- Email: [email protected]
Syndrome of the rectus abdominis muscle mimicking the acute abdomen
CASE REPORT syndromes, rectus abdominis muscle; trauma, rectus abdominis muscle
Syndrome of the Rectus Abdominis Muscle Mimicking the Acute Abdomen The syndrome of the rectus abdominis muscle is a disorder of unknown etiology that produces rupture or tear of the epigastric artery, and stretches the rectus cutaneous medialis nerve, producing excruciating pain. The disorder is misdiagnosed in 60% to 93% of cases. We report two cases that presented as acute abdomen. One helpful diagnostic test was the lidocaine test, accomplished by subcutaneous injection of lidocaine into the sheath of the rectus abdominis muscle near the rectus cutaneous medialis nerve; the procedure provided i m m e d i a t e pain relief and the patients remained asymptomatic. In addition to helping establish a diagnosis quickly the lidocaine test may spare the patient the unnecessary morbidity or mortality of more invasive procedures. [Hughes GS, Treadwell EL, Miller J: Syndrome of the rectus abdominis muscle mimicking the acute abdomen. Ann Emerg Med July 1985;14:694-695.]
INTRODUCTION The syndrome of the rectus abdominis muscle (RAM) m a y m i m i c the acute abdomen. It occurs more frequently than is generally recognized, I,2 and it often results in unnecessary pain and expense to the patient. The purpose of our report is to show that the syndrome of the RAM must be included in the differential diagnosis of the acute abdomen and that the lidocaine test, the local subcutaneous administration of lidocaine into the rectus cutaneous medialis nerve, can provide immediate relief and may be a costeffective aid to correct diagnosis.
George S Hughes, Jr, MD Edward L Treadwell, MD Jeffrey Miller, MD Greenville, North Carolina From the Department of Medicine, East Carolina University School of Medicine, Greenville, North Carolina. Received for publication October 17, 1984. Revision received December 7, 1984. Accepted for publication January 21, 1985. Address for reprints: George S Hughes, Jr, MD, FACP, Department of Pharmacology, Medical University of South Carolina, 171 Ashley Avenue, Charleston, South Carolina 29425.
CASE REPORTS Case Number One A 45-year-old man presented with the acute onset of severe midepigastric and left anterior chest pain that began while he was driving to work. The pain radiated to the back and was accompanied by nausea, vomiting, diaphoresis, and tachycardia. The patient had suffered a myocardial infarction nine years before. At the time of admission, he was being treated for hypertension with 50 mg oral hydrochlorothiazide once daily. This pain was m u c h more severe than that accompanying his previous myocardial infarction. The vital signs were as follows: blood pressure, 220/120 m m Hg; pulse, 120; respirations, 30; and temperature, 37.5 C. The remainder of the cardiovascular and respiratory examination was normal, and a rectal examination was normal. The abdominal rectus sheath was tender to the touch over the aponeurosis and left lateral border of the RAM. Laboratory studies included a white blood cell count of 24,500/mm 3, but the differential, hemoglobin, hematocrit, and indices were normal. Serum amylase, urinalysis, platelet count, prothrombin time (PT), activated partial t h r o m b o p l a s t i n time (PTT), s e r u m c h e m i s t r y profile (SMA-12), cardiac enzymes, chest radiograph, chest c o m p u t e d t o m o g r a p h y scan including views of the thoracic and abdominal aorta, abdominal ultrasound, intravenous pyelogram (IVP), serial electrocardiograms, arterial blood gases, erythrocyte sedimentation rate, and urinalysis were within normal limits. A Swan-Ganz catheter was placed in the right pulmonary artery prior to antihypertensive treatment with intravenous (IV) nitroprusside 0.5 ~g/kg/ min (37.5 ~g/min). This resulted in the prompt reduction of blood pressure to 150/90 m m Hg within minutes. IV morphine at 2 mg every 10 to 15
14:7 July 1985
Annals of Emergency Medicine
694/119
RECTUS ABDOMINIS MUSCLE Hughes, Treadwell & Miller
m i n u t e s for a total of 40 mg only partially alleviated the pain. Because of t h e f a i l u r e to d e m o n strate a d i s s e c t i n g a o r t i c a n e u r y s m , myocardial infarction, or an overt intraabdominal lesion, the diagnosis of the syndrome of the RAM was entertained. T h e l i d o c a i n e t e s t was performed according to the technique described by Komar, 3 in w h i c h a local subcutaneous injection of 5 mL 1% lidocaine was given over the distribut i o n of e a c h of t h e l e f t s e v e n t h through the twelfth intercostal nerve insertions, the aponeurosis, and the left lateral border of the RAM. This produced i m m e d i a t e and dramatic relief of the pain. The patient remained a s y m p t o m a t i c w i t h no further abdominal pain.
