At least one in two SA patients presents with a medical history of recent abdominal surgery. Onset of SA-associated symptoms typically occurs one or two months after such an intervention.

Both non-specific symptoms like fever, chills and anorexia as well as signs that indicate an abdominal lesion with respiratory compromise may be presented. The latter manifests in form of abdominal pain, tenderness over the inferior ribs, hiccup, dyspnea and tachycardia and non-productive cough. Pneumonia may develop. Additionally, gastrointestinal disorders like ileus may be reported. In some cases, pathological reduction of bowel movements may be the only symptom of an SA.

Abdominal wall tension increases if focal or generalized peritonitis develops; accordingly, an enhanced tension may be noted in the upper abdominal region, preferentially on the side of the abscess, or the whole abdomen may be affected. Patients with peritonitis have a high risk of developing sepsis, and sepsis is related to symptoms like high fever, hypotension, tachycardia, tachypnea, impairment of renal function and eventually shock and multiple organ failure.

Of note, persistence of post-operative symptoms and application of analgesics, anti-inflammatory drugs and possibly even antibiotics may mask this disease. This has been reported, for instance, in patients treated with microwave or radiofrequency ablation because of liver cancer [8].

• Fever

  CASE REPORT A 22-month-old boy with no significant medical history was well until 8 days before admission, when he presented with fever to 104°F. [pediatrics.aappublications.org]

  […] of unknown etiology" "hectic fever" PUS somewhere, PUS nowhere, Pus is there � under diaphragm. mInvestigations: A- Plain x-ray �on abdomen in erect position ; Elevation of the copula of diaphragm. ; Gas with fluid level under diaphragm. ; Thickening [meduweb.com]

  The authors describe a young girl presenting with fever and respiratory distress and a chest x-ray showing a left lower lobe infiltrate and an effusion. She also had splenomegaly. [ncbi.nlm.nih.gov]

• Chills

  Presents with cough, increased respiratory rate with shallow respiration, diminished or absent breath sounds, hiccups, dullness in percussion, tenderness over the 8th–11th ribs, fever, chills, anorexia and shoulder tip pain on the affected side. [en.wikipedia.org]

  There was no history of fever, chills, vomiting, or abdominal pain. There was a history of non-insulin-dependent diabetes. .. José L. Zambrana, M.D., Ph.D. Juan A. García-Gutiérrez, M.D. Felipe Díez, M.D., Ph.D. [nejm.org]

  Both non-specific symptoms like fever, chills and anorexia as well as signs that indicate an abdominal lesion with respiratory compromise may be presented. [symptoma.com]

  Fever, the most common finding in liver abscess, may be accompanied by chills and sweats. The second most common finding is right upper quadrant pain. [atsu.edu]

  A comprehensive list of symptoms includes the following: Pain in the chest and/or upper abdomen on the affected side, and/or shoulder Abdominal tenderness Abdominal swelling Nausea Vomiting Fever Chills Sweating Edema, especially of the abdomen and/or [diagnose-me.com]

• Weight Loss

  Abstract A 14-year-old girl had progressive dyspnea and right lower chest pain for about 1 1/2 months and a weight loss of 3 kg in 2 months. [ncbi.nlm.nih.gov]

  Images obtained through abdominal ultrasonography were helpful in making a preoperative diagnosis.A 52-year-old man was referred to the hospital because of progressive weight loss of 10 kg during the preceding six months, despite the presence of a good [nejm.org]

  The manifestations of a subphrenic abscess range from a severe acute illness to an insidious chronic process characterized by intermittent fever, weight loss, anemia, and nonspecific symptoms. [pjmhsonline.com]

  Nausea, anorexia, and weight loss are common. Abscesses in the Douglas cul-de-sac, adjacent to the rectosigmoid junction, may cause diarrhea. [merckmanuals.com]

• High Fever

  Patients with peritonitis have a high risk of developing sepsis, and sepsis is related to symptoms like high fever, hypotension, tachycardia, tachypnea, impairment of renal function and eventually shock and multiple organ failure. [symptoma.com]

