Difference between revisions of "Dilation and curettage"

From WikiAnesthesia
(Updated intraoperative approach and variant table. Added several citations from the literature.)
 
(13 intermediate revisions by 5 users not shown)
Line 1: Line 1:
Dilation and curettage (D&C), a commonly performed procedure in obstetrics and gynecology, refers to dilation of the cervix in order to introduce instruments into the uterus, with a curette being used to empty or sample the endometrial cavity.
{{Infobox surgical case reference
| anesthesia_type = General, MAC, neuraxial, or regional
| airway = Noninvasive O2 (for sedation, regional, or neuraxial)
LMA/ETT if GA
| lines_access = PIV
| monitors = Standard
| considerations_preoperative = Anxiety
| considerations_intraoperative = Vasovagal response during cervical dilation
| considerations_postoperative = Hemorrhage
Infection
Cervical lacerations
Uterine perforation
}}'''Dilation and curettage''', also known as '''D&C''', is a commonly performed procedure in obstetrics and gynecology which refers to dilation of the cervix in order to introduce instruments into the uterus, with a curette being used to empty or sample the endometrial cavity.


The indication for a D&C may be diagnostic or therapeutic. Diagnostic D&C has largely been replaced by an office endometrial biopsy. However, certain scenarios, including (but not limited to) the inability to tolerate office biopsy due to pain or anxiety, insufficient sampling, the need to exclude endometrial cancer, and cervical stenosis, may necessitate an operative diagnostic D&C over office endometrial biopsy<ref name=":0">{{Citation|last=Cooper|first=Danielle B.|title=Dilation and Curettage|date=2021|url=http://www.ncbi.nlm.nih.gov/books/NBK568791/|work=StatPearls|place=Treasure Island (FL)|publisher=StatPearls Publishing|pmid=33760550|access-date=2021-05-08|last2=Menefee|first2=Gary W.}}</ref>.
The indication for a D&C may be diagnostic or therapeutic. Diagnostic D&C has largely been replaced by an office endometrial biopsy. However, certain scenarios, including (but not limited to) the inability to tolerate office biopsy due to pain or anxiety, insufficient sampling, the need to exclude endometrial cancer, and cervical stenosis, may necessitate an operative diagnostic D&C over office endometrial biopsy<ref name=":0">{{Citation|last=Cooper|first=Danielle B.|title=Dilation and Curettage|date=2021|url=https://www.ncbi.nlm.nih.gov/books/NBK568791/|work=StatPearls|place=Treasure Island (FL)|publisher=StatPearls Publishing|pmid=33760550|access-date=2021-05-08|last2=Menefee|first2=Gary W.|volume=|pages=}}</ref>.


Indications for therapeutic D&C in the pregnant patient are: elective termination of pregnancy (< 14 weeks gestational age), treatment of early pregnancy failure (missed or incomplete spontaneous abortion), evacuation of suspected molar pregnancy, treatment for cervical stenosis, and removal of suspected retained products of conception in the post-partum period.<ref name=":0" />
Indications for therapeutic D&C in the pregnant patient are: elective termination of pregnancy (< 14 weeks gestational age), treatment of early pregnancy failure (missed or incomplete spontaneous abortion), evacuation of suspected molar pregnancy, treatment for cervical stenosis, and removal of suspected retained products of conception in the post-partum period.<ref name=":0" />


 
Therapeutic D&C may be indicated as a temporizing measure in the non-pregnant patient with abnormal uterine bleeding<ref>{{Cite journal|date=April 2013|title=Committee Opinion No. 557: Management of Acute Abnormal Uterine Bleeding in Nonpregnant Reproductive-Aged Women|url=https://journals.lww.com/00006250-201304000-00042|journal=Obstetrics & Gynecology|language=en|volume=121|issue=4|pages=891–896|doi=10.1097/01.AOG.0000428646.67925.9a|issn=0029-7844|last=|first=|via=}}</ref>.
 