Case Number Two A 2S-year-old woman presented w i t h right side f l a n k pain, dysuria, and abdominal cramping w i t h o u t nausea, vomiting, chills or fever. Three m o n t h s prior to admission, she had undergone an exploratory laparotomy for the s a m e symptomatology. Findings at surgery were u n r e m a r k a b l e . The patient stated that her pain was the same as it was before surgery. T h e physical e x a m i n a t i o n revealed a young w o m a n in moderate distress. Vital signs were as follows: blood pressure, 118/70 m m Hg; pulse, 69 and regular; r e s p i r a t i o n s , 16; a n d t e m perature, 36.1 C. There was m a r k e d t e n d e r n e s s to p a l p a t i o n in t h e left lower quadrant. The rest of the physical e x a m i n a t i o n , .including a pelvic examination, was unremarkable. The laboratory evaluation included a normal white blood cell count and differential; hemoglobin, h e m a t o c r i t , and indices. The urinalysis was unrem a r k a b l e , and an e r y t h r o c y t e sedimentation rate also was normal. S e r u m c h e m i s t r y p r o f i l e (SMA-12), serum amylase, PT, activated PTT, flat p l a t e of t h e a b d o m e n , a b d o m i n a l ultrasound, air contrast barium enema,.IVP, and cystoscopy were unremarkable. A serum pregnancy test was negative. After failing to demonstrate serious intraabdominal disorders the diagnosis of the RAM syndrome was considered. The lidocaine test was a d m i n i s t e r e d
120/695
as in case n u m b e r one, and i m m e d i a t e relief of the pain occurred. The patient remained asymptomatic.
ranges between 4% and 5%; for pregnant patients, however, the rate may be as high as 15%, w i t h a fetal mortality rate approaching 50%. 10
DISCUSSION T h e s y n d r o m e of the R A M often p r e s e n t s as an a c u t e a b d o m e n and m a y lead to unnecessary invasive procedures if the syndrome is not readily considered. Our cases were typical of those previously reported in the litera t u r e . 3 Each case p r e s e n t e d as an a c u t e a b d o m e n , b u t l a b o r a t o r y and roentgenographic studies were unremarkable.Z Indeed pain in the right lower quadrant as in case n u m b e r two was f o u n d in a p p r o x i m a t e l y half of previously documented cases.4, 5 Each case presented a diagnostic challenge and included a broad differential diagnosis of acute m y o c a r d i a l infarction, d i s s e c t i n g a o r t i c a n e u r y s m , or t h e myriad causes of an acute abdomen. Komar 3 suggested that a local injection of 5 mL 1% lidocaine into the sheath of the RAM in the distribution of the rectus cutaneous medialis nerve c o u l d be a u s e f u l d i a g n o s t i c a n d therapeutic procedure. In both of our cases dramatic and i m m e d i a t e relief of pain occurred following this technique. A p p r o x i m a t e l y 5 0 % of cases have no predisposing factors and are best classified as idiopathic, z as were our cases. Muscle r u p t u r e or tear of the epigastric artery, 2-~o however, m a y occur w i t h blunt abdominal t r a u m a or s u d d e n m u s c l e e x e r t i o n s u c h as coughing, vomiting, seizure activity, or e x e r c i s e . N u m e r o u s c a s e s h a v e been associated w i t h pneumonia, inf l u e n z a , t y p h o i d fever, h e m o r r h a g e from anticoagulant therapy, underlying h e m a t o l o g i c diseases, h y p e r t e n sion, hypothyroidism, patients on hem o d i a l y s i s or p e r i t o n e a l d i a l y s i s , 9 h y p o t h y r o i d i s m , 4 and pregnancy.2,to Previous abdominal surgery accounts for fewer than 5% of cases, z Pregnancy is believed to be a special cause of R A M s y n d r o m e in w h i c h such factors as multiparity, age more than 30 years, and c o n c o m i t a n t respiratory infections increase the risk of the syndrome.2, 5 The disorder has a 3:1 ratio of w o m e n to men. to If surgery is p e r f o r m e d for d i a g n o s t i c or therapeutic reasons, the m o r t a l i t y rate
Annals of Emergency Medicine
SUMMARY The syndrome of the RAM should be considered in the differential diagnosis of all p a t i e n t s presenting with acute abdomen because the correct diagnosis m a y spare the patient excessive cost, morbidity, and possibly mortality from invasive procedures. The lidocaine test m a y be a simple but effective technique by w h i c h to establish the diagnosis of the R A M syndrome. The authors thank Eugene Furth, MD, for his review and helpful comments.
