolonged hospitalization and a substantial cost of treatment. The acute abdominal pain experienced by these patients is excruciating and requires multimodal analgesia. Continuous epidural analgesia has been found to provide good quality, opioid-sparing analgesia in these patients. A few studies have also demonstrated that segmental sympathectomy resulting from epidural blockade could lead to lowering of serum amylase and lipase levels improve paralytic ileus, and thus hastens the process of recovery. The present paper aims to discuss the advantages of continuous epidural analgesia in patients with acute pancreatitis of varying severity and to review the existing literature using specific keywords.

The use of pulse pressure variation for predicting impairment of microcirculatory blood flow

Dynamic parameters of preload have been widely recommended to guide fluid therapy based on the principle of fluid responsiveness and with regard to cardiac output. An equally important aspect is however to also avoid volume-overload. This accounts particularly when capillary leakage is present and volume-overload will promote impairment of microcirculatory blood flow. The aim of this study was to evaluate, whether an impairment of intestinal microcirculation caused by volume-load potentially can be predicted using pulse pressure variation in an experimental model of ischemia/reperfusion injury. The study was designed as a prospective explorative large animal pilot study. The study was performed in 8 anesthetized domestic pigs (German landrace). Ischemia/reperfusion was induced during aortic surgery. 6 h after ischemia/reperfusion-injury measurements were performed during 4 consecutive volume-loading-steps, each consisting of 6 ml kg⁻¹ bodyweight⁻¹. Mean microcirculatory blood flow (mean Flux) of the ileum was measured using direct laser-speckle-contrast-imaging. Receiver operating characteristic analysis was performed to determine the ability of pulse pressure variation to predict a decrease in microcirculation. A reduction of ≥ 10% mean Flux was considered a relevant decrease. After ischemia–reperfusion, volume-loading-steps led to a significant increase of cardiac output as well as mean arterial pressure, while pulse pressure variation and mean Flux were significantly reduced (Pairwise comparison ischemia/reperfusion-injury vs. volume loading step no. 4): cardiac output (l min⁻¹) 1.68 (1.02–2.35) versus 2.84 (2.15–3.53), p = 0.002, mean arterial pressure (mmHg) 29.89 (21.65–38.12) versus 52.34 (43.55–61.14), p < 0.001, pulse pressure variation (%) 24.84 (17.45–32.22) versus 9.59 (1.68–17.49), p = 0.004, mean Flux (p.u.) 414.95 (295.18–534.72) versus 327.21 (206.95–447.48), p = 0.006. Receiver operating characteristic analysis revealed an area under the curve of 0.88 (CI 95% 0.73–1.00; p value < 0.001) for pulse pressure variation for predicting a decrease of microcirculatory blood flow. The results of our study show that pulse pressure variation does have the potential to predict decreases of intestinal microcirculatory blood flow due to volume-load after ischemia/reperfusion-injury. This should encourage further translational research and might help to prevent microcirculatory impairment due to excessive fluid resuscitation and to guide fluid therapy in the future.

Effectiveness of thoracic epidural anesthesia in reducing morbidity and mortality in adults with acute pancreatitis: a systematic review protocol and meta-analysis

OBJECTIVE

The objective of this review is to evaluate the effectiveness of thoracic epidural in reducing morbidity and mortality in adults with acute pancreatitis.

INTRODUCTION

Acute pancreatitis is a common disease that often results in significant morbidity and mortality. Although the use of a thoracic epidural anesthesia in patients with acute pancreatitis provides effective analgesia, there appears to be additional non-analgesic benefits associated with thoracic epidural anesthesia.

INCLUSION CRITERIA

Randomized controlled trials will be sought for inclusion, but this review will also consider quasi-experimental studies, cohort studies, case-controlled studies, cross-sectional studies, and case-series studies. Studies will include patients 18 years of age and older with acute pancreatitis, with no exclusion to comorbidity. Studies published in a language other than English will be excluded unless a translated version is available.

METHODS

The key databases to be searched include MEDLINE, CINAHL, OpenGrey, ClinicalTrials.gov, and Google Scholar. Studies will be assessed for inclusion by at least two independent reviewers. Included studies will be critically appraised by two independent reviewers using standardized critical appraisal instruments from JBI. Data will be extracted from studies included in the review using a standardized extraction tool. Studies will, where possible, be pooled in statistical meta-analysis using JBI SUMARI.

