Efficacy of functional hemodynamic parameters in predicting fluid responsiveness with pulse power analysis in surgical patients.

BACKGROUND: In this study we quantify the ability of dynamic cardiovascular parameters measured by the PulseCO™ algorithm of the LiDCO™plus monitor to predict the response to a fluid challenge in post-operative patients. METHODS: Surgical patients, admitted to the Intensive Care Unit from the operating theatre were monitored with the LiDCO™plus system. A number of static and dynamic cardiovascular measurements were recorded before and after a fluid challenge. Receiver Operator Characteristic (ROC) curve analysis was used to identify the baseline values, with optimum sensitivity and specificity, to predict responsiveness to a fluid challenge. RESULTS: Thirty-one patients were enrolled, and received protocol-based fluid challenges. Twelve (38%) responded by demonstrating an increase in stroke volume of >15%. Heart rate (HR) and central venous pressure (CVP) were not statistically different between responders and non-responders. Mean arterial pressure (mAP), systolic pressure variation (SPV), pulse pressure variation (PPV) and stroke volume variation (SVV) were statistically different between responders and non-responders. Parameters with a ROC area under the curve (AUC) significantly >0.5 included SPV 0.70 (0.52-0.88) P=0.046, PPV 0.87 (0.76-0.99) P<0.0002 and SVV 0.84 (0.71-0.96) P=0.0005. The best cut-off values (sensitivity and specificity) to predict fluid were SPV >9 mmHg (73%, 76%), PPV >13% (83%, 74%) and SVV >12.5% (75%, 83%). ROC analysis did not show the AUC to be significantly >0.5 for HR, mAP and CVP CONCLUSION: Dynamic indices measured by PulseCO™ (LiDCO) have a high sensitivity and specificity in predicting fluid responsiveness in sedated and mechanically ventilated patients. A cut-off value for PPV of 13% is the most sensitive and specific indicator of fluid responsiveness.

Progression of natural attenuation processes at a crude-oil spill site: I. Geochemical evolution of the plume.

A 16-year study of a hydrocarbon plume shows that the extent of contaminant migration and compound-specific behavior have changed as redox reactions, most notably iron reduction, have progressed over time. Concentration changes at a small scale, determined from analysis of pore-water samples drained from aquifer cores, are compared with concentration changes at the plume scale, determined from analysis of water samples from an observation well network. The small-scale data show clearly that the hydrocarbon plume is growing slowly as sediment iron oxides are depleted. Contaminants, such as ortho-xylene that appeared not to be moving downgradient from the oil on the basis of observation well data, are migrating in thin layers as the aquifer evolves to methanogenic conditions. However, the plume-scale observation well data show that the downgradient extent of the Fe2+ and BTEX plume did not change between 1992 and 1995. Instead, depletion of the unstable Fe (III) oxides near the subsurface crude-oil source has caused the maximum dissolved iron concentration zone within the plume to spread at a rate of approximately 3 m/year. The zone of maximum concentrations of benzene, toluene, ethylbenzene and xylene (BTEX) has also spread within the anoxic plume. In monitoring the remediation of hydrocarbon-contaminated ground water by natural attenuation, subtle concentration changes in observation well data from the anoxic zone may be diagnostic of depletion of the intrinsic electron-accepting capacity of the aquifer. Recognition of these subtle patterns may allow early prediction of growth of the hydrocarbon plume.

Progression of natural attenuation processes at a crude oil spill site: II. Controls on spatial distribution of microbial populations.

A multidisciplinary study of a crude-oil contaminated aquifer shows that the distribution of microbial physiologic types is strongly controlled by the aquifer properties and crude oil location. The microbial populations of four physiologic types were analyzed together with permeability, pore-water chemistry, nonaqueous oil content, and extractable sediment iron. Microbial data from three vertical profiles through the anaerobic portion of the contaminated aquifer clearly show areas that have progressed from iron-reduction to methanogenesis. These locations contain lower numbers of iron reducers, and increased numbers of fermenters with detectable methanogens. Methanogenic conditions exist both in the area contaminated by nonaqueous oil and also below the oil where high hydrocarbon concentrations correspond to local increases in aquifer permeability. The results indicate that high contaminant flux either from local dissolution or by advective transport plays a key role in determining which areas first become methanogenic. Other factors besides flux that are important include the sediment Fe(II) content and proximity to the water table. In locations near a seasonally oscillating water table, methanogenic conditions exist only below the lowest typical water table elevation. During 20 years since the oil spill occurred, a laterally continuous methanogenic zone has developed along a narrow horizon extending from the source area to 50-60 m downgradient. A companion paper [J. Contam. Hydrol. 53, 369-386] documents how the growth of the methanogenic zone results in expansion of the aquifer volume contaminated with the highest concentrations of benzene, toluene, ethylbenzene, and xylenes.

