Time course of organ failure in patients with septic shock treated with hydrocortisone: results of the Corticus study.

INTRODUCTION: Corticosteroids have been proposed to decrease morbidity and mortality in patients with septic shock. An impact on morbidity should be anticipated to be earlier and more easily detected than the impact on mortality. METHODS: Prospective, randomized, double-blind, placebo-controlled study of 28-day mortality in patients with septic shock for <72 h who underwent a short high-dose ACTH test in 52 centers in 9 European countries. Patients received 11-day treatment with hydrocortisone or placebo. Organ dysfunction/failure was quantified by the use of the sequential organ failure assessment (SOFA) score. RESULTS: From March 2002 to November 2005, 499 patients were enrolled (hydrocortisone 251, placebo 248). Both groups presented a similar SOFA score at baseline (hydrocortisone 10.8 ± 3.2 vs. placebo 10.7 ± 3.1 points). There was no difference in 28-day mortality between the two treatment groups (hydrocortisone 34.3% vs. placebo 31.5%). There was a decrease in the SOFA score of hydrocortisone-treated patients from day 0 to day 7 compared to the placebo-treated patients (p = 0.0027), driven by an improvement in cardiovascular organ dysfunction/failure (p = 0.0005) and in liver failure (p < 0.0001) in the hydrocortisone-treated patients. CONCLUSION: Patients randomized to treatment with hydrocortisone demonstrated a faster decrease in total organ dysfunction/failure determined by the SOFA score, primarily driven by a faster improvement in cardiovascular organ dysfunction/failure. This organ dysfunction/failure improvement was not accompanied by a decreased mortality.

Adenoviral vector transfection into the pulmonary epithelium after cecal ligation and puncture in rats.

BACKGROUND: Adenoviral-targeted gene delivery to respiratory epithelium can augment production of specific proteins. Therefore, it may be valuable in treating the acute respiratory distress syndrome. The authors tested the hypothesis that adenoviral vector uptake after cecal ligation and double puncture in rats, an animal model of the acute respiratory distress syndrome, is higher than that observed in controls that did not undergo operation ("nonoperated") or those that underwent a sham operation ("sham-operated"). METHODS: Adenoviruses expressing green fluorescent protein or Lac-Z were delivered into the lungs of anesthetized rats via tracheal catheter. Animals were killed 24 or 48 h later. Histopathology and green fluorescent protein expression were examined using light of fluorescence microscopy. Cellular localization of Lac-Z was determined with electron microscopy or semithin sectioning. Viral receptor density and localization were determined using imunoblotting and immunohistochemistry. RESULTS: After cecal ligation and double puncture, rats were hypoxic and tachypneic. Alveoli were segmentally consolidated, contained proteinaceous debris and neutrophils, and had thickened septa. Administration of adenoviruses to rats that were sham-operated or underwent cecal ligation and double puncture resulted in high levels of marker protein expression in cells lining alveoli. Use of 3 x 10(11) plaque-forming units instead of 3 x 10(12) plaque-forming units resulted in similar levels of green fluorescent protein expression with negligible viral-mediated lymphocytic infiltration. Semithin section and electron microscopy revealed expression primarily localized to type II alveolar cells. Abundance of alpha(v)beta3 integrins and human coxsackie-adenovirus receptor (receptors that modulate viral attachment and internalization) was increased after cecal ligation and double puncture, predominantly in type II pneumocytes. CONCLUSIONS: Cecal ligation and double puncture induces histologic and functional changes consistent with the acute respiratory distress syndrome, increases surface expression of viral receptors, and enhances adenoviral-mediated gene transfer.

Compensatory hepatic regeneration after mild, but not fulminant, intraperitoneal sepsis in rats.

Sepsis is the leading cause of death in surgical intensive care units. Although both mild sepsis secondary to cecal ligation and single puncture (CLP) and fulminant, double puncture CLP (2CLP) may provoke hepatocyte death, we hypothesize that regeneration compensates for cell death after CLP but not 2CLP. In male Sprague-Dawley rats, hepatic necrosis, as determined by serum alpha-glutathione S-transferase (alpha-GST) levels, was significantly but equally elevated over time after both CLP and 2CLP. Apoptosis, evaluated using both terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and morphological examination, was minimal after both CLP and 2CLP. Regeneration, assayed by staining tissue for incorporation of exogenously administered bromodeoxyuridine, was present after CLP but not after 2CLP. To further substantiate impaired regeneration, steady-state levels of mRNAs encoding JunB, LRF-1, and cyclin D1 were determined. After 2CLP, the absence of JunB, LRF-1, and cyclin D1 mRNAs confirmed failed activation of the mitogen-activated protein kinase-linked proliferative pathway and progression through the cell cycle. Therefore, failed hepatocyte regeneration may be a manifestation of hepatic dysfunction in fulminant sepsis.

