Postgrad Med J: first published as 10.1136/pgmj.69.807.48 on 1 January 1993. Downloaded from Postgrad Med J (1993) 69, 48 - 51 i) The Fellowship of Postgraduate Medicine, 1993

Missed Diagnosis Acute mesenteric ischaemia: the continuing difficulty in early diagnosis Steven D. Heys, Julie Brittenden and Trevor J. Crofts Department ofSurgery, University Medical Buildings, Foresterhill, Aberdeen AB9 2ZD, UK

Summary: Five cases of acute intestinal ischaemia due to occlusion ofthe superior mesenteric artery, all with a delay in diagnosis, are reported here. These cases illustrate the continuing difficulties, in clinical practice, in recognizing mesenteric ischaemia before intestinal has occurred, despite the clinical awareness of this condition.

Introduction The difficulty in recognizing acute intestinal ischae- tion. On abdominal examination there was vague mia in the early stages is well recognized because of central abdominal tenderness with no other signs; the few clinical signs that are present and it is not bowel sounds were normal and faecal occult blood until intestinal infarction has occurred that the testing was negative. Laboratory investigations diagnosis is made. As a result of this, the overall revealed a white blood cell count of 15.4 x 109/1by copyright. mortality of such patients is high (up to 80%), and and serum amylase was 465 IU/l. A diagnosis of furthermore, the overall survival has changed very suspected myocardial infarction was made and the little over the last 35 years.'-4 However, mesenteric patient managed conservatively, but required nar- arterial occlusion' is a condition that is amenable to cotic analgesics for increasing pain. In view of the surgical intervention, if it can be recognized and persisting abdominal pain, a surgical opinion was treated before intestinal necrosis has occurred, and requested. On examination (14 hours after admis- therefore reduce the mortality and post-operative sion to hospital), there was generalized abdominal morbidity of those surviving patients. tenderness with guarding and rebound, and absent

We report five cases of occlusion of the superior bowel sounds. Plain abdominal X-rays showed http://pmj.bmj.com/ mesenteric artery, with consequent widespread several dilated small intestinal loops. A diagnosis infarction of the , who presented to of , secondary to intestinal infarction, one surgical unit over a 12 month period. In all was made and laparotomy undertaken. At oper- cases there was a significant delay in making the ation, the small intestine, extending from 2 feet correct diagnosis. We examine the continuing distal to the duodenal-jejunal flexure to the trans- difficulties experienced by clinicians in making an verse colon was found to be necrotic. This was early and correct diagnosis. resected and a primary jejuno-colic anastomosis performed, following which the patient made a on September 25, 2021 by guest. Protected good postoperative recovery. Case reports Case 2 Case I A 74 year old man was admitted to hospital, after An 82 year old man was admitted to hospital with a being observed at home, with a 6 hour history of a history of a sudden onset of colicky abdominal sudden onset of severe epigastric pain associated pain, nausea and vomiting. It was noted that the with profuse vomiting and a history of myocardial patient had a history of hypertension and a myo- infarction 3 weeks previously. On examination, cardial infarction 2 years previously had been atrial fibrillation was noted and abdominal noted and examination had revealed atrial fibrilla- examination revealed distension and tenderness in the epigastrium, but there was no guarding or rebound tenderness and bowel sounds were normal. Correspondence: S.D. Heys, M.D., Ph.D., F.R.C.S.(Glas.) Laboratory investigations showed a white cell count Accepted: 31 March 1992 of 31.6 x 109/1, serum amylase was 1,177 IU/1 and Postgrad Med J: first published as 10.1136/pgmj.69.807.48 on 1 January 1993. Downloaded from ACUTE INTESTINAL ISCHAEMIA 49

