Download Standards for perioperative care of cardiac surgery patients

Guidelines for perioperative care of
cardiac surgery patients
August 2014
Contents
Introduction
Executive Summary
1. Pre-operative Care
1.1 Preoperative assessment
1.2 Pre-operative hydration
1.3 Premedication
1.4 Theatre planning and safety checks
2. Intra-operative Care
2.1 Anaesthesia and analgesia
2.2 Antibiotic prophylaxis
2.3 Haemodynamic monitoring
2.4 Haemodynamic targets
2.5 Intraoperative echocardiography
2.6 Coagulation management
2.7 Haemoglobin management
2.8 Blood glucose control
2.9 Cardiopulmonary bypass
2.10 Temperature control
2.11 Fast track recovery
2.12 Handover to CICU/ recovery
3. Organ dysfunction- perioperative strategies
3.1 Renal protection
3.2 Left ventricular failure
3.3 Right ventricular failure and pulmonary hypertension
3.4 Cerebral monitoring and protection
3.5 Myocardial protection
3.6 Atrial fibrillation
References
Appendices
1 Renal protection guideline
2 Haemodynamic monitoring
3 Cardiac output/ stroke volume guided therapy
4 Fast track recovery criteria
5 Coagulation management
6 Thrombelastography guided treatment of bleeding
7 Antimicrobial prophylaxis.
8 Cerebral oximetry
9 Guidelines for TOE reporting
Disclaimer:
We make every effort to provide you with guidelines based on the best evidence
existing. While science progresses and new practices develop we are continuously
working on updating our guidelines. Therefore we would like you to be aware that
some of the recommendations will become invalid and will be replaced by the new
ones.
These guidelines are applicable to most patients, but on occasions there may be
alternative management, which is more appropriate. Ultimately management of a
patient is based on all information processed by the responsible clinician according to
his knowledge and expertise.
Introduction
In recent years cardiac surgery has seen improvements in surgery, anaesthesia and
intensive care. Decreased mortality rates have been achieved despite complex surgery
in more elderly patients. The goal for the future is to improve quality of care further
and decrease morbidity.
Timely identification of patient comorbidities that increase the risk of perioperative
complications is vital. This allows more informed discussion with the patient, better
resource allocation and planning of strategies aimed at reducing risk.
Enhanced recovery programs in General Surgery „ERAS‟ have been successful in
reducing length of hospital stay. These employ a bundle of treatment strategies along
the patient‟s journey. Some of the same techniques are used already in cardiac surgery
patients and are nothing more than good, attentive anaesthetic care.
These guidelines are intended to improve consistency and quality of care. There is a
deliberate focus on preoperative and intraoperative care as the aim is to prevent
postoperative morbidities and reduce length of stay.
Consultant Cardiothoracic Anaesthetists:
Dr Alexander Dewhurst (lead)
Dr Jens Bolten
Dr Agnieszka Crerar-Gilbert
Dr Mark Edsell
Dr Nick Fletcher
Dr Bernie Liban
Dr Hanif Meeran
Dr Paul Quinton
Dr Frank Schroeder
Dr Vivek Sharma
Dr Dominic Spray
Dr JP Van Besouw
Dr Renate Wendler
Executive summary
Consultant anaesthetists should be involved in the preoperative assessment of cardiac
surgery patients at the earliest stage possible.
Estimated glomerular filtration rate (eGFR) must be recorded in preassessment. Clear
fluid is to be encouraged up to two hours prior to surgery. Intravenous fluid should be
prescribed preoperatively for patients at highest risk of renal dysfunction.
Excessive sedative premedication may adversely affect frail and elderly patients and
is to be avoided. Temazepam 10-20mg is a suitable alternative to morphine.
Anaesthetists must take an active role in theatre planning, preparation and team
briefing.
Prophylactic antibiotics must be given at induction of anaesthesia.
