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Biomedical subjects

O Chiara

Publications and source records attributed to O Chiara.

At least 19 recordsLinked to original sources

Treatment of critical bleeding in trauma patients.

AIM: Massive haemorrhage after trauma is a big challenge for care-givers, being a leading cause of early in-hospital mortality. Surgical bleeding may be easily controlled with several techniques. Otherwise, consumptive coagulopathy is often extremely difficult to stop. An adjunctive strategy to treat traumatic coagulopathic bleeding is recombinant activated factor VII (rFVIIa) (NovoSeven, Novo Nordisk A/S, Bagsvaerd, Denmark). METHODS: All major trauma victims haemodinamically unstable (systolic blood pressure < 90 mmHg or > 90 mmHg with massive infusions or vasopressors) admitted to the Emergency Department of the Niguarda Ca' Granda Hospital in Milan from October 2002 to September 2005 were reviewed. Mechanical bleeding was controlled with interventional techniques when indicated. Blood derivatives were administrated to maintain haemoglobin> 7 g/dL, INR < 1.5, fibrinogen > 1 and platelet count > 50 x 109. Off-label administration of rFVIIa was performed in the last year in any coagulopathic salvageable patient when all other strategies failed to control bleeding. RESULTS: Major trauma were 942, mean age 32.49+/-18.44 years, 94% blunt trauma, 25.13% haemodynamically unstable. Deaths occurred in 17.02% of cases before any procedure. Emergency invasive treatments were performed in 72.34% of cases. Infusions restored haemodynamic stability in 10.63% of patients. In average 9.4+/-4.1 units of red blood cells were transfused in unstable patients. rFVIIa (dosing 60-100 mg/kg) was administrated in 12 patients. Mortality occurred in 33.33% of cases. The principal cause of death was brain injury. A femoral artery thrombosis was observed in a mangled leg. No other adverse effects due to rFVIIa were documented. CONCLUSIONS: Off-label administration of rFVIIa was able to reverse life-threatening bleeding not manageable with standard strategies in our series of major trauma patients without systemic adverse effects.

Adolescent↗

Laparoscopic treatment of sigmoid diverticulitis: a retrospective review of 103 cases.

BACKGROUND: Laparoscopic treatment of sigmoid diverticulitis is commonly accepted in Hinchey cases I and II, whereas it is debated in the case of purulent peritonitis, and not indicated for fecal peritonitis. METHODS: A single-center experience of 103 patients treated for Hinchey I-III sigmoid diverticulitis was reviewed. One-stage laparoscopic resection and primary anastomosis constituted the planned procedure. Abscesses in patients with Hinchey IIa were drained percutaneously before surgery. Patients with Hinchey III underwent surgery in emergency. A four-trocar approach with left iliac fossa minilaparotomy was used. Fistulas were treated laparoscopically with Harmonic Scalpel dissection. RESULTS: Laparoscopic treatment was successfully completed for 100 patients. Intraoperative complications occurred in 2.9% of the cases. Postoperative procedure-related morbidity was 8%, occurring mainly in Hinchey I patients. A longer hospital stay was recorded among Hinchey IIb patients treated for colovescical fistula. No mortality was observed. CONCLUSIONS: Laparoscopic surgery for sigmoid diverticulitis in experienced hands can be a safe and effective gold standard procedure also for patients with fistula or purulent peritonitis.

Aged↗

Mesenteric and renal oxygen transport during hemorrhage and reperfusion: evaluation of optimal goals for resuscitation.

BACKGROUND: Changes in flow to the gut and the kidney during hemorrhage and resuscitation contribute to organ dysfunction and outcome. We evaluated regional and splanchnic oxygen (O2) flow distribution and calculated oxygen supply distribution during hemorrhage and reperfusion and compared them with global measures. METHODS: Seven anesthetized pigs were instrumented to evaluate global hemodynamics, visceral blood flow, and oxygen transport. Tonometric pH probes were positioned in the stomach and jejunum. Animals were bled to 45 mm Hg for 1 hour. Crystalloids and blood were infused during the following 2 hours to normalize blood pressure, heart rate, urine output, and hemo- globin. RESULTS: During hemorrhage, mesenteric flow and O2 consumption were significantly decreased, whereas systemic consumption remained normal. Renal flow was reduced, but renal O2 consumption remained normal. After resuscitation, despite normal hemodynamics, neither systemic, mesenteric, nor renal O2 delivery returned to baseline. Lactate remained significantly increased. Arterial pH, base excess, and gastric and jejunal pH were all decreased. CONCLUSION: During hemorrhage, the gut is more prone than other regions to O2 consumption supply dependency. After resuscitation, standard clinical parameters do not detect residual O2 debt. Lactate, arterial pH, base excess, and intramucosal gut pH are all markers of residual tissue hypoperfusion.