  A high fever is present in the initial stages but in severe peritonitis there may be hypothermia. Tachycardia is usually present. The classic abdominal signs are tenderness on palpation, guarding and rebound tenderness. [patient.info]

  PID also typically presents with a high fever, unlike the low grade fever in this case. Urinary tract infection (UTI) may present with urinary frequency and dysuria (cystitis) or loin pain and fever (pyelonephritis). [studyingmed.com]

• Fatigue

  Patients can develop symptoms like tenderness and pressure in the abdomen, fever, restlessness, nausea, fatigue, and a feeling of general malaise. [wisegeek.com]

  The most typical of the prolonged fever, chills, poor sleep and appetite, fatigue, depression mentality. Patient takes a semi-sitting position enforced. Gentle breath. [survinat.com]

• Pleural Effusion

  Abstract The computed tomographic scans of 38 patients with proven subphrenic abscesses and 28 patients with proven pleural effusions were reviewed without knowledge of the final diagnosis. [ncbi.nlm.nih.gov]

  The efficacy of doxycycline as a pleural sclerosing agent in malignant pleural effusion: a prospective study. Respirology 1996;l:69-72. ‎ [books.google.de]

  The efficacy of doxycycline as a pleural sclerosing agent in malignant pleural effusion: a prospective study. Respirology 1996;l:69-72. ‏ [books.google.com]

  Diagnosis Subphrenic Abscess: x Abdominal and chest radiographs: Usually show elevation of the diaphragm; may demonstrate basal lung consolidation and pleural effusion in some cases. ULTRASOUND PICTURES Subphrenic abscess. [ultrasound-cases.blogspot.com]

  He had right sided pleural effusion and raised, tented, right dome of diaphragm. After a pleural tapping his codition did not improve. A C.T. Scan confirmed the sub phrenic abscess. [medtube.net]

• Cough

  Presents with cough, increased respiratory rate with shallow respiration, diminished or absent breath sounds, hiccups, dullness in percussion, tenderness over the 8th–11th ribs, fever, chills, anorexia and shoulder tip pain on the affected side. [en.wikipedia.org]

  […] following: Pain in the chest and/or upper abdomen on the affected side, and/or shoulder Abdominal tenderness Abdominal swelling Nausea Vomiting Fever Chills Sweating Edema, especially of the abdomen and/or lower legs Loss of appetite Non-productive cough [diagnose-me.com]

  There might be a dry cough due to an atelectasis in the lung of the affected side. Alternatively there may be a pleural effusion (fluid in the chest cavity) on that side. Upper abdominal pain on the affected side is common. [nethealthbook.com]

  Some or all of the following signs and symptoms may be present: • Fever; • Loss of appetite approximately one month after surgery; • Non-productive cough; • Abdominal pain (on the affected side); • Leukocytosis and lack of red blood cells (anemia) appear [webhealth.com]

• Dyspnea

  Eleven days after surgery, dyspnea and fever prompted a computed tomography scan, which revealed a large subphrenic abscess. The abscess resolved with percutaneous drainage and intravenous antibiotics. [ncbi.nlm.nih.gov]

  The depth of respirations may be restricted, causing dyspnea. Diagnosis Subphrenic Abscess: x Abdominal and chest radiographs: Usually show elevation of the diaphragm; may demonstrate basal lung consolidation and pleural effusion in some cases. [ultrasound-cases.blogspot.com]

  The latter manifests in form of abdominal pain, tenderness over the inferior ribs, hiccup, dyspnea and tachycardia and non-productive cough. Pneumonia may develop. Additionally, gastrointestinal disorders like ileus may be reported. [symptoma.com]

  Subphrenic abscesses may cause chest symptoms such as nonproductive cough, chest pain, dyspnea, hiccups, and shoulder pain. Rales, rhonchi, or a friction rub may be audible. [merckmanuals.com]

• Dry Cough

  cough and loss of appetite. [diagnose-me.com]

