Table 3.

Patient-controlled analgesia

Author	Study population and design	Outcome
Zelcer et al., 1992[27]	Prospective study in 80 women comparing physician-administered and patient- controlled alfentanil administration	The average drug requirement (1.49±0.50 and 1.46±0.55 µg/kg/min) and post-operative complications were similar in both groups. Patient comfort and satisfaction were better with PCA
Cook et al., 1993[28]	Prospective randomised study where 25 patients received propofol and 22 patient received midazolam	PCA with midazolam and propofol were compared. Alfentanil was administered on demand. Onset of sedation took 70.6 s (SD 22.4) in the propofol group and 106.3 s (SD 50.7) in the midazolam group. Procedure was completed successfully and none of the patients required additional sedation
Bhattacharya et al., 1997[29]	Prospective randomised study with 39 women in the PCA group and 42 women in the PAS group	Pain score was less and patient satisfaction was better in the PCA group when compared to the PAS group, whereas fentanyl utilization was significantly more in the PCA group
Thompson et al., 2000[30]	Randomised controlled trial where 57 women received PCA with isodesox (1% desflurane, 0.25% isoflurane and 60% oxygen in nitrogen) and 55 women received IV fentanyl	The mean pain score was significantly lesser in the TIVA group (P=0.02), whereas a fall in oxygen saturation of less than 94% was seen in around 29% of women who received TIVA when compared to 1.7% in the PCA group
Lok et al., 2002[15]	Prospective randomised trial in 106 patients. Patient-controlled sedation (n=51), Physician-administered sedation (n=55)	Level of sedation and co-operation was similar in both group PCS using propofol and alfentanil and PAS using diazepam and pethidine. Pain score was higher during and two h post-procedure (53±23 vs. 35±24, P<0.01 and 29±27 vs. 17±22, P <0.05, respectively) in the PCS group. Although patient satisfaction was similar in both groups, physician satisfaction was better with PAS
Lier et al., 2015[31]	Randomised control trial involving 76 women Forty women received pethidine and midazolam-induced conscious sedation and 36 women received PCA with remifentanil and diclofenac	Pain score during the procedure was comparable for remifentanil and pethidine groups (4 [3-7] vs. 6 [4-8], P=0.13), whereas pain score was significantly lower in the CSA group (1 [0–3] vs. 2 [1–5], P=0.016). Reproductive and safety outcomes were similar, though patient satisfaction was better in the PCA group

PCA=Patient controlled analgesia, PAS=Physician-administered sedation, PCS=Patient-controlled sedation, TIVA=Total intravenous anaesthesia, SD=Standard deviation