Intraoperative monitoring should be chosen according to standard criteria. The aim of
monitoring is to manipulate patient‟s physiology to reduce the risk of morbidities for
that individual. All but the lowest risk patients should have haemodynamic flow
monitoring.
Intraoperative echocardiography must be performed for all valve surgery and is
recommended for other complex cardiac surgery. Operators must have or be in the
process of attaining perioperative transoesophageal echo (TOE) accreditation. Images
must be stored and a report entered into the patient‟s notes.
Anaesthetic management of coagulation and transfusion is part of a structured,
multimodal, multidisciplinary approach to blood conservation. Point of care and/or
laboratory tests should guide treatment at all times. If used, Tranexamic acid should
be given as prophylaxis according to a regime adjusted for weight and renal function
for higher risk patients.
Blood glucose should be controlled between 5-10mmol/l. Dextrose must be given
with insulin infusions.
The anaesthetist is expected to work together with the perfusionist to ensure optimum
care for the patient during and on separation from cardiopulmonary bypass. Organ
perfusion and protection must be the focus of care.
Warming devices must be used as routine for all cardiac surgical patients so that
patients leave the operating room as near to normothermia as possible.
Lower risk patients are often suitable for early extubation in the cardiac recovery or
Cardiothoracic Intensive Care (CTICU). Anaesthesia should be tailored to achieve
this if appropriate.
There must be a documented handover of care to CTICU or Cardiac Recovery.
Risk of renal dysfunction is stratified into low, medium and high risk in a renal
protection guideline. Various strategies are suggested, but maintenance of hydration,
oxygen delivery and arterial pressure are paramount.
Patients at increased risk of perioperative cardiac failure should, where possible, be
identified, monitored and managed in anticipation of cardiac failure occurring. The
aim is to prevent haemodynamic instability. Right ventricular failure is particularly
problematic.
Atrial fibrillation prolongs hospital stay and consideration must be given to its
prevention. B-blockers must be reintroduced early if possible. Prophylactic
amiodarone with pacing should be considered for high risk patients.
1. Preoperative care
1.1 Anaesthetic assessment
Patient‟s scheduled for elective cardiac surgery are seen in outpatients by the
preassessment nurses. High risk patients and those with unusual problems should be
seen by or discussed with a consultant anaesthetist at the earliest possible opportunity.
Day of surgery admission patients should also have an anaesthetic review prior to the
day of admission.
Consultant cardiac anaesthetists should be available to discuss patients with the
consultant cardiac surgeons and preassessment nurses. Referral may be requested by
email [email protected], or telephone.
On admission, a specialist trainee or consultant anaesthetist will see the patient to
complete anaesthetic assessment and prescribe premedication. The assessment must
focus on clinical indicators and investigation results that have a bearing on patient
management and outcome. This is also an opportunity to inform the patient and
discuss perioperative risks. A plan of management must be made to avoid or
ameliorate complications.
1.2 Preoperative hydration
At St Georges, 20% of cardiac surgery patients suffer a 50% rise in serum creatinine
by the second postoperative day. Those with e GFR<90ml/min are most at risk.
Postoperative renal dysfunction after cardiac surgery is common and associated with
increased length of hospital stay. (See appendix renal protection).
Preoperative fasting guidelines encourage intake of clear fluid until 2 hours
preoperatively. Studies in general surgery and cardiac surgery have demonstrated
benefits from preoperative carbohydrate drinks. However, it is common for patients to
arrive in theatre nil by mouth for much longer than 2 hours.
All patients must be encouraged to drink clear fluid until 2 hours before
surgery. This should preferably be carbohydrate-containing fluid. Intravenous
fluid should be prescribed overnight for those particularly at risk of renal
dysfunction and/or with sliding scale insulin.
1.3 Premedication
Premedication is advantageous in reducing stress for patients with heart disease.
