The instructions commonly used for preparation of a patient prior to procedure are described here. There may be variations according to hospitals or clinics. Often there are standard protocols for preoperative preparation according to the procedure but they may not be followed rigidly. In keeping with the concept of personalized care, modifications may be made according to condition or special requirements of an individual patient.
For a patient requiring anesthesia, the anesthetist has the following tasks the day prior to surgery:
| • Review the medical records, take the relevant history, and do a physical examination. |
| • Determine general medical fitness of the patient to undergo surgery and note if there are special considerations for anesthesia in a patient with neurological disorder. |
| • Explains preoperative preparation to the patient, particularly nothing per oral requirements. |
Preoperative nothing per oral. Most of the instructions concern food, fluids, and oral medications prior to elective surgery. The main concern is aspiration pneumonia, as general anesthesia depresses protective airway reflexes that normally prevent regurgitated gastric contents from entering the lungs.
Although most of the standard preoperative orders blankly state nothing per oral to be effective at midnight prior to day of surgery, further modifications can be made according to the guidelines of the American Society of Anesthesiologists (01).
Fluids. From 2 to 6 hours prior to surgery, an adult patient can have up to 250 ml of clear fluids that are defined as:
| • Plain water |
| • Fruit juice without pulp, eg, apple juice |
| • Mineral water without gas |
| • Clear tea |
| • Black coffee |
Alcoholic drinks such as beer and wine are excluded from this list. The patient should have no clear liquids within 2 hours prior to surgery.
Food. Nothing per oral instructions for food are:
| • No breastfeeding in case of an infant within 4 hours of surgery |
| • A light meal, eg, toast and clear drink, may be taken up to 6 hours before surgery |
| • No food (includes milk and baby formulas as a liquid foods) within 6 hours of surgery |
| • No fried foods, fatty foods, or meat within 8 hours of surgery as these foods are associated with delayed gastric emptying and even more than 8 hours may be needed for the stomach to empty |
Premedications. Medications are optional and according to the condition and needs of the patient. The following may be given orally prior to surgery.
| • Metoclopramide, a gastrointestinal stimulant, may be used for patients with a slow gastric emptying time. |
| • Omeprazole, a proton pump inhibitor, may be used to block gastric acid secretion in patients with history of gastroesophageal reflux disease or peptic ulcer to reduce chances of aspiration pneumonia. |
| • Ondasetron, an antiemetic, may be given to prevent vomiting in the postoperative period or during the procedure under sedation or local anesthesia. |
| • For anxious patients who are unable to sleep during the night before the operation, a hypnotic may be prescribed. |
The administration of preoperative anticholinergics such as atropine to reduce the risk of pulmonary aspiration is not recommended.
Oral medications. Medications that can be taken on the morning of surgery are:
| • Continue cardiovascular medications such as antiarrhythmics and antihypertensive clonidine (use a transdermal patch) but not ACE inhibitors and calcium channel blockers. |
| • Continue antiepileptic medications. |
| • Continue anti-Parkinson medications except selegiline and rasagiline (MAO inhibitors) as there is risk of interaction with perioperative opioids. Medications are usually stopped in a Parkinson disease patient prior to deep brain stimulation to assess the effect of the procedure but there is a rare risk of potentially fatal Parkinsonism-hyperpyrexia syndrome manifested by pyrexia, muscle rigidity, reduced level of consciousness, and autonomic instability (04). The situation is somewhat complicated as some patients are already resistant to anti-Parkinson drugs or manifest adverse effects. A safe approach would be to reduce the dose of anti-Parkinson medication slowly prior to discontinuation and reintroduce it after deep brain stimulation. |
| • Benzodiazepines may be continued as anesthetic need may be reduced and abrupt discontinuation may lead to withdrawal symptoms. |
| • Antidepressants may be continued as discontinuation may lead to withdrawal symptoms. |
| • Patients with chronic schizophrenia continue neuroleptic/antipsychotic medications as discontinuation may precipitate psychotic symptoms, although these patients become susceptible to the hypotensive action of general anesthesia. Administration of halogenated inhalational anesthetic agents may precipitate malignant hyperthermia, a condition that resembles neuroleptic malignant syndrome, which is a known complication of neuroleptics. |
| • Patients on corticosteroids (equivalent of > 5 mg/day of prednisone) during 6 months prior to surgery should receive stress dose of steroids prior to surgery. Long-term use of steroids suppresses adrenals which do not respond adequately to stress of surgery. |
