The use of neostigmine to treat postoperative ileus in orthopedic spinal patients

Targeting TRPV1 and TRPA1: A feasible strategy for natural herbal medicines to combat postoperative ileus

Under physiological or pathological conditions, transient receptor potential (TRP) channel vanilloid type 1 (TRPV1) and TRP ankyrin 1 (TRPA1) possess the ability to detect a vast array of stimuli and execute diverse functions. Interestingly, increasing works have reported that activation of TRPV1 and TRPA1 could also be beneficial for ameliorating postoperative ileus (POI). Increasing research has revealed that the gastrointestinal (GI) tract is rich in TRPV1/TRPA1, which can be stimulated by capsaicin, allicin and other compounds. This activation stimulates a variety of neurotransmitters, leading to increased intestinal motility and providing protective effects against GI injury. POI is the most common emergent complication following abdominal and pelvic surgery, and is characterized by postoperative bowel dysfunction, pain, and inflammatory responses. It is noteworthy that natural herbs are gradually gaining recognition as a potential therapeutic option for POI due to the lack of effective pharmacological interventions. Therefore, the focus of this paper is on the TRPV1/TRPA1 channel, and an analysis and summary of the processes and mechanism by which natural herbs activate TRPV1/TRPA1 to enhance GI motility and relieve pain are provided, which will lay the foundation for the development of natural herb treatments for this disease.

The impact of acetylcholinesterase inhibitors on ileus and gut motility following abdominal surgery: a clinical review

Postoperative ileus is a common complication in the days following colorectal surgery occurring in up to 50% of patients. When prolonged, this complication results in significant morbidity and mortality, doubling the total costs of hospital stay. Postoperative ileus (POI) results from the prolonged inflammatory phase that is mediated in part by the cholinergic anti-inflammatory pathway. Acetylcholinesterase inhibitors, such as neostigmine and pyridostigmine, delay the degradation of acetylcholine at the synaptic cleft. This increase in acetylcholine has been shown to increase gut motility. They have been effective in the treatment of acute colonic pseudo-obstruction, but there is limited evidence for the use of these medications for reducing the incidence of POI. This review was conducted to summarise the evidence of acetylcholinesterase inhibitors' effect on gut motility and discuss their potential use as part of an enhanced recovery protocols to prevent or treat POI.

Acute Colonic Pseudo-Obstruction (Ogilvie Syndrome) After Primary Spinal Fusion: An Analysis of Outcomes and Risk Factors from 2005 to 2014

BACKGROUND

Ogilvie syndrome (OS) is a rare but serious condition seen in the postoperative period. This was an epidemiologic study using data from the National Inpatient Sample from 2005 to 2014 to look at incidence, risk factors, and outcomes associated with OS after primary spine fusion.

METHODS

International Classification of Diseases, Ninth Revision codes were used to identify patients who underwent spine fusion surgery. Patients were separated into 2 cohorts based on the diagnosis of OS. Outcome measures and risk factors for cohorts were analyzed using multivariate logistic regression and compared.

RESULTS

Over the 10-year study period, 3,884,395 patients underwent primary spine fusion surgery. Among these, 0.04% developed OS during the index hospitalization. The greatest incidence seen in primary fusion involved the thoracic spine (0.15%). OS was more common after spine fusion for spine deformity (P < 0.001). Patients with OS were more likely to be men (P < 0.001), older (P < 0.0001), and have more comorbidities (P < 0.0001). Patients with OS were more likely to require postoperative blood transfusions (odds ratio [OR], 3.39; 95% confidence interval [CI], 2.51-4.59; P < 0.001) and sustain any complication (OR, 4.20; 95% CI, 3.17-5.57; P < 0.001). Patients with OS had a longer length of stay (15.7 vs. 3.9 days; P < 0.001) and increased average hospitalization cost ($63,037.03 vs. $26,792.19; P < 0.001). The development of OS was associated with fluid electrolyte disorder (OR, 4.06; 95% CI, 2.99-5.51; P < 0.001).

CONCLUSIONS

OS is a rare but serious complication of primary spine fusion surgery. Identifying the specific risk factors, symptoms, and potential complications related to OS is critical to aid in decreasing the significant morbidity associated with its development.

Comparing the Effect of Neostigmine and Metoclopramide on Gastric Residual Volume of Mechanically Ventilated Patients in Intensive Care Unit: A Double-Blind Randomized Clinical Trial

Introduction

The gastric residual volume (GRV) monitoring in patients with mechanical ventilation (MV) is a common and important challenge. The purpose of this study was to compare the effect of neostigmine and metoclopramide on GRV among MV patients in the intensive care unit (ICU).

Methods

In a double-blind randomized clinical trial, a total of 200 mechanically ventilated ICU patients with GRV > 120 ml (6 hours after the last gavage) were randomly assigned into two groups (A and B) with 100 patients in each group. Patients in groups A and B received intravenous infusion of neostigmine at a dose of 2.5 mg/100 ml normal saline and metoclopramide at a dose of 10 mg/100 ml normal saline, within 30 minutes, respectively. GRV was evaluated 5 times for each patient, once before the intervention and 4 times (at 3, 6, 9, and 12 hours) after the intervention. In addition, demographic characteristics including age and gender, as well as severity illness based on the sequential organ failure assessment score (SOFA), were initially recorded for all patients.

Results

After adjusting of demographic and clinical characteristics (age, gender, and SOFA score), the generalized estimating equation (GEE) model revealed that neostigmine treatment increased odds of GRV improvement compared to the metoclopramide group (OR = 2.45, 95% CI: 1.60-3.76, P < 0.001). However, there is a statistically significant time trend (within-subject differences or time effect) regardless of treatment groups (P < 0.001).

Conclusion

According to the results, although neostigmine treatment significantly improved GRV in more patients in less time, within 12 hours of treatment, all patients in both groups had complete recovery. Considering that there was no significant difference between the two groups in terms of side effects, it seems that both drugs are effective in improving the GRV of ICU patients.

