is creatinine level, an indicator of chronic renal disease

Respected Doctors,
    Is creatinine level, an indicator of chronic renal disease. My father(around 70 now) has been sick in the first quarter of this year 2008. In March-April 2008 doctor suspected he has UTI and treatment started(creatinine was 1.8). He was good for couple of days. He was again sick after few days and hospitalized for a week. He become so week that it was difficult for him to walk(creatinine was 5+). He recovered but not totally creatinine came down to 2.7. Consulted another doctor and we had a diatician to provide a diat chart and it was strictly followed. The problem keeps happening and he gets better after few days. a month before in October 1st week he again was sick with vomiting, stomach disorder etc and again become week. creatinine jumped from 3.1 to 6+ in a week while he was recovering from this. the last test we had a week back and his creatinine  was 9.1 (is it possible?). Doc said its CRF and dialysis will be required in few days.

He was diagnosed high blood pressure 2.5 years before and was not treated for more than a year. His BP is complete in control(110-120 / 60-70) from the last many months. His urine is mostly clear and no swelling in body. His hemoglobin is between 11.5 to12(normal). He do not have any other disease and never been sick in his life(other than cold and flu).
  
He is now getting treated in a different hospital and doctor requested for a fresh test. He said he may require to do biopsy.

Now the question I have is, Is it possible that the only a BP can damage kidney in less than a year and creatinine can be elevated from 1.8 to 9+? The doctor is not convinced with the treatment my father received in past one year. The question comes in mind as why 2 doctor has different views of one case.

Any and every information/discussion will be greatly appreciated.

Best Regards,
Ravi Singh.