Article Notes
The more I think about these results, the more interesting it is.
Reducing instrumental delivery rate is a real benefit for women, though is this due to avoiding epidurals or some other difference? How do we balance the issues of safety, analgesia, perineal trauma and maternal satisfaction? And how do we communicate this to labouring women in a meaningful way?
Questions questions...
Daniel Jolley
What did they do?
Wilson et al randomized 401 laboring women across multiple centers to either remifentanil PCA or pethidine/meperidine IM, then compared the progression of these women to labour epidural.
On the surface... this might appear disingenuous, as it compares remifentanil PCA to widely-shown-to-be-ineffective parenteral pethidine – rather than to the gold standard labour epidural. But it's also a study of how the technique might practically be used in the real world.
What they found
Women with remifentanil PCA progressed half as often to require epidural analgesia than those receiving pethidine (19% vs 41%).
Though it's one of the secondary findings that is most interesting: the remifentanil group were less likely to need instrumental delivery (15% vs 26%).
But don't get carried away
Despite the demonstrated superiority of remi PCA to pethidine, the technique is not without it's issues:
- Safety concerns regarding respiratory depression cannot be ignored, and because managing this relies upon staff vigilance, increased PCA use may conversely lead to a normalisation of risk and institutional complacency, rather than safety improvement.
- Analgesia is still inferior to epidural, even if maternal satisfaction is comparable.
- Technique acceptability might not be as good in communities with high pre-existing epidural use.
And finally... why are we so eager to do away with the labour epidural? Serious complications are very uncommon to rare, the technique is widely acceptable to women, and it is more effective than any other modality.
Is this change driven by the needs of pregnant women, or the health system's limited resources?
Daniel Jolley
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...
- 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.
Continuous remote vital sign monitoring on surgical wards may improve early recognition of deterioration.
- 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.
So, any real evidence?
- 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.
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