Osvaldo Chiara

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.

Resuscitation from hemorrhagic shock: Experimental model comparing normal saline, dextran, and hypertonic saline solutions

ObjectiveTo compare the effectiveness of normal saline, dextran, hypertonic, and hypertonic-hyperoncotic solutions in hemorrhagic shock. DesignLaboratory investigation. SettingUniversity hospital, Emergency Surgery and Intensive Care staff. SubjectsThirty-two large white female pigs. InterventionsRoutine care included: anesthesia and sedation (ketamine 10 mg/kg, droperidol 0.25 mg/kg, diazepam 0.7 mg/kg, fentanyl 0.006 mg/kg, 2% enflurane, 20% nitrous oxide, pancuronium bromide 0.13 mg/kg); volume-controlled ventilation (Paco2 35–40 torr; 4.7–5.4 kPa); cannulation of right carotid artery and pulmonary artery. Three flow probes (subdiaphragmatic aorta, superior mesenteric artery, right renal artery) and regional venous catheters (superior mesenteric vein, right renal vein) were positioned. Animals were bled to 45 mm Hg for 1 hr and resuscitated with four different fluids and blood to normal aortic blood flow and hemoglobin. Measurements and Main ResultsMean arterial pressure and blood flow through abdominal aorta (&OV0312;aor), mesenteric artery (&OV0312;mes), and renal artery (&OV0312;ren) were continuously monitored. Cardiac output, systemic and regional oxygen delivery (&U1E0A;o2, &U1E0A;o2mes, &U1E0A;o2ren), and consumption (&OV0312;o2, &OV0312;o2mes, &OV0312;o2ren) were recorded every 30 mins. Baseline &OV0312;aor was restored with different amounts of fluids in the four groups: normal saline (91.35 ± 22.18 mL/kg); dextran (16.24 ± 4.42 mL/kg); hypertonic (13.70 ± 1.44 mL/kg); and hypertonic-hyperoncotic (9.11 ± 1.20 mL/kg). The amount of sodium load was less using dextran and hypertonic-hyperoncotic and sodium levels were only transiently increased after hypertonic infusion. Mean arterial pressure and cardiac output were normalized in all groups. Animals resuscitated with normal saline and dextran showed increased pulmonary artery pressures. &U1E0A;o2 was significantly higher after hypertonic-hyperoncotic infusion, because of reduced hemodilution. Hypertonic and hypertonic-hyperoncotic normalized &OV0312;mes, &U1E0A;o2mes, &OV0312;o2mes, &OV0312;ren, and &U1E0A;o2ren, whereas normal saline and dextran did not achieve this result. At the end of the experiment, hypertonic-hyperoncotic maintained mean arterial pressure, cardiac output, and &U1E0A;o2 until the end of observation in contrast to normal saline, dextran, and hypertonic. ConclusionsResuscitation with a small volume of hypertonic-hyperoncotic solution allows systemic and splanchnic hemodynamic and oxygen transport recovery, without an increase in pulmonary artery pressure. It only transiently increased sodium concentration.

Trauma deaths in an Italian urban area: an audit of pre-hospital and in-hospital trauma care

In Italy, a comprehensive regional study of trauma deaths has never been performed. We examined the organization and delivery of trauma care in the city area of Milan, using panel review of trauma deaths. Two panels evaluated the appropriateness of care of all trauma victims occurred during 1 year, applying predefined criteria and judging deaths as not preventable (NP), possible preventable (PP), and definitely preventable (DP). Two hundred and fifty-five deaths were reviewed. Blunt trauma were 78.04% and motor vehicle crashes accounted for over 50%. Most victims (73.72%) died during pre-hospital settings and 91.1% died within the first 6h, principally because of central nervous system injuries in blunt and hemorrhage in penetrating trauma. Panels judged 57% of deaths NP, 32% PP, 11% DP (inter-panel K-test 0.88). Preventable deaths were higher after in-hospital admission. Main failures of treatment were lack in airway control or intravenous infusions in pre-hospital and mismanagement with missed injuries in emergency department. The high rate of avoidable deaths in Milan supports the need of trained pre-hospital personnel and of well equipped referring hospitals for trauma.

WSES Jerusalem guidelines for diagnosis and treatment of acute appendicitis

Acute appendicitis (AA) is among the most common cause of acute abdominal pain. Diagnosis of AA is challenging; a variable combination of clinical signs and symptoms has been used together with laboratory findings in several scoring systems proposed for suggesting the probability of AA and the possible subsequent management pathway. The role of imaging in the diagnosis of AA is still debated, with variable use of US, CT and MRI in different settings worldwide. Up to date, comprehensive clinical guidelines for diagnosis and management of AA have never been issued. In July 2015, during the 3rd World Congress of the WSES, held in Jerusalem (Israel), a panel of experts including an Organizational Committee and Scientific Committee and Scientific Secretariat, participated to a Consensus Conference where eight panelists presented a number of statements developed for each of the eight main questions about diagnosis and management of AA. The statements were then voted, eventually modified and finally approved by the participants to The Consensus Conference and lately by the board of co-authors. The current paper is reporting the definitive Guidelines Statements on each of the following topics: 1) Diagnostic efficiency of clinical scoring systems, 2) Role of Imaging, 3) Non-operative treatment for uncomplicated appendicitis, 4) Timing of appendectomy and in-hospital delay, 5) Surgical treatment 6) Scoring systems for intra-operative grading of appendicitis and their clinical usefulness 7) Non-surgical treatment for complicated appendicitis: abscess or phlegmon 8) Pre-operative and post-operative antibiotics.

