Pain control in first trimester surgical abortion
Regina-Maria Renner, Jeffrey T J Jensen, Mark D N Nichols, Alison Edelman, Regina-Maria Renner, Jeffrey T J Jensen, Mark D N Nichols, Alison Edelman
Abstract
Background: First trimester abortions especially cervical dilation and suction aspiration are associated with pain, despite various methods of pain control.
Objectives: Compare different methods of pain control during first trimester surgical abortion.
Search strategy: We searched multiple electronic databases with the appropriate key words, as well as reference lists of articles, and contacted professionals to seek other trials.
Selection criteria: Randomized controlled trials comparing methods of pain control in first trimester surgical abortion at less than 14 weeks gestational age using electric or manual suction aspiration. Outcomes included intra- and postoperative pain, side effects, recovery measures and satisfaction.
Data collection and analysis: Two reviewers independently extracted data. Meta-analysis results are expressed as weighted mean difference (WMD) or Peto Odds ratio with 95% confidence interval (CI).
Main results: We included forty studies with 5131 participants. Due to heterogeneity we divided studies into 7 groups:Local anesthesia: Data was insufficient to show a clear benefit of a paracervical block (PCB) compared to no PCB or a PCB with bacteriostatic saline. Pain scores during dilation and aspiration were improved with deep injection (WMD -1.64 95% CI -3.21 to -0.08; WMD 1.00 95% CI 1.09 to 0.91), and with adding a 4% intrauterine lidocaine infusion (WMD -2.0 95% CI -3.29 to -0.71, WMD -2.8 95% CI -3.95 to -1.65 with dilation and aspiration respectively).PCB with premedication: Ibuprofen and naproxen resulted in small reduction of intra- and post-operative pain.Analgesia: Diclofenac-sodium did not reduce pain.Conscious sedation: The addition of conscious intravenous sedation using diazepam and fentanyl to PCB decreased procedural pain.General anesthesia (GA): Conscious sedation increased intraoperative but decreased postoperative pain compared to GA (Peto OR 14.77 95% CI 4.91 to 44.38, and Peto OR 7.47 95% CI 2.2 to 25.36 for dilation and aspiration respectively, and WMD 1.00 95% CI 1.77 to 0.23 postoperatively). Inhalation anesthetics are associated with increased blood loss (p<0.001).GA with premedication: The COX 2 inhibitor etoricoxib, the non-selective COX inhibitors lornoxicam, diclofenac and ketorolac IM, and the opioid nalbuphine were improved postoperative pain.Non-pharmacological intervention: Listening to music decreased procedural pain.No major complication was observed.
Authors' conclusions: Conscious sedation, GA and some non-pharmacological interventions decreased procedural and postoperative pain, while being safe and satisfactory to patients. Data on the widely used PCB is inadequate to support its use, and it needs to be further studied to determine any benefit.
Conflict of interest statement
Dr. Renner has no conflicts of interest Dr. Edelman is a consultant for ScheringPharmaceuticals. Dr. Jensen has served on the speakers bureau for Wyeth, Ortho‐McNeil, Pfizer, and Bayer Healthcare Laboratories. He also is a member of the Wyeth & Berlex Contraceptive Advisory Boards. He has received grant support form Wyeth, Pfizer, Ortho‐McNeil, Symbollon, Warner‐Chilcott, and Bayer Healthcare laboratories. Dr. Nichols has served on the speakers bureau for Organon and Bayer Healthcare. He received research funding from Conceptus (manufacturer of Essure).
Drs. Edelman, Jensen, and Nichols have been involved with several of the studies included in this review. These studies did not receive pharmaceutical funding.
Figures
Forest plot of comparison: 2 Local anesthetics, outcome: 2.1 Pain with paracervical block or dilation comparing local anesthetics with bacteriostatic normal saline.
Forest plot of comparison: 2 Local anesthetics, outcome: 2.2 Pain with aspiration comparing local anesthetics with bacteriostatic normal saline.
Forest plot of comparison: 2 Local anesthetics, outcome: 2.3 Pain postpoperatively comparing local anesthetics with bacteriostatic normal saline.
