[Lethal portal venous gas after cardiopulmonary arrest]

Intrahepatic gas at postmortem computed tomography: forensic experience as a potential guide for in vivo trauma imaging

BACKGROUND

Until August 2004 there were 106 forensic cases examined with postmortem multislice computed tomography (MSCT) and magnetic resonance (MR) imaging before traditional autopsy within the Virtopsy project. Intrahepatic gas (IHG) was a frequent finding in postmortem MSCT examinations. The aim of this study was to investigate its cause and significance.

METHODS

There were 84 virtopsy cases retrospectively investigated concerning the occurrence, location, and volume of IHG in postmortem MSCT imaging (1.25 mm collimation, 1.25 mm thickness). We assessed and noted the occurrence of intestinal distention, putrefaction, and systemic gas embolisms and the cause of death, possible open trauma, possible artificial respiration, and the postmortem interval. We investigated the relations between the findings using the contingency table (chi2 test) and the comparison of the postmortem intervals in both groups was performed using the t test in 79 nonputrefied corpses.

RESULTS

IHG was found in 47 cases (59.5%). In five of the cases, the IHG was caused or influenced by putrefaction. Gas distribution within the liver of the remaining 42 cases was as follows: hepatic arteries in 21 cases, hepatic veins in 35 cases, and portal vein branches in 13 cases; among which combinations also occurred in 20 cases. The presence of IHG was strongly related to open trauma with systemic gas. Pulmonary barotrauma as occurring under artificial respiration or in drowning also caused IHG. Putrefaction did not seem to influence the occurrence of IHG until macroscopic signs of putrefaction were noticeable.

CONCLUSIONS

IHG is a frequent finding in traumatic causes of death and requires a systemic gas embolism. Exceptions are putrefied or burned corpses. Common clinical causes such as necrotic bowel diseases appear rarely as a cause of IHG in our forensic case material.

[Air in the portal venous system: radiologic differential diagnosis and etiology-specific treatment]

Portal venous air is a rare but potentially grave radiologic sign. The routine use of abdominal CT and ultrasound allows the detection of minimal amounts of portal air, often at an asymptomatic stage. The first diagnosis to consider by both frequency and gravity is intestinal necrosis which carries a 75% mortality. And yet there are also benign etiologies of portal venous air, usually asymptomatic, which do not require surgical intervention. The aim of this study is to describe the differential diagnosis of portal venous air and its clinical management.

Pneumatosis intestinalis and hepatic portal venous gas after CPR

Pneumatosis intestinalis and hepatic portal venous gas are usually associated with severe intra-abdominal pathologies. As diagnostic technologies advanced, a number of variant etiologies have been identified. We report 2 cases in which pneumatosis intestinalis and hepatic portal venous gas developed after prolonged cardiopulmonary resuscitation (CPR). The pathogenic mechanism was most probably bowel infarction caused by poor mesenteric perfusion during and after CPR. Limited cardiac output during prolonged resuscitation and severe vasoconstriction after large doses of epinephrine and vasopressors might both contribute to the compromised mesenteric perfusion. The risk seems especially high for old patients with severe atherosclerosis. Once it happens, the prognosis is extremely poor. In patients of cardiac arrests receiving prolonged CPR, catastrophic complications like this should be considered in the postresuscitation phase, especially those with multiple risk factors like old age, severe atherosclerosis, and use of large doses of vasoconstrictors.

Hepatic portal venous gas associated with poor outcome in out-of-hospital cardiac arrest patients

OBJECTIVES

To determine the incidence of sonographic hepatic portal venous gas (HPVG) and to clarify the relationship between the presence of HPVG and clinical outcomes in patients with out-of-hospital cardiac arrest (OHCA).

METHODS

From April 2002 to January 2003, patients with non-traumatic OHCA were prospectively enrolled in a tertiary medical centre in Taipei, Taiwan. Emergency abdominal sonography during resuscitation was performed to detect the presence of HPVG within the first 10 min on arrival of the emergency department (ED).

RESULTS

HPVG was detected in 16 (36%) of the 44 patients enrolled in this study. The patients with HPVG were older (P = 0.039), their cardiac arrest was witnessed less frequently (P = 0.01), they received more prolonged resuscitation (P = 0.008), and needed more accumulated doses of adrenaline (epinephrine) (P = 0.002). These patients had a considerably lower incidence of return of spontaneous circulation (ROSC) (P < 0.001), less survival to hospital admission (P < 0.001), less 24 h survival (P < 0.001) and less survival to discharge (P = 0.036). In a multiple regression analysis, HPVG was noted as an independent factor negatively associated with ROSC.

CONCLUSION

HPVG is not uncommon in patients receiving resuscitation for OHCA and is associated with poor outcome in these patients.

[Hepatic portal venous gas]

STUDY OBJECTIVE

Hepatic portal venous gas is a radiological symptom associated with a poor prognosis (75% to 90% mortality). The aim of this retrospective study was to report 7 cases observed over a 2-year period.

PATIENTS AND METHOD

From June 1997 to November 1999, hepatic portal venous gas was diagnosed in 6 patients by CT scan and in one patient by echosonography. It was not detected in any case by plain abdominal X-rays. Three patients had small bowel obstruction with necrosis, three had extensive superior mesenteric infarction and one had preperforative necrosis of the colon.

RESULTS

One patient with extensive intestinal infarction and a metastatic head and neck cancer was not operated. Two patients were operated, but the extensive mesenteric infarction was not amenable to surgical management. Three of the 7 patients died, while the other four patients survived after resection of the necrotic small intestine (n = 3) and left colectomy extended to the transverse colon (n = 1).

CONCLUSION

Hepatic portal venous gas was associated with intestinal necrosis in the seven cases of this series. The severity of portal venous gas is only correlated with the severity of the disease causing portal venous gas.