Markos Kashiouris

Risk Factors for Development of Acute Kidney Injury in Critically Ill Patients: A Systematic Review and Meta-Analysis of Observational Studies

Background. Acute kidney injury (AKI) is a frequent complication of critically ill patients. The impact of different risk factors associated with this entity in the ICU setting is unknown. Objectives. The purpose of this research was to assess the risk factors associated with the development of AKI in critically ill patients by meta-analyses of observational studies. Data Extraction. Two reviewers independently and in duplicate used a standardized form to collect data from published reports. Authors were contacted for missing data. The Newcastle-Ottawa scale assessed study quality. Data Synthesis. Data from 31 diverse studies that enrolled 504,535 critically ill individuals from a wide variety of ICUs were included. Separate random-effects meta-analyses demonstrated a significantly increased risk of AKI with older age, diabetes, hypertension, higher baseline creatinine, heart failure, sepsis/systemic inflammatory response syndrome, use of nephrotoxic drugs, higher severity of disease scores, use of vasopressors/inotropes, high risk surgery, emergency surgery, use of intra-aortic balloon pump, and longer time in cardiopulmonary bypass pump. Conclusion. The best available evidence suggests an association of AKI with 13 different risk factors in subjects admitted to the ICU. Predictive models for identification of high risk individuals for developing AKI in all types of ICU are required.

Ventilator-Induced Lung Injury: Minimizing Its Impact in Patients With or at Risk for ARDS

Ventilator-induced lung injury (VILI) results from injury to the blood-gas barrier caused by mechanical ventilation. The determinants of VILI are more complex than originally thought, and include the nature, duration, and intensity of the exposure, as well the pattern of initial insult to the lung. Lung-protective mechanical ventilation founded on these basic principles resulted in improved hospital and long-term mortality. The purpose of this review is to provide a comprehensive assessment of the pathogenesis of VILI and its determinants. We also discuss the best preventive approach in patients with or at risk for ARDS and critically appraise the most recent evidence, expert opinion, and implementation of the acquired knowledge to the bedside.

Preliminary noise reduction efforts in a medical intensive care unit

Abstract Noise is a significant contributor to sleep disruption in the intensive care unit (ICU) that may result in increased patient morbidity such as delirium and prolonged length of stay in ICU. We conducted a pre-post intervention study in a 24-bed tertiary care academic medical ICU to reduce the mean noise levels. Baseline dosimeter recordings of ICU noise levels demonstrated a mean noise level of 54.2 A-weighted decibels (dBA) and peak noise levels of 109.9 dBA, well above the Environmental Protection Agency’s recommended levels. There were 1735 episodes of “defects” (maximum noise levels > 60 dBA). Following implementation of multipronged interventions, although the mean noise levels did not change significantly between pre- and post-intervention (54.2 vs 53.8 dBA; p = 0.96), there was a significant reduction in the number of “defects” post-intervention (1735 vs 1289, p ≤ 0.000), and the providers felt that the patients were sleeping longer in the ICU post-intervention.

Transpulmonary hypothermia: A novel method of rapid brain cooling through augmented heat extraction from the lungs ☆

AIM Delay in instituting neuroprotective measures after cardiac arrest increases death and decreases neuronal recovery. Current hypothermia methods are slow, ineffective, unreliable, or highly invasive. We report the feasibility of rapid hypothermia induction in swine through augmented heat extraction from the lungs. METHODS Twenty-four domestic crossbred pigs (weight, 50-55kg) were ventilated with room air. Intraparenchymal brain temperature and core temperatures from pulmonary artery, lower esophagus, bladder, rectum, nasopharynx, and tympanum were recorded. In eight animals, ventilation was switched to cooled helium-oxygen mixture (heliox) and perfluorocarbon (PFC) aerosol and continued for 90min or until target brain temperature of 32°C was reached. Eight animals received body-surface cooling with water-circulating blankets; eight control animals continued to be ventilated with room air. RESULTS Brain and core temperatures declined rapidly with cooled heliox-PFC ventilation. The brain reached target temperature within the study period (mean [SD], 66 [7.6]min) in only the transpulmonary cooling group. Cardiopulmonary functions and poststudy histopathological examination of the lungs were normal. CONCLUSION Transpulmonary cooling is novel, rapid, minimally invasive, and an effective technique to induce therapeutic hypothermia. High thermal conductivity of helium and vaporization of PFC produces rapid cooling of alveolar gases. The thinness and large surface area of alveolar membrane facilitate rapid cooling of the pulmonary circulation. Because of differences in thermogenesis, blood flow, insulation, and exposure to the external environment, the brain cools at a different rate than other organs. Transpulmonary hypothermia was significantly faster than body surface cooling in reaching target brain temperature.