Therapeutic D&C may be indicated as a temporizing measure in the non-pregnant patient with abnormal uterine bleeding<ref>{{Cite journal|date=2013-04-XX|title=Committee Opinion No. 557: Management of Acute Abnormal Uterine Bleeding in Nonpregnant Reproductive-Aged Women|url=https://journals.lww.com/00006250-201304000-00042|journal=Obstetrics & Gynecology|language=en|volume=121|issue=4|pages=891–896|doi=10.1097/01.AOG.0000428646.67925.9a|issn=0029-7844}}</ref>.{{Infobox surgical case reference
| anesthesia_type = General, sedation, regional or neuroaxial
| airway = Spontaneous (for sedation, regional, or neuroaxial)
LMA for general
| lines_access = PIV
| monitors = Standard Monitors
| considerations_preoperative = Anxiety provoking procedure
| considerations_intraoperative = Vasovagal response during cervical dilation
| considerations_postoperative = Hemorrhage; infection (1-2%); cervical lacerations; uterine perforation
}}


== Preoperative management ==
== Preoperative management ==
Line 25: Line 26:
!System
!System
!Considerations
!Considerations
|-
|Airway
|
|-
|-
|Neurologic
|Neurologic
Line 30: Line 34:
|-
|-
|Cardiovascular
|Cardiovascular
|
|Hemodynamic instability due to uterine bleeding or possibly septic from retained products of conception
|-
|-
|Respiratory
|Pulmonary
|
|
|-
|-
|Gastrointestinal
|Gastrointestinal
|
|If the patient was pregnant, you may need aspiration precautions depending on how many weeks pregnant
|-
|-
|Hematologic
|Hematologic
Line 48: Line 52:
|-
|-
|Other
|Other
|
|Emotional distress
|}
|}


=== Labs and studies<!-- Describe any important labs or studies. Include reasoning to justify the study and/or interpretation of results in the context of this procedure. If none, this section may be removed. --> ===
=== Labs and studies<!-- Describe any important labs or studies. Include reasoning to justify the study and/or interpretation of results in the context of this procedure. If none, this section may be removed. --> ===
* CBC
* coagulation studies
* blood type and antibody screen, possible crossmatching<ref name=":1" />


=== Operating room setup<!-- Describe any unique aspects of operating room preparation. Avoid excessively granular information. Use drug classes instead of specific drugs when appropriate. If none, this section may be removed. --> ===
=== Operating room setup<!-- Describe any unique aspects of operating room preparation. Avoid excessively granular information. Use drug classes instead of specific drugs when appropriate. If none, this section may be removed. --> ===
* If high-risk for uterine bleeding, consider having Oxytocin (Pitocin), Methylergonovine (Methergine), and/or Carboprost tromethamine (Hemabate) available.


=== Patient preparation and premedication<!-- Describe any unique considerations for patient preparation and premedication. If none, this section may be removed. --> ===
=== Patient preparation and premedication<!-- Describe any unique considerations for patient preparation and premedication. If none, this section may be removed. --> ===
* Special considerations for evacuation of '''molar pregnancy''': hyperemesis gravidarum, preeclampsia, anemia, hyperthyroid, trophoblastic embolization, cardiorespiratory distress; may require additional pre-operative optimization or post-operative monitoring<ref name=":1" />
* <u>Anxiolysis</u>: D&C for miscarriage or termination of pregnancy can be highly anxiety provoking and may instigate severe emotional distress prior to the the procedure. 
* Consider pre-operative acetaminophen.


=== Regional and neuraxial techniques<!-- Describe any potential regional and/or neuraxial techniques which may be used for this case. If none, this section may be removed. --> ===
=== Regional and neuraxial techniques<!-- Describe any potential regional and/or neuraxial techniques which may be used for this case. If none, this section may be removed. --> ===