Traditionally 10mg morphine with 0.3mg hyoscine has been used. Morphine may
have cardioprotective effects in addition to sedation and analgesia, but excessive use
of opioids and sedatives in elderly patients can delay recovery. Hyoscine in particular
may cause confusion. Temazepam 10-20mg is suitable for more frail patients.
Premedication should be either:
a) 10-20mg of temazepam orally, or
b) morphine plus cyclizine intramuscularly –avoid morphine in the frail or
over 75 years of age.
1.4 Theatre planning, preparation and safety checks
Improved planning and preparation on the evening before surgery will make the
morning start less hurried and more efficient.
The consultant anaesthetist for each theatre should be marked on the theatre
whiteboard the evening before surgery. It is useful to discuss monitoring and
equipment needs with the ODPs at this time e.g. TOE, pulmonary artery catheter
(PAC), infusions. Special equipment can also be requested on the Anaesthesia
equipment whiteboard adjacent to the blood fridge.
On the morning of surgery surgeons, anaesthetists, intensivists, perfusionists and
theatre staff must meet at 07.55 am to discuss the days work. Preoperative checklists
must be completed as per the WHO surgical safety checklist.
2. Intraoperative Care
2.1 Anaesthesia and analgesia
To enable theatre ODPs to set up anaesthetic rooms each day, the drugs used by all
anaesthetists should be as standard as possible.
The following is the standard set of drugs to be drawn up for each patient unless
others are specified:
Anaesthetic drugs
Midazolam 1mg/ml or diazepam 10mg/2ml for sedation during line insertion
Fentanyl 1mg
Propofol for induction
Rocuronium 100mg
Vasoactive bolus drugs
Metaraminol 10mg/10ml
Atropine 0.6mg/ 5ml
Infusions
GTN 50mg/50ml
Propofol 1% 50ml
Others according to need
Coagulation management
Heparin 20000u plus additional available for 300-400u/kg
Protamine available but not drawn up
Tranexamic acid 2g (most of the cases but not for OPCAB or low risk of
bleeding)
Maintenance of anaesthesia
Pre and post CPB:
Isoflurane in oxygen+air.
On CPB:
propofol 3mg/kg/hr or isoflurane 0.5-1% via the oxgenator with
exhaust concentration monitoring by the anaesthetist.
2.2 Antibiotic prophylaxis
Prophylatic antibiotics reduce the incidence of postoperative infections, but only if
administered before or at the start of surgery. The theory being that there must be a
concentration of drug at the tissue level at the time of incision.
Cefuroxime 1.5g iv should be given at induction of anaesthesia, prior to
urinary catheterisation. Patients with Penicillin anaphylaxis or cephalosporin
allergy should be given iv Vancomycin 15 mg/kg over 60 minutes prior to
incision and iv Ciprofloxacin 400 mg at induction. In patients with bacterial
endocarditis microbiology should be consulted.
(Refer to Antimicrobial prophylaxis guidelines )
2.3 Haemodynamic monitoring
All patients have central venous and invasive arterial pressure monitoring as standard.
Ultrasound must be used to guide central venous access. Cardiac output should be
monitored in complex cardiac surgical cases. Indications for haemodynamic
monitoring by device are listed below. In certain circumstances more than one
monitoring device is indicated such as PAC and TOE in mitral valve surgery
PAC + Vigilance CO monitor
Poor left or right ventricular function
Pulmonary hypertension
Mitral valve surgery (particularly valve replacement and in patients
with compromised LV function)
Tricuspid valve surgery
For monitoring cardiac output in theatre and postoperatively on
intensive care
LiDCO
Stroke volume and cardiac output optimisation when there is no PA
catheter.
TOE
All valve surgery
Poor ventricular function
Major aortic surgery
Closure of atrial or ventricular septal defects
Removal of intracardiac masses
(See intraoperative echocardiography)
Cerebral oximetry
Aortic arch surgery, particularly involving deep hypothermic
circulatory arrest.
