Clinical evaluation of the need for carbapenems to treat community-acquired and healthcare-associated pneumonia.

Carbapenems have an overall broad antibacterial spectrum and should be protected against from the acquisition of drug resistance. The clinical advantages of carbapenem in cases of pneumonia have not been certified and the need for antipseudomonal antimicrobial agents to treat healthcare-associated pneumonia (HCAP) remains controversial. We introduced an antimicrobial stewardship program for carbapenem and tazobactam/piperacillin use and investigated the effects of this program on the clinical outcomes of 591 pneumonia cases that did not require intensive care unit management, mechanical ventilation or treatment with vasopressor agents [221 patients with community-acquired pneumonia (CAP) and 370 patients with HCAP]. Compared with the pre-intervention period, age, comorbidities and the severity and etiology of pneumonia did not differ during the intervention period. Carbapenems were rarely used during the intervention period in cases of pneumonia (CAP: 12% vs. 1%, HCAP: 13% vs. 1%), while antipseudomonal beta-lactam use was reduced from 33% to 8% among cases with HCAP. This reduction in the rate of carbapenem administration did not have an impact on the prognosis in the cases of CAP, and the in-hospital mortality was lower among the patients with HCAP during the intervention period (15% vs. 5%, p = 0.013). The causes of death in the cases of HCAP were not directly related to pneumonia during the intervention period. The current study shows that carbapenem use can be avoided in cases of CAP or HCAP that are not in a critical condition. The frequent use of antipseudomonal beta-lactams does not improve the clinical outcomes of HCAP.

[Spontaneous tension hemothorax due to rupture of a solitary fibrous tumor of the posterior mediastinum].

A 37-year-old man was transported by ambulance to our hospital due to abrupt chest pain. The pain began when he was practicing a combative-type sport. He denied any impact or blunt trauma. A chest radiograph revealed massive left pleural effusion with a mediastinal shift. Thoracentesis revealed a hemothorax;therefore, we performed an emergency thoracotomy. The intraoperative findings revealed a rupture of a posterior mediastinal tumor itself located between the descending aorta and the thoracic vertebra. After we identified the artery of Adamkiewicz that originates away from the tumor and evaluated the degree of tumor extension into the inter-vertebral foramen, we safely performed an elective tumor resection 1 month after the initial emergency operation. In patients with a hemothorax caused by rupture of the tumor itself, an elective tumor resection after detailed investigation should be considered if hemostasis can be achieved in the emergency thoracotomy.

Postmortem computed tomography findings as evidence of traffic accident-related fatal injury.

PURPOSE: Most traumatic deaths in Japan are due to nonpenetrating injuries, especially those that result from traffic accidents; however, the autopsy rate of traffic accident-related deaths is only about 5%. We investigated the diagnostic ability of postmortem computed tomography (PMCT) in cases of fatal trauma after traffic accidents. MATERIALS AND METHODS: Our subjects were 78 subjects (59 males, 19 females; mean age 50 years, range 15-87 years) who were brought to our institution in cardiopulmonary arrest on arrival after traffic accidents and died despite resuscitation attempts. PMCT findings of damage to the head, neck, thorax, abdomen, and pelvis were classified into three grades according to the Abbreviated Injury Scale (AIS) severity: A: 1 (minor), 2 (moderate); B: 3 (serious), 4 (severe), 5 (critical); C: 6 (maximum). RESULTS: The percentage ratio of A/B/C in 78 head injuries was 32/60/8, in 41 neck injuries 83/5/12, in 76 thorax injuries 5/38/57, in 76 abdominal injuries 70/24/7, and in 76 pelvic injuries 79/21/0, respectively. CONCLUSION: PMCT can detect or presume fatal trauma when diagnosing the cause of death after traffic accidents.

Postmortem computed tomography and magnetic resonance imaging in a case of terminal-stage small cell lung cancer: an experience of autopsy imaging in tumor-related death.

We report a case of terminal-stage small-cell lung cancer with multiple metastases in which postmortem computed tomography and magnetic resonance imaging (collectively called "autopsy imaging") were performed and correlated with conventional autopsy findings. In this case, autopsy imaging provided contemporaneous data that supported conventional autopsy findings. Autopsy imaging revealed the process of primary tumor growth, changes in metastatic lesions, and occurrences of new metastases in the terminal stage and made it easier to understand the clinical course of the patient. The usefulness of autopsy imaging after traumatic death, sudden death from natural causes, or congenital anomaly has been reported. Here, we attempted a preliminary study of its use in the detection of death due to tumor. Our results indicated that autopsy imaging provides useful information in cancer-related death and may be an alternative when conventional autopsy cannot be performed.

