AMBULATORY ANESTHESIA AND OBSTETRIC ANESTHESIA Berrin Günaydın, MD, PhD Gazi University Faculty of Medicine Department of Anesthesiology Obstetric Anesthesia Ankara - Turkey SELAMAT PAGI

GAZI UNIVERSITY FACULTY OF MEDICINE

Objectives Definition of ambulatory anesthesia Preoperative Evaluation History taking Physical examination Fasting & medications Laboratory screening Premedication Monitorization Anesthesia choices Postoperative Care for obstetric procedures done on ambulatory basis Ambulatory surgery-anesthesia facilities can be hospital based, freestanding or office based. Primary objective of preop.assessment for the ADULT ambulatory anesthesia is to identfy patients who have concurrent medical problems requiring further diagnostic evaluation or active treatment before surgery. Specific anesthetic concerns (difficult airway orMH susceptibility) or preexisitng medical conditions that may be associated with adverse events include hypertension, obesity, asthma, smoking, and gastroesophageal reflux diseases.

Definition Ambulatory (outpatient) surgery Basic advantages Economic savings Earlier ambulation Lessened risk of nosocomial infections Anesthesia for ambulatory surgery Patients return home within 24 hours of an operative procedure Ambulatory surgery-anesthesia facilities can be hospital based, freestanding or office based. Primary objective of preop.assessment for the ADULT ambulatory anesthesia is to identfy patients who have concurrent medical problems requiring further diagnostic evaluation or active treatment before surgery. Specific anesthetic concerns (difficult airway orMH susceptibility) or preexisitng medical conditions that may be associated with adverse events include hypertension, obesity, asthma, smoking, and gastroesophageal reflux diseases.

Procedures done on ambulatory basis Evacuation of incomplete miscarriage Surgical treatment of tubal ectopic pregnancy Cervical cerclage External cephalic version Hysterosalpingography (HSG) - Hysteroscopy Assisted reproductive technologies - procedures Transvaginal ultrasound guided oocyte retrieval (TUGOR) Selection of surgical procedures commonly undertaken as day-cases Gynae: D&C, laparoscopy, VTOP, colposcopy

Preoperative Evaluation History taking Questionnaires for screening & detecting common medical problems Maternal death & anesthetic history Relevant obstetric history Medical history is clearly the most valuable of the 3 primary components of preop.assessment (1. history, p. Exam, laboratory testing).MH susceptible patients can be successfully managed with non-trigering anesthetics under local anesthesia.After uneventful surgery-anesthesia, MH susceptible patients should be observed for at least 4 hours postoperatively and their families should be advised about the signs of MH in addition to the usual postoperative instructions.

Preoperative Evaluation Physical examination Measurement of vital signs (pulse, blood pressure, respiratory rate, temperature) Airway, heart & lung examination Back examination (when neuraxial anesthesia is planned)

Preoperative Evaluation Fasting & Chronic medications Clear fluids Modest amount is allowed up to 2 h prior to induction of anesthesia Solids should be avoided 6-8 h depending on the type of ingestion (e.g.fat) Patients should bring their own medications Antihypertensives should be taken Oral hypoglycaemics should be omitted Nil by mouth:NPO. Fasting policies have allowed patients to continue taking chronic medications (up to 30 min before surgery) and avoid uncomfortable symptoms of dehydration, hypoglycemia, and cafeine withdrawal. White P. Ambulatory anesthesia advances into the new ilennium. Anesth Analg 2000 Hawkins. ASA Practice Guidelines for Obstetric Anesthesia IJOA 2007

