Estimated metabolic equivalents of task do not correlate with the maximal oxygen consumption of patients undergoing lung resection surgery.

BACKGROUND AND OBJECTIVE: Metabolic equivalent of task (MET) is a physiological measure that represents the metabolic cost of an activity of daily living. One MET is equivalent to the resting metabolic rate. METs can be estimated by questionnaires or calculated by measuring maximal oxygen uptake (VO2max). The aim of this study is to determine whether METs estimated in the pre-consultation (METse) correlates with METs calculated from VO2max (METsVO2). PATIENTS AND METHODS: Retrospective observational study in patients scheduled for lung resection surgery. The estimation of METs was obtained in the pre-consultation according to the 2014 European and American guidelines for preoperative cardiovascular assessment in non-cardiac surgery. VO2max was calculated in the ergometry laboratory. RESULTS: A total of 104 patients were included in the study, of whom 25 (24%) were female. The mean age was 65.1 years (±9.8). In 26 patients (25%), the METse classification correlated with METsVO2 (κ = -0.107 P = .02). In the remaining patients, METse overestimated functional capacity measured by ergometry (METse > METsVO2). CONCLUSIONS: Subjective assessment overestimates functional capacity and should not replace objective testing in patients scheduled for lung resection surgery.

Lung pulse visualized through pleural effusion as a diagnostic sign of complete obstructive atelectasis of the left lung in a critical patient with respiratory failure. / Pulso pulmonar visualizado a través de derrame pleural como signo diagnóstico de atelectasia obstructiva completa del pulmón izquierdo en paciente crítico con insuficiencia respiratoria.

Complete obstructive atelectasis occurs when mucous or a foreign body obstruct one of the main bronchi. Several lung ultrasound signs have been associated with this entity. We describe the case of a patient admitted to the surgical critical care unit in whom lung ultrasound led to a diagnosis of complete obstructive atelectasis, and the presence of pleural effusion provided direct visualization of lung pulse, a sign that has only previously been described by interpreting ultrasound artifacts.

Monitoring pulse pressure variation during lung resection surgery. / Monitorización de la variación de la presión de pulso durante la cirugía de resección pulmonar.

BACKGROUND AND OBJECTIVE: Although pulse pressure variation (PPV) is an effective dynamic parameter widely used to predict the increase in cardiac output after the administration of fluids in abdominal surgery, its use in thoracic surgery is controversial. A study was designed to describe the behaviour of PPV during lung resection surgery. PATIENTS AND METHODS: A prospective observational study was conducted on adult patients scheduled for lung resection surgery. Patients with bleeding greater than 200cc, or those who required vasopressors during data collection, were excluded. The PPV values were collected during different phases: in bipulmonary ventilation (T1), after the start of single lung ventilation, and the opening of the thorax (T2), at the end of the procedure prior to the restoration of the bipulmonary ventilation (T3), and after the closure of the thorax in bipulmonary ventilation (T4). The correlation coefficient of the PPV values at the different times was calculated. RESULTS: The study included 50 consecutive patients. The mean values and standard deviations of PPV in the different phases were: T1, 11.14% (6.67); T2 6.24% (3.21, T3 5.68% (3.19), and T4 7.84% (4.61). The repeated ANOVA measurements found significant differences between the mean values of PPV in the different phases (P<.001). The correlation between the PPV values during T1 and T2 (PPVT1 and PPVT2) was r=0.868 ([P<.001], r2=0.753), while between T3 and T4 (PPVT3 and PPVT4) the correlation was r=0.616 ([P<.001], r2=0.379) between the PPV values in T3 and T4. CONCLUSIONS: PPV presents a predictable behaviour in the course of lung resection surgery, characterised by a decrease of almost half at the beginning of the unipulmonary ventilation and opening of the thorax. It then remains stable throughout the surgery when there are no changes in the intravascular blood volume.