REFERENCES t. Simon BC, Rosen P: Abdominal wall hematoma: Case report and subject review. Journal of Emergency Medicine 1984; 1:219-222. 2. Titone C, Lipisus M, Krakauer JS: "Spontaneous" hematoma of the rectus abdominis muscle: Critical review of 50 cases with emphasis on early diagnosis and treatment. Surgery 1972;72:568-572. 3. Komar J, Varga B: Syndrome of the rectus abdominis muscle. J Neurol 1975;210: 121-125. 4. Stirrat GM, McLaughlin IS, Struthers JO, et ah Haematoma of the. rectus abd o m i n a l muscle. Br [ Surg 1970;57: 175-178. 5. Beattie JL: Spontaneous rupture of the rectus abdominis muscle. J Iowa Med Soc 1965;55:696-698. 6. Backwinkel L: Rupture of the rectus abdominis muscle. Arch Surg 1965;90: 35-37. 7. Teske JM: Hematoma of the rectus abdominis muscle: Report of a case and analysis of 100 cases from the literature. lournal of Surgery 1946;71:689-692. 8. Jones TW, Merendino KA: The deep epigastric artery: Rectus muscle syndrome. Am J Surg 1962;103:159-169. 9. DeSanto NG, Capodicasa G, Perna N, et al: Hematoma of rectus abdominis associated with dialysis. Br Med J (Clin Res) 1972;3:281-282. 10. Solano S, Coppola P: Rectus abdominis muscle hematoma in pregnancy. Va Med Mon 1973;100:340-343.
14:7 July i985
Syndrome of the Rectus Abdominis Muscle Mimicking the Acute Abdomen The syndrome of the rectus abdominis muscle is a disorder of unknown etiology that produces rupture or tear of the epigastric artery, and stretches the rectus cutaneous medialis nerve, producing excruciating pain. The disorder is misdiagnosed in 60% to 93% of cases. We report two cases that presented as acute abdomen. One helpful diagnostic test was the lidocaine test, accomplished by subcutaneous injection of lidocaine into the sheath of the rectus abdominis muscle near the rectus cutaneous medialis nerve; the procedure provided i m m e d i a t e pain relief and the patients remained asymptomatic. In addition to helping establish a diagnosis quickly the lidocaine test may spare the patient the unnecessary morbidity or mortality of more invasive procedures. [Hughes GS, Treadwell EL, Miller J: Syndrome of the rectus abdominis muscle mimicking the acute abdomen. Ann Emerg Med July 1985;14:694-695.]
INTRODUCTION The syndrome of the rectus abdominis muscle (RAM) m a y m i m i c the acute abdomen. It occurs more frequently than is generally recognized, I,2 and it often results in unnecessary pain and expense to the patient. The purpose of our report is to show that the syndrome of the RAM must be included in the differential diagnosis of the acute abdomen and that the lidocaine test, the local subcutaneous administration of lidocaine into the rectus cutaneous medialis nerve, can provide immediate relief and may be a costeffective aid to correct diagnosis.
George S Hughes, Jr, MD Edward L Treadwell, MD Jeffrey Miller, MD Greenville, North Carolina From the Department of Medicine, East Carolina University School of Medicine, Greenville, North Carolina. Received for publication October 17, 1984. Revision received December 7, 1984. Accepted for publication January 21, 1985. Address for reprints: George S Hughes, Jr, MD, FACP, Department of Pharmacology, Medical University of South Carolina, 171 Ashley Avenue, Charleston, South Carolina 29425.
