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Welsh Anaesthetic Trainees Journal Club

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August 2017

Journal Club 1st August

Effectiveness of apnoeic oxygenation during intubation: systematic review and meta-analysis.

Annals of Emergency Medicine;2017:x:1-12

Presented by: Dr M. Gallagher

Background

  • Concept-> administration oxygen during apnoeic period of intubation.
  • Rationale->  ability of alveoli to capture oxygen via passive process without ventilation.
  • Importance-> higher risk hypoxaemia during the intubation of the critically ill patient in ICU or ED setting.

Design & Setting

  • Systematic review and meta-analysis
  • Study overall effect of apnoeic oxygenation during emergency intubation on

1) hypoxaemia

2) ‘first pass’ success intubation

3)  lowest oxygen saturation

Inclusion criteria

  • Oxygenation during apnoeic period via

– nasal cannula (NO DESATURATION)

– high flow oxygen nasal cannula (THRIVE)

– nasopharyngeal catheter or modified laryngoscope.

  • Intubations performed in ICU or ED settings.
  • RCT’s and observational studies in the last 10 years.

Exclusion criteria

  • Intubations in ‘out-of hospital’ settings or in theatres.

Outcomes

  • Lowest SpO2 peri-intubation
  • ‘First pass’ success
  • Incidence hypoxaemia
    1. SpO2 <93%
    2. SpO2 < 80%
    3. SpO2 <70%
  • Duration of mechanical ventilation
  • ICU length of stay and mortality

Results

  • Included 8 emergency department or intensive care based studies
  • Total 1837 patients
    • Apnoeic oxygenation 982 patients
    • No apnoeic oxygenation 855 patients
  • High flow oxygen nasal cannula (NO DESAT) most studies.
  • Standard nasal cannula in ED.

For apnoeic oxygenation

  • Lowest peri-intubation SpO2 was higher than for standard oxygenation.
  • Associated with increased ‘first pass- success rates.
  • Decreased risk of incidence SpO2 < 93%.
  • Not associated with SpO2 < 805 or <70%.
  • No association with duration of mechanical ventilation.
  • Decreased length of stay on ICU.
  • No association with ICU mortality.

Subgroup analysis

  • Overall no difference between study design or  risk of bias.
  • Apnoeic oxygenation favoured trainees ‘subgroup when proceduralist expertise was evaluated.
  • Results were not statistically significant

Conclusions

  • No adverse effects for very simple procedure -> ?beneficial in emergency scenarios particularly when a trainee is intubating.
  • Different techniques used
    • Emergency Department = standard nasal cannula
    • Intensive Care Unit = high flow nasal cannula.
  • No clear overall consensus in the literature.

Strengths

  • Meta-analysis-> good use of statistical analysis to try overcome any bias.
  • Relevant to patient groups in question

Weaknesses

  • Quality of included studies (low-moderate).
  • Clinical heterogenitcity ( clinical setting, context for intubation, methods of pre-oxygenation and apnoeic oxygenation).
  • Not able to assess publication bias.

Implications

  • Potentially a useful adjunct in emergency intubation

Potential for impact

  • Seems to be of benefit
  • Relatively simple and safe intervention with few complications
  • Evidence surrounding apnoeic oxygenation still not certain and some concerns raised about quality of available studies

Journal Club 27th June 2017

Efficacy and safety of intravenous lidocaine for postoperative analgesia and recovery after surgery: a systematic review with sequential trial analysis. British Journal of Anaesthesia 2016;116(6):770-783 doi:10.1093/bja/aew101

Presented by: Dr H. Pudge

Background

  • Improvement of postoperative pain and other perioperative outcomes remain a significant challenge and a matter of debate among perioperative clinicians.
  • This systematic review aims to evaluate the effects of perioperative i.v. lidocaine infusion on postoperative pain and recovery in patients undergoing various surgical procedures.

Design & Setting

  • Relevant RCTs up until May 2014 searched for in databases.
  • 45 studies and 2 co-publications included in quantitive analysis
  • 42 studies contribute to quantitive analysis

Subjects

  • 45 RCTs published between 1985 & 2014
  • Containing 2802 participants

–1395 received iv lidocaine

–1407 control (saline/no treatment)

  • No overall cohort data

Intervention

  • Meta-analysis including trial sequential analysis

Outcomes

  • Primary Outcomes

–Pain score

–Postoperative ileus

–Functional gastrointestinal recovery

  • Secondary Outcomes

–Length of hospital stay

–Surgical complication

–Adverse events

–Postoperative nausea and vomiting

–Intra- and postoperative opioid requirements

–Functional postoperative neuropsychological scale

–Patient satisfaction

–Cessation of the intervention

Results

  • Iv lidocaine

–Reduced early (md -0.84) and intermediate (-.34) postoperative pain -> laparoscopic/open abdominal surgery.

