High Flow Nasal Oxygen & Length of Stay

The enthusiasm for high flow nasal oxygen continues unabated. This study was on high‐risk patients with pre‐existing lung disease (COPD, asthma, recent lower respiratory tract infection), heavy smokers or morbidly obese patients (body mass index (BMI) ≥ 35 kg.m−2), who were expected to stay longer in ICU and hospital due to increased respiratory complications after cardiac surgery.

When compared with standard oxygen therapy care, prophylactic postoperative high‐flow nasal oxygen reduced hospital length of stay and intensive care unit re‐admission. The authors recommend routine use of high‐flow nasal oxygen after tracheal extubation in this cohort of patients and further testing of their hypothesis in large multi‐centre randomised trials.



Cardiac Output Based Fluids for Kidney Transplant

A small study on fluids for deceased donor kidney transplantation compared esophageal Doppler based stroke volume optimization with conventional clinical practice. Complications and delayed graft failure were no different and the primary endpoint – amount of fluid given – did not significantly differ. Pending larger studies this does not support cardiac output based fluid administration during kidney transplantation.




Albumin and Cardiac Surgery Mortality

An observational study of on-pump cardiac surgery links the use of 5% Albumin to lower in-hospital mortality and lower 30 day readmission when Albumin + crystalloid was used compared to only crystalloid. Composite morbidity and acute kidney injury did not differ. Randomized studies would be needed to confirm these findings but Albumin seems to hold more promise than the now discredited colloids like hydroxyethyl starch.



Neuraxial Technique and Arthroplasty Outcome

A retrospective study on total hip and knee arthroplasty complications and correlation with neuraxial technique yields some interesting results. Whereas Combined Spinal Epidural (CSE) was the commonest technique, numerous post operative outcomes – cardiac, pulmonary, gastrointestinal, renal/genitourinary, and thromboembolic complications, and prolonged length of stay – were all lower in the Spinal Anesthesia group, suggesting an advantage for this technique. Pure epidural technique outcomes were no different from CSE.



Inferior Vena Cava Filters and Mortality

Inferior vena cava filters are widely employed for thromboembolism where contraindications to anticoagulation exist. This study has the limitations of being retrospective and observational and as such is hypothesis generating, but its conclusions are important and concerning in suggesting a higher 30 day mortality with use of caval filters in those with contraindications to anticoagulation.



Cardiac Risk Prediction

A retrospective observational study compared well established cardiac risk prediction models: (i)the Revised Cardiac Risk Index, (ii)American College of Surgeons National Surgical Quality Improvement Program Surgical Risk Calculator, and (iii)the Myocardial Infarction or Cardiac Arrest calculator.

While agreement was better between the latter two (ACS NSQIP and MICA), there was 30% discordance between assigning high or low risk compared to the RCRI.

The NSQIP certainly seems more modern and comprehensive than the RCRI but the divergence in risk assessment certainly needs to be borne in mind.



SGLT2 Inhibitors and Peri-Op Ketoacidosis

SGLT2 Inhibitors are increasingly promoted for diabetes and this article again highlights the risks of euglycemic ketocacidosis. Fasting, hypovolemia, infection, surgery, bowel preparation, keto diets before bariatric procedures, excessive alcohol are some of the predisposing conditions. Treatment involve some aggressive rehydration and Potassium supplementation with Insulin infusion and sometimes bicarbonate. Prevention may necessitate withholding SGLT2 Inhibitors for up to three days, more than the recommended 24 hours.



ACEIs, ARBs and Post-Op Renal Injury

ACE Inhibitors and ARBs are commonly held before major non-cardiac surgery. This study showed that such practice did not prevent the development of post-op acute kidney injury. While the other rationale is to hold them to prevent severe or intractable hypotension, this may not be the mechanism causing acute kidney injury.



Assessment of functional capacity before major non-cardiac surgery

Functional capacity is frequently subjectively assessed but this prospective cohort study recommends against it in favour of more objective measures. They compared it with alternative markers of fitness (cardiopulmonary exercise testing [CPET], scores on the Duke Activity Status Index [DASI] questionnaire, and serum N-terminal pro-B-type natriuretic peptide [NT pro-BNP] concentrations) for predicting death or complication. Only DASI scores were associated with predicting the primary outcome of death or myocardial infarction within 30 days.