plain abdominal X-rays showed several distended derness, rebound tenderness and guarding loops of small bowel with air/fluid levels. A diag- throughout, and faecal occult blood testing was nosis of acute was made on the clinical negative. Laboratory investigations showed a findings in conjunction with the elevated serum white blood cell count of 17.2 x 109/l, serum amylase, and the patient managed conservatively. amylase was 451 IU/l and plain abdominal X-rays The patient appeared to stabilize and improve showed several small bowel air-fluid levels. A clinically. However, 6 days after admission he diagnosis of mesenteric infarction was made and, deteriorated suddenly, becoming hypotensive with after a very short period of intensive resuscitation, obvious signs of generalized peritonitis. At this she proceeded to laparotomy. At operation the stage, 6 days after admission to hospital, it was whole ofthe small bowel was infarcted except for 2 decided to undertake laparotomy. At operation the feet of and proximal and 18 jejunum, and ascending colon were found to inches of terminal ileum. The cause of this was a be infarcted. A resection was carried out with a thrombosis/embolus in the superior mesenteric primary jejuno-colic anastomosis being performed artery and the necrotic intestine was resected with a and the patient made a good postoperative primary anastomosis carried out (if there are recovery initially. Unfortunately, however, he died doubts about the viability ofthe anastomosis, then from a massive gastrointestinal haemorrhage 7 superior mesenteric embolectomy may be worth- days later. A post-mortem examination revealed while). The patient made an uneventful recovery this to have come from a large gastric ulcer. and was discharged from hospital without any further problems. Case 3 Case S A 47 year old female was admitted to hospital, after being managed at home with a 36 hour history ofa A 46 year old man was admitted to hospital with a sudden onset of severe colicky, central abdominal 24 hour history of a sudden onset of central pain, associated with nausea and repeated vomit- abdominal colicky pain, vomiting and passing ing. There was no other significant past medical blood per . There was no significant past by copyright. history except that she was taking norethisterone medical history except for a sudden onset ofsevere, for menorrhagia. On examination she was noted to central crushing chest pain, one week previously be in severe pain with a sinus tachycardia (110/ which had been diagnosed as a myocardial infarc- minute) and a blood pressure of 110/65 mmHg. tion and managed at home without hospital admis- Abdominal examination revealed generalized ten- sion. Although the reason for the abdominal pain derness and guarding with absent bowel sounds was unclear, he was initially managed at home until and a negative faecal occult blood test. Plain the following day when he developed a sudden abdominal X-rays showed no abnormality, serum onset of a cold, painful, white leg and was then

amylase was 372 1U/l and white blood cell count referred to the Accident and Emergency Depart- http://pmj.bmj.com/ was 25.1 x 109/l. A diagnosis of generalized peri- ment. On examination he was hypotensive (80/40 tonitis secondary to a perforated viscus was made mmHg), with a sinus tachycardia of 120/minute. and laparotomy undertaken. At operation the Abdominal examination confirmed a generalized whole of the midgut extending from the second peritonitis with absent bowel sounds and examina- part ofthe duodenum to the distal transverse colon tion of his leg revealed an arterial occlusion distal was necrotic, and was associated with a thrombus to the femoral artery. Investigations revealed a or embolus at the origin of the superior mesenteric white blood cell count of 9.2 x 109/l, but plain artery. The patient subsequently died and a post- radiography of the abdomen was not carried out. on September 25, 2021 by guest. Protected mortem examination confirmed a thrombotic He was resuscitated and proceeded to laparotomy, occlusion at the origin of the superior mesenteric where the whole of the small bowel except for 12 artery, although no other abnormalities or predis- inches of proximal jejunum was infarcted. All this posing factors could be found. small bowel was resected, after exploration and removal of an embolus from the superior mesen- Case 4 teric artery had failed to improve the situation. In addition, he underwent a femoral embolectomy, A 72 year old female was admitted to hospital, after with the successful restoration of arterial circula- being managed at home with a 72 hour history ofa tion to the leg, and made a good recovery. sudden onset of upper abdominal colicky pain associated with nausea and vomiting. There was no significant past medical history. On examination Discussion she was centrally cyanosed, with a sinus tachycar- dia and systolic blood pressure of 60 mmHg. The peak incidence of mesenteric infarction is in Abdominal examination revealed generalized ten- the six and seventh decades and there appears to be Postgrad Med J: first published as 10.1136/pgmj.69.807.48 on 1 January 1993. Downloaded from 50 S.D. HEYS et al. an equal male to female distribution,2'5 although Patients are frequently apyrexial and up to half some studies have found a male preponderance.6'7 experience loose bowel movements initially, prob- Mesenteric infarction may occur not only as a ably due to increased intestinal activity.3 Faecal result of occlusion of the superior mesenteric occult blood testing is usually negative in the early artery, but also because of thrombosis of the stages of ischaemia and it is not until mucosal superior mesenteric vein and also 'spasm' of the infarction has occurred that it becomes positive.5 intestinal circulation. There are certain causal and Hypotension and shock is also common, initially predisposing factors for mesenteric infarction due to a loss ofintravascular and extracellular fluid (Table I) but in up to 50% of patients with into the intestinal lumen,7 although later septi- mesenteric infarction, no obvious cause can be caemic shock may occur because of intestinal found.89 necrosis and the resultant translocation of intes- The mortality ofpatients who experience mesen- tinal bacteria form the gut lumen into the systemic teric infarction continues to be high, with up to circulation. 80% ofsuch patients dying.'4-This may be explain- All the patients in our series had complained ofa ed, in part, by the continuing difficulties the sudden onset of central or upper abdominal pain clinician has in making the correct diagnosis at an and all of them (except one in whom there was no early stage, before intestinal infarction has occur- known cause), had well-recognized risk factors for red and the patient has become septicaemic with its mesenteric infarction - atrial fibrillation, recent attendant complications and sequelae. The small myocardial infarction and hormone replacement intestine can withstand only up to 6 hours of therapy with progestogens alone. However, despite ischaemia before irreversible changes occur,'0 and their clinical histories and the presence of clearly the shorter the duration of symptoms the more identifiable risk factors, there was a mean time likely is the patient to survive after surgery.9 delay in the diagnosis of mesenteric infarction, by In the early stages of mesenteric ischaemia the surgeons, physicians and general practitioners, of patients complain of upper or central abdominal 50 hours (range 16-104 hours) in these patients. pain, which is frequently colicky and of a sudden Although the importance of a thorough clinical onset associated with vomiting, and often cold history and examination cannot be understated, itby copyright. sweating which is believed to be due to massive would be ofconsiderable help ifthere were labora- sympathetic nervous activity.3 However, abdomi- tory investigations that which could be ofhelp. The nal examination frequently reveals minimal signs small intestine is a rich source of phosphate and and it is not until intestinal infarction has taken experimental animal studies have shown that in the place that there are then the more easily recognized early stages of intestinal ischaemia and before signs of generalized or localized peritonitis. Often necrosis has supervened, the serum phosphate is great emphasis is placed on the bowel sounds but significantly elevated. This has been evaluated in these are present, and often hyperactive, at the patients with mesenteric infarction, with 80%