Preoperative Evaluation Laboratory screening Platelet count Maternal history Physical examination Clinical signs Blood type & cross-match Anticipated hemorrhage Institutional policies Age Men ♂ Women ♀ <40 None Pregnancy test 40-49 ECG Htc 50-64 Hb/ Htc, ECG 65-74 Hb/ Htc ECG, BUN Glucose >75 Chest radiograph Laboratory test recommendations for outpatients under general anesthesia are shown in the table. Patients with chronic diseases like hypertension and diabetes require additional laboratory studies (electrolytes or glucose). Unexplianed Hb < 10 g/dl should undergo further evaluation before elective surgery. Routine platelet count and blood cross-match are not necessary in the healthy and uncomplicated parturients. Hemorrhagic complications are anticipated in placenta accreta in a patient with plasenta previa and previous uterine surgery. White & Freire. Ambulatory (outpatient) Anesthesia. Anesthesia 2005 ASA Task Force on Obstetric Anesthesia Practice Guidelines Anesthesiology 2007

Premedication Benzodiazepines if indicated Alpha-2 agonists Small dose of midazolam IV (1-3 mg) Alpha-2 agonists Clonidine (0.1-0.3 PO) Dexmedetomidine (50-70 µg IM or 50 µg IV) Aspiration prophylaxis (for diabetics & morbid obeses) H2-receptor antagonists (ranitidine) Nonparticulate antacids (sodium citrate) Gastrokinetic agents (metoclopramide) White P. Ambulatory Anesthesia. Anesthesia 2005 Hawkins JL. ASA Practice Guidelines for Obstetric Anesthesia. IJOA 2007

Monitorization Heart rate (maternal & fetal) and ECG Blood pressure (noninvasive) Pulse oximetry (SpO2) Capnometry (ETCO2) BIS Use of electroencephalographic bispectral index monitoring can improve maintenance of anesthesia, thereby facilitate the early recovery process. FHR should be monitored by a qualified individual before and after adminstration of neuraxial labor analgesia but continuous monitoring may not be necessary in every clinical setting and may not be possible during initiation of neuraxila anesthesia. White P. Ambulatory anesthesia advances into the new ilennium. Anesth Analg 2000 ASA Task Force on Obstetric Anesthesia Prcatice Guidelines Anesthesiology 2007

Anesthesia Techniques General Anesthesia Regional anesthesia Monitored Anesthesia Care (MAC) Local Anesthesia Borkowski. Cleveland Clin J Med 2006

General Anesthesia Induction agents Propofol (1.5-2.5 mg/kg) is used widely (easy +quick recovery, clear head, lacks PONV) Sevoflurane (8% in 50% N2O-O2) non-irritant to airway, rapid induction, minimal side-effects, but more PONV Thiopentone (3-6 mg/kg) Midazolam (0.2-0.4 mg/kg) Etomidate (0.2-0.3 mg/kg) Ketamine (0.75-1.5 mg/kg) Endtidal vapor concentration>0.75 MAC (+50% N2O) Borkowski. Cleveland Clin J Med 2006 White. Anesth Analg 2000 Russell R. Summer Update on Obstetric Anesthesia, 2006 Levy D. Three day course on obstetric anesthesia, 2007

General Anesthesia Maintenance TIVA (propofol & remifentanil or alfentanil)-TCI (BIS < 60) Endtidal vapor concentration>0.75 MAC (+50% N2O) Borkowski. Cleveland Clin J Med 2006 White. Anesth Analg 2000 Russell R. Summer Update on Obstetric Anesthesia, 2006 Levy D. Three day course on obstetric anesthesia, 2007

General Anesthesia Maintenance Isoflurane Sevoflurane Desflurane ? N2O

General Anesthesia Muscle relaxants (short and intermediate acting drugs) Mivacurium Rocuronium Cisatracurium Airway Face mask LMA Endotracheal intubation Endtidal vapor concentration>0.75 MAC (+50% N2O) Borkowski. Cleveland Clin J Med 2006 White. Anesth Analg 2000 Russell R. Summer Update on Obstetric Anesthesia, 2006 Levy D. Three day course on obstetric anesthesia, 2007

General Anesthesia Reversal agents Benzodiazepin antagonist (flumazenil) Antichoinesterase drugs Sugammadex (rocuronium antagonist) Opioid antagonists (naloxone)