Forest plot of comparison: 2 Local anesthetics, outcome: 2.4 Pain with dilation comparing 2% buffered lidocaine with 2% plain lidocaine.
Forest plot of comparison: 2 Local anesthetics, outcome: 2.6 Pain at end of procedure comparing buffered lidocaine with plain lidocaine.
Forest plot of comparison: 2 Local anesthetics, outcome: 2.5 Pain with aspiration comparing 1% buffered lidocaine with 1% plain lidocaine 20ml each.
Forest plot of comparison: 2 Local anesthetics, outcome: 2.7 Pain with aspiration comparing 0.5% lidocaine with 1% lidocaine 20ml each.
Forest plot of comparison: 2 Local anesthetics, outcome: 2.8 Pain with aspiration comparing 1% lidocaine with 0.25% bupivacaine 20ml each.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.1 Pain with dilation comparing a deep paracervical block with a regular injection technique.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.2 Pain with aspiration comparing a deep paracervical block with a regular injection technique.
Forest plot of comparison: 2 Local anesthesia technique, outcome: 2.3 Pain with PCB placement comparing 4 site (3‐5‐7‐9 o'clock) with 2 site (4‐8 o'clock) PCB.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.3 Pain with aspiration comparing 4 site (3‐5‐7‐9 o'clock) with 2 site (4‐8 o'clock) PCB of 1% chloroprocaine.
Forest plot of comparison: 2 Local anesthesia technique, outcome: 2.5 Pain postoperatively comparing 4 site (3‐5‐7‐9 o'clock) with 2 site (4‐8 o'clock) PCB.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.4 Pain with dilation comparing 3‐5 minute wait with no wait after PCB of 12ml 1% buffered lidocaine.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.5 Pain with aspiration comparing 3‐5 minute wait with no wait after PCB of 12ml 1% buffered lidocaine.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.6 Pain postpoperatively comparing 3‐5 minute wait with no wait after PCB of 12ml 1% buffered lidocaine.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.7 Pain with injection comparing fast injection with slow injection of buffered lidocaine.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.8 Pain with dilation comparing intrauterine lidocaine with placebo.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.9 Pain with aspiration comparing intrauterine lidocaine with placebo.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.10 Pain 30 min postoperatively comparing intrauterine lidocaine with placebo.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.11 Pain with dilation comparing 2% lignocaine gel 10ml with KY jelly 10ml.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.12 Pain with aspiration comparing 2% lignocaine gel 10ml with KY jelly 10ml.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.13 Pain postpoperatively comparing 2% lignocaine gel 10ml with KY jelly 10ml.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.14 Satisfaction with pain control comparing lignocaine gel with KY jelly.
Forest plot of comparison: 3 Paracervical block with premedication, outcome: 3.1 Pain with aspiration comparing ibuprofen 600mg po with placebo in addition to PCB.
Forest plot of comparison: 3 Paracervical block with premedication, outcome: 3.2 Pain postpoperatively comparing ibuprofen 600mg po with placebo in addition to PCB.
Forest plot of comparison: 3 Paracervical block with premedication, outcome: 3.3 Pain with aspiration comparing 1mg lorazepam po with placebo in addition to PCB.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.15 Satisfaction with the abortion experience comparing intrauterine lidocaine with placebo.
Forest plot of comparison: 1 Local anesthesia technique, outcome: 1.16 Satisfaction with the abortion experience comparing deep with regular PCB injection technique.
Forest plot of comparison: 4 Analgesia per os only, outcome: 4.1 Pain with aspiration comparing diclofenac sodium 50mg/misoprostol 200mcg po with misoprostol 200cmg po.
Forest plot of comparison: 4 Analgesia per os only, outcome: 4.2 Pain postoperatively comparing diclofenac sodium 50mg/misoprostol 200mcg po with misoprostol 200mcg po.
Forest plot of comparison: 4 Analgesia per os only, outcome: 4.3 Acceptability of pain control comparing diclofenac sodium/misoprostol po with misoprostol po.
Forest plot of comparison: 5 Conscious sedation, outcome: 5.1 Satisfaction comparing conscious sedation with placebo.
Forest plot of comparison: 5 Conscious sedation, outcome: 5.2 Pain with aspiration comparing PCB and IV sedation with PCB.
