The Influence of Body-mass Index on the Outcome of Spinal Anesthesia for Total Knee Replacement Arthroplasty

In these prospective observational study, the investigators are trying to evaluate (1) the influence of body-mass index on spinal anesthetic outcome and (2) the determinants on spinal anesthetic outcome by logistic regression analysis.

Study Overview

• Status: Completed
• Conditions: Spinal Anesthesia; Success or Failure of Spinal Anesthesia
• Intervention / Treatment: Drug: Spinal anesthesia (heavy bupivacaine)

Detailed Description

Although the spread of spinal anesthetic drug is unpredictable, patients factors (age, gender, height,weight, body-mass index), spinal anatomy, anesthetic drug dose, and lumbosacral cerebrospinal fluid volume are known to be the determinants of sensory block level. Among these determinants, the influence of body-mass index (BMI) on spinal anesthesia is controversial, and there is no specific guideline showing the relative priority of these determinants.

Therefore, in these prospective observational study, the investigators are trying to evaluate (1) the influence of body-mass index on spinal anesthetic outcome and (2) the relative influence of these determinants on spinal anesthetic outcome by logistic regression analysis.

• Study Type: Observational
• Enrollment (Actual): 209

Contacts and Locations

Study Locations

• Korea, Republic of
  • Seoul, Korea, Republic of, 135-710
    • Samsung Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients who are undergoing spinal anesthesia in Samsung Medical Center during study period

Description

Inclusion Criteria:

• Patients who are undergoing spinal anesthesia in Samsung Medical Center during study period
• American Society of Anesthesiologist Physical Status classification I ~ III

Exclusion Criteria:

• Bupivacaine allergy
• medical history of spinal surgery
• Diabetic neuropathy
• active infection at the lumbosacral area
• other contraindication of spinal anesthesia

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Obese group; patients with BMI >= 30.0 kg/m2 who received spinal anesthesia with heavy marcaine	Drug: Spinal anesthesia (heavy bupivacaine); Spinal anesthesia with heavy bupivacaine of 6, 7, 8, 9, 10, 11 mg; Other Names: Spinal anesthesia; heavy bupivacaine
Non-obese group; patients with BMI < 30.0 kg/m2 who received spinal anesthesia with heavy marcaine	Drug: Spinal anesthesia (heavy bupivacaine); Spinal anesthesia with heavy bupivacaine of 6, 7, 8, 9, 10, 11 mg; Other Names: Spinal anesthesia; heavy bupivacaine

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
spinal anesthetic success/ failure	when (1) a bilateral T12 sensory block to pinprick within 15 minutes of intrathecal drug administration with sensory/motor block scale ≥ 2 and (2) the level of sensory block at the end of surgery was higher than or equal to T12 with sensory/motor block scale ≥ 2.	at 2 hour after the anesthetic induction

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peak level of sensory block at anesthesia induction	Sensory block levels determined by pinprick test	during 20 min after anesthetic induction
Spinal anesthesia sensory/motor block level at the end of surgery	Spinal anesthesia block level as determined by Pinprick sensory test with Bromage scale. Sensory 0 = an ability to appreciate a pinprick as sharp; 1 = perception of a pinprick as less sharp than in unblocked areas; 2 = perception of a pinprick as touch but not sharp (analgesia); 3 = an inability to feel pinprick(anesthesia). Bromage Scale 0 = ability to lift an extended knee at the hip; 1 = ability to flex the knee but not to lift an extended leg; 2 = ability to flex toes only; 3 = inability to move.	2 hours after induction (at the end of surgery)
the incidence of tourniquet pain	the incidence of tourniquet pain during the tourniquet time reported by the patient (NRS >= 2)	at 90 min afer anesthetic induction
Incidence of hypotension, bradycardia	Incidence of hypotension, bradycardia total dose of ephedrine Lowest mean blood pressure Incidence of vomiting, shivering	during 2 hours after anesthesia induction

Collaborators and Investigators

• Sponsor: Samsung Medical Center
• Investigators: Principal Investigator: Ji Sun Hahm, MD, Samsung Medical Center

Study record dates

Study Major Dates

• Study Start: May 1, 2012
• Primary Completion (Actual): December 1, 2012
• Study Completion (Actual): December 1, 2012

Study Registration Dates

• First Submitted: May 29, 2012
• First Submitted That Met QC Criteria: May 31, 2012
• First Posted (Estimate): June 1, 2012

Study Record Updates

• Last Update Posted (Estimate): October 30, 2014
• Last Update Submitted That Met QC Criteria: October 29, 2014
• Last Verified: October 1, 2014

More Information

Terms related to this study

• Keywords: Spinal anesthesia; duration; determinant
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Sensory System Agents; Anesthetics, Local; Anesthetics; Bupivacaine
• Other Study ID Numbers: 2012-04-089-001