Minutes of the Liverpool Society of Anaesthetists Joint Meeting with the Section of Anaesthesia of the Manchester Medical Society
Thursday 20th March 2014

The Occasional Specialist - Outside your Comfort Zone’

Park Royal Hotel, Stretton, Warrington, WA4 4NS.

The meeting was opened by LSA President, Dr Janice Fazackerley, who welcomed delegates to the meeting. She explained the concept of the meeting to explore areas of occasional practice visited often out of hours when there is no possibility of patient transfer.

‘The Occasional Cardio-Thoracic Specialist’ 
Dr Ken Palmer, Liverpool Heart and Chest Hospital

Dr Palmer opened his talk by looking at the indication for one lung anaesthesia.   He said that this would allow surgical exposure, lung protection from blood, pus or air and improve ventilation in the presence of a broncho-pulmonary fistula or for independent lung ventilation. He quoted the figures from the NCEPOD oesophago-gastrectomy enquiry from 1998 which demonstrated that problems with double-lumen tubes and one lung ventilation featured in 30% of deaths reported.  Correct placement of these tubes is made easier with the use of fibre-optic bronchoscopy and the anaesthetist’s knowledge of bronchial anatomy.  Dr Palmer then gave a fibre-optic anatomical guide of the lungs.

Dr Palmer discussed the advantages and disadvantages of double lumen tubes compared to endo-bronchial blockers. Double lumen tubes have the advantages of better lung isolation, easier conversion from two to one lung ventilation, improved suction capability and the ability to put CPAP on the non-ventilated lung. In contrast, endo-bronchial blockers can be simpler to use in the presence of a tracheostomy or cuffed endotracheal tubes and are better for smaller airways such as in selective lobar block. However, they do not allow adequate suction and their positions frequently migrate. Double lumen tubes can occasionally cause trachea-bronchial injury and certainly during the initial intubation process, tearing of the cuff is common. He then demonstrated the difference between left and right sided double lumen tubes and the significant advantages of using a left sided tube. He thought that the only indication really for using a right sided tube was left pneumonectomy. He then considered the correct size, which was 39 for the average male, and 37 for the average female, with one size up or down for larger or smaller people.  For the average person of 170 cm in height, the tube should be 29 cms at the incisors, +/- 1 cm with every 10 cm change in height.

Dr Palmer then looked at the complications of double lumen tube insertion which is made far easier with the presence of a fibre-optic bronchoscope. He thought that bronchoscopy is vital for the correct placement of right sided double lumen tubes. He then went onto look at endo-bronchial blockers. He demonstrated why the use of fibre-optic bronchoscopy was absolutely vital for their correct placement. He quoted a paper (Bauer C, et al: Acta Anaesth Scand 2001;45:250) looking at the ease of placement, the failure rate and consequential surgical conditions, demonstrating the advantages of a double lumen tubes.

Dr Palmer then went onto the topic of pacemakers and stated the three indications for their placement; brady-arrythmias, cardiac resynchronisation therapy and the treatment of malignant tachy-arrythmias with intracardiac defibrillators. He looked at the NVG coding of pacemakers, pointing out the meanings of the 3 letters denoted on the pacemaker. These indicate the chamber paced, the chamber sensed and the response to sensing. So a DDD pacemaker means that both atrium and ventricles are paced, both are sensed and the response to sensing can be either triggered or inhibited. In contrast a VVI pacemaker would indicate a ventricle being paced, a ventricle sensed with an inhibited response. He then went into the problems of pacemakers and in particular, the issues around electro-magnetic interference which may come from diathermy, radiofrequency ablation and MRI among others. These can all lead to problems such as reprogramming, misinterpretation, inhibition of pacing, and even over-heating of pacemaker wires. He thought that the pre-assessment service should ensure that pacemaker details are known and ensure that a pacemaker has been checked within the last 12 months. He explored the issues of using clinical magnets which should only be used in an emergency.  Magnets will switch all modern pacemakers to an asynchronous fixed rate. For example, a DDD pacemaker would be put into DOO. However, he warned that this was not entirely without its problems and asynchronous pacing can cause further dysrhythmias. He went onto intra-cardiac defibrillators (ICDs) where the main problem with these devices occurred when emergency surgery had to be undertaken out of hours and the defibrillator could not be switched off by the ECG Department. The use of a clinical magnet in this situation will cause suspension of the anti-tachycardia therapies and with its removal, the pre-programmed mode will resume.