Acid-Base Equilibrium↗

Inhibition of CD11-CD18 complex prevents acute lung injury and reduces mortality after peritonitis in rabbits.

Acute lung injury is frequent after severe peritonitis. The aim of this study was to investigate whether inhibition of the adhesion molecule CD11-CD18 on polymorphonuclear leukocytes (PMNs) would have any beneficial effects on pulmonary function and mortality in an animal model reproducing these clinical conditions. Acute peritonitis was induced in 36 rabbits by intraperitoneal injection of zymosan (0.6 g/kg) suspended in mineral oil; 20 were pretreated with a murine-specific IgG2a anti-CD18 monoclonal antibody, 16 (controls) with nonspecific purified murine IgG (1 mg/kg). The animals were followed for 10 d, then killed for histologic examination of the lungs. Blood samples were taken on Days 0, 1, 3, 7, and 10 for red blood cell (RBC), white blood cell (WBC), and platelet counts, pH, PO(2), PCO(2), carbon dioxide content (HCO(3)(-)) measurements, and renal and liver tests. Treatment with the anti-CD18 monoclonal antibody reduced mortality by approximately 40% (p < 0.05). PO(2) was higher in these treated animals than in the control animals throughout the study (p < 0.05 on Day 1, 3, and 10). On Day 1 control animals had significant leukopenia, whereas anti-CD18-treated animals had a moderate increase of the number of circulating WBC compared with baseline values (p < 0.05 between groups). The lungs of the anti-CD18-treated animals showed minor signs of inflammation and PMN infiltration whereas controls had interstitial and intra-alveolar edema and a large number of granulocytes. Quantification of PMNs by morphometry showed that there were constantly less granulocytes in the lungs of the animals treated with the anti-CD18 antibody (p < 0.001). PMN infiltration correlated with the levels of PO(2) (p < 0.001). Lung tissue of anti-CD18-treated rabbits contained less malonyldialdehyde, a by-product of membrane lipid peroxidation by PMN oxygen radicals (950 +/- 120 versus 1,710 +/- 450 pM/mg of protein) and, conversely, more of the antioxidant alpha-tocopherol (136 +/- 22 versus 40 +/- 9 ng/mg of protein), than the control rabbits (p < 0.01). In this particular model of ARDS the monoclonal antibody against the CD11-CD18 complex had a beneficial effect, reducing PMN infiltration and oxygen radical release in the lungs, preventing alveolocapillary membrane damage, improving gas exchange and, finally, significantly reducing mortality.

Animals↗

[Hypertonic saline solutions in resuscitation in hemorrhagic shock. An experimental study].

The aim of the study was to evaluate the use of hypertonic solutions in restoring intravascular volume in a model of hemorrhagic shock. Eighteen pigs underwent general anesthesia and were instrumented with a carotid catheter to record mean arterial pressure (MAP), a pulmonary artery catheter for pulmonary arterial pressure (MPAP) and cardiac output (CO) monitoring and an electromagnetic flowmeter around the abdominal supraceliac aorta for aortic flow measurement (Vaor). Oxygen delivery (DO2) and oxygen consumption (VO2) data were calculated by standard formulas. The animals were hemorrhaged to a MAP of 45 mmHg, held for 1 hour. They were resuscitated during the following hour until the aortic flow regained its basal value, using three different solutions: normotonic saline (NS = NaCl 0.9%), hypertonic saline (HS = NaCl 7.5%), hypertonic saline added with dextran (HSDX = NaCl 7.5% + 6% dextran 70). An hour of autologous blood transfusion and a two hours follow-up concluded the experiment. Volumes infused were remarkably lower administering HS (13.70 +/- 1.44 ml/kg) and HSDX (9.11 +/- 1.20 ml/kg) compared to NS (90.32 +/- 24.83 ml/kg). MAP, CO and DO2 values resulted significantly higher in the HSDX animals, with lower MPAP levels. During the two hours follow-up only the animals reinfused with HSDX maintained hemodynamic and oxygen transport values at normal levels. We conclude that the administration of hypertonic saline solutions during hemorrhagic shock allows the saving of infusion volumes, thus diminishing the occurrence of interstitial edema formation. The adding of dextran to the solution prolongs the hemodynamic effects.