SYSTEMATIC REVIEW REGISTRATION NUMBER

The title of this protocol has been registered with the JBI Systematic Review Register. This manuscript has been registered with PROSPERO (CRD42020177756).

New insights into acute pancreatitis

The incidence of acute pancreatitis continues to increase worldwide, and it is one of the most common gastrointestinal causes for hospital admission in the USA. In the past decade, substantial advancements have been made in our understanding of the pathophysiological mechanisms of acute pancreatitis. Studies have elucidated mechanisms of calcium-mediated acinar cell injury and death and the importance of store-operated calcium entry channels and mitochondrial permeability transition pores. The cytoprotective role of the unfolded protein response and autophagy in preventing sustained endoplasmic reticulum stress, apoptosis and necrosis has also been characterized, as has the central role of unsaturated fatty acids in causing pancreatic organ failure. Characterization of these pathways has led to the identification of potential molecular targets for future therapeutic trials. At the patient level, two classification systems have been developed to classify the severity of acute pancreatitis into prognostically meaningful groups, and several landmark clinical trials have informed management strategies in areas of nutritional support and interventions for infected pancreatic necrosis that have resulted in important changes to acute pancreatitis management paradigms. In this Review, we provide a summary of recent advances in acute pancreatitis with a special emphasis on pathophysiological mechanisms and clinical management of the disorder.

Current Concepts in Severe Acute and Necrotizing Pancreatitis: An Evidence-Based Approach

The incidence of acute pancreatitis continues to rise, inducing substantial medical and social burden, with annual costs exceeding $2 billion in the United States alone. Although most patients develop mild pancreatitis, 20% develop severe and/or necrotizing pancreatitis, requiring advanced medical and interventional care. Morbidity resulting from local and systemic complications as well as invasive interventions result in mortality rates historically as high as 30%. There has been substantial evolution of strategies for interventions in recent years, from open surgery to minimally invasive surgical and endoscopic step-up approaches. In contrast to the advances in invasive procedures for complications, early management still lacks curative options and consists of adequate fluid resuscitation, analgesics, and monitoring. Many challenges remain, including comprehensive management of the entire spectrum of the disease, which requires close involvement of multiple disciplines at specialized centers.

Regional analgesia techniques for pain management in patients admitted to the intensive care unit

Controlling pain should be a priority in the clinical practice of intensive care units (ICUs). Monomodal analgesic approaches, such as the administration of opioids, are widely employed; however, the widespread use of opioids has catastrophic consequences, given their multiple side effects and the development of dependence. Regional analgesia (RA), with single or continuous dosing using neuraxial and peripheral catheters, can play an important role in multimodal analgesia for management of pain in critical care patients. RA provides superior pain control, as compared to systemic treatments, and is associated with a lower rate of side effects. Nevertheless, RA remains underused in ICUs. Many critically ill, post-surgical or traumatically injured patients would benefit from these techniques. For these reasons, we aim to establish a set of potential indications integrating the use of RA in analgesia protocols routinely used in ICUs. We performed a review of literature sources with contrasted evidence levels to present RA techniques and their potential applications in ICU patients.

Effect of Segmental Thoracic Epidural Block on Pancreatitisinduced Organ Dysfunction: A Preliminary Study

Background

This preliminary randomized controlled study evaluated effect of thoracic epidural block (TEB) on progression of acute pancreatitis induced organ dysfunction/failure.

Materials and Methods

Patients with predicted severe acute pancreatitis, without contraindication to TEB were randomized to receive (group TE) or not receive a TEB (group NTE) (n = 16 each). For group TE, TEB was performed at T8-9 or T9-10 vertebral level, with infusion of ropivacaine (0.2%) along with fentanyl 2 µg/mL; in group NTE, intravenous morphine was used instead, both interventions titrated to NRS of <4. SOFA score was assessed daily till discharge from ICU, and aggregate SOFA calculated by summing worst scores for each of organ system during ICU stay as primary outcome measure. Other surrogate measures of patient outcome were recorded as secondary objectives.

Results

Aggregate SOFA score was statistically similar between both groups (group NTE: 3 [2 - 4]; group TE: 5 [2 - 6]) (P = 0.379); but there was trend of improvement in SOFA score in group TE versus a worsening in group NTE. Duration of hospital stay, and number of patients requiring mechanical ventilation were statistically similar; mortality was insignificantly lesser for group TE (12.5% versus 6.6%; p = 1.000). Fall in serum procalcitonin was significantly greater for group TE.

