Acute mechanical bowel obstruction: Clinical presentation, etiology, management and outcome

AIM: To identify and analyze the clinical presentation, management and outcome of patients with acute mechanical bowel obstruction along with the etiology of obstruction and the incidence and causes of bowel ischemia, necrosis, and perforation. METHODS: This is a prospective observational study of all adult patients admitted with acute mechanical bowel obstruction between 2001 and 2002. RESULTS: Of the 150 consecutive patients included in the study, 114 (76%) presented with small bowel and 36 (24%) with large bowel obstruction. Absence of passage of flatus (90%) and/or feces (80.6%) and abdominal distension (65.3%) were the most common symptoms and physical finding, respectively. Adhesions (64.8%), incarcerated hernias (14.8%), and large bowel cancer (13.4%) were the most frequent causes of obstruction. Eighty-eight patients (58.7%) were treated conservatively and 62 (41.3%) were operated (29 on the first day). Bowel ischemia was found in 21 cases (14%), necrosis in 14 (9.3%), and perforation in 8 (5.3%). Hernias, large bowel cancer, and adhesions were the most frequent causes of bowel ischemia (57.2%, 19.1%, 14.3%), necrosis (42.8%, 21.4%, 21.4%), and perforation (50%, 25%, 25%). A significantly higher risk of strangulation was noticed in incarcerated hernias than all the other obstruction causes. CONCLUSION: Absence of passage of flatus and/or feces and abdominal distension are the most common symptoms and physical finding of patients with acute mechanical bowel obstruction, respectively. Adhesions, hernias, and large bowel cancer are the most commoncauses of obstruction, as well as of bowel ischemia, necrosis, and perforation. Although an important proportion of these patients can be nonoperatively treated, a substantial portion requires immediate operation. Great caution should be taken for the treatment of these patients since the incidence of bowel ischemia, necrosis, and perforation is significantly high.

Mechanical intestinal obstruction due to isolated diffuse venous malformations in the gastrointestinal tract: A case report and review of literature

BACKGROUND Isolated gastrointestinal venous malformations(GIVMs)are extremely rare congenital developmental abnormalities of the venous vasculature.Because of their asymptomatic nature,the diagnosis is often quite challenging.However,as symptomatic GIVMs have nonspecific clinical manifestations,misdiagnosis is very common.Here,we report a case of isolated diffuse GIVMs inducing mechanical intestinal obstruction.A literature review was also conducted to summarize clinical features,diagnostic points,treatment selections and differential diagnosis in order that doctors may have a comprehensive understanding of this disease.CASE SUMMARY A 50-year-old man presented with recurrent painless gastrointestinal bleeding for two months and failure to pass flatus and defecate with nausea and vomiting for ten days.Digital rectal examination found bright red blood and soft nodular masses 3 cm above the anal verge.Computed tomography showed that part of the descending colon and rectosigmoid colon was thickened with phleboliths in the intestinal wall.Colonoscopy exhibited bluish and reddish multinodular submucosal masses and flat submucosal serpentine vessels.Endoscopic ultrasonography showed anechoic cystic spaces within intestinal wall.The lesions were initially thought to be isolated VMs involving part of the descending colon and rectosigmoid colon.Laparoscopic subtotal proctocolectomy,pullthrough transection and coloanal anastomosis and ileostomy were performed.Histopathology revealed intact mucosa and dilated,thin-walled blood vessels in the submucosa,muscularis,and serosa involving the entire colorectum.The patient recovered with complete symptomatic relief during the 52-mo follow-up period.CONCLUSION The diagnosis of isolated GIVMs is challenging.The information presented here is significant for the diagnosis and management of symptoms.

Effects of extrinsic positive end-expiratory pressure on work of breathing in patients with chronic obstructive pulmonary disease

Objective To investigate the effects of extrinsic positive end-expiratory pressure (PEEPe) on work of breathing in patients with chronic obstructive pulmonary disease (COPD) and their corresponding mechanism.Methods Ten ventilated patients with COPD were included in the study. A Bicore CP-100 pulmonary monitor (Bicore Monitoring System, USA) was used for monitoring respiratory mechanics. First, dynamic intrinsic positive end-expiratory pressure (PEEPi,dyn) was measured when PEEPe was zero, which was called PEEPi,dynz. Then the PEEPe was set randomly at 0%, 40%, 60%, 80% and 100% of PEEPi,dynz respectively. Pulmonary mechanics and other parameters (heart rate, blood pressure and blood gas analysis) were measured 30 minutes after the level of PEEPe was changed.Results Work of breathing patient (WOBp), pressure time product, difference of esophageal pressure and PEEPi,dyn decreased significantly when PEEPe was applied, and continued decreasing as PEEPe was increased. Work of breathing ventilator increased significantly when PEEPe was increased to 80% and 100% of PEEPi,dynz. Significantly positive linear correlation was found between the changes in WOBp and in PEEPi,dyn.Conclusions WOBp decreases gradually as PEEPe is increased. WOBp decreases by narrowing the difference between the alveolus pressure and the central airway pressure at the end of expiration when PEEPe is applied.

Effects of extrinsic positive end-expiratory pressure on cardiopulmonary function in patients with chronic obstructive pulmonary disease

Objective To choose one optimal extrinsic positive end-expiratory pressure (PEEPe) for ventilated patients with chronic obstructive pulmonary disease (COPD) and to compare two methods for choosing the optimal level of PEEPe.Methods Ten ventilated patients with COPD were included in the study. First, static intrinsic positive end-expiratory pressure (PEEPi,st) was measured when PEEPe was zero, and the PEEPi,st was called PEEPi,stz. PEEPe at 0%, 40%, 50%, 60%, 70%, 80%, 90% and 100% of PEEPi,stz, respectively, were applied randomly. Respiratory mechanics, hemodynamics, and oxygen dynamics were recorded 30 minutes after the level of PEEPe was changed.Results When PEEPe was not higher than 80% of PEEPi,stz, no measurement changed significantly. When PEEPe was increased to 90% and 100% of PEEPi,stz, PEEPi,st, peak inspiratory pressure, plateau pressure, pulmonary capillary wedge pressure and central venous pressure increased significantly, P<0.01. Cardiac output and left ventricular work index decreased significantly, P<0.01. Oxygen delivery decreased significantly, P<0.05. When PEEPe was increased to 100% of PEEPi,stz, the right ventricular work index decreased significantly, P<0.05.Conclusion Eighty percent of PEEPi,stz was the upper limit of PEEPe. The results of the two methods used to set the level of PEEPe were identical.