There are multiple definitions:

1. positive pressure ventilation(English)

   • PPB
   • Respiratory system

2. positive predictive value(English)

   • PPV = TP / (TP+FP)
   • NPV, FN, FP, TN, TP
   • Statistics, Screening
   • https://doi.org…pubh.2017.00307

3. pulse pressure variation(English)

   • PP, Eadyn, SVV
   • Hemodynamics, Variability / oscillation, Anesthesiology/analgesia, Surgery
   • https://doi.org…3054-014-0626-6
   • https://doi.org…1093/bja/aeq031

4. Parkinson Patiënten Vereniging(Dutch)

   • LVE
   • Parkinson, Patient-centered (interest group)
   • https://www.zor…ling-apeldoorn/
   • https://www.par…-vereniging.nl/

5. porcine parvovirus(English)

   • ubiquitous among swine worldwide. In general, infection is enzootic in most herds, and with rare exception, while sows are immune. Also, gilts (commonly infected via the oronasal route) usually contract PPV before conception and develop an active immunity that persists through life. The major reservoir for this thermostable virus is environmental
   • Virology, Veterinary medicine
   • https://doi.org…63951-7/50018-1

6. pars plana vitrectomy(English)

   • applied as treatment of primary rhegmatogenous retinal detachment (PRRD)
   • PRRD, RD, SB, OCT, ILM, MHRD, IOAB
   • Ophthalmology, Surgery
   • https://doi.org…2147/opth.s1511
   • https://doi.org…000000000025465

7. prone position ventilation(English)

   • causes improvement in oxygenation, nevertheless, mortality in severe acute respiratory distress syndrome remains high
   • ARDS
   • Critical Care, Respiratory system
   • https://doi.org…als-10071-24643