Significant carotid stenosis (evidence to support this use is not
established)
(See cerebral oximetry protocol )
2.4 Haemodynamic targets
Outcome from major surgery is poorly associated with pressure variables such as
arterial blood pressure. Measurements of flow and tissue perfusion correlate much
better with morbidity and mortality. Individualised goal directed therapy is associated
with reduced length of hospital stay in cardiac surgery.
Flow
Stroke volume optimised with fluid challenges (see algorithm)
Cardiac index >2.2 l/min/m2, improving indices of organ perfusion.
Organ perfusion
Lactate <2mmol/l
Urine output >0.5/ml
SVO2>70%
Pressure
Arterial BP>100mmHg systolic, MAP>60mmHg
Higher in patients with hypertension, significant carotid disease or
renal impairment e.g. systolic >120mmHg or MAP 70-80
rSO2 (cerebral saturations)
Maintain cerebral saturations within 20% of baseline and above the
critical desaturation point of 40%
2.5 Intraoperative echocardiography
Intraoperative TOE must be used in accordance with ASA practice guidelines for “
adult patients without contraindications, TEE should be used in all open heart (e.g. ,
valvular procedures) and thoracic aortic surgical procedures and should be considered
in coronary artery bypass graft surgeries to: (1) confirm and refine the preoperative
diagnosis, (2) detect new or unsuspected pathology, (3) adjust the anesthetic and
surgical plan accordingly, and (4) assess the results of surgical intervention.”
Complications of TOE although rare include: oesophageal perforation, oesophageal
injury, haematoma, laryngeal palsy, dysphagia, dental injury, or death. Probes should
only be inserted by experienced anaesthetists to ensure excessive force is not used.
Insertion under direct vision recommended.
Operators should be accredited in perioperative TOE, or be in the process of gaining
accreditation. The ECG leads should be attached. Images must be saved and a written
report placed in the patient‟s notes along with a record of sterilisation.
The report must include the following:
Quantification of global and regional LV function
An Assessment of RV function
Quantification of any valvular pathology
Measurements of atrial size
Comment on the adequacy of de-airing
Other information pertinent to the surgery and pathophysiology
( refer to ACTA guidelines for TOE reporting)
If TOE is indicated but not available due to lack of equipment then consideration must
be given to cancellation or postponement.
CTICU has equipment for continuous postoperative TOE monitoring suitable for
patients likely to have ongoing, complex haemodynamic instability.
Absolute contraindications to TOE include: previous oesophagectomy, and
oesophagogastrectomy. Some consider as absolute contraindications also :
oesophageal stricture, tracheoesophageal fistula, postoesophageal surgery, and
oesophageal trauma. Relative contraindications are : Barrett oesophagus, hiatus
hernia, large descending aortic aneurysm, and unilateral vocal cords paralysis,
oesophageal varices, postradiation therapy, previous bariatric surgery, Zenker
Diverticulum and dysphagia. ( refer to ASA practice guidelines)
2.6 Coagulation management
Heparin dose for CPB is 300-400u/kg Target ACT for CPB cases is 400s, for off CPB
cases 300s. For long CPB cases (>2hrs) there may be some benefit from using higher
doses of heparin and higher target ACTs to suppress subclinical thrombin generation.
Total heparin greater than 500u/kg is likely to lead to postoperative rebound
heparinisation requiring additional protamine. Heparin rebound occurs in around 30%
of patients and is the most common and significant coagulopathy detected on CICU.
Additional protamine is simple to administer and will reduce bleeding and
transfusion.
Patients at high risk for postoperative bleeding should have thrombelastography
(TEG) monitoring intraoperatively and postoperatively (see TEG handbook on
CTICU and TEG treatment guideline). This will include a baseline sample with the
first blood gas and ACT, post protamine samples and 1-2hrs post op on ICU.
Laboratory PT, APTT and fibrinogen samples should be sent before leaving theatre.
