Materials and Methods
This prospective and observational study was initiated after obtaining the approval for the study from Izmir Bozyaka Training and Research Hospital Ethics Committee on 27/03/2013 with decision number 17/7. The study evaluated Mini Mental Test (MMT) scores of patients who received total hip replacement surgery in Izmir Bozyaka Training and Research Hospital from November 2013 to September 2014. In the assessment, Mini Mental Test (MMT) was used for literate and Modified Mini Mental Test (MMMT) was used for illiterate patients (7). Test scores were obtained on the initial admission day (MMT1), 24 hours prior to surgery (MMT2) and 24 hours after the surgery (MMT3). A drop of 4 points or more between each test was defined as significant cognitive dysfunction development. Patients who did not have any change or a change less than 4 points between MMT1 and MMT3 were grouped as “no cognitive dysfunction” (Group 1) and patients with a difference more than 4 points between MMT1 and MMT3 were grouped as “cognitive dysfunction” (Group 2). All analyses were performed using those 2 patient groups.
Patients who were planned to undergo total hip replacement surgery without cement over 18 years of age and within ASA Group 1, 2 and 3 according to ASA physical status score were included in the study.
Patients younger than 18, who did not speak Turkish, precense the history of cancer diagnosis, previous steroid treatment, serebro vascular disease history in last 6 months, central nervous system diseases (current meningitis, encephalitis, tumors, major degenerative diseases), dementia, Alzheimer’s and Parkinson’s Disease, neuropsychiatric diseases or received antidepressant, antipsychotic or anticonvulsive treatment in the last 6 months, uncooperative patients, substance abuse, severe organ failure (end-stage liver failure, dialysis-dependent kidney failure), requiring ICU following surgery, patients where regional anesthesia was contraindicated (Idiopathic intracranial hypertension (IIH), clotting disorders, infection on operational site) and pregnant patients were excluded from the study.
No premedication was performed on patients during preoperative period. Hydration during preoperative period was performed by IV 0.9% NaCl aqueous solution with a fasting period of 6-10 hours prior to surgery.
In our study, combined spinal-epidural anesthesia was used for anesthesia for all the patients. Surgical intervention was allowed on the patients with sensory block on T8 dermatome levels. Patients also received gradually 0.5 mg IV bolus midazolam until to be Ramsey Sedation Scale 3.
During anesthesia, decreasing systolic blood pressure more than 20% compared to preoperative period was defined as hypotension. 5 mg IV Ephedrine was administered to the patients when their mean arterial blood pressure levels decreased 50 mmHg or below despite fluid replacement. Bradycardia was defined as pulses below 40 bpm and was treated with 0.5 mg IV atropine.
Postoperative pain management was planned according to Visual Analogue Scale (VAS). In patients with VAS score 3 and above, 10 ml isobaric bupivacaine 0.125% was administered through epidural catheter. No additional medication (opiates or NSAIDs) were used for analgesia.
Demographics, education levels, employment status, operation indications, ASA scores, comorbid diseases and tobacco use of all patients were questioned and recorded. Scores of MMT or MMMT of patients on their initial admission, 24 hours prior to surgery and 24 hours after surgery and its parameters were all recorded and classified.
The period from hospitalization to the surgery date was calculated and recorded. Patients’ hemoglobin, hematocrit, serum electrolyte levels on initial admission, preoperative and postoperative periods, anesthesia duration, surgery duration, administered midazolam, atropine and ephedrine doses, crystalloid, colloid, blood and blood products used during surgery and total blood loss volume were all recorded.