1.25k likes | 1.53k Vues
Regional Anesthetic Complications. Vincent Conte, MD Associate Clinical Professor Nurse Anesthesia Program FIU College of Nursing and Health Sciences. RA Complications. Presentation divided into two sections: Contraindications Complications (both Spinal & Epidural). Assessment.
E N D
Regional Anesthetic Complications Vincent Conte, MD Associate Clinical Professor Nurse Anesthesia Program FIU College of Nursing and Health Sciences
RA Complications • Presentation divided into two sections: • Contraindications • Complications (both Spinal & Epidural)
Assessment • If a neuraxial anesthetic is being considered, the risks and benefits need to be discussed with the patient • An INFORMED CONSENT needs to be obtained prior to performing any neuraxial anesthetic • A careful H & P and PE need to be done to make sure there are no CONTRAINDICATIONS to performing a neuraxial anesthetic
Assessment • Patients should understand prior to their block, that once the block is performed they will have little or no motor function until the effects of the block wears off • Patients should also be warned that once the block takes effect, they may feel like their limbs are in various positions (straight up, bent or folded, etc.) but are really still and flat against the bed or any rests or padding that you provide
Physical Exam • Prior to ANY Spinal or Epidural anesthetic, a CAREFUL examination of the back should be made. Things to look for are: Surgical Scars Scoliosis Skin lesions Palpable Spinous Processes
Physical Exam • Although no preoperative screening tests are required for healthy patients undergoing neuraxial blockade, coagulation studies and platelet count should be checked when clinical history suggests the possibility of a bleeding diasthesis
Contraindications • There are certain ABSOLUTE contraindications to Regional Anesthesia: • Infection at the site: Could theoretically pre-dispose patients to hematogenous spread of the infectious agents into the epidural or subarachnoid space
Contraindications 2) Patient Refusal: Any denial by the patient should end there and then; DO NOT continue to try to convince a patient for regional anesthesia unless you have a valid medical reason to persist; even then a NO is a NO!!!! Just make sure you document that the “patient was offered a regional and risks/benefits were explained, but patient refused”
Contraindications 3) Coagulopathy or other Bleeding Diasthesis: Do I really need to explain why not in these circumstances???? (Just Kidding) If they can’t clot then you stick the minimum number of needles into a patient (hopefully just an IV and that is it!!)
Contraindications 4) Severe Hypovolemia: Any sympathectomy will compound the hypotension TREMENDOUSLY 5) Increased Intracranial Pressure: Any increase can lead to a brain stem herniation if a spinal is performed and even a minute amount of CSF is lost
Contraindications 6) Severe Aortic Stenosis: Any change in SVR or preload and hypovolemia can result in SEVERE myocardial ischemia and Sudden Cardiac Death; NOT GOOD 7) Severe Mitral Stenosis: Any change in SVR can lead to sudden Right Heart failure and rapid onset of Pulmonary edema
Relative Contraindications • Relative Contraindications are: 1) Systemic Sepsis: For the same reason as an infection at the site, if bacteremia exists, it can be possible to seed the CNS during your procedure (For me, it’s a NO GO) Also, systemic sepsis is usually accompanied by Relative Hypovolemia (peripheral vasodilation) which can become much worse with an added drop in SVR from your block
Relative Contraindications 2) An Uncooperative Patient: Regional anesthesia requires at least some degree of patient cooperation. This may be difficult or impossible for patients with dementia, psychosis, or emotional instability (MOST OF YOU!!!)
Relative Contraindications 3) Preexisting Neurological Deficits: Patients with preexisting neurological deficits may report that their symptoms are worse following a block (Usually through their Lawyer!!) It may be impossible to discern effects or complications of the block from preexisting deficits or unrelated exacerbation of preexisting disease
Relative Contraindications 3) Careful documentation is a MUST in any patient with preexisting neurological deficits and documentation of an explanation of risks/benefits and possible worsening of symptoms is MANDATORY!!!!! (To me, another NO GO) • This is a major source of liability connected with the use neuraxial blockade
Relative Contraindications 4) Stenotic Valvular Heart Lesions: The management of any valvular heart lesion suggests minimal to moderate decreases in SVR (encourage forward flow) and keeping the heart rate normal to slightly decreased (to allow more filling times). The use of Regional Anesthesia can accomplish a reduction in SVR but you will usually have a compensatory rise in heart rate and sometimes the drop in SVR can be very precipitous
Relative Contraindications 4) Stenotic Valvular Lesions (cont’d): In light of these possible complications, IF the use of a Regional Anesthetic is planned, it may be more prudent to use an Epidural and SLOWLY titrate the level of surgical anesthesia via the catheter to minimize the drop in SVR with compensatory increase in heart rate
