ANESTHESIOLOGY – July 2016 TOC

On the Cover:
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Image source: Anesthesiology

Blood transfusions are associated with morbidity and mortality. However, restrictive thresholds could harm patients less able to tolerate anemia. In this issue of Anesthesiology, Hovaguimian and Myles present the results of a systematic review to quantify the effects of transfusion strategies, concluding that restrictive transfusion strategies should be applied with caution in high-risk patients undergoing major surgery.

  • Hovaguimian and Myles: Restrictive versus Liberal Transfusion Strategy in the Perioperative and Acute Care Setting: A Context-specific Systematic Review and Meta-analysis of Randomized Controlled Trials, p. 46

  • Beattie and Wijeysundera: Approaching a Safe Last Resort: Triggers for Perioperative Blood Transfusion, p. 11

Read the full article here

 

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A Novel Mobile Phone Application for Pulse Pressure Variation Monitoring Based on Feature Extraction Technology

Olivier, D. et al. Anesthesia & Analgesia. July 2016. 123(1). pp. 105–113

https://creativecommons.org/licenses/by/2.0/

Image source: Graeme Paterson // CC BY 2.0

Background: Pulse pressure variation (PPV) can be used to assess fluid status in the operating room. This measurement, however, is time consuming when done manually and unreliable through visual assessment. Moreover, its continuous monitoring requires the use of expensive devices. Capstesia™ is a novel Android™/iOS™ application, which calculates PPV from a digital picture of the arterial pressure waveform obtained from any monitor. The application identifies the peaks and troughs of the arterial curve, determines maximum and minimum pulse pressures, and computes PPV. In this study, we compared the accuracy of PPV generated with the smartphone application Capstesia (PPVapp) against the reference method that is the manual determination of PPV (PPVman).

Methods: The Capstesia application was loaded onto a Samsung Galaxy S4TM phone. A physiologic simulator including PPV was used to display arterial waveforms on a computer screen. Data were obtained with different sweep speeds (6 and 12 mm/s) and randomly generated PPV values (from 2% to 24%), pulse pressure (30, 45, and 60 mm Hg), heart rates (60–80 bpm), and respiratory rates (10–15 breaths/min) on the simulator. Each metric was recorded 5 times at an arterial height scale X1 (PPV5appX1) and 5 times at an arterial height scale X3 (PPV5appX3). Reproducibility of PPVapp and PPVman was determined from the 5 pictures of the same hemodynamic profile. The effect of sweep speed, arterial waveform scale (X1 or X3), and number of images captured was assessed by a Bland-Altman analysis. The measurement error (ME) was calculated for each pair of data. A receiver operating characteristic curve analysis determined the ability of PPVapp to discriminate a PPVman > 13%.

Results: Four hundred eight pairs of PPVapp and PPVman were analyzed. The reproducibility of PPVapp and PPVman was 10% (interquartile range, 7%–14%) and 6% (interquartile range, 3%–10%), respectively, allowing a threshold ME of 12%. The overall mean bias for PPVappX1 was 1.1% within limits of −1.4% (95% confidence interval [CI], −1.7 to −1.1) to +3.5% (95% CI, +3.2 to +3.8). Averaging 5 values of PPVappX1 with a sweep speed of 12 mm/s resulted in the smallest bias (+0.6%) and the best limits of agreement (±1.3%). ME of PPVapp was <12% whenever 3, 4, or 5 pictures were taken to average PPVapp. The best predictive value for PPVapp to detect a PPVman > 13% was obtained for PPVappX1 by averaging 5 pictures showing a PPVapp threshold of 13.5% (95% CI, 12.9–15.2) and a receiver operating characteristic curve area of 0.989 (95% CI, 0.963–0.998) with a sensitivity of 97% and a specificity of 94%.

Conclusions: Our findings show that the Capstesia PPV calculation is a dependable substitute for standard manual PPV determination in a highly controlled environment (simulator study). Further studies are warranted to validate this mobile feature extraction technology to predict fluid responsiveness in real conditions.

Read the abstract here

Factors Influencing Parental Participation in Neonatal Pain Alleviation

Palomaa, A-K. et al. Journal of Pediatric Nursing. Published online: 20 June 2016

Highlights:

  • Parents have individual counseling needs and preferences.
  • More attention should be focused on providing sufficient counseling for parents.
  • Parents should be given space to assume the role of parents.
  • Family-friendly environment supports parents’ participation in pain relief.