Forest plot of comparison: 6 General anesthesia, outcome: 6.1 Postoperative pain comparing halothane and alfentanil.
Forest plot of comparison: 6 General anesthesia, outcome: 6.2 Postoperative pain comparing thiopental and fentanyl with thiopental and halothane.
Forest plot of comparison: 6 General anesthesia, outcome: 6.3 Postoperative pain comparing thiopental and fentanyl with thiopental and enflurane.
Forest plot of comparison: 6 General anesthesia, outcome: 6.4 Postoperative pain comparing trichlorethylen with total IV (methohexital) anesthesia.
Forest plot of comparison: 6 General anesthesia, outcome: 6.5 Blood loss comparing inhalational anesthetics with opiates.
Forest plot of comparison: 6 General anesthesia, outcome: 6.8 Side effects comparing trichloethylene with total IV anesthesia.
Forest plot of comparison: 6 General anesthesia, outcome: 6.6 Anesthetic complications comparing halothane and alfentanil.
Forest plot of comparison: 6 General anesthesia, outcome: 6.7 Side effects comparing enflurane with fentanyl.
Forest plot of comparison: 6 General anesthesia, outcome: 6.9 Recovery time comparing inhalation anesthetics with opiates.
Forest plot of comparison: 6 General anesthesia, outcome: 6.10 Postoperative pain comparing propofol with etomidate.
Forest plot of comparison: 6 General anesthesia, outcome: 6.11 Postoperative pain comparing propofol with thiopental.
Forest plot of comparison: 6 General anesthesia, outcome: 6.12 Postoperative pain comparing propofol with methohexital.
Forest plot of comparison: 6 General anesthesia, outcome: 6.13 Postoperative pain comparing propofol and fentanyl with midazolam and fentanyl.
Forest plot of comparison: 6 General anesthesia, outcome: 6.14 Postoperative pain comparing propofol and alfentanil with ketamine and midazolam.
Forest plot of comparison: 6 General anesthesia, outcome: 6.15 Postoperative pain comparing propofol and ketamine with propofol and fentanyl.
Forest plot of comparison: 6 General anesthesia, outcome: 6.16 Postoperative pain comparing thiopental and fentanyl with ketamine and diazepam.
Forest plot of comparison: 6 General anesthesia, outcome: 6.17 Postoperative pain comparing propofol and alfentanil with propofol.
Forest plot of comparison: 6 General anesthesia, outcome: 6.18 Postoperative pain comparing placebo with alfentanil and fentanyl.
Forest plot of comparison: 6 General anesthesia, outcome: 6.19 Postoperative pain comparing alfentanil with fentanyl when added to propofol.
Forest plot of comparison: 6 General anesthesia, outcome: 6.20 Postoperative pain comparing alfentanil with fentanyl when added to thiopental.
Forest plot of comparison: 6 General anesthesia, outcome: 6.21 Side effects comparing propofol with other sedative hypnotic agents.
Forest plot of comparison: 6 General anesthesia, outcome: 6.24 Side effects comparing propofol and placebo with propofol and either alfentanil or fentanyl.
Forest plot of comparison: 6 General anesthesia, outcome: 6.23 Time to discharge.
Forest plot of comparison: 6 General anesthesia, outcome: 6.24 Pain with dilation comparing conscious sedation and PCB with general anesthesia.
Forest plot of comparison: 6 General anesthesia, outcome: 6.25 Pain with aspiration comparing conscious sedation and PCB with general anesthesia.
Forest plot of comparison: 6 General anesthesia, outcome: 6.26 Postoperative pain comparing conscious sedation and PCB with general anesthesia.
Forest plot of comparison: 6 General anesthesia, outcome: 6.27 Apnea incidence comparing conscious sedation and PCB with genereal anesthesia.
Forest plot of comparison: 6 General anesthesia, outcome: 6.28 Duration of sleep comparing conscious sedation and PCB with general anesthesia.
Forest plot of comparison: 7 General anesthesia with premedication, outcome: 7.1 Postoperative pain comparing paracetamol supp with placebo.
