DOS BULLETIN - Dansk Ortopædisk Selskab

2010-378_DOS nr. 3 2010 29/09/10 10:08 Side 120
Ortostatic intolerance during early mobilization after
total hip arthroplasty
Øivind Jans, Søren Solgaard, Morten Bundgaard-Nielsen,
Pär I. Johansson, Henrik Kehlet
Section of Surgical Pathophysiology, Rigshospitalet; Department of
Orthopedic Surgery, Hørsholm Hospital; Section of Surgical Pathophysiology,
Rigshospitalet; Capital Region Blood Bank, Rigshospitalet
Background: Early postoperative mobilization is a cornerstone in fasttrack
hip arthroplasty (THA). However, postoperative orthostatic intolerance
(OI) may delay early recovery or lead to complications. OI have
been attributed to impaired fluid balance, postoperative anaemia or the
use of opioid analgesics. However, the prevalence of OI or the association
between OI and these factors has not been established after THA
Purpose: We evaluated the orthostatic function and cardiovascular
responses to mobilization before and after surgery in fast-track THA
patients.
Methods: Orthostatic tolerance was evaluated in 26 patients scheduled
for THA and undergoing spinal anaesthesia, before, 6 and 24 hours after
surgery. An opioid sparing analgesic regime was administered. Systolic
(SAP)- and diastolic (DAP) arterial pressure, heart rate (HR) and cardiac
output (CO) were measured non-invasively using the Nexfin® system
and cerebral (ScO2) and muscular (SmO2) tissue oxygenation were
recorded using non- infrared spectroscopy (Invos®).
Findings: No patients demonstrated OI before surgery, whereas 11
(42%) and 5 (19%) patients had OI 6 and 24 hours after surgery, respectively.
3 (12%) patients had ortostatic hypotension, but no symptoms of
OI 6 hours after surgery. Before surgery, SAP, DAP and HR increased (P
< 0.05) while CO remained stable upon standing. At 6 and 24 hours after
surgery SAP, DAP, CO and ScO2 decreased (P < 0.05) in patients with
OI but remained stable in patients without OI. There were no association
between postoperative Hb or opioid use and OI.
Conclusion: Early postoperative OI is common after THA and is associated
with a diminished cardiovascular response to standing and
decreased cerebral oxygenation. Further research on OI after THA
should focus on fluid dynamics and haemodynamic adaptation to early
mobilization.
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