Spinal Anesthesia for Ambulatory Surgery. SubTitles : . Ambulatory Surgeries: - Overview. - Criteria of Selection . Anesthesia Management: - Pre-operative Assessment. - Intra-operative (Spinal). - Post-operative care. Overview on Ambulatory Surgeries. History:
Spinal Anesthesia for Ambulatory Surgery
- Criteria of Selection.
- Pre-operative Assessment.
- Intra-operative (Spinal).
- Post-operative care.
- Over the past 4 decades, ambulatory surgery has grown from less than 10% to over 70% of all elective surgical procedures.
Essential Components of Ambulatory Surgery Facility:
- Procedures associated with major postoperative complications, i.e. bleeding or major fluid shifts (e.g. extensive plastic surgery, reduction mammoplasty, liposuction).
- Procedures requiring prolonged immobilization and parenteral opioid analgesic therapy.
In a large, prospective outcome study, 24% of ambulatory surgical patients were ASA physical status III, and these patients had the same low incidence of morbidity as ASA I and II patients.
by Warner and coworkers, JAMA, 1993
Extreme of Age
(EB: A study found that elderly patients experienced less postoperative cognitive dysfunction and disorientation after ambulatory (versus inpatient surgery). ( Kitz DS, et al, Anesthesiology 1988)
Extreme of Age
1. Potentially life-threatening chronic illnesses (e.g., brittle diabetes, unstable angina, symptomatic asthma).
2. Morbid obesity complicated by symptomatic cardiorespiratory problems (e.g., angina, asthma).
3. Multiple chronic centrally active drug therapies (e.g., use of monoamine oxidase inhibitors such as pargyline and tranylcypromine) and/or active cocaine abuse.
4. Ex-premature infants less than 60 weeks’ postconceptual age requiring general endotracheal anesthesia.
5. No responsible adult at home to care for the patient on the evening after surgery.
- Pre-operative evaluation.
- Pre-operative preparation.
- Literature Review.
Objective : to identify patients who have concurrent medical problems requiring further diagnostic evaluation or active treatment before elective surgery in order to minimize cancellations or complications.
- Identify the general and specific medical condition of patient, medications, and risk assessment.
- Specific anesthetic concerns: airway assessment, active cardiac or respiratory disease, previous operations and anesthesia charts if available.
- Preoperative assessment 1 to 2 weeks before surgery was found to reduce preoperative anxiety when compared with assessment on the evening before surgery.
2. Laboratory testing:
- Routine preoperative laboratory testing of patients before ambulatory surgery is unjustified and extremely wasteful of valuable health care resources.
- For outpatients undergoing superficial surgical procedures (e.g., biopsy, dilatation and curettage, herniorrhaphy, arthroscopy, vein stripping), no laboratory tests appear to be indicated in males, and only a hemoglobin (or hematocrit) test is indicated for adult females of child-bearing age.
- Obviously patient with chronic disease require additional workup accordingly.
Objective: reducing the risks inherent in ambulatory surgery, improving patient outcome, and making the surgical experience more pleasant for the patient and their family.
- The use of premedication in the outpatient setting has been a subject of considerable debate over the past 30 years.
- The primary indications for preoperative medication include anxiolysis, sedation, analgesia, amnesia, and prophylaxis against postoperative emesis and aspiration pneumonia.
- Superior to barbiturate(residual sedation)
- Prospective studies have not found recovery to be prolonged after the use of appropriate doses of sedative premedication in the outpatient setting (midazolam 1-2mg IV).
- Midazolam has become the drug of choice because its shorter elimination half-life and its anesthetic sparing effects and lack of significant side effects facilitate the recovery process after ambulatory surgery.
- In addition to its well-known anxiolytic properties, midazolam may be effective in reducing postoperative pain and nausea and improving patient satisfaction.
- Midazolam (0.5 mg/kg PO) allowed children to be separated from their parents as early as 15 minutes after oral ingestion, without prolonging recovery even after brief surgical procedures.
- In geriatric patients, premedication with midazolam (0.5-1.0 mg IV) did not adversely affect mental and psychomotor recovery, even after brief ambulatory procedures.
- Premedication with α2-adrenergic agonist drugs produce sedation and anxiolysis while also decreasing the heart rate and blood pressure during anesthesia and opioid requirements after surgery.