Forest plot of comparison: 7 General anesthesia with premedication, outcome: 7.2 Postoperative pain comparing paracetamol/codeine supp with placebo.
Forest plot of comparison: 7 General anesthesia with premedication, outcome: 7.3 Postoperative pain comparing paracetamol po with placebo.
Forest plot of comparison: 7 General anesthesia with premedication, outcome: 7.4 Postoperative pain comparing paracetamol po with lornoxicam.
Forest plot of comparison: 7 General anesthesia with premedication, outcome: 7.5 Postoperative pain comparing diclofenac with ketorolac and with NaCl.
Forest plot of comparison: 7 General anesthesia with premedication, outcome: 7.6 Postoperative pain comparing etoricoxib with placebo.
Forest plot of comparison: 7 General anesthesia with premedication, outcome: 7.7 Side effects comparing COX inhibitors with placebo as premedication for general anesthesia.
Forest plot of comparison: 7 General anesthesia with premedication, outcome: 7.8 Recovery time comparing COX inhibitors with placebo as premedication for general anesthesia.
Forest plot of comparison: 7 General anesthesia with premedication, outcome: 7.9 Postoperative pain comparing Nalbuphine with fentanyl.
Forest plot of comparison: 7 General anesthesia with premedication, outcome: 7.10 Recovery (reaction time) comparing nalbuphine with fentanyl.
Forest plot of comparison: 7 General anesthesia with premedication, outcome: 7.11 Side effects comparing paracetamol/codeine supp with placebo.
Forest plot of comparison: 7 General anesthesia with premedication, outcome: 7.12 Recovery time (discharge ready) comparing paracetamol/codeine supp with placebo.
Forest plot of comparison: 8 Non pharmacological interventions, outcome: 8.1 Level of comfort during procedure comparing hypnosis with control group.
Forest plot of comparison: 8 Non pharmacological interventions, outcome: 8.2 N2O request comparing hypnosis with a control group.
Forest plot of comparison: 8 Non pharmacological interventions, outcome: 8.3 Pain with aspiration comparing music with methoxyflurane.
Comparison 1 Local anesthetics, Outcome 1 Pain with paracervical block or dilation comparing local anesthetics with bacteriostatic normal saline.
Comparison 1 Local anesthetics, Outcome 2 Pain with aspiration comparing local anesthetics with bacteriostatic normal saline.
Comparison 1 Local anesthetics, Outcome 3 Pain postpoperatively comparing local anesthetics with bacteriostatic normal saline.
Comparison 1 Local anesthetics, Outcome 4 Pain with dilation comparing 2% buffered lidocaine with 2% plain lidocaine.
Comparison 1 Local anesthetics, Outcome 5 Pain with aspiration comparing 1% buffered lidocaine with 1% plain lidocaine 20ml each.
Comparison 1 Local anesthetics, Outcome 6 Pain at end of procedure comparing buffered lidocaine with plain lidocaine.
Comparison 1 Local anesthetics, Outcome 7 Pain with aspiration comparing 0.5% lidocaine with 1% lidocaine 20ml each.
Comparison 1 Local anesthetics, Outcome 8 Pain with aspiration comparing 1% lidocaine with 0.25% bupivacaine 20ml each.
Comparison 2 Local anesthesia technique, Outcome 1 Pain with dilation comparing a deep paracervical block with a regular injection technique.
Comparison 2 Local anesthesia technique, Outcome 2 Pain with aspiration comparing a deep paracervical block with a regular injection technique.
Comparison 2 Local anesthesia technique, Outcome 3 Pain with PCB placement comparing 4 site (3‐5‐7‐9 o'clock) with 2 site (4‐8 o'clock) PCB.
Comparison 2 Local anesthesia technique, Outcome 4 Pain with aspiration comparing 4 site (3‐5‐7‐9 o'clock) with 2 site (4‐8 o'clock) PCB.
Comparison 2 Local anesthesia technique, Outcome 5 Pain postoperatively comparing 4 site (3‐5‐7‐9 o'clock) with 2 site (4‐8 o'clock) PCB.
Comparison 2 Local anesthesia technique, Outcome 6 Pain with dilation comparing 3‐5 minute wait with no wait after PCB of 12ml 1% buffered lidocaine.