  There might be a dry cough due to an atelectasis in the lung of the affected side. Alternatively there may be a pleural effusion (fluid in the chest cavity) on that side. Upper abdominal pain on the affected side is common. [nethealthbook.com]

  At nek-ry patients dry cough and pains at deep breath (Troyanov's symptom) are observed. At survey of patients are noted forced semi-sitting-chee situation, pallor of integuments, sometimes a subikterichnost of scleras. [bigmed.info]

• Rales

  Rales, rhonchi, or a friction rub may be audible. Dullness to percussion and decreased breath sounds are typical when basilar atelectasis, pneumonia, or pleural effusion occurs. Generally, there is tenderness over the location of the abscess. [merckmanuals.com]

  Dyspnea, cough, chest and shoulder pain and dullness or rales over the lung base may be noted. Pelvic abscess. [atsu.edu]

• Abdominal Pain

  One patient was readmitted 11 days after laparoscopic cholecystectomy with severe upper abdominal pain and a false aneurysm of a branch of the right hepatic artery. [ncbi.nlm.nih.gov]

  Marx: Rosen’s Emergency Medicine: Concepts and Clinical Practice, 5th ed., Copyright © 2002 Mosby, Inc., p. 185:”Abdominal pain”. 7. [nethealthbook.com]

  […] year-old woman was admitted with a 3-day history of abdominal pain, nausea, vomiting and constipation. [ispub.com]

  There was no history of fever, chills, vomiting, or abdominal pain. There was a history of non-insulin-dependent diabetes. .. José L. Zambrana, M.D., Ph.D. Juan A. García-Gutiérrez, M.D. Felipe Díez, M.D., Ph.D. [nejm.org]

• Vomiting

  Generally patients are asymptomatic but non-specific symptoms such as abdominal pain, distension, nausea, vomiting and constipation can be presented. [ispub.com]

  There was no history of fever, chills, vomiting, or abdominal pain. There was a history of non-insulin-dependent diabetes. .. José L. Zambrana, M.D., Ph.D. Juan A. García-Gutiérrez, M.D. Felipe Díez, M.D., Ph.D. [nejm.org]

  Nausea and vomiting are common. There is usually tenderness in the epigastrium, but this is absent in early disease. Leukocytosis is present. [atsu.edu]

  There was no vomiting, diarrhea, or abdominal pain. There was no history of pica. Initially at physical examination his chest was clear, and a chest radiograph revealed bilateral hilar infiltrates. [pediatrics.aappublications.org]

• Nausea

  Generally patients are asymptomatic but non-specific symptoms such as abdominal pain, distension, nausea, vomiting and constipation can be presented. [ispub.com]

  Nausea and vomiting are common. There is usually tenderness in the epigastrium, but this is absent in early disease. Leukocytosis is present. [atsu.edu]

  Patients can develop symptoms like tenderness and pressure in the abdomen, fever, restlessness, nausea, fatigue, and a feeling of general malaise. [wisegeek.com]

  A comprehensive list of symptoms includes the following: Pain in the chest and/or upper abdomen on the affected side, and/or shoulder Abdominal tenderness Abdominal swelling Nausea Vomiting Fever Chills Sweating Edema, especially of the abdomen and/or [diagnose-me.com]

• Hiccup

  Presents with cough, increased respiratory rate with shallow respiration, diminished or absent breath sounds, hiccups, dullness in percussion, tenderness over the 8th–11th ribs, fever, chills, anorexia and shoulder tip pain on the affected side. [en.wikipedia.org]

  There are many complications of abscess including sepsis, pyrexia of unknown origin, abdominal pain, hiccups and chest pain but subphrenic abscess complicating pericarditis is a very rare condition shown by the very little research work done on it. [pjmhsonline.com]

  Subphrenic abscesses may cause chest symptoms such as nonproductive cough, chest pain, dyspnea, hiccups, and shoulder pain. Rales, rhonchi, or a friction rub may be audible. [merckmanuals.com]

