Article Notes
- Post-operative complications occur in 25-40% of patients, making this the most important focus for improving perioperative outcomes.
- Failure to rescue is a common problem, and few postoperative patients actually experience sudden deterioration, instead hindsight shows a slow and steady decline leading to the critical event that generates an emergency response.
- Remote monitoring uses medical-grade biosensors wirelessly linked to a central receiver, integrated with an electronic patient record, allowing patients free movement.
- The handful of currently available systems monitor combinations of heart rate ± variability, ECG, respiratory rate, pulse oximetry, blood pressure, temperature, posture and activity.
- Continuous monitoring may then be integrated with systems that calculate an Early Warning Score, automatically notify staff of early deterioration, or in more advanced future systems, allow prediction of deterioration.
- Although feasible, all current systems suffer from practical and technical issues that can limit their sensitivity and specificity.
- Evidence of benefit is still very patchy, although data suggests that automated notification of deterioration leads to earlier responses by treating teams, with small interventions, reducing the burden on rapid response / MET systems.
- No actual morbidity or mortality outcome data is yet available.
- They note that there is no gold standard to measure frailty, although there are many attempts to reliably identify and measure frailty across its many domains.
Nonetheless frailty is strongly associated with perioperative morbidity and mortality.
One proposed indicator of physical frailty is the presence of three of Fried's five factors: unintentional weight loss; grip strength weakness; exhaustion; slow walking speed; and low physical activity.
Frailty is "...a multidimensional state of reduced physiological reserve, resulting in increased vulnerability to stressors, decreased resilience, and loss of adaptive capacity."
Prehabilitation aims to increase physiological reserve through pre-operative intervention, including but not limited to exercise, nutrition and inspiratory muscle training.
What did they do?
Using a randmoized, double-blind crossover study, Fong et al anaesthetized eight male volunteers twice with 1.2% isoflurane for 1 hour, after propofol induction. In the final 10 minutes subjects were randomized to IV caffeine or placebo. No opioids were administered.
Receiving IV caffeine hastened emergence by over 40%, as measured by BIS and psychomotor testing.
Return of gag reflex was used as the marker of emergence, although time to emergence was consistent with eye opening and BIS.
How much caffeine did they give?!?
15 mg/kg of caffeine citrate, equivalent to 7.5 mg/kg of base caffeine – the same caffeine as in two large cups of coffee for a 70 kg male.
Come on, surely this isn't that important?
Although the mean 7 min difference may not appear clinically significant, especially when using more modern volatiles, this study is a good proof of concept of how caffeine may be a useful clinical tool when faced with delayed emergence after anesthesia and for patients at greatest risk of persistent psychomotor depression post-anesthesia, such as the elderly.
Daniel Jolley
Boer, Touw and Loer describe the concept of continuous, remote vital sign monitoring and the current level of evidence for it's proposed benefit.
We know that...
Continuous remote vital sign monitoring on surgical wards may improve early recognition of deterioration.
So, any real evidence?
Be cautious...
While the hope is that remote monitoring can improve patient safety, it could disingenuously be used to justify reduced ward staffing and hospital stay length by normalizing the risk of our current postoperative harm status quo.
Daniel Jolley
A useful review of the role of rehabilitation in frail patients by Milder, Pillinger and Kam.
Final word: although attractive, prehab has not yet been shown to improve outcomes in frail patients, though this is likely due to the absence of high quality studies.
Daniel Jolley