Comparison 2 Local anesthesia technique, Outcome 7 Pain with aspiration comparing 3‐5 minute wait with no wait after PCB of 12ml 1% buffered lidocaine.
Comparison 2 Local anesthesia technique, Outcome 8 Pain postpoperatively comparing 3‐5 minute wait with no wait after PCB of 12ml 1% buffered lidocaine.
Comparison 2 Local anesthesia technique, Outcome 9 Pain with injection comparing fast injection with slow injection of buffered lidocaine.
Comparison 2 Local anesthesia technique, Outcome 10 Pain with dilation comparing intrauterine lidocaine with placebo.
Comparison 2 Local anesthesia technique, Outcome 11 Pain with aspiration comparing intrauterine lidocaine with placebo.
Comparison 2 Local anesthesia technique, Outcome 12 Pain 30 min postoperatively comparing intrauterine lidocaine with placebo.
Comparison 2 Local anesthesia technique, Outcome 13 Pain with dilation comparing 2% lignocaine gel 10ml with KY jelly 10ml.
Comparison 2 Local anesthesia technique, Outcome 14 Pain with aspiration comparing 2% lignocaine gel 10ml with KY jelly 10ml.
Comparison 2 Local anesthesia technique, Outcome 15 Pain postpoperatively comparing 2% lignocaine gel 10ml with KY jelly 10ml.
Comparison 2 Local anesthesia technique, Outcome 16 Satisfaction with pain control comparing lignocaine gel with KY jelly.
Comparison 2 Local anesthesia technique, Outcome 17 Satisfaction with the abortion experience comparing intrauterine lidocaine with placebo.
Comparison 2 Local anesthesia technique, Outcome 18 Satisfaction with the abortion experience comparing deep with regular PCB injection technique.
Comparison 3 Paracervical block with premedication, Outcome 1 Pain with aspiration comparing ibuprofen 600mg po with placebo in addition to PCB.
Comparison 3 Paracervical block with premedication, Outcome 2 Pain postpoperatively comparing ibuprofen 600mg po with placebo in addition to PCB.
Comparison 3 Paracervical block with premedication, Outcome 3 Pain with aspiration comparing 1mg lorazepam po with placebo in addition to PCB.
Comparison 4 Analgesia per os only, Outcome 1 Pain with aspiration comparing diclofenac sodium 50mg/misoprostol 200mcg po with misoprostol 200cmg po.
Comparison 4 Analgesia per os only, Outcome 2 Pain postoperatively comparing diclofenac sodium 50mg/misoprostol 200mcg po with misoprostol 200mcg po.
Comparison 4 Analgesia per os only, Outcome 3 Acceptability of pain control comparing diclofenac sodium/misoprostol po with misoprostol po.
Comparison 5 Conscious sedation, Outcome 1 Satisfaction comparing conscious sedation with placebo.
Comparison 5 Conscious sedation, Outcome 2 Pain with aspiration comparing PCB and IV sedation with PCB.
Comparison 6 General anesthesia, Outcome 1 Postoperative pain comparing halothane and alfentanil.
Comparison 6 General anesthesia, Outcome 2 Postoperative pain comparing thiopental and fentanyl with thiopental and halothane.
Comparison 6 General anesthesia, Outcome 3 Postoperative pain comparing thiopental and fentanyl with thiopental and enflurane.
Comparison 6 General anesthesia, Outcome 4 Postoperative pain comparing trichlorethylen with total IV (methohexital) anesthesia.
Comparison 6 General anesthesia, Outcome 5 Blood loss (ml) comparing inhalational anesthetics with opiates.
Comparison 6 General anesthesia, Outcome 6 Anesthetic complications comparing halothane and alfentanil.
Comparison 6 General anesthesia, Outcome 7 Side effects comparing enflurane with fentanyl.
Comparison 6 General anesthesia, Outcome 8 Side effects comparing trichloethylene with total IV anesthesia.
Comparison 6 General anesthesia, Outcome 9 Recovery time (min.) comparing inhalation anesthetics with opiates.
Comparison 6 General anesthesia, Outcome 10 Postoperative pain comparing propofol with etomidate.