Spinal anesthesia Advantages Disadvantages Simple-quick procedure Short turnover time Patients are alert Less nausea-vomiting Disadvantages Incidence of headache and radiating back pain Slow return of motor power Difficulty in micturition might delay discharge Rare but significant advers events (neurologic injury, infection) Chakravorty et al. Spinal anesthesia in the ambulatory setting. Ind J Anaesth 2003 Mordecai & Brull Curr Opin Anaesthesiol 2005, Korhonen. Curr Opin Anaesthesiol 2006

Spinal anesthesia Prevention against disadvantages 27 G Whitacre spinal needle is associated with lower incidence of PDPH Older (chloroprocaine) & newer (ropivacaine & levobupivacaine) local anesthetics in conjuction with adjuvant intrathecal medications (opioids, vasopressors) help fast resolution of motor function and ability to micturate Mordecai & Brull Curr Opin Anaesthesiol 2005 Korhonen. Curr Opin Anaesthesiol 2006

Neuraxial anesthetics Ideal neuraxial anesthetic Adaequate analgesia and duration Short recovery Minimal side effects 7.5 mg of spinal hyperbaric bupivacaine is with low incidence of TNS Epidural with 2-chloroprocaine is preferable to spinal anesthesia

Conscious (MAC) vs Unconscious Sedation Mood Alert-cooperative No cooperation Protective reflexes Active-intact Obtunded Vital signs Stable Labile Analgesia Regional/local analgesia Central analgesia Recovery room stay Not prolonged Prolonged/admission Complication risk Low High Postop.complication Infrquent Frequent Mentally incompetent patients Not suitable Suitable

Maintenance (µg/kg/min) Drugs used for MAC Drug Loading dose (µg/kg) Maintenance (µg/kg/min) Alfentanil 10-25 0.25-1 Fentanil 1-3 0.01-0.03 Sufentanil 0.1-0.5 0.005-0.01 Remifentanil - 0.025-0.1 Ketamine 500-1000 10-20 Propofol 250-1000 10-50 Midazolam 25-100

Postoperative Care Pain Multimodal approach NSAID and/or nonopioid analgesics (local anesthetics, acetaminophen, proparacetamol) COX2 inhibitors (celecoxib) LA wound infiltration at the time of surgery patient controlled elastomeric pump Neuraxial opioids NSAIDs are effective in relieving the visceral cramping pain. Diclophenac appears particularly efficacious. NSAIDs reduce need for opioid analgesics up to 30% and opioid related effects (nausea, pruritis, respiratory depression, sedation) and may augment analgesic effect of spinal morphine. NSAIDs are generally safe in breastfeeding parturient due to the large molecular size and high protein binding properties of NSAIDs, there is minimal transfer to breastfeeding neonate compared to opioids. However, potential maternal side effects (gastric bleeding, renal dysfunction, delayed wound healing and bleeding due to impaired platelet function) have raised questions about their use andeffects on breatfeeding neonate especially NSAIDs with long half-lives. When neuraxial block has not been used wound infiltration or ilioinguinal block imprves quality of initial postoperative pain relief. White P. Anesth Analg 2000 Carvalho B. Summer Update on Obstetric Anesthesia, 2006

Postoperative Care PONV Prophylactic antiemetics Multimodal treatment regimen Butyrophenones Phenotiazines Gastrokinetic drugs Anticholinergics Antihistamines Serotonin antagonists (4-8 mg IV) NK-1 antagonists Dexametazone (4-8 mg IV) Acupuncture (P6 and others) NK:Neurokinin White P. Anesth Analg 2000 White & Freire. Anesthesia 2005

Discharge Criteria Aldrete Activity Respiration Circulation Conscious level Color of the skin Postanesthesia Discharge Scoring System (PDSS) Vital signs Activity level Nausea &vomiting Pain Surgical bleeding Chakravorty et al. Spinal anesthesia in the ambulatory setting.Ind J Anaesth 2003

