Results of the search

We identified 1218 studies of which 96 had relevant titles and abstracts. We excluded 10 of these studies (Agostini 2008; Allen 2006; Allen 2009; Cansino 2009; Habersetzer 1972; Harper 1997; Karasahin 2011; Manyou 2008; Naki 2011; Phittayawechwiwat 2007) (see Characteristics of excluded studies). We excluded 70 studies in total (Figure 3). We found no ongoing trials. Titles and abstracts were unclear in three studies (Chaudhuri 1980; Regina 1987; Sen 1980) and we put them into 'Studies awaiting classification'. We identified 26 relevant studies with 28 comparisons as Kan 2004 and Sharma 2009 studied more than two groups (see Characteristics of included studies), involving a total of 2790 women, that were published in full. Our full search results are in Figure 3.

Figure 3

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Searching results

Included studies

In our original review we included 17 studies. In this updated review we included nine new studies (Al‐Sunaidi 2007; Amirian 2009; Chudnoff 2010; Lazenby 2009; Lopez 2007; Mankowski 2009; Renner 2012; Sharma 2009; Thongrong 2011) making a total of 26 studies. Two of the new studies compared paracervical block versus placebo (Amirian 2009; Chudnoff 2010) making a total of 10 studies. We included three additional studies (Lopez 2007; Sharma 2009; Thongrong 2011) of paracervical block versus sedation and systemic analgesia; two additional studies (Al‐Sunaidi 2007; Mankowski 2009) versus other regional techniques; and one additional study versus no treatment (Renner 2012). We did not find any studies of paracervical block versus general anaesthesia.

Excluded studies

In our original review, we excluded 80 studies.

In our updated review we excluded an additional 10 newly identified studies (Agostini 2008; Allen 2006; Allen 2009; Cansino 2009; Habersetzer 1972; Harper 1997; Karasahin 2011; Manyou 2008; Naki 2011; Phittayawechwiwat 2007). We then re‐evaluated the studies we had excluded in our previous review. We removed 18 studies from the list of excluded studies as they were not RCTs (Amyot‐Legault 1981; Coker 1968; Fernandez 1997; Ferry 1994; Formiga‐Filho 1974; Gad 1967; Lewis 1971; Littlepage 1969; Readman 2004; Reguer Noriega 1973; Rotchell 1976; Sandmire 1974; Santonja 1974; Strausz 1971; Thonneau 1998; Toth 2000; Van Praagh 1967; Walden 1973).

Allocation

We judged 17 studies to have a low risk of bias for random sequence generation (Al‐Sunaidi 2007; Amirian 2009; Carroll 2005; Chanrachakul 2001; Chudnoff 2010; Cicinelli 1998; Egziabher 2002; Glantz 2001; Gómez 2004; Guida 2003; Kan 2004; Lau 1999; Lopez 2007; Mankowski 2009; Renner 2012; Sharma 2009; Vercellini 1994). There was an unclear risk of bias in seven studies (Buppasiri 2005; Chatfield 1970; Lazenby 2009; Miller 1996; Mola 1996; Titapant 2003; Yazaci 2003), and a high risk of bias in two studies (Finikiotis 1992; Thongrong 2011). We judged allocation concealment to be low risk of bias in 14 studies (Amirian 2009; Carroll 2005; Chanrachakul 2001; Chudnoff 2010; Cicinelli 1998; Glantz 2001; Gómez 2004; Kan 2004; Lau 1999; Lazenby 2009; Lopez 2007; Mankowski 2009; Mola 1996; Renner 2012), unclear in six studies (Buppasiri 2005; Egziabher 2002; Guida 2003; Miller 1996; Titapant 2003; Yazaci 2003), and at a high risk of bias in six studies (Al‐Sunaidi 2007; Chatfield 1970; Finikiotis 1992; Sharma 2009; Thongrong 2011; Vercellini 1994).