Postcardiopulmonary bypass hypoxemia: a prospective study on incidence, risk factors, and clinical significance.

OBJECTIVE: To evaluate the clinical significance of low arterial oxygen tension-inspired oxygen concentration (PaO2-FIO2) ratio, as a measure of hypoxemia, in the early period after cardiac surgery with cardiopulmonary bypass (CPB); and to evaluate the preoperative, intraoperative, and postoperative factors contributing to the development of hypoxemia within the first 24 hours after cardiac surgery with CPB. DESIGN: Prospective observational study. SETTING: University hospital. PARTICIPANTS: Patients who underwent elective or emergency cardiac surgery with CPB (n = 466). INTERVENTIONS: Preoperative clinical and laboratory data were recorded, as were intraoperative and postoperative data regarding the PaO2-FIO2 ratio, fluid and drug therapy, and chest radiograph. Data analysis evaluated hypoxemia as depicted by the PaO2-FIO2 ratios at 1, 6, and 12 hours after surgery. Thereafter, the effect of the PaO2-FIO2 ratios on time to extubation, lung injury, and length of hospital stay was evaluated. The risk factors were analyzed in 3 separate periods: preoperative, intraoperative, and postoperative. Univariate and multivariate analyses were performed on each period separately. All data were analyzed in 2 consecutive steps: univariate analysis and multivariate analysis. MEASUREMENTS AND MAIN RESULTS: PaO2-FIO2 ratios after CPB were significantly lower compared with baseline values. Six patients (1.32%) met the clinical criteria compatible with acute lung injury. All 6 patients had prompt recovery. Significant risk factors for hypoxemia were age, obesity, reduced cardiac function, previous myocardial infarction, emergency surgery, baseline chest radiograph with alveolar edema, high creatinine level, prolonged CPB time, decreased baseline PaO2-FIO2, use of dopamine after discontinuation of CPB, coronary artery bypass grafting, use of left internal mammary artery, higher pump flow requirement during CPB, increased level of hemoglobin or total protein content, persistent hypothermia 2 and 6 hours after surgery, requirement for reexploration, event requiring reintubation, and chest radiograph with alveolar edema 1 hour after surgery. Six hours after surgery, a lower PaO2-FIO2 ratio correlated significantly with time to extubation and lung injury. CONCLUSIONS: This study shows that despite improvements in the technique of CPB, hypoxemia depicted by low PaO2-FIO2 ratios is common in patients after CPB. It is short lived, however, and has minimal effect on the postoperative clinical course of these patients.

High oxygen concentration exacerbates cardiopulmonary bypass-induced lung injury.

OBJECTIVE: To investigate the effect of ventilation with 100% oxygen on lung injury associated with surgery involving cardiopulmonary bypass (CPB). DESIGN: A prospective randomized study. SETTING: University hospital. PARTICIPANTS: Thirty patients undergoing coronary artery bypass graft surgery with CPB. INTERVENTIONS: Patients were randomized to receive 100% oxygen (Oxygen group) or 50% oxygen (Air group) throughout surgery. During CPB, patients' lungs in the Air group were flushed with air and in the Oxygen group with 100% oxygen. MEASUREMENTS AND MAIN RESULTS: Lung injury was evaluated by arterial oxygen tension-inspired oxygen concentration (PaO2-FIO2) ratio and cytokine levels (tumor necrosis factor-alpha and interleukin-8) in blood and bronchoalveolar lavage fluid measured before and after CPB. The lowest PaO2-FIO2 value was observed after 40 minutes following the completion of CPB in both groups. PaO2-FIO2 values 6 hours after CPB were not different from baseline in the Air group but remained lower (359+/-63 mmHg and 298+/-78 mmHg; p = 0.013) in the Oxygen group. Blood cytokine levels rose during surgery in both groups. Bronchoalveolar lavage levels of interleukin-8 did not change, whereas tumor necrosis factor-alpha increased only in the Oxygen group (p = 0.035). CONCLUSIONS: A significant decrease of oxygenation was observed in the early post-CPB period in both groups of patients, with delay in recovery in patients treated with 100% oxygen. A larger increase of the proinflammatory cytokines was found in patients treated with 100% oxygen. High oxygen concentrations during surgery with CPB should be used only when specifically required.