Purpose:
Neonates are likely to experience numerous painful procedures in neonatal intensive care units (NICUs). Parents have expressed a wish to be more involved in their infants’ pain alleviation. The purpose of this study was to describe parents’ perceptions concerning the factors that influence parental participation in pain alleviation in an NICU.

Design and methods: The qualitative study was conducted in level II and III NICUs (7 units) of Finland’s four university hospitals. Data were collected through open-ended questionnaires and analyzed using inductive content analysis.

Results: Factors that promoted parental participation consisted of five main categories: parental counseling by staff, parents’ awareness of their own role, parents’ motivation to participate in pain relief, family-friendly facilities and good communication. Factors hindering parental participation consisted of eight categories, including restrictive environment, lack of knowledge, everyday life requirements, underestimation of parents, the nature of the medical procedures, procedure- and pain-related emotions, deteriorated health status of the child and mother and (8) uncertainty of parenting.

Conclusions: This study revealed a number of factors that are important to take into account when improving parental involvement in neonatal pain alleviation. Especially, parental participation can be promoted by providing sufficient counseling based on the parents’ needs and creating facilities that support parents’ participation.

Practice implication: Parents should be engaged as partners in caregiving and decision making, and they should be given space to assume the role of parents during their child’s hospitalization.

Read the abstract here

Prediction in airway management: what is worthwhile, what is a waste of time and what about the future?

Teoh, W.H. & Kristensen, M.S. British Journal of Anaesthesia (2016) 117 (1): 1-3.

Nørskov and colleagues1 randomized Danish anaesthesia departments in two groups, in order to investigate the effect of a structured airway examination on the ability to predict difficult intubation by direct laryngoscopy. The departments either continued with the pre-anaesthetic airway evaluation that they were used to, or applied the structured evaluation that consisted of five parameters (mouth opening, thyromental distance, Mallampati classification, neck movement and ability to prognath) and two questions (weight, previous difficult intubation) that culminated in the calculation of the Simplified Airway Risk Index (SARI).2This study found that clinicians were able to predict between nine and 50% of the patients where intubation with direct laryngoscopy was or would have been difficult. This success-rate in prediction difficulty was NOT different between the departments that continued with business-as-usual, and the departments where the evaluation of the seven predictive parameters was implemented.

Read the abstract here

Read the cited Nørskov et al. article abstract here

Non-neuraxial analgesia in labour

Robinson, C. & Howie, L.A. Anaesthesia & Intensive Care Medicine. Published online: 13 June 2016

Pain in labour is often described as one of the most severe pains experienced. Neuraxial techniques provide the most effective form of labour analgesia. However, not all women wish to have this or indeed want complete pain relief in labour. There are also subgroups of women in whom neuraxial techniques are contraindicated or attempted placement is unsuccessful. Therefore delivery units must be able to offer a range of non-neuraxial analgesia options for labour.

Read the abstract here

Patients ‘at risk’ as the anaesthetists shortage is predicted to increase

Campbell, D. The Observer. Published online: 11th June 2016

11415-2The NHS faces a critical shortage of anaesthetists that could force operations to be delayed and even threaten patient safety, doctors’ leaders have warned.

New research shows that by 2033 every hospital trust will have 10-20 fewer consultant anaesthetists than they will need to meet rising patient demand. It estimates that, while the NHS has agreed that its total of anaesthetists should expand to 11,800 by that date, on current trends it is likely to reach only 8,000 – a shortfall of 3,800, or about 33%.

The Royal College of Anaesthetists (RCoA), which carried out the research, warned that patients and the smooth running of hospitals would be hit if the existing shortfall in numbers was allowed to increase. Dr Liam Brennan, the college’s president, said: “Anaesthetists possess a unique and non-transferable skill set that is essential to maintaining core hospital services, so the potential impact of a reduced anaesthetic workforce would have serious implications for patient safety across the whole NHS. We already have fewer than we need and the shortages are worrying.”

The college’s latest census of the UK’s anaesthesia workforce, the first since 2010, also found that 74% of hospitals already rely on locum anaesthetists hired from medical employment agencies to ensure their rotas are full. The cost of that is part of the NHS’s huge annual bill – £3.7bn a year in England alone – for temporary staff.

Read the full news story here