  The latter manifests in form of abdominal pain, tenderness over the inferior ribs, hiccup, dyspnea and tachycardia and non-productive cough. Pneumonia may develop. Additionally, gastrointestinal disorders like ileus may be reported. [symptoma.com]

  With a subphrenic collection, there may be shoulder tip pain, hiccups and unexplained pulmonary symptoms (pleural effusion, basal atelectasis). [surgwiki.com]

• Loss of Appetite

  Symptoms can be very subtle and start perhaps with a fever and a loss of appetite approximately 1 month after the surgery. There might be a dry cough due to an atelectasis in the lung of the affected side. [nethealthbook.com]

  Some or all of the following signs and symptoms may be present: • Fever; • Loss of appetite approximately one month after surgery; • Non-productive cough; • Abdominal pain (on the affected side); • Leukocytosis and lack of red blood cells (anemia) appear [webhealth.com]

  With regards to the former, dyspnea, upper abdominal pain that aggravates if pressure is exerted over ribs eight to eleven, and non-specific symptoms like malaise, fever, chills and loss of appetite usually manifest before detrimental consequences set [symptoma.com]

  Differentials information This woman presents with abdominal pain associated with loss of appetite, which shifted to the right iliac fossa, and now has guarding and rigidity in that region. [studyingmed.com]

• Liver Mass

  The proximity of subphrenic inflammatory process to the pericardium overlying the left diaphragm may be a very key factor in determining whether pericardial complication develops 1 .With relatively little liver mass adherent to the left subphrenic surface [pjmhsonline.com]

• Chest Pain

  Abstract A 14-year-old girl had progressive dyspnea and right lower chest pain for about 1 1/2 months and a weight loss of 3 kg in 2 months. [ncbi.nlm.nih.gov]

  We report a 13 year old boy with Past History of Abdominal surgeries presenting with Right Upper quadrant pain, fever, chest pain and shortness of breath. [pjmhsonline.com]

  He reported the sudden onset of an acute chest pain with epigastric radiation 15 days before his hospital admission. [jmedicalcasereports.biomedcentral.com]

  Schubert S Chilaiditi’s syndrome: an unusual cause of chest or abdominal pain. Geriatrics 1998;53:85–8. 2. Matthews J, Beck GW, Bowley DM, Kingsnorth AN. [ispub.com]

• Shoulder Pain

  She has had moderate abdominal pain and mild left shoulder pain for 2 days Her hemoglobin concentration has ranged from 9.5 g”dL to 10 g/dL since the operation Current medications include hydrocodonie and docusate Her temperature is 39 1°C (102 4° [usmleforum.com]

  and left shoulder pain (referred from phrenic nerve irritation) Hematologic findings - due to decreased splenic clearance thrombocytosis Howell-Jolly bodies Please rate topic. [medbullets.com]

  Subphrenic abscesses may cause chest symptoms such as nonproductive cough, chest pain, dyspnea, hiccups, and shoulder pain. Rales, rhonchi, or a friction rub may be audible. [merckmanuals.com]

  Dyspnea, cough, chest and shoulder pain and dullness or rales over the lung base may be noted. Pelvic abscess. [atsu.edu]

  Symptoms may include fever, pain anywhere in the abdomen, diarrhoea or ileus. A subphrenic abscess can cause chest pain and also shoulder pain. Psoas muscle abscesses may lead to flank pain which radiates to the groin. [patient.info]

• Right Shoulder Pain

  Fever and right-upper-quadrant (RUQ) pain are the most common complaints. Pain is reported in as many as 80% of patients and may be associated with pleuritic chest pain or right shoulder pain. Symptoms are often misdiagnosed as acute cholecystitis. [es.slideshare.net]

• Suggestibility

  Our experience of these cases and a review of the literature suggest that the drainage catheters should be placed both internally and externally together into the abscess cavity. [ncbi.nlm.nih.gov]

