The Greek e-journal of Perioperative Medicine

3-26

Authors: Schizodimos Th, Iasonidou Ch, Soulountsi V, Kapravelos N

Acute respiratory distress syndrome (ARDS) is an acute inflammatory lung injury, associated with increased pulmonary vascular permeability, increased lung weight, and loss of aerated lung tissue. There remains limited information about the epidemiology, recognition, management, and outcomes of patients with the ARDS, but in-hospital mortality is still high for those with moderate and severe ARDS (40.3% and 46.1%, respectively). Mechanical ventilation does not cure ARDS but simply buys time by maintaining a gas exchange sufficient for survival. The guiding principle of mechanical ventilation of ARDS is the new setting is less harmful to the lung structure than the previous one, thus avoiding the ventilator induced lung injury (VILI). Among outcome studies testing different tidal volumes, only the study comparing the two extreme values tested (6 mL/kg versus 12 mL/kg) showed a significant benefit of lower tidal volume. ‘The best positive end expiratory pressure (PEEP)’ does not exist. Recruitment maneuvers (RMs) are helpful in increasing aerated lung volume, which decreases strain and tidal recruitment/derecruitment. There is no definitive evidence regarding the clinical effectiveness of RMs to improve clinical outcomes of ARDS patients, although RMs may decrease the mortality of patients with ARDS without increasing the risk for major adverse events. There is no evidence for a difference between pressure control versus volume control ventilation in terms of physiological outcome or mortality. The effect of respiratory rate on the occurrence of VILI or outcome in ARDS has not been independently studied. Increasing inspiratory time has been suggested to improve oxygenation. Prone position (PP) is a standard practice in clinical treatment of ARDS patients to improve systemic oxygenation to any patient with moderate or severe ARDS as it may confer a statistically significant mortality advantage. There is evidence that neuromusculal blockade by cisatracurium besylate has an outcome benefit in ARDS patients since they improve lung mechanics and lung inflammation. Optimal dosing and monitoring strategies will need to be further studied.

38-59

Authors: Papapostolou E, Kyparissa M, Fyntanidou B , Besi C , Oloktsidou E, Alexiou I, Pezikoglou I , Grosomanidis V

Evaluation of monitoring readings, taking into account each patient’s pathology as well as the impact of every medical intervention can guide us to make optimal clinical decisions in the periopeative setting. We present three cases in which clinical decisions concerning the management of acute perioperative pulmonary hypertension were based both on haemodynamic monitoring readings and on each patient’s specific pathology. First case: After anesthesia induction in a patient with severe aortic valve insufficiency, an increase in pulmonary artery pressure was recorded. Infusion of isoprenaline, which has a positive chronotropic effect, decreased diastolic time, diastolic blood flow into the left ventricle and also pulmonary artery pressure. Second case: A patient with severe aortic valve stenosis was found with increased pulmonary artery pressure. Intravenous administration of atenolol (1+1mg) reduced the heart rate and the pulmonary artery pressure. Third case: A 15 year old patient with aortic isthmus rupture underwent open surgical repair with graft interposition. After establishment of one lung ventilation and left thoracotomy, pulmonary artery pressure increased. Pulmonary hypertension was managed successfully by oxygen insufflation to the non-ventilated left lung. In our first patient, heart rate increase reduced diastolic time, which decreased the amount of retrograde blood flow into the left ventricle through the regurgitant aortic valve. In the second patient, the heart rate reduction decreased blood flow velocity through the stenotic aortic valve as well as the pressure gradient between left ventricular chamber and aorta. In both patients, enhanced left ventricular function resulted in a reduction in pulmonary artery pressure. Decrease of the alveolar partial pressure of oxygen (PAO2) is the most important parameter that stimulates hypoxic pulmonary vasoconstriction. Oxygen insufflation increased PAO2, resulting in a decrease in pulmonary artery pressure .Clinical decisions based on haemodynamic monitoring readings resulted in effective management of pulmonary hypertension and in a good patient outcome.

71-77

Authors: Tsetsou A, Karageorgou E, Kontostathis N, Karadimos A

This case report describes the rare occurrence of tetraplegia, caused by conversion disorder, in a patient who received spinal anesthesia for arthroscopic surgery. A 35-year-old female with a history of migraine headaches received spinal anesthesia for arthroscopic left knee surgery. On sensory block examination, she was noted to have a T10 level of blockade. During surgery and45 min after performing spinal anesthesia, patient reported bilateral loss of both sensation and motor function of her upper limbs. Patient was hemodynamic stable with absence of respiratory depression or any alteration of consciousness level. Physical signs and symptoms did not correlate with any known anatomical or neurological patterns. MRI imaging revealed no abnormalities. Psychiatric consultation was performed wherein familial stressor circumstances were identified, leading to diagnosis of conversion disorder.