* Paracervical or intracervical block: Lidocaine 1% placed by obstetrician in 5mL aliquots
* <u>Paracervical</u> or <u>intracervical block</u>: Lidocaine 1% can be injected by the obstetrician in 5mL aliquots to facilitate passage through the cervix and instrumentation of the uterus.  Note that this does not block sensation for the manipulation and instrumentation of the vaginal canal.  Patients who could not tolerate an intra-office procedure may also require sedation in addition to block placement.
* Spinal anesthesia: Shorter acting agents including mepivicaine, chloroprocaine, or low-dose hyperbaric bupivicaine 0.75%. TNS symptoms may follow patients in the ambulatory settings after lithotomy position.<ref>{{Citation|last=Dalby|first=Patricia|title=Anesthesia for Medical Termination of Pregnancy|date=2018|url=http://link.springer.com/10.1007/978-3-319-74766-8_54|work=Anesthesiology|pages=527–534|editor-last=Goudra|editor-first=Basavana G.|place=Cham|publisher=Springer International Publishing|language=en|doi=10.1007/978-3-319-74766-8_54|isbn=978-3-319-74765-1|access-date=2021-05-08|last2=Coffin|first2=Erica|editor2-last=Duggan|editor2-first=Michael|editor3-last=Chidambaran|editor3-first=Vidya|editor4-last=Venkata|editor4-first=Hari Prasad Krovvidi}}</ref>   
* <u>Spinal anesthesia</u>: Shorter acting agents including mepivicaine, chloroprocaine<ref>{{Cite journal|last=Goldblum|first=E.|last2=Atchabahian|first2=A.|date=2013|title=The use of 2-chloroprocaine for spinal anaesthesia: Chloroprocaine for spinal anaesthesia|url=http://doi.wiley.com/10.1111/aas.12071|journal=Acta Anaesthesiologica Scandinavica|language=en|volume=57|issue=5|pages=545–552|doi=10.1111/aas.12071|via=}}</ref>, or low-dose hyperbaric bupivicaine 0.75%. TNS symptoms may follow patients in the ambulatory settings after lithotomy position.<ref>{{Citation|last=Dalby|first=Patricia|title=Anesthesia for Medical Termination of Pregnancy|date=2018|url=http://link.springer.com/10.1007/978-3-319-74766-8_54|work=Anesthesiology|pages=527–534|editor-last=Goudra|editor-first=Basavana G.|place=Cham|publisher=Springer International Publishing|language=en|doi=10.1007/978-3-319-74766-8_54|isbn=978-3-319-74765-1|access-date=2021-05-08|last2=Coffin|first2=Erica|editor2-last=Duggan|editor2-first=Michael|editor3-last=Chidambaran|editor3-first=Vidya|editor4-last=Venkata|editor4-first=Hari Prasad Krovvidi}}</ref>  A T10-L1 sensory level is needed to provide anesthesia for intrauterine procedures.  Additionally, S2-S4 nerve root blockade is needed to blunt sensations to the vaginal canal (mediated by the pudendal nerve).


== Intraoperative management ==
== Intraoperative management ==
Line 67: Line 81:


* Standard ASA monitors
* Standard ASA monitors
* PIV


=== Induction and airway management<!-- Describe the important considerations and general approach to the induction of anesthesia and how the airway is typically managed for this case. --> ===
=== Induction and airway management<!-- Describe the important considerations and general approach to the induction of anesthesia and how the airway is typically managed for this case. --> ===


* Local anesthesia/sedation/neuroaxial: Monitor airway with end-tidal CO2 monitoring
* Local anesthesia/sedation/neuraxial: Monitor airway with end-tidal CO2 monitoring
* General Anesthesia (GA): May use LMA or ETT based upon aspiration risks (GA used for emotional distress, request, ongoing hemorrhage, sepsis, or hemodynamic instability<ref>{{Citation|last=Coffman|first=John C.|title=Anesthesia for Non-delivery Obstetric Procedures|date=2018|url=http://link.springer.com/10.1007/978-3-319-74766-8_52|work=Anesthesiology|pages=497–515|editor-last=Goudra|editor-first=Basavana G.|place=Cham|publisher=Springer International Publishing|language=en|doi=10.1007/978-3-319-74766-8_52|isbn=978-3-319-74765-1|access-date=2021-05-08|last2=Herndon|first2=Blair H.|last3=Thakkar|first3=Mitesh|last4=Fiorini|first4=Kasey|editor2-last=Duggan|editor2-first=Michael|editor3-last=Chidambaran|editor3-first=Vidya|editor4-last=Venkata|editor4-first=Hari Prasad Krovvidi}}</ref>)
* General Anesthesia (GA): May use LMA or ETT based upon aspiration risks (GA used for emotional distress, request, ongoing hemorrhage, sepsis, or hemodynamic instability<ref name=":1">{{Citation|last=Coffman|first=John C.|title=Anesthesia for Non-delivery Obstetric Procedures|date=2018|url=http://link.springer.com/10.1007/978-3-319-74766-8_52|work=Anesthesiology|pages=497–515|editor-last=Goudra|editor-first=Basavana G.|place=Cham|publisher=Springer International Publishing|language=en|doi=10.1007/978-3-319-74766-8_52|isbn=978-3-319-74765-1|access-date=2021-05-08|last2=Herndon|first2=Blair H.|last3=Thakkar|first3=Mitesh|last4=Fiorini|first4=Kasey|editor2-last=Duggan|editor2-first=Michael|editor3-last=Chidambaran|editor3-first=Vidya|editor4-last=Venkata|editor4-first=Hari Prasad Krovvidi}}</ref>)


