Key points
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Sepsis is a life-threatening event with a mortality risk ranging from 10 to 40%.
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Early patient recognition is a cornerstone of sepsis management.
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Total-body CT imaging plays a pivotal role in septic shock condition.
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CT hypoperfusion complex recognition may facilitate early diagnosis improving treatment planning in septic shock patients.
Introduction
Etiopathogenesis
Signs and symptoms
Signs and symptoms | Laboratory tests | Diagnostic Imaging | Therapeutic strategies |
---|---|---|---|
Complicated urinary tract infections | |||
Fever, dysuria, pollakiuria, stranguria, lower back pain | Blood culture, physicochemical urine examination, urine culture | Ultrasound, contrast-enhancement US (CEUS), or CT abdomen pelvis | Antibiotic therapy; nephrostomy (if hydronephrosis); evaluation of urinary device removal |
Severe pneumonia | |||
Fever, cough, dyspnoea | Blood cultures, respiratory secretion sampling (bronchoaspirate or bronchial lavage); urinary antigens for pneumococcus or legionella; swab for influenza virus identification (epidemic period) | Chest X-ray, thoracic ultrasound, or CT scan | Antibiotics, with or without antiviral therapy; possible drainage of pleural empyema |
Complicated skin and soft tissue infections (± osteomyelitis) | |||
Fever, erythema, pain, oedema, suppuration, or necrosis | Blood cultures and microbiological examination of biopsy samples | Soft tissue ultrasound + bone X-ray; soft tissue + bone CT scan; soft tissue + bone MRI (magnetic Resonance imaging) (osteomyelitis*) *MRI is often the most appropriate second study, as it is highly sensitive and can detect bone marrow changes within days of infection | Antibiotic therapy; surgical therapy evaluation; hyperbaric therapy evaluation |
Complicated intra-abdominal infections | |||
Fever, abdominal pain, signs of sepsis | Blood cultures and cultures from in situ drainage < 24 h | Abdominal ultrasound or CT scan | Antibiotic + antifungal therapy; surgical evaluation; interventional radiology evaluation |
Central nervous system infections | |||
Fever, altered state of consciousness, signs of meningeal irritation | Blood cultures and the chemical and microbiological examination of the liquor | Head CT | Antibiotic therapy, subdural empyema drainage, or liquor derivation (hydrocephalus) |
Central nervous system infections | |||
Fever, signs of sepsis/septic shock, local inflammation | Blood cultures and microbiological examinations of any secretions | CT scan or echocardiogram (depending on the type of infection, location, and severity) | Antibiotic + antifungal therapy; Evaluation of device removal |
Diagnosis
Quick sequential organ failure assessment (qSOFA) | Score | |
---|---|---|
Respiratory rate ≥ 22/min | 1 | |
Change in mental status | 1 | |
Systolic blood pressure ≤ 100 mmHg | 1 |
Diagnostic imaging
CT hypoperfusion complex
CT hypoperfusion complex | |||
---|---|---|---|
Type | Sign | Definition | Incidence rate in patient with severe hypoperfusion* |
Vascular signs | Flattening of the inferior vena cava | IVC flattening with anterior-posterior diameter < 9 mm in three consecutive segments, 20 mm above and below the renal veins and at the level of the perihepatic portion | 77–100% |
The halo sign | The presence of low-density fluid < 20 HU surrounding the IVC | 77.8% | |
Small calibre aorta | A small-calibre abdominal aorta with anterior–posterior diameter < 13 mm detected 20 mm above and below the renal arteries | 20–48% | |
Visceral sign | Shock bowel | Small bowel fluid-filled dilated loops with thickened walls (> 3 mm) due to oedema of the submucosa and increased mucosal enhancement relative to the psoas muscle | 40–70% |
Mucosal enhancement of the gallbladder | Mucosal enhancement, without thickened gallbladder walls | 33.3% | |
Parenchymal signs | Peripancreatic oedema and abnormal pancreatic enhancement (shock pancreas) | Abnormal post-contrast higher attenuation than to normal density values (20 HU greater than the liver and spleen) often with peripancreatic low-density fluid (< 20 HU) | > 44% |
Splenic hypoperfusion | Extremely decreased enhancement in contrast early CT phase | 11–29.6% | |
Abnormal liver enhancement | A reduction of hepatic enhancement (25 HU less than the spleen) | 4–11.1% | |
Abnormal renal enhancement | Increased and prolonged parenchymal enhancement | 55.6% | |
Abnormal adrenal hyperenhancement (adrenal stress) | Bilateral hyperenhancement of the adrenal gland | > 60% | |
Abnormal thyroid enhancement (shock thyroid) | Heterogeneous contrast hyperenhancement, similar to a multinodular gland, with the presence of low-density fluid surrounding the thyroid (5–10 HU) | Not detected | |
Other sign | Ascites | Fluid collects in peritoneal spaces | Not detected |