Pasteurella multocida is a gram-negative coccobacillus bacterium found as a commensal in the oropharynx of domestic animals such as cats and dogs and some farm animals. Soft tissue infections and occasionally bacteremia in immunocompromised patients with direct contact with animals are described. We report a 61 year old male with a history of scratches and close contact with domestic cats, with a septic shock originating from a pulmonary focus, requiring mechanical ventilation and vasopressors. Blood cultures disclosed the presence of Pasteurella multocida. He responded successfully to antimicrobials.

We report a 39-year-old male with an aneurysmal subarachnoid hemorrhage without hydrocephalus, in whom a right choroidal aneurysm was early excluded by endovascular coil insertion. Intracranial pressure (PIC) and cerebral oxygenation (PtiO2) sensors for neuromonitoring were installed due to a persistent comatose state. From the 3rd day, neuromonitoring became altered. CT angiography and cerebral angiography showed severe proximal and distal vasospasm (VE) of the middle (ACM) and anterior (ACA) right cerebral arteries. VE was treated with angioplasty and intravenous nimodipine. Forty eight hours later, despite hemodynamic maximization, neuromonitoring became altered again, mainly explained by a decrease in PtiO2 below 15 mmHg. A severe VE in ACM and right ACA was confirmed by angiography. Given the presence of an early and recurrent VE, which was associated with a decrease in cerebral oxygenation, internal carotid micro-catheters for continuous nimodipine infusion were installed. This therapy maintained a normal neuromonitoring for 15 days. During this period, attempts were done to decrease or discontinue the infusion, but the patient presented parallel falls of cerebral oxygenation or decreased cerebral perfusion observed with perfusion CT, interpreted as persistent VE. Finally, the infusion was stopped at day 15 without significant complication. We conclude that intra-arterial nimodipine continuous infusion in refractory VE can be useful and safe in selected patients. Multimodal neuromonitoring is essential.

Paraquat, a non-selective bipyridyl pesticide, is one of the leading causes of death from intoxication in many parts of Asia and America. It is the second most sold herbicide worldwide, being widely used in Chile. Its ingestion generates toxicity due to the release of superoxide radicals, mainly affecting kidneys, lungs and liver. There is no antidote available. We report a 31 years old male who ingested Paraquat for suicidal purposes. He developed an acute renal and hepatic failure and a rapidly progressive severe respiratory failure with images compatible with acute pulmonary fibrosis. No response to immunosuppressive treatment was observed. He died eight days after admission. The use of cyclophosphamide associated with glucocorticoids could lower risk of death the in these patients, although the pathophysiology of respiratory failure is still under study.

Metformin-associated lactic acidosis is a severe and infrequent adverse event. Early diagnosis is essential to start an early treatment, which often has favorable results. We report a 56 years old non-insulin-requiring type 2 diabetic female who developed a severe metabolic acidosis associated with metformin in relation to an acute renal failure secondary to infectious diarrhea. Early treatment with bicarbonate and continuous hemofiltration allowed a quick improvement of the patient. Metformin-associated lactic acidosis has an elevated mortality (50-80%) and has a specific and effective treatment. Therefore, the condition must be born in mind.

Background: Extracorporeal membrane oxygenation (ECMO) is used with increasing frequency in patients with respiratory and cardiac failure. The achievement of an adequate anticoagulation is critical to avoid patient and circuit complications. Aim: To assess the feasibility and safety of anticoagulation with bivalirudin, as an alternative to unfractionated heparin (UFH), in patient with ECMO. Material and Methods: Observational study, which included all patients receiving anticoagulation with bivalirudin during ECMO, according to a standardized protocol, between august 2015 to May 2016. Results: Bivalirudin was used in 13 out 70 patients connected to ECMO. Ten procedures were for cardiac support and three for respiratory support. Mortality was 43%. ECMO lasted 31 ± 31 days. The time of UFH use before changing to bivalirudin was 7 ± 7 days. The reasons to change to bivalirudin were inadequate levels of partial thromboplastin time (PTT) in nine patients, and heparin induced thrombocytopenia (HIT) in four patients. The time of bivalirudin use was 24 ± 33 days. Per patient, a mean of 2.7 ± 4 oxygenators were changed. These had a useful life of 11.4 and 19.1 days during UFH and bivalirudin use, respectively. The mean bivalirudin dose was 0.08 ± 0.04 mg/kg/h. There was no significant bleeding, thrombosis or circuit obstruction during its use. PTT levels (p < 0.01) and platelet count (p < 0.01) increased significantly after the start of bivalirudin use in patients with UHF resistance and HIT, respectively. Conclusions: Bivalirudin was a safe and efficient drug for anticoagulation during ECMO. It is important to have an alternative drug for anticoagulation in ECMO patients.

Diverticular disease of the small intestine is rare, especially when it is located in the jejunum. It is generally asymptomatic, but in some patients it may have complications such as acute diverticulitis with peritonitis, gastrointestinal bleeding or obstruction. In such cases, the recommended treatment is surgery. We report a 77-year-old patient with ileal Crohn’s disease with a long-standing inflammatory phenotype, who developed acute diverticulitis of the jejunum presenting a severe septic shock and secondary multiple-organ failure. It resolved with medical treatment and prolonged antibiotic therapy.