=== Positioning<!-- Describe any unique positioning considerations, including potential intraoperative position changes. If none, this section may be removed. --> ===
=== Positioning<!-- Describe any unique positioning considerations, including potential intraoperative position changes. If none, this section may be removed. --> ===


* Dorsal lithotomy with stirrups
* Dorsal lithotomy with stirrups
* Arms out
* Slight Trendelenburg


=== Maintenance and surgical considerations<!-- Describe the important considerations and general approach to the maintenance of anesthesia, including potential complications. Be sure to include any steps to the surgical procedure that have anesthetic implications. --> ===
=== Maintenance and surgical considerations<!-- Describe the important considerations and general approach to the maintenance of anesthesia, including potential complications. Be sure to include any steps to the surgical procedure that have anesthetic implications. --> ===


* Cervical dilation during the start of the procedure may induce a vasovagal response with bradycardia and decreased cardiac output.  
* Cervical dilation during the start of the procedure may induce a vasovagal response with bradycardia and decreased cardiac output.  
* If GA, consider keeping MAC < 1.0 to reduce risk of uterine atony


=== Emergence<!-- List and/or describe any important considerations related to the emergence from anesthesia for this case. --> ===
=== Emergence<!-- List and/or describe any important considerations related to the emergence from anesthesia for this case. --> ===


* Monitor for PONV
* Monitor for PONV (high risk demographic)


== Postoperative management ==
== Postoperative management ==
Line 106: Line 124:
* Cervical laceration (< 1%)
* Cervical laceration (< 1%)


== Procedure variants<!-- This section should only be used for cases with multiple approaches (e.g. Laparoscopic vs. open appendectomy). Otherwise, remove this section. Use this table to very briefly compare and contrast various aspects between approaches. Add or remove rows as needed to maximize relevance. Consider using symbols rather than words when possible (e.g. +, –, additional symbols such as ↑ and ↓ are available using the "Ω" tool in the editor). --> ==
== Procedure variants*<!-- This section should only be used for cases with multiple approaches (e.g. Laparoscopic vs. open appendectomy). Otherwise, remove this section. Use this table to very briefly compare and contrast various aspects between approaches. Add or remove rows as needed to maximize relevance. Consider using symbols rather than words when possible (e.g. +, –, additional symbols such as ↑ and ↓ are available using the "Ω" tool in the editor). --> ==


{| class="wikitable"
{| class="wikitable"
|+
|+
<nowiki>*</nowiki>A Cochrane review compared trials assessing the anesthetic technique for evacuation of an incomplete miscarriage (general vs. regional vs. sedation).  There was a high level of heterogeneity among existing studies, and the authors concluded that choice of anesthetic technique should be influenced by other considerations, such as availability, effectiveness, safety, practitioner and patient preference.<ref>{{Cite journal|last=Calvache|first=Jose Andres|last2=Delgado-Noguera|first2=Mario F|last3=Lesaffre|first3=Emmanuel|last4=Stolker|first4=Robert J|date=2012-04-18|editor-last=Cochrane Pregnancy and Childbirth Group|title=Anaesthesia for evacuation of incomplete miscarriage|url=http://doi.wiley.com/10.1002/14651858.CD008681.pub2|journal=Cochrane Database of Systematic Reviews|language=en|doi=10.1002/14651858.CD008681.pub2}}</ref>
!
!
!Regional
!Regional
!Sedation
!Sedation
!Neuroaxial
!Neuraxial
!General Anesthesia
!General Anesthesia
|-
|-
Line 163: Line 182:
|-
|-
|Postoperative disposition
|Postoperative disposition
|
|Ambulatory
|
|Ambulatory
|
|PACU
|
|PACU
|-
|-
|Pain management
|Pain management
Line 180: Line 199:


Vasovagal response
Vasovagal response
|
|Unprotected airway and
|
 
aspiration risk in advanced
 
pregnancies
|Transient Neurologic
 
Symptoms (TNS)
|
|
|}
|}
Line 188: Line 213:


