selection of topic

i am called by a nursing school for an observation class on fundamentals of nursing... i thought of giving lecture on nursing process but its long and may be boring so i m thinking about other option and also this is my first teaching so i wana choose short and easy so tht i wont be much worried please help me with the topic selection .......

how about nursing care for surgical patient focusing preoperative care......

plzzzzzzzzzz do help me...........