CASE REPORTS Case Number One A 45-year-old man presented with the acute onset of severe midepigastric and left anterior chest pain that began while he was driving to work. The pain radiated to the back and was accompanied by nausea, vomiting, diaphoresis, and tachycardia. The patient had suffered a myocardial infarction nine years before. At the time of admission, he was being treated for hypertension with 50 mg oral hydrochlorothiazide once daily. This pain was m u c h more severe than that accompanying his previous myocardial infarction. The vital signs were as follows: blood pressure, 220/120 m m Hg; pulse, 120; respirations, 30; and temperature, 37.5 C. The remainder of the cardiovascular and respiratory examination was normal, and a rectal examination was normal. The abdominal rectus sheath was tender to the touch over the aponeurosis and left lateral border of the RAM. Laboratory studies included a white blood cell count of 24,500/mm 3, but the differential, hemoglobin, hematocrit, and indices were normal. Serum amylase, urinalysis, platelet count, prothrombin time (PT), activated partial t h r o m b o p l a s t i n time (PTT), s e r u m c h e m i s t r y profile (SMA-12), cardiac enzymes, chest radiograph, chest c o m p u t e d t o m o g r a p h y scan including views of the thoracic and abdominal aorta, abdominal ultrasound, intravenous pyelogram (IVP), serial electrocardiograms, arterial blood gases, erythrocyte sedimentation rate, and urinalysis were within normal limits. A Swan-Ganz catheter was placed in the right pulmonary artery prior to antihypertensive treatment with intravenous (IV) nitroprusside 0.5 ~g/kg/ min (37.5 ~g/min). This resulted in the prompt reduction of blood pressure to 150/90 m m Hg within minutes. IV morphine at 2 mg every 10 to 15
14:7 July 1985
Annals of Emergency Medicine
694/119
RECTUS ABDOMINIS MUSCLE Hughes, Treadwell & Miller
m i n u t e s for a total of 40 mg only partially alleviated the pain. Because of t h e f a i l u r e to d e m o n strate a d i s s e c t i n g a o r t i c a n e u r y s m , myocardial infarction, or an overt intraabdominal lesion, the diagnosis of the syndrome of the RAM was entertained. T h e l i d o c a i n e t e s t was performed according to the technique described by Komar, 3 in w h i c h a local subcutaneous injection of 5 mL 1% lidocaine was given over the distribut i o n of e a c h of t h e l e f t s e v e n t h through the twelfth intercostal nerve insertions, the aponeurosis, and the left lateral border of the RAM. This produced i m m e d i a t e and dramatic relief of the pain. The patient remained a s y m p t o m a t i c w i t h no further abdominal pain.
Case Number Two A 2S-year-old woman presented w i t h right side f l a n k pain, dysuria, and abdominal cramping w i t h o u t nausea, vomiting, chills or fever. Three m o n t h s prior to admission, she had undergone an exploratory laparotomy for the s a m e symptomatology. Findings at surgery were u n r e m a r k a b l e . The patient stated that her pain was the same as it was before surgery. T h e physical e x a m i n a t i o n revealed a young w o m a n in moderate distress. Vital signs were as follows: blood pressure, 118/70 m m Hg; pulse, 69 and regular; r e s p i r a t i o n s , 16; a n d t e m perature, 36.1 C. There was m a r k e d t e n d e r n e s s to p a l p a t i o n in t h e left lower quadrant. The rest of the physical e x a m i n a t i o n , .including a pelvic examination, was unremarkable. The laboratory evaluation included a normal white blood cell count and differential; hemoglobin, h e m a t o c r i t , and indices. The urinalysis was unrem a r k a b l e , and an e r y t h r o c y t e sedimentation rate also was normal. S e r u m c h e m i s t r y p r o f i l e (SMA-12), serum amylase, PT, activated PTT, flat p l a t e of t h e a b d o m e n , a b d o m i n a l ultrasound, air contrast barium enema,.IVP, and cystoscopy were unremarkable. A serum pregnancy test was negative. After failing to demonstrate serious intraabdominal disorders the diagnosis of the RAM syndrome was considered. The lidocaine test was a d m i n i s t e r e d
120/695
as in case n u m b e r one, and i m m e d i a t e relief of the pain occurred. The patient remained asymptomatic.
