Monitoring lung impedance changes during long-term ventilator-induced lung injury ventilation using electrical impedance tomography.

OBJECTIVE: The target of this methodological evaluation was the feasibility of long-term monitoring of changes in lung conditions by time-difference electrical impedance tomography (tdEIT). In contrast to ventilation monitoring by tdEIT, the monitoring of end-expiratory (EELIC) or end-inspiratory (EILIC) lung impedance change always requires a reference measurement. APPROACH: To determine the stability of the used Pulmovista 500® EIT system, as a prerequisite it was initially secured on a resistive phantom for 50 h. By comparing the slopes of EELIC for the whole lung area up to 48 h from 36 pigs ventilated at six positive end-expiratory pressure (PEEP) levels from 0 to 18 cmH2O we found a good agreement (range of r 2 = 0.93-1.0) between absolute EIT (aEIT) and tdEIT values. This justified the usage of tdEIT with its superior local resolution compared to aEIT for long-term determination of EELIC. MAIN RESULTS: The EELIC was between -0.07 Ωm day-1 at PEEP 4 and -1.04 Ωm day-1 at PEEP 18 cmH2O. The complex local time pattern for EELIC was roughly quantified by the new parameter, centre of end-expiratory change (CoEEC), in equivalence to the established centre of ventilation (CoV). The ventrally located mean of the CoV was fairly constant in the range of 42%-46% of thorax diameter; however, on the contrary, the CoEEC shifted from about 40% to about 75% in the dorsal direction for PEEP levels of 14 and 18 cmH2O. SIGNIFICANCE: The observed shifts started earlier for higher PEEP levels. Changes of EELI could be precisely monitored over a period of 48 h by tdEIT on pigs.

Living without aprotinin: the results of a 5-year blood saving program in cardiac surgery.

BACKGROUND: After 20 years of regular use in cardiac surgery patients, aprotinin has recently been withdrawn from the market due to many concerns about its safety. For a number of reasons aprotinin has not been available in Italy since 1998. The present study presents an aprotinin-free treatment protocol applied at our institution during the last 5 years, and aims to verify the results of this protocol in terms of allogeneic blood product transfusions, postoperative blood loss and surgical re-exploration rate. METHODS: Retrospective study on 7988 consecutive patients who underwent cardiac surgery during the years 2003-2007. All the patients received specific hemostasis/coagulation management based on (a) routine use of tranexamic acid, (b) heparin dose-response monitoring, thromboelastography, platelet (PLT) function analysis in a select population of patients, and (c) use of fresh frozen plasma (FFP), PLTs, and desmopressin according to the hemostasis/coagulation profile. Data retrieved from the institutional database were quantity of packed red cells (PRCs), FFP, PLT transfusion rate, blood loss in the first 12 postoperative hours, and surgical re-exploration rate. RESULTS: PRCs were transfused in 40.4% of patients (with higher rates for selected high-risk subpopulations), FFP in 12.9% and PLTs in 2.6%. Surgical re-exploration rate was 3.7%. With respect to historical controls, a significant reduction of PRCs and FFP transfusions was obtained using closed circuits, point of care coagulation tests, and combination of the two. CONCLUSION: This aprotinin-free blood saving program is an effective strategy for allogeneic blood products transfusion containment.

Hyperhomocysteinemia, antithrombin consumption, and early venous graft closure in surgical coronary revascularization.

Hyperhomocysteinemia is a pathological condition that increases cardiovascular risk due to prothrombotic behaviour in the patient. This case report concerns a 61-year-old man undergoing surgical coronary revascularization for early thrombosis of the venous graft. The postoperative antithrombin activity was extremely low (33%), despite normal preoperative values (79%) and a short cardiopulmonary bypass. At a subsequent screening, the patient was diagnosed with hyperhomocysteinemia (18.4 mmol/L) due to a heterozygous C677T mutation of the enzyme methylenetetrahydrofolate reductase associated with a folate deficiency. Hyperhomocysteinemia and cardiac operation are both factors that induce increased thrombin formation, which may induce antithrombin consumption and a consequent thrombotic event. Further studies are needed to define hyperhomocysteinemia as an independent risk factor for thrombotic events after cardiac surgery.

[Tetanus. Physiopathology and intensive care treatment]. / Tetano. Fisiopatologia e trattamento in terapia intensiva.

BACKGROUND: Tetanus as a topic illness is underlined on the basis of the increased cases as well as the appearance of new populations at risk of infection. The tetanospasmins of mechanism action is stressed in order to evaluate the etiopathogenetic role of common therapies as well as the new ones. Ten cases of serious infection personally observed are analysed. METHODS: The case records of ten tetanus patients treated in our Intensive Care Unit between 1986 and 1997 have been retrospectively analysed. The prognosis correlated to the seriousness of the case. The most common clinical symptoms on admission were trismus and dysphagia (100% of patients). In 70% of cases, the illness was considered serious enough to warrant the use of neuro-muscular blockers and controlled ventilation. Among the complications observed pulmonary problems had the highest incidence (90%), followed by cardio-vascular ones (80%). Respiratory infections were the most frequently observed (9 patients). Autonomic dysfunction was a constant feature in patients with severe forms of the illness. RESULTS: The observed mortality rate was 30%. It was higher in males at the extremes of the age range. CONCLUSIONS: In the light of the survival results as well as the most recent literature data, guidelines for the approach of serious tetanic patients are outline. It is underlined that therapy effectiveness is higher when from being a symptom therapy it becomes an etiopathogenetic therapy.