Relative Contraindications 4) Stenotic Lesions (cont’d): The presence of any valvular heart lesions requires a consultation with Cardiology (if time permits) but most experts recommend AVOIDING a regional anesthetic in the face of SYMPTOMATIC Stenotic lesions, and to USE WITH CAUTION in any stenotic lesions that are ASYMPTOMATIC and use an Epidural rather than a spinal and take your time to titrate the level of anesthetic needed
Relative Contraindications 5) Severe Spinal Deformity: Many anesthetists feel that in the face of severe scoliosis or spinal deformity, the spread of local anesthetic may be altered to such an extent that a high spinal can easily be obtained, or that adequate surgical anesthesia may not be able to be accomplished due to the abnormal spread and distribution secondary to the deformity (My rule is that if it looks real funky and twisted, it is a NO GO)
Controversial Contraindications 1)Prior surgery at the site of injection: After back surgery, the anatomy can be altered tremendously and you may loose the ability to find the epidural space. The spread of your local anesthetic can be altered to a large extent and render your anesthetic useless (My rule is if surgery has been at one level, you can do a spinal at a level below BUT an Epidural will probably fail or end up in a Dural Puncture and is a NO GO; if multiple levels have been worked on, it is a NO GO from the start because the anatomy will be too abnormal, even for a spinal)
Controversial Contraindications 2) Inability to communicate with the patient: With dementia, previous stroke with loss of speech, or with any psychiatric condition that makes communication difficult or impossible, you cannot assess the presence of any signs and symptoms of intravascular injection or high spinal so if you DO use a Regional anesthetic on these patients, you must be VERY CAREFUL about watching your patient for vital sign changes that may indicate adverse reactions
Controversial Contraindications 3) Complicated Surgery: With any complicated surgery, several factors may make a Regional NOT the best choice. a) Possible long (>3 hours) surgery can become very uncomfortable for the patient and require increasing levels of sedation that may compromise respiratory function
Controversial Contraindications 3) b) If the possibility of major blood loss exists, your potential drop in SVR from your regional can be compounded to a severe level. It’s also a pain in the $#@ to have to worry about a semi-awake patient when you are busy transfusing, especially if you need to manage the patient’s airway even just slightly
Controversial Contraindications 3) c) If the surgery involves maneuvers that can compromise respirations (position, high level, pressure on diaphragm) it can be enough to send your patient into respiratory failure if their respiratory function is even slightly compromised by your Regional anesthetic (PLUS, it is very uncomfortable for the patient to feel like they can’t breathe; you’ll need a lot of sedation and that will probably only make the situation worse)
Neuraxial Blockade in the Setting of Anticoagulants & Antiplatelet Agents 1) Oral Anticoagulants (Coumadin): ANY patient on Coumadin, even if given just a few doses in-hospital, needs a PT AND INR prior to surgery (and they need to be normal!!!) Coumadin should be d/c’ed at best a week and at a minimum 5 days prior to surgery and an INR of >1.5 is a CONTRAINDICATION to using a block; <1.5, proceed with caution (use spinal rather than epidural)
Antiplatelet Drugs 2) ASA and other NSAID’s: By themselves do not appear to increase the risk of spinal or epidural hematomas in regional anesthesia. However, if the patient is on chronic therapy or has been taking them for more that 2 weeks, a PFT should be obtained prior to performing a regional anesthetic. Daily baby ASA is safe and can be continued throughout surgery and post-op, but chronic NSAID therapy should be d/c’ed at least 3 days prior to surgery and usually 5-7 days is best
Antiplatelet Drugs 2) Plavix and other related drugs: These drugs are very potent and are an ABSOLUTE contraindication to regional anesthesia. They need to be d/c’ed for AT LEAST 7 days with Plavix, 14 days with Ticlid and 48 hours with Rheopro. All patients on the above medications need a PFT prior to performing any regional anesthetic, even if they have d/c’ed meds for the recommended time periods or longer
Standard Heparin 3) Standard Heparin (unfractionated): Minidose subQ heparin is NOT a contraindication to neuraxial blockade. On patients who are receiving Heparin infusion, the Heparin needs to be d/c’ed for at least 4 hours prior to block and a normal PTT needs to be documented prior to performing your block. If the patient is currently on a Heparin infusion immediately preoperatively, then a regional anesthetic is CONTRAINDICATED
Antiplatelet Drugs 3) Standard Heparin (cont’d): If an epidural cath is placed and then the patient is heparinized, the cath cannot be removed until the heparin is d/c’ed for at least 4 hours and a normal PTT is documented. Also, if bleeding is encountered during the block procedure, at least an hour should pass before the patient is heparinized.