Background: Sepsis-induced acute kidney injury (AKI) is an early and frequent organ dysfunction, associated with increased mortality. Aim: To evaluate the impact of macrohemodynamic and microcirculatory changes on renal function and histology during an experimental model of intra-abdominal sepsis. Material and Methods: In 18 anaesthetized pigs, catheters were installed to measure hemodynamic parameters in the carotid, right renal and pulmonary arteries. After baseline assessment and stabilization, animals were randomly divided to receive and intra-abdominal infusion of autologous feces or saline. Animals were observed for 18 hours thereafter. Results: In all septic animals, serum lactate levels increased, but only eight developed AKI (66%). These animals had higher creatinine and interleukin-6 levels, lower inulin and para-aminohippurate clearance (decreased glomerular filtration and renal plasma flow), and a negative lactate uptake. Septic animals with AKI had lower values of mean end arterial pressure, renal blood flow and kidney perfusion pressure, with an associated increase in kidney oxygen extraction. No tubular necrosis was observed in kidney histology. Conclusions: The reduction in renal blood flow and renal perfusion pressure were the main mechanisms associated with AKI, but were not associated with necrosis. Probably other mechanisms, such as microcirculatory vasoconstriction and inflammation also contributes to AKI development.

Background: Critically ill patients in Intensive Care Units (ICUs) are exposed to multiple procedures and usually require complex treatment regimens. Many of them suffer from comorbidities and different complications such as organ failure, drug-drug interactions, and unusual therapeutic interventions that can produce significant pathophysiologic changes. For that reason, pharmacokinetics for several substances is different to what is described for healthy patients, complicating drug selection and drug dosage to achieve appropriate effects. Low doses may determine a reduction of drug effectiveness and overdoses leading to toxicity. The aim of this paper is to review the pharmacokinetic considerations that must be considered when treating acute ICU patients.

OBJETIVO: O objetivo deste estudo foi avaliar os efeitos da pressão expiratória final positiva no estiramento, recrutamento e recrutamento e desrecrutamento cíclico avaliados por tomografia computadorizada pulmonar em pacientes com lesão pulmonar aguda/síndrome do desconforto respiratório agudo. MÉTODOS: Trata-se de um estudo aberto, controlado, não randomizado, de intervenção, em pacientes com lesão pulmonar aguda/síndrome do desconforto respiratório agudo. Foram realizados cortes simples de tomografia computadorizada durante pausas inspiratórias e expiratórias com um volume corrente de 6 ml/kg e níveis de pressão expiratória final positiva de 5, 10, 15 e 20 cmH2O. Medimos as densidades do parênquima pulmonar em unidades Hounsfield e calculamos o recrutamento, recrutamento e desrecrutamento cíclico induzidos pela pressão expiratória final positiva, assim como o estiramento. RESULTADOS: O aumento dos níveis de pressão expiratória final positiva aumenta de forma consistente o recrutamento e o estiramento globais (p<0,01), o que se correlacionou de forma significante com a pressão de platô (r²=0,97; p<0,01). O aumento dos níveis de pressão expiratória final positiva aumentou sistematicamente a distensão alveolar em todo o eixo esternovertebral. CONCLUSÃO: A distensão alveolar é um efeito adverso da pressão expiratória final positiva que deve ser ponderado em qualquer paciente em relação ao seus potenciais benefícios no recrutamento. Em razão do número reduzido de pacientes, estes dados devem ser considerados como geradores de hipótese e não limitar a aplicação de valores elevados de pressão expiratória final positiva em pacientes com hipoxemia grave.

OBJECTIVE: The objective of this study was to assess the effects of positive end-expiratory pressure on recruitment, cyclic recruitment and derecruitment and strain in patients with acute lung injury and acute respiratory distress syndrome using lung computed tomography. METHODS: This is an open, controlled, non-randomized interventional study of ten patients with acute lung injury and acute respiratory distress syndrome. Using computed tomography, single, basal slices of the lung were obtained during inspiratory and expiratory pauses at a tidal volume of 6 ml/kg and a positive end-expiratory pressure of 5, 10, 15 and 20 cmH2O. The densities of the lung parenchyma were measured in Hounsfield units. The values for positive end-expiratory pressure-induced recruitment, cyclic recruitment and derecruitment and strain were then calculated. RESULTS: Increasing levels of positive end-expiratory pressure were correlated with increased recruitment and global strain (p < 0.01), which was significantly correlated with plateau pressure (r² = 0.97, p < 0.01). In addition, increasing levels of positive end-expiratory pressure systematically increased strain along the sternovertebral axis. CONCLUSION: While strain is an adverse effect of positive end-expiratory pressure, the decision use positive end-expiratory pressure with any patient should be balanced against the potential benefits of recruitment. Due to the small number of patients in this study, the present data should be treated as hypothesis generating and is not intended to limit the clinical application of a high level of positive end-expiratory pressure in patients with severe hypoxemia.

