ɐ tˈɛn ˌɛmˈɛl sɪɹˈɪndʒ nˈiːdz təbi jˈuːzd tʊ ɛnʃˈʊɹ kɚɹˈɛkt pɹˈɛʃɚ, wˈɛðɚ juː ɑːɹ ɡˈɪvɪŋ fˈaɪv ˌɛmˈɛl ɔːɹ tˈɛn ˌɛmˈɛl blˈʌd lˈɛft ɪnðə kˈænjʊlə ɔːɹ hˈʌb kæn lˈiːd tə klˈɑːts fˈɔːɹmɪŋ ænd blˈɑːkɪŋ ðə kˈænjʊlə.
A 10ml syringe needs to be used to ensure correct pressure, whether you are giving 5ml or 10ml  Blood left in the cannula or hub can lead to clots forming and blocking the cannula.