Anaesthesia
-
Observational Study
Clinician perception of long-term survival at the point of critical care discharge: a prospective cohort study.
Critical care survivors suffer persistent morbidity and increased risk of mortality as compared with the general population. Nevertheless, there are no standardised tools to identify at-risk patients. Our aim was to establish whether the Sabadell score, a simple tool applied by the treating clinician upon critical care discharge, was independently associated with 5-year mortality through a prospective observational cohort study of adults admitted to a general critical care unit. ⋯ Sabadell 2 patients had 71.0%, 52.7%, 44.8% and 23.7% 5-year mortality for these same age categories. The Sabadell score was independently associated with 5-year survival after critical care discharge. These findings can be used to guide provision of increased support for patients after critical care discharge and/or informed discussions with patients and relatives about dying to ascertain their future wishes.
-
Why do we need another PPE review?
This review contextualises the PPE issues with their (relatively low quality) evidence base, focusing particularly on anaesthesia given that this is a high-risk occupational group. Coming from both a UK expert and journal, the recommendations should be carefully considered in terms of the UK's severe COVID outbreak and PPE supply issues.
Important takeaways?
- The significance of airborne transmission, in particular the infectivity of airborne viral particles beyond 1 meter, is uncertain.
- PPE should be seen as an important and essential part of a larger safety system.
- Intubation is a high-risk procedure for aerosol generation. A ventilated negative pressure room and airborne-precaution PPE is recommended. Ventilation (frequency of air-exchange) is likely more important than negative pressure.1 Chinese evidence suggests COVID transmission at intubation is low with appropriate PPE, although there is wide variability in extremes of PPE used along with post-exposure disinfection (eg. showering).
- High-flow nasal oxygen and supraglottic airway (eg. LMA) placement may also be aerosol generating.
- Most risk of transmission from sneezing and coughing is probably droplet and contact, rather than airborne, although the science behind these questions are complex and uncertain. Evidence attempting to answer these questions is often from non-clinical settings.
- Fluid-resistant surgical masks when worn by staff may reduce transmission by at least 80%. Superiority of respirator masks (eg. P2,P3,N95) is not yet reliably supported by evidence.
- Cook highlights two main PPE problems: 1. PPE supply; 2. Inappropriate use of PPE (using higher level than required).
- PPE should be simple to remove (doff) after use, to reduce contamination risk. Cook notes that Canada's SARS experience highlighted increased risk of self contamination with more complex PPE.
On specific levels of PPE
- Contact precautions (gloves & gown) are recommended when in vicinity of COVID positive patient but not within 2 meters.
- Droplet precautions (+ mask & eye protecting) are recommended within 2 meters of patients.
- Airborne precautions (+ FFP3 respirator mask) are only recommended for aerosol generating procedures (AGP). However classification of procedures as AGP or not is only loosely evidence based.
"Public Health England recommends airborne precautions are used in ‘hot spots’ where aerosol generating procedure are regularly performed, if any suspected COVID-19 patients are present – these include intensive care unit, operating theatre, emergency department resuscitation bays and labour wards where mothers are in stage 2 or 3 of labour"
(Interesting that two recent meta-analyses found no evidence of benefit of N95 masks vs surgical masks for healthcare workers: Bartoszko 2020 & Long 2020.)
Hang on...
The elephant in the room is that the lack of PPE supply appears to be the main driver of the rapidly-changing PPE recommendations.
PPE choices need to be made in consideration of the spectrum of risk, hazard and cost, acknowledging different risk profiles depending on location, procedure and individual clinicians.
summary
-
It's worth highlighting that negative pressure confers no protection on those in the room, it's purpose is to prevent escape of contagion to areas outside the room. ↩
-
Letter Practice Guideline
Safety guideline: neurological monitoring associated with obstetric neuraxial block 2020: A joint guideline by the Association of Anaesthetists and the Obstetric Anaesthetists' Association.
Serious neurological lesions such as vertebral canal haematoma are rare after obstetric regional analgesia/anaesthesia, but early detection may be crucial to avoid permanent damage. This may be hampered by the variable and sometimes prolonged recovery following 'normal' neuraxial block, such that an underlying lesion may easily be missed. These guidelines make recommendations for the monitoring of recovery from obstetric neuraxial block, and escalation should recovery be delayed or new symptoms develop, with the aim of preventing serious neurological morbidity.