Injury Profile among Elite Youth Male Football Players in a German Academy

Studies that report injuries in elite youth football players are scarce. So far, no such studies have been reported in Germany. The aim of this study is to descriptively and statistically report the incidence of injuries that resulted in time-loss ≥ 4 days in the TSG Hoffenheim football academy by 138 male players aged between 12 and 19 years during one season. A total of 109 injuries were sustained by 76 players: 6.9 injuries occurred per 1000 hours of matches (95% CI, 5.0-9.6) and 0.7 injuries per 1000 hours of training (95% CI, 0.5-0.9) with a ratio of 9.8. Some 66% of all injuries occurred during matches. Injuries involved the lower limb (81%), upper limb (9%), head & neck (5%) and trunk injuries (5%). 21 (19%) of all injuries were regarded as severe and resulted in time-loss > 28 days. U16-U19 teams sustained more injuries (74, 68%) than U12-U15 (35, 32%) (P= 0.032). The most frequent diagnosis was thigh strain (22%). Time-loss ranged from 4-339 days (SD: 40, Average: 23). Many injuries were a result of strain. Available injury prevention programs should be adhered to more strictly. Dedicated epidemiological studies are needed to optimize focused injury prevention programs.

PyRICo-Pilot: pyridostigmine to reduce the duration of postoperative ileus after colorectal surgery - a phase II study

AIM

Postoperative ileus (POI) is a major problem after colorectal surgery. Acetylcholinesterase inhibitors such as pyridostigmine increase gastrointestinal (GI) motility through a cholinergic anti-inflammatory pathway. The purpose of this phase II pilot study is to determine the safety of oral pyridostigmine after elective colorectal surgery.

METHOD

This is a Stage 2b safety study (IDEAL framework). All adult patients undergoing elective colorectal resection or formation or reversal of stoma at the Royal Adelaide Hospital between September 2020 and January 2021 were eligible. The primary outcomes were 30-day postoperative complications, reported adverse events and GI-2 - a validated composite outcome measure of recovery of GI function after surgery, defined as the interval from surgery until first passage of stool and tolerance of a solid intake for 24 h (in whole days) in the absence of vomiting.

RESULTS

Fifteen patients were included in the study. The median age was 58 (range 50-82) years and seven (47%) were men. Most participants had an American Society of Anesthesiologists grade ≥2 (53%) and the median body mass index was 27 (24-35) kg/m² . There were 13 postoperative complications [seven were Clavien-Dindo (CD) 1, five CD 2 and one CD 3]. None appeared directly related to pyridostigmine administration, and none of the patients had any overt symptoms of excessive parasympathetic activity. Median GI-2 was 2 (1-4) days.

CONCLUSION

Oral pyridostigmine appears to be safe to use after elective colorectal surgery in a select group of patients. However, considering this is a pilot study with a small sample size, larger controlled studies are needed to confirm this finding and establish efficacy for prevention of POI.

Incidence and Risk Factors of Gastrointestinal and Hepatobiliary Complications after Spinal Fusion Surgery: a Retrospective Cohort Study

BACKGROUND

Spinal surgery holds a higher chance of unpredicted postoperative medical complications among orthopedic surgeries. Several studies have analyzed the risk factors for diverse postoperative medical complications, but the majority investigated incidences of each complication qualitatively. Among gastrointestinal complications, reports regarding postoperative ileus were relatively frequent. However, risk factors or incidences of hepatobiliary complications have yet to be investigated. The purpose of this study was to examine the incidence of gastrointestinal complications after spinal surgery, quantitatively analyze the risk factors of frequent complications, and to determine cues requiring early approaches.

METHODS

In total, 234 consecutive patients who underwent spinal fusion surgery performed by one senior doctor at our institute in one-year period were retrospectively enrolled for analyses. The primary outcomes were presence of paralytic ileus, elevated serum alanine transaminase (ALT) and aspartate transaminase (AST) levels, and elevated total bilirubin levels. Univariate logistic regression analyses of all variables were performed. In turn, significant results were reanalyzed by multivariate logistic regression. The variables used were adjusted with age and gender.

RESULTS

Gastrointestinal complications were observed in 15.8% of patients. Upon the risk factors of postoperative ileus, duration of anesthesia (odds ratio [OR], 1.373; P = 0.015), number of fused segments (OR, 1.202; P = 0.047), and hepatobiliary diseases (OR, 2.976; P = 0.029) were significantly different. For elevated liver enzymes, men (OR, 2.717; P = 0.003), number of fused segments (OR, 1.234; P = 0.033), and underlying hepatobiliary (OR, 2.704; P = 0.031) and rheumatoid diseases (OR, 5.021; P = 0.012) had significantly different results. Lastly, risk factors for total bilirubin elevation were: duration of anesthesia (OR, 1.431; P = 0.008), number of fused segments (OR, 1.359; P = 0.001), underlying hepatobiliary diseases (OR, 3.426; P = 0.014), and thoracolumbar junction involving fusions (OR, 4.134; P = 0.002) compared to lumbar spine limited fusions.

CONCLUSION

Patients on postoperative care after spinal surgery should receive direct attention as soon as possible after manifesting abdominal symptoms. Laboratory and radiologic results must be carefully reviewed, and early consultation to gastroenterologists or general surgeons is recommended to avoid preventable complications.

Acute Colonic Pseudo-Obstruction After Posterior Spinal Fusion: A Case Report and Literature Review

BACKGROUND

Acute colonic pseudo-obstruction (ACPO) or Ogilvie's syndrome occurs in 0.22%-7% of patients undergoing surgery, with a mortality of up to 46%. ACPO increased median hospital days versus control in spinal surgery (14 vs. 6 days; P < 0.001). If defined as postoperative ileus, the incidence was 7%-13.4%. Postoperative ileus is associated with 2.9 additional hospital days and an $80,000 increase in cost per patient. We present a case of ACPO in an adult patient undergoing spinal fusion for correction of scoliosis and review the available literature to outline clinical characteristics and surgical outcomes.