[Craniocerebral trauma from bullets: the correlation between computed tomography, the clinical picture, neurosurgical treatment and the long-term sequelae]. / Traumi cranio-encefalici da proiettile: correlazione tra Tomografia Computerizzata, clinica, trattamento neurochirurgico e sequele a distanza.

PURPOSE: To demonstrate the usefulness of CT findings in the planning of brain neurosurgery in gunshot victims, for prompt and successful treatment. MATERIAL AND METHODS: Thirty patients with brain gunshot wounds were examined with CT over 5 years. The patients were 27 men and 3 women whose mean age was 33 years (range: 17-56). Brain CT was carried out with thin (5-mm) slices and 10-mm gap; dynamic scanning (3-mm interscan time) was used especially in case of posterior fossa involvement and diffuse brain damage. The examination was integrated with cervical scout views to detect bullets in the neck and cervical dislocation. CT follow-up was carried out in 20 patients 24 hours postoperatively and every 6 hours in 9 patients in a severe postoperative coma. RESULTS: Twelve intracranial hematomas and 9 subdural hematomas, 3 of them bilateral, were treated and hemorrhage was resolved in 8 lacerocontusive foci. Skull plastic surgery was carried out in 5 cases. Surgical maneuvers were most difficult in the 5 crash bone injuries with wedged splinters; postoperative subarachnoid hemorrhage followed in 3 cases. Blood effusion in ventricles was drained in 6 cases; in 2 of them with permanent catheters. Eleven patients died: 4 right after surgery and 7 an average 15 days postoperatively. DISCUSSION AND CONCLUSIONS: In our series the mortality rate of firearm wounds of the skull base was 34% higher than that of the hemisphere; this is due to carotid hemorrhage and midbrain damage. Such traumas require emergency radiological diagnosis and neurosurgical treatment because of their severity and early irreversible complications. Complex operations and skilled surgeons may prevent disabling postoperative sequels. CT findings are indispensable and must be correctly interpreted. The radiologist and the neurosurgeon must collaborate closely and both must consider several diagnostic and prognostic factors affecting surgical planning.

[Suburban amebiasis: the diagnostic aspects via computed tomography and echography and the percutaneous treatment of amebic liver abscesses]. / Amebiasi sub-urbana: aspetti diagnostici con Tomografia Computerizzata ed ecografia e trattamento percutaneo degli ascessi amebici del fegato.

INTRODUCTION: Liver is the most common site of extraintestinal amebiasis and hepatic abscesses are the most frequent symptom, occurring in 3-9% of patients with amebic infection. Several studies have shown that drug treatment is more efficacious when combined with percutaneous drainage of the abscess, yielding quicker recovery and a positive body response. We report our US and CT findings in 16 patients with amebic abscesses, 12 of whom lived in a temperate peripheral area north-east of Naples. All patients had a clinical-diagnostic condition that we called "suburban amebiasis". Finally we report our personal experience with the US-guided therapeutic drainage of amebic abscesses with repeated cavity washings, which is important for positive parasitology. MATERIAL AND METHODS: We retrospectively reviewed the findings of 16 patients (11 men and 5 women; age range 36-78 years; mean 52) with amebic abscesses of liver examined with US and CT. US with a 3.5 MHz transducer was the technique of choice in all patients. 94% of liver abscesses and some extraintestinal complications were easily shown with this technique. CT angiography was then performed to detail and clarify US findings. Abscesses over 4 cm in diameter were submitted to US-guided percutaneous treatment which permitted abscess drainage, the collection of material for parasitology and repeated cavity washings. RESULTS: US showed multiple liver abscesses in 12 patients, which were multiseptate and formed by multiple hypo-/hyperechoic microabscesses in 4 of them. Four non-European patients had a single abscess, which is typical of tropical endemic forms. CT showed the amebic abscesses as hypodense roundish masses with clear-cut outline most often localized in the right lobe in the 12 multiple cases. After percutaneous drainage 13/16 patients (81%) reported less pain in the right hypochondrium and had a lower temperature; their hospitalization was also shorter. DISCUSSION AND CONCLUSIONS: Combined US and CT assessment facilitated the diagnosis of amebiasis and its differentiation from pyogenic abscess and hepatoma. The combination of US-guided drainage and drug treatment provides better results than either treatment alone and quicker improvement of patient conditions, with fewer extraintestinal complications. Percutaneous drainage should be used in abscesses bigger than 4-5 cm, those with questionable clinical-laboratory findings and finally those failing to respond to drug treatment alone. Positive parasitology of abscess content is related to repeated cavity washings after percutaneous drainage, likely because peripheral layers are much richer in amebae.