[[Category:Surgical procedures]]
[[Category:Surgical procedures]]
<references />
[[Category:Obstetric and gynecologic surgery]]

Latest revision as of 00:35, 5 April 2022

Dilation and curettage
Anesthesia type

General, MAC, neuraxial, or regional

Airway

Noninvasive O2 (for sedation, regional, or neuraxial) LMA/ETT if GA

Lines and access

PIV

Monitors

Standard

Primary anesthetic considerations
Preoperative

Anxiety

Intraoperative

Vasovagal response during cervical dilation

Postoperative

Hemorrhage Infection Cervical lacerations Uterine perforation

Article quality
Editor rating
In development
User likes
0

Dilation and curettage, also known as D&C, is a commonly performed procedure in obstetrics and gynecology which refers to dilation of the cervix in order to introduce instruments into the uterus, with a curette being used to empty or sample the endometrial cavity.

The indication for a D&C may be diagnostic or therapeutic. Diagnostic D&C has largely been replaced by an office endometrial biopsy. However, certain scenarios, including (but not limited to) the inability to tolerate office biopsy due to pain or anxiety, insufficient sampling, the need to exclude endometrial cancer, and cervical stenosis, may necessitate an operative diagnostic D&C over office endometrial biopsy[1].

Indications for therapeutic D&C in the pregnant patient are: elective termination of pregnancy (< 14 weeks gestational age), treatment of early pregnancy failure (missed or incomplete spontaneous abortion), evacuation of suspected molar pregnancy, treatment for cervical stenosis, and removal of suspected retained products of conception in the post-partum period.[1]

Therapeutic D&C may be indicated as a temporizing measure in the non-pregnant patient with abnormal uterine bleeding[2].

Preoperative management

Patient evaluation

System Considerations
Airway
Neurologic
Cardiovascular Hemodynamic instability due to uterine bleeding or possibly septic from retained products of conception
Pulmonary
Gastrointestinal If the patient was pregnant, you may need aspiration precautions depending on how many weeks pregnant
Hematologic Uncontrolled uterine bleeding
Renal
Endocrine
Other Emotional distress

Labs and studies

  • CBC
  • coagulation studies
  • blood type and antibody screen, possible crossmatching[3]

Operating room setup

  • If high-risk for uterine bleeding, consider having Oxytocin (Pitocin), Methylergonovine (Methergine), and/or Carboprost tromethamine (Hemabate) available.

Patient preparation and premedication

  • Special considerations for evacuation of molar pregnancy: hyperemesis gravidarum, preeclampsia, anemia, hyperthyroid, trophoblastic embolization, cardiorespiratory distress; may require additional pre-operative optimization or post-operative monitoring[3]
  • Anxiolysis: D&C for miscarriage or termination of pregnancy can be highly anxiety provoking and may instigate severe emotional distress prior to the the procedure.
  • Consider pre-operative acetaminophen.

Regional and neuraxial techniques

  • Paracervical or intracervical block: Lidocaine 1% can be injected by the obstetrician in 5mL aliquots to facilitate passage through the cervix and instrumentation of the uterus. Note that this does not block sensation for the manipulation and instrumentation of the vaginal canal. Patients who could not tolerate an intra-office procedure may also require sedation in addition to block placement.
  • Spinal anesthesia: Shorter acting agents including mepivicaine, chloroprocaine[4], or low-dose hyperbaric bupivicaine 0.75%. TNS symptoms may follow patients in the ambulatory settings after lithotomy position.[5] A T10-L1 sensory level is needed to provide anesthesia for intrauterine procedures. Additionally, S2-S4 nerve root blockade is needed to blunt sensations to the vaginal canal (mediated by the pudendal nerve).

Intraoperative management

Monitoring and access

  • Standard ASA monitors
  • PIV

Induction and airway management

  • Local anesthesia/sedation/neuraxial: Monitor airway with end-tidal CO2 monitoring
  • General Anesthesia (GA): May use LMA or ETT based upon aspiration risks (GA used for emotional distress, request, ongoing hemorrhage, sepsis, or hemodynamic instability[3])

Positioning

  • Dorsal lithotomy with stirrups
  • Arms out
  • Slight Trendelenburg

Maintenance and surgical considerations

  • Cervical dilation during the start of the procedure may induce a vasovagal response with bradycardia and decreased cardiac output.
  • If GA, consider keeping MAC < 1.0 to reduce risk of uterine atony

Emergence

  • Monitor for PONV (high risk demographic)

Postoperative management

Disposition

  • Fast-track discharge
  • Post-anesthesia care unit

Pain management

  • Oral or IV acetaminophen
  • Low dose IV narcotics
  • ± ketorolac

Potential complications

  • Peroneal nerve injury from lithotomy and stirrup position
  • Infection (1-2%)
  • Hemorrhage
  • Uterine perforation (0.63%). More common in pregnant patients with increasing gestational age[6]
  • Cervical laceration (< 1%)

Procedure variants*

*A Cochrane review compared trials assessing the anesthetic technique for evacuation of an incomplete miscarriage (general vs. regional vs. sedation). There was a high level of heterogeneity among existing studies, and the authors concluded that choice of anesthetic technique should be influenced by other considerations, such as availability, effectiveness, safety, practitioner and patient preference.[7]
Regional Sedation Neuraxial General Anesthesia
Unique considerations Medical termination

in early gestational age

or missed/incomplete

abortion

Consider for advanced

gestation or anticipated

patient discomfort

Consider for emotional distress,

ongoing hemorrhage, hemodynamic

instability, retention of placental

products requiring uterine relaxation

Position Lithotomy with

stirrups

Lithotomy with

stirrups

Lithotomy with

stirrups

Lithotomy with

stirrups

Surgical time 5-20min 5-20min 5-20min 5-20min
EBL 50-100mL 50-100mL 50-100mL 50-100mL
Postoperative disposition Ambulatory Ambulatory PACU PACU
Pain management
Potential complications Local anesthetic toxicity

Patient discomfort

Vasovagal response

Unprotected airway and

aspiration risk in advanced

pregnancies

Transient Neurologic

Symptoms (TNS)

References

  1. 1.0 1.1 Cooper, Danielle B.; Menefee, Gary W. (2021), "Dilation and Curettage", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID 33760550, retrieved 2021-05-08
  2. "Committee Opinion No. 557: Management of Acute Abnormal Uterine Bleeding in Nonpregnant Reproductive-Aged Women". Obstetrics & Gynecology. 121 (4): 891–896. April 2013. doi:10.1097/01.AOG.0000428646.67925.9a. ISSN 0029-7844.
  3. 3.0 3.1 3.2 Coffman, John C.; Herndon, Blair H.; Thakkar, Mitesh; Fiorini, Kasey (2018), Goudra, Basavana G.; Duggan, Michael; Chidambaran, Vidya; Venkata, Hari Prasad Krovvidi (eds.), "Anesthesia for Non-delivery Obstetric Procedures", Anesthesiology, Cham: Springer International Publishing, pp. 497–515, doi:10.1007/978-3-319-74766-8_52, ISBN 978-3-319-74765-1, retrieved 2021-05-08
  4. Goldblum, E.; Atchabahian, A. (2013). "The use of 2-chloroprocaine for spinal anaesthesia: Chloroprocaine for spinal anaesthesia". Acta Anaesthesiologica Scandinavica. 57 (5): 545–552. doi:10.1111/aas.12071.
  5. Dalby, Patricia; Coffin, Erica (2018), Goudra, Basavana G.; Duggan, Michael; Chidambaran, Vidya; Venkata, Hari Prasad Krovvidi (eds.), "Anesthesia for Medical Termination of Pregnancy", Anesthesiology, Cham: Springer International Publishing, pp. 527–534, doi:10.1007/978-3-319-74766-8_54, ISBN 978-3-319-74765-1, retrieved 2021-05-08
  6. "Practice Bulletin No. 135: Second-Trimester Abortion". Obstetrics & Gynecology. 121 (6): 1394–1406. 2013. doi:10.1097/01.AOG.0000431056.79334.cc. ISSN 0029-7844.
  7. Calvache, Jose Andres; Delgado-Noguera, Mario F; Lesaffre, Emmanuel; Stolker, Robert J (2012-04-18). Cochrane Pregnancy and Childbirth Group (ed.). "Anaesthesia for evacuation of incomplete miscarriage". Cochrane Database of Systematic Reviews. doi:10.1002/14651858.CD008681.pub2.