Does Deep Neuromuscular Blockade Improve Operating Conditions During Total Hip Replacements?
| Status: | Completed |
|---|---|
| Conditions: | Orthopedic |
| Therapuetic Areas: | Orthopedics / Podiatry |
| Healthy: | No |
| Age Range: | 50 - 75 |
| Updated: | 7/8/2018 |
| Start Date: | May 1, 2017 |
| End Date: | May 1, 2018 |
During many surgeries, increased muscle tension makes it harder for the surgeon to expose the
site of surgery and work within the incision. Neuromuscular blockade (NMB) drugs such as
Vecuronium bind to neurotransmitter (acetyl choline) receptors at the neuromuscular junction,
blocking their action and producing muscle relaxation. This muscle relaxation allows easier
retraction of muscle tissues and manipulation of structures in the wound. Improved surgical
conditions are likely to result in improved patient outcomes. While increased depths of NMB
have been shown to optimize surgical conditions during intra-abdominal and retroperitoneal
procedures, the impact of NMB depth has not been reported for orthopedic surgeries.1 To
address this, we propose to study the effect of NMB depth on surgical conditions during total
hip replacement (THR).
site of surgery and work within the incision. Neuromuscular blockade (NMB) drugs such as
Vecuronium bind to neurotransmitter (acetyl choline) receptors at the neuromuscular junction,
blocking their action and producing muscle relaxation. This muscle relaxation allows easier
retraction of muscle tissues and manipulation of structures in the wound. Improved surgical
conditions are likely to result in improved patient outcomes. While increased depths of NMB
have been shown to optimize surgical conditions during intra-abdominal and retroperitoneal
procedures, the impact of NMB depth has not been reported for orthopedic surgeries.1 To
address this, we propose to study the effect of NMB depth on surgical conditions during total
hip replacement (THR).
Specific Aims
1. Assess difference in surgical conditions between moderate and deep NMB groups. Enrolled
patients will be randomized to receive moderate (n=58) or deep (n=58) NMB. Difference in
surgical conditions will be evaluated by:
1. The number of requests from the surgeon for additional relaxation (NMB) during the
procedure. At any time during the operation if the surgeon feels the muscle tension
is interfering with ease of operation he will ask for additional muscle relaxation.
If the patient is moderately relaxed they will be converted to deep relaxation with
additional muscle relaxants. If they are already deeply relaxed no additional
relaxants will be administered (as is our current practice). All requests will be
recorded.
2. Rating by the surgeon after each surgery using an internally developed satisfaction
scale. The scale was developed by modifying a scale used in a previous study of
muscle relaxation in intra-abdominal surgery1 to specify two key elements
identified by our surgeon: ease of muscle retraction and femur manipulation.
2. Assess the impact of deep vs moderate NMB on time of surgery, measured from the time of
incision to joint reduction.
SIGNIFICANCE If we identify improved surgical conditions with deeper relaxation we will
incorporate deep NMB into our routine anesthesia practice for THR.
Vecuronium will be used as NMB drug in all study patients; this agent is currently used in
over 90% of THR cases at Maine Medical Center (MMC). As is currently routine Vecuronium will
be given after initiation of general anesthesia with propofol to facilitate intubation and
further doses of Vecuronium will be given throughout the case as noted below to maintain NMB
at the desired depth until the femoral implant is reduced. After the intubating dose of
Vecuronium, NMB depth will be monitored every 5 minutes and dosing will be adjusted as needed
to maintain a constant depth of NMB according to our current routine practice.
Group 1: Moderate NMB: Intubating dose of Vecuronium of 0.1 mg/kg (IBW) and re-dosing with
0.0125 to 0.05 mg/kg as needed to achieve and maintain 1 to 2 train of four (TOF)
contractions. Redosing in this manner is a current clinical practice.
Group 2: Deep NMB: Intubating dose of Vecuronium of 0.2 mg/kg (IBW) and re-dosing with 0.025
to 0.1 mg/kg to achieve and maintain zero twitches in the TOF, and post tetanic count (PTC)
of 1 to 2 contractions. This level of blockade is new to the practice since approval of the
drug for use at MMC but is in common use since the advent of Sugammadex.
The surgeon may request additional relaxation at anytime for inadequate surgical conditions
thought to be related to muscle tension. All requests will be recorded. Patients in the
moderate NMB group will receive additional doses of vecuronium to achieve deep NMB (PTC of 1-
2). In the deep NMB group with PTC of 1-2, a saline dose without NMB will be given.
NMB reversal Sugammadex will be given for reversal of NMB after the prosthesis has been
reduced, using routine dosing of 2 mg/kg for the moderate group and 4 mg/kg for the deep
group, per package insert by Merck.
1. Assess difference in surgical conditions between moderate and deep NMB groups. Enrolled
patients will be randomized to receive moderate (n=58) or deep (n=58) NMB. Difference in
surgical conditions will be evaluated by:
1. The number of requests from the surgeon for additional relaxation (NMB) during the
procedure. At any time during the operation if the surgeon feels the muscle tension
is interfering with ease of operation he will ask for additional muscle relaxation.
If the patient is moderately relaxed they will be converted to deep relaxation with
additional muscle relaxants. If they are already deeply relaxed no additional
relaxants will be administered (as is our current practice). All requests will be
recorded.
2. Rating by the surgeon after each surgery using an internally developed satisfaction
scale. The scale was developed by modifying a scale used in a previous study of
muscle relaxation in intra-abdominal surgery1 to specify two key elements
identified by our surgeon: ease of muscle retraction and femur manipulation.
2. Assess the impact of deep vs moderate NMB on time of surgery, measured from the time of
incision to joint reduction.
SIGNIFICANCE If we identify improved surgical conditions with deeper relaxation we will
incorporate deep NMB into our routine anesthesia practice for THR.
Vecuronium will be used as NMB drug in all study patients; this agent is currently used in
over 90% of THR cases at Maine Medical Center (MMC). As is currently routine Vecuronium will
be given after initiation of general anesthesia with propofol to facilitate intubation and
further doses of Vecuronium will be given throughout the case as noted below to maintain NMB
at the desired depth until the femoral implant is reduced. After the intubating dose of
Vecuronium, NMB depth will be monitored every 5 minutes and dosing will be adjusted as needed
to maintain a constant depth of NMB according to our current routine practice.
Group 1: Moderate NMB: Intubating dose of Vecuronium of 0.1 mg/kg (IBW) and re-dosing with
0.0125 to 0.05 mg/kg as needed to achieve and maintain 1 to 2 train of four (TOF)
contractions. Redosing in this manner is a current clinical practice.
Group 2: Deep NMB: Intubating dose of Vecuronium of 0.2 mg/kg (IBW) and re-dosing with 0.025
to 0.1 mg/kg to achieve and maintain zero twitches in the TOF, and post tetanic count (PTC)
of 1 to 2 contractions. This level of blockade is new to the practice since approval of the
drug for use at MMC but is in common use since the advent of Sugammadex.
The surgeon may request additional relaxation at anytime for inadequate surgical conditions
thought to be related to muscle tension. All requests will be recorded. Patients in the
moderate NMB group will receive additional doses of vecuronium to achieve deep NMB (PTC of 1-
2). In the deep NMB group with PTC of 1-2, a saline dose without NMB will be given.
NMB reversal Sugammadex will be given for reversal of NMB after the prosthesis has been
reduced, using routine dosing of 2 mg/kg for the moderate group and 4 mg/kg for the deep
group, per package insert by Merck.
Inclusion Criteria:
- American Society of Anesthesiologists (ASA) Physical status 1-3
- age 50-75
- English speaking
- able to provide informed consent
- BMI equal to less than 30
- non-emergent THR by anterolateral minimally invasive non-cemented total hip
arthroplasty
Exclusion Criteria:
- Revision surgery
- Bilateral THR
- ASA 4+
- age less than 50 or greater than 75
- BMI greater than 30
- unable to provide informed consent
- women taking oral contraceptives (Sugammadex used for reversal interferes with their
efficacy
- contraindications to general inhalation anesthesia (such as malignant hyperthermia)
- contraindications to NMB (known allergy to NMB)
- chronic kidney disease
We found this trial at
1
site
22 Bramhall St
Portland, Maine 04102
Portland, Maine 04102
(207) 662-0111
Principal Investigator: Craig Curry, MD
Phone: 207-662-2862
Maine Medical Center One of the country's consistently highest rated hospitals is right in your...
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