[Defecography in rectal wall prolapse conditions]. / Defecografia nelle malattie parietali del retto da prolasso.

INTRODUCTION: Pelvic floor and rectal prolapse conditions have greatly benefitted by new imaging and instrumental diagnostic approaches, and especially defecography, for both pathophysiological interpretation and differential diagnosis. We investigated the efficacy of defecography in the assessment of rectal prolapse, and in particular the role of videoproctography in diagnosing such dynamic disorders. MATERIAL AND METHODS: We selected 224 patients with rectal prolapse from a series of 1,190 consecutive subjects with evacuation disturbances examined in the last 5 years with defecography combined with videoproctography. The patients were 176 women and 48 men ranging in age 32-79 years (mean: 48). Defecography was carried out with Mahieu's technique, but we changed the filter position slightly. Sixty-seven per cent of our patients had been submitted to sigmoidoscopy, but this examination does not usually show rectal intussusception. Occult blood test in feces and double contrast barium enema were carried out in 42% and 38% of cases, respectively, to exclude any organic conditions of colon. RESULTS: Mucosal prolapse was more frequent than intussusception (71% and 34%, respectively); rectal walls went out through the anus in 12 cases of anorectal intussusception and thus caused external rectal prolapse. Rectal prolapse was associated with other anorectal alterations, such as rectocele, perineal descent and puborectalis muscle syndrome, in 96 cases. DISCUSSION AND CONCLUSIONS: The dynamic changes of ampulla are well depicted by videoproctography, which showed anorectum normalization and spontaneous reduction of invagination after intussusception. Defecography exhibited good capabilities in showing rectal wall function abnormalities. Finally, some features of videoproctography such as low radiation dose, noninvasiveness and ease of execution, make the examination acceptable to patients with anorectal disorders and for the follow-up of rectal prolapse.

[Computerized tomography features of intestinal infarction: 56 surgically treated patients of which 5 with reversible mesenteric ischemia]. / Aspetti alla Tomografia Computerizzata dell'infarto intestinale: 56 pazienti sottoposti a intervento chirurgico di cui 5 con ischemia mesenterica reversibile.

PURPOSE: Bowel infarction is a rare and typical condition of the elderly; despite improvements in diagnostic imaging and vascular surgery, bowel infarction remains a major cause of acute abdomen, with mortality rates ranging 70-80%. Diagnosis is often late because clinical signs, laboratory data and radiologic findings are aspecific. We investigated radiographic and particularly CT patterns of intestinal infarction in 56 patients submitted to surgery within 12 hours of admission. We also report the CT findings of 5 of these patients who had reversible mesenteric ischemia. MATERIAL AND METHODS: We retrospectively reviewed 56 cases of bowel infarction. The patients were 29 men and 27 women ranging in age 46-84 years (mean: 63). All the patients were submitted to plain radiography of the abdomen in different projections; emergency CT was carried out with i.v. contrast agent injection. We considered the following CT patterns: dilatation of intestinal loops > 2.5-3 mm, wall thickening > 3-4 mm, intraperitoneal effusion, stuffing of mesenteric vessels with diameter > 3 mm, air-fluid levels. RESULTS: Patients in the 7th decade of life were most frequently affected (38 cases), with an overall mortality rate of 59% (33 deaths). Plain radiography showed distention of bowel loops with air-fluid levels in 91% of cases. CT proved to be an accurate technique with higher sensitivity than radiography in detecting mesenteric edema and hemorrhage (68%), abdominal and pelvic effusion (88%), parietal pneumatosis (9%), wall thickening (29%), intraportal gas (7%), and thrombosis of superior mesenteric artery (3.5%). CT patterns in the 5 patients with reversible intestinal ischemia were wall thickening (80%), peritoneal effusion (80%), meteoric dilatatation (40%), a blurred appearance of mesenteric fat (40%). CONCLUSIONS: Angiography is a valuable imaging and treatment technique permitting the diagnosis of vascular occlusion and the intraarterial infusion of vasodilators, but it can be carried out in emergency in few centers only. This makes conventional radiology, and particularly CT, the only tool providing useful information for early diagnosis and treatment of bowel infarction. CT is more sensitive than radiography and does not exhibit the limitations of angiography--i.e., invasiveness, radiation exposure and complex organization. Therefore CT can presently be considered the method of choice in patients with suspected bowel infarction.

