A punção foi rápida; a bolsa de sangue está pronta.

In Portuguese, a is the feminine singular definite article, so here it means the.

• a punção = the puncture / the needle insertion
• a bolsa = the bag

If you wanted a/an in Portuguese, you would usually use uma:

• uma punção = a puncture
• uma bolsa = a bag

So even though a looks like English a, it often means the.

Portuguese nouns have grammatical gender. Both punção and bolsa are feminine singular nouns.

Because of that, the adjectives that describe them also appear in the feminine singular form:

• a punção foi rápida
• a bolsa de sangue está pronta

A useful pattern: nouns ending in -ção are almost always feminine, so punção being feminine is very normal.

Compare:

• o procedimento foi rápido
• a punção foi rápida

The adjective changes to match the noun.

Here, foi is from ser, and it means was.

That is because it is followed by an adjective:

• foi rápida = was quick

The form foi can also be from ir, but then the meaning is went:

• Ela foi ao hospital = She went to the hospital

So in this sentence:

• A punção foi rápida = The puncture/procedure was quick

not went quick.

Because rápida is describing the puncture, not directly modifying the verb.

Portuguese often uses ser/estar + adjective to evaluate an event or thing:

• A cirurgia foi longa
• A consulta foi tranquila
• A punção foi rápida

Using rapidamente is possible in other structures, but it sounds less natural here. For example:

• O procedimento aconteceu rapidamente

In your sentence, foi rápida is the most natural choice.

This is the classic ser vs. estar distinction.

• foi rápida uses ser because it describes the puncture as a completed event: it was quick.
• está pronta uses estar because ready is seen as a temporary or current state: the blood bag is ready now.

So:

• ser = characteristic, identification, or how something is presented as a fact/event
• estar = state or condition

With pronto/pronta, Portuguese normally uses estar:

• Está pronto
• Está pronta

That is the standard way to say is ready.

Because de sangue is being used in a classifying way: it means blood bag or bag of blood in a general sense.

• bolsa de sangue = a bag for blood / a blood bag

Portuguese often leaves out the article after de when the second noun is general or descriptive.

If you said do sangue, that would usually refer to specific blood already known in the conversation:

• a análise do sangue = the analysis of the blood
• a cor do sangue = the color of the blood

So in your sentence, de sangue is the natural form.

In medical Portuguese, punção is a technical word for a puncture or needle insertion. In a context involving blood collection, it often refers to the act of inserting the needle into the vein.

So depending on the situation, it may correspond to English expressions like:

• the puncture
• the needle insertion
• the venipuncture
• sometimes simply the stick

It is a more medical or formal word than everyday speech would usually use.

The semicolon links two closely related complete statements:

• A punção foi rápida
• a bolsa de sangue está pronta

A period would also be perfectly correct:

• A punção foi rápida. A bolsa de sangue está pronta.

A semicolon just makes the connection feel tighter. A comma would be less appropriate in careful writing because both sides are full independent clauses.

A rough Brazilian Portuguese pronunciation is:

• punção ≈ poon-SOWN

A few useful details:

• ç sounds like s
• the stress is on the last syllable: pun-ÇÃO
• ão is nasal, which is one of the trickiest sounds for English speakers

So the ending is not a plain ow sound; it is nasalized.

A rough pronunciation guide is:

• bolsa ≈ BOL-sa
• sangue ≈ SAHN-ghee with a hard g
• está ≈ es-TAH
• pronta ≈ PROHN-ta with a nasal on

A few pronunciation notes:

• In Brazil, de is often pronounced very lightly, often close to dji or ji, depending on accent.
• sangue has a hard g, not a soft English j sound.
• The accent in está shows the stress falls on the last syllable.

So the whole phrase sounds roughly like:

BOL-sa deh SAHN-ghee es-TAH PROHN-ta