It should be noted that standard TEG will not show platelet dysfunction due to aspirin
and clopidogrel. TEG platelet mapping should be considered in these cases and/or
platelets ordered. Limiting factors at present are the cost and availability of the
platelet mapping kit. Multiplate is another point of care platelet function test which is
going to be available for perioperative use in the near future.
Tranexamic acid reduces bleeding in cardiac surgery, but is not necessary in low risk
cases such as off-pump CABG. It is excreted by the kidneys with a half life of 2hrs.
Large doses are associated with non-ischaemic seizures. Pharmacological studies have
demonstrated 80% inhibition of plasminogen after a 1g intravenous dose in normal
size adults. Spinal fluid concentration is approximately 30% of plasma concentration.
Seizures have resulted from accidental spinal injection. Therefore, in long, high risk
cases a continuous infusion should be used to maintain therapeutic plasma levels, but
high peaks in plasma concentration may risk seizures. Consideration must be given to
limiting the total dose, particularly in the context of reduced renal function because
accumulation will occur.
See appendix 6 for dose regimes.
All surgical patients must have a TEG performed on CTICU 1-2hrs
postoperatively to detect heparin rebound.
All except the lowest risk patients must have intraoperative TEG monitoring.
Tranexamic acid should be used for most patients according to a dose regime
adjusted for weight and renal function
2.7 Haemoglobin management
Although anaemia is associated with worse outcome, allogeneic blood transfusion is
also associated with worse outcome following cardiac surgery. A moderate degree of
anaemia is preferable to allogeneic transfusion and for this reason a target
haemoglobin of 8g/dl is used. Autologous „cell saver‟ blood is exempt from this limit
as it returns the patient‟s own red cells and has better oxygen delivery characteristics.
On CPB a haemoglobin of 6-7g/dl may be tolerated. Patients of small stature with a
low baseline haemoglobin may immediately fall below the minimum haemoglobin
due to haemodilution on CPB. Blood can be added to the pump prime or pump prime
reduced for such patients.
Anaemia must be detected preoperatively and corrected with iron supplements when
possible. Some investigators have used preoperative intravenous iron and
erythropoietin to successfully reduce red cell transfusion.
RBC transfusion triggers:
Hb <8g/dl pre and post CPB
Hb <6-7g/dl on CPB
Autologous blood always reinfused
2.8 Blood glucose control
Hyperglycaemia is associated with worse outcome following cardiac surgery or in
critical illness. Infections are increased and renal injury may be worsened.
Blood glucose should be controlled between 5-10mmol/l. Above 10mmol/l an
insulin infusion should be started plus dextrose 50% 5-10ml/hr.
Diabetic patients should begin their surgery on insulin and dextrose infusions
2.9 Cardiopulmonary bypass
The cardiac anaesthetist must work together with the perfusionist to manage the
patient on CPB. If anaesthesia is provided with isoflurane on CPB, this is via the CPB
oxygenator, but remains the responsibility of the anaesthetist. For straightforward
cases minimal input from the anaesthetist is required, but for complex cases a close
teamwork approach is needed. Issues for discussion include cerebral oximetry targets,
pump flow, vasoconstrictor/dilator use, haemofiltration, acid-base management and
coagulation tests.
In the Good Practice Guide for Clinical Perfusion at St Georges, drugs and solutions
are divide into three groups. Some are given as standard by the perfusionists, others
require supervision by the anaesthetist or surgeon.
2.10 Temperature control
Hypothermia is used during cardiac surgery on CPB for cardiac and cerebral
protection. Patients are warmed to 37 oC before separation from bypass. The rate of
rewarming should be gradual and temperature must not exceed 37 oC, also for organ
protection. Conversely hypothermia is associated with delayed recovery, infection and
impaired coagulation. Therefore normothermia must be the goal when not on CPB. A
fluid warmer and Bair Hugger blanket must be used routinely during rewarming and
post CPB to prevent hypothermia. For non-CPB cases warming must be used
throughout and may even be commenced in the anaesthetic room.
