RESUMEN
BACKGROUND: This study aims to evaluate the efficacy of an oxygen scavenging mask device in reducing local oxygen concentrations from nasal cannula ventilation compared to a standard open facial surgical field. METHODS: This is a controlled experiment using a custom-fabricated silicone midfacial oxygen scavenging device, SimMan airway management trainer manikin (Laerdal Medical, Stavanger, Norway), handheld oxygen detector (Forensics Detectors, Los Angeles, United States) and oxygen from a Datex Ohmeda Aisys Carestation anesthesia unit (GE HealthCare, Chicago, United States). Oxygen concentrations were measured at 18 facial landmarks (Fig. 1) with nasal cannula flow of 2, 4, and 6 L/min of 100% FiO2 in both masked and unmasked conditions (Fig. 2). RESULTS: The mean oxygen concentration in the facial surgical field was 20.95% with the scavenger mask and 24.8% without (P < 0.001; two-tailed paired t-test). The unmasked condition was associated with suprathreshold oxygen concentration levels at 13 of 18 facial landmarks (Table 1). The device significantly reduced local oxygen concentration at 16 of 18 facial landmarks (Table 1). The device provided safe oxygen concentration levels at all three flow rates, and measured oxygen concentrations directly correlated with oxygen flow rate in the unmasked condition (Table 2). CONCLUSIONS: An oxygen scavenger mask device reduced local oxygen concentrations from nasal cannula ventilation to below the 23% fire threshold in the entire facial surgical field external to the mask in these experiments. The device may reduce intraoperative fire risk in patients that require supplementary oxygen during surgery.
RESUMEN
Orbital involvement in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) is well-described in children but is uncommon in adults. This series reports 2 adult patients with orbital leukemic involvement and summarizes the existing literature. A 37-year-old male with recently diagnosed AML underwent induction therapy and subsequently developed a tan-pink colored sub-conjunctival lesion in the left eye. Incisional biopsy confirmed AML. A 35-year-old male with history of ALL presented with left-sided orbital mass. Fine needle aspiration biopsy confirmed ALL. Literature review of adult-onset orbital leukemia yielded 29 cases of AML and 3 cases of ALL. Orbital involvement of acute adult-onset leukemia tends to be unilateral, presents in the extraconal space and can occur at any point during systemic leukemic disease. Chemotherapy is the mainstay of treatment, often in combination with radiation and/or hematopoietic stem cell transplant.