Animals↗

[Smooth-muscle-cell tumors of the gastroenteric tract. A review of cases].

Smooth muscle tumors of the gastrointestinal tract are difficult to evaluate and to stage. Twenty-four patients surgically treated during the last ten years have been evaluated using a TGM staging to identify the more rational criteria for the therapeutic choice. Six gastric leiomyomas, 1 ileal leiomyoma, 4 gastric leiomyosarcomas, 1 esophageal leiomyosarcoma, 4 ileal leiomyosarcomas, 2 rectal leiomyosarcomas and 6 gastric leiomyoblastomas were included. 62.5% of cases presented acute clinical features. Preoperative histological diagnosis was adequate in 29% of cases. We performed 7 excisions, 6 gastric subtotal resections, 3 total gastrectomies, 1 esophageal resection, 5 ileal resections, 2 rectal low anterior resection. Fourteen patients were staged I/II, 8 staged III and 2 staged IV. The overall median survival time was 27.5 months (56, 20 and 5 months concerning stage I/II, III and IV respectively; p < 0.01). In relation to T and G factors overall survival was statistically significant. TGM staging was highly significant to predict long-term survival. Radical surgical procedure was highly effective to guarantee long-term survival. Extended follow up is requested because recurrences after many years seem to be possible also with low histologic grade at first presentation.

Aged↗

[Open treatment in acute severe pancreatitis].

Technical procedures normally used for open packing in our Institute (ICU) are described. Results of this procedure, utilized in thirteen patients suffering from infected pancreatic necrosis and multiple organ failure are reported. The grade of pancreatitis severity has been studied in detail. At admission patients presented a mean Ranson score of 6 and the morphological alteration sec. Balthazar was D in six patients and E in seven. At least two organs were insufficient at the beginning of our observation and the mean number of insufficient organs was 4. The mean APACHE II score was 20. Necrosis was documented in all patients. They were all admitted to ICU and the mean time of treatment was 50 days. Daily debridement was performed and continuous lavage was later added to daily open review. Three patients died, one from local bleeding and two from respiratory insufficiency. No patient died of sepsis and no mortality was observed in the last six cases. According to the severity of Ranson score, APACHE II, the number of insufficient organs and TAC morphological alteration predicted mortality rate should have been 70-80%; on the contrary, it was 25%. In conclusion open packing seems to be the correct treatment for infected pancreatic necrosis, particularly when it is complicated by multiple organ dysfunction.

APACHE↗

Complement activation and polymorphonuclear neutrophil leukocyte elastase in sepsis. Correlation with severity of disease.

Complement activation is necessary for an adequate immune and inflammatory response to infections. Activation releases anaphylatoxins that cause vasodilation, increase vascular permeability, and trigger release of polymorphonuclear neutrophil leukocyte (PMN) lysosomal enzyme and oxygen radicals. Under normal circumstances, an orderly progression of such events has a beneficial antimicrobial effect. The same mechanism, however, when uncontrolled, may damage host tissues. To provide information about the clinical importance of such events in sepsis, different complement parameters (C3, C4, and the desarginated forms of C3a [C3a(des)-Arg] and C5a [C5a(des)-Arg]), PMN elastase, and malondialdehyde (a by-product of membrane peroxidation by oxygen radicals) were measured daily in 26 septic patients and correlated with two objectively assessed and previously validated severity scores (acute physiology and chronic health evaluation [APACHE II] and Sepsis Severity Score [SSS]). Nonsurvivors (n = 12) had significantly greater and longer lasting complement activation than that in survivors, as reflected by higher levels of catabolic peptides (C3a(des)-Arg) and lower levels of native proteins (C3 and C4). C3a(des)-Arg, C3, C4, and the C3a(des)-Arg-C3 ratio were correlated with Sepsis Severity Scores. Polymorphonuclear neutrophil leukocyte elastase levels were higher in nonsurvivors and were correlated with C3a(des)-Arg and the C3a(des)-Arg-C3 ratio. Malondialdehyde levels were significantly higher in all patients than in controls, without, however, any relationship to severity of disease or clinical outcome. Since the higher and more persistent the complement activation and polymorphonuclear neutrophil leukocyte stimulation, the worse the patient's prognosis, we conclude that these mechanisms may be important in the clinical development of sepsis.

Adult↗

Inhibition by methylprednisolone of leukocyte-induced pulmonary damage.