–Reduced time to first flatus passed (md -5.49 hr), but did not significantly reduce time to first defacaetion

–Reduced hospital stay (md -0.31 days)

–Reduced intraoperative opioid requirements ( md -3.3 meq mg)

Conclusions

  • There is limited evidence suggesting that i.v. lidocaine may be a useful adjuvant during general anaesthesia because of its beneficial impact on several outcomes after surgery

Strengths

  • More trial data for lidocaine v placebo
  • Lots of studies included

Weaknesses

  • Poor evidence strength of iv lidocaine v thoracic epidural anaesthesia
  • No standard lidocaine infusion or bolus– variation across trials included in meta-analysis
  • Small trials included
  • Poor quality evidence for secondary outcomes, not all outcomes analysed

Implications

  • Some evidence that iv lidocaine reduces postoperative pain and early PONV for laparotomy/laparoscopy

Potential for Impact

  • Consider use in abdominal surgery
  • More information/research required on specific types of surgery and in comparison with thoracic epidural anaesthesia

July 2017

Written by: Dr C. Williams

A national survey of the effects of fatigue on trainees in anaesthesia in the UK.  McClelland L, Holland J, Lomas J-P, Redfern N, Plunkett E. Anaesthesia 2017 doi:10.1111/anae.13965

This article publishes the results of a survey carried out by two Welsh trainees looking at the impact of fatigue reported by anaesthetic trainees. With news headlines of junior doctors dying following crashes while driving after night shifts and recent BBC Inside Out South coverage of a junior doctor’s driving ability after a night shift* this is an important topic to look at. Since the introduction of the European Working Time Directive in 2009 the working patterns of junior doctors have changed with far more shift work and often rotas that change from days to nights and back again very quickly. Also with training arranged in the way it is now, many trainees may move hospital every 6 months to 1 year, sometimes over large geographical areas.  Maybe this issue has always been the case, maybe we are more aware due to increased knowledge, understanding and recognition of the effects of fatigue but what is clear is that it is not something that can be ignored. The results of this survey highlight some worrying figures. High numbers of trainees say that fatigue has affected their physical health, psychological wellbeing, personal relationships and ability to train including exams, audits/QI projects. A high proportion reported being involved in an accident or near miss when travelling home after a night shift. This has implications both to the safety of the trainee and to the public.

This survey has highlighted this important issue. It has been a contributing factor in the establishment of a ‘fatigue group’ in association with the AAGBI, GAT and the RCoA. There have been efforts made by some trusts to highlight the risks of fatigue and provide strategies and advice to help junior doctors. Of course, fatigue is not something that only affects doctors or even just healthcare professionals but anyone who works shifts particularly night shifts. Although this survey only concentrates on one set of junior doctors, it would seem sensible that strategies that work for trainee anaesthetists to cope with fatigue may be generalizable to other groups of people affects by this issue. Hopefully highlighting the problem of fatigue and supporting doctors, managers and trusts on how to tackle this issue will make things safer for doctors, and ultimately our patients and the public.

*http://www.bbc.com/news/av/uk-england-berkshire-38716140/doctors-fall-asleep-driving-after-punishing-night-shifts-the-bbc-learns

Prehabilitation in perioperative care. Moorthy K, Wynter-Blyth V. British Journal of Surgery 2017;104(7):802-803. doi:10.1002/bjs.10516

This is article looking at prehabilitation and the role it plays in patients with upper gastrointestinal cancer. It is a well known fact now that there are greater demands placed on surgical systems with the patient population undergoing major abdominal surgery becoming older and increasingly frail with multiple co-morbidities. This is coupled with organizational issues such as a drive for earlier postoperative discharge and with surgeons facing increased scrutiny of their work and complication rates in response to governmental and public demands for greater transparency. High-risk patients are undoubtedly at greater risk of adverse postoperative events and a longer recovery time. The article talks about enhanced recovery programmes which are well established in many surgical specialties and have led to post operative outcome improvements. However, they mainly focus on the intraoperative and postoperative phases of the patient journey. The concept of prehabilitation is based on the principle that amongst other things, structured exercise in the preoperative period will provide the patient with a ‘physiological buffer’ to withstand the stress of surgery. Although preoperative exercise is associated with improved preoperative functional capacity there is currently limited evidence to show that it improves postoperative outcomes. There are several clinical trials in progress that aim to address this evidence gap. Importantly, prehabilitation must be about more than just exercise. Addressing all the other factors that contribute to outcome such as body weight, nutrition, alcohol, smoking and the critical but often forgotten psychological aspect. The preoperative period is an ideal opportunity to make the most of a ‘teachable moment’ and emphasise the importance of making positive lifestyle changes. This is an exciting area that is being explored. The publication of new clinical trials should provide some answers. Future research is needed possibly looking at cost-effectiveness and how prehabilitation can be linked to enhanced recovery pathways. Ultimately the aim is a better outcome for the patient.