Conclusion

Thoracic epidural was associated with insignificant clinical trend towards better organ functions and lesser mortality; along with significantly greater fall in serum procalcitonin. These are encouraging results that could guide future use of thoracic epidural in acute pancreatitis for its non-analgesic benefits.

How to cite this article

Tyagi A, Gupta YR et al. Effect of Segmental Thoracic Epidural Block on Pancreatitis Induced Organ Dysfunction: A Preliminary Study. Indian J of Crit Care Med 2019;23(2):89-94.

Thoracic epidural anaesthesia reduces insulin resistance and inflammatory response in experimental acute pancreatitis

AIMS

The activity of the sympathetic nervous system (SNS) is crucial at an early stage in the development of an inflammatory reaction. A study of metabolic events globally and locally in the early phase of acute pancreatitis (AP), implying hampered SNS activity, is lacking. We hypothesized that thoracic epidural anaesthesia (TEA) modulates the inflammatory response and alleviates the severity of AP in pigs.

MATERIAL AND METHODS

The taurocholate (TC) group (n = 8) had only TC AP. The TC + TEA group (n = 8) had AP and TEA. A control group (n = 8) underwent all the preparations, without having AP or TEA. Metabolic changes in the pancreas were evaluated by microdialysis and by histopathological examination.

RESULTS

The relative increase in serum lipase concentrations was more pronounced in the TC group than in TC + TEA and control groups. A decrease in relative tissue oxygen tension (PtiO₂) levels occurred one hour later in the TC + TEA group than in the TC group. The maintenance of normoglycaemia in the TC group required a higher glucose infusion rate than in the TC + TEA group. The relative decrease in serum insulin concentrations was most pronounced in the TC + TEA group.

CONCLUSION

TEA attenuates the development of AP, as indicated by changes observed in haemodynamic parameters and by the easier maintenance of glucose homeostasis. Further, TEA was associated with attenuated insulin resistance and fewer local pathophysiological events.

Progress in research of comfort nursing in patients with severe acute pancreatitis

At present, only surgical treatment and internal conservative treatment are feasible for severe acute pancreatitis (SAP), while nursing is an important method for adjuvant therapy. Because the clinical features and treatment methods of SAP bring much discomfort and pain to the patients, traditional nursing has been unable to meet the needs of the patients for active treatment and comfort recovery. Instead, comfort care can relieve patients' pain as much as possible so that patients can, in all aspects, achieve the most pleasant and comfortable state. Therefore, the development of a comfortable care model for patients with SAP is crucial to its treatment. However, the implementation of comfort care is often restricted by factors such as unfamiliar hospitalization environment, patients' family, social support, economic conditions, the disease itself, and treatment. Thus, long-term development of comfort care can be achieved only after restrictive factors are solved. This article reviews the factors affecting the comfort of patients with SAP and the corresponding countermeasures.

Epidural analgesia in critically ill patients with acute pancreatitis: the multicentre randomised controlled EPIPAN study protocol

BACKGROUND

Acute pancreatitis (AP) is associated with high morbidity and mortality in its most severe forms. Most patients with severe AP require intubation and invasive mechanical ventilation, frequently for more than 7 days, which is associated with the worst outcome. Recent increasing evidence from preclinical and clinical studies support the beneficial effects of epidural analgesia (EA) in AP, such as increased gut barrier function and splanchnic, pancreatic and renal perfusion, decreased liver damage and inflammatory response, and reduced mortality. Because recent studies suggest that EA might be a safe procedure in the critically ill, we sought to determine whether EA reduced AP-associated respiratory failure and other major clinical outcomes in patients with AP.

METHODS AND ANALYSIS

The Epidural Analgesia for Pancreatitis (EPIPAN) trial is an investigator-initiated, prospective, multicentre, randomised controlled two-arm trial with assessor-blinded outcome assessment. The EPIPAN trial will randomise 148 patients with AP requiring admission to an intensive care unit (ICU) to receive EA (with patient-controlled epidural administration of ropivacaine and sufentanil) combined with standard care based on current recommendations on the treatment of AP (interventional group), or standard care alone (reference group). The primary outcome is the number of ventilator-free days at day 30. Secondary outcomes include main complications of AP (eg, organ failure and mortality, among others), levels of biological markers of systemic inflammation, epithelial lung injury, renal failure, and healthcare-associated costs.