[The topicality and use of the radiological exam in gunshot wounds of the limbs. An assessment of 132 cases]. / Attualità e impiego dell'esame radiologico nelle ferite da arma da fuoco degli arti. Valutazione di 132 casi.

INTRODUCTION: Gunshot wounds of limbs are frequent injuries especially in Western countries. They can be single or associated with other penetrating gunshot wounds, for instance to the chest, abdomen and skull. PURPOSE: We investigated the current role and usefulness of conventional radiography in the assessment of gunshot injuries to limbs because, despite major advances in diagnostic imaging, this method remains the examination of choice in this condition. We stress the valuable contribution of conventional radiography to detection of bone blow-out fractures, multifocal traumatic bone changes, bone and joint injuries, bullet retention, and finally subcutaneous emphysema. MATERIAL AND METHODS: We retrospectively reviewed 132 cases of firearm injuries of limbs submitted to radiography March 1996 to July 1999. All the patients were men ranging in age 17-66 years (mean: 35). Radiography followed a preliminary physical examination, and follow-ups were carried out in the following days after orthopedic reduction of bone fractures or surgery with metal osteosynthesis. Emergency CT was performed first when chest, abdomen, or skull were involved. RESULTS: The lower limbs were involved three times as much as the upper ones; the leg was most frequently involved (61%), followed by thigh (61%), forearm and hands (24%), and feet (15%). The right lower limb was wounded in 65% of cases, especially tibia (55 cases) and femur (46 cases). Spiral injuries to bone diaphysis were the most frequent ones, followed by mixed fractures caused by cortical bone sinking from bullet impact. Bullets were retained in 60% of cases; subcutaneous emphysema was found in 78% of cases and vascular injuries in 25 cases in relation to disarranged fractures. We observed 4 arteriovenous fistulas during 3 years' follow-up. DISCUSSION AND CONCLUSIONS: Gunshot wounds to the limbs need a different clinical, diagnostic and therapeutic approach than thoracoabdominal and skull injuries, which require immediate and quick diagnosis and emergency treatment. The cases with injury to a primary artery from open and splintered fractures require emergency surgical reconstruction with vascular anastomosis and reduction of compound fractures, to prevent necrosis and amputation. Conventional radiography does depict the bullet and its site, subcutaneous emphysema, blow-out fractures, and the location of bone splinters. This permits adequate emergency surgery and an efficacious orthopedic approach, as well as selection of the cases to be submitted to clinical monitoring.

[The role of computed tomography in gunshot lesions of the chest. The authors' personal experience]. / Ruolo della Tomografia Computerizzata nelle lesioni da arma da fuoco del torace. Esperienza personale.

PURPOSE: CT is a valuable tool in assessing thoracic gunshot wounds. CT is also the method of choice in emergency, because it permits rapid depiction of bullet damage to the chest and to other body districts. This in turn permits correct assessment of the main thoracic injuries, plus adequate and prompt planning of surgical treatment or support intensive care. We report on the role of CT in diagnosing the complex pleuropulmonary, cardiovascular and thoracic wall injuries caused by gunshot wounds, with their specific and acute signs which differ greatly from those of other types of chest trauma. MATERIAL AND METHODS: In the last 4 years, we observed 76 cases of gunshot injury, twenty-six of them involved the chest. The patients, 25 men and 1 woman (mean age: 32 years, range: 17-48), were all submitted to emergency CT with i.v. contrast agent injection and the CT-angiography technique. The reanimator was always present to monitor the patients' vital functions and shock state. CT of the chest was integrated with CT of the abdomen and pelvis in 4 cases and with CT of the skull in 3 cases, to detect associated bullet wounds if any. RESULTS: The most frequent CT finding was lung parenchyma tear and bruise (25 cases), followed by hemothorax (18 cases) and subcutaneous chest wall emphysema (9 cases). Pneumothorax was seen in 5 cases, associated with hemothorax in 6; rib injuries were found in 7 cases; pneumomediastinum was found in 4 cases and areas of pulmonary atelectasis in 3; the diaphragm was ruptured in 4 cases. CT showed spinal involvement in 11 patients, with injury of D3 and D5 in 4 and 3 cases, respectively; signs of interrupted spinal marrow were found in 7 cases. Damage from gunshot wounds was detected in the liver, spleen, skull and limbs in 3, 2, 3 and 10 cases, respectively. DISCUSSION AND CONCLUSIONS: Chest radiography shows major gunshot wound damage to the chest and lungs, except for heart injuries and minimal pneumothorax. When abdominal and skull injuries are associated, CT should be the method of choice because it permits prompt and panoramic assessment of the severity of pulmonary and extrathoracic damage. This results in prompt and targeted treatment, avoiding unnecessary delays which may damage the patient further.