Blinding

Of the 26 studies, 15 adequately blinded women to their allocated intervention (Amirian 2009; Chanrachakul 2001; Chatfield 1970; Chudnoff 2010; Cicinelli 1998; Egziabher 2002; Glantz 2001; Gómez 2004; Kan 2004; Lau 1999; Lazenby 2009; Mankowski 2009; Miller 1996; Renner 2012; Titapant 2003). Nine studies adequately blinded treatment providers to the allocated intervention (Amirian 2009; Chanrachakul 2001; Chatfield 1970; Cicinelli 1998; Egziabher 2002; Glantz 2001; Lau 1999; Miller 1996; Titapant 2003). Thirteen studies adequately blinded outcome assessors to the allocated intervention (Amirian 2009; Chanrachakul 2001; Chatfield 1970; Chudnoff 2010; Cicinelli 1998; Egziabher 2002; Glantz 2001; Gómez 2004; Kan 2004; Lau 1999; Miller 1996; Renner 2012; Titapant 2003). Three of these studies (Chatfield 1970; Cicinelli 1998; Glantz 2001) blinded assessors to outcomes other than abdominal pain.

Incomplete outcome data

All studies completed follow up for all women. Seven studies were at high risk of incomplete outcome data (Al‐Sunaidi 2007; Amirian 2009; Buppasiri 2005; Chanrachakul 2001; Chatfield 1970; Chudnoff 2010; Cicinelli 1998; Kan 2004; Lau 1999; Lazenby 2009); risk of attrition bias was unclear in two (Finikiotis 1992; Mola 1996), and low in 17 studies (Carroll 2005; Egziabher 2002; Glantz 2001; Guida 2003; Gómez 2004; Kan 2004; Lau 1999; Lazenby 2009; Lopez 2007; Mankowski 2009; Miller 1996; Renner 2012; Sharma 2009; Thongrong 2011; Titapant 2003; Vercellini 1994; Yazaci 2003).

Selective reporting

Of the 26 studies, 24 were free of selective reporting (Al‐Sunaidi 2007; Amirian 2009; Buppasiri 2005; Chanrachakul 2001; Chatfield 1970; Chudnoff 2010; Cicinelli 1998; Egziabher 2002; Finikiotis 1992; Glantz 2001; Gómez 2004; Guida 2003; Kan 2004; Lau 1999; Lazenby 2009; Lopez 2007; Mankowski 2009; Miller 1996; Mola 1996; Sharma 2009; Thongrong 2011; Titapant 2003; Vercellini 1994; Yazaci 2003), one was unclear (Carroll 2005), and one was at high risk (Renner 2012) (see Figure 1, Figure 2).

Other potential sources of bias

Two studies (Kan 2004; Lazenby 2009) presented the trust fund information. Sample size calculations were presented in 14 studies (Chanrachakul 2001; Chudnoff 2010; Cicinelli 1998; Egziabher 2002; Glantz 2001; Gómez 2004; Guida 2003; Kan 2004; Lau 1999; Lazenby 2009; Lopez 2007; Renner 2012; Thongrong 2011; Vercellini 1994). Amirian 2009 excluded the participants who had uterine perforation or severe bleeding during curettage after the allocation concealment was performed. We judged one study to be unclear of other potential biases (Al‐Sunaidi 2007).

Paracervical local anaesthesia versus placebo

(Analysis 1.1 to Analysis 1.9)
Ten studies compared paracervical block versus placebo (Amirian 2009; Chanrachakul 2001; Chatfield 1970; Chudnoff 2010; Cicinelli 1998; Egziabher 2002; Glantz 2001; Lau 1999; Miller 1996; Titapant 2003). Uterine interventions included hysteroscopy, endometrial biopsy, fractional curettage, and vacuum aspiration. The local anaesthetics used were lidocaine, chloroprocaine, and xylocaine (see Characteristics of included studies for details).

Pain during speculum insertion (Analysis 1.1)

There was no evidence of an effect of paracervical block, SMD 0.20 (95% CI ‐0.35 to 0.74).

Pain on tenaculum placement (Analysis 1.2)

There was no evidence of an effect of paracervical block, MD ‐0.70 (95% CI ‐2.26 to 0.86).

Pain dilating cervix (Analysis 1.3)

There was evidence that paracervical block reduced the pain of cervical dilatation, SMD ‐0.39 (95% CI ‐0.72 to ‐0.07).