ETHICS AND DISSEMINATION

The study was approved by the appropriate ethics committee (CPP Sud-Est VI). Informed consent is required. If the combined application of EA and standard care proves superior to standard care alone in patients with AP in the ICU, the use of EA may become standard practice in experienced centres, thereby decreasing potential complications related to AP and its burden in critically ill patients. The results will be disseminated in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT02126332.

Thoracic epidural analgesia reduces gastric microcirculation in the pig

Background

Thoracic epidural analgesia (TEA) is used for pain relief during and after abdominal surgery, but the effect of TEA on the splanchnic microcirculation remains debated. We evaluated whether TEA affects splanchnic microcirculation in the pig.

Methods

Splanchnic microcirculation was assessed in nine pigs prior to and 15 and 30 min after induction of TEA. Regional blood flow was assessed by neutron activated microspheres and changes in microcirculation by laser speckle contrast imaging (LSCI).

Results

As assessed by LSCI 15 min following TEA, gastric arteriolar flow decreased by 22 % at the antrum (p = 0.020) and by 19 % at the corpus (p = 0.029) of the stomach. In parallel, the microcirculation decreased by 19 % at the antrum (p = 0.015) and by 20 % at the corpus (p = 0.028). Reduced arteriolar flow and microcirculation at the antrum was confirmed by a reduction in microsphere assessed regional blood flow 30 min following induction of TEA (p = 0.048). These manifestations took place along with a drop in systolic blood pressure (p = 0.030), but with no significant change in mean arterial pressure, cardiac output, or heart rate.

Conclusion

The results indicate that TEA may have an adverse effect on gastric arteriolar blood flow and microcirculation. LSCI is a non-touch technique and displays changes in blood flow in real-time and may be important for further evaluation of the concern regarding the effect of thoracic epidural anesthesia on gastric microcirculation in humans.

Trial registrations

Not applicable, non-human study.

Thoracic epidural analgesia: a new approach for the treatment of acute pancreatitis?

This review article analyzes, through a nonsystematic approach, the pathophysiology of acute pancreatitis (AP) with a focus on the effects of thoracic epidural analgesia (TEA) on the disease. The benefit-risk balance is also discussed. AP has an overall mortality of 1 %, increasing to 30 % in its severe form. The systemic inflammation induces a strong activation of the sympathetic system, with a decrease in the blood flow supply to the gastrointestinal system that can lead to the development of pancreatic necrosis. The current treatment for severe AP is symptomatic and tries to correct the systemic inflammatory response syndrome or the multiorgan dysfunction. Besides the removal of gallstones in biliary pancreatitis, no satisfactory causal treatment exists. TEA is widely used, mainly for its analgesic effect. TEA also induces a targeted sympathectomy in the anesthetized region, which results in splanchnic vasodilatation and an improvement in local microcirculation. Increasing evidence shows benefits of TEA in animal AP: improved splanchnic and pancreatic perfusion, improved pancreatic microcirculation, reduced liver damage, and significantly reduced mortality. Until now, only few clinical studies have been performed on the use of TEA during AP with few available data regarding the effect of TEA on the splanchnic perfusion. Increasing evidence suggests that TEA is a safe procedure and could appear as a new treatment approach for human AP, based on the significant benefits observed in animal studies and safety of use for human. Further clinical studies are required to confirm the clinical benefits observed in animal studies.

Time Trend of Outcomes for Severe Acute Pancreatitis After Publication of Japanese Guidelines Based on a National Administrative Database

OBJECTIVES

This study aimed to investigate the recent time trend of outcomes for severe acute pancreatitis after publication of Japanese guidelines based on a national administrative database.

METHODS

A total of 10,400 patients with severe acute pancreatitis were referred to 1021 hospitals between 2010 and 2012 in Japan. We collected patients' data from the administrative database to compare in-hospital mortality (within 28 days and overall), length of stay (LOS), and medical costs during hospitalization. The study periods were categorized into 3 groups according to fiscal year: 2010 (n = 2698), 2011 (n = 3842), and 2012 (n = 3860).

RESULTS

In-hospital mortality within 28 days and overall in-hospital mortality were significantly decreased according to fiscal year (6.3% [2010] vs 5.7% [2011] vs 4.5% [2012], P = 0.005; 7.6% vs 7.1% vs 5.6%, P = 0.002, respectively). However, mean LOS and medical costs were not different between fiscal years (27.0 vs 27.1 vs 26.9 days, P = 0.218; 13,998.0 vs 14,156.4 vs 14,319.2 USD, P = 0.232, respectively).