Surgical treatment of miscarriage (vacuum aspiration or D&C) Anesthetic options Target-controlled intravenous sedation-analgesia with propofol & remifentanil Paracervical block (PCB) Sedation + PCB (MAC) Short acting iv induction or inhalation agent (sevoflurane) with short acting opioid/N2O mask ventilation or LMA Termination of pregnancy Nanda K et al. Cochrane Data Base Syst Rev 2006 Fassoulaki et al. No change in plasma endorphine and melatonine levels after sevoflurane anesthesia. JCA 2007

Hysterosalpingography (HSG) Any analgesics (oral or topical) vs placebo or no treatment Topical analgesics vs placebo or no treatment Opioid vs non-opioid analgesics Topical analgesics vs oral analgesics Intaruterine local anesthetic vs PCB HSG is a method of testing tubal patency.Various pharmacological strategies are available that may reduce the pain during the procedure. Ahmad G et al. Cochrane Data Base Syst Rev 2007

Hysteroscopy Local MAC General Regional Spinal anesthesia to T7 level was achieved using 3 mL of 2% isobaric lidocaine (60 mg) with 100 µ epinephrine *TNS was associated with single shot spinal anesthesia HSG is a method of testing tubal patency.Various pharmacological strategies are available that may reduce the pain during the procedure. Lotfallah et al. J Reprod Med. 2005 Farid et al. JCA 2001

Tubal ectopic pregnancy Treatment options requiring anesthesia are salpingectomy or salpingostomy either laparoscopically or open surgery General anesthesia Induction with short acting iv agent (usually propofol) Maintenance with TIVA or sevo/desflurane in N2O/opioid Hajenius PJ et al. Cochrane Data Base Syst Rev 2007

Cervical Cerclage Prevents miscarriage or premature delivery due to cervical incompetence in 85-90% of cases and requires anesthesia Regional usually spinal anesthesia epidural General anesthesia Procedure used to temporarily stitch the cervix closed in pregnant women with a history of miscarriage or premature.

Cervical Cerclage Neuraxial anesthesia (spinal or epidural) Use of low-dose epidural 0.125% bupivacaine with epinephrine & fentanyl Spinal anesthesia lidocaine 30 mg or bupivacaine 5.25 mg both with fentanyl 20 µg have been used successfully for cervical cerclage Procedure used to temporarily stitch the cervix closed in pregnant women with a history of miscarriage or premature. Tsen. What’s new and novel in obstetric anesthesia?IJOA 2005 Schumann & Rafique. Low dose epidural anesthesia for cervical cerclage. CJA 2003; 50:424

External Cephalic Version Spinal analgesia with 7.5 mg bupivacaine (n=36) vs with no analgesia (n=34) Success rate Spinal (66.7%) vs no analgesia (32.4%) (p=0.0004) Spinal analgesia significantly increases success rate of external cephalic version among parturients at term which allows possible normal vaginal delivery Procedure used to temporarily stitch the cervix closed in pregnant women with a history of miscarriage or premature. Weiniger et al. External cephalic version for breech presentation with or without spinal analgesia in nulliparous women at term: a randomized controlled trial. Obstet Gynecol. 2007;110:1343-50

TUGOR General Regional blocks Conscious sedation (MAC) Inhalational anesthesia TIVA Regional blocks Spinal Epidural PCB Conscious sedation (MAC) PCB + IV remifentanil Tsen. Int Anaesthesiol Clin 2007 Gunaydin et al.J Opioid Manag 2007

Gunaydin et al.J Opioid Manag 2007

CONCLUSIONS Ambulatory surgery aims the best patient care possible at the reasonable cost, ambulatory anesthesia must meet these requirements Issues that prolong stay in PACU primarily Pain & PONV after general anesthesia or MAC Unresolved blocks & urinary retention after neuraxial blocks should be managed by choosing appropriate pharmacologic agents (mainly short acting agents with less side effects)

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