Effect of epidural anesthesia on colorectal anastomosis: a tonometric assessment

Short-Term Outcomes of Epidural Analgesia in Minimally Invasive Esophagectomy for Esophageal Cancer: Nationwide Inpatient Data Study in Japan

BACKGROUND

Studies have shown that epidural analgesia (EDA) is associated with a decreased risk of pneumonia and anastomotic leakage after esophagectomy, and several guidelines strongly recommend EDA use after esophagectomy. However, the benefit of EDA use in minimally invasive esophagectomy (MIE) remains unclear.

OBJECTIVE

The aim of this retrospective study was to compare the short-term outcomes between patients with and without EDA undergoing MIE for esophageal cancer.

METHODS

Data of patients who underwent oncologic MIE (April 2014-March 2019) were extracted from a Japanese nationwide inpatient database. Stabilized inverse probability of treatment weighting (IPTW), propensity score matching, and instrumental variable analyses were performed to investigate the associations between EDA use and short-term outcomes, adjusting for potential confounders.

RESULTS

Among 12,688 eligible patients, EDA was used in 9954 (78.5%) patients. In-hospital mortality, respiratory complications, and anastomotic leakage occurred in 230 (1.8%), 2139 (16.9%), and 1557 (12.3%) patients, respectively. In stabilized IPTW, EDA use was significantly associated with decreased in-hospital mortality (odds ratio [OR] 0.46 [95% confidence interval 0.34-0.61]), respiratory complications (OR 0.74 [0.66-0.84]), and anastomotic leakage (OR 0.77 [0.67-0.88]). EDA use was also associated with decreased prolonged mechanical ventilation, unplanned intubation, nonsteroidal anti-inflammatory drug use, acetaminophen use, postoperative length of stay, and total hospitalization costs and increased vasopressor use. One-to-three propensity score matching and instrumental variable analyses demonstrated equivalent results.

CONCLUSIONS

EDA use in oncologic MIE was associated with low in-hospital mortality as well as decreased respiratory complications, and anastomotic leakage, suggesting the potential advantage of EDA use in MIE.

Prediction of anastomotic leakage after left-sided colorectal cancer surgery: a pilot study utilizing quantitative near-infrared spectroscopy

BACKGROUND

Anastomotic leakage (AL) occurs with some frequency in all types of colorectal cancer surgery and is associated with increased morbidity, mortality and recurrence rates. Complications might be prevented by monitoring intra-operative bowel perfusion at the anastomotic site. A pilot study concerning the objective and quantitative measurement of tissue perfusion by monitoring regional tissue saturation of oxygen (rSO₂) was conducted, using the In Vivo Optical Spectroscopy (INVOS™) system (Medtronic, Minneapolis, MN, USA).

METHODS

This study evaluated the ability of the INVOS™ system to predict AL after left-sided colorectal cancer surgery. rSO₂ measurements of the oral side of the site of bowel anastomosis were taken before anastomosis in 73 patients. Clinical factors, including rSO₂, were analyzed to identify risk factors for AL.

RESULTS

Among 73 patients, 6 (8.2%) experienced AL. The rSO₂ values of the oral anastomotic site were significantly lower in AL patients than in non-AL patients. In the multivariate analysis, the rSO₂ value of the oral anastomotic site was an independent risk factor for AL.

CONCLUSION

Monitoring the rSO₂ at the anastomotic site enabled the prediction of AL. A prospective study to evaluate the efficacy of the INVOS™ system for monitoring intestinal rSO₂ is in progress.

Epidural analgesia is associated with earlier gastrointestinal transit after radical cystectomy but does not reduce the incidence of postoperative ileus: A retrospective cohort study

Objective:

To compare the effect of combined epidural thoracic analgesia and general anaesthesia (CEGA) in radical cystectomy (RC) with respect to the return of gastrointestinal passage, the incidence of paralytic postoperative ileus (POI) compared to general anaesthesia (GA) only.

Patients and methods:

We conducted a retrospective review using the electronic medical records of 236 patients who underwent RCs between July 2011 and September 2018 at the Medical Center – University of Freiburg.

Results:

A CEGA was administered to 202 patients, while 34 patients received only GA. The baseline characteristics of patients with and without CEGA showed no significant differences. CEGA will decrease the time required for return of gastrointestinal transit as measured by time to first defecation by about 13 hours. In the first 90 days after surgery, 82 (34.7%) patients had a POI. There was no significant difference between complications in the CEGA and GA groups.

Conclusion:

A CEGA accelerates the return of the gastrointestinal transit but does not reduce the incidence of postoperative ileus.

Level of evidence:

2b

Ultrasonography guided rectus sheath catheters versus epidural analgesia for open colorectal cancer surgery in a single centre

INTRODUCTION

Epidural anaesthesia (EA) has been the accepted standard for postoperative analgesia in open abdominal surgery. However, it is not without significant risk. This study aimed to audit the effect of EA and ultrasonography placed rectus sheath catheters (RSCs) on analgesia as well as the incidence of postoperative complications following open colorectal cancer surgery.

METHODS

A three-year retrospective case note review was undertaken of all patients undergoing open colorectal cancer surgery at the Royal Devon and Exeter Hospital NHS Foundation Trust who received either EA or RSC for postoperative analgesia under the care of the senior authors. A single surgeon and single anaesthetist were practitioners.

RESULTS

The case notes of 120 patients were reviewed retrospectively: 85 patients had EA and 24 RSC while 11 patients were excluded from the study. The EA group experienced a significantly higher incidence of hypotension (systolic blood pressure <130 mmHg) than the RSC group on the first postoperative day (p=0.0001). There was no significant difference in pain score or opiate sparing properties between the groups (p=0.92). There was no significant difference in postoperative respiratory tract infection, anastomotic leak or wound complications between the groups (p=0.2, p=1.0 and p=0.5 respectively). The RSC group had a higher incidence of ileus than the EA group (4/24 vs 2/85, p=0.026). However, the numbers were too small to draw a reliable conclusion.

CONCLUSIONS

The use of ultrasonography guided RSCs has demonstrated effective postoperative analgesia equivalent to EA with the potential benefits of a reduced incidence of hypotension. A prospective randomised trial is now underway to compare RSC and EA in open abdominal and pelvic surgery.

Ultrasonography guided rectus sheath catheters versus epidural analgesia for open colorectal cancer surgery in a single centre

INTRODUCTION

Epidural anaesthesia (EA) has been the accepted standard for postoperative analgesia in open abdominal surgery. However, it is not without significant risk. This study aimed to audit the effect of EA and ultrasonography placed rectus sheath catheters (RSCs) on analgesia as well as the incidence of postoperative complications following open colorectal cancer surgery.

METHODS

A three-year retrospective case note review was undertaken of all patients undergoing open colorectal cancer surgery at the Royal Devon and Exeter Hospital NHS Foundation Trust who received either EA or RSC for postoperative analgesia under the care of the senior authors. A single surgeon and single anaesthetist were practitioners.

RESULTS

The case notes of 120 patients were reviewed retrospectively: 85 patients had EA and 24 RSC while 11 patients were excluded from the study. The EA group experienced a significantly higher incidence of hypotension (systolic blood pressure <130 mmHg) than the RSC group on the first postoperative day (p=0.0001). There was no significant difference in pain score or opiate sparing properties between the groups (p=0.92). There was no significant difference in postoperative respiratory tract infection, anastomotic leak or wound complications between the groups (p=0.2, p=1.0 and p=0.5 respectively). The RSC group had a higher incidence of ileus than the EA group (4/24 vs 2/85, p=0.026). However, the numbers were too small to draw a reliable conclusion.

CONCLUSIONS

The use of ultrasonography guided RSCs has demonstrated effective postoperative analgesia equivalent to EA with the potential benefits of a reduced incidence of hypotension. A prospective randomised trial is now underway to compare RSC and EA in open abdominal and pelvic surgery.

A nationwide analysis of the use and outcomes of epidural analgesia in open colorectal surgery

INTRODUCTION

Epidural analgesia has demonstrated superiority over conventional analgesia in controlling pain following open colorectal resections. Controversy exists regarding cost-effectiveness and postoperative outcomes.

METHODS

The Nationwide Inpatient Sample (2002-2010) was retrospectively reviewed for elective open colorectal surgeries performed for benign and malignant conditions with or without the use of epidural analgesia. Multivariate regression analysis was used to compare outcomes between epidural and conventional analgesia.

RESULTS

A total 888,135 patients underwent open colorectal resections. Epidural analgesia was only used in 39,345 (4.4 %) cases. Epidurals were more likely to be used in teaching hospitals and rectal cancer cases. On multivariate analysis, in colonic cases, epidural analgesia lowered hospital charges by US$4,450 (p < 0.001) but was associated with longer length of stay by 0.16 day (p < 0.05) and a higher incidence of ileus (OR = 1.17; p < 0.01). In rectal cases, epidural analgesia was again associated with lower hospital charges by US$4,340 (p < 0.001) but had no effect on ileus and length of stay. The remaining outcomes such as mortality, respiratory failure, pneumonia, anastomotic leak, urinary tract infection, and retention were unaffected by the use of epidurals.

CONCLUSION

Epidural analgesia in open colorectal surgery is safe but does not add major clinical benefits over conventional analgesia. It appears however to lower hospital charges.

The effect of fluid overload in the presence of an epidural on the strength of colonic anastomoses

BACKGROUND

Despite the beneficial effects of epidurals in intra-abdominal surgery, the incidence of anastomotic leak remains controversial when used. Moreover, studies have also shown that fluid overload may be deleterious to anastomoses. The purpose of this paper is to evaluate the effects of varying intraoperative fluid protocols, in the presence of an epidural, on the burst pressure strength of colonic anastomoses.

METHODS

An epidural was installed in 18 rabbits, divided into three groups. Group 1 received 30 mL/kg/h Ringer's lactate, Group 2 received 100 mL/kg/h Ringer's lactate, and Group 3 received 30 mL/kg/h Pentaspan. Two colo-colonic anastomoses were performed per rabbit. On postoperative day 7 the anastomoses were resected and their burst pressures measured as a surrogate for anastomotic leak.

RESULTS

When comparing the average burst pressures of all three groups, there was a significant difference (P = 0.04). The anastomoses in the 100 mL/kg/h Ringer's lactate group were shown to be the weakest, with 64% of the anastomoses having burst under 120 mm Hg. The rabbits hydrated with Pentaspan had the highest strength, with no anastomoses bursting under 120 mm Hg. This translated into significant burst pressure differences (P = 0.02) between Group 2 and Group 3.

CONCLUSION

These results suggest that fluid overload with a crystalloid, in the presence of an epidural, may be deleterious to the healing of colonic anastomoses, creating a higher risk of anastomotic leak. Intraoperative resuscitation should thus focus on goal-directed euvolemia with appropriate amounts of colloids and/or crystalloids to prevent the risk of weakening anastomoses, especially in patients with epidurals.

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.

Intestinal effects of thoracic epidural anesthesia

PURPOSE OF REVIEW

Thoracic epidural anesthesia (TEA) is most frequently used after major surgery. However, despite ongoing research, the influence of TEA on the intestinal perioperative pathophysiology is not fully understood.

RECENT FINDINGS

According to recent results, the splanchnic sympathetic activity is reduced during TEA both in animal models and in clinical TEA. The splanchnic sympathetic activity during high TEA is still unknown. Intestinal perfusion effects of TEA are still unclear as the technique and extent of TEA, hemodynamic alteration and size of measurement result in--seemingly--conflicting reports. Postoperative ileus after laparotomy is ameliorated by TEA. Recent findings suggest beneficial effects also after major laparoscopic procedures. Finally, the impact of TEA on the intestinal pathophysiology in critical illness is an area of growing clinical and scientific interest, although this knowledge is just at its beginning.

SUMMARY

Further research concerning the use of TEA in major laparoscopic procedures and its potential to improve or endanger anastomotic healing is warranted. The experimental studies of TEA in critical illness should be expanded.

Reduction of oxygenation and blood flow in pedicled bowel segments in the rat and its consequences for anastomotic healing

PURPOSE

Experimental studies indicate that perioperative hypoperfusion impairs anastomotic healing. In bowel surgery, the part of bowel that will be anastomosed is often pedicled, leaving the blood supply dependent on the marginal artery only. Little is known about the blood supply in such a segment, and whether anastomotic strength is affected when flow would be reduced. This study describes oxygenation and blood flow in pedicled bowel segments in the rat and investigates whether early anastomotic strength changes with variations in blood flow.

METHODS

In rats, pedicled segments were created in ileum and colon by successive ligation of the feeding arteries. Oxygenation and blood flow were measured in the distal part of this segment by use of near-infrared spectroscopy with indocyanine green as an intravascular tracer. In a second experiment, a short pedicled colonic segment was created and, after flow measurements, an anastomosis was constructed. Wound strength and hydroxyproline content were analyzed 2 and 5 days after operation.

RESULTS

After creation of a pedicled segment, the concentration of oxygenated hemoglobin decreased significantly. Blood flow also significantly decreased to even less than 10% of baseline. A very large variation was observed between animals, in particular, after ligation of the first arteries. The strength of colonic anastomoses was not significantly correlated with the blood flow in the pedicled segment before anastomotic construction.

CONCLUSIONS

The creation of a pedicled bowel segment greatly reduces tissue oxygenation and blood flow to its distal part. Such impaired perioperative flow does not significantly affect early wound strength after anastomotic construction.

Epidural analgesia for pancreatoduodenectomy: a critical appraisal

INTRODUCTION

Epidural analgesia has emerged as a commonly applied method to improve pain management and reduce perioperative complications in major abdominal surgery. However, there is no detailed analysis of its efficacy for pancreatic operations. This study compares clinical and economic outcomes after epidural and intravenous analgesia for pancreatoduodenectomy.

MATERIAL AND METHODS

Data for 233 consecutive patients, who underwent pancreatoduodenectomy, were prospectively acquired and retrospectively reviewed at a single institution, pancreato-biliary specialty practice. From October 2001 to February 2007, all patients were offered thoracic epidural analgesia, and those who declined received intravenous analgesia. Perioperative pain management was dictated as an element of a standardized clinical pathway for pancreatic resections. Clinical and economic outcomes were analyzed and compared for epidural analgesia and intravenous analgesia groups.

RESULTS

One hundred eighty-five patients received epidural analgesia, and 48 received intravenous analgesia, with equivalent baseline patient demographics between the groups. Patients administered epidural analgesia had lower pain scores but significantly higher rates of major complications. Pancreatic fistulae and postoperative ileus occurred more frequently, and patients with epidural analgesia more often required discharge to rehabilitation facilities. A trend towards longer hospitalizations was observed among epidural analgesia patients, but total costs were statistically equivalent between the groups. Further analysis demonstrates that 31% of epidural infusions were aborted before anticipated (fourth postoperative day) because of hemodynamic compromise and/or inadequate analgesia. These select patients required more transfusions, aggressive fluid resuscitation, and subsequently suffered even higher rates of gastrointestinal and respiratory complications, all attributing to higher costs. Multivariate analysis demonstrates that preoperative hematocrit concentration less than 36%, elderly age (>75 years), and chronic pancreatitis predict failure of epidural infusions.

CONCLUSION

Thoracic epidural analgesia after pancreatic resections is associated with hemodynamic instability, which may compromise enteric anastomoses, gastrointestinal recovery, and respiratory function. These outcomes are exacerbated in poorly functioning epidurals and suggest that epidural analgesia may not be the optimal method for perioperative pain control when pancreatoduodenectomy is performed.

The effect of epidural analgesia on postoperative outcome after colorectal surgery

OBJECTIVE

The aim of this review was to determine the effects of epidural analgesia as it relates to outcome after colorectal surgery.

METHOD

We searched and reviewed studies that included colorectal surgery and epidural method of analgesia listed on the Pubmed, Medline, Embase and the Cochrane library database.

RESULTS

The majority of data demonstrate a superior effect of epidural analgesia on pain control after colorectal surgery. Well designed randomized controlled trials (RCT's) have also shown that epidural analgesia reduces the duration of ileus after colorectal surgery. Limited data suggest the additional benefit may be minimal after laparoscopic surgery or when epidural analgesia is used as part of a multimodal regime. Data does not convincingly show either a clear harmful or beneficial effect of epidural analgesia on rates of anastomotic leakage. Epidural analgesia may have beneficial effects on postoperative lung function, however due to low numbers, the effects on cardiovascular and thromboembolic complications are indeterminate. Length of hospital stay has not been shown to be shortened by sole use of an epidural and, although epidural analgesia may be apparently more costly, alternatives may incur higher indirect costs and decreased patient satisfaction.

CONCLUSION

Randomized controlled trials have shown a benefit for epidurals on postoperative pain relief, and ileus, and possibly respiratory complications. There is no proven benefit with regard to length of stay. There are a number of unresolved issues which further focussed RCT's may help clarify such as effects of epidural on complication rates after colorectal surgery.

Laser Doppler assessment of the influence of division at the root of the inferior mesenteric artery on anastomotic blood flow in rectosigmoid cancer surgery

AIMS

The aim of this study is to evaluate the influence of dividing the inferior mesenteric artery (IMA) and preserving the left colic artery (LCA) on rectosigmoid cancer surgery.

PATIENTS AND METHODS

Colonic blood flow at the proximal site of the anastomosis was measured by laser Doppler flowmetry in 96 patients with cancer of the rectum and sigmoid colon while clamping IMA or LCA. Results were analyzed with patient characteristics and postoperative complications.

RESULTS

Blood flow was significantly decreased by either IMA or LCA clamping, and its reduction rate was 38.5 +/- 1.8%, ranged from 0 to 82.8%, or 16.4 +/- 1.8%, ranged from 0 to 66.2%, respectively. For multivariate analyses, aging and male gender were predictive factors of high blood flow reduction by IMA clamping. The reduction rate was significantly correlated with aging in male patients, while no such correlation was observed in women. Aging correlation in men was more significant in ultralow anterior resection cases. Three elderly male patients received IMA high ligation among 19 patients who demonstrated more than 50% blood flow reduction by IMA clamping. Among these, two patients, those who underwent ultralow anterior resection, suffered severe anastomotic ischemia.

CONCLUSIONS

Colonic blood flow at the proximal site of the anastomosis was significantly decreased by either IMA or LCA clamping. Patients with high reduction by IMA clamping need intraoperative efforts to prevent anastomotic ischemia, particularly in elderly male patients who undergo ultralow anterior resection.

Does epidural anaesthesia and analgesia really improves surgical outcome after colorectal cancer surgery?

Lithuanian Cancer Register has registered 1443 new cases of colorectal cancer in 2004 and this value constantly increases about 200 cases per year. Colorectal cancer is on the third place among all cancer patients in our country. Colorectal cancer surgery is associated with a major surgical trauma. Majority of recent randomized clinical trials (RCT) has shown that combined general--epidural anaesthesia and postoperative epidural analgesia has demonstrated some beneficial effects and improved surgical outcome in various fields of surgery. However controversies still exist about epidural anaesthesia and analgesia effects on colorectal anastomosis and it's influence on patients' outcome.

Randomized clinical trial to evaluate the effects of perioperative supplemental oxygen administration on the colorectal anastomosis

Background

Perioperative supplemental oxygen therapy may have beneficial effects on wound healing following colorectal surgery. The aim of this study was to evaluate the effects of such therapy on colorectal anastomotic pH and partial pressure of carbon dioxide (Pco2) gap.

Methods

Forty-five patients undergoing anterior resection for rectal or sigmoid cancer were randomized to receive 30 or 80 per cent perioperative oxygen. Administration was commenced after induction of anaesthesia and maintained for 6 h after surgery. Intragastric and anastomotic tonometric catheters were placed in each patient and intramucosal pH (pHi) was measured immediately after operation, and 6 and 24 h later. Gastric and anastomotic pHi and Pco2 gap in each group were compared.

Results

There was a significantly lower anastomotic pHi and wider Pco2 gap for gastric readings in the 30 per cent O2 group, both 30 min (pHi, P = 0·006; Pco2 gap, P = 0·006) and 6 h (pHi, P = 0·024; Pco2 gap, P = 0·036) after surgery. There were no differences 24 h after surgery while breathing room air (pHi, P = 0·131; Pco2 gap P = 0·139). No difference was found between gastric and anastomotic readings at any time point in the 80 per cent O2 group.

Conclusion

Perioperative administration of 80 per cent O2 both during surgery and for 6 hours afterwards is associated with an improvement in relative anastomotic hypoperfusion as assessed by the measurement of pHi and Pco2 gap.

Effects of thoracic epidural anaesthesia on microvascular gastric mucosal oxygenation in physiological and compromised circulatory conditions in dogs

BACKGROUND

The effects of thoracic epidural anaesthesia (TEA) on gastric mucosal microvascular haemoglobin oxygenation (microHbO(2)) are unclear. At the splanchnic level, reduction of sympathetic tone may promote vasodilation and increase microHbO(2). However, these splanchnic effects are counteracted by systemic effects of TEA (e.g., decreased cardiac output (CO) and mean arterial pressure (MAP)), thus making the net effect on microHbO(2) difficult to predict. In this respect, effects of TEA on microHbO(2) may differ between physiological and compromised circulatory conditions, and additionally may depend on adequate fluid resuscitation. Furthermore, TEA may alter the relationship between regional microHbO(2) and systemic oxygen-transport (DO(2)).

METHODS

Chronically instrumented dogs (flow probes for CO measurement) were anaesthetized, their lungs ventilated and randomly received TEA with lidocaine (n=6) or epidural saline (controls, n=6). Animals were studied under physiological and compromised circulatory conditions (PEEP 10 cm H(2)O), both with and without fluid resuscitation. We measured gastric mucosal microHbO(2) by reflectance spectrophotometry, systemic DO(2), and systemic haemodynamics (CO, MAP).

RESULTS

Under physiological conditions, TEA preserved microHbO(2) (47 (3)% and 49 (5)%, mean (sem)) despite significantly decreasing DO(2) (11.3 (0.8) to 10.0 (0.7) ml kg(-1) min(-1)) and MAP (66 (2) to 59 (3) mm Hg). However, during compromised circulatory conditions, TEA aggravated the reduction in microHbO(2) (to 32 (1)%), DO(2) (to 6.7 (0.8) ml kg(-1) min(-1)) and MAP (to 52 (4) mm Hg), compared with controls. During TEA, fluid resuscitation completely restored these variables. TEA preserved the correlation between microHbO(2) and DO(2), compared with controls.

CONCLUSIONS

TEA maintains microHbO(2) under physiological conditions, but aggravates the reduction of microHbO(2) induced by cardiocirculatory depression, thereby preserving the relationship between gastric mucosal and systemic oxygenation.

Epidural analgesia in gastrointestinal surgery

BACKGROUND

The ideal perioperative analgesia should provide effective pain relief, avoid the detrimental effects of the stress response, be simple to administer without the need for intensive monitoring, and have a low risk of complications.

METHODS

This review defines the physiological effects of epidural analgesia and assesses whether the available evidence supports its preferential use in gastrointestinal surgery. All papers studied were identified from a Medline search or selected by cross-referencing.

RESULTS

Epidural analgesia is associated with a shorter duration of postoperative ileus, attenuation of the stress response, fewer pulmonary complications, and improved postoperative pain control and recovery. It does not reduce anastomotic leakage, intraoperative blood loss, transfusion requirement, risk of thromboembolism or cardiac morbidity, or hospital stay compared with that after conventional analgesia in unselected patients undergoing gastrointestinal surgery. Thoracic epidural analgesia reduces hospital costs and stay in patients at high risk of cardiac or pulmonary complications.

CONCLUSIONS

Epidural analgesia enhances recovery after gastrointestinal surgery. The results support the development of structured regimens of early postoperative feeding and mobilization to exploit the potential for thoracic epidural analgesia to reduce hospital stay after gastrointestinal surgery.

Thoracic epidural anesthesia improves the gastric microcirculation during experimental gastric tube formation

BACKGROUND

Gastric tube formation is a surgical technique to reestablish the continuity of the gastrointestinal tract after esophagectomy. Our aims were to study the microcirculatory consequences of experimental gastric tube formation and characterize the effects of thoracic epidural anesthesia (TEA) during this condition.

METHODS

The experiments were performed on mongrel dogs anesthetized with pentobarbital. The stomach was prepared for replacement according to the method of Akiyama, and TEA was induced with bupivacaine (1 mg/kg). Macrohemodynamics, intramucosal pH, and gastric motility changes were monitored, and intravital video-microscopy with orthogonal polarization spectral imaging technique was used to observe the gastric microcirculation.

RESULTS

The gastric pull-up induced a significant decrease in intramucosal pH. The functional capillary density of the mucosa or subserosa did not change; the red blood cell velocity in the capillaries of the upper part of the gastric tube was decreased in the mucosa, as well as on the serosal side. After epidural anesthesia the red blood cell velocity returned to the baseline, and the gastric and intestinal motility index was significantly increased.

CONCLUSIONS

TEA significantly improves the microcirculation of the distal portion of the gastric tube and increases the intestinal and gastric motility after gastric pull-up. The procedure is favorable and should be recommended during reconstructive esophageal surgery.

The role of epidural anesthesia and analgesia in surgical practice

OBJECTIVE

To review the potential and proven benefits and complications of epidural anesthesia/analgesia.

SUMMARY BACKGROUND DATA

Advances in analgesia/anesthesia have improved patient satisfaction and perioperative outcomes. Epidural anesthesia/analgesia is one of these advances that is gaining rapid acceptance due to a perceived reduction in morbidity and overall patient satisfaction.

METHODS

A MEDLINE search was conducted for all pertinent articles on epidural anesthesia/analgesia.

RESULTS

Retrospective, prospective, and meta-analysis studies have demonstrated an improvement in surgical outcome through beneficial effects on perioperative pulmonary function, blunting the surgical stress response and improved analgesia. In particular, significant reduction in perioperative cardiac morbidity ( approximately 30%), pulmonary infections ( approximately 40%), pulmonary embolism ( approximately 50%), ileus ( approximately 2 days), acute renal failure ( approximately 30%), and blood loss ( approximately 30%) were noted in our review of the literature. Potential complications related to epidural anesthesia/analgesia range from transient paresthesias (<10%) to potentially devastating epidural hematomas (0.0006%).

CONCLUSIONS

Epidural anesthesia/analgesia has been demonstrated to improve postoperative outcome and attenuate the physiologic response to surgery.

Repair of full-thickness bowel injury

OBJECTIVE

Colon surgery is more and more often performed in complex situations such as after trauma, under immunosuppression, or in the elderly. Even under optimal conditions, anastomosis fails in certain situations. The objective of this study was to demonstrate the normal phases of bowel healing and to review the local and systemic factors affecting healing with special attention to critical care variables such as major surgery, acute hemorrhage, and infections.

DATA SOURCE

MEDLINE cited and/or published articles.

DESIGN

Review analysis.

RESULTS

Colon healing is a structured cascade of different phases that can be affected by a multitude of local (infection, ischemia) and systemic (diabetes, malnutrition, anemia, hypothermia, trauma) factors. The normal phases of repair, the resulting bursting pressure as an experimental index of healing, and the available published data on local and systemic factors affecting healing are summarized.

CONCLUSION

Several local and systemic factors negatively affect bowel healing; there is still a small portion of patients who fail to heal, suggesting that intrinsic factors need to be analyzed.

Epidural analgesia and risk of anastomotic leakage

BACKGROUND AND OBJECTIVES

Based on case reports of early anastomotic leakage in patients receiving epidural analgesia with local anesthetic and data to document a stimulatory effect of epidural block on gastrointestinal motility, it has been suggested that continuous infusion of epidural local anesthetic may lead to an increased incidence of anastomotic leakage. Therefore, we examined the association between continuous epidural local anesthetic and anastomotic leakage by reviewing the literature.

METHODS

Review of controlled, randomized clinical trials aiming to investigate postoperative complications in which continuous postoperative epidural local anesthetic was administered in patients scheduled for colorectal surgery with an anastomosis. Data were obtained from a Medline search (1966-May 2000), previous review articles, references cited in original papers, and personal communication with investigators. Twelve trials including a total of 562 patients met the inclusion criteria.

RESULTS

Sixteen of 266 patients (6.0%, 95% confidence interval [CI]: 3.5% to 9.6%) receiving postoperative epidural local anesthetic or epidural local anesthetic-opioid mixtures developed anastomotic leakage, compared with 10 of 296 patients (3.4%, 95% CI: 1.6% to 6.1%) receiving epidural or systemic opioid-based analgesia (P >.05 between groups, Fisher's test). The risk of overlooking a significant difference (type II error) was approximately 67% (power: 33%). Studies including more than 1,037 patients in each group are needed to demonstrate an increased risk of anastomotic leakage from 3.4% to 6.0% with 80% power and 2alpha = 0.05. There was no significant difference (P >.05 between groups, Fisher's test) between subgroups of study design: Epidural local anesthetic-versus systemic or epidural opioid, or epidural local anesthetic-opioid mixtures versus systemic or epidural opioid.

CONCLUSIONS

So far, there is no statistically significant evidence from randomized trials to indicate epidural analgesia with local anesthetic to be associated with an increased risk of anastomotic breakdown. However, relatively few patients have been included in randomized trials, indicating a need for more studies to secure valid conclusions.

Lessons from laparoscopic surgery-a fresh look at post-operative management after major colorectal procedures

OBJECTIVE

Laparoscopy holds promise of exciting advances in colorectal surgery, yet the data we require to draw appropriate evidence-based conclusions on its apparent advantages are sadly lacking. In the meantime, our focus on improved recovery after major colorectal resections has changed the way we manage patients after open surgery.

METHODS

A literature review was undertaken to collect published data on laparoscopic colorectal surgery. In addition, data on newer developments in open colorectal surgery were collected.

RESULTS

Although there are many published data in laparoscopic colorectal surgery, very few are randomized and controlled. It is clear that, at least in the short to medium term, oncological outcomes are comparable to open surgery. There are data suggesting advantages, including less immune suppression, faster recovery with earlier feeding, less ileus, shorter length of stay and earlier return to normal activity.

CONCLUSION

Unfortunately, due to study design the data are largely not comparable with open surgery data, and open surgery itself has changed to some extent recently. We must encourage recruitment of patients into current ongoing randomized controlled trials of laparoscopic and open surgery and await the results.

The effects of intraoperative intravenous clonidine on gastric intramucosal PCO2

To investigate the effects of clonidine given as an anesthetic adjunct on splanchnic perfusion, we determined intramucosal gastric PCO2 using gastric tonometry in 60 patients scheduled for large intestine surgery. After induction of anesthesia, patients were randomly assigned to four groups. Patients in Group 1 received an IV infusion of sufentanil (0.2 microg x kg(-1) x h(-1)); patients in Group 2 received an IV infusion of clonidine (4 microg/kg in 20 min followed by 2 microg x kg(-1) x h(-1)); patients in Group 3 received an IV infusion of ketamine (0.5 mg/kg followed by 0.25 mg x kg(-1) x h(-1)); patients in Group 4 received an epidural infusion of bupivacaine (7 mL of 0.5% followed by 5 mL/h of 0.25%). Gastric intramucosal PCO2 was assessed immediately before skin incision and every hour during surgery using a nasogastric tube. A last measurement was taken after skin closure. An arterial sample was collected simultaneously to measure arterial PCO2. Oxygen consumption (VO2/min) was continuously recorded. Gastric intramucosal PCO2 significantly increased during surgery in all groups independent of the anesthetic technique considered (P < 0.01) and was not related to metabolic changes or blood pressure variations. This increase, however, remains in the physiologic range. In conclusion, our results demonstrate that clonidine given as an anesthetic adjutant at the dose used has no deleterious effect on splanchnic perfusion during colonic surgery.

IMPLICATIONS

IV clonidine given as an anesthetic adjunct at a dose of 4 microg/kg in 20 min, followed by 2 microg x kg(-1) x h(-1), has no deleterious effect on splanchnic perfusion during colonic surgery.