In the final section of the talk, Dr Palmer spoke about coronary artery stents.  He firstly described the difference between bare metal stents and the newer drug eluting stents which were coated with a polymer anti proliferative drug which inhibits endothelial regrowth. Both stents had very different anti-platelet recommendations with the latter requiring a minimum of 12 months of aspirin and clopidogrel therapy. Stopping anti-platelet therapy before it was recommended had a 30 times greater risk than normal of stent thrombosis. Indeed, if anti-platelet therapy is stopped within the first month of stent insertion, there is a greater than 25% incidence of stent thrombosis. Therefore prior to any surgery, there should be full discussion between cardiologist, surgeon and anaesthetist and at the very minimum, aspirin should always be continued.

Dr Palmer then quoted a paper by Oscarsson A, et al. (BJA 2010; 104 (3): 305-12) which demonstrated that continuing aspirin reduced the rate of major adverse cardiac events without increasing bleeding rates.   There was no time to take any questions.

 

‘Neurosurgical Emergencies
Dr Bill Bickerstaffe, The Walton Centre

Dr Bickerstaffe started his talk by speaking about his move from Southport and Ormskirk District General Hospital to the Walton Centre, the largest specialist Neurosurgical Unit in the UK. He talked about the large workload and the many urgent and emergency calls that the unit receives every day. He described the reputation that Walton has amongst some colleagues in the region, as being the ‘regional refusal centre’, with its inconsistent advice and the difficulty obtaining even that. However, he described Walton’s point of view, where some hospitals had referred patients too late or too often and then when these patients arrived, they had sometimes been transferred by junior medical staff to a low standard.

Dr Bickerstaffe described severe traumatic brain injury, which was defined as when a patient has a Glasgow Coma Score of less than nine after resuscitation.    There are 10 to 20,000 brain injuries of this severity annually in the UK and they have a high mortality (39%). Those who do survive who are often in young men, have a high degree of neurological deficit. Therefore, the initial management and transfer is very important in helping to improve outcome. He stressed the importance of avoiding hypoxia, hypotension, the presence of an intra-cerebral haematoma for more than four hours and hyperpyrexia. Rapid resuscitation, protection of the cervical spine and swift preparation for transfer are vital, providing that any other life-threatening injuries are treated first. He elaborated on the simple requirements; securing the airway with attention to the cervical spine, normal blood gases, MAP greater than 80 mmHg, helping to produce a cerebral perfusion pressure of greater than 60 mmHg. Other important factors to consider included the prevention of seizures, monitoring any changes in pupillary size, ensuring normoglycaemia and the maintenance of a Haemoglobin concentration greater than 80 g/L.

Dr Bickerstaffe then looked at the NICE (2007) guidelines for CT scanning, and the criteria for referral to a neurosurgical unit. The latter included all patients with a persistent GCS of less than 9 or with further deterioration and progressive focal signs after admission. Other indications included unexplained prolonged confusion, seizure without full recovery, and a CSF leak. He went through the newly produced Walton referral guidelines for radiology and A&E trauma units. This was designed to improve access for appropriate patients.

Dr Bickerstaffe described other neurological emergencies that may involve anaesthetists. This included subarachnoid haemorrhage, which was more common in the middle aged, and had a 50% mortality at one month. He briefly described the management. Whatever the cause, a good transfer was imperative. He highlighted the importance of cervical spine immobilisation, and the splinting of any other injuries, the presence of an oro-gastric tube and bladder catheter, and the insulation of the patient to prevent excessive cooling.  A skilled doctor and assistant who were familiar with the case with appropriate equipment and relevant documentation were also vital. He referenced the AAGBI   guidelines (2006) on the safe transfer of patients with brain injuries.   He briefly spoke about the management of seizuresand their  treatment with the initial use of Lorazepam or Diazepam and the importance of checking for hypoglycaemia as a cause. If seizures had not stopped within 5 minutes, Phenytoin 20 mgs/Kg over 20 minutes should then be administered, whilst ensuring that the airway remained patent and the patient was being adequately oxygenated.  

Dr Bickerstaffe completed his talk and there was no time for further questions.

‘Vascular Emergencies’  
Dr Simon Rogers, Royal Liverpool Hospital.