Pain during uterine interventions (Analysis 1.4)

There was evidence that paracervical block reduced the pain of uterine interventions (carbon dioxide insufflation, endometrial biopsy, fractional curettage, suction evacuation, or aspiration), SMD ‐0.74 (95% CI ‐1.19 to ‐0.28). However, there was substantial heterogeneity across these subgroups (I² = 85%, P < 0.0001). Within the subgroups there was evidence of an effect for endometrial biopsy and suction aspiration (SMD ‐1.71, 95% CI ‐2.26 to ‐1.17; and SMD ‐0.90, 95% CI ‐1.47 to ‐0.32 respectively).

Pain during uterine interventions (risk of pain) (Analysis 1.5, Analysis 1.6)

There was evidence that paracervical block reduced the risk of severe pain but not any pain (RR 0.16, 95% CI 0.04 to 0.74; RR 0.87, 95% CI 0.68 to 1.12 respectively). Chanrachakul 2001 reported that paracervical block significantly reduced the median pain score during fractional curettage, from 6.0 to 4.0 (statement unsupported by a P value). There was no evidence of an effect in a study of tubal insert placement (Chudnoff 2010) (see Additional Table 1, Appendix 4).

Postoperative pain (Analysis 1.7)

There was no evidence that paracervical block reliably reduced postoperative pain (see also Appendix 5, Appendix 6, Appendix 7).

Shoulder pain (Analysis 1.8)

There was no evidence that paracervical block reduced the risk of shoulder pain.

Adverse effects (Analysis 1.9)

Paracervical block did not change the risk of sweating, nausea or vomiting. In one study (Lau 1999) the risk of hypotension after paracervical block was greater than after placebo injection, RR 3.06 (95% CI 1.21 to 7.78). In Miller 1996 3/27 women developed symptoms consistent with lidocaine toxicity (tingling lips, dizziness).

Additional drug requirement

There was no evidence that paracervical block reduced the need for additional drugs, including general anaesthesia (Amirian 2009) (see Appendix 8, Appendix 9).

Paracervical local anaesthesia versus no anaesthesia

(Analysis 2.1)

Six studies compared paracervical block versus no treatment (Carroll 2005; Gómez 2004; Kan 2004; Lazenby 2009; Renner 2012; Vercellini 1994). In two studies women had a hysteroscopy (Carroll 2005; Vercellini 1994) and in four studies women had suction termination or evacuation of incomplete miscarriages (Gómez 2004; Kan 2004; Lazenby 2009; Renner 2012).

Pain during the procedure

Meta‐analysis was not performed for this outcome. Kan 2004 and Lazenby 2009 found no evidence that paracervical block reduced median pain scores during or after suction termination under sedation when compared to no block. Gómez 2004 reported no difference in intraoperative pain as recalled 10 minutes after the procedure (Appendix 10). There was no evidence for significant differences in pain during hysteroscopy and endometrial biopsy in Vercellini 1994 (Additional Table 2), but Renner 2012 reported different results on pain reduction (Additional Table 2). This study found that baseline pain and pain on speculum insertion were not significantly different between paracervical local anaesthesia and no treatment (Appendix 11, Appendix 12). Pain during paracervical injection was greater in the paracervical local anaesthesia group (Appendix 13) but pain on cervical dilation and aspiration was significantly lower with paracervical local anaesthesia than with no treatment (Appendix 14, Appendix 15).

Postoperative pain (Analysis 2.1)

There was no evidence that paracervical block reduced postoperative pain (also see Appendix 16).

Adverse effects

No study found evidence for differences in the risks of adverse effects.

Patient satisfaction

Kan 2004 did not find evidence for differences in patient satisfaction. Renner 2012 found that paracervical block increased the median satisfaction with pain control and with the procedure (73 versus 49, P < 0.01; and 90 versus 84, P = 0.04 respectively).

Requirement of additional analgesia

There was no evidence that paracervical block affected this outcome (Renner 2012).

Paracervical local anaesthesia versus other regional anaesthesia

(Analysis 3.1 to Analysis 3.3)

Five studies (Al‐Sunaidi 2007; Finikiotis 1992; Kan 2004; Mankowski 2009; Yazaci 2003) compared paracervical block to other local anaesthetic techniques: uterosacral block (Finikiotis 1992), intracervical block (Al‐Sunaidi 2007; Kan 2004; Mankowski 2009), and intrauterine topical analgesia (Yazaci 2003).