  Right subphrenic collection is noted with cresenctric shape and thick enhancing peripheral wall suggesting relatively walled off subphrenic collection. [sumerdoc.blogspot.com]

  The absence of contrast leakage suggests that the perforation was sealed. A careful upper digestive tract endoscopy must be then performed to show the duodenal ulcer. [oatext.com]

  Accuracy of sonographic diagnosis Subphrenic Abscess: Sonography suggests the correct diagnosis, which is confirmed by ultrasound-guided needle aspiration. [ultrasound-cases.blogspot.com]

Laboratory analyses of blood samples are usually carried out but reveal only unspecific leukocytosis, anemia and possibly enhanced concentrations of alanine transaminase and aspartate transaminase. Blood cultures may confirm bacteremia and if Bacteroides spp. or Clostridium spp. can be identified, the patient is highly suspicious for an intra-abdominal abscess. However, in order to diagnose a SA, imaging techniques have to be applied. Whereas plain radiography and sonography are valuable options, computed tomography scans constitute the most sensitive and specific approach [2].

SA corresponds to sub-diaphragmatic local masses with soft-tissue density, but are usually not the only pathological findings. The hemidiaphragm covering the abscess may bulge into the thoracic cavity and does not often contribute to respiration. Pleural effusion is common and anomalies may also be noted in the lungs: Signs of pneumonia or a lung abscess may be observed. With regards to the abdominal cavity, gas may become visible within the abscess and thus outside of the gastrointestinal tract. The use of contrast agents may be indicated to detect a possible site of leakage or perforation.

• Atelectasis

  Abscesses near the diaphragm may result in chest x-ray abnormalities such as ipsilateral pleural effusion, elevated or immobile hemidiaphragm, lower lobe infiltrates, and atelectasis. CBC and blood cultures should be done. [merckmanuals.com]

  There might be a dry cough due to an atelectasis in the lung of the affected side. Alternatively there may be a pleural effusion (fluid in the chest cavity) on that side. Upper abdominal pain on the affected side is common. [nethealthbook.com]

  With a subphrenic collection, there may be shoulder tip pain, hiccups and unexplained pulmonary symptoms (pleural effusion, basal atelectasis). [surgwiki.com]

  In patients with subphrenic abscesses, irritation of contiguous structures may produce shoulder pain, hiccup, or unexplained pulmonary manifestations, such as pleural effusion, basal atelectasis, or pneumonia. [emedicine.medscape.com]

  It showed an atelectasis of the right lung base (Figures 1 and 2). The diagnosis of acute bronchopneumonia was made and our patient was given medical therapy with antibiotic (amoxicillin/clavulanic acid). [oatext.com]

• X-Ray Abnormal

  Abscesses near the diaphragm may result in chest x-ray abnormalities such as ipsilateral pleural effusion, elevated or immobile hemidiaphragm, lower lobe infiltrates, and atelectasis. CBC and blood cultures should be done. [merckmanuals.com]

• Chest X-Ray Abnormal

  Abscesses near the diaphragm may result in chest x-ray abnormalities such as ipsilateral pleural effusion, elevated or immobile hemidiaphragm, lower lobe infiltrates, and atelectasis. CBC and blood cultures should be done. [merckmanuals.com]

• Pleural Effusion

  Abstract The computed tomographic scans of 38 patients with proven subphrenic abscesses and 28 patients with proven pleural effusions were reviewed without knowledge of the final diagnosis. [ncbi.nlm.nih.gov]

  The efficacy of doxycycline as a pleural sclerosing agent in malignant pleural effusion: a prospective study. Respirology 1996;l:69-72. ‎ [books.google.de]

  The efficacy of doxycycline as a pleural sclerosing agent in malignant pleural effusion: a prospective study. Respirology 1996;l:69-72. ‏ [books.google.com]

  Diagnosis Subphrenic Abscess: x Abdominal and chest radiographs: Usually show elevation of the diaphragm; may demonstrate basal lung consolidation and pleural effusion in some cases. ULTRASOUND PICTURES Subphrenic abscess. [ultrasound-cases.blogspot.com]

