You have been asked to assess a 76-year-old male, scheduled to have a verv large incisional hernia repaired electively. He has a history of obstructive sleep apnoea (OSA) requiring nocturnal continuous positive airway pressure (CPAP). A recent echocardiogram, done to evaluate pedal oedema and newly diagnosed elevated creatinine, has revealed an ejection fraction of 55%, a right ventricular systolic pressure RVSP of 90 mmH , and moderate tricuspid regurgitation (TR). He has a history of recurrent deep venous thrombosis (DVT) and pulmonary embolism (PE) due to deficiency of Factor V Leiden and is currently on Rivaroxaban.
a) List the specific risks associated with his co-morbidities in the perioperative period.
(40% marks)
b) Outline strategies that could be used to minimize these risks in the perioperative period.
(60% marks)
a)
OSA:
• Acute respiratory failure,
• Cardiac arrhythmias,
• Cardiac ischaemia including cardiac arrest
• Risk of exacerbation by opiates may make analgesic management difficult
Pulm hypertension:
• Acute right heart failure during perioperative period related to hypoxia and pain, Severe hypoxaemia,
• Cardiac dysrhythmias,
• Renal failure
Renal dysfunction:
• Fluid overload,
• Electrolyte and acid base imbalance,
• Altered drug metabolism
DVTs, PE, Factor V Leiden deficiency:
• High risk of thrombotic events esp PE with exacerbation of RHF.
Anticoagulation:
• Bleeding risk,
• Thrombotic risk if ceased and not adequately covered.
b)
Preop:
• Consider need for surgery,
• Consider timing of surgery o Surgery should be done when co-morbidities are optimised
o Organisational factors: Surgery should be conducted when ICU support available, experienced surgical and anaesthetic team available, early on list (so not cancelled), in hospital with appropriate support (ICU and usual physicians)
• May be relevant to discuss goals of therapy with patient, surgical team and pre-existing physicians
• Optimise cardiac status especially with respect to pulmonary hypertension,? need for pulmonary vasodilators. Cardiology input would be valuable
• Optimise respiratory status especially with respect to nocturnal NIV; settings, interface
• Plan anticoagulation over perioperative period.
• OK to mention IVC filter if recent PE. But not necessary
• Optimise renal function; may need renal consult and exclusion of reversible causes
• Liase with surgeon, anaesthetist, treating physicians regarding management plan
Intra-operative
• Use of regional techniques / local blocks to reduce requirement for systemic analgesia
• Appropriate monitoring and lines
Post-operative If intubated:
o Early extubation and early mobilisation to avoid atelectasis if possible o Consider role of extubation to NIV o Continue usual nocturnal NIV
• Consider opiate sparing analgesic regimen, consider regional techniques (will need to consider anticoagulation issues)
o Avoid NSAIDS due to renal dysfunction
• Avoid fluid overload
o Maintain vascular tone with low dose noradrenaline
o Consider vasopressin if high dose pressor required due to less effect on pulmonary vasculature
• Restart anticoagulation as soon as safe, in keeping with pre-operative plan o Consider surveillance duplex monitoring if > 24-48hours off anticoagulation
• Avoid nephrotoxic medications
Organise follow-up with usual physicians on discharge to the ward.
a)
Lets list the problems and consider the risks associated with them, in order of their appearance.
| Problem | Risks |
| Expected extensive abdominal procedure |
|
| OSA on CPAP |
|
| Pulmonary hypertension |
|
| Factors V Leiden deficiency |
|
| Anticoagulation with DOAC |
|
b)
To mitigate some of these risks, the following strategies may be considered:
| Risk | Strategy |
|
Increased risk of post-op atelectasis |
|
|
Significant analgesia requirements |
|
|
Long complex procedure |
|
|
Prolonged recovery from anaesthetic |
|
|
OSA: Propensity to somnolence and hypoxia with sedatives |
|
|
Worsening of pulmonary hypertension |
|
|
Thrombophilia and anticoagulation |
|
Interestingly, the college recommends to avoid fluid overload. That's probably accurate as the term "overload" implies "excessive load", which is by definition bad. You should avoid excessive bad fluid loading. But, the term "adequate fluid resuscitation" is good. Or at least adequate. Gille et al (2014) recommended the use of a "restrictive" strategy, guided by TOE or PA catheter.
Gross, Jeffrey B., et al. "Practice guidelines for the perioperative management of patients with obstructive sleep apnea: a report by the American Society of Anesthesiologists Task Force on Perioperative Management of patients with obstructive sleep apnea." Anesthesiology 104.5 (2006): 1081.
Donahue, Brian S. "Factor V Leiden and perioperative risk." Anesthesia & Analgesia 98.6 (2004): 1623-1634.
Gille, Jochen, et al. "Perioperative anesthesiological management of patients with pulmonary hypertension." Anesthesiology research and practice 2012 (2012).