Allison Collins

Efficacy of sleep position modification to treat positional obstructive sleep apnea

OBJECTIVE/BACKGROUND To assess the feasibility and efficacy of sleep position modification in preventing supine sleep and improving sleep-disordered breathing and relevant clinical outcomes in positional obstructive sleep apnea (OSA) patients. PATIENTS/METHODS Eighty-six consecutive participants with moderate positional OSA on routine diagnostic polysomnography underwent a randomized controlled parallel group design trial of 4-weeks treatment using a sleep position modification device (active) or sleep hygiene advice (control). Outcomes were measured at baseline and following a 4-week treatment period. RESULTS There was a significant reduction in the amount of supine sleep in the active group (mean ± SD change from baseline, active group 99.5 ± 85.2 minutes, control group 68.6 ± 103.2 minutes, p = 0.002), and an improvement in apnea-hypopnea index (AHI) (active group reduced by 9.9 ± 11.6, control group reduced by 5.3 ± 13.9, p = 0.013). Post-hoc analyses indicated that positional therapy was most effective for patients with baseline AHI cut-off above 20 (p = 0.02). Logistic regression showed that a treatment response (AHI < 10) was more likely in the active group (OR = 5.57), and those with higher baseline nadir oxygen desaturation (OR = 1.95) and non-supine AHI (OR = 0.55). There were no significant improvements in quality of life, daytime sleepiness, mood, symptoms, neuropsychological measures or blood pressure in the active group. CONCLUSIONS The position device utilized in this study was effective in reducing supine sleep and AHI, which was significant in those with baseline AHI ≥20. Longer duration studies of physical treatments that modify sleep position are needed to explore further whether additional clinical benefits in are achievable.

Phoxilium vs Hemosol-B0 for continuous renal replacement therapy in acute kidney injury☆

PURPOSE This study aimed to compare the biochemical effects of Phoxilium (containing phosphate at 1.2 mmol/L; Gambro Lundia AB, Lund, Sweden) and Hemosol-B0 (Gambro Lundia AB) as dialysate and/or replacement fluid during continuous renal replacement therapy (CRRT). METHODS We examined serum biochemistry in critically ill patients for 42 hours of Phoxilium administration for the prevention of hypophosphatemia during CRRT and compared them with corresponding results in random historical controls who received Hemosol-B0. RESULTS We studied 15 patients in each arm (Phoxilium vs Hemosol-B0). Respective median ages were 57 (49-68) and 64 (57-67) years. Baseline patient illness severity scores, prescribed CRRT effluent rates, and cumulative phosphate intakes were comparable. After 36 to 42 hours of Phoxilium administration, serum phosphate levels increased from 0.95 (0.81-1.13) to 1.44 (1.23-1.78) mmol/L, in contrast to the decline from 1.71 (1.09-2.00) to 0.83 (0.55-1.59) mmol/L with Hemosol-B0 (P=.0001). Serum ionized calcium levels decreased from 1.27 (1.22-1.37) to 1.12 (1.06-1.21) mmol/L with Phoxilium, compared with an increase from 1.09 (0.90-1.19) to 1.20 (1.16-1.25) mmol/L with Hemosol-B0 (P<.0001). Serum bicarbonate, base excess levels, and effective strong ion difference decreased with Phoxilium and were lower than those with Hemosol-B0 at 36 to 42 hours (P<.05). CONCLUSION Phoxilium effectively prevented hypophosphatemia during CRRT but was associated with relative metabolic acidosis and hypocalcemia compared with Hemosol-B0 use.

Biochemical Effects of Phosphate-Containing Replacement Fluid for Continuous Venovenous Hemofiltration

Aims: To examine biochemical effects of phosphate-containing replacement fluid (Phoxilium®) for continuous venovenous hemofiltration (CVVH). Methods: Retrospective comparison of respective serum biochemistry with sequential use of Accusol™ and Phoxilium, each over 48 h of CVVH. Results: We studied 15 critically ill patients. Accusol was switched to Phoxilium after 5 (4–8) days of CVVH. Respective serum biochemistry after 36–42 h of Accusol versus Phoxilium were: phosphate 1.02 (0.82–1.15) versus 1.44 (1.23–1.78) mmol/l, ionized calcium 1.28 (1.22–1.32) versus 1.12 (1.06–1.21) mmol/l, bicarbonate 24 (23–25) versus 20 (19–22) mmol/l, base excess 0 (–2 to 1) versus –4 (–6 to –3) mmol/l (p < 0.001). Cumulative phosphate intakes during respective periods were 69.6 (56.6–76.6) versus 67.2 (46.6–79.0) mmol (p = 0.45). Plasma strong ion differences were narrower with Phoxilium (p < 0.05), with similar strong ion gaps. No additional intravenous phosphate was given during Phoxilium use. Seven patients had serum phosphate >1.44 mmol/l. Conclusions: Phoxilium versus Accusol use during CVVH effectively prevented hypophosphatemia but contributed to mild hyperphosphatemia, and is associated with relative hypocalcemia and metabolic acidosis.

Temporal dynamics of circadian phase shifting response to consecutive night shifts in healthcare workers: Role of light-dark exposure

Shift work is highly prevalent and is associated with significant adverse health impacts. There is substantial inter‐individual variability in the way the circadian clock responds to changing shift cycles. The mechanisms underlying this variability are not well understood. We tested the hypothesis that light–dark exposure is a significant contributor to this variability; when combined with diurnal preference, the relative timing of light exposure accounted for 71% of individual variability in circadian phase response to night shift work. These results will drive development of personalised approaches to manage circadian disruption among shift workers and other vulnerable populations to potentially reduce the increased risk of disease in these populations.