| • Pain medications such as acetaminophen can be taken but not aspirin or nonsteroidal antiinflammatory agents. Pain medications may be withheld if the patient is undergoing deep brain stimulation for pain or periradicular injection for relief from sciatic pain. |
| • Levothyroxine can be continued. |
Medicines that should not be taken on the morning of surgery include the following:
| • Diuretics or weight loss medications |
| • Potassium supplements |
| • Diabetes medications. Examples are: |
| | - Oral diabetes medications are on hold during the nothing per oral period before surgery |
| | - Basal insulin, eg, Lantus is taken at half dose on night before or morning of surgery |
| | - Bolus insulin, eg, Lispro is on hold during nothing per oral period |
| • No anticoagulants or antiplatelet agents prior to surgery. Duration of withholding and resumption depends on the nature of the surgery to be performed. Withholding is not necessary for noninvasive procedures. |
| • Estrogen and oral contraceptives should be stopped 1 month prior to surgery but not for noninvasive procedures. If their use is continued, precautions should be taken to prevent deep vein thrombosis during surgery and the postoperative period. |
| • Tamoxifen, a selective estrogen receptor modulator, should be stopped for at least 1 week before operations at high risk for thromboembolism, but only in consultation with patient's oncologist. It is not necessary to stop tamoxifen for noninvasive procedures. |
| • All herbal preparations and supplements should be stopped at least 1 week before surgery. |
Adverse effects of fasting prior to surgery. In addition to hunger and thirst, patients may experience the following adverse effects from fasting prior to a medical procedure (06):
| • Alteration in glucose metabolism |
| • Anxiety, irritability, and headaches |
| • Dehydration, low blood volume, and deleterious effects on the cardiovascular system endocrine and metabolic stress responses. |
| • Fasting may have adverse effects on patient well-being and impede recovery. |
| • A third of patients may fail to take important medications due to misunderstanding of the nothing per oral instructions. |
Current status and future of nothing per oral prior to surgery. Preoperative fasting guidelines are generalized to elective procedures and usually do not distinguish between the ambulatory and inpatient setting. Prevalence of pulmonary aspiration is low now and further changes in preoperative fasting guidelines have been widely discussed.
Rates of prolonged clear fluid fasting of over 4 hours prior to surgery are reported in up to 80% of patients with mean fasting duration of up to 16 hours and beyond. Prolonged fasting may result in adverse effects such as intraoperative hemodynamic instability, postoperative delirium, patient discomfort, and extended hospital length of stay (03). Liberal approaches allowing clear fluids up to 1 hour prior to anesthesia or until premedication/call to the operating room have shown no increase in adverse events among children. Various anesthesia societies now encourage clear fluid intake up to 1 hour prior to elective anesthesia in children. The feasibility and safety of a liberal clear fluid fasting regimen among adults having elective surgery under anesthesia needs to be reevaluated in future studies.
Preoperative preparation according to procedures. The measures listed above apply to surgical procedures in general but they may be modified according to the procedure, particularly if they are noninvasive or minimally invasive.
Preparation of the patient for neuromodulation. Neuromodulation involves use of minimally invasive or noninvasive technologies to deliver a stimulus to specific neurologic sites, eg, brain, spinal cord, cranial nerves, peripheral nerves, etc., for management of neurologic disorders. Transcranial magnetic or electrical stimulation can also be used for neuromodulation
Noninvasive stimulation of the brain may have nausea and vomiting as side effects and it is preferable to have nothing per oral prior to the procedure. A neuromodulator can be implanted on an ambulatory patient under local or general anesthesia. General nothing per oral instructions apply.
Preparation of the patient for transcranial magnetic or electrical stimulation. These are noninvasive procedures not requiring anesthesia. However, nausea and vomiting are among the side effects and general nothing per oral instructions apply.
Preparation of the patient for deep brain stimulation. This is a minimally invasive procedure performed under local anesthesia using stereotactic neurosurgical techniques for placement of electrodes. General instructions for medications and nothing per oral should be followed.
Preparation of a patient for implantation of a spinal cord stimulator device. The devices vary in size and are implanted through an incision on a part of the body excluding the area over the spine where the electrodes are inserted through a small skin incision under local anesthesia, but usually needs removal of a small portion of the lamina during which the patient often requires short duration intravenous anesthesia and is awake again when electrodes are tested. The patient should be on nothing per oral as for general anesthesia.
