Table 10 Continuous infusion femoral nerve block versus placebo/no treatment: study details and qualitative outcomes

Study

n treatment/
control

Comparison

Supplemental

analgesic

VAS scores and type of pain, where specified

Time to first analgesic request

Use of supplemental analgesic

Other important outcomes

Edwards 1992

(LoE 1)

19/18

30 ml 0.25% bupivacaine into ipsilateral femoral nerve sheath after induction of anaesthesia, followed by continuous infusion of 0.125% bupivacaine at 6 ml/h for 24 h (Fem) vs. control (Cont)

Postop: IM papaveretum (10–20 mg) every 4 h, on request

Fem superior at the time points recorded (i.e. 4 and 24 h) (p<0.01, in both cases)

__

Number of papaveretum doses required in the 1^st 24 h: Fem superior (p<0.01); total papaveretum dose in the 1^st 24 h: Fem superior (p<0.01)

__

Hirst 1996

(LoE 1)

11/11

Pre-op 20 ml 0.5% bupivacaine and 1:200,000 epinephrine, postop continuous infusion 0.125% bupivacaine at 6 ml/h for 48 h (Fem) vs. “mock” femoral nerve blocks (Cont)

Postop: PCA-morphine, IV

Fem superior during passive flexion (30°) in recovery room (p<0.05); NS at other time points recorded (in the next 72 h)

__

Morphine requirements: NS during assessment period (i.e. over 1^st 48 h postop)

PONV

Nausea: Fem superior at 24 and 48 h (p values not reported)

Kaloul 2004 1^st arm

(LoE 1)

20/20

Continuous femoral block with 30 ml 0.5% ropivacaine and 1:200,000 epinephrine bolus, followed by infusion of 0.2% ropivacaine at 12 ml/h for 48 h (Fem) vs. control (Cont)

Postop: PCA-morphine, IV, for 48 h; additional oral analgesia: oxycodone, acetaminophen, codeine

At rest: Fem superior at 6 and 24 h (p<0.0001, in both cases), but NS at 48 h; during physical therapy: NS

__

0–48 h morphine consumption: Fem superior (p=0.0002)

__

Kaloul 2004 2nd arm

(LoE 1)

20/20

Continuous lumbar plexus block with 30 ml 0.5% ropivacaine and 1:200,000 epinephrine bolus, followed by infusion of 0.2% ropivacaine at 12 ml/h for 48 h (Lumb) vs. control (Cont)

Postop: PCA-morphine, IV, for 48 h; additional oral analgesia: oxycodone, acetaminophen, codeine

At rest: Lumb superior at 6 and 24 h (p<0.0001, in both cases), but NS at 48 h; during physical therapy: NS

__

0–48 h morphine consumption: Lumb superior (p<0.0001)

__

Ganapathy 1999

(LoE 1)

20/22/20

Modified continuous femoral block with 30 ml, followed by infusion at 10 ml/h for 48 h: 0.1% bupivacaine (LowBup) vs. 0.2% bupivacaine (HighBup) vs. saline (Cont)

Postop: PCA-morphine, IV

At rest and during activity: NS, except on day of surgery, when both LowBup and HighBup superior to Cont (p<0.05, in all cases)

__

Morphine consumption: HighBup superior to control (p<0.05) during first 4 h postop and from 8 am to 8 pm on day 1, but not during the night of surgery; total morphine consumption and hourly morphine use: NS

PONV

NS

Functional Outcomes

ROM: HighBup superior on day 1 only (p<0.05)

Serpell 1991

(LoE 2)

13/16

Postop lumbar plexus block with 0.3 ml/kg 0.5% bupivacaine, with additional doses at 6–8 h intervals (Fem) vs. control (Cont)

Postop: PCA-morphine,IV; additionally, 10 mg IM morphine and 1 g oral paracetamol was available if required

NS at the time points recorded (i.e. at 24 and 48 h)

__

0–48 h: Fem superior (p<0.05); additional analgesia (oral/IM): NS

PONV

NS

Singelyn 1998

(LoE 1)

15/15

Continuous femoral block with 37 ml 0.25% bupivacaine and 1:200,000 epinephrine, followed by infusion of 0.125% bupivacaine with0.1 ug/ml sufentanil and 1 ug/ml clonidine at 10 ml/h (Fem) vs. control (Cont)

Postop: 1 g IV paracetamol, followed by 10–20 mg IM piritramide if pain scores remained unchanged after 30 min

At rest: Fem superior at all time points (i.e. at 4, 24 and 48 h) (p<0.05, in all cases); on movement: Fem superior at 4 and 24 h (p<0.05, in both cases), but NS at 48 h

__

NS over 48 h postop

PONV

Nausea and/or vomiting: NS

Functional Outcomes

Flexion: Fem superior on day 1 (p=0.009), from day 2 to discharge (p<0.001) and at 6 weeks (p=0.03), but NS at 3 months; number of days required to obtain 90-degree flexion: Fem superior (p<0.001); number of patients discharged with <90-degree flexion: Fem superior (p=0.02); first ambulation: Fem superior (p=0.02)

Hospital stay

Length of hospital stay:

