Effectiveness of Inferior Oblique Myectomy in Unilateral Superior Oblique Palsy Depending on Magnitude of Hyperdeviation

Purpose@#To evaluate surgical outcome and effectiveness of inferior oblique (IO) myectomy on unilateral superior oblique palsy (SOP) as a primary treatment. @*Methods@#This study is a retrospective review of the medical records of 99 patients who had undergone IO myectomy due to SOP as a first-line treatment. Sixty-five patients with hyperdeviation of 15 prism diopters (PD) or less were categorized into group 1, 22 patients with hyperdeviation between 16 PD to 20 PD into group 2, and 12 patients with hyperdeviation higher than 20 PD into group 3. Preoperative hyperdeviation, postoperative hyperdeviation, and improvement of head tilting were then compared between the 3 groups. Surgery was determined to be successful when the post-op residual hyperdeviation is less than 5 PD, or when the improvement of hyperdeviation and head tilting was noted, for the patients who had preoperative deviation less than 5 PD, and without hypercorrection. @*Results@#All groups showed significant improvement of hyperdeviation, and the amount of correction was larger in group with larger preoperative hyperdeviation. 80.3%, 95.0%, and 90.9% of patients showed improvement of head tiling and success rate was 87.7%, 77.3%, and 50.0% in group 1, 2, and 3 respectively. Group 1 and 2, group 2 and 3 had no significant difference in success rate but only group 1 and 3 had significant difference. @*Conclusions@#Considering success rate with improvement of head position, self-titrating and possibility of overcorrection, IO myectomy could be an effective option as a first-line surgical treatment for unilateral SOP with hyperdeviation of 20 PD or less. However, due to a 50% success rate in patients with hyperdeviation larger than 20 PD, a secondary operation must be considered following IO myectomy, or a two-muscle procedure must be considered as a primary treatment.

Superior Oblique Atrophy on Magnetic Resonance Imaging with Clinical Features in Unilateral Superior Oblique Palsy

Purpose@#To investigate the correlation of superior oblique (SO) atrophy of magnetic resonance imaging (MRI) with clinical features including surgical success in unilateral SO palsy. @*Methods@#This study was a retrospective review of the records of 38 patients who had undergone inferior oblique (IO) myectomy due to SO palsy between January 2017 and March 2019 at our hospital. The patients with more than a 40% decrease of cross-section areas using preoperative orbital MRI were categorized into the atrophic group (16 patients). We compared surgical outcomes between the atrophic and non-atrophic groups. @*Results@#Preoperative IO over-action and vertical deviation showed no significant difference, but the excyclotorsion in paralytic eyes were more frequent in the atrophic group and the surgical success (62.5% vs. 95.5%), and the degree in improvement of vertical deviation (7.17 ± 5.19 prism diopters [PD] vs. 11.05 ± 5.59 PD) was significantly lower in the atrophic group. The degree of SO atrophy showed a weak correlation with the degree of improvement of hypertropia or diopter differences of bilateral head tilting. @*Conclusions@#SO atrophy, detected using preoperative MRI of unilateral SO palsy patients did not show a definite correlation with clinical features except for excyclotorsion in paralytic eyes but did show a clinically significant correlation with surgical outcomes. Preoperative MRI can therefore be used for predicting surgical outcomes of IO myectomy in unilateral SO palsy patients.

Mycophenolic Acid Trough Concentration and Dose Are Associated with Hematologic Abnormalities but Not Rejection in Kidney Transplant Recipients

