FRCA Notes

Fractured Neck of Femur

The March 2017 SAQ iteration of this topic was focussed wholly on pre-operative analgesia and the performance of a fascia iliac block.

The March 2023 CRQ (pass rate 67%) leant more heavily on the Association of Anaesthetists 2020 Guideline (see below).

Resources

  • Hip fracture is extremely common, and the incidence is rising
  • The majority of patients are female and ≥80yrs old

  • It is associated with a high mortality:
    • 30-day mortality can be as high as 10%, although short term mortality at 30 days (<1.5%) and 60-days (<5%) was lower in two recent trials
    • 1yr mortality can be has high as 35%

  • Mortality rate is greatly influence by perioperative care; the Hip Fracture Perioperative Network has been instituted to improve anaesthetic care

Perioperative management of the patient with a fractured neck of femure


Patient cohort

  • The patient cohort is elderly
  • There are high rates of pre-operative cognitive impairment and/or delirium

  • Multidisciplinary involvement is essential, with input from trauma surgeons, anaesthetists, orthogeriatricians and the wider MDT including PT, OT and nutrition teams

Analgesia

  • Surgery is the best analgesia, but this doesn't preclude use of other analgesics

  • Regular paracetamol
  • PRN opioids
  • Patients should have a single shot femoral nerve or fascia iliaca block in the Emergency Department
    • Ultrasound-guided placement increases accuracy and therefore adequacy of analgesia
    • They are not contra-indicated in anticoagulated patients
  • Benefits include reduced pain, reduced quadriceps spasm, reduced opioid administration and earlier re-mobilisation

Risk stratification

  • 70% of patients will be ASA 3 or 4, and patients with high risk should be identified early to optimise care
  • The widely-used Nottingham Hip Fracture Score (NHFS) has the highest sensitivity & specificity at 6 months, and explains the greatest proportion of variability in mortality at every time point (SAGE Open Med, 2020)
  • By comparison,the Age-Adjusted Charlson Comorbidity Index had higher sensitivity & specificity at 30 days and 12 months

  • The NHFS scores patients based on age, gender, AMTS, admission Hb, residence, number of comorbidities and whether they have active malignancy
  • Results correlate with 30-day mortality:
    • Total Score 30-day mortality
    0 0.9%
    1 1.5%
    2 2.4%
    3 3.8%
    4 6.2%
    5 9.8%
    6 15%
    7 23%
    8 33%
    9 47%
    10 57%

Investigations

  • Investigations should aim to identify optimisable factors:
    • FBC - manage anaemia with transfusion or non-transfusion techniques (e.g. iron)
      • Perioperative [Hb] should be 90g/L, or 100g/L if history of IHD or failure to mobilise first day post-operatively due to fatigue or dizziness
    • Renal function and electrolytes - provide adequate fluid resuscitation, limited pre-operative fasting
    • Inflammatory markers, urinalysis, CXR - treat suspected infection with antibiotics, chest physiotherapy etc.
    • ECG - facilitates rate control
    • Group and save - to facilitate perioperative transfusion if necessary
  • Some investigations may be indicated in particular patient groups e.g. clotting screen for those on oral anticoagulants
  • Others, namely TTE, should not delay surgery

Management of anticoagulants

  • 30 - 40% of those with #NOF are taking anticoagulant or antiplatelet medications pre-operatively
    • 2% are on DOACs
    • There is an increased risk of peri-operative transfusion in such patients, but no increased mortality

  • The risk of vertebral canal haematomas during neuraxial anaesthesia is very small (1:118,000) and probably less so in this patient population
  • However, there is a balance between the risks of spinal anaesthesia in anticoagulated patients vs. the risk of a general anaesthetic
  • The Asssociation Guidelines (see Resources) has a table, which is reproduced here:
Drug Elimination half-life Management Acceptable to proceed with spinal?
Aspirin Irreversible Proceed with surgery Yes
Clopidogrel Irreversible Proceed with surgery under GA
Monitor platelets ± transfusion		 Only if GA poses greater risk to patient
Ticagrelor 8 - 12hrs Proceed with surgery under GA
Monitor platelets ± transfusion		 Only if GA poses greater risk to patient
Unfractionated heparin 1 - 2hrs Stop IV heparin 2 - 4 h pre-op 4hrs post-infusion
LMWH 3 - 7hrs Last dose 12hrs (prophylactic) or 24hrs (therapeutic) pre-op 12hrs (prophylactic) - 24hrs (therapeutic) post-last dose
Warfarin 4 - 5days 5mg vit. K IV + repeat INR after 4hrs
± further vit. K ± PCC		 If INR <1.5
Dabigatran 15 - 17hrs Consider surgery 24 - 48hrs after last dose
± praxbind reversal		 At 24-36hrs if thrombin time normal or dabigatran assay <50ng.ml-1
If abnormal or assay >50ng.ml-1 then give Praxbind
Rivaroxiban
Edoxaban
Apixaban		 12hrs Consider surgery 12hrs (GA) - 24hrs (GA/RA) after last dose
± partial reversal with PCC		 24hrs if CrCl >30ml/min
48hrs if CrCl <30ml/min
Or proceed if assay <50ng.ml-1
Or reverse if assay >50ng.ml-1