CASE DESCRIPTION

The patient was a 31-year-old woman with untreated advanced scoliosis with no history of neurologic issues. T2-L3 spinal instrumentation and fusion was completed. Plain abdominal radiography showed of dilated cecum 11 cm and the department of general surgery was consulted. Neostigmine administration was planned after conservative treatment failure after transfer to the intensive care unit. The patient was discharged home with no recurrence >60 days. Thirty cases were found in our literature review using PubMed and Embase databases and summarized.

CONCLUSIONS

Of 30 cases reviewed, only 3 cases of ACPO were specific to patients undergoing spinal fusion for scoliosis. According to the literature, 20% of patients had resolution with conservative treatment, 40% with neostigmine, and 30% with surgical intervention. Other noninvasive treatments may have similar efficacy in preventing complications leading to surgical invention. Sixty clinical trials and 9 systematic reviews were summarized with an updated management algorithm.

Neuromuscular blockade reversal with sugammadex versus pyridostigmine/glycopyrrolate in laparoscopic cholecystectomy: a randomized trial of effects on postoperative gastrointestinal motility

Background

Acetylcholinesterase inhibitors (e.g., pyridostigmine bromide) are used for neuromuscular blockade (NMB) reversal in patients undergoing surgery under general anesthesia (GA). Concurrent use of anticholinergic agents (e.g., glycopyrrolate) decreases cholinergic side effects but can impede bowel movements. Sugammadex has no cholinergic effects; its use modifies recovery of gastrointestinal (GI) motility following laparoscopic cholecystectomy compared to pyridostigmine/glycopyrrolate. This study evaluated the contribution of sugammadex to the recovery of GI motility compared with pyridostigmine and glycopyrrolate.

Methods

We conducted a prospective study of patients who underwent laparoscopic cholecystectomy. Patients were randomly allocated to the experimental group (sugammadex, Group S) or control group (pyridostigmine-glycopyrrolate, Group P). After anesthesia (propofol and rocuronium, and 2% sevoflurane), recovery was induced by injection of sugammadex or a pyridostigmine-glycopyrrolate mixture. As a primary outcome, patients recorded the time of their first passage of flatus (‘gas-out time’) and defecation. The secondary outcome was stool types.

Results

One-hundred and two patients participated (Group S [n = 49], Group P [n = 53]). Mean time from injection of NMB reversal agents to gas-out time was 15.03 (6.36–20.25) h in Group S and 20.85 (16.34–25.86) h in Group P (P = 0.001). Inter-group differences were significant. Time until the first defecation as well as types of stools was not significantly different.

Conclusions

Sugammadex after laparoscopic cholecystectomy under GA resulted in an earlier first postoperative passage of flatus compared with the use of a mixture of pyridostigmine and glycopyrrolate. These findings suggest that the use of sugammadex has positive effects on the recovery of GI motility.

Mechanism of Electroacupuncture on Postoperative Ileus Induced by Surgical Stress in Rats

Objectives: Acupuncture has been used for treating gastrointestinal (GI) disorders such as postoperative nausea and vomiting. Electroacupuncture (EA) accelerates GI transit following surgery and ameliorates postoperative ileus (POI) to restore colonic transit (CT); however, the mechanisms of this EA-induced restoration remain unclear. The aims of this study were to show CT following surgery and the effects of EA at ST 36 on POI induced by surgical stress (SS) in 45 conscious, male Sprague-Dawley rats. Materials and Methods: An operation was performed in each rat, setting a cannula into the cecum to connect the proximal colon to inject markers. On the day after surgery, 20 metal radiopaque markers were administered to the proximal colon of each rat. These markers were visible throughout the GI tract on soft X-ray immediately after administration and up to 240 minutes afterward. The rats were divided into 5 groups with 9 rats in each group: (1) SS; (2) 5 days post surgery (POST-5D); (3) SS + phentolamine; (4) EA alone; and (5) EA + atropine. The EA was performed at ST 36 for 20 minutes at a frequency of 10 Hz and agents were administered in the appropriate groups before markers were administered and measurements were taken. Measurements were performed the day after surgery except in the POST 5-D group. CT was calculated by the geometric center on the images showing the CT for each rat. Results: CT after surgery was delayed significantly and phentolamine accelerated CT. EA restored CT following surgery and atropine abolished the effect of EA on CT. Conclusions: The current study demonstrated that surgery induced a delay in CT through the sympathetic pathway via α-adrenoreceptors; CT was restored by EA. These results suggest that EA can be used to treat POI through mediation of the autonomic nervous system.

Application of Pyridostigmine in Pediatric Gastrointestinal Motility Disorders: A Case Series

BACKGROUND

Gastrointestinal (GI) motility disorders are common in children. Treatment is challenging with limited medical and surgical options. Pyridostigmine, an acetyl cholinesterase inhibitor, increases acetylcholine at the neuromuscular junction promoting intestinal contractions. Little is known about the role and dosing of pyridostigmine in pediatric GI motility disorders.

METHODS

We present a case series of children with GI dysmotility managed with oral pyridostigmine. Patients' diagnoses include chronic intestinal pseudo-obstruction, gastroparesis with delayed small bowel transit, chronic constipation with failure to thrive, and prolonged ileus after pelvic surgery with chronic opioid use.

RESULTS

Pyridostigmine was effective and safe in all cases. Pyridostigmine decreased abdominal distention, increased bowel movement frequency, and improved enteral feeding tolerance. Effective dosing ranged between 0.25-2.0 mg/kg/day. One patient experienced cramping abdominal pain while on pyridostigmine, but pain resolved after medication was discontinued.

CONCLUSION

We found oral pyridostigmine to be helpful in children with different GI motility problems. Pyridostigmine should be considered in such patients when other treatment interventions have not been beneficial.

Postoperative complications of spine surgery

A variety of surgical approaches are available for the treatment of spine diseases. Complications can arise intraoperatively, in the immediate postoperative period, or in a delayed fashion. These complications may lead to severe or even permanent morbidity if left unrecognized and untreated [1-4]. Here we review a range of complications in the early postoperative period from more benign complications such as postoperative nausea and vomiting (PONV) to more feared complications leading to permanent loss of neurological function or death [5]. Perioperative pain management is covered in a separate review (Chapter 8).

A Double-Blind Randomized Clinical Trial Comparing the Effect of Neostigmine and Metoclopramide on Gastric Residual Volume of Mechanically Ventilated ICU Patients

BACKGROUND

In critically ill patients, enteral feeding through the nasogastric tube is the method of choice for nutritional support. Gastrointestinal feeding intolerance and disturbed gastric emptying are common challenges in these patients. The aim of this study was to compare the effect of Neostigmine and Metoclopramide on gastric residual volume (GRV) in mechanically ventilated ICU patients.

METHODS

In a double blind, randomized clinical trial, a total of 60 mechanically ventilated ICU patients with GRV >120 mL (3 hours after the last gavage), were randomly assigned into two groups A and B. At baseline and 6 hours later, patients in group A and B received intravenous infusion of neostigmine in a dose of 2.5 mg and metoclopramide in a dose of 10 mg in 100 ml of normal saline, within 30 minutes. Patients' gastric residual volumes were evaluated before the beginning of the intervention, and 3, 6, 9 and 12 hours after the intervention.

RESULTS

After adjusting of other variables (Sex, BMI and ICU stay period) generalized estimating equation (GEE) model revealed that neostigmine treatment increased odds of GRV improvement compare to metoclopramide group (Estimate 1.291, OR= 0.3.64, 95% CI 1.07-12.34). However there is a statistically significant time trend (within-subject differences or time effect) regardless of treatment groups (P<0.001). The median time from intervention to GRV improvement was 6 hours (95% CI 3.75-8.25) and 9 hours (95% CI 7.38-10.17) in neostigmine and metoclopramide groups, respectively. This difference was statistically significant (P<0.05).

CONCLUSION

It seems that neostigmine is more effective than metoclopramide in reducing GRV and improving gastric emptying in mechanically ventilated ICU patients without significant complication and this protocol may be effective on the tolerance of enteral feeding in ICU patients. Further well-designed randomized clinical trials are needed.

Paralytic Ileus and Prophylactic Gastrointestinal Motility Medication after Spinal Operation

PURPOSE

To investigate the prevalence of paralytic ileus after spinal operation in the supine or prone operative position and to determine the efficacy of prophylactic gastrointestinal motility medications in preventing symptomatic paralytic ileus after a spinal operation.

MATERIALS AND METHODS

All patients received spinal surgery in the supine or prone operative position. The study period was divided into two phases: first, to analyze the prevalence of radiographic and symptomatic paralytic ileus after a spinal operation, and second, to determine the therapeutic effects of prophylactic gastrointestinal motility medications (postoperative intravenous injection of scopolamine butylbromide and metoclopramide hydrochloride) on symptomatic paralytic ileus after a spinal operation.

RESULTS

Basic demographic data were not different. In the first phase of this study, 27 patients (32.9%) with radiographic paralytic ileus and 11 patients (13.4%) with symptomatic paralytic ileus were observed. Radiographic paralytic ileus was more often noted in patients who underwent an operation in the prone position (p=0.044); whereas the occurrence of symptomatic paralytic ileus was not different between the supine and prone positioned patients (p=0.385). In the second phase, prophylactic medications were shown to be ineffective in preventing symptomatic paralytic ileus after spinal surgery [symptomatic paralytic ileus was observed in 11.1% (4/36) with prophylactic medication and 16.7% (5/30) with a placebo, p=0.513].

CONCLUSION

Spinal surgery in the prone position was shown to increase the likelihood of radiographic paralytic ileus occurrence, but not symptomatic paralytic ileus. Unfortunately, the prophylactic medications to prevent symptomatic paralytic ileus after spine surgery were shown to be ineffective.

Prevention of Paralytic Ileus Utilizing Alvimopan Following Spine Surgery

Postoperative ileus affects a substantial proportion of patients undergoing elective spine surgery, especially in cases of spinal deformity correction and where an anterior lumbar approach is utilized. Though the first line of treatment for postoperative ileus is conservative management, recent advances in pharmacology have yielded promising options for both treatment and prevention. We report a case of a patient who underwent a two-stage posterior spinal fusion. The patient suffered with a severe, prolonged ileus after her initial surgery. To prevent ileus following her second spinal surgery, alvimopan (a µ-opioid receptor antagonist) was administered and she had a rapid return of bowel function with no signs of ileus. Alvimopan, has been shown to reduce the rate of ileus in colorectal surgery patients, and may be useful for preventing ileus in high-risk orthopedic and spine surgery patients, although prospective studies will be needed to test this hypothesis.

Paralytic ileus in the orthopaedic patient

Paralytic ileus is marked by the cessation of bowel motility. This condition is a major clinical concern that may lead to severe patient morbidity in orthopaedic surgery and trauma patients. Ileus most commonly occurs following spinal surgery, traumatic injury, or lower extremity joint reconstruction, but it may also occur following minor orthopaedic procedures. Possible consequences of ileus include abdominal pain, malnutrition, prolonged hospital stay, hospital readmission, bowel perforation, and death. Therapies used in the treatment of ileus include minimization of opioids, early patient mobilization, pharmacologic intervention, and multidisciplinary care. Orthopaedic surgeons should be aware of the clinical signs and symptoms of paralytic ileus and should understand treatment principles of this relatively common adverse event.

Postoperative ileus: Recent developments in pathophysiology and management

BACKGROUND & AIMS

Postoperative ileus (POI) is a frequent occurrence after abdominal and other types of surgery, and is associated with significant morbidity and costs to health care providers. The aims of this narrative review were to provide an update of classification systems, preventive techniques, pathophysiological mechanisms, and treatment options for established POI.

METHODS

The Web of Science, MEDLINE, PubMed and Google Scholar databases were searched using the key phrases 'ileus', 'postoperative ileus' and 'definition', for relevant studies published in English from January 1997 to August 2014.

RESULTS

POI is still a problematic and frequent complication of surgery. Fluid overload, exogenous opioids, neurohormonal dysfunction, and gastrointestinal stretch and inflammation are key mechanisms in the pathophysiology of POI. Evidence is supportive of thoracic epidural analgesia, avoidance of salt and water overload, alvimopan and gum chewing as measures for the prevention of POI, and should be incorporated into perioperative care protocols. Minimal access surgery and avoidance of nasogastric tubes may also help. Novel strategies are emerging, but further studies are required for the treatment of prolonged POI, where evidence is still lacking.

CONCLUSIONS

Although POI is often inevitable, methods to reduce its duration and facilitate recovery of postoperative gastrointestinal function are evolving rapidly. Utilisation of standardised diagnostic classification systems will help improve applicability of future studies.

Postoperative ileus: mechanisms and future directions for research

Postoperative ileus (POI) is an abnormal pattern of gastrointestinal motility characterized by nausea, vomiting, abdominal distension and/or delayed passage of flatus or stool, which may occur following surgery. Postoperative ileus slows recovery, increases the risk of developing postoperative complications and confers a significant financial load on healthcare institutions. The aim of the present review is to provide a succinct overview of the clinical features and pathophysiological mechanisms of POI, with final comment on selected directions for future research.Terminology used when describing POI is inconsistent, with little differentiation made between the obligatory period of gut dysfunction seen after surgery ('normal POI') and the more clinically and pathologically significant entity of a 'prolonged POI'. Both normal and prolonged POI represent a fundamentally similar pathophysiological phenomenon. The aetiology of POI is postulated to be multifactorial, with principal mediators being inflammatory cell activation, autonomic dysfunction (both primarily and as part of the surgical stress response), agonism at gut opioid receptors, modulation of gastrointestinal hormone activity and electrolyte derangements. A final common pathway for these effectors is impaired contractility and motility and gut wall oedema. There are many potential directions for future research. In particular, there remains scope to accurately characterize the gastrointestinal dysfunction that underscores an ileus, development of an accurate risk stratification tool will facilitate early implementation of preventive measures and clinical appraisal of novel therapeutic strategies that target individual pathways in the pathogenesis of ileus warrant further investigation.

Defining postoperative ileus: results of a systematic review and global survey

BACKGROUND

There is a lack of an internationally accepted standardised clinical definition for postoperative ileus (POI). This has made it difficult to estimate incidence and identify risk factors and has compromised external validity of clinical trials.

AIM

To clarify terminology of POI and propose concise, clinically quantifiable definitions.

METHODS

A systematic review extracted definitions from randomised trials published between 1996 and 2011 investigating POI after abdominal surgery. This was followed by a global survey seeking opinions of those who have published in the field.

RESULTS

Definitions were extracted from 52 identified trials. Responses were received in the survey from 45 of 118 corresponding authors. Data were amalgamated to synthesise the following definitions: postoperative ileus (POI) "interval from surgery until passage of flatus/stool AND tolerance of an oral diet"; prolonged POI "two or more of nausea/vomiting, inability to tolerate oral diet over 24 h, absence of flatus over 24 h, distension, radiologic confirmation occurring on or after day 4 postoperatively without prior resolution of POI"; recurrent POI "two or more of nausea/vomiting, inability to tolerate oral diet over 24 h, absence of flatus over 24 h, distension, radiologic confirmation, occurring after apparent resolution of POI". Concordance of the latter two definitions with survey responses were ≥75 %.

CONCLUSION

We have proposed standardised endpoints for use in future studies to facilitate objective comparison of competing interventions.

Acute Colonic Pseudo-Obstruction (Ogilvie's Syndrome)

Acute colonic pseudo-obstruction is a complication that occurs in hospitalized patients with serious underlying medical or surgical conditions; it is characterized by acute colonic dilatation in the absence of mechanical obstruction. The pathogenesis is incompletely elucidated, but changes in autonomic nervous system function are likely to contribute, as are metabolic and pharmacologic factors. Early diagnosis and appropriate intervention are critical in this disorder, which carries with it considerable morbidity and mortality. Treatment options, consecutively applied, include conservative measures, pharmacologic treatment with neostigmine, and endoscopic decompression. Surgical decompression or resection is necessary in case of refractoriness or perforation, respectively.

A national epidemiological study of Myasthenia Gravis in Australia

BACKGROUND AND PURPOSE

Existing epidemiological studies of Myasthenia Gravis have generally examined small populations. Few national studies have been conducted, and published incidence and prevalence rates vary widely. We report one of the largest national studies of Myasthenia Gravis, and the first incidence and prevalence rates for Australia.

METHODS

Prescriptions for Pyridostigmine Bromide in 2009 were utilized from a national prescribing database to estimate incidence and the prevalence of symptomatic and treated disease. Crude rates were age-standardized to the WHO world population. We compared standardized rates to recent national studies from Norway and Taiwan.

RESULTS

In 2009, there were 2574 prevalent cases of symptomatic and treated Myasthenia Gravis, corresponding to an annual crude prevalence rate of 117.1 per 1 million residents. There were 545 incident cases, yielding a crude incidence rate of 24.9 per 1 million residents. The crude incidence in women and men was estimated to be 27.9 and 21.9 per 1 million, respectively. Prevalence and incidence rates were higher in women than men between the ages of 15 and 64 years, and were higher in men than women in those older than 65 years. Rates peaked between the ages of 74 and 84 years, declining thereafter. Standardized incidence was higher in Australia than Norway, but similar to Taiwan (P-values = 0.007 and 1.00, respectively).

CONCLUSIONS

This first Australian epidemiological study of symptomatic Myasthenia Gravis is one of the largest population-based studies ever reported and supports higher incidence rates for Myasthenia Gravis. Myasthenia Gravis disproportionately affected younger females and older males.

Intravenous neostigmine for postoperative acute colonic pseudo-obstruction

OBJECTIVE

To review the literature on the safety and effectiveness of neostigmine for the treatment of postoperative acute colonic pseudo-obstruction.

DATA SOURCES

The MEDLINE/PubMed, EMBASE, and Cochrane databases from November 1969 to November 2011 were queried for articles published in English, using the search terms neostigmine, acute colonic pseudo-obstruction, postoperative, surgery, and Ogilvie syndrome.

STUDY SELECTION AND DATA EXTRACTION

All relevant original studies, meta-analyses, systematic reviews, guidelines, and review articles were assessed for inclusion. References from pertinent articles were examined for additional content not found during the initial search.

DATA SYNTHESIS

Neostigmine may provide an effective treatment option for postoperative acute colonic pseudo-obstruction (ACPO) after conservative treatment measures have failed. One randomized controlled trial, 8 prospective and 3 retrospective observational studies, and 9 case reports evaluated neostigmine for ACPO. Included studies were limited by small sample sizes and heterogeneous populations not focused on postoperative patients, use of adjuvant agents, and lack of a consistent neostigmine regimen.

CONCLUSIONS

Neostigmine may be a safe and effective treatment option for postoperative ACPO; however, current data do not support its use as a first-line intervention. Prospective and retrospective studies have demonstrated improvement in clinical symptoms, reduction in time to resolution, and reduction of recurrence for patients who failed conservative management. Prospective clinical trial data that evaluate early neostigmine versus conservative management are critically needed to determine neostigmine's role as a first-line therapy for ACPO.

Complications and outcomes after spinal deformity surgery in the elderly: review of the existing literature and future directions

Object

The elderly population (age > 60 years) is the fastest-growing age group in the US. Spinal deformity is a major problem affecting the elderly and, therefore, the demand for surgery for spinal deformity is becoming increasingly prevalent in elderly patients. Much of the literature on surgery for adult deformity focuses on patients who are younger than 60 years, and therefore there is limited information about the complications and outcomes of surgery in the elderly population.

In this study, the authors undertook a review of the literature on spinal deformity surgery in patients older than 60 years. The authors discuss their analysis with a focus on outcomes, complications, discrepancies between individual studies, and strategies for complication avoidance.

Methods

A systematic review of the MEDLINE and PubMed databases was performed to identify articles published from 1950 to the present using the following key words: “adult scoliosis surgery” and “adult spine deformity surgery.” Exclusion criteria included patient age younger than 60 years. Data on major Oswestry Disability Index (ODI) scores, visual analog scale (VAS) scores, patient-reported outcomes, and complications were recorded.

Results

Twenty-two articles were obtained and are included in this review. The mean age was 74.2 years, and the mean follow-up period was 3 years. The mean preoperative ODI was 48.6, and the mean postoperative reduction in ODI was 24.1. The mean preoperative VAS score was 7.7 with a mean postoperative decrease of 5.2. There were 311 reported complications for 815 patients (38%) and 5 deaths for 659 patients (< 1%).

Conclusions

Elderly patient outcomes were inconsistent in the published studies. Overall, most elderly patients obtained favorable outcomes with low operative mortality following surgery for adult spinal deformity.

Critical illness, gastrointestinal complications, and medication therapy during enteral feeding in critically ill adult patients

Critically ill patients who are subjected to high stress or with severe injury can rapidly break down their body protein and energy stores. Unless adequate nutrition is provided, malnutrition and protein wasting may occur, which can negatively affect patient outcome. Enteral nutrition (EN) is the mainstay of nutrition support therapy in patients with a functional gastrointestinal (GI) tract who cannot take adequate oral nutrition. EN in critically ill patients provides the benefits of maintaining gut functionality, integrity, and immunity as well as decreasing infectious complications. However, the ability to provide timely and adequate EN to critically ill patients is often hindered by GI motility disorders and complications associated with EN. This paper reviews the GI complications and intolerances associated with EN in critically ill patients and provides recommendations for their prevention and treatment. It also addresses the role of commonly used medications in the intensive care unit and their impact on GI motility and EN delivery.

Continuous intravenous lidocaine in the treatment of paralytic ileus due to severe spinal cord injury

Paralytic ileus is a major concern in the acute phase of spinal cord injury. Classical treatment with neostigmine is often ineffective. Continuous intravenous (i.v.) lidocaine infusion has been previously proposed intra and post-operatively in order to decrease the duration of post-operative ileus after abdominal surgery. We report the cases of seven patients suffering from complete paralytic spinal cord injury-related ileus with colectasy resistant to neostigmine, who were treated by i.v. lidocaine infusion.

Effect of bisacodyl on postoperative bowel motility in elective colorectal surgery: a prospective, randomized trial

BACKGROUND

Postoperative ileus is a common condition after abdominal surgery. Many prokinetic drugs have been evaluated including osmotic laxatives. The data on colon-stimulating laxatives are scarce. This prospective, randomized, double-blind trial investigates the effect of the colon-stimulating laxative bisacodyl on postoperative ileus in elective colorectal resections.

MATERIALS AND METHODS

Between November 2004 and February 2007, 200 consecutive patients were randomly assigned to receive either bisacodyl or placebo. Primary endpoint was time to gastrointestinal recovery (mean time to first flatus passed, first defecation, and first solid food tolerated; GI-3). Secondary endpoints were incidence and duration of nasogastric tube reinsertion, incidence of vomiting, length of hospital stay, and visual analogue scores for pain, cramps, and nausea.