ranges between 4% and 5%; for pregnant patients, however, the rate may be as high as 15%, w i t h a fetal mortality rate approaching 50%. 10
DISCUSSION T h e s y n d r o m e of the R A M often p r e s e n t s as an a c u t e a b d o m e n and m a y lead to unnecessary invasive procedures if the syndrome is not readily considered. Our cases were typical of those previously reported in the litera t u r e . 3 Each case p r e s e n t e d as an a c u t e a b d o m e n , b u t l a b o r a t o r y and roentgenographic studies were unremarkable.Z Indeed pain in the right lower quadrant as in case n u m b e r two was f o u n d in a p p r o x i m a t e l y half of previously documented cases.4, 5 Each case presented a diagnostic challenge and included a broad differential diagnosis of acute m y o c a r d i a l infarction, d i s s e c t i n g a o r t i c a n e u r y s m , or t h e myriad causes of an acute abdomen. Komar 3 suggested that a local injection of 5 mL 1% lidocaine into the sheath of the RAM in the distribution of the rectus cutaneous medialis nerve c o u l d be a u s e f u l d i a g n o s t i c a n d therapeutic procedure. In both of our cases dramatic and i m m e d i a t e relief of pain occurred following this technique. A p p r o x i m a t e l y 5 0 % of cases have no predisposing factors and are best classified as idiopathic, z as were our cases. Muscle r u p t u r e or tear of the epigastric artery, 2-~o however, m a y occur w i t h blunt abdominal t r a u m a or s u d d e n m u s c l e e x e r t i o n s u c h as coughing, vomiting, seizure activity, or e x e r c i s e . N u m e r o u s c a s e s h a v e been associated w i t h pneumonia, inf l u e n z a , t y p h o i d fever, h e m o r r h a g e from anticoagulant therapy, underlying h e m a t o l o g i c diseases, h y p e r t e n sion, hypothyroidism, patients on hem o d i a l y s i s or p e r i t o n e a l d i a l y s i s , 9 h y p o t h y r o i d i s m , 4 and pregnancy.2,to Previous abdominal surgery accounts for fewer than 5% of cases, z Pregnancy is believed to be a special cause of R A M s y n d r o m e in w h i c h such factors as multiparity, age more than 30 years, and c o n c o m i t a n t respiratory infections increase the risk of the syndrome.2, 5 The disorder has a 3:1 ratio of w o m e n to men. to If surgery is p e r f o r m e d for d i a g n o s t i c or therapeutic reasons, the m o r t a l i t y rate
Annals of Emergency Medicine
SUMMARY The syndrome of the RAM should be considered in the differential diagnosis of all p a t i e n t s presenting with acute abdomen because the correct diagnosis m a y spare the patient excessive cost, morbidity, and possibly mortality from invasive procedures. The lidocaine test m a y be a simple but effective technique by w h i c h to establish the diagnosis of the R A M syndrome. The authors thank Eugene Furth, MD, for his review and helpful comments.
REFERENCES t. Simon BC, Rosen P: Abdominal wall hematoma: Case report and subject review. Journal of Emergency Medicine 1984; 1:219-222. 2. Titone C, Lipisus M, Krakauer JS: "Spontaneous" hematoma of the rectus abdominis muscle: Critical review of 50 cases with emphasis on early diagnosis and treatment. Surgery 1972;72:568-572. 3. Komar J, Varga B: Syndrome of the rectus abdominis muscle. J Neurol 1975;210: 121-125. 4. Stirrat GM, McLaughlin IS, Struthers JO, et ah Haematoma of the. rectus abd o m i n a l muscle. Br [ Surg 1970;57: 175-178. 5. Beattie JL: Spontaneous rupture of the rectus abdominis muscle. J Iowa Med Soc 1965;55:696-698. 6. Backwinkel L: Rupture of the rectus abdominis muscle. Arch Surg 1965;90: 35-37. 7. Teske JM: Hematoma of the rectus abdominis muscle: Report of a case and analysis of 100 cases from the literature. lournal of Surgery 1946;71:689-692. 8. Jones TW, Merendino KA: The deep epigastric artery: Rectus muscle syndrome. Am J Surg 1962;103:159-169. 9. DeSanto NG, Capodicasa G, Perna N, et al: Hematoma of rectus abdominis associated with dialysis. Br Med J (Clin Res) 1972;3:281-282. 10. Solano S, Coppola P: Rectus abdominis muscle hematoma in pregnancy. Va Med Mon 1973;100:340-343.
14:7 July i985