Comparison on Frequencies of Pericardial Effusion and Tamponade Following Open Heart Surgery in Patients With or Without Low Negative Pressure Suction on Chest Tube

Introduction
Pericardial effusion and tamponade are accounted as the two most important complications following open-heart surgeries which are known to increase mortality and morbidity rates. Putting a low negative pressure suction on the chest tube of patients might be a useful way for better drainage and also reducing the occurrence of pericardial effusion and tamponade. In the present study, we aimed to compare the prevalence of pericardial effusion and tamponade in patients undergoing open-heart surgeries with and without low negative pressure suction on the chest tube.
Methods
This clinical trial was performed in 2018-2019 in Tehran, Iran. 100 patients who were candidates for open-heart surgery were entered. After surgeries, patients were divided into two groups: group 1 had a low negative pressure suction on their chest tube and group 2 had no suction. Patients were then observed for clinical and imaging characteristics of pleural effusion and tamponade. Data were gathered and analyzed using SPSS software.
Results
In the present study, we indicated that the prevalence of pericardial effusion is significantly lower in patients with low negative pressure on their chest tube (P=0.04). No significant differences were observed between two groups regarding to: frequency of tamponade and post-operative ejection fraction (P> 0.05).
Conclusion
The usage of a low negative pressure suction on the chest tube following open cardiac surgeries is associated with a lower prevalence of pericardial effusion. We suggest that such systems could be commonly used in cardiac surgeries or surgeries of the thorax.

Effect of Dexmedetomidine Combined with Inhalation of Isoflurane on Oxygenation Following One-Lung Ventilation in Thoracic Surgery

Background: One-lung ventilation (OLV) is commonly used during thoracic surgery. At this time, hypoxemia is considered one of the remarkable consequences of the anesthesia management. Hypoxic pulmonary vasoconstriction (HPV) is the defense mechanism against hypoxia.
Objectives: The aim of the present study was to investigate the effect of infusion of dexmedetomidine on improving the oxygenation during OLV among the adult patients undergoing thoracic surgery.
Methods: A total of 42 patients undergoing OLV by general anesthesia with isoflurane inhalation were randomly assigned into two groups: IV infusion of dexmedetomidine at 0.3 microgram/kg/h (DISO) and IV infusion of normal saline (NISO). Three Arterial Blood Gas (ABG) samples were obtained throughout the surgery. Hemodynamic parameters, PaO2, PaCO2, and complications at recovery phase were recorded. The collected information was analyzed using SPSS software version 22.
Results: In the dexmedetomidine group, the mean hemodynamic parameters had a significant reduction at 30 and 60 minutes following OLV. Administration of dexmedetomidine resulted in a significant increase in the PaCO2 and a reduction in the PaO2 when changing from two-lung ventilation to OLV, where PaO2 reached its maximum value within 10 minutes after OLV in the DISO group, and it began to gradually increase to the end of operation. The duration of the recovery phase, also complications at the recovery phase decreased significantly in DISO group.
Conclusions: The results of the study showed that, dexmedetomidine may improve arterial oxygenation during OLV in adult patients undergoing thoracic surgery, and can be a suitable anesthetic agent for thoracic surgery.

Global Unmet Needs in Cardiac Surgery.

More than 6 billion people live outside industrialized countries and have insufficient access to cardiac surgery. Given the recently confirmed high prevailing mortality for rheumatic heart disease in many of these countries together with increasing numbers of patients needing interventions for lifestyle diseases due to an accelerating epidemiological transition, a significant need for cardiac surgery could be assumed. Yet, need estimates were largely based on extrapolated screening studies while true service levels remained unknown. A multi-author effort representing 16 high-, middle-, and low-income countries was undertaken to narrow the need assessment for cardiac surgery including rheumatic and lifestyle cardiac diseases as well as congenital heart disease on the basis of existing data deduction. Actual levels of cardiac surgery were determined in each of these countries on the basis of questionnaires, national databases, or annual reports of national societies. Need estimates range from 200 operations per million in low-income countries that are nonendemic for rheumatic heart disease to >1,000 operations per million in high-income countries representing the end of the epidemiological transition. Actually provided levels of cardiac surgery range from 0.5 per million in the assessed low- and lower-middle income countries (average 107 ± 113 per million; representing a population of 1.6 billion) to 500 in the upper-middle-income countries (average 270 ± 163 per million representing a population of 1.9 billion). By combining need estimates with the assessment of de facto provided levels of cardiac surgery, it emerged that a significant degree of underdelivery of often lifesaving open heart surgery does not only prevail in low-income countries but is also disturbingly high in middle-income countries.

Visual impairment and blindness in a population-based study of Mashhad, Iran.

Purpose
To determine the prevalence of visual impairment and blindness and related factors in the 1- to 90-year-old urban population of Mashhad.

Methods
In this cross-sectional study of 1- to 90-year-old residents of Mashhad, in northeastern Iran, sampling was done through random stratified cluster sampling (120 clusters). After selecting the samples and their participation in the study, all subjects had vision testing including measurement of visual acuity and refraction, as well as examinations with the slit-lamp and ophthalmoscopy. Visual impairment (primary outcomes) was defined as a visual acuity worse than of 0.5 logMAR (20/60) in the better eye.

Results
Of the 4453 selected persons, 3132 (70.4%) participated in the study. The prevalence of visual impairment based on presenting vision and best-corrected vision was 3.95% (95% confidence interval [CI]: 3.13–4.77) and 2.23 (95% CI: 1.54–2.91), respectively. The prevalence of presenting visual impairment increased from 1.59% in children under 5 years of age to 43.59% in people older than 65 years of age; these figures were respectively 1.59% and 42.31% based on corrected visual acuity. In the logistic regression model, older age (OR = 1.06, 95% CI: 1.04–1.07, P < 0.001), higher education (OR = 0.16, 95% CI: 0.06–0.38, P < 0.001), and low income (OR = 1.36, 95% CI: 1.21–1.72, P < 0.001) correlated with impaired sight. Based on presenting vision and best-corrected vision, the prevalence of blindness was 0.86% (95% CI: 0.51–1.22) and 0.32% (95% CI: 0.1–0.55). The most common causes of visual impairment were uncorrected refractive error (41.8%) and cataract (20%).

Conclusions
According to our findings, the prevalence of visual impairment was intermediate in comparison with other studies. The prevalence of visual impairment in our study was similar to the global average; however, it was markedly high at older ages. Nonetheless, refractive errors and cataracts remain as the main causes of impaired vision and blindness in this population, while these two conditions are easily treatable with correction or surgery.