The role of fiberoptic bronchoscopy in airway management of the critically ill patient.

Fiberoptic bronchoscopes (FOB) play a pivotal role in airway management in the operating room and critical care environments. This article examines the role of FOBs in modern airway management based on a review of recent literature and personal experience.

Cecal ligation and double puncture impairs heat shock protein 70 (HSP-70) expression in the lungs of rats.

Induction of the heat shock response may improve outcome from pathophysiological disturbances. This improvement is associated with and believed to result from expression of heat shock protein (HSP)-70. Therefore, we examined the temporal expression of HSP-70 in an animal model of acute respiratory distress syndrome (ARDS) secondary to fecal peritonitis. Specifically, we hypothesize that sepsis in rats impairs pulmonary HSP-70 expression. ARDS was induced in adolescent rats via cecal ligation and double puncture (2CLP). Sham-operated animals served as controls. Lung tissue was collected 0, 3, 6, 16, 24, and 48 h after 2CLP and sham operation. Northern blot hybridization analysis was performed to detect steady-state HSP-70 messenger ribonucleic (mRNA) levels. HSP-70 protein levels were determined via immunoblotting and immunohistochemistry. Mortality after 2CLP was 50% at 24 h and 75% at 48 h. Northern blot hybridization analysis revealed no significant change in steady-state HSP-70 mRNA levels in lung at any time after 2CLP. HSP-70 steady-state mRNA levels increased after sham operation and was higher than values in 2CLP at 6, 16, and 24 h. HSP-70 protein levels did not change over time in either group. Thus, the expression of HSP-70 does not change after 2CLP. Although lack of an increase in protein levels may be adaptive after sham operation, it is not appropriate after 2CLP. Therefore, failed HSP-70 expression represents a form of pulmonary epithelial dysfunction that may contribute to lung injury in sepsis.

Computer assisted physiologic monitoring and stability assessment in vascular surgical patients undergoing general anesthesia--preliminary data.

BACKGROUND: Physiologic monitors present an influx of numerical data that can be overwhelming to the clinician. We combined several parameters in an effort to reduce the amount of information that must be continuously monitored including oxyhemoglobin saturation by pulse oximetry, end-tidal CO2 concentration, arterial blood pressure, and heart rate into an integrated measure--the health stability magnitude (HSM). The HSM is computed for a predetermined basal period, the reference HSM (RHSM), and recalculated continuously for comparison with the baseline value. In this study we present the HSM concept and examine changes in the HSM during abdominal aortic aneurysm surgery. MATERIALS AND METHODS: After IRB approval, nine patients were studied. The anesthesiologist recorded all significant intra-operative events. Within a defined time interval, data were recorded and used to calculate a combined parameter, the HSM. The baseline or reference value of this index (RHSM) was calculated after the induction of anesthesia. Individual HSM values were repeatedly calculated for ten second periods after the RHSM value was established. A > 30% deviation of the HSM from the RHSM was considered significant. Deviations in the HSM were compared with events recorded by the anesthesiologist on a paper record and with the record from an electronic record-keeping system. The deviation observed between two consecutive HSMs, called dHSM, was plotted against HSM to construct a contour diagram of data from all patients to which individual cases could be compared. RESULTS: The plot showed that dHSM vs. HSM values were tightly clustered. The inner contour on the distribution plot contained 90% of values. Individual patient's time course, projected on this diagram, revealed deviations form "normal" physiology. Fifty-nine events led to > 30% deviations in the HSM; 27 were anticipated events and 32 were unanticipated. CONCLUSION: The correlation between HSM and dHSM depicts changes in multiple monitored parameters that can be viewed using a single graphical representation. Projection of individual cases on the contour diagram may help the clinician to distinguish relative intraoperative stability from important events. Data reduction in this manner may guide clinical decision-making in response to unanticipated or unrecognized events.

Systolic pressure variation in hemodynamic monitoring after severe blast injury.

