Review question
Cochrane authors wanted to find out how effective different methods (interventions) are in reducing the amount and severity of shoulder pain following gynaecological keyhole surgery.
Background
Gynaecological keyhole surgery (laparoscopy) is a procedure where a surgeon uses a camera (laparoscope) to see inside the lower abdomen to view the uterus (womb), fallopian tubes and ovaries. They can also use special instruments to do tests or treat certain gynaecological conditions. This is a common procedure that about 250,000 women in the UK have each year. Up to 80% of these women may experience shoulder-tip pain (STP), which may be very painful and lead to longer stays in hospital and even having to go back in to hospital.
During the laparoscopy, the surgeon puts gas (carbon dioxide) into the patient’s abdomen (pneumoperitoneum). This inflates the abdomen so that the surgeon can see the organs in the abdominal cavity and can carry out surgery. It is possible that inflating the abdomen stimulates a nerve that runs from the top of the abdomen (diaphragm) up to the shoulders and neck, which causes STP.
We looked at several ways surgeons try to reduce STP: putting local anaesthetic (pain killer) directly into the abdominal cavity or diaphragm; using warmed carbon dioxide, sometimes with moisture added to it (humidified) during surgery; removing gas from the abdominal cavity with drains; replacing gas with fluid (fluid instillation) or forcing gas out of the abdominal cavity at the end of the procedure by increasing the pressure at which patients were made to breathe whilst still under anaesthetic (PRM).
Study characteristics
Our evidence comes from 32 randomised controlled trials (clinical studies where people are randomly put into one of two or more treatment groups) with 3284 women from 11 countries. The trials compared different ways of reducing the incidence (number of times STP occurred) or severity of STP in women undergoing gynaecological laparoscopy. The evidence is up to date to 8 August 2018.
Key results
Women having gynaecological laparoscopy may have less STP or need fewer pain killers following several interventions: a specific technique for releasing the pneumoperitoneum; leaving fluid or local anaesthetic (liquid pain killers) in the abdomen or putting a drain from the inside to the outside of the abdomen for a period of time.
There is low to moderate-quality evidence that the following interventions may not make a difference to the incidence or severity of STP: local anaesthetic (liquid pain killers) placed only in the upper part of the abdomen underneath the diaphragm; warmed and moistened carbon dioxide gas.
There is low-quality evidence that gasless laparoscopy may increase the severity of STP, compared with standard treatment.
Few studies reported side effects (adverse events) and some potentially useful interventions have not been studied by RCTs of gynaecological laparoscopy.
We are cautious about these results because the evidence from the studies that we found was not good quality (low to moderate-quality evidence).
Quality of the evidence
The studies in this review did not use the best methods to gather and report their evidence and we thought the evidence was only low to moderate quality. This means that we cannot be very confident in the results.
There is low to moderate-quality evidence that the following interventions are associated with a reduction in the incidence or severity, or both, of STP, or a reduction in analgesia requirements for women undergoing gynaecological laparoscopy: a specific technique for releasing the pneumoperitoneum; intraperitoneal fluid instillation; an intraperitoneal drain; and local anaesthetic applied to the peritoneal cavity (not subdiaphragmatic).
There is low to moderate-quality evidence that subdiaphragmatic intraperitoneal local anaesthetic and warmed and humidified insufflating gas may not make a difference to the incidence or severity of STP.
There is low-quality evidence that gasless laparoscopy may increase the severity of STP, compared with standard treatment.
Few studies reported data on adverse events. Some potentially useful interventions have not been studied by RCTs of gynaecological laparoscopy.
Laparoscopy is a common procedure used to diagnose and treat various gynaecological conditions. Shoulder-tip pain (STP) as a result of the laparoscopy occurs in up to 80% of women, with potential for significant morbidity, delayed discharge and readmission. Interventions at the time of gynaecological laparoscopy have been developed in an attempt to reduce the incidence and severity of STP.
To determine the effectiveness and safety of methods for reducing the incidence and severity of shoulder-tip pain (STP) following gynaecological laparoscopy.
We searched the following databases: Cochrane Gynaecology and Fertility (CGF) Specialised Register, the Cochrane Central Register of Studies Online (CRSO), MEDLINE, Embase, PsycINFO and CINAHL from inception to 8 August 2018. We also searched the reference lists of relevant articles and registers of ongoing trials.
Randomised controlled trials (RCTs) of interventions used during or immediately after gynaecological laparoscopy to reduce the incidence or severity of STP.
We used standard methodological procedures expected by Cochrane. Primary outcomes: incidence or severity of STP and adverse events of the interventions; secondary outcomes: analgesia usage, delay in discharge, readmission rates, quality-of-life scores and healthcare costs.