Pain during cervical dilatation (Analysis 3.1)

There was no evidence that paracervical block affected this outcome.

Pain during uterine intervention (Analysis 3.2)

Statistically, the studies were too heterogeneous to summate. There was no evidence that paracervical block reduced severe pain, moderate or severe pain during hysteroscopy (Finikiotis 1992) (RR 0.17, 95% CI 0.42 to 3.27; and RR 1.22, 95% CI 0.80 to 1.85 respectively), see Appendix 17. Yazaci 2003 reported that intrauterine instillation of local anaesthetic caused worse pain than paracervical block, SMD 9.49 (95% CI 4.20 to 14.78) (Appendix 18). There was no evidence that pain was different during suction termination under sedation with paracervical block versus intracervical block (Kan 2004), or during hysteroscopy (Al‐Sunaidi 2007) or uterine curettage (Mankowski 2009). Paracervical block slightly reduced pain during endometrial biopsy compared with intrauterine local anaesthetic installation, MD on a 100‐point scale of 6.9 (95% CI 2.5 to 11.3, P = 0.002) (Yazaci 2003), see Additional Table 3.

Postoperative pain at different times (Analysis 3.3)

The studies were statistically too heterogeneous to summate. Paracervical block reduced postoperative pain in two studies (MD 4.63, 95% CI 0.24 to 9.02 (Yazaci 2003); and MD 0.40, 95% CI 0.29 to 0.51 (Al‐Sunaidi 2007) at 10 minutes, MD 0.70, 95% CI 0.61 to 0.79 at 30 minutes, and MD 0.20, 95% CI 0.13 to 0.27 at 60 minutes postoperation) (see Appendix 19).

Adverse effects

Yazaci 2003 did not find any difference in the risk of a vasovagal reaction (Appendix 20).

Paracervical local anaesthesia versus systemic analgesia

(Analysis 4.1 to Analysis 4.3)

Six studies (Buppasiri 2005; Guida 2003; Lopez 2007; Mola 1996; Sharma 2009; Thongrong 2011) compared paracervical block with systemic analgesics and sedatives: mefenamic acid (Buppasiri 2005); fentanyl and midazolam (Guida 2003); paracervical block plus diclofenac and meperidine plus diclofenac (Lopez 2007); pethidine and diazepam (Mola 1996); drotaverine with mefenamic acid and diazepam with pentazocine (Sharma 2009); and intravenous morphine (Thongrong 2011). The studies included women undergoing: fractional curettage (Buppasiri 2005; Thongrong 2011); hysteroscopy (Guida 2003); manual vacuum aspiration (Lopez 2007); bi‐manual removal of retained placenta (Mola 1996); hysteroscopy with endometrial biopsy (Sharma 2009).

Pain during uterine intervention (Analysis 4.1)

The studies were statistically too heterogeneous to summate. There was no evidence that pain during uterine intervention differed with paracervical block compared to systemic analgesia (also see Appendix 21 and Appendix 22).

Postoperative pain (Analysis 4.2)

Statistically the studies were too heterogeneous to summate. There was no evidence that pain after uterine intervention differed with paracervical block compared with systemic analgesia (also see Appendix 23).

Adverse effects (Analysis 4.3)

There was no evidence that the rates of pallor, hypotension, dizziness, or nausea or vomiting differed with paracervical block compared with systemic analgesia.

Requirement for postoperative analgesia

There was no evidence that the rates or doses of postoperative analgesics differed with paracervical block versus systemic analgesia. Buppasiri 2005 reported that three patients in each group needed additional drugs (intravenous pethidine). Guida 2003 and Lopez 2007 reported no significant difference in postoperative analgesic requirement between paracervical block and systemic analgesia (Appendix 24).

Patient satisfaction

There was no evidence for a difference in this outcome (see Appendix 25, Appendix 26).

Paracervical local anaesthesia versus general anaesthesia

We found no studies for this comparison.

Subgroup analysis

We did not perform any subgroup analysis because of the small number of included studies, and no data were available on potential factors for subgroup analysis.

Sensitivity analysis

We did not do sensitivity analyses because few studies were included in the review.