Fluid management in patients following blast injury is a major challenge. Fluid overload can exacerbate pulmonary dysfunction, whereas suboptimal resuscitation may exacerbate tissue damage. In three patients, we compared three methods of assessing volume status: central venous (CVP) and pulmonary artery occlusion (PAOP) pressures, left ventricular end-diastolic area (LVEDA) as measured by transesophageal echocardiography, and systolic pressure variation (SPV) of arterial blood pressure. All three patients were mechanically ventilated with high airway pressures (positive end-expiratory pressure 13 to 15 cm H2O, pressure control ventilation of 25 to 34 cm H2O, and I:E 2:1). Central venous pressure and PAOP were elevated in two of the patients (CVP 14 and 18 mmHg, PAOP 25 and 17 mmHg), and were within normal limits in the third (CVP 5 mmHg, PAOP 6 mmHg). Transesophageal echocardiography was performed in two patients and suggested a diagnosis of hypovolemia (LVEDA 2.3 and 2.7 cm2, shortening fraction 52% and 40%). Systolic pressure variation was elevated in all three patients (15 mmHg, 15 mmHg, and 20 mmHg), with very prominent dDown (23, 40, and 30 mmHg) and negative dUp components, thus corroborating the diagnosis of hypovolemia. Thus, in patients who are mechanically ventilated with high airway pressures, SPV may be a helpful tool in the diagnosis of hypovolemia.

Blast lung injury from an explosion on a civilian bus.

OBJECTIVE: To assess clinical signs and management of primary blast lung injury (BLI) from explosions in an enclosed space and to propose a BLI severity scoring system. DESIGN: Retrospective analysis. PATIENTS: Fifteen patients with primary BLI resulting from explosions on two civilian buses in 1996. RESULTS: Ten patients were extremely hypoxemic on admission (PaO2 < 65 mm Hg with oxygen supplementation). Four patients remained severely hypoxemic (PaO2/fraction of inspired oxygen (FIO2) ratio of < 60 mm Hg) after mechanical ventilation was established and pneumothoraces were drained. Initial chest radiographs revealed bilateral lung opacities of various sizes in 12 patients (80%). Seven patients (47%) had bilateral pneumothoraces and two patients had a unilateral pneumothorax. Five (33%) had clinically significant bronchopleural fistulae. After clinical and laboratory data were collected, a BLI severity score was defined based on hypoxemia (PaO2/FIO2 ratio), chest radiographic abnormalities, and barotrauma. Severe BLI was defined as a PaO2/FIO2 ratio of < 60 mm Hg, bilateral lung infiltrates, and bronchopleural fistula; moderate BLI as a PaO2/FIO2 ratio of 60 to 200 mm Hg and diffuse (bilateral/unilateral) lung infiltrates with or without pneumothorax; and mild BLI as a PaO2/FIO2 ratio of > 200, localized lung infiltrates, and no pneumothorax. Five patients developed ARDS with Murray scores > 2.5. Respiratory management included positive pressure ventilation in the majority of the patients and unconventional methods (ie, high-frequency jet ventilation, independent lung ventilation, nitric oxide, and extracorporeal membrane oxygenation) in patients with severe BLI. Of the four patients who had severe BLI, three died. All six patients with moderate BLI survived, and four of five with mild BLI survived (one with head injury died). CONCLUSIONS: BLI can cause severe hypoxemia, which can be improved significantly with aggressive treatment. The lung damage may be accurately estimated in the early hours after injury. The BLI severity score may be helpful in determining patient management and prediction of final outcome.

Tension pneumoperitoneum after blast injury: dramatic improvement in ventilatory and hemodynamic parameters after surgical decompression.

Tension pneumoperitoneum is a known although rare complication of barotrauma, which can accompany blast injury. We report two patients who suffered from severe pulmonary blast injury, accompanied by tension pneumoperitoneum, and who were severely hypoxemic, hypercarbic, and in shock. After surgical decompression of their pneumoperitoneum, respiratory and hemodynamic functions improved dramatically. Several mechanisms to explain this improvement are suggested. In such cases the release of the tension pneumoperitoneum is mandatory, and laparotomy with delayed closure can be contemplated.

Helium versus oxygen for tracheal gas insufflation during mechanical ventilation.