  He had right sided pleural effusion and raised, tented, right dome of diaphragm. After a pleural tapping his codition did not improve. A C.T. Scan confirmed the sub phrenic abscess. [medtube.net]

• Pleural Exudate

  These pleural exudates may be caused by changes in the capillary permeability or lymph flow in the diaphragm induced by local effects of inflammatory products 2345. [pjmhsonline.com]

• Leukocytosis

  Blood tests (including CBC with white blood cell differential, erythrocyte sedimentation rate) show a leukocytosis and the patient may be anemic. Blood and/or urine cultures may show presence of specific bacteria. [diagnose-me.com]

  The course of the disease is indolent with hepatic enlargement, weight loss, marked leukocytosis and prostration. Subphrenic Abscess. Subphrenic abscess formation is usually an insidious process. [atsu.edu]

  In blood leukocytosis, accelerated ESR. [survinat.com]

  Blood tests show a leukocytosis, which means too many white blood cells. The test may also show a lack of red blood cells (anemia). First, plain abdominal X-ray films may show the abscess cavity with gas in it from gas producing bacteria. [nethealthbook.com]

  In addition, antibiotic administration may mask abdominal tenderness, fever, and leukocytosis. [emedicine.medscape.com]

SA has to be drained, and patients need to be treated with antibiotics prior to and after drainage. Percutaneous drainage is the method of choice if the abscess is easily accessible. However, other routes of access may be chosen, e.g. an endoscopic, transgastric approach has been described. Utmost care has to be taken not to contaminate the tract of the catheter. This may lead to complications like recurrent SA or abscess formation in adjacent tissues [9]. In fact, open surgery may be the better option if there is a high risk of such complications, or if the properties of pus don't allow its passage through a catheter. In general though, the risk of post-laparotomy complications is significantly higher than that of contamination during catheter drainage. Patients may benefit from regular instillation of fibrinolytics into catheters [10].

With respect to drug therapy, the selection of an adequate antimicrobial is often based on empiric evidence. Although bacterial culture may be ordered after SA drainage and obtainment of a usable specimen, it can't usually be afforded to delay medical treatment until results are available. According to epidemiological studies, the most common bacteria encountered in SA belong to the family of Enterobacteriaceae (e.g., Escherichia coli, Klebsiella spp., Proteus spp.), the genera of Bacteroides and Clostridium. The latter are obligate anaerobic bacteria. There is barely a single antibiotic effective against all these pathogens and in many cases, more than one compound is prescribed. Anti-anaerobic cephalosporins or combinations of aminoglycosides and metronidazole have been proven effective in preventing bacterial spread before and after surgery.

SA is a potentially life-threatening disease and the prognosis may be worsened by existing comorbidities. With regards to SA and its complications, a poor outcome is often related to multiple abscesses and/or abscess formation after emergency interventions, even though the latter have apparently been carried out successfully. Also, intractable and recurrent abscesses are considered unfavorable prognostic factors. In sum, even recent publications still report mortality rates from 11 to 31% [7].

The vast majority of SA develops after perforation of the stomach or intestines and/or secondary to abdominal surgery carried out to treat gastrointestinal disorders. Gastric or duodenal ulcer, acute appendicitis as well as diverticulitis predispose for spontaneous perforation and are common causes of SA [2] [3]. Furthermore, a common medical history of a SA patient consists of ulcer, appendicitis, or diverticulitis, apparently successful treatment of this condition, and onset of SA-associated symptoms months later [4]. Consistently, most abscesses contain a plethora of aerobic and anaerobic bacterial species that form part of the gastrointestinal flora. Of note, translocation of intestinal bacteria does not require perforation of the respective hollow organ. Disorders like mesenteric artery thrombosis and subsequent mesenteric ischemia may imply serious damage of the bowel wall and increase permeability without producing intestinal perforation.