onset of mesenteric ischaemia. They are only having elevations in serum phosphate, although http://pmj.bmj.com/ absent when intestinal infarction has occurred. bowel infarction had occurred." In addition, these authors found that there was an associated meta- bolic acidosis and leucocytosis and they believed Table I Type and risk factors for mesenteric infarc- that this triad strongly supported a diagnosis of tion intestinal ischaemia."' It is important to note that serum amylase may also be elevated in approx- Type Risk factors imately half of patients with intestinal infarction, and in 6% of them can be elevated to such levels on September 25, 2021 by guest. Protected Superior mesenteric Atheroma, congestive cardiac that a misdiagnosis of might be artery thrombosis failure, hypotension, oral made.9 Indeed, patient 2 in our series had a greatly contraceptives elevated amylase and a diagnosis of pancreatitis Superior mesenteric Myocardial infarction, artery embolus arrhythmias, ventricular was made. This had resulted in laparotomy being aneurysm, endocarditis, delayed until 6 days after the patient had been atheroma admitted to hospital. Therefore, if patients in Superior mesenteric Primary mesenteric occlusion, whom a diagnosis of acute pancreatitis has been venous thrombosis , oral contraceptives, made fail to settle adequately, then mesenteric thrombocytosis, disseminated infarction must be considered. Plain radiographs of intravascular coagulation, the abdomen may not be helpful; some patients postsplenectomy may have air fluid levels in small and/or large Non-occlusive Digoxin or propranolol over- infarction dose, hypotension, sepsis, intestine in the early stages, but more than one third shock, myocardial infarction ofthe patients have no abnormality on first presen- Unknown tation.3 Angiography may have a role to play in specialized centres where it is readily available,9"10 Postgrad Med J: first published as 10.1136/pgmj.69.807.48 on 1 January 1993. Downloaded from ACUTE INTESTINAL ISCHAEMIA 51 although there are drawbacks - the risk of the when there are known risk factors present. At the procedure, negative investigations and finding an present time there are no reliable laboratory indic- already occluded artery which had been asympto- ators of intestinal ischaemia and a heightened matic. More recently, experimental studies have awareness of the clinical problem in conjunction been investigating the use of magnetic resonance with early access to angiography represent two imaging as a non-invasive method of diagnosing significant factors in improving management of intestinal ischaemia,'2 but this requires thorough this surgical emergency. evaluation before applied to man in the clinical situation. Clearly, in retrospect, the diagnosis of mesen- teric infarction should have been made readily in Acknowledgements four of the five cases, but the key to early diagnosis must lie in a high index of suspicion of this We would like to thank the various consultants concerned condition, especially when the severity of the for permission to report their patients and Professor 0. abdominal pain exceeds the physical signs and Eremin for reading the manuscript.

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