[Severe obliteration of the urethral lumen after wall stent implantation. An unusual radiographic finding]. / Schwere Obliteration des Harnröhrenlumens nach Wall-Stent-Implantation. Eine ungewöhnliche radiographische Besonderheit.

The treatment of urethral stricture is still a challenge for urologists. Irrespective of the treatment employed, urethral stricture recurs in about 30% of all cases. In recent years, the wall stent, originally conceived for vascular surgery, has proved to be effective for the treatment of bulbar urethral strictures. The results are good, morbidity and complications occur only occasionally. In this paper, we described the case of a young patient who suffered from complete occlusion of the prosthesis 8 months after its implantation. The low age of the patient and the X-ray features of this case are unusual. The obstruction was successfully resolved by endoscopic resection. Follow-up after 14 months revealed a mild, short stenosis of the proximal tip.

[Computerized tomography of osteochondral diseases of the talus dome]. / La Tomografia Computerizzata nella valutazione delle malattie osteocondrali della cupola astragalica.

The definition "osteochondritis dissecans" of the talus improperly includes a variety of diseases involving the chondral surface of the talus dome and the relative subchondral bone. To investigate the CT diagnostic potentials in the study of these conditions, 35 patients complaining of a "painful ankle" were examined with plain radiography and axial and direct paracoronal CT over a 2-year period. Twelve patients were then examined with double contrast CT arthrography with air and iodated contrast agents. CT diagnostic accuracy was assessed evaluating the following parameters: the presence and extent of the subchondral bone fragment, the presence of residual bone fragment attachment at the lesion base or its intraarticular dislocation, the presence of subchondral bone cysts, of chondral surface lesions and, finally, of capsular and ligamentous damage. All the patients with CT findings of osteochondral conditions of the talus dome were submitted to arthroscopic examination/treatment and/or surgical arthrotomy. Baseline CT exams accurately depicted all the lesions, except for early (grade I) lesions. Moreover, the administration of intraarticular contrast agent (CT arthrography) increased the diagnostic accuracy in articular cartilage studies. Therefore, the authors believe baseline CT on the orthogonal planes to represent an effective tool for the staging of osteochondral talar lesions and for accurate treatment planning.

[Arthrography in the diagnosis and treatment of idiopathic adhesive capsulitis]. / L'artrografia nella diagnosi e nella terapia della capsulite adesiva idiopatica.

The painful shoulder--i.e., adhesive capsulitis--present two basic symptoms: painful and impaired motion. Clinics allow the diagnosis to be made, but treatment is difficult. In our opinion, shoulder arthrography is very useful to distinguish idiopathic from secondary capsulitis involving bones and joints: moreover, in the patients with adhesive capsulitis, arthrography is useful when removing adhesions by repeated forceful distensions of the joint capsule. January 1990 through December 1991, forty-five patients with adhesive capsulitis were studied with shoulder arthrography; 19 patients with primary adhesive capsulitis underwent forceful distension with lidocain and contrast medium and the intraarticular injection of 40 mg of triamcinolone enantate to eliminate local adhesions. Arthrographic brisement yielded good results: improved motion was observed in all patients, lasting 2 to 7 months. Forceful joint capsule distension is easy to perform and complication-free and yields valuable results; all of the above make the procedure advisable as a good alternative to surgery in primary adhesive capsulitis patients.

Rectocele in males: clinical, defecographic, and CT study of singular cases.

The authors report eight cases of rectocele in male subjects studied with defecography and computed tomography. The pocket is located between the prostatic apex and the urogenital diaphragm. The abnormality has clinical significance.