Preparation of a patient for implantation of an intrathecal drug delivery device. It usually consists of a pump and a catheter. It is used for intrathecal drug delivery in patients with chronic nonmalignant or malignant pain and for management of patients with severe spasticity. These patients should have nothing per oral and other precautions as for patients undergoing a surgical procedure under general anesthesia. The procedure, performed under spinal or general anesthesia, is described elsewhere, but some guidelines for selecting and preparing the patients for the procedure are mentioned below (02).
| • Prior to considering an IT, a complete evaluation of the patient must be made. It is mandatory to have a clear diagnosis, an appropriate physical examination, and a complete psychosocial evaluation, which may be optional for cancer pain, before undertaking an implant. Preoperative requirements include: |
| • The patient should have no contraindication to implantation because of chronic hematologic conditions, eg, severe coagulation disorders, aplastic anemia, etc. |
| • The patient should have no active infection on the skin or elsewhere. |
| • Clearance and elimination of CNS-active medications to be administered intrathecally should be considered in special patient populations such as the elderly, including those with kidney or liver disorders. |
| • The patient should have no psychiatric/psychological abnormalities to contraindicate implantation and no history of substance abuse (alcohol, drugs). |
| • Doses of systemic opioids should be reduced and patients weaned from these prior to implantation of the intrathecal pump because the probability of failure of the procedure is higher if patients are maintained on large amounts of systemic opioids. |
| • Cardiopulmonary assessment is important because of the fear of respiratory depression with the intrathecal drug delivery. CNS depressants should be held off prior to the procedure as they can augment opioid-induced respiratory depression. |
Preparation of the patient for interventional neuroradiology. Patients for cerebrovascular interventions may require general anesthesia and it may be safe to follow the general steps about medications and nothing per oral.
Epidural or periradicular injection for relief of sciatica, usually performed on ambulatory patients, is done with CT guidance in the radiology department under local anesthesia because of the need for communication between the patient and the operator. This procedure is also performed by neurologists and neurosurgeons interested in pain management in various private clinics using fluoroscopic guidance for needle placement. There is no publication describing the requirement of nothing per oral for patients prior to interventional spine procedures performed under local anesthesia. However, instructions for nothing per oral as described may be followed as the patient is lying on the stomach and nausea/vomiting is a possible adverse effect of the local anesthetics. There is no need for making a change in patient’s medications except withholding anticoagulants and analgesics so that relief of pain from the procedure can be assessed.
Preparation of the patient for stereotactic neurosurgery. Frameless or robot-guided modifications as well as traditional stereotactic frame are used mainly for deep brain stimulation and noninvasive radiosurgery of the brain. Future applications of stereotactic approach may extend to other lesions of the brain as well. The patients need to be awake and cooperative. Sedation may be used. General instructions for medications and nothing per oral should be followed.
Preparation of the patient for spinal surgery. Opioids are the most prescribed drug class to treat low back pain and opioid use prior to spine surgery ranges from 20% to over 70% in various reports. Physicians caring for these patients should try to combat opioid abuse prior to surgery as a review of the literature shows that there are several negative outcomes of surgery in these patients including continuation of postoperative opioid use, increased duration of hospitalization as well as healthcare costs, and risk of reoperation (09). A retrospective review of lumbar spinal fusion registry data has shown that opioid use before surgery, younger age, and over 4 levels of spinal fusion are associated with higher opioid use after surgery (07). All studies show that opioid use is associated with worse functional outcome after spinal surgery.
Nothing per oral instructions prior to spinal surgery are the same whether patients have general or spinal anesthesia. Adult patients usually receive an enema the day prior to surgery, shower with an antibacterial soap on the morning of surgery, and have insertion of a urinary catheter prior to moving to the operating room. Preoperative assessment of elderly frail patients for elective surgery should also include cognitive screening using the FRAIL scale (includes 5 components: fatigue, resistance, ambulation, illness, and loss of weight) and the Animal Verbal Fluency test (number of animals named). A prospective study has shown that frailty and cognitive impairment in elderly patients are associated with high risk for the development of postoperative delirium (08).
Anterior cervical discectomy and fusion is a commonly performed spine surgery and patients often undergo preoperative laboratory testing. Multivariable analysis has shown that preoperative high creatinine, anemia, hyponatremia, and leukocytosis are associated with increased risk for adverse outcomes after elective anterior cervical discectomy and fusion and can be used in predictive analyses of 30-day outcomes (10).
Special considerations
During preoperative preparation of neurologic patients for surgery, attention should be paid to special groups. Operations are rarely performed on pregnant neurologic patients unless it is an emergency. Operations on infants require attention to nothing per oral in relation to breastfeeding. Elderly patients should have a thorough medical examination to assess any disorders of other systems besides the neurologic disorder. For example, any renal impairment may require adjustment of drug doses.