Moreover, a variety of non-gastrointestinal primary diseases may also lead to the formation of a SA. For instance, thoracic foci of infection, namely pneumonia, lung abscess and pleural empyema, may spread to the abdominal cavity and trigger a purulent inflammation here. Besides, tuberculosis has been related to SA only in isolated cases [5]. With regards to abdominal organs, gall bladder, liver, spleen and pancreas may serve as sources of pathogens if they present an infection, presumably induced during surgery. The possibility of an osteomyelitis leading to secondary SA has been described, but has rarely been reported.

Bacteria may also be inoculated upon perforating trauma, either directly into the abdominal cavity or into adjacent tissues.

Available epidemiological data date from several decades ago. Then, retrospective studies revealed changing patterns in causative events and etiologic agents of SA. Although gastrointestinal and biliary diseases that required surgical intervention have long since been the main cause of SA, the precise entities that account for the majority have changed. For instance, appendicitis was the main disease underlying SA formation in the middle of the 20th century, while its relative importance decreased until the 1970s. In contrast, colon surgery gained importance and even surpassed that of appendicitis during that same period in time [6].

These epidemiological developments presumably continued into the present time. On the one hand, constant improvement of sanitary conditions in operating rooms reduces the incidence of post-operative infection. On the other hand, advances in diagnostics allow for an early recognition of gastrointestinal diseases and thus augment the rate of abdominal surgery. At this moment, it can only be speculated which effect determines the development of overall incidence rates

Abscess formation marks an advanced stage of bacterial infection and inflammation. Thus, SA cannot form without pathogens reaching the upper abdominal cavity. According to the above described causes of SA, this may happen during a surgical intervention, when bacteria are involuntarily inoculated into the abdominal cavity; or if an infection spreads from adjacent tissues; or as a consequence of bacteremia. However, these are not necessarily unidirectional developments and pathogens contained in an SA may use these same routes for metastatic spread. Consequently, affected individuals are at risk of inflammation and/or abscess formation in peritoneum, liver, spleen and diaphragm. In fact, such disorders are possible comorbidities in SA patients. And because SA may serve as a source of bacteria that may eventually cause peritonitis, septicemia and multiple organ failure, it is a potentially life-threatening disease. This detrimental chain of pathophysiological events may be induced by abscess rupture, which initially causes an extensive inflammatory reaction in the abdominal cavity. Subsequent edema formation and extravasation of proteins are often severe and may cause shock. If pathogens gain access to circulation, they may spread to distant organs, trigger local inflammation and eventually organ failure.

No specific measures can be recommended to prevent SA.

Subphrenic abscess (SA) refers to the presence of a pus-filled, usually well-demarcated cavity in the upper abdomen and is caused by diverse bacterial species. Pathogens that reach this part of the abdominal cavity induce a local inflammatory reaction and adhesions between parietal and visceral peritoneum and omentum develop rapidly. To a certain degree, the focus of infection can be contained by these processes. While they helps to reduce the likelihood of generalized peritonitis - a secondary event that cannot be prevented in any case -, it does facilitate the formation of a SA.

As has been indicated above, SA contains distinct species of aerobic and anaerobic bacteria originating from the gastrointestinal tract. In fact, the majority of SA is diagnosed in people that either suffered a perforation of stomach or intestines, or that underwent abdominal surgery. In the latter scenario, pathogens may also originate from the digestive system (e.g., from an anastomotic leak), or they may have been involuntarily inoculated into the abdominal cavity. However, the possibility of lungs, pleura, gall bladder, liver, spleen and pancreas being the source of infection should also be considered in SA patients.

Symptoms arise from local infection and functional impairment of the diaphragm, potentially from secondary peritonitis and imminent shock. With regards to the former, dyspnea, upper abdominal pain that aggravates if pressure is exerted over ribs eight to eleven, and non-specific symptoms like malaise, fever, chills and loss of appetite usually manifest before detrimental consequences set in.