Claims for compensation after injuries relating to airway management: a nationwide study covering 15 years. Fornebo I, Simonsen KA, Bukholm IRK, Kongsgaard UE. Acta Anaesthesiologic Scandinavica 2017 doi:10.1111/aas.12914

One of the anaesthetist’s ‘raison d’être’ is to manage the airway by whichever method they chose for the given situation – facemask, oral or nasal airway, a supraglottic device or an endotracheal tube. However, no method is risk free and all may cause complications ranging dental damage, soft tissue trauma through to catastrophic complications due to failure to secure the airway. A subset of patients have specific characteristics that may mean we can predict a likely difficult airway. Equally there are patients who have none of these characteristics yet are found to have a difficult airway at induction of anaesthesia.

Although not common, disastrous outcomes with failed or difficult tracheal intubation are well known to anaesthetists. An integral part of our training is the learning strategies to manage both the anticipated and unanticipated difficult airway.

This study looked at compensation claims relating to airway management over a 15-year period in Norway. 0.8% of claims relating to anaesthesia involved airway management. 38% of claims related to dental injuries. Severe injuries were defined as failed intubation, misplaced endotracheal tube, aspiration or a ‘miscellaneous’ group. They accounted for 10% of all the claims but made up 37% of claims relating to emergency procedures. Interestingly all claims made from patients needing airway management in a pre-hospital setting and 87% of the claims from ICU were rejected. This may reflect the situation in which airway management is considered a life-saving procedure.

Although the results of this study are specific to Norway it serves to highlight that airway management can result in complications and we should continue to be vigilant particularly in emergency cases.

Intraoperative ketamine for prevention of postoperative delirium or pain after major surgery in older adults: an international, multicenter, double-blind, randomized clinical trial. Avidan MS, Maybrier HR, Abdallah AB, Jacobsohn E et al. The Lancet. 2017;390(10091):267-275 doi:10.1016/S0140-6736(17)31467-8

In patients over the age of 60 delirium is one of the most common complications and is associated with increased morbidity and mortality. It has many causes and the pathophysiology is not completely understood which makes it difficult to predict and treat. In surgical patients risk factors are likely to be pain, treatment with opioids and the inflammatory response to injury. In theory a drug that provides analgesia and prevents delirium would be an important advance in perioperative medicine. A postoperative infusion of dexmedetomidine has shown promise although further studies are recommended. However, this drug is expensive and requires a continuous intravenous infusion therefore is unlikely to be a practical solution.

It has been reported that intraoperative subanaesthetic ketamine administration reduces postoperative pain, reduces postoperative opioid requirement and reduces the postoperative markers of inflammation. Based on this the study authors hypothesise that intraoperative ketamine may reduce the incidence of postoperative delirium. But ketamine is also well known to be a psychoactive drug with hallucinogenic properties so could theoretically contribute to postoperative delirium.

This multicentre study randomly allocated patients to one of three groups – placebo (to receive normal saline), low dose ketamine (0.5mg/kg) or high dose ketamine (1mg/kg) to be given after induction of general anaesthesia but before surgical incision. They found that there was no difference in the incidence of delirium in any of the groups and there were more postoperative hallucinations and nightmares with increasing doses of ketamine.

In conclusion, ketamine does not reduce postoperative delirium and may actually increase harm by increasing the incidence of hallucinations and nightmares. Ketamine use has increased particularly with the introduction of enhanced recovery programmes – maybe the time has come for some further studies regarding its use in elderly patients.

Falls from the O.R. or procedure table. Prielipp RC, Weinkauf JL, Esser TM, Thomas BJ, Warner MA. Anesthesia & Analgesia 2017. doi:10.1213/ANE.0000000000002125 

Patients falling from the operating table is a scenario that thankfully most anaesthetists will not encounter. I know of one event that happened in a neighbouring theatre when I had just started my anaesthetic training. The patient was unharmed and that was the last I heard about it. The American Society of Anesthesiologists highlights that anaesthesia is the practice of medicine with one of its primary foci being ‘management and preservation of patient safety’. A patient falling from the operating table is a clear breakdown of this responsibility and can have medical, professional, legal and financial consequences.

This study looked at claims recorded in the Anaesthesia Closed Claims Project database looking for claims associated with falling from the year 2000 to now. There were 21 claims identified – 15 in patient having general anaesthsia and 4 in those receiving regional anaesthesia. Approximately half of the claims resulted in payouts to the patients ranging from $18,000 to $925,000. Patient falls from the operating table must be considered preventable adverse events. Injuries from falls such as these can be catastrophic including brain damage, paralysis and even death.