The role of the open abdomen procedure in managing severe abdominal sepsis: WSES position paper

The open abdomen (OA) procedure is a significant surgical advance, as part of damage control techniques in severe abdominal trauma. Its application can be adapted to the advantage of patients with severe abdominal sepsis, however its precise role in these patients is still not clear.In severe abdominal sepsis the OA may allow early identification and draining of any residual infection, control any persistent source of infection, and remove more effectively infected or cytokine-loaded peritoneal fluid, preventing abdominal compartment syndrome and deferring definitive intervention and anastomosis until the patient is appropriately resuscitated and hemodynamically stable and thus better able to heal.However, the OA may require multiple returns to the operating room and may be associated with significant complications, including enteroatmospheric fistulas, loss of abdominal wall domain and large hernias.Surgeons should be aware of the pathophysiology of severe intra-abdominal sepsis and always keep in mind the option of using open abdomen to be able to use it in the right patient at the right time.

Organized trauma care: does volume matter and do trauma centers save lives?

Purpose of reviewTrauma is the leading cause of death during the first four decades of life. Since the 1970s, organized systems for trauma care, including a prehospital emergency medical system and a network of hospitals designated as trauma centers, have been developed. The model of the trauma system and its efficacy have been reviewed. Recent findingsFundamental to the trauma system is its recognition in the field and the transportation to a trauma center of patients with more serious injuries. Each trauma center has to treat at least 240 severe trauma patients per year to increase experience. It is cost-effective that less severely injured patients be treated in nontrauma centers acute care facilities, according to the inclusive system model. The effectiveness of trauma systems has been investigated by comparing postsystem with presystem trauma care with three methods: panel evaluation of preventable death rates, comparison of observed survival with expected probability of survival derived from large trauma registries, and evaluation of population-based general databases. These studies have demonstrated a decrease in preventable death rate and an increase in survival after system implementation. All these studies have been classified as providing weak class III evidence. However, with a large sample size and when properly designed, they generate important information regarding appropriateness of care delivered. SummaryConcentration of severely injured patients in trauma centers is associated with better outcomes. Population-based investigations provide the strongest evidence regarding effects of the trauma system on patient outcomes, other than survival outcome measures because long-term functional status may be more appropriate.

Preventable trauma deaths: from panel review to population based-studies.

Preventable trauma deaths are defined as deaths which could be avoided if optimal care has been delivered. Studies on preventable trauma deaths have been accomplished initially with panel reviews of pre-hospital and hospital charts. However, several investigators questioned the reliability and validity of this method because of low reproducibility of implicit judgments when they are made by different experts. Nevertheless, number of studies were published all around the world and ultimately gained some credibility, particularly in regions where comparisons were made before and after trauma system implementation with a resultant fall in mortality. During the last decade of century the method of comparing observed survival with probability of survival calculated from large trauma registries has obtained popularity. Preventable trauma deaths were identified as deaths occurred notwithstanding a high calculated probability of survival. In recent years, preventable trauma deaths studies have been replaced by population-based studies, which use databases representative of overall population, therefore with high epidemiologic value. These databases contain readily available information which carry out the advantage of objectivity and large numbers. Nowadays, population-based researches provide the strongest evidence regarding the effectiveness of trauma systems and trauma centers on patient outcomes.

World Society of Emergency Surgery (WSES) guidelines for management of skin and soft tissue infections

Skin and soft tissue infections (SSTIs) encompass a variety of pathological conditions ranging from simple superficial infections to severe necrotizing soft tissue infections. Necrotizing soft tissue infections (NSTIs) are potentially life-threatening infections of any layer of the soft tissue compartment associated with widespread necrosis and systemic toxicity. Successful management of NSTIs involves prompt recognition, timely surgical debridement or drainage, resuscitation and appropriate antibiotic therapy. A worldwide international panel of experts developed evidence-based guidelines for management of soft tissue infections. The multifaceted nature of these infections has led to a collaboration among surgeons, intensive care and infectious diseases specialists, who have shared these guidelines, implementing clinical practice recommendations.

The open abdomen, indications, management and definitive closure

The indications for Open Abdomen (OA) are generally all those situations in which is ongoing the development an intra-abdominal hypertension condition (IAH), in order to prevent the development of abdominal compartmental syndrome (ACS). In fact all those involved in care of a critically ill patient should in the first instance think how to prevent IAH and ACS. In case of ACS goal directed therapy to achieve early opening and early closure is the key: paradigm of closure shifts to combination of therapies including negative pressure wound therapy and dynamic closure, in order to reduce complications and avoid incisional hernia.There have been huge studies and progress in survival of critically ill trauma and septic surgical patients: this in part has been through the great work of pioneers, scientific societies and their guidelines; however future studies and continued innovation are needed to better understand optimal treatment strategies and to define more clearly the indications, because OA by itself is still a morbid procedure.

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.