Factors associated with cardiac rhythm disturbances in the early post-pneumonectomy period: a study on 259 pneumonectomies.

OBJECTIVE: To identify predisposing factors associated with cardiac rhythm disturbances during the early post-pneumonectomy period (first 7 postoperative days). MATERIALS AND METHODS: During the study period (1995-1999), 259 pneumonectomies were performed for malignant (244 cases) or benign disease (15 cases). Postoperative monitoring of patients included continuous arterial pressure - rhythm monitoring and pulse oximetry. Cardiac rhythm disturbances during the intensive care unit stay were detected on the monitor screen and recorded with a 12-lead electrocardiogram. Cardiac rhythm disturbances associated with electrolytes or fluid balance abnormality, mediastinal deviation or surgical postoperative complications were excluded from the study. Age of patients, preexisting cardiac disease, side of pneumonectomy, intrapericardial procedures, stage of the malignant disease, expected postoperative FEV(1)<1200 ml, intraoperative transfusions of packed red cells, elevated right heart pressures, low postoperative serum magnesium levels and long operative times were considered as predisposing factors for the development of post-pneumonectomy cardiac rhythm disturbances. Statistical analysis has been made using logistic regression analysis, Student t-test and chi-square test. RESULTS: Cardiac rhythm disturbances were detected in 49 patients (18.91%). Atrial fibrillation/flutter (31 cases), supraventricular tachycardia (14 cases), and premature ventricular contractions (four cases) were the observed rhythm disturbances. Right pneumonectomy versus left pneumonectomy (P<0.0001) and intrapericardial pneumonectomy versus standard pneumonectomy (P<0.0001) were identified as strong predisposing factors for the establishment of post-pneumonectomy cardiac rhythm disturbances. Patients who established post-pneumonectomy cardiac rhythm disturbances had significantly higher (P=0.024) right ventricular systolic pressure (42.50+/-15.50 mmHg) when compared with patients who had postoperative sinus rhythm (29.07+/-7.71 mmHg) and had also longer operative times than patients who did not develop rhythm disturbances (P=0.015). Mortality rate in patients who developed post-pneumonectomy rhythm disturbances was 20.40%. CONCLUSIONS: Cardiac rhythm disturbances observed early after pneumonectomy are mainly of supraventricular origin, complicating right and intrapericardial pneumonectomies, patients with elevated right heart pressures and long operative times, and are associated with high mortality rates.     

Association of sleep duration and quality with immunological response after vaccination against severe acute respiratory syndrome coronavirus-2 infection

Growing evidence suggests that sleep could affect the immunological response after vaccination. The aim of this prospective study was to investigate possible associations between regular sleep disruption and immunity response after vaccination against coronavirus disease 2019 (COVID-19). In total, 592 healthcare workers, with no previous history of COVID-19, from eight major Greek hospitals were enrolled in this study. All subjects underwent two Pfizer–BioNTech messenger ribonucleic acid (mRNA) COVID-19 vaccine BNT162b2 inoculations with an interval of 21 days between the doses. Furthermore, a questionnaire was completed 2 days after each vaccination and clinical characteristics, demographics, sleep duration, and habits were recorded. Blood samples were collected and anti-spike immunoglobulin G antibodies were measured at 20 ± 1 days after the first dose and 21 ± 2 days after the second dose. A total of 544 subjects (30% males), with median (interquartile range [IQR]) age of 46 (38–54) years and body mass index of 24·84 (22.6–28.51) kg/m² were eligible for the study. The median (IQR) habitual duration of sleep was 6 (6–7) h/night. In all, 283 participants (52%) had a short daytime nap. In 214 (39.3%) participants the Pittsburgh Sleep Quality Index score was >5, with a higher percentage in women (74·3%, p < 0.05). Antibody levels were associated with age (r = −0.178, p < 0.001), poor sleep quality (r = −0.094, p < 0.05), insomnia (r = −0.098, p < 0.05), and nap frequency per week (r = −0.098, p < 0.05), but after adjusting for confounders, only insomnia, gender, and age were independent determinants of antibody levels. It is important to emphasise that insomnia is associated with lower antibody levels against COVID-19 after vaccination.     

Diagnostic mini-video assisted thoracic surgery. Effectiveness and accuracy of new generation 2.0 mm instruments

Objective: Recently 2.0 mm mini-VATS has aroused much interest among surgeons involved with endoscopic surgery. We report our initial experience with the first first 54 patients who underwent this procedure. The aim of this study is to evaluate the effectiveness and accuracy of mini-VATS. Methods: 54 patients were undertaken to mini-VATS for diagnostic purposes. Patients were randomly selected and the indication for operation was set by the classic VATS criteria. 35 (65%) patients were treated under general anesthesia, while 19 (35%) patients were treated under local anesthesia. Results: The average length of hospital stay was 1.8 ± 0.9 days. The days of requirement for narcotic analgesia were 1.9 ± 1.0. Diagnostic accuracy was 100%; morbidity and mortality rates were 0%. Conclusions: The high diagnostic accuracy and low operative danger, combined with less postoperative pain, due to minor surgical trauma and faster patient recovery, has established mini-VATS as a dynamic competitor to the classic VATS procedure. Since high technology is a strong partner in endoscopic surgery, a strong potentiality for evolution exists.     

The role of oxygen-derived free radicals in peritoneal adhesion formation induced by ileal ischaemia/reperfusion

The effectiveness of superoxide dismutase (SOD), catalase (CAT), dimethyl sulphoxide (DMSO) and allopurinol in prevention of peritoneal adhesion formation induced by complete vascular obstruction and reperfusion of an ileal segment was investigated in rats. The ischaemic period was 30 min. Group A (n = 20) were controls, group B (n = 15) received SOD 15,000 U/kg i.v. and group C (n = 17) the same dose of CAT immediately before induction of ischaemia. In group D (n = 20) DMSO 20 mg/kg was given i.v. 5 min before ischaemia, and group E (n = 20) received allopurinol orally 50 mg/kg daily for 2 days and also 2 hours before ischaemia. Ten days later adhesions had developed in 80% of group A, 40% of group B, 47% of group C and 45% of groups D and E (p less than 0.05). The severity of the adhesions was significantly less in the pretreated groups than in the controls. Oxygen-derived free radicals may be pathogenetically important for such adhesion formation. Xanthine oxidase is the principal source of oxygen radicals after a 30-min period of complete regional intestinal ischaemia.     

MRI of pituitary adenomas following treatment

The purpose of this study was to assess pituitary adenomas following surgical and/or medical treatment in 28 patients. All patients were evaluated with both computed tomography (CT) and magnetic resonance imaging (MRI). The results were correlated with the clinical findings. Apart from the visualization of the adenoma itself (either residual or recurrent) other findings and in particular, morphological changes of the optic chiasm, the pituitary stalk and the sellar floor were evaluated with both imaging modalities.By comparing the two imaging modalities it was found that MRI was superior to CT in demonstrating residual/recurrent adenoma as well as evaluating the morphological changes of the optic chiasm and optic nerves. CT was superior or equal to MR in demonstrating the sellar floor changes. The intra-operatively implanted fat was equally seen by CT and MR.In conclusion, the anatomical variations of the optic chiasm and pituitary stalk are better visualized by MRI and allow a more precise evaluation of changes attributed to surgical or medical treatment of pituitary adenomas. Correspondence to: A. Gouliamos     

Pituitary responsiveness to LH-RH during gestation and puerperium in the rhesus monkey

Pituitary gonadotropin response to luteinizing hormone-releasing hormone (LH-RH; 150 micrograms, administered intravenously) was studied during pregnancy and the early postpartum period in rhesus monkeys. Challenge tests were performed approximately every three weeks during pregnancy and every two weeks after delivery, in breast-feeding and non breast-feeding animals. It was found that the response to the releasing factor was completely abolished as early as day 20 after conception. This absence of pituitary responsiveness to LH-RH continued throughout pregnancy. The return of the response during the puerperium occurred as early as day 15 post-delivery in non-breast-feeding monkeys, but remained abolished up of the response to LH-RH in FSH and LH concentration was observed, in that LH levels increased 70%-90%, whereas FSH levels increased only 20%-30%. Serum prolactin (PRL) levels in breast-feeding animals presented a slight increase the first week post-delivery and thereafter, and decreased gradually until they reached normal levels four weeks post-delivery. In contrast, concentrations of serum PRL in non-breast-feeding animals decreased abruptly to normal levels within the first week post-delivery. These results demonstrate that, due to its similarity to the human, the rhesus monkey is an excellent animal model in which to study pituitary function during pregnancy and the puerperium.