We included 32 studies (3284 women). Laparoscopic procedures in these studies varied from diagnostic procedures to complex operations. The quality of the evidence ranged from very low to moderate. The main limitations were risk of bias, imprecision and inconsistency.
Specific technique versus "standard" technique for releasing the pneumoperitoneum
Use of a specific technique of releasing the pneumoperitoneum (pulmonary recruitment manoeuvre, extended assisted ventilation or actively aspirating intra-abdominal gas) reduced the severity of STP at 24 hours (standardised mean difference (SMD) -0.66, 95% confidence interval (CI) -0.82 to -0.50; 5 RCTs; 670 participants; I2 = 0%, low-quality evidence) and reduced analgesia usage (SMD -0.53, 95% CI -0.70 to -0.35; 4 RCTs; 570 participants; I2 = 91%, low-quality evidence). There appeared to be little or no difference in the incidence of STP at 24 hours (odds ratio (OR) 0.87, 95% CI 0.41 to 1.82; 1 RCT; 118 participants; low-quality evidence).
No adverse events occurred in the only study assessing this outcome.
Fluid instillation versus no fluid instillation
Fluid instillation is probably associated with a reduction in STP incidence (OR 0.38, 95% CI 0.22 to 0.66; 2 RCTs; 220 participants; I2 = 0%, moderate-quality evidence) and severity (mean difference (MD) (0 to 10 visual analogue scale (VAS) scale) -2.27, 95% CI -3.06 to -1.48; 2 RCTs; 220 participants; I2 = 29%, moderate-quality evidence) at 24 hours, and may reduce analgesia usage (MD -12.02, 95% CI -23.97 to -0.06; 2 RCTs; 205 participants, low-quality evidence).
No study measured adverse events.
Intraperitoneal drain versus no intraperitoneal drain
Using an intraperitoneal drain may reduce the incidence of STP at 24 hours (OR 0.30, 95% CI 0.20 to 0.46; 3 RCTs; 417 participants; I2 = 90%, low-quality evidence) and may reduce analgesia use within 48 hours post-operatively (SMD -1.84, 95% CI -2.14 to -1.54; 2 RCTs; 253 participants; I2 = 90%). We are uncertain whether it reduces the severity of STP at 24 hours, as the evidence was very low quality (MD (0 to 10 VAS scale) -1.85, 95% CI -2.15 to -1.55; 3 RCTs; 320 participants; I2 = 70%).
No study measured adverse events.
Subdiaphragmatic intraperitoneal local anaesthetic versus control (no fluid instillation, normal saline or Ringer’s lactate)
There is probably little or no difference between the groups in incidence of STP (OR 0.72, 95% CI 0.42 to 1.23; 4 RCTs; 336 participants; I2 = 0%; moderate-quality evidence) and there may be no difference in STP severity (MD -1.13, 95% CI -2.52 to 0.26; 1 RCT; 50 participants; low-quality evidence), both measured at 24 hours. However, the intervention may reduce post-operative analgesia use (SMD-0.57, 95% CI -0.94 to -0.21; 2 RCTs; 129 participants; I2 = 51%, low-quality evidence).
No adverse events occurred in any study.
Local anaesthetic into peritoneal cavity (not subdiaphragmatic) versus normal saline
Local anaesthetic into the peritoneal cavity may reduce the incidence of STP at 4 to 8 hours post-operatively (OR 0.23, 95% CI 0.06 to 0.93; 2 RCTs; 157 participants; I2 = 56%; low-quality evidence). Our other outcomes of interest were not assessed.
Warmed, or warmed and humidified CO2 versus unwarmed and unhumidified CO2
There may be no difference between these interventions in incidence of STP at 24 to 48 hours (OR 0.81 95% CI 0.45 to 1.49; 2 RCTs; 194 participants; I2 = 12%; low-quality evidence) or in analgesia usage within 48 hours (MD -4.97 mg morphine, 95% CI -11.25 to 1.31; 1 RCT; 95 participants; low-quality evidence); there is probably little or no difference in STP severity at 24 hours (MD (0 to 10 VAS scale) 0.11, 95% CI -0.75 to 0.97; 2 RCTs; 157 participants; I2 = 50%; moderate-quality evidence).
No study measured adverse events.
Gasless laparoscopy versus CO2 insufflation
Gasless laparoscopy may be associated with increased severity of STP within 72 hours post-operatively when compared with standard treatment (MD 3.8 (0 to 30 VAS scale), 95% CI 0.76 to 6.84; 1 RCT; 54 participants, low-quality evidence), and there may be no difference in the risk of adverse events (OR 2.56, 95% CI 0.25 to 26.28; 1 RCT; 54 participants; low-quality evidence).
No study measured the incidence of STP.