Potential rebreathing of carbon dioxide during noninvasive ventilation provided by critical care ventilator.

Background: Critical care ventilators are frequently used to provide noninvasive ventilation (NIV) support to critically ill patients. Questions remain regarding carbon dioxide (CO2) clearance while using a critical care ventilator and dual limb circuit with various patient interfaces. The purpose of this study is to determine the positive end expiratory pressure (PEEP) level required to effectively washout CO2 for full-face and oronasal masks when using a dual limb circuit. Method: This randomized crossover trial was conducted at an academic medical center in the Midwest United States. After obtaining informed consent, eight healthy volunteers were placed on a 980 Puritan Bennett (Medtronic, Minneapolis, MN) ventilator operating in the NIV mode. All subjects performed 20 min of breathing on four levels of PEEP (0, 2, 4, and 5 cm H2O) and pressure support of 5 cm H2O. NIV settings were applied to four masks (two oronasal and two full-face masks) that were randomly selected with a 5-min washout period between each mask. The fraction of inspired carbon dioxide (F ICO2) was sampled/monitored with a nasal cannula using a Capnostream 20p monitor (Medtronic, Minneapolis, MN) and reported as percentages. A Kruskal-Wallis test was used to reveal significant differences across PEEP levels. Pairwise comparisons of the groups were made using Mann-Whitney tests with a family-wise error correction. Results: Median (IQR) F ICO2 was significantly lower 0.0% (0%-0.92%) at PEEP of 5 compared to 1.83% (0.66%-4.0%; p < 0.001) at PEEP of 0 or 1.0% (0.33%-2.66%; p = 0.002) at PEEP of 2. F ICO2 was significantly lower 0.5% (0%-1.92%) at PEEP of 4 compared to PEEP of 0 (p = 0.001). Conclusion: A PEEP level of at least 5 cm H2O associated with the reported leak was required to minimize the likelihood of CO2 rebreathing while using a critical care ventilator to provide NIV with a double limb circuit and full-face or oronasal masks.

The attitude and awareness of contact lens use among medical students of King Faisal University, Al Ahsa, Saudi Arabia.

BACKGROUND: Not many studies have investigated the knowledge outcomes among medical students with regards to contact lenses (CL). Thus, in this study, we aim to assess the attitude and awareness of CL use and the associated factors among medical students of King Faisal University (KFU), Al Ahsa, Saudi Arabia. METHODS: This a cross-sectional study that based developed based on a designed questionnaire that was composed of 31 questions with a maximum score of 57 points. We have also conducted a linear regression model to explore the possible important factors that may affect the level of knowledge and awareness about contact lenses care. RESULTS: A total of 208 participants were included in this study, with a mean age of 21.0 ± 1.9, and 56.3% (n = 117) of them being females. The total mean knowledge score in our study was 30.1 ± 7.74, which was higher in females (31.5 ± 7.09) than in male participants (28.7 ± 7.69). The results of the linear regression model showed that being female (E = -0.37; 95%CI = -0.65- -0.10; P = 0.007), using contact lenses (E = 0.56; 95%CI = 0.29 - 0.82; P < 0.001), and in the third year (E = 0.66; 95%CI = 0.19- 1.13; P = 0.007) is significantly correlated with having higher knowledge scores about using CLs. CONCLUSION: Female participants had higher total mean knowledge scores than males. We recommend that further educational campaigns should be inaugurated to raise awareness about taking care of CLs and enhancing the related practices of wearing them.

Labral Gracilis Tendon Allograft Reconstruction and Cartilage Regeneration Scaffold for an Uncontained Acetabular Cartilage Defect of the Hip.

Hip cartilage injuries are very common, with rates as high as 50% having been reported in some series; abnormal femoral acetabular contact can result in a full-thickness cartilage defect or labral lesion. The prevalence of labral lesions can be as high as 55%. This Technical Note describes an arthroscopic technique to reconstruct an uncontained, full-thickness, focal cartilage defect of the acetabulum, with reconstruction of the missing labrum using a gracilis allograft and use of a biological liquid scaffold for cartilage reconstruction. Capsulotomy, acetabuloplasty, and microfracture with marrow bleeding should be performed simultaneously with the gracilis allograft preparation. The graft is inserted and anchored to reconstruct the missing labrum and to re-create a contained defect. Suction and drying of the joint surfaces are performed while the mixture of BST-CarGel (Piramal Healthcare, Laval, Quebec, Canada) and blood is prepared. A drop-by-drop technique is then used to reconstruct the cartilage defect.