Brief Answer:
Read below.

Detailed Answer:
I read your question carefully and I understand your concern.

It might have been useful if you had said something about the diagnosis of your sister. I see in past questions you ask about brain tumor one month ago but there you speak of a friend, now of sister, so I am not sure if it is the same person. Also when you fill the form you say male which is confusing. You should insert the sex and age of the patient which is what interests us doctors from a medical point of view, not yours if that's what you have done.

Your neurosurgeon also should have put some more effort in the discharge papers, his diagnosis is simply hemicranial decompression which means surgery to lower pressure in the skull, but it says nothing about the cause of that high pressure whether a stroke, a tumor etc. There is also no information on history of illness, prior diagnoses etc.

So generally speaking that fever and white blood cell count speaks if an infection. After a brain lesion and surgery the usual causes of infection are lung infections, urinary infections (due to the immobilization of the patient there is increased risk) and more rarely but very dangerous a meningitis, infection involving brain covering layers due t surgery. The urine analysis does not indicate urinary infection, and meningitis should be associated with worsening of neurological condition, lowered consciousness. So I believe a lung infection to be the primary suspect. Antibiotic treatment is needed, there are no antibiotics in her medication. The swelling of the feet may be due to her heart (the fact she takes Lasix makes me think congestive heart failure may be a known problem). In people with heart issues there may be swelling of the feet and because heart and lungs are closely connected when one is affected it might worsen the other.

So bottom line it seems an acute infection in someone whose condition is already fragile from surgery, brain lesion with reduced mobility and heart issues. That can not be treated at home. She must be in a hospital, on an emergency basis, have other blood tests to check for kidney and liver function, electrolytes, chest xray to start with, cultures to determine the causing bacteria and antibiotic therapy.

I remain at your disposal for further questions.

---

Brief Answer:
Read below.

Detailed Answer:
Thank you for the additional information.

You have to know that it is a policy of this site not to give prescriptions and us doctors are asked not to do that. That is for a good reason, because medicine is already complex and involving difficult choices when you are able to physically examine the patient and perform tests, let alone when you do not have that luxury as in our case. That is why it is advised to consider these exchanges as an opportunity for a second opinion not as a primary diagnostic consult, I believe that is stated in the site if you have read all that is written on your screen.

If I had to treat a patient blindly as you ask, I would go with an antibiotic with a wide range of action such as Ceftriaxone in dosage of at least 2g a day in two divided doses. However I repeat that it is advisable even if she can't be moved, at least to have her seen by a physician to test her neck for rigidity which might indicate meningitis auscultate her lungs for infection signs etc. As I said before she is a patient at increased risk and particular caution should be had.

I hope things work out for the best.

---