Shifts Happen

Night Owl Nursing: Pro’sAutonomyFewer interruptionsStrong camaraderieSalary differentialEasy commute (and parking!)Flexibility with family schedules

Physiology of Night ShiftsMelatonin follows a circadian rhythmHighest melatonin synthesis at nightLight exposure inhibits melatonin

Physiology of Night Shifts

Cross-sectional study of 354 nurses and midwives age 40-60 rotating night to day shift.

> 8 night shifts/per month had lower levels of melatonin metabolites

(Peplonska et al., 2012)

Physiology of Night ShiftsAdjusting to circadian rhythm changes is cellular “Clock genes”Light-at-night (LAN) disrupts the clock genesCellular oxidant-antioxidant balance with the

generation of oxidative stress is upset

Lower levels of Vitamin A and E found in premenopausal women rotating shifts.

(Gromandzinska et al., 2012)

Night Shift RisksType 2 Diabetes

Every 5 year increase of rotating nights shifts- 5% elevated risk of diabetes- adjusted for BMI

Why?Circadian misalignment

- increases glucose and insulin- increases post-prandial glucose response

Diabetes known association with sleep disorders

Night Shift RisksBreast Cancer

“Clock” genes are tumor suppressorsSun exposure may be protectiveLower melatonin results in higher circulating

estrogenOR = 2.6 for long term day-night rotating shifts

(Hansen et al., 2012)

Night Shift Risks

Skin Cancer10+ years of rotating to night shifts

- 14% decreased risk of skin cancer- 44% decrease risk of melanoma

Night Shift RisksPremature Labor

Menstrual Irregularities

Obesity2,086 nursesNight shift rotation associated with obesity

(Zhao et al., 2012)

Night Shift RisksSleep Disturbances

Sleep Quality

Sleep Quantity

Day nurses mean sleep = 8.3 hrsNight nurses mean sleep = 4.8 hrs

Night Owl Nursing: Survival Tips

Night Survival: Light

At work:

34 nurses exposed to bright light during two break times for 4 weeks

Bright lights suppressed nighttime melatonin, increase body temperature, improved alertness

(Zamanian et al., 2010)

Night Survival: Light

After work:Wearing sunglasses before leaving after a

night shift may help circadian rhythm from being triggered

During sleep:Room-darkening, blackout shades, sleep mask

Night Survival: SleepSleep hygiene:

High quality mattress, pillow, covers for comfortCool roomFollow sleep schedule off shiftConsistent bedtime routinesSleep in one episode

Nap before going to workReduces sleep pressure during

subsequent sleep periods

Nap at work!

Night Survival: DietAt work:

High-protein, lo-fatFrequent snacksLots of water!Caffeine Onset of effect 30 min Peak at 4 hoursDuration 6-10 hours Eat main meal around 0100

After work:To sleep: milk, carbsNo caffeine

Night Survival: Activity Regular activityAdequate sun exposureGood communication with friends and familyLimit night schedule to two in a rowAlways rotate forward: days to evenings-evening to nightsBe aware of your breast health

Night Survival

Shift Work Tolerance

322 new and 427 experienced nursesAge related to higher tolerance for shift workHours per week and caffeine related to intolerance

(Saksvik-Lehouillier et al., 2012)

Questions?