RESULTS

One hundred sixty-nine patients were analyzed, and 31 patients discontinued the study. Groups were comparable in baseline demographics. Time to GI-3 was significantly shorter in the bisacodyl group (3.0 versus 3.7 days, P = 0.007). Of the single parameters defining GI-3, there was a 1-day difference in time to defecation in favor to the bisacodyl group (3.0 versus 4.0 days, P = 0.001), whereas no significant difference in time to first flatus or tolerance of solid food was seen. No significant difference in the secondary endpoints was seen. Morbidity and mortality did not differ between groups.

CONCLUSION

Bisacodyl accelerated gastrointestinal recovery and might be considered as part of multimodal recovery programs after colorectal surgery.

A novel method for the evaluation of intestinal transit and contractility in mice using fluorescence imaging and spatiotemporal motility mapping

This study introduces a novel, simplified method for the evaluation of murine intestinal transit and contractility using fluorescence and video imaging. Intestinal transit was measured by evaluating the intestinal distribution of non-absorbable fluorescein-labelled dextran (70 kDa, FD70) along the gastrointestinal (GI) tract. After excision of the GI tract, two full-field images--one in normal illumination mode and another in fluorescent mode--were taken with a charge coupled device (CCD) camera and subsequently matched for calculation of fluorescence distribution along the GI tract. Immediately after, intestinal contractility was evaluated in different regions of the intact intestine by spatiotemporal motility mapping (i.e. video imaging). In control mice, the small intestine showed vigorous oscillatory contractions and FD70 was primarily distributed within the terminal ileum/caecum at 90 min postgavage. As validation step, the effect of intestinal manipulation (IM, surgical procedure) and two pharmacological agents--known to alter GI motility--was tested. At 24 h postoperatively, spontaneous contractile activity of the small intestine was nearly abolished in IM mice, leaving the small intestine distended and resulting in a significantly delayed intestinal transit. In accordance, spontaneous mechanical activity of circular muscle strips in standard organ baths was significantly reduced in IM mice compared to control mice. Administration of atropine (1-3 mg kg(-1), i.p.) suppressed spontaneous contractile activity along the entire intestinal tract and induced a dose-related delay in intestinal transit. In contrast, metoclopramide (3-10 mg kg(-1), i.p.) markedly increased contractile activity--however only in the upper GI tract--and accelerated intestinal transit in a dose-dependent manner.

Synergy between 5-HT4 receptor activation and acetylcholinesterase inhibition in human colon and rat forestomach

5-Hydroxytryptamine (5-HT4) receptor agonists increase gastrointestinal (GI) motility by enhancing enteric acetylcholine release which is then metabolized by acetylcholinesterase (AChE) to inactive metabolites. As both AChE inhibitors and, more usually, 5-HT4 receptor agonists are used to increase GI motility, an understanding of how these two different types of drugs might interact becomes of great importance. Our aim was to investigate the hypothesis that the effect of AChE inhibition will synergise with the ability of 5-HT4 receptor agonism to increase cholinergic activity, leading to an effect greater than that evoked by each action alone. We tested the activity of the 5-HT4 receptor agonist, prucalopride (10 nmol L(-1)-30 micromol L(-1)) and an AChE inhibitor, neostigmine (1 nmol L(-1)-10 micromol L(-1)) on cholinergically mediated contractions elicited by electrical field stimulation of human isolated colon circular muscle and rat isolated forestomach longitudinal strips. The experiments with human colon were performed in the presence of an inhibitor of nitric oxide synthase (N(omega)-nitro-l-arginine methyl ester, 300 micromol L(-1)). Prucalopride and neostigmine both enhanced cholinergic contractions in both tissues. The effect of prucalopride was inhibited in both tissues by SB-204070, a 5-HT4 receptor antagonist. In the presence of a minimum effective concentration of neostigmine (30 nmol L(-1)) and a submaximum concentration of prucalopride (3 micromol L(-1)) the enhancement of contractions was greater than either compound alone in both tissues. These data demonstrate that the combination of prucalopride and neostigmine potentiate cholinergic contractions more than their arithmetic sum of their individual values. The results suggest that a synergy between 5-HT4 receptor agonism and AChE inhibition could be established pharmacologically which could be utilized as a novel prokinetic approach to functional GI disorders.

Standardized concept for the treatment of gastrointestinal dysmotility in critically ill patients--current status and future options

Inhibition of gastrointestinal motility is a major problem in critically ill patients. Motor stasis gives rise to subsequent complications including intolerance to enteral feeding, enhanced permeability of the atrophic intestinal mucosa and conditions as severe as systemic inflammatory response syndrome, sepsis and multiple organ failure. Although the diagnosis of motility disturbances in critically ill patients is difficult, the type and site of the disturbance are important to consider in the analysis of the condition and in the choice of therapeutic approach. The pharmacological treatment of impaired gastrointestinal motility is difficult to handle for the clinician, because the underlying mechanisms are complex and not fully understood and the availability of pharmacological treatment options is limited. In addition, there is a lack of controlled studies on which to build an evidence-based treatment concept for critically ill patients. Notwithstanding this situation, there has been remarkable progress in the understanding of the integrated regulation of gastrointestinal motility in health and disease. These advances, which largely relate to the organization of the enteric nervous system and its signaling mechanisms, enable the intensivist to develop a standardized concept for the use of prokinetic agents in the treatment of impaired gastrointestinal motility in critically ill patients.

Medical complications of surgical treatment of adult spinal deformity and how to avoid them

STUDY DESIGN

Review article of medical complications related to adult spinal deformity surgery.

OBJECTIVE

To identify medical complications related to surgery for adult spinal deformity and suggest ways to minimize their occurrence and to avoid them.

SUMMARY OF BACKGROUND DATA

Medical complications are a major consideration in adult spinal deformity surgery. Few studies have been done to identify the medical complication rate in relation to these procedures.

METHODS

We review the literature pertaining to medical complications regarding spinal deformity surgery.