2.11 Fast track cardiac recovery
Low risk patients may be taken to the cardiac recovery area from theatre for early
postoperative extubation and discharge to Benjamin Weir ward the same evening (see
Fastrack selection guideline). Anaesthesia for these patients should be geared towards
faster recovery, using shorter acting agents where possible and, of course, warming
devices. Opioid analgesia must be adequate, but not excessive. For example,
morphine premedication plus 1mg of fentanyl intraoperatively may delay extubation
in a small elderly patient. The same approach should be used for lower risk patients
destined for CTICU postoperatively.
It should be remembered, however, that fast track recovery is mainly for the benefit of
the hospital, minimising intensive care use. Patient safety is paramount, so over
ambitious fast tracking must be avoided. Those patients who fail ward discharge
criteria are admitted to CTICU.
Whilst in the recovery area, medical supervision of care must be provided at regular
intervals by the theatre anaesthetists. If this is not possible, there must be
communication with the CTICU team who may supervise.
2.12 Handover to CTICU and recovery
On admission to the CTICU or cardiac recovery the responsible anaesthetist must
handover care to the CTICU/ recovery nurse and the CTICU doctor. Along with a
brief summary of the medical history and intraoperative care there must be a
suggested plan for ongoing management. Pertinent intraoperative anaesthetic and
surgical problems, echocardiography findings, coagulation management and
haemodynamic targets must be included. There is a section of the anaesthetic chart for
documenting this process.
3. Organ dysfunction- perioperative strategies
3.1 Renal protection
At St Georges, 20% of cardiac surgery patients suffer a 50% rise in plasma creatinine
by postoperative day 2. Studies from other centres have demonstrated increased
length of hospital stay associated with acute kidney injury (AKI). The most significant
risk factors are reduced baseline renal function, diabetes, hypertension and age over
70 years. Those at risk are often unrecognised as plasma creatinine may be within
normal limits although estimated glomerular filtration rate (eGFR) is significantly
reduced. Many strategies have been investigated for renal protection without
conclusive success. Only good hydration, optimisation of cardiac output and adequate
arterial pressure can be strongly recommended.
Other available strategies are unproven. Sodium bicarbonate has been associated with
reduced renal injury, but only in a pilot study. However, maintenance of normal pH
and correction of hyperchloraemic acidosis are theoretically also good reasons for
giving bicarbonate. Excess chloride administration with normal saline-based fluids
has been associated with an increased incidence of AKI.
Dopamine has no proven renal protective effect, but at a low dose (2-4mcg/kg/min) is
useful for increasing cardiac output, heart rate and arterial pressure. However
Dopamine increases risk of arrhythmias particularly in patients with impaired LV
function. Noradrenaline increases aterial pressure, has a mild inotropic effect and is
the logical choice for vasodilated patients. Haemofiltration on bypass controls fluid
balance, can increase oxygen delivery by haemoconcentration and may reduce plasma
cytokines. There is also some evidence of a beneficial effect of intraoperative
haemofiltration on postoperative bleeding.
Frusemide blocks the Na/K pump and, in theory, therefore reduces renal oxygen
consumption. However, despite its widespread use there is no evidence that frusemide
is a useful agent for prevention of AKI. Indeed, the reassuring diuresis produced can
distract from maintaining adequate circulatory volume and blood pressure. Cortical
vasodilation observed with frusemide may divert blood flow away from the more
vulnerable renal medulla. Frusemide induced diuresis may help to control fluid
balance and avoid haemofiltration in established renal injury. This must not be
confused with prevention of AKI.
All patients must have eGFR calculated and recorded preoperatively. Those
with eGFR<90ml/min are at increased risk of AKI.
In addition to oral hydration, preoperative intravenous fluid should be given to
patients with a high risk of AKI e.g. eGFR<50ml/min.
All patients with increased renal risk should have intraoperative and
postoperative cardiac output monitoring with MAP maintained 70-80mmHg.