Enlarged mediastinal air cyst in a patient with bronchial diverticula localized in the left main bronchus: a case report with surgical and bronchoscopic findings.

BACKGROUND: A mediastinal air cyst is a rare computed tomography (CT) finding. Once the lesion is identified, it is difficult to diagnose and treat. Meanwhile, bronchial diverticula have been reported as a CT finding observed in certain pulmonary pathologic conditions. We encountered the case of an enlarged mediastinal air cyst accompanied with bronchial diverticula and upper lobe-dominant fibrous changes of the lung. CASE PRESENTATION: A 69-year-old man with a chronic cough who had regularly visited a chest physician for upper lobe-dominant pulmonary fibrosis was referred to our hospital for the examination of an enlarged mediastinal air cyst. Chest CT exhibited an air cyst (size, 30 mm) connected to the lumen of the left main bronchus (LMB) and multiple tiny outpouches only on the LMB. Flexible bronchoscopy showed bubbling from slits or indentations of the bronchial mucosa only in the LMB but not in the right main bronchus or lobar bronchus. For therapeutic diagnosis, we removed the air cyst. Based on clinical, surgical, and pathological findings, we diagnosed the air cyst as an enlarged bronchial diverticulum. CONCLUSIONS: This is the first case wherein bronchoscopic and surgical findings of bronchial diverticula and an enlarged bronchial diverticulum are reported. There are possible pathogenic mechanisms in cases of pulmonary disease that are attributable to enlargement of the bronchial diverticula.

Comparison between computed tomography (CT) and autopsy findings in cases of abdominal injury and disease.

We report 10 autopsy cases involving fatal pathological changes in abdominal organs, for which findings of computed tomography (CT) on admission or after death were compared with autopsy findings. Two of the cases were death due to natural causes and eight were death due to traffic accidents. From the findings at autopsy, the causes of death were considered to be rupture of an aortic aneurysm in one case, gastrointestinal bleeding due to gastric cancer in one case, retroperitoneal bleeding in two cases, laceration of the liver in three cases, and traumatic rupture of the small intestine in three cases. CT findings revealed ascites or retroperitoneal bleeding in eight cases. However, in the cases of small-intestinal rupture, CT findings on admission revealed no free air. Therefore, ascites on CT should be regarded as a useful indicator of blunt abdominal trauma. Hepatic portal venous gas, known to be a post-mortem change, was significantly evident on post-mortem CT in cases of traumatic liver or intestinal injury, and was also seen in cases where the period between the accident and CT examination was long.

Postmortem computed tomography for detecting causes of sudden death in infants and children: retrospective review of cases.

PURPOSE: The aim of this study was to investigate the usefulness of postmortem computed tomography (PMCT) in detecting causes of sudden death in infants and children. MATERIALS AND METHODS: Our subjects were 15 nontraumatically deceased patients (nine boys and six girls, ranging in age from 20 days after birth to 12 years old, mean age 1.6 years), who had been in a state of cardiopulmonary arrest on arrival at our hospital. PMCT was performed within 2 h after certification of death: head (15 cases), chest (11 cases), and abdomen (12 cases). Blood was collected from 11 of the patients at the time of cardiopulmonary resuscitation. An autopsy was conducted on two. RESULTS: PMCT did not show any traumatic changes indicating child abuse. It was difficult to presume the cause of death with PMCT alone, but the cause of death in 14 of 15 cases could be presumed by combining information from their medical history, clinical course before death, PMCT findings, laboratory data, and bacterial culture. The remaining subject was classified as cause unknown. CONCLUSION: The causes of sudden death in infants and children were detected at a high rate when we comprehensively investigated the PMCT and other examination findings.

Postmortem computed tomographic (PMCT) and postmortem magnetic resonance imaging (PMMRI) demonstration of fatal massive retroperitoneal hemorrhage caused by abdominal aortic aneurysm (AAA) rupture.

We report a case of fatal massive retroperitoneal hemorrhage caused by the rupture of an abdominal aortic aneurysm (AAA) in which postmortem computed tomography (PMCT) and postmortem magnetic resonance imaging (PMMRI) provided clear delineation. In this case, the autopsy imaging system using PMCT and PMMRI was useful as a screening method to determine the cause of death as AAA rupture and became a guide for the subsequent autopsy.

Hepatic Relaxation Times from Postmortem MR Imaging of Adult Humans.

PURPOSE: To measure T1 and T2 values of hepatic postmortem magnetic resonance (PMMR) imaging. MATERIALS AND METHODS: We performed hepatic PMMR imaging of 22 deceased adults (16 men, 6 women; mean age, 56.3 years) whose deaths were for reasons other than liver injury or disease at a mean of 27.7 hours after death. Before imaging, the bodies were kept in cold storage at 4°C (mean rectal temperature, 17.6°C). We measured T1 and T2 values in the liver at two sites (the anterior segment of the right lobe and the lateral segment of the left lobe). We also investigated the influence of the body temperature and postmortem interval on T1 and T2 values. RESULTS: In the anterior segment of the right lobe and the lateral segment of the left lobe, T1 values of PMMR imaging were 524 ± 112 ms and 472 ± 104 ms (mean ± standard deviation), respectively; while T2 values were 42 ± 6 ms and 43 ± 8 ms, respectively. T1 and T2 values did not differ significantly between the two sites (P ≧ 0.05). Regarding temperature, the T2 values of hepatic PMMR imaging were linearly correlated with the body temperature, but the T1 values were not. The T1 and T2 values of the two sites in the liver did not correlate with the postmortem interval. CONCLUSION: Reduction in body temperature after death is considered to induce T1 and T2 value changes in the liver on PMMR imaging.

Cardiovascular gas on non-traumatic postmortem computed tomography (PMCT): the influence of cardiopulmonary resuscitation.

PURPOSE: The purpose of this study was to investigate the causes of cardiovascular gas (CVG) detected on non-traumatic postmortem computed tomography (PMCT). MATERIALS AND METHODS: PMCT was performed on 247 subjects within two hours of non-traumatic death, including 228 patients who had undergone cardiopulmonary resuscitation (CPR) and 19 patients who had not. We evaluated the incidence and distribution of CVG in four areas of the heart, namely, 1) the upper course of the right atrium (UC-RA), 2) the right atrium, 3) the right ventricle, and 4) the left heart (left atrium, left ventricle, and aorta). RESULTS: CVG was observed in 163 (71%) of the 228 patients who underwent CPR. In those 163 patients, we detected CVG in the UC-RA (103 patients), right atrium (81 patients), right ventricle (94 patients), and left heart (5 patients). Nineteen patients who received no CPR showed no CVG. CONCLUSION: CVG on non-traumatic PMCT is mainly caused by CPR, which is characterized by venous catheterization that permits possible air inflow and by pneumatization of dissolved gas in the blood as a result of cardiac massage.

Postmortem magnetic resonance imaging (PMMRI) demonstration of reversible injury phase myocardium in a case of sudden death from acute coronary plaque change.

We report a case of sudden death from acute coronary plaque change in which postmortem magnetic resonance imaging (PMMRI) detected reversible injury phase myocardium. Postmortem computed tomography (PMCT) of the chest showed diffuse ground-glass attenuation (GGA) in both lungs, suggesting pulmonary edema due to cardiac pump failure. T2-weighted imaging (T2WI) of PMMRI delineated the left anterior descending coronary artery (LAD) territory as showing high signal intensity relative to the remaining myocardium. Therefore, we presumed the cause of death was myocardial infarction (MI) of the LAD territory. Autopsy showed acute plaque change in the LAD, however, there were no indications of MI. In this case, autopsy imaging using PMCT and PMMRI was useful as a guide for autopsy.

Pseudo-Hirschsprung's disease with rectal hypoganglionosis: an autopsied case of circulatory failure due to severe constipation.

We report a 21-year-old female patient who suddenly died of circulatory failure due to pressure from megacolon allied with pseudo-Hirschsprung's disease. Since 3 years before her death, she had exhibited the feeling of abdominal distention, which was diagnosed as constipation. However, her constipation did not respond well to the prescribed oral administration of laxatives and enemas. She was found dead at home in the morning, lying on her back. An autopsy revealed a decreased number of ganglion cells in the rectum, suggesting hypoganglionosis. In cases of intractable chronic constipation, careful investigation of the cause of such symptoms is important.

Possibility of visualization of gastrothorax based on unenhanced postmortem computed tomography/PMCT.

We present a fatal case of a gastrothorax due to an acute gastric volvulus resulting from a Bochdalek hernia. A 5-year-old boy without previous medical history was brought to our institution in a state of cardiopulmonary arrest and was subsequently pronounced dead. Postmortem computed tomography (PMCT) of the torso showed abdominal organs involving the lower section of the esophagus up to the entire stomach, the left side of the transverse colon, the entire spleen, and the tail of the pancreas herniated into the left thoracic cavity. The stomach was markedly expanded and a mesentero-axial (rotation along the short axis) volvulus was observed, displacing mediastinal structures to the right side and depressing the diaphragmatic contour. A PMCT of the thorax at the lung window setting revealed displacement of bilateral lungs. The bilateral lungs were severely atelectatic and congested. The PMCT findings mentioned above were consistent with the autopsy findings. PMCT can provide useful information for the diagnosis in cases we initially cannot predict any significant changes, for example, organ displacement.

Pericardial tear as a consequence of cardiopulmonary resuscitation (CPR) involving chest compression: a report of two postmortem cases of acute type A aortic dissection with hemopericardium.

We present two cases of a pericardial tear as a consequence of cardiopulmonary resuscitation involving chest compressions in fatal acute type A aortic dissection (AoD) with hemopericardium. For each case, postmortem computed tomography revealed a hematoma in the false lumen of the ascending aorta with a slight hemopericardium and a large left hemothorax, as well as focal pericardial dimpling and discontinuity around the left ventricle. At autopsy, we confirmed a convex lens-shape gaping pericardial tear at the left posterolateral site of the pericardium and a massive volume of bloody fluid in the left thoracic cavity. It has been hypothesized that the pericardium ruptured due to chest compressions during resuscitation in these cases of acute type A AoD with hemopericardium and that intrapericardial blood leakage through the pericardial tear resulted in a hemothorax.

Cerebral relaxation times from postmortem MR imaging of adults.

PURPOSE: We measured T1 and T2 values of cerebral postmortem magnetic resonance (PMMR) imaging and compared the data of cadavers with that of living human subjects. MATERIALS AND METHODS: We performed PMMR imaging of the brains of 30 adults (22 men, 8 women; mean age, 58.2 years) whose deaths were for reasons other than brain injury or disease at a mean of 29.4 hours after death. Before imaging, the bodies were kept in cold storage at 4°C (mean rectal temperature, 15.6°C). We measured T1 and T2 values in the brain bilaterally at 5 sites (bilateral caudate nucleus, putamen, thalamus and gray matter and white matter of the frontal lobe) and compared the data of PMMR imaging with that from MR imaging of the corresponding sites in 24 healthy volunteers (9 men, 15 women; mean age, 51.8 years). We also investigated the influence of body temperature on T1 and T2 values. RESULTS: Compared with MR imaging findings in the living subjects, PMMR imaging showed significantly shorter T1 values in the caudate nucleus, putamen, thalamus and gray matter and white matter of the frontal lobe and significantly longer T2 values in the gray matter and white matter of the frontal lobe; T2 values in the caudate nucleus, putamen, and thalamus showed no such differences. T1 values correlated significantly with body temperature in all 5 brain sites measured, but T2 values did not. CONCLUSION: Compared with findings of cerebral MR imaging in living adult subjects, those of PMMR imaging tended to demonstrate shorter T1 values and longer T2 values. We attribute this to increased water content of tissue, reduced pH, and reduced body temperature after death.

Can ruptured abdominal aortic aneurysm be accurately diagnosed as the cause of death without postmortem computed tomography when autopsies cannot be performed?

PURPOSE: This study aimed to conduct a multicentre retrospective review of cases to clarify how many ruptured abdominal aortic aneurysms (RAAAs) as the cause of death could be diagnosed without post-mortem computed tomography (PMCT) when autopsies cannot be performed. METHODS: We collected consecutive PMCT data from January 2002 to December 2009 from three institutes where PMCT examinations are performed on a routine basis for deceased patients with unknown causes of death. A total of 19 cases were identified where PMCT revealed RAAAs. Ante-mortem clinical presentations, post-mortem external examinations, and peri-mortem ultrasonography findings were assessed for their diagnostic accuracy. RESULTS: The correct diagnosis based on the classic triad of shock, acute abdominal pain, and pulsatile abdominal mass was made in only one of 19 (5.3%) patients. Shock, acute abdominal pain, and abdominal swelling were found in five of 19 (26%) patients. Shock and acute abdominal pain or abdominal swelling were found in two of 19 (10%) patients. Ten of 19 (53%) patients only had shock. Peri-mortem ultrasonography was performed in seven of 19 patients; one was diagnosed with RAAA (14%). No patients had pre-mortem CT examinations. CONCLUSIONS: Post-mortem diagnosis of RAAA is difficult to make based on ante-mortem clinical presentation, post-mortem external examinations, or peri-mortem ultrasonography. PMCT is recommended for diagnosing RAAA as the cause of death if pre-mortem CT examinations are not carried out when autopsies cannot be performed.

Dialister pneumosintes bacteremia caused by dental caries and sinusitis.

A 62-year-old Japanese woman was hospitalized at the Department of Senology for positive signals on two sets of blood cultures obtained in the Emergency Department. The initial physical examination with enhanced computed tomography of the chest and abdomen did not identify the infectious source. Dialister pneumosintes was identified on 16S rRNA sequencing, and dental caries with sinusitis were subsequently diagnosed based on a dental examination and magnetic resonance imaging. History taking with respect to dental hygiene and oral examinations should be performed in daily clinical practice, especially in immunosuppressed patients.

Optimization of Inversion Time for Postmortem Fluid-attenuated Inversion Recovery (FLAIR) MR Imaging at 1.5T: Temperature-based Suppression of Cerebrospinal Fluid.

PURPOSE: Signal intensity (SI) and image contrast on postmortem magnetic resonance (MR) imaging are different from those of imaging of living bodies. We sought to suppress the SI of cerebrospinal fluid (CSF) sufficiently for fluid-attenuated inversion recovery (FLAIR) sequence in postmortem MR (PMMR) imaging by optimizing inversion time (TI). MATERIALS AND METHODS: We subject 28 deceased patients to PMMR imaging 3 to 113 hours after confirmation of death (mean, 27.4 hrs.). PMMR imaging was performed at 1.5 tesla, and T1 values of CSF were measured with maps of relaxation time. Rectal temperatures (RT) measured immediately after PMMR imaging ranged from 6 to 32°C (mean, 15.4°C). We analyzed the relationship between T1 and RT statistically using Pearson's correlation coefficient. We obtained FLAIR images from one cadaver using both a TI routinely used for living bodies and an optimized TI calculated from the RT. RESULTS: T1 values of CSF ranged from 2159 to 4063 ms (mean 2962.4), and there was a significantly positive correlation between T1 and RT (r = 0.96, P < 0.0001). The regression expression for the relationship was T1 = 74.4 * RT + 1813 for a magnetic field strength of 1.5T. The SI of CSF was effectively suppressed with the optimized TI (0.693 * T1), namely, TI = 0.693 * (77.4 * RT + 1813). CONCLUSION: Use of the TI calculated from the linear regression of the T1 and RT optimizes the FLAIR sequence of PMMR imaging.

Non-traumatic postmortem computed tomographic (PMCT) findings of the lung.

PURPOSE: We attempted to obtain postmortem computed tomographic (PMCT) images of the lung in cases of non-traumatic death and describe the results to distinguish usual postmortem findings from those of specific thoracic causes of death. MATERIALS AND METHODS: Our subjects were a total of 150 consecutive non-traumatic cases with cardiopulmonary arrest on arrival who were examined by CT within 2h after certification of death between January 1993 and December 2001. PMCT images of the lung and the frequency of imaging findings (dependent density, ground glass attenuation (GGA), consolidation, pleural effusion, and endotracheal (or endobronchial) air defect) were retrospectively reviewed. Autopsy had been conducted in 16 of the cases. RESULTS: The causes of death and frequency percentages of dependent density, GGA, consolidation, pleural effusion, and endotracheal (or endobronchial) air defect were: 91 cases of acute heart failure (AHF) (69, 66, 24, 11, 14%), 23 cases of aortic dissection (57, 39, 4, 52, 0%), 11 cases of pneumonia (18, 82, 100, 45, 27%), 23 other specified cases (52, 30, 13, 17, 9%), and two unspecified cases (0, 0, 0, 50, 0%), [total respective frequency percentages were (60, 57, 25, 21, 12%)]. Autopsy confirmed that GGA on PMCT in AHF cases corresponded to pulmonary edema. CONCLUSION: When PMCT of the lung shows no other shadows than dependent density, further analysis is necessary to detect the cause of death.