This study investigated the risk of inpatient falls after total knee arthroplasty (TKA) based on the type of anesthesia used. The study used a database of over 191,000 TKA procedures from 400 US hospitals between 2006-2010. It found an overall fall rate of 1.6%, higher than previously reported. General anesthesia alone was associated with a 1.6% fall rate, compared to 1.3% for neuraxial anesthesia and 1.5% for combined neuraxial and general. Peripheral nerve blocks did not significantly impact the risk of falls. Older patients and those with more comorbidities were at higher risk of falls. While neuraxial anesthesia was associated with lower odds of falls than general anesthesia alone, peripheral

1. Journal Club
Dr John Slattery

2. Article
 Potentially preventable
 Significant morbidity & mortality
  risk due to limited perioperative mobility
 Peripheral nerve block speculated to  risk
 Hypothesis – Older & sicker patients at  risk of
falls & choice of anaesthesia/nerve blocks will
affect this risk

3. Methods
 Database (Premier Perspective Inc):
 January 2006 – September 2010
 400 acute care US hospitals
 Demographics, hospital characteristics, billing
info, ICD-9, procedural codes
 Standardised validation process – 7 step
analysis & 100 crosschecks
 Missing data in 28% of cases
 Inclusion – TKA & anaesthesia info (from
billing)
 Routine admissions & elective procedures

4. Methods
 Primary outcome – Inpatient falls
 Not standardised (ICD-9 “accidents
occurring in a residential institution”)
 ?Follow-up period
 Limited variables e.g. comorbidities
 191,570 records:
 10.9% - neuraxial block
 12.9% - combined neuraxial & GA
 76.2% - GA

5. Results
 1.6% fall rate (previously reported 0.85%)
 Older – 68.9 years vs 66.3 years
 GA – 1.6% (NA 1.3%, combined 1.5%)
  comorbidities
 12.1% received peripheral nerve block
 No difference in age/sex/comorbidity
burden
 No significant difference between
proportion falling with peripheral block &
without

6. Multiple logistical regression

7. Comorbidities

8. Complications

9. Conclusion
 1.6% fell
  reporting/aging population
 Inpatient falls associated with worse
outcomes
 Population suffering from falls were older,
male & with more comorbidities
 Reduced motor strength
 Impaired reflexes/balance
 Less willing to ask for help
 More risky/overestimate abilities

10. Conclusion
 Falls associated with various
comorbidities
 Altered sensorium/perceptions
(OSA/psycosis)
 Neuraxial anaesthesia lower odds of falls
compared with GA alone (30% risk )
 Less influence on postoperative cognitive
function & delirium
 Peripheral nerve blocks had no significant
impact on the risk of falls


11. Limitations
 Retrospective case-control study
 Selection bias
 Database with missing information despite
validity checks
 Restricted to elective procedures
 Definition of inpatient falls non-standardised
(PPV of inpatient falls from ICD-9 coding =
54%)
 Limited variables e.g comorbidities –
Neurological disease
 No distinction made between impact of
different types of peripheral nerve block,
doses used etc.

12. Limitations
 ?Alternate practice
 10.9% neuraxial anaesthesia
 No difference in comorbidity burden between
peripheral blockade & non-blockade
 No causal relationships can be made from the
data
 Any falls prevention techniques used in each
hospital
 Insufficient power to comment on the role of
peripheral nerve block

13. References
 Memtsoudis S, Danninger T, Rasul R, et
al. Inpatient Falls after Total Knee
Arthroscopy. The Role of Anesthesia Type
and Peripheral Nerve Blocks.
Anesthesiology, 2014; 120: 551-563.

14. Questions?