BACKGROUND AND METHODS: The purpose of this study was twofold: the development of a chronic model of leukocyte-mediated pulmonary injury and the evaluation of the protective effects of methylprednisolone. Rabbits were inoculated ip with zymosan. Blood gases and circulating leukocytes were evaluated. Survivors were killed on day 10 for microscopic studies and for the evaluation of lung lipid peroxidation through the by-product malondialdehyde. RESULTS: Intraperitoneal zymosan resulted in a marked decrease of Pao2 and circulating leukocytes, and increased cellularity of alveolar septa, interstitial edema, and increased lung malondialdehyde. Pulmonary damage was partially prevented when methylprednisolone was administered before zymosan inoculation, but not when methylprednisolone was given 24 hr later. CONCLUSIONS: The authors conclude that a local nonseptic inflammatory stimulus may provoke remote changes to the lungs and that methylprednisolone may counteract the process only if it is administered before or very early after the onset of inflammation.

Animals↗

Lipid peroxidation and lung ultrastructural changes in an experimental model of leukocyte-mediated pulmonary injury.

The aim of this study was to study ultrastructural changes and lipid peroxidation in rabbits lung after massive complement activation and leukocyte aggregation. A prolonged and massive leukocyte activation was induced by intraperitoneal inoculation of zymosan suspected in paraffin. Fifteen animals (group 3) were given 0.6 g/kg of zymosan, 22 animals (group 2) received 1 g/kg, and 11 rabbits (group 1) were treated with paraffin alone and served as controls. An acute mortality rate of 40% was observed in group 3 and of 68% in group 2. Surviving animals were studied for 10 days. In these animals a marked decrease in circulating granulocytes and a progressive decline in arterial PO2 were recorded (PO2 on day 10 in group 2 animals was 51.94 +/- 4.26, p less than 0.01). Microscopic and ultrastructural evaluation revealed sequestration of granulocytes in the pulmonary microvasculature. Studies of lung homogenates demonstrated increased levels of lipid peroxide derivative malondialdehyde (group 2 rabbits, 1624 +/- 638; group 1, 795 +/- 57 pm/mg pt, p less than .001) and decreased levels of the tissue antioxidant alpha-tocopherol. The results of this study are compatible with the hypothesis of leukocyte-mediated injury through production of oxygen radicals.

Animals↗

Role of hepatic histologic findings in the prognosis and treatment of bleeding esophageal varices.

In the period from 1976 to 1986, we performed 329 hepatic needle biopsies using a posterior extraperitoneal approach in patients with bleeding esophageal varices. The histologic findings subdivided according to a four-stage classification were correlated significantly with immediate survival. Specifically, 21 of 23 stage IV patients with severe degenerative and necrotic parenchymal lesions died after immediate emergency surgery, whereas 26 of 48 stage IV patients who did not undergo emergency surgery survived. Stage IV patients appeared unable to withstand major surgery. According to our data, histologic stage and Child's class are independent parameters, especially in emergency situations, since they quantify different aspects of functional liver failure. Therapeutic implications are presented based on cumulative analysis of histologic stages and Child's classes.

Biopsy, Needle↗

Early diagnosis of adult respiratory distress syndrome: an experimental model of complement-mediated pulmonary injury.

This article presents an experimental model of pulmonary injury resembling subclinical human adult respiratory distress syndrome (ARDS) mediated by leukocytes. The activation of complement was prolonged by an intraperitoneal injection of a suspension of zymosan in paraffin. The first step in the development of the disease was an accumulation of polymorphonuclear leukocytes in the lungs. No significant changes were observed on chest radiographs or computed tomograms and the pathophysiologic changes were only minimal in spite of the characteristic structural changes. The criteria currently used for the diagnosis of ARDS are not sensitive enough to detect the subclinical phase of the disease.

Animals↗

Hypermetabolic response after hypothermic cardiopulmonary bypass.

Sixteen patients undergoing hypothermic cardiopulmonary bypass for open heart surgery were studied prospectively. Oxygen consumption and CO2 production showed a marked increase during the first 6 h postoperatively. Consequently, the measured resting energy expenditure was markedly elevated compared to the predicted energy expenditure. This hypermetabolic response occurred simultaneously with maximum spontaneous rewarming after the end of surgical procedures. Ventricular function was low throughout the postoperative period, and no cardiac response to increased energy requirements was recorded. On the contrary, marked increases in arteriovenous oxygen and CO2 difference were observed during the period of highest resting energy expenditure. We conclude that the first hours after hypothermic cardiopulmonary bypass represent the period of highest risk for decompensation. The continuous monitoring of CO2 production is suggested as a useful clinical method to detect postoperative changes in metabolic rate.

Aged↗