For patients at high risk of AKI (eGFR 30-50ml/min) particular attention is
required to ascertain adequate oxygen delivery and high MAP. This may
require for use of vasoconstrictors. Also haemofiltration on CPB and may be
considered.
See renal protection guidelines.
3.2 Left ventricular failure
In the setting of elective surgery, it is unusual for left ventricular (LV) failure to occur
unexpectedly following cardiopulmonary bypass (CPB). Modern myocardial
protection with cardioplegia allows a long cross-clamp period with little reduction in
LV function. Post CPB LV failure can usually be predicted from preoperative
dilatation, reduced function or ongoing myocardial ischaemia. It should be noted that
LV dysfunction is underestimated in the presence of severe mitral regurgitation.
Unexpected LV failure following CPB may follow surgical difficulties.
Cardiac output (CO) monitoring should be used for patients with reduced LV
function. A pulmonary artery catheter is strongly recommended for patients with poor
LV function, whereas less invasive methods such as LiDCO may be appropriate for
mild or moderate LV dysfunction (see monitoring standards).
The goal is to prevent organ failure. So, fluid, inotropic and vasoconstrictor therapy is
guided primarily by measures of organ perfusion (e.g. lactate, urine output). Flow
measures such as CO and stroke volume are secondary. Pressure targets are less
important than flow because targeting arterial blood pressure alone by
vasoconstriction is often at the expense of organ perfusion, especially in patients with
reduced LV function. Central venous pressure reflects right heart filling pressure but
its use as a sole target is illogical. Very high venous pressure causes congestion and
reduced perfusion.
In patients without CO monitoring, LV failure must be suspected when there is
persistent evidence of hypoperfusion or hypotension despite fluid challenges. CO
monitoring must then be instituted. Echocardiography should be performed to
evaluate cardiac function.
When starting inotropic therapy, low dose dopamine (<5mcg/kg/min) may suffice for
patients with mild LV impairment. One has to be mindful of the proarrhythmogenic
effects of Dopamine. Milrinone is first choice for patients with moderate to severe LV
impairment and benefits diastolic as well as systolic function. Noradrenaline will be
required to counter systemic arterial vasodilation. More severe LV failure can be
managed with the addition of an intra-aortic ballon pump. Levosimendan should also
be considered, but its use is restricted due to cost.
Guideline for the management of LV failure:
Diagnosis and monitoring
Evidence of hypoperfusion (e.g. raised lactate, low urine output, low
CO) unresponsive to fluid.
Echocardiography, CO monitor
Treatment, as advised by Consultant
1. Mild: Low dose dopamine or milrinone infusion 250750ng/kg/min
Monitor with LiDCO or PAC
2. Moderate: Milrinone half loading (25mcg/kg) dose plus infusion,
noradrenaline
(NA) to maintain MAP, monitor with PAC
3. Severe: Full dose milrinone (50mcg/kg) and infusion, NA, +/IABP, consider levosimendan (consultant use only), monitor with
PAC
3.3 Right ventricular failure and pulmonary hypertension
Aetiology: This highly challenging problem is most commonly seen in patients with
known right ventricular (RV) dysfunction, pulmonary hypertension and undergoing
tricuspid valve repair surgery. Transient acute RV dysfunction also commonly occurs
due to coronary air embolus on separation from cardiopulmonary bypass.
Clinical presentation: Right heart pressures (CVP, PA) are high compared with
systemic pressure and cardiac output is low.
Therapeutic aims: The principle aims of treatment are to improve the right heart
contractility and reduce pulmonary vascular resistance. While CVP needs to be
slightly higher than usual, excessive right heart filling pressure results in RV
distension and failure followed by liver dysfunction. Thus, fluid therapy beyond a
certain point may worsen the situation.
Transoesphageal echocardiography and a PA catheter are invaluable diagnostic and
monitoring tools for right ventricular failure. