Total joint arthroplasty (TJA) is a successful surgical intervention to reduce pain and
immobility from osteoarthritis. Mortality rates following TJA are low and survival has
been increasing over the last two and a half decades despite an ageing population with a
higher frequency of comorbidities.
Perioperative virtual reality (VR) is a non-pharmacological technique which has been used
effectively to avoid sedative pre-medication, increase patient satisfaction and alleviate
procedural pain during nerve blocks. VR has been successfully utilised across different
medical specialties to reduce patient anxiety associated with interventions including
magnetic resonance imaging (MRI), physical therapy, dental pain, and change of burns
dressings. Furthermore, a trend towards less propofol sedation with use of VR has been
found in spinal anaesthetic for hip, knee and ankle operations, with no decrease in
patient satisfaction. However, this small pilot study did not investigate any other
outcomes other than type and amount of sedation and duration of surgery. VR use has also
been shown to reduce fentanyl dose, midazolam use and pain in elective total knee
arthroplasty (TKA) patients who received a pre-operative adductor canal catheter.
Satisfaction of patient, surgeon and anaesthetist has also been compared when using VR
and using sedation with midazolam in patients undergoing urologic surgery under spinal
anaesthesia. The patient and anaesthetist satisfaction scores were significantly higher
in the VR group than in the sedation group.
Sedation is associated with a number of post-operative complications including nausea,
hypo/hypertension, lower respiratory tract infection, cardiac arrhythmias, peripheral
nerve damage, and post-operative delirium (PD). Nausea is a common occurrence following
surgery with reported incidences of 30% in all post-surgical patients and up to 80% in
high-risk patients. Dose dependent hypotension is the common complication in patients who
have received propofol sedation, particularly in volume depleted patients. A common
cardiovascular complication during anaesthesia is arrhythmia, with 70% of patients having
arrhythmia undergoing general anaesthesia for various surgical procedures. Further
complications associated with propofol, although more uncommon, include
hypertriglyceridemia, pancreatitis and allergic complications.
The incidence of PD is generally higher after hip fracture surgery (4-53.3%) compared to
elective hip surgery (3.6-28.3%). Independent risk factors for developing inpatient
delirium include dementia, age, visual impairment, functional impairment and increased
comorbidities. While most studies measuring effect of propofol on sleep disturbance and
PD have focussed on the critical care setting, light propofol sedation (to target a
bispectral index (BIS) >80) decreased the prevalence of PD by 50% compared to deep
sedation (BIS target of 50) in patients undergoing hip surgery with spinal anaesthesia. A
further RCT investigated whether limiting propofol sedation with spinal anaesthesia in
non-elective hip fracture repair patients reduced risk of delirium post-operatively.
Patients were randomised to receive either heavier sedation (modified observer's
assessment of alertness/sedation score (OAA/S) of 0-2) or lighter sedation (OAA/S of
4-5). There were no significant differences in risk of incident delirium between the
heavier and lighter sedation groups. However, when stratified by Charlson comorbidity
index (CCI), in low comorbid states, heavier sedation levels doubled the risk of delirium
compared to lighter sedation. This randomised controlled trial (RCT) recruited hip
fracture patients with a mean age of 82 years. Therefore, a similar study should be
conducted in younger, less comorbid patients undergoing elective joint arthroplasty.
Sedation can also affect recovery following surgery. Being male, nausea, vomiting and
pain during the ward stay have been reported to be risk factors for poor quality of
recovery after sedation with midazolam for lower limb orthopaedic surgeries. Poor quality
of recovery following surgery can also increase hospital stay and health care resources.
No significant difference in quality of recovery has been reported between those who
experienced immersive VR and those who underwent conventional care.
Propofol infusions are commonly administered alongside spinal anaesthesia for orthopaedic
surgery. It is commonly given with no specific objective clinical target end point. This
gives rise to the potential of administering excess propofol which may result in
inadvertent deep levels of sedation. This can cause prolonged periods of inadvertent
general anaesthesia depth during 'regional' cases (often without insertion of an airway
device). Therefore, it is important to investigate potential ways of lowering propofol
infusions during surgery, without increasing patient risk, anxiety or pain, such as
through the use of VR.
Aims of Study
The aims of this pilot study are to determine:
the feasibility of using VR during TKA with spinal anaesthesia.
what outcomes, if any, can be influenced using VR during TKA with spinal
anaesthesia.