OBJECTIVE: To evaluate and compare the effect of tracheal gas insufflation using two gases with different physical properties, helium and oxygen, as an adjunct to conventional mechanical ventilation in patients with respiratory failure. DESIGN: Prospective, intervention study. SETTING: General intensive care unit in a tertiary university medical center. PATIENTS: Seven sedated and paralyzed patients with respiratory failure of various etiologies. All patients were ventilated in the volume-control mode (tidal volume 5 to 7 mL/kg). Inclusion criteria were PaCO2 of > or =50 torr (> or =6.7 kPa), together with peak inspiratory pressure of > or =35 cm H2O and respiratory rate of > or =14 breaths/min. INTERVENTIONS: All patients were intubated with an endotracheal tube that had an additional lumen opening at its distal end, through which tracheal gas insufflation was administered. The tracheal gas insufflation was applied continuously throughout the respiratory cycle at three flow rates (2, 4, and 6 L/min) with two gases, oxygen and helium, while the ventilatory settings were maintained constant. MEASUREMENTS AND MAIN RESULTS: In addition to airway pressures and arterial blood gases, the relative efficacy of tracheal gas insufflation with each gas was estimated using a "coefficient of efficiency" (which we defined as the change in PaCO2/peak inspiratory pressure) compared with baseline measurements. Tracheal gas insufflation with both gases decreased PaCO2 significantly (p < .05) at all flow rates. This effect was accompanied by an increase in airway pressure with both gases (oxygen and helium). However, at flow rates of 6 L/min, tracheal gas insufflation with helium resulted in lower peak inspiratory pressure than with oxygen. Tracheal gas insufflation with helium was more effective (as estimated by the coefficient of efficiency) than with oxygen at all flow rates (p < .05). CONCLUSION: In volume-controlled, mechanically ventilated patients with respiratory failure, tracheal gas insufflation with helium might be suggested as an alternative to oxygen.

Cerebral protection using retrograde cerebral perfusion during hypothermic circulatory arrest.

BACKGROUND: Retrograde cerebral perfusion through the superior vena cava (SVC) has been proposed to protect the brain from ischaemic injury during profound hypothermic circulatory arrest (PHCA). Its contribution to cerebral protection is unclear. Furthermore, the addition of anaesthetic or vasodilating agents to the SVC perfusate to enhance brain protection, has never been described. METHODS: In three patients undergoing repair of the ascending aorta utilizing PHCA, the upper body was retrogradely perfused with cold (16 degrees C) blood through the SVC by the cardiopulmonary bypass pump. Electroencephalographic activity was monitored using a computerized electroencephalographic monitor (Cerebro Trac 2500, SRD). Perfusion pressure was measured at a port in the cannula connector. Etomidate or thiopentone was injected into the SVC perfusate to arrest reappearing electroencephalographic activity. Nitroglycerin or nitroprusside was injected into the perfusate to increase retrograde flow and maintain a constant perfusion pressure. RESULTS: During PHCA periods of up to 61 min, recurrent electroencephalographic activity was abolished by the retrograde administration of small boluses of etomidate (total 50 mg) or thiopentone (total 500 mg). Nitroprusside (100 micrograms) and nitroglycerin (2 micrograms.kg-1.min-1) increased retrograde flow from 220 to 550 and 660 ml.min-1, respectively, while maintaining perfusion pressure (25-26 mmHg). Recovery from anaesthesia and surgery was uneventful, with no adverse neurological sequelae. CONCLUSION: Injection of anaesthetic agents into the retrograde SVC perfusate during PHCA, can suppress reoccurring electroencephalographic activity and retrograde injection of vasodilators can facilitate an increase in perfusion. It is suggested that both may augment brain protection.

The effects of cardiac surgery on early and late pulmonary functions.