CONCLUSIONS

This study shows that mortality of severe acute pancreatitis was reduced according to the time course, whereas LOS or medical costs were stable after publication of the Japanese guidelines.

The Effects of Pancreatic Microcirculatory Disturbances on Histopathologic Tissue Damage and the Outcome in Severe Acute Pancreatitis

OBJECTIVES

Severe acute pancreatitis is an inflammatory disease of the pancreas with a high morbidity and mortality. To date, no causal treatment is known. The aim of the present study was to analyze the impact of pancreatic microcirculatory disturbances in severe acute pancreatitis and to correlate the effects with histopathologic tissue damage and outcome.

METHODS

Severe acute pancreatitis was induced in 129 pigs by injection of glycodeoxycholic acid into the pancreatic duct. Pancreatic microcirculation, pancreatic tissue oxygenation, histopathologic tissue damage, and survival were measured and analyzed.

RESULTS

Our study demonstrates a strong correlation between pancreatic microcirculatory disturbances and histopathologic tissue damage (r = 0.728; P < 0.001). Furthermore, we showed a strong correlation between tissue oxygenation and the severity of the pancreatitis according to an established porcine pancreatitis score (r = 0.694; P < 0.001). In addition, disturbances of the pancreatic microcirculation were shown to be associated with an increased mortality rate in severe acute pancreatitis.

CONCLUSIONS

We found that pancreatic microcirculatory disturbances have significant effects on histopathologic tissue damage and the outcome of severe acute pancreatitis. For a better survival of severe acute pancreatitis, the treatment should focus on an improvement of pancreatic microcirculation.

Management of Acute Pancreatitis in the Early Stage

Acute pancreatitis (AP) is a potential fatal disease with an overall mortality around 5%. The current treatment for AP relies on supportive medical therapy, sometimes associated with endoscopic procedures and/or surgical interventions. In this review we discuss the recent concepts regarding the fluid therapy, pain management, antibiotic prophylaxis, apheresis for hypertriglyceridemia-induced AP, timing and indications for ERCP and cholecystectomy in biliary AP. For each component, the importance and the impact of early phase treatment is presented in terms of benefits and risks.

Thoracic epidural anesthesia: Effects on splanchnic circulation and implications in Anesthesia and Intensive care

AIM: To evaluate the currently available evidence on thoracic epidural anesthesia effects on splanchnic macro and microcirculation, in physiologic and pathologic conditions.

METHODS: A PubMed search was conducted using the MeSH database. Anesthesia, Epidural was always the first MeSH heading and was combined by boolean operator AND with the following headings: Circulation, Splanchnic; Intestines; Pancreas and Pancreatitis; Liver Function Tests. EMBASE, Cochrane library, ClinicalTrials.gov and clinicaltrialsregister.eu were also searched using the same terms.

RESULTS: Twenty-seven relevant studies and four ongoing trials were found. The data regarding the effects of epidural anesthesia on splanchnic perfusion are conflicting. The studies focusing on regional macro-hemodynamics in healthy animals and humans undergoing elective surgery, demonstrated no influence or worsening of regional perfusion in patients receiving thoracic epidural anesthesia (TEA). On the other hand most of the studies focusing on micro-hemodynamics, especially in pathologic low flow conditions, suggested that TEA could foster microcirculation.

CONCLUSION: The available studies in this field are heterogeneous and the results conflicting, thus it is difficult to draw decisive conclusions. However there is increasing evidence deriving from animal studies, that thoracic epidural blockade could have an important role in modifying tissue microperfusion and protecting microcirculatory weak units from ischemic damage, regardless of the effects on macro-hemodynamics.

The role of thoracic epidural anesthesia in severe acute pancreatitis

In animal studies of severe acute pancreatitis, thoracic epidural anesthesia appears to enhance the splanchnic circulation, improve end-organ perfusion, and favorably influence mortality. The application of thoracic epidurals in the critically ill human patient is less clear. Methodological difficulties in reliably assessing mesenteric flow have hampered progress, and clinical concerns surrounding this potentially attractive therapeutic modality remain unanswered. Future research needs to focus on the impact of epidural anesthesia on basic human physiological pmeters to help direct further randomized studies in human disease.