Low-Molecular Weight Heparin 4) Lovenox: If blood or bleeding occurs during your block, Lovenox administration should be delayed for at least 24 hours post procedure. If an epidural cath is in place, it should be removed AT LEAST 2 hours prior to administration of the first dose of Lovenox. If given while a cath IS in place, it cannot be removed for at least 10 hrs. following the last dose, and the next dose cannot be given for at least 2 hours AFTER removal of the cath
Fibrinolytic/Thrombolytic Therapy 5) Fibrinolytic/Thrombolytic Therapy: Is an ABSOLUTE contraindication to regional anesthesia and needs to be d/c’ed for at least 3 days prior to performing a block. COMPLETE clotting studies need to be done and documented NORMAL prior to initiating your block (PT, PTT, INR, PFT, Platelet Count)
SHORT Break Time (stretch)
Complications • The complications of Epidural, Spinal and Caudal anesthetics range from bothersome to the crippling and life-threatening • Broadly, the complications can be thought of as resulting from exaggerated physiologic side effects, placement of the needle, and drug toxicity
Complications • A very large study of regional anesthetics from France provides an indication of the relatively low incidence of serious complications • In contrast, the ASA Closed Claim project helps identify the most common causes of LIABILITY claims involving Anesthetic complications in the OR setting
Complications • In a 20 year period (1980-1999) regional anesthesia accounted for 18% of ALL liability claims. The claims were broken down by: • Temporary or Non-disabling (11.5%) • Serious injuries (death – 2.3%; permanent nerve injury – 1.8%; permanent brain damage – 1.4% and other permanent injuries – 0.72%)
Complications • Lumbar EPIDURAL anesthesia accounted for 42% of all cases • Spinal anesthesia accounted for 34% of all cases • Caudal anesthesia was utilized in only 2% of all cases • ALL types had their complications occur mostly in Obstetric patients (this reflects the higher percentage of use of regional anesthesia in these patients; 68%)
Complications • In the French study, the percentages were MUCH lower • Out of 40,640 patients who had SPINALS, 0.00006% suffered cardiac arrests, 0.0001% died, 0.00004% had permanent nerve injury • Out of 30,413 patients who had EPIDURALS, 0.00009% had cardiac arrests, 0% died and 0.0001% suffered permanent nerve injury (The French have to ALWAYS be better than the Americans in everything!!!)
Exaggerated Physiologic Side Effects • These are: • Hypotension • Bradycardia • High Neural Block • Total Spinal • Cardiac Arrest during Spinal • Urinary Retention • Nausea • Hypoventilation
Hypotension • Hypotension is estimated to occur in about 1/3 of patients receiving spinal anesthesia and in about 1/5 of all patients receiving epidurals • The hypotension results from sympathetic nervous system blockade that: a) Decreases venous return to the heart and that decreases cardiac output b) Decreases Systemic Vascular Resistance (SVR)
Hypotension • Modest decreases in blood pressure are most likely from a drop in SVR • Large drops in blood pressure are from BOTH a drop in SVR & Cardiac Output • The degree of hypotension often parallels the level of spinal anesthesia and the intravascular fluid volume of the patient • With hypovolemia, the extent of hypotension can be markedly increased
Hypotension - Treatment • Is treated physiologically by restoration of venous return so as to increase cardiac output • Head down position (restore volume) • Volume administration (increase preload) • Pharmacologic correction of decreased SVR (Neo) and drop in cardiac output (Ephedrine)
Hypotension-Treatment • BE CAREFUL not to OVER-hydrate patients who may be at risk for heart failure from fluid overload • These are elderly patients, patients with ischemic heart disease or a history of any type of valvular heart disease, patients with a history of Congestive Heart Failure • In these patients, a Neo drip may be needed instead of very aggressive hydration
Bradycardia • Occurs in 10-15% of patients receiving spinal anesthesia • Risk increases with increasing level of anesthesia • Caused by block of cardioaccelerator fibers originating from T1-T4 • Usually promptly responds to treatment with Atropine 0.2-0.4mg • There are reported cases of sudden Asystole in the absence of any obvious preventable events • For Asystole, prompt intervention with Epinephrine is usually necessary to correct the problem
High Neural Blockade • High levels of neural blockade can occur readily with either spinal or epidural anesthesia • Causes are usually: • Administration of an excessive dose • Failure to reduce standard dose in selected patients (elderly, pregnant, obese or very short patients) • Unusual sensitivity or spread of local anesthetic
High Neural Blockade • Spinal anesthesia ascending into the cervical levels causes SEVERE hypotension, bradycardia (blockade of cardiac accelerator fibers) and respiratory insufficiency • Unconsciousness, apnea and hypotension resulting from high levels of spinal anesthesia are referred to as a “High Spinal” or a “Total Spinal”
High Neural Blockade • A High Spinal or Total Spinal can also occur following an attempted epidural/caudal if there is inadvertent intrathecal injection • Sustained severe hypotension with a LOW block can also lead to apnea via severe medullary hypoperfusion
High Neural Blockade • Symptoms of a High neural block include dyspnea and numbness or weakness in the upper extremities • Nausea w or w/o vomiting usually occurs and precedes the development of hypotension • This may continue to develop into severe hypotension, bradycardia and respiratory insufficiency or total apnea
High Neural Blockade • Treatment of a high block or total spinal include supplemental oxygen and maintaining an adequate airway (from a simple chin lift to placement of an ETT) • Treatment also involves support of circulation with volume, head down position and vasopressors (see treatment of hypotension)
High Neural Blockade • If conventional methods do not work with the hypotension, then an Epi drip and boluses may be needed • Bradycardia should be treated promptly with Atropine and/or Epi • If respiratory and hemodynamic control can be maintained, surgery may proceed • If vital signs remain unstable despite aggressive treatment, then surgery should be cancelled and the patient sent to an ICU bed as soon as they are stabilized