Comparison 6 General anesthesia, Outcome 11 Postoperative pain comparing propofol with thiopental.
Comparison 6 General anesthesia, Outcome 12 Postoperative pain comparing propofol with methohexital.
Comparison 6 General anesthesia, Outcome 13 Postoperative pain comparing propofol and fentanyl with midazolam and fentanyl.
Comparison 6 General anesthesia, Outcome 14 Postoperative pain comparing propofol and alfentanil with ketamine and midazolam.
Comparison 6 General anesthesia, Outcome 15 Postoperative pain comparing propofol and ketamine with propofol and fentanyl.
Comparison 6 General anesthesia, Outcome 16 Postoperative pain comparing thiopental and fentanyl with ketamine and diazepam.
Comparison 6 General anesthesia, Outcome 17 Postoperative pain comparing propofol and alfentanil with propofol.
Comparison 6 General anesthesia, Outcome 18 Postoperative pain comparing placebo with alfentanil and fentanyl.
Comparison 6 General anesthesia, Outcome 19 Postoperative pain comparing alfentanil with fentanyl when added to propofol.
Comparison 6 General anesthesia, Outcome 20 Postoperative pain comparing alfentanil with fentanyl when added to thiopental.
Comparison 6 General anesthesia, Outcome 21 Side effects comparing propofol with other sedative hypnotic agents.
Comparison 6 General anesthesia, Outcome 22 Side effects comparing propofol and placebo with propofol and either alfentanil or fentanyl.
Comparison 6 General anesthesia, Outcome 23 Time to discharge.
Comparison 6 General anesthesia, Outcome 24 Pain with dilation comparing conscious sedation and PCB with general anesthesia.
Comparison 6 General anesthesia, Outcome 25 Pain with aspiration comparing conscious sedation and PCB with general anesthesia.
Comparison 6 General anesthesia, Outcome 26 Postoperative pain comparing conscious sedation and PCB with general anesthesia.
Comparison 6 General anesthesia, Outcome 27 Apnea incidence comparing conscious sedation and PCB with genereal anesthesia.
Comparison 6 General anesthesia, Outcome 28 Duration of sleep (min.) comparing conscious sedation and PCB with general anesthesia.
Comparison 7 General anesthesia with premedication, Outcome 1 Postoperative pain comparing paracetamol supp with placebo.
Comparison 7 General anesthesia with premedication, Outcome 2 Postoperative pain comparing paracetamol/codeine supp with placebo.
Comparison 7 General anesthesia with premedication, Outcome 3 Postoperative pain comparing paracetamol po with placebo.
Comparison 7 General anesthesia with premedication, Outcome 4 Postoperative pain comparing paracetamol po with lornoxicam.
Comparison 7 General anesthesia with premedication, Outcome 5 Postoperative pain comparing diclofenac with ketorolac and with NaCl.
Comparison 7 General anesthesia with premedication, Outcome 6 Postoperative pain comparing etoricoxib with placebo.
Comparison 7 General anesthesia with premedication, Outcome 7 Side effects comparing COX inhibitors with placebo as premedication for general anesthesia.
Comparison 7 General anesthesia with premedication, Outcome 8 Recovery time (min.) comparing COX inhibitors with placebo as premedication for general anesthesia.
Comparison 7 General anesthesia with premedication, Outcome 9 Postoperative pain comparing Nalbuphine with fentanyl.
Comparison 7 General anesthesia with premedication, Outcome 10 Recovery (reaction time (msec.)) comparing nalbuphine with fentanyl.
Comparison 7 General anesthesia with premedication, Outcome 11 Side effects comparing paracetamol/codeine supp with placebo.
Comparison 7 General anesthesia with premedication, Outcome 12 Recovery time (discharge ready) comparing paracetamol/codeine supp with placebo.
Comparison 8 Non pharmacological interventions, Outcome 1 Level of comfort during procedure comparing hypnosis with control group.
Comparison 8 Non pharmacological interventions, Outcome 2 N2O request comparing hypnosis with a control group.
Comparison 8 Non pharmacological interventions, Outcome 3 Pain with aspiration comparing music with methoxyflurane.
Source: PubMed