Timing of surgery

  • Surgical outcomes are improved if surgery is performed within 36hrs of admission
  • Beyond 48hrs there are increases in morbidity and mortality from pneumonia, pressure sores and VTE
  • In many cases, the pain and immobility associated with delay contribute to poor outcomes to a greater extent than the benefit of correcting abnormalities
  • Delay should only occur if there is a realistic prospect of improving the patient's condition prior to surgery i.e. if the benefits outweigh the risks of delay
    • Logistical factors (lack of theatre space, lack of surgeon/anaesthetist), awaiting a TTE or minor electrolyte abnormalities are unacceptable reasons to delay
Category Acceptable reasons for delay
Respiratory Severe chest sepsis
Cardiac Uncontrolled or acute onset LV failure
Correctable tachyarrhythmia >120bpm
Electrolytes Na+ <120mmol/L or >150mmol/L
K+ <2.8mmol/L or >6mmol/L
Endocrine Uncontrolled diabetes (i.e. DKA or HHS)
Haemtological Hb <80g/L
Reversible coagulopathy


Choice of anaesthetic technique

  • In short, outcome data does not strongly support either spinal anaesthesia or GA being a superior technique (BJA, 2023)
  • It seems to me that whatever physiological impact RA or GA has, it's being lost in the maelstrom of the larger insult to these vulnerable patients

  • A 2016 Cochrane Review found spinal or GA did not significantly differ with respect to rates of:
    • 30-day mortality
    • Pneumonia, stroke, MI or delirium
    • VTE, so long as appropriate prophylaxis is prescribed (without it, spinal anaesthesia is associated with less VTE)

  • The two large trials of RA vs. GA from 2021 (RAGA and REGAIN) showed no significant differences in:
    • Incidence, duration, subtype or severity of delirium
    • Ability to walk unaided at 60 days
    • Duration of inpatient stay
    • 30-day or 60-day mortality

  • A meta-analysis (BJA, 2022) of fifteen trials comparing GA and RA, including the above two, found:
    • No significant difference in in-hopsital, 30-day, 60-day or 90-day mortality
    • No significant difference in rates of intra-operative hypotension, acute coronary syndrome, post-operative pneumonia, post-operative delirium
    • No significant difference in duration of hospital stay, be it on an orthopaedic ward or elsewhere
    • Spinal anaesthesia appears to reduce the risk of AKI vs. GA (RR 0.59) although the meta analysis came from only two trials

Spinal anaesthesia

  • One may wish to modify one's technique to reduce haemodynamic instability, which can be accomplished by:
    • Lower doses of IT bupivacaine
    • Using IT fentanyl to facilitate lower IT bupivacaine dose
    • Using heavy bupivacaine with fracture side down

Analgesia

  • Whether GA or spinal, all patients should have an ultrasound-guided fascia iliaca block (e.g. 40mls 0.375% levobupivacaine), which can occur from 6hrs post-previous block
  • Fracture reduction is often itself analgesic, with variable pain thereafter

Monitoring

  • AAGBI as standard
  • A-line if cardiac comorbidities
  • ± CVP/CO monitoring - goal-directed fluid therapy associated with shorter duration of stay
  • ± Depth of anaesthesia monitoring - may reduce haemodynamic effects of excessive anaesthesia and reduce POCD
  • ± Cerebral oxygen monitoring - may reduce POCD through recognition and management of intra-operative cerebral hypoxia

Surgical techniques

  • Extracapsular fractures are treated with conservation of the femoral head e.g. ORIF with a DHS
  • Intracapsular fractures are treated with replacement of the femoral head e.g. cemented or uncemented hemiarthroplasty (risk of BCIS)

  • Surgical time varies from 30mins - 120mins
  • Patients are either supine or lateral
    • There may be difficult access to patients supine on a hip table for DHS owing to the elevated table height

Haemorrhage

  • Blood loss is variable, depending on:
    • Fracture type - higher in comminuted and/or extracapsular fractures
    • Surgical skill and speed
    • Presence of altered coagulation
  • 1g TXA IV is routine
  • Perioperative point-of-care Hb measurements should be used

Haemodynamics

  • Avoid hypotension where possible, as it is associated progressively with 5-day and 30-day mortality
  • Target a MAP >70mmHg or SBP within 20% of pre-operative levels
  • Methods to help haemodynamics include:
    • Alterations to spinal technique (see above)
    • Metaraminol infusions, which are more reliable than boluses
    • Use of age-adjusted MAC (an AAGBI standard) ± nitrous oxide (anecdotal)
    • Use depth of anaesthesia monitoring to titrate anaesthesia effectively
    • Anticipate and manage cardio-respiratory instability during cementing

Care bundle

  • Maintain normothermia with active warming techniques; patients are prone to hypothermia
  • Meticulous approach to pressure care in this vulnerable population
  • IV antibiotics as per trust policy
  • PONV is less common in this age group and some anti-emetics (dexamethasone, cyclizine) are associated with post-operative delirium, so should be avoided

  • Early mobilisation is key to management and outcome

Anaemia

  • Anticipate a mean drop in [Hb] of 25g/L
  • One needs to balance the risks of:
    • Anaemia-related organ ischaemia (cerebral, renal, cardiac)
    • Immunosuppressive effects of blood transfusion
  • Aim [Hb] >90g/L

Analgesia

  • Surgery is the best analgesia and post-operative pain is mostly at the incision site
  • Simple analgesia ± opioids is often sufficient
  • Avoid NSAIDs as they increase risk of AKI
  • Care with opioids, especially morphine and tramadol; oxycodone may be preferable

Delirium

  • Assess for delirium using 4AT score
  • Avoid or limit drugs associated with increased post-operative delirium:
    • Ketamine
    • Benzodiazepines
    • Dexamethasone
    • Cyclizine
    • Anti-cholinergics

Complications

  • The most common post-operative complications and their risk factors are:
    • Pneumonia: pre-existing lung disease, age, oral steroid use
    • Cardiac failure: pre-existing cardiovascular disease, age, male gender

  • Pre-existing respiratory or renal disease are other risk factors which increase mortality