Fem superior (p<0.001)

*Study*	n treatment/ control	*Comparison*	*Supplemental* *analgesic*	*VAS scores and type of pain, where specified*	*Time to first analgesic request*	*Use of supplemental analgesic*	*Other important outcomes*
Edwards 1992 (LoE 1)	19/18	30 ml 0.25% bupivacaine into ipsilateral femoral nerve sheath after induction of anaesthesia, followed by continuous infusion of 0.125% bupivacaine at 6 ml/h for 24 h (Fem) *vs.* control (Cont)	Postop: IM papaveretum (10–20 mg) every 4 h, on request	Fem superior at the time points recorded (i.e. 4 and 24 h) (p<0.01, in both cases)	__	Number of papaveretum doses required in the 1^st 24 h: Fem superior (p<0.01); total papaveretum dose in the 1^st 24 h: Fem superior (p<0.01)	__
Hirst 1996 (LoE 1)	11/11	Pre-op 20 ml 0.5% bupivacaine and 1:200,000 epinephrine, postop continuous infusion 0.125% bupivacaine at 6 ml/h for 48 h (Fem) *vs.* “mock” femoral nerve blocks (Cont)	Postop: PCA-morphine, IV	Fem superior during passive flexion (30°) in recovery room (p<0.05); NS at other time points recorded (in the next 72 h)	__	Morphine requirements: NS during assessment period (i.e. over 1^st 48 h postop)	PONV Nausea: Fem superior at 24 and 48 h (p values not reported)
Kaloul 2004 1^st arm (LoE 1)	20/20	Continuous femoral block with 30 ml 0.5% ropivacaine and 1:200,000 epinephrine bolus, followed by infusion of 0.2% ropivacaine at 12 ml/h for 48 h (Fem) *vs.* control (Cont)	Postop: PCA-morphine, IV, for 48 h; additional oral analgesia: oxycodone, acetaminophen, codeine	At rest: Fem superior at 6 and 24 h (p<0.0001, in both cases), but NS at 48 h; during physical therapy: NS	__	0–48 h morphine consumption: Fem superior (p=0.0002)	__
Kaloul 2004 2nd arm (LoE 1)	20/20	Continuous lumbar plexus block with 30 ml 0.5% ropivacaine and 1:200,000 epinephrine bolus, followed by infusion of 0.2% ropivacaine at 12 ml/h for 48 h (Lumb) *vs.* control (Cont)	Postop: PCA-morphine, IV, for 48 h; additional oral analgesia: oxycodone, acetaminophen, codeine	At rest: Lumb superior at 6 and 24 h (p<0.0001, in both cases), but NS at 48 h; during physical therapy: NS	__	0–48 h morphine consumption: Lumb superior (p<0.0001)	__
Ganapathy 1999 (LoE 1)	20/22/20	Modified continuous femoral block with 30 ml, followed by infusion at 10 ml/h for 48 h: 0.1% bupivacaine (LowBup) vs. 0.2% bupivacaine (HighBup) *vs.* saline (Cont)	Postop: PCA-morphine, IV	At rest and during activity: NS, except on day of surgery, when both LowBup and HighBup superior to Cont (p<0.05, in all cases)	__	Morphine consumption: HighBup superior to control (p<0.05) during first 4 h postop and from 8 am to 8 pm on day 1, but not during the night of surgery; total morphine consumption and hourly morphine use: NS	PONV NS Functional Outcomes ROM: HighBup superior on day 1 only (p<0.05)
Serpell 1991 (LoE 2)	13/16	Postop lumbar plexus block with 0.3 ml/kg 0.5% bupivacaine, with additional doses at 6–8 h intervals (Fem) *vs.* control (Cont)	Postop: PCA-morphine,IV; additionally, 10 mg IM morphine and 1 g oral paracetamol was available if required	NS at the time points recorded (i.e. at 24 and 48 h)	__	0–48 h: Fem superior (p<0.05); additional analgesia (oral/IM): NS	PONV NS
Singelyn 1998 (LoE 1)	15/15	Continuous femoral block with 37 ml 0.25% bupivacaine and 1:200,000 epinephrine, followed by infusion of 0.125% bupivacaine with0.1 ug/ml sufentanil and 1 ug/ml clonidine at 10 ml/h (Fem) *vs.* control (Cont)	Postop: 1 g IV paracetamol, followed by 10–20 mg IM piritramide if pain scores remained unchanged after 30 min	At rest: Fem superior at all time points (i.e. at 4, 24 and 48 h) (p<0.05, in all cases); on movement: Fem superior at 4 and 24 h (p<0.05, in both cases), but NS at 48 h	__	NS over 48 h postop	PONV Nausea and/or vomiting: NS Functional Outcomes Flexion: Fem superior on day 1 (p=0.009), from day 2 to discharge (p<0.001) and at 6 weeks (p=0.03), but NS at 3 months; number of days required to obtain 90-degree flexion: Fem superior (p<0.001); number of patients discharged with <90-degree flexion: Fem superior (p=0.02); first ambulation: Fem superior (p=0.02) Hospital stay Length of hospital stay: Fem superior (p<0.001)