Background: To recognize the etiological agent responsible for severe acute respiratory failure (ARF) in patients in mechanical ventilation (MV) is important to determine their treatment and prognosis, and to avoid the excessive use of antibiotics. Mini bronchoalveolar lavage (mini BAL) is a blind, non bronschoscopic procedure, used to obtain samples from the lower respiratory tract from patients on mechanical ventilation (MV). Aim: To assess the feasibility, complications and preliminary results of mini BAL among patients with severe ARF on MV. Material and Methods: Prospective study in 17 patients with acute lung injury (ALI ) or acute respiratory distess syndrome (ARDS) on MV and with negative conventional microbiological studies. Mini BAL was performed using standardized protocols. Hemodynamic and respiratory parameters where measured before and after the procedure. Samples obtained were sent to quantitative cultures. Results: At baseline: APACHE II score of 22 ± 6,7, PaO2/FiO2 ratio was 176.6 ± 48.6 and the oxygenation index was 9.74 ± 3.78. All procedures were performed by an ICU resident. Thirty five percent of the procedures had positive cultures and no complications related to the procedures were reported. The procedure lasted an average of 12 minutes and the instilled and rescued volume were 60 ml and 19.6 ml, respectively. There were no significant differences between hemodynamic and respiratory variables before and after the procedure. Conclusions: Mini BAL is a safe, fast and easy technique for obtaining samples from the inferior airway in patients with ALI or ARDS on MV.

Background: Chilean medical schools curricula are focused on the acquisition of competencies. Tracheal intubation is considered a terminal competence. Aim: To evaluate the competencies related to airway management including tracheal intubation in undergraduate medical students. Material and Methods: Prospective observational study. Thirty medical students in the sixth year of a seven years undergraduate program (25.2% of the cohort) were randomly chosen and invited to participate in a simulated environment of elective tracheal intubation using a manikin. The students were assessed according to a checklist validated with the Delphi technique and a written self-assessment questionnaire. Results: Seventeen students (57%) accepted to participate, corresponding to 14.3% of the cohort. Tracheal intubation was achieved by 64%, with 60 seconds as the mean time of apnea. Less than half of the students checked the instruments, performed pre-oxygenation or evaluated the airway. Eighty-seven percent of the students said that the current curriculum offers them minimal competencies for airway management in a real clinical situation and all prefer simulated scenarios for the acquisition of clinical skills. Conclusions: The methodology currently used to teach tracheal intubation is not assuring the acquisition of the competencies to the students in this curriculum stage. More effective teaching methods are required, and the use of simulated scenarios can be a useful tool.

Background: CT pulmonary angiography is the diagnostic procedure of choice for non-massive pulmonary embolism. Aim: To assess the diagnostic yield for thromboembolic disease of CT pulmonary angiography and venography using a 64- slice multidetector tomography. Material and Methods: Prospective study of patients with a clinical suspicion of thromboembolic disease, subjected to CT pulmonary angiography and venography. The presence and location of pulmonary thromboembolism, of isolated or concomitant deep venous thrombosis and of other significant radiological findings, were registered. Results: A 64-MDCT scanner was performed to 893 patients and thromboembolic disease was demonstrated in 240. Pulmonary thromboembolism was diagnosed in 218 patients. It was concomitant with deep venous thrombosis in 79 patients (36%) and isolated in the rest. Thirty fve of the 218 patients with pulmonary thromboembolism had radiological evidence of right ventricular overload. Twenty two patients (10%) had an isolated deep venous thrombosis. In 65 patients with pulmonary thromboembolism (30%) a possibly new or old malignant lesion, was observed. Seventy one of 653 patients without evidence of thromboembolic disease had potentially pathological findings on CT. Conclusions: The combined use of CT pulmonary arteriography and venography using a 64 MDCT scanner increases the diagnostic yield of the procedure for thromboembolic disease. It also allows the diagnosis of other related conditions, specially malignant tumors.

Myocardial dysfunction appears in 25% of patients with severe sepsis and in 50% of patients with septic shock, even in the presence of hyper dynamic states. It is characterized by a reduction in left ventricle ejection fraction, that reverts at the seventh to tenth day of evolution. Right ventricular dysfunction and diastolic left ventricular dysfunction can also appear. There is no consensus if an increase in end diastolic volume is part of the syndrome. High troponin or brain natriuretic peptide levels are associated with myocardial dysfunction and a higher mortality. The pathogenesis of myocardial dysfunction is related to micro and macro circulatory changes, infammatory response, oxidative stress, intracellular calcium management disturbances, metabolic changes, autonomic dysfunction, activation of apoptosis, mitochondrial abnormalities and a derangement in catecholaminergic stimulation. Since there is no specifc treatment for myocardial dysfunction, its management requires an adequate multi systemic support to maintain perfusion pressures and systemic fows suffcient for the regional and global demands.