Dr Rogers opened his talk by describing the way that vascular services are being increasingly centralised with the bulk of patients now being transferred from spoke hospitals and how the surgical care of these patients was changing with the involvement of interventional radiology.  He thought that the inevitable added time of transfer before going theatre, may become increasingly important.  Consequently, there may be little time for any significant pre-operative investigation and therefore we, as anaesthetists, are often left just to get on with it.  He pointed out that the bulk of vascular patients were inevitably at high risk of cardiovascular complications.  He looked at Lee’s revised cardiac risk which took into consideration the type of surgical procedure, a history of ischaemic heart disease, congestive heart failure, cerebro-vascular disease, pre-existing diabetes and renal failure. He pointed out that the majority of vascular patients, particularly when presenting as an emergency scored 3 or more and therefore had a greater than 11% risk of a major cardiac event. In a study by Hertzer et al, from 1984, which looked at 1000 patients having vascular surgery from abdominal aortic aneurysm repair, to peripheral vascular procedures, only 8% had no coronary artery disease. A further paper two years later in 1986 demonstrated similar findings.

Dr Rogers looked at a study from Gothenburg in 1994 by Ardvidsson et al, which looked at 1,361 patients having major surgery, ranging from general, peripheral vascular to orthopaedics. It found that two thirds of vascular patients had complications, whereas this was the case in only a quarter of general and a third of orthopaedic patients.

Dr Rogers then looked at how to give better emergency anaesthesia. He highlighted the importance of early and appropriate antibiotics, scrupulous aseptic techniques, particularly for central line insertion and low tidal volume ventilation with PEEP.  He was unsure about the role of the oesophageal Doppler and goal directed therapy using this machine but he thought it was vital to avoid the lethal triad of hypothermia, coagulopathy, and lactic acidosis. He thought the most important thing was ensuring that all ingredients are used well rather than sticking to a standard recipe.

Dr Rogers looked at bleeding and the importance of checking clotting factors, as quickly as possible. He thought that the introduction of major haemorrhage protocols, following on from the work in major trauma, was important. He highlighted the progress made by near patient coagulation testing such as with Rotem, although better outcomes were not yet proven. He certainly thought that the cell saver was a very important piece of equipment to use.

Dr Rogers discussed briefly the POISE trial which looked at the effects of slow release Metoprolol in patients undergoing non cardiac surgery.   It demonstrated that although there were fewer myocardial infarctions, there were significantly more strokes and overall mortality was higher. He spoke about the paper by Lindenauer et al (JAMA 2004; 291 (17): 2092 – 2099) which demonstrated that the use of lipid lowering medications in the peri-operative period was associated with reduced mortality among patients undergoing major non cardiac surgery.    He then touched on the presence of coronary artery stents and the risk of peri-operative thrombosis due to cessation of anti-platelet drugs. 

Dr Rogers discussed ruptured abdominal aortic aneurysm. He produced some figures about the 5 year risk of rupture. When the diameter is 5 to 5.9 cm, there was a 25% risk, 6 – 6.9, 35% risk, and a greater than 7 cm diameter, there is a 75% risk. However in patients who have abdominal aortic aneurysms present, death from rupture only occurs in 15%, the rest of the population die from other causes. He demonstrated the high mortality from emergency, compared to elective AAA repair (36 versus 6.2%). He then quoted a paper from the British Journal of Surgery in 2005 by Hadjianastassiou which looked at 1,896 patients, of which 1,289 had elective repair and 605 were treated as emergencies.  There was a hospital mortality of 9.6% for elective repair and this figure was 46.9 for emergency repair. He then showed the Hardman score from 1996 for assessment of these patients which looked at age, loss of consciousness, serum creatinine, haemoglobin and the presence of ischaemia on the ECG.   In 1996, a score of 2 or more was universally fatal, but this has not been validated in recent studies. Dr Rogers quoted the NCEPOD recommendations from 2005, which stressed the importance of close cooperation and team work between surgeon and anaesthetists at consultant level. It also stressed the importance of hospital volume, the presence of a vascular rota and demonstrated that transferred patients did no worse.

