Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Preanaesthetic Assessment in neurosurgical patient DR. BHARATI KONDWILKAR Neuroanaeshetist Objectives Optimize quality of care Minimize last minute cancellations Evaluate patient’s 1. Medical history and neurological events 2. Physical examination and neurological status 3. Investigations 4. Past medical records Objectives Minimise risk for anaesthesia Plan anaesthetic technique Plan peri-operative care Develop a rapport with patient Inform and educate patient /relative Ensure patient safety Consent for anaesthesia Neurological system History of Seizures, Neurological deficits, Signs and symptoms of raised (ICP) Transient ischemic attacks (TIA) or stroke. The level of consciousness Neurological physical examination Status of the sensory and motor systems evaluation of cranial nerves. Cardiovascular system Preop cardiovascular disturbances • BP fluctuations, arrhythmias,MI • Consequence of central neurogenic effects on myocardium Pre-existing cardiovascular disease • Hypertension,IHD,heart failure • Valvular heart disease,conduction defects,PVD,DVT Respiratory system Respiratory • Aspiration pneumonia complications • Neurogenic pulmonary edema Pre-existing respiratory disease • COPD, asthma • Restrictive lung disease, OSA Other Medical diseases ● Rheumatoid disease ● Indigestion, heartburn and reflux possibility of hiatus hernia ● Diabetes ● Neuromuscular disorders ● Chronic renal failure ● Jaundice Previous anaesthetics and operations Check the records of previous anaesthetics to rule out or clarify problems such as difficulties with intubation, allergy to drugs given or adverse reactions (e.g. malignant hyperpyrexia) Some patients may have been issued with a ‘Medic Alert’-type bracelet or similar device giving details or a contact number Preoperative medications Antiepileptic medications Dexamethasone/ Steroids Antiplatelet agents or anticoagulants Diuretics Anti-DM, HT/IHD Any other Personal History Smoking/Tobacco Alcohol Drugs Pregnancy Food, sleep, bowel/ bladder Allergy- substance/ drug Physical examination Neurological system Assessment of the neurological state:(GCS) Brief exam of the sensory and motor function Cranial nerve involvement: Occulomotor Facial nerve Glossopharyngeal Vagus nerve Physical examination Cardiovascular system : Arrhythmias Heart failure Hypertension Valvular heart disease Peripheral vascular disease Physical examination Respiratory system Respiratory failure Impaired ventilation Collapse, consolidation, pleural effusion Additional or absent breath sounds Physical examination Musculoskeletal system Any restriction of movement and deformity if a patien has connective tissue disorders Cervical spine Temporo-mandibular joints The airway Look for Limitation of mouth opening Receding mandible Position, number, and health of teeth Size of the tongue soft tissue swelling at the front of the neck Deviation of the larynx or trachea Limitations in flexion and extension of the cervical spine Simple bedside tests Mallampatti criteria: The patient, sitting upright, is asked to open their mouth and maximally protrude their tongue. Thyromental distance: With the head fully extended on the neck, the distance between the bony point of the chin and the prominence of the thyroid cartilage is measured .A distance of <7cm suggests difficult intubation. Calder test: The patient is asked to protrude the mandible as far as possible. The lower incisors will lie either anterior to, aligned with, or posterior to the upper incisors. The latter two suggest a reduced view at laryngoscopy. Wilson score: Increasing weight Reduction in head and neck movement Reduced mouth opening Presence of a receding mandible or Buck-teeth all predispose to increased difficulty with intubation Investigations Investigation should only be ordered if the result would affect the patient’s management Baseline investigations in patients with no evidence of concurrent disease (ASA 1) Investigations Investigation should only be ordered if the result would affect the patient’s management Age >16 yrs Additional investigations Urea and electrolytes: patients taking digoxin, diuretics, steroids, and those with diabetes, renal disease, vomiting, diarrhoea Liver function tests: known hepatic disease, history of high alcohol intake (>50 units/week), metastatic disease, or evidence of malnutrition Blood sugar: diabetics, severe peripheral arterial disease, or taking long-term steroids ECG: hypertensive, with symptoms or signs of ischaemic heart disease, cardiac arrhythmia, or diabetic >40 years