BACKGROUND: Impaired pulmonary functions are common in cardiac patients. Early and late effects of cardiac surgery on pulmonary function tests (PFTs) are presented. METHODS: Fifty patients undergoing cardiac surgery (coronary artery bypass grafting [CABG, 74%], valve replacement or valvuloplasty [20%] and combined procedures [6%]) were studied. Anginal and cardiac failure symptoms severity, and smoking history, were evaluated preoperatively. PFTs were studied and compared pre-, and 3 weeks and 3.5 months postoperatively. RESULTS: Pre- and postoperative PFTs were inversely related to severity of preoperative symptoms. Forced vital capacity (FVC) dropped from 98% of predicted preoperatively, to 63% (P < 0.00001) and 75% (P < 0.00001) 3 weeks and 3.5 months postoperatively, respectively. Expiratory volume in the first 1 s of forced expiration (FEV1.0) decreased from 95% to 61% (P < 0.00001) and 70% (P < 0.00001), respectively. Forced expiratory flow at 50% of vital capacity (FEF50) decreased from 85% to 56% (P < 0.00001) and 59% (P < 0.00001). Forced expiratory flow at 75% of vital capacity (FEF75) decreased from 77% to 47% and 47% (P < 0.00001). Peak expiratory flow rate (PEFR) declined from 101% to 66% (P < 0.00001) and 86% (P < 0.003). Maximal voluntary ventilation declined from 103% to 68% (P < 0.00001) and 77% (P < 0.00001). Only FVC (P < 0.0003), FEV1.0 (P < 0.02) and PEFR (P < 0.0001) partially recovered postoperatively. Smoking history did not affect perioperative PFTs. Pre-, but not postoperative FVC, FEV1.0, FEF50 and FEF75 were worse in valve than in CABG patients. CONCLUSIONS: Pulmonary functions deteriorate significantly for at least 3.5 months after cardiac surgery. Preoperative cardiac ischaemic and failure symptoms are inversely related to perioperative PFTs.

Positive end-expiratory pressure increases pulmonary venous vascular resistance in patients after coronary artery surgery.

OBJECTIVE: To investigate the effect of positive and-expiratory pressure (PEEP) on the longitudinal distribution of pulmonary vascular resistance in patients immediately after coronary artery bypass grafting. DESIGN: Prospective, intervention study. SETTING: Postcardiac surgery intensive care unit in a teaching institution. PATIENTS: Twenty patients after elective coronary artery bypass grafting. INTERVENTION: The effect of PEEP on pulmonary circulation, at four different levels (0, 5, 10, and 15 cm H2O), was analyzed in 20 patients. MEASUREMENTS AND MAIN RESULTS: Mean pulmonary arterial pressure, left atrial pressure, pulmonary artery occlusion pressure, and pulmonary capillary pressure were measured at each PEEP level. A model consisting of two resistances in series was used to analyze the effect of PEEP on the pulmonary circulation. The pulmonary vascular resistance for each area (arterial and venous) of the circulation was calculated. Pulmonary vascular resistance increased from 216 +/- 70 dyne.sec/cm5 at a PEEP of 0 cm H2O to 308 +/- 125 dyne.sec/cm5 at a PEEP of 15 cm H2O (p < .001). This increase, however, resulted solely from an increase in the resistance of the venous part of the pulmonary circulation from 66 +/- 29 to 134 +/- 69 dyne.sec/cm5 (p < .001), without any change in pulmonary arterial resistance. CONCLUSIONS: PEEP increases pulmonary vascular resistance solely by increasing pulmonary venous resistance. When applying PEEP, changes in pulmonary vascular resistance may impede the resorption of pulmonary edema fluid.

Patient data management systems in anaesthesia: an emerging technology.

The purpose of this review is to define the expectations of an on-line automatic patient data management system (PDMS) into anaesthesia work-stations in and around the operating room suite. These expectations are based on review of available information in the medical literature, and trials of several systems that are available commercially, three of them in a more detailed fashion (i.e. Informatics, Datex and North American Drager). The ideal PDMS should: -- communicate with and capture the information from different monitors, anaesthesia machines and electronic gadgets (e.g., infusion pumps) used in the operating room (OR), while presenting selected relevant values and trends on a screen. -- inform the anaesthetist of deviations from preselected limits of physiological and technical values. In the future, the system will hopefully be upgraded to include an algorithm-based decision support system. -- communicate with the hospital mainframe computer, and automatically transfer demographic data, laboratory and imaging results, and records obtained during preoperative consultations. -- at the end of each anaesthetic procedure, create an anaesthetic record with relevant data automatically collected by the system, as well as that which was entered manually by the physician during the procedure. A copy of this anaesthesia file must be kept on a computerized archive system. None of the systems so far evaluated fulfilled all our expectations. We have therefore adopted approach for the gradual introduction of such a system into our OR environment over the next two to five years, during which expected improvements may be incorporated to upgrade the system.