- Effective in decreasing emergence delirium after sevoflurane anesthesia.
- Reduce emetic symptoms after breast surgery under GA.
- Facilitate glycemic control in type-2 diabetic patients.
- Reduce postoperative myocardial ischemia in patients with preexisting cardiac disease.
- When compared to oral midazolam, less effective in reducing anxiety but produced greater anesthetic- and analgesic-sparing effects in children.
- More highly selective α2-agonist that has a shorter duration of action than clonidine.
- Could prove valuable adjunct during surgery because of its anesthetic and analgesic sparing effects and ability to decrease postoperative pain.
- Very common postoperative complication and contribute to patients’ dissatisfaction and delayed discharge.
- The cost-effective combination of droperidol, dexamethasone, and ondansetron is increasingly being used for antiemetic prophylaxis of outpatients undergoing a wide variety of surgical procedures.
- Antihistamines (e.g. Dimenhydrinate, hydroxyzine) used effectively to prevent PONV specially in middle ear or strabismus surgery. In combination with droperidol can reduce vomiting up to 24 hours without delaying discharge.
- Peripheral Nerve Block.
- IV regional anesthesia.
August Karl Gustav Bier (24 November 1861, Bad Arolsen – 12 March 1949) was German surgeon and the pioneer of spinal anaesthesia.
What to use:
Literature Review Abstracts
A comparison of spinal anesthesia with small-dose lidocaine and general anesthesia with fentanyl and propofol for ambulatory prostate biopsy procedures in elderly patients. (Namiki A et al, 2006).
Design: prospective, randomized blind study.
Patients: 80 patients, ASA 1-2, aged 60-80 years.
Intervention: group L: (40 patients received 10mg spinal hyperbaric Lidocaine), group F/P: (40 patients received 1 mcg/kg fent. and 1mg/kg propofol induction and 90mcg/kg/hrpropofol maintenance)
Results: both groups provided acceptable operating conditions for surgeons – higher incidence of hypotension in F/P group – shorter time for discharge in group F/P – no major postop side effects and high rate of satisfaction in both groups – Significantly lower total costs in L group.
Prilocaineis an amide local anesthetic with similar pharmacologic properties to lidocaine and equipotent to it within a range of 40-70 mg.
- at 60 minutes post anesthesia HP group had partial motor blocking while HB group remained under complete block. - from block time to filling discharge criteria in PACU: HP average time 92 minutes and HB 103 minutes. - Length of stay in PACU : HP 40 minutes, HB 52 minutes. - Fast-track (bypass phase 1 recovery) accomplished in 11 patients on HP and 6 patients of HB.
- HP group sent home 25 minutes earlier than HB group.
- HP 1% is suitable agent for lower body surgical procedures lasting less than 60 minutes.
- There was no incidence of TNS in both groups.
- HP could be an alternative to lidocaine for ambulatory anesthesia.
A prospective, double-blinded, randomized, clinical trial comparing the efficacy of 40 mg and 60 mg hyperbaric 2% prilocaineversus 60 mg plain 2% prilocainefor intrathecal anesthesia in ambulatory surgery. (CamponovoC et al - AnesthAnalg– 2010)
- 90 patients receive one of the three spinal agents for less than 60 minutes procedure.
- No major adverse reactions or transient neurological symptoms were observed in the study.
- Onset and sensory level of block was comparable in all 3 agents.
- The hyperbaric solution showed faster times to motor block onset and shorter duration of surgical block, suggesting its superiority for the ambulatory setting.
Urinary retention after spinal anaesthesia with hyperbaric prilocaine 2% in an ambulatory setting. (KreutzigerJ - Br J Anaesth- 2010)
Urinary retention after spinal anaesthesia with hyperbaric prilocaine 2% in an ambulatory setting. (Kreutziger J - Br J Anaesth - 2010)
- After spinal anaesthesia with hyperbaric prilocaine 2% (60 mg) for ambulatory lower limb surgery, 23% of patients required postoperative urinary catheterization.
- Postoperative bladder ultrasound and early catheterization are essential to avoid bladder distension and facilitate discharge in patients after intrathecalprilocaine 2% administration in ambulatory surgery.