A single SA may be located on either side of the body, inferior of the diaphragm, but multiple SA or SA combined with distant foci of infection have also been described [1]. The precise location of a SA may guide the search for a possible source, if the latter cannot be deduced from anamnestic data and physical examination. It has to be noted though that overlooking either causative or consequential comorbidities may significantly worsen the outcome.

Diagnostic imaging, namely computed tomography, is a sensitive and specific technique to diagnose SA. Administration of antibiotics and abscess drainage are the mainstays of SA therapy. If treatment is initiated before the infection spreads any further, and if comorbidities don't imply a poor outcome, prognosis is generally good.

In general, the medical term abscess refers to the formation of a pus-filled cavity in a previously undefined space. This also applies to subphrenic abscess (SA), i.e., an abscess that forms below the diaphragm.

Under physiological conditions, the abdominal cavity is sterile. For a SA to develop, bacteria have to reach the upper abdomen, and this may happen if stomach or intestines perforate or if a patient has to undergo abdominal surgery. With regards to the former, gastric or duodenal ulcer, acute appendicitis as well as diverticulitis predispose for spontaneous perforation and are common causes of SA. Although any laparotomy bears the risk of involuntary inoculation of pathogens, surgical interventions to treat gastrointestinal disorders are most likely to lead to SA formation.

The incidence of SA is low, i.e., few patients who suffer from any of the above mentioned diseases or who undergo surgery will develop such an abscess. However, SA is potentially life-threatening. They interfere with respiration and bowel movements, but they also constitute a permanent source of bacteria that may spread to adjacent or distant tissues. Such complications may lead to peritonitis, sepsis and death.

Treatment mainly consists in drainage (possibly percutaneous) and antibiotic therapy. If the initiation of therapy is not unnecessarily delayed, the outcome is generally good. It is thus of utmost importance to report post-operative complications to the treating physician.

1. Klos D, Orsag J, Lovecek M, et al. Emergency surgical treatment of complicated acute pancreatitis after kidney transplantation with acute rejection: Case report and literature review. Ann Med Surg (Lond). 2016; 8:14-17.
2. Camera L, Calabrese M, Romeo V, et al. Perforated duodenal ulcer presenting with a subphrenic abscess revealed by plain abdominal X-ray films and confirmed by multi-detector computed tomography: a case report. J Med Case Rep. 2013; 7:257.
3. Galván-Montano A, Flores-Nava G, Suárez-Roa Mde L, Salazar-Herrera MC, Lavalle-Villalobos A. Subhepatic appendicitis with subdiaphragmatic abscess in a pediatric patient without intestinal malrotation: case report. Cir Cir. 2010; 78(1):79-81.
4. Whalley HJ, Remoundos DD, Webster J, Silva MA. Shortness of breath, fever and abdominal pain in a 21-year-old student. BMJ Case Rep. 2013; 2013.
5. Solhpour A, Hajiabdolbaghi M, Jafari S, et al. Subphrenic abscess and recurring focal lesions due to tuberculosis in a patient with IgA deficiency. J Infect. 2007; 54(1):e9-12.
6. Wang SM, Wilson SE. Subphrenic abscess. The new epidemiology. Arch Surg. 1977; 112(8):934-936.
7. Mirpuri-Mirpuri PG, Alvarez-Cordoves MM, Perez-Monje A. [Subphrenic abscess in the context of low back pain and reading analytics in the primary care consultations]. Semergen. 2013; 39(4):236-239.
8. Okasha H, Mahmoud M. Treatment for resistant subphrenic abscess by combined intracavitary doxycycline and cyanoacrylate injection. J Adv Res. 2014; 5(3):409-411.
9. Yu A, Mindelzun RE, Jeffrey RB, Jr. Hepatic abscess following transhepatic drainage of subphrenic abscess. Abdom Imaging. 1999; 24(2):163-164.
10. Laborda A, De Gregorio MA, Miguelena JM, et al. Percutaneous treatment of intrabdominal abscess: urokinase versus saline serum in 100 cases using two surgical scoring systems in a randomized trial. Eur Radiol. 2009; 19(7):1772-1779.