Dr Rogers then went through his personal management of such cases. He spoke about the importance of rapid infusion of warmed fluids and the use of a cell-saver. He thought that keeping patients warm was vital for a good outcome. He also thought that central venous access was not essential and the presence of large peripheral cannulae certainly was perfectly acceptable. The exact anaesthetic  technique was not of great importance but he thought the use of a large amount of Fentanyl was a good idea.  As in trauma management, the use of permissive hypotension until the clamp went on may be helpful but once bleeding from the aneurysm had been controlled, the aggressive use of blood, FFP and platelets was important. Post-operative extubation could occur when the patient was warm and stable and when coagulopathy had been corrected.

Dr Rogers looked at carotid endarterectomy. He stated that it was the commonest operation performed in the US and that most complications were surgical in nature.  He then went onto amputation and commented that though often seen as a trivial operation, it had appalling short and long term morbidity.   As a result, the Royal Liverpool Hospital had developed a care bundle for this type of surgery to try and improve outcome.  

Finally, Dr Rogers spoke about EVAR.   Increasingly they were being considered in emergencies for rupture although the place of EVAR in this situation is not yet established.   

Dr Rogers concluded his talk with his take-home message which was that there was very little in the way of evidence about the best anaesthetic technique for such patients and that experience often counts far more than recipes. He thought that team working and vascular anaesthetic on-call rotas were also helpful, as was the presence of more critical care beds, with therefore a higher nurse to acute bed ratio.   

‘Paediatric Emergencies and Transfers
Dr Peter Murphy, Alder Hey Hospital, Liverpool

Dr Murphy opened his talk by looking at the recent Care Quality Commission report highlighting alleged deficiencies in the operating theatre department at Alder Hey and commented about how little input from local healthcare professionals had been placed into the content of the report, particularly from within the operating department itself.
 
He then began to talk about his work with North West and North Wales Paediatric Transport Service (NWTS). He looked at the categories of referral which were for principally respiratory and neurological reasons.  Although there had been over a 1000 referrals in the 12 month period between April 2012 and March 2013, they had only made 614 transfers. Of those, the majority were infants under 1 year.

Dr Murphy looked at problems of the paediatric airway. He said that the majority of doctors involved in NWTS were paediatricians and therefore the local anaesthetists were almost certain to be the paediatric airway ‘experts’. He showed figures clarifying the chances of encountering a difficult intubation which were about 1 in 230 and a difficult mask ventilation of 1 in 5,000. He thought that the chances of encountering a “can’t intubate, can’t ventilate” scenario would be extremely rare. In the NWTS ENT regional audit between 2010-2013, 45% of the difficult airways encountered, were in children under 10 Kgs, and 35% were due to infective causes with a further 36%, due to congenital or structural lesions.   The incidence of failed intubation was 1.3% and three quarters of patients were intubated by the local team. Therefore Dr Murphy thought that there was far more a lack of confidence amongst anaesthetists rather than actual competence.

Dr Murphy looked at new cuffed endotracheal tubes which were increasingly being used and produced a better seal with no increase in post-extubation stridor. Dr Murphy gave some intubation advice which included a reminder about the presence of gastric stasis in sick children, the presence of ENT surgeons if the airway is anticipated as being difficult and consideration for the use of Ketamine in a child with shock. He thought that nasal intubation was better but certainly not essential in children being prepared for paediatric transfer.   

Dr Murphy discussed guidelines for the management of sepsis in children developed by NWTS centring on oxygen delivery through high flow facial oxygen, fluid resuscitation and inotrope/vasopressors. He stressed the importance of adequate fluid resuscitation. Trying to establish intravenous access may waste time and the latest type of intra-osseous needle can be equally effective and demonstrated their use in practice.

Dr Murphy then spoke about the sick baby, the causes of which could be categorised as being due to sepsis, cardiac or metabolic. He looked at the eight most common cardiac lesions. These included patent ductus arteriosus as well as atrial and ventricular septal defects, all of which resulted in a child without cyanosis.   In contrast cyanotic heart disease could be the result of pulmonary stenosis, Tetralogy of Fallot and transposition of the great arteries. The child who looks grey may have either coarctation of the aorta or aortic stenosis.    

Dr Murphy finished his talk by showing a new form that will hopefully simplify the mechanism by which doctors can visit and practice under supervision at Alder Hey Hospital to maintain their skills.

‘Obstetric Disaster’
Dr Clint Chevannes, Liverpool Women’s Hospital

Dr Chevannes started his talk by looking at maternal mortality which was currently 11.39 deaths per 100,000 maternity. This compared with a figure of approximately 1000 per 100,000 in Africa, and 200 per 100,000 in South America.

Dr Chevannes looked at the management of cardiac arrest in pregnant patients, and highlighted two additional factors that must be remembered; firstly, the manual displacement of the gravid uterus to avoid aorto-caval compression and secondly, the consideration of eclampsia as the reason for the cardiac arrest.  He looked at whether it was actually practical to tilt patients which led to compromise in CPR and worse-case scenario, the patient falling off the bed. He thought that manual displacement was far more practical and was absolutely vital for success in resuscitation. The causes of collapse would be the same in the parturient with the exceptional addition of eclampsia, potentially resulting in intra-cranial haemorrhage. He then went into more details about causes of collapse and in particular, the cause of hypovolaemia. This may be a sign of concealed uterine haemorrhage or relative hypovolaemia due to a dense spinal block. Secondly, hypoxia could occur far more quickly because of the greater oxygen consumption of the pregnant woman. Of the four Ts (thrombo-embolism, toxicity, tension pneumothorax and tamponarde),  he felt that thrombo-embolism, which may also be of amniotic fluid or air, were important to consider.  Secondly, with toxicity, this could be due to local anaesthetic, magnesium, opioid or anaphylaxis to any administered drugs. He then considered a couple of antidotes to toxicity, such as the administration of calcium in magnesium toxicity, and Intralipid to combat local anaesthetic toxicity.  

Dr Chevannes then asked the audience what they would do four minutes after cardiac arrest if there had not been a return of spontaneous circulation. The answer was to remove the baby as quickly as possible. He explained that a gravid uterus of more than 20 weeks gestation impaired venous return, reducing cardiac output secondary to aorto-caval compression and impaired effective CPR. Delivery of the foetus and placenta also reduced maternal oxygen consumption and helped both with more effective chest compressions and ventilation. He highlighted the importance of making this decision because without a peri-mortem Caesarean Section, the mother will certainly die, and by removing the baby, there would be a chance of both foetal and maternal survival.

Dr Chevannes turned his attention to obstetric haemorrhage which he said was the sixth leading cause of maternal death. This could be caused by placental abruption, uterine rupture, uterine atony, coagulopathy, placenta praevia, placenta acreta, and retained placenta. He said it was vital to be prepared for massive haemorrhage and stressed the importance of managing coagulation and reminded the audience that pregnancy was a hyper-coagulable state. He discussed the pitfalls of maternal haemorrhage which were delay in recognition followed by a failure to prepare, causing a delay in treatment of haemorrhage.    Death from haemorrhage in elective Caesarean Section is now a never event.    Dr Chevannes then went through placental abruption which may be concealed or visible although in 80% of patients there is vaginal bleeding. This condition can be associated with massive blood loss and an emergency hysterectomy may be necessary. He spoke about placental praevia which was present in 1:200 deliveries and was associated with painless vaginal bleeding as opposed to the painful bleeding of abruption. 

Dr Chevannes briefly discussed uterine atony and rupture.  He discussed pre-eclampsia and the importance of blood pressure control prior to delivery. When severe, complications such as oliguria, pulmonary oedema, HELLP syndrome and eclampsia can develop. Those women who develop eclampsia, should be treated immediately with magnesium and other anti-hypertensives if required, with the baby being delivered as quickly as possible. 

Dr Chevannes described amniotic fluid embolus which he felt was a misnomer and should be better called anaphylactoid syndrome of pregnancy, characterised by the sudden development of hypoxia, hypotension, cardiovascular collapse and coagulopathy. It had a mortality of 60 to 80% and there seemed no improvement in survival when the event occurred in the best equipped tertiary care centres.

In the final section, Dr Chevannes went over umbilical cord prolapse which could result in rapid foetal death due to asphyxia. With the baby being pushed upwards, the mother needs a Caesarean Section as quickly as possible, usually requiring a general anaesthetic. Finally, he looked at failed intubation, which was more common in obstetric patients and perhaps would be even less common if regional techniques had not failed in the first place. He demonstrated the use of ultrasound guided spinals to improve the success rate of this technique.

There was no time for questions.

The vote of thanks was given by Dr Anthony McCluskey, President of the Section of Anaesthesia of the Manchester Medical Society.

Ewen Forrest
Hon Secretary
22nd March 2014

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Last updated: 3 May, 2014 LSA