of age Chest X-ray: symptoms or signs of cardiac or respiratory disease, or suspected or known malignancy, where thoracic surgery is planned, or in those from areas of endemic tuberculosis who have not had a chest X-ray in the last year Pulmonary function tests: dyspnoea on mild exertion, COPD, or asthma. Measure peak expiratory flow rate (PEFR), forced expiratory volume in 1 second (FEV1), and FVC Patients who are dyspnoeic or cyanosed at rest, found to have an FEV1 <60% predicted or are to have thoracic surgeries, should also have arterial blood gas analysed while breathing air Coagulation screen: anticoagulant therapy, history of bleeding diatheses or history of liver disease or jaundice Sickle-cell screen (sickledex): family history of sickle-cell disease or where ethnicity increases the risk of sickle-cell disease, electrophoresis Cervical spine x-ray: rheumatoid arthritis, a history of major trauma or surgery to the neck or when difficult intubation is predicted Neuro-radiological images: CT scan, MRI and angiography Valuable information pertaining to the size of the lesion, location, possible vascularity and the surrounding structures can be obtained Echocardiography Left ventricular ejection fraction Contractility and ventricular wall motion abnormalities Post-MI ventricular function In valvular lesions, the degree of dysfunction (regurgitation and/or stenosis) can be assessed Medical referral Cardiovascular disease ● Untreated or poorly controlled hypertension or heart failure ● Symptomatic ischaemic heart disease, despite treatment (unstable angina) ● Arrhythmias: uncontrolled atrial fibrillation, paroxysmal supraventricular tachycardia and second and third degree heart block ● Symptomatic or newly diagnosed valvular heart disease or congenital heart disease Respiratory disease ● COPD, particularly if dyspnoeic at rest ● Bronchiectasis ● Asthmatics who are unstable, taking oral steroids or have an FEV1<60% of predicted Endocrine disorders ● Insulin-dependent and non-insulin dependent diabetics who have ketonuria, glycated haemogloblin (hba1c) >10% or a random blood sugar >12 mmol/L ● Hypo or hyperthyroidism symptomatic on current treatment ● Cushing’s or addison’s disease ● Hypopituitarism Renal disease ● Chronic renal failure ● Patients undergoing renal replacement therapy Haematological disorders ● Bleeding diatheses, for example- haemophilia, thrombocytopenia ● Therapeutic anticoagulation ● Haemoglobinopathies ● Polycythaemia ● Haemolytic anaemias ● Leukaemias Pre-op concerns in specific surgeries Supratentorial tumors : Documentation of altered level of consciousness, S/S of raised ICP Sensory or motor deficits and seizures is essential Review the CT and MRI imaging Evaluate hydration and volume status Preoperative management of the electrolyte imbalances Signs and symptoms of raised ICT Apnoea, Dilated and unreactive pupil, C/L hemiplegia, Decreased consciousness, Bradycardia Nausea, vomiting, headache, altered mental status, hypertension, Visual disturbances, papilloedema, U/L pupillary dilatation Awake craniotomy for tumor surgery: There are different techniques of awake craniotomy, such as asleepawake-asleep or monitored anesthesia care with conscious sedation The degree of anxiousness, tolerance to pain and the ability to cooperate are factors to be noted during the preoperative assessment With each technique, airway assessment is of extreme importance, predictors of difficult airway and factors that can favour upper airway obstruction such as obesity and OSA should be noted Preparation of the patient includes psychological preparation, reassurance and educating the patient regarding the events of the procedure including various tests during mapping Pituitary tumors: Acromegaly : Large body mass as well as an unpredictable and difficult airway and OSA Detailed evaluation of the cardiac system Cushing’s disease : Hypertension, glucose intolerance, myelopathy, osteoporosis, obesity, and OSA Obesity, moon facieses, buffalo hump and OSA may be associated with a difficult airway Sodium imbalances may indicate posterior pituitary dysfunction in the form of diabetes insipidus or SIADH Preoperative hypopituitarism : should receive steroid and hormone replacement therapy perioperatively Posterior fossa surgery : Preoperative documentation of loss of gag reflex, laryngeal nerve dysfunction, and altered states of consciousness Positioning : Park bench, prone or sitting Lateral and prone position: increased risk for peripheral nerve injury, eye injury and postoperative blindness Sitting position: increased risks of quadriplegia, paraplegia, facial oedema, macroglossia, and venous air embolism (VAE). The incidence of VAE is high (39%) in the sitting position Preoperatively rule out the presence of an intracardiac ( persistent foramen ovale) or an intrapulmonary shunt if proposed position of patient is sitting Cerebral aneurysm: SAH: multisystem involvement Intracranial complications-rebleeding,vasospasm,hydrocephalus,clot, seizure Cardiac complications- abnormalities in rhythm, elevated cardiac enzymes, myocardial dysfunction Respiratory complications - neurogenic pulmonary edema Electrolyte abnormalities - hyponatremia, hypokalemia, hypomagnesaemia and hypocalcaemia Cerebral vasospasm, consider treatment with “Triple H therapy” Most patients are started on calcium blocker, usually nimodipine, and this should be continued preoperatively Cerebral arteriovenous malformation Perioperative blood pressure management Induced hypotension is frequently used intraoperatively to reduce bleeding and postoperatively strict control of the blood pressure is often needed to minimize complications such as bleeding and hyperperfusion syndrome Availability of blood for transfusion is essential, as blood loss can be substantial during the surgical resection Interventinal neuroradiology(coiling and stenting of aneurysms, embolisation of AVM, arteriovenous fistula, and vascular tumors, and stenting of carotid artery stenosis ) Assessment and preparation of these patients also involves ensuring that they are suitable for radiological procedures. Pregnancy Renal function H/o allergy to contrast dyes, protamine sulphate Coagulation status Remote location Manipulation of hemodynamics includes induced hypotension and even the use of adenosine to stop the heart during delivery of the embolic materials Functional neurosurgery: (Deep Brain Stimulators) Preferred technique local anesthesia with monitored care Elderly patients with multiple comorbidities Patients should be assessed for their ability to cooperate and ability to tolerate the various stages of this surgery which include placement of a head frame, preoperative imaging, and the insertion and testing of the DBS Assessment of the airway Medications used to treat motor symptoms are often withheld on the morning of the surgery Premedications such as opiods, benzodiazepines, and other sedatives can interfere with the interpretation of tremor and hence is avoided. The decision to preoperatively withhold anti parkinson drugs may result in a patient with severe symptoms of rigidity or tremors Epilepsy surgery (insertion of cortical electrodes for mapping and activation of the epileptogenic focus, and craniotomy for resection of the focus that may be with awake craniotomy or under general anesthesia) Administration of anticonvulsant agents prior to surgery is done in consultation with the neurologist and surgeon Specific concerns of patients with epilepsy include the accompanying medical problems such as psychiatric disorders, neurofibromatosis, and multiple endocrine adenomatosis. Specific anesthetic considerations include adverse effects of antiepileptic drugs such as confusion, sedation, ataxia and nausea and vomiting, induction of liver enzymes Risks of having anaesthesia? The culprits Human errors Adverse drug reactions Drug interactions Complications: Minor Major Failed iv access Aspiration Cut lip,damage to teeth,caps,crowns Hypoxic brain damage Sore throat MI,CVA PONV Nerve injury,renal failure Retention of urine Death ASA physical status scale Classification of operation National confidential enquiry into perioperative outcome and death (NCEPOD) has identified four categories: 1. Immediate: to save life, limb, organ, resuscitation goes hand in hand 2. Urgent: surgery normally takes place when resuscitation is complete 3. Expedited: stable patient requiring early intervention. Condition not an immediate threat to life, limb, or organ 4. Elective: surgery planned and booked in advance of admission to hospital Obtaining informed consent What is consent? Consent is an agreement by the patient to undergo a specific procedure. The pre-anaesthetic assessment should include confirmation with the patient, the patient’s guardian in the case of children below 18 years or the intellectually challenged, of the nature of the anaesthetic procedure and his / her consent for anaesthesia Documentation A written summary of the pre-anaesthetic assessment, orders or arrangements should be explicitly and legibly documented in the patient’s anaesthetic record. What about an unconscious patient? thank you