RESULTS

Urinary tract infections are the most frequently seen complication. Additionally, pulmonary complications are the most common life-threatening complication. Medical complications are a frequent occurrence with adult deformity spinal surgery.

CONCLUSIONS

Awareness of the presentation, treatment, and prevention of medical complications of deformity surgery may allow minimization of their occurrence and optimize treatment should they occur.

Mechanisms of postoperative ileus

Postoperative ileus is an iatrogenic condition that follows abdominal surgery. Three main mechanisms are involved in its causation, namely neurogenic, inflammatory and pharmacological mechanisms. In the acute postoperative phase, mainly spinal and supraspinal adrenergic and non-adrenergic pathways are activated. Recent studies, however, show that the prolonged phase of postoperative ileus is caused by an enteric molecular inflammatory response and the subsequent recruitment of leucocytes into the muscularis of the intestinal segments manipulated during surgery. This inflammation impairs local neuromuscular function and activates neurogenic inhibitory pathways, inhibiting motility of the entire gastrointestinal tract. The mechanisms underlying the recruitment of the inflammatory cells, and their interaction with the intestinal afferent innervation, are discussed. Finally, opioids administered for postoperative pain control also contribute to a large extent to the reduction in propulsive gastrointestinal motility observed after abdominal surgery.

[Acute colonic pseudo-obstruction (Ogilvie's syndrome) in pneumococcal meningo-encephalitis treated with neostigmine]

We report the case of a 71-year-old man with acute colonic pseudo-obstruction that complicates a pneumococcal meningo-encephalitis. After 48 h of conservative management with nothing by mouth, nasogastric suction, fluid and electrolyte correction, withdrawal of any anticholinergic agents, a pharmacological approach with 2 mg of neostigmine was successful in intensive care unit. This treatment was effective in over 80% of patients of recent reports. Neostigmine might be considered as first-line therapy in patients who do not have major contraindications to its use, because of less frequent iatrogenic risk than colonoscopic decompression or surgery.

Pseudo-obstruction in the critically ill

Intestinal pseudo-obstruction is defined as a clinical syndrome characterized by impairment of intestinal propulsion, which may resemble intestinal obstruction, in the absence of a mechanical cause. It may involve the small and/or the large bowel, and may present in acute, subacute or chronic forms. We have performed a systematic review of acute pseudo-obstruction, also referred to as Ogilvie's syndrome in the literature, and focused on proposed mechanisms, manifestations and management of post-surgery and critically ill patients who suffer from one or more underlying clinical conditions. The hallmark of the syndrome is massive intestinal distension, which is detected on clinical inspection and plain abdominal radiography. The underlying pathophysiological mechanisms are not fully understood. Therefore, treatment focuses on preventing intestinal perforation, which is associated with an average 21% mortality rate.

Pseudo-obstruction in the critically ill

Intestinal pseudo-obstruction is defined as a clinical syndrome characterized by impairment of intestinal propulsion, which may resemble intestinal obstruction, in the absence of a mechanical cause. It may involve the small and/or the large bowel, and may present in acute, subacute or chronic forms. We have performed a systematic review of acute pseudo-obstruction, also referred to as Ogilvie's syndrome in the literature, and focused on proposed mechanisms, manifestations and management of post-surgery and critically ill patients who suffer from one or more underlying clinical conditions. The hallmark of the syndrome is massive intestinal distension, which is detected on clinical inspection and plain abdominal radiography. The underlying pathophysiological mechanisms are not fully understood. Therefore, treatment focuses on preventing intestinal perforation, which is associated with an average 21% mortality rate.

Postoperative ileus: etiologies and interventions

This article will review the pathophysiology of postoperative ileus, with emphasis on potential therapeutic targets, and examine the efficacy of pharmacologic and nonpharmacologic interventions. Proposed mechanisms include actuation of spinal and local sympathetic neural reflexes, inflammatory mediation, and exacerbation by anesthetic or surgical procedures. Some procedures or agents have shown clinical benefit, and these include use of laparoscopic surgery, thoracic epidurals, nonsteroidal anti-inflammatory drugs, and opiate antagonists. Other procedures may be helpful with low risk of adverse effects. These include early feeding and ambulation, laxatives, and possibly neostigmine.

Manejo clínico de la seudoobstrucción aguda de colon en el enfermo hospitalizado: revisión sistemática de la bibliografía

Intestinal pseudoobstruction is a clinical syndrome characterized by impairment of intestinal propulsion, which may resemble intestinal obstruction, in the absence of a mechanical cause. It usually affects the colon but the small intestine may also be involved, and may present in acute, subacute or chronic forms. We have performed a systematic review of the acute form of pseudoobstruction, also referred to as Ogilvie's syndrome. We discuss proposed pathophysiological mechanisms, manifestations and management of this clinical condition in post-surgery and critically ill patients. The hallmark of the syndrome is massive intestinal distension, which is detected on clinical inspection and plain abdominal radiography. The underlying pathophysiological mechanisms are not fully understood. Therefore, treatment has focussed on preventing intestinal perforation, which is associated with a 21% mortality rate.

Ileus in critical illness: mechanisms and management

Nonobstructive ileus, signifying the impairment of coordinated propulsive intestinal motility, remains a frequently documented and almost inevitable consequence of open abdominal surgery and sepsis. Despite the frequency and major impact of ileus on morbidity and mortality, the exact underlying molecular and cellular mechanisms of this important clinical conundrum are still ill defined. Animal models suggest that both neuronal and local inflammatory responses within the intestinal muscularis mechanistically contribute to intestinal ileus. The neuronal mechanism appears to involve the enhanced release of nitric oxide from inhibitory motor neurons. Likewise, nitric oxide and prostaglandins are released from inflammatory cells (macrophages and monocytes) via the induction of nitric oxide synthase (iNOS) and cyclooxygenase-2. Recently, preliminary data have confirmed the existence of an intraoperative local muscularis inflammatory response during surgery in human patients.