This paper talks very much about the anaesthetists duty and role in preventing falls. The reality is that it should preventing falls should be shared responsibility for every member of the team. Many of the falls occurred when patients were partially sedated or awakening from general anaesthesia and potentially confused or agitated. From experience this is the time at which other staff may be distracted and concentrating on other tasks. The entire operating theatre team need to be proactive in maintaining patient safety at all times.

 

Perioperative COX-2 inhibitors may increase the risk of post-operative acute kidney injury. Abrahamsson A, Oras J, Snygg J, Block L. Acta Anaesthesiologica Scandinavica 2017;61(7):714-721 doi:10.1111/aas.12912

This was a study looking at patients who had undergone pancreaticoduodenectomy. In 2012, enhanced recovery after surgery (ERAS) guidelines were published for these patients recommending a restrictive fluid regimen to avoid the fluid overload that has been shown to be hazardous for these patients. Acute kidney injury (AKI) is not uncommon after major abdominal surgery and is known to be a major cause of postoperative morbidity and mortality. Perioperative hypotension and hypovolaemia are known to contribute to AKI.

Anaesthetists in Gothenburg, Sweden made the observation that patients undergoing open pancreatic surgery with an ERAS restrictive fluid protocol were more likely to develop postoperative AKI and spend longer on ICU. Consequently, they reviewed the notes of patients who underwent pancreatic surgery prior to the introduction of the ERAS fluid protocol and compared this to patients who underwent surgery after the introduction of the ERAS fluid protocol. They found that the incidence of AKI was significantly higher in the patients who underwent surgery using the ERAS restrictive fluid protocol (13% vs 2% in the pre-ERAS patient group). They also found that COX-2 inhibitors were given more frequently to patients in the ERAS group.

They concluded that the combination of a goal-directed restrictive fluid therapy with the administration of COX-2 inhibitors significantly increases the risk of AKI.

Postoperative respiratory complications in patients at risk for obstructive sleep apnea: a single-institution cohort study. Ramachandran SK, Pandit J, Devine S, Thompson A, Shanks A. Anesthesia & Analgesia 2017;125(1):272-279 doi:10.1213/ANE.0000000000002132 

Obstructive sleep apnoea (OSA) is not an uncommon condition and is thought to affect up to 25% of middle-aged men and up to 10% of middle-aged women. It has a significant impact on quality of life, life expectancy, cardiovascular disease and respiratory disease. Recent evidence also suggest that it is associated with a 3 to 6 times increase in post-operative respiratory complications. The majority of patients with OSA remain undiagnosed and preoperative screening remains the most efficient method to identify those at risk.

This retrospective observational study looked back over the notes of 108,479 patients and assigned OSA risk retrospectively using the Perioperative Sleep Apnea Predictive (PSAP) score*. They found that a high PSAP score was associated with a higher incidence of postoperative respiratory complications and an increased need for postoperative intubation. Other factors that were associated with postoperative respiratory complications include the anaesthetic agent used, neuromuscular blocking agents and opioid use.

Patients with suspected OSA should be identified, assessed and commenced on appropriate treatment preoperatively where possible. They may also require a modification of the anaesthetic technique used to try to minimize the risk of postoperative respiratory complications (PRCs) and a recognition that they are at higher risk of developing PRCs.

*Ramachandran SK, Kheterpal S, Consens F et al. Derivation and validation of a simple perioperative sleep apnea prediction score. Anesth Analg. 2010;110:1007-1015

Body height and the spread of spinal anaesthesia for caesarean section: a prospective controlled trial. Acta Anaesthesiologica Scandinavica 2017;61(7):824-831 doi:10.1111/aas.12928

Spinal anaesthesia is the preferred anaesthetic technique for caesarean sections. However, as this article rightly points out there is a considerable variability in the dose regimens used. As a trainee one only has to ask several different consultants to realise that each one has a preferred dose for the ‘best’ spinal anaesthetic! The aim is a dose of intrathecal bupivacaine that maintains anaesthesia but minimizes the risk of maternal hypotension. Several patient variables are usually factored into predicting the spread of spinal anaesthesia including age, height, weight and body mass index. The time required to achieve an adequate sensory block for surgery tends to increase linearly with height and decrease with increasing weight.

This study hypothesized that shorter patients need a lower spinal anaesthesia dose than taller patients. 270 pregnant women were assigned to either the tall (T) group or shorter (S) group. Both groups were then randomly assigned to one of nine subgroups of intrathecal ropivacaine dose (between 7-15mg). They found that height did not significantly affect the height of the block achieved with the different doses. However, larger ropivacaine doses were associated with increased hypotension which was more pronounced in shorter patients.

This was a small study and maybe separating patients on height alone is too simplistic to answer the question. Ultimately, the answer as to the best dose of local anaesthetic for spinal anaesthesia remains to be discovered.

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