Background@#Little is known regarding the safe fixed dose of mycophenolic acid (MPA) for preventing biopsy-proven acute rejection (BPAR) in kidney transplant recipients (KTRs). We investigated the correlation of MPA trough concentration (MPA C0) and dose with renal transplant outcomes and adverse events. @*Methods@#This study included 79 consecutive KTRs who received MPA with tacrolimus (TAC) and corticosteroids. The MPA C0 of all the enrolled KTRs was measured, which was determined monthly by using particle-enhanced turbidimetric inhibition immunoassay for 12 months, and clinical data were collected at each time point. The clinical endpoints included BPAR, any cytopenia, and BK or cytomegalovirus infections. @*Results@#No differences in MPA C0 and dose were observed between KTRs with or without BPAR or viral infections under statistically comparable TAC concentrations. MPA C0 was significantly higher in patients with leukopenia (P = 0.021) and anemia (P = 0.002) compared with those without cytopenia. The MPA dose was significantly higher in patients with thrombocytopenia (P = 0.002) compared with those without thrombocytopenia. MPA C0 ≥ 3.5 μg/mL was an independent risk factor for leukopenia (adjusted odds ratio [AOR], 3.80; 95% confidence interval [CI], 1.24–11.64; P = 0.019) and anemia (AOR, 5.90; 95% CI, 1.27–27.51; P = 0.024). An MPA dose greater than the mean value of 1,188.8 mg/day was an independent risk factor for thrombocytopenia (AOR, 3.83; 95% CI, 1.15–12.78; P = 0.029). However, an MPA dose less than the mean value of 1,137.3 mg/day did not increase the risk of BPAR. @*Conclusion@#Either a higher MPA C0 or dose is associated with an increased risk of cytopenia, but neither a lower MPA C0 nor dose is associated with BPAR within the first year of transplantation. Hence, a reduced MPA dose with TAC and corticosteroids might be safe in terms of reducing hematologic abnormalities without causing rejection.

Hemolysis of irradiated leukoreduced red blood cells during rapid warming: An in vitro experimental study

BACKGROUND: Although water chambers are often used as surrogate blood-warming devices to facilitate rapid warming of red blood cells (RBCs), these cells may be damaged if overheated. Moreover, filtered and irradiated RBCs may be damaged during the warming process, resulting in excessive hemolysis and extracellular potassium release. METHODS: Using hand-held syringes, each unit of irradiated and leukocyte-filtered RBCs was rapidly passed through a water chamber set to different temperatures (baseline before blood warming, 50℃, 60℃, and 70℃). The resulting plasma potassium and free hemoglobin levels were then measured. RESULTS: Warming RBCs to 60℃ and 70℃ induced significant increases in free hemoglobin (median [interquartile ranges] = 60.5 mg/dl [34.9-101.4] and 570.2 mg/dl [115.6-2289.7], respectively). Potassium levels after warming to 70℃ (31.4 ± 7.6 mEq/L) were significantly higher compared with baseline (29.7 ± 7.1 mEq/L; P = 0.029). Potassium levels were significantly correlated with storage duration after warming to 50℃ and 60℃ (r = 0.450 and P = 0.001; r = 0.351 and P = 0.015, respectively). CONCLUSIONS: Rapid warming of irradiated leukoreduced RBCs to 50℃ may not further increase the extracellular release of hemoglobin or potassium. However, irradiated leukoreduced RBCs that have been in storage for long periods of time and contain higher levels of potassium should be infused with caution.

Blind nasal intubation as an alternative to difficult intubation approaches

Airway difficulties are a major concern for anesthesiologists. Even though fiberoptic intubation is the generally accepted method for management of difficult airways, it is not without disadvantages-requires patient cooperation, and cannot be performed on soiled airway or upper airways with pre-existing narrowing pathology. Additionally, fiberoptic bronchoscopy is not available at every medical institution. In this case, we encountered difficult airway management in a 71-year-old man with a high Mallampati grade and a thick neck who had undergone urologic surgery. Several attempts, including a bronchoscope-guided intubation, were unsuccessful. Finally, blind nasal intubation was successful while the patient's neck was flexed and the tracheal cartilage was gently pressed down. We suggest that blind nasal intubation is a helpful alternative in difficult airway management and it can be a lifesaving technique in emergencies. Additionally, its simplicity makes it a less expensive option when advanced airway technology (fiberoptic bronchoscopy) is unavailable.

Blind nasal intubation as an alternative to difficult intubation approaches

Airway difficulties are a major concern for anesthesiologists. Even though fiberoptic intubation is the generally accepted method for management of difficult airways, it is not without disadvantages-requires patient cooperation, and cannot be performed on soiled airway or upper airways with pre-existing narrowing pathology. Additionally, fiberoptic bronchoscopy is not available at every medical institution. In this case, we encountered difficult airway management in a 71-year-old man with a high Mallampati grade and a thick neck who had undergone urologic surgery. Several attempts, including a bronchoscope-guided intubation, were unsuccessful. Finally, blind nasal intubation was successful while the patient's neck was flexed and the tracheal cartilage was gently pressed down. We suggest that blind nasal intubation is a helpful alternative in difficult airway management and it can be a lifesaving technique in emergencies. Additionally, its simplicity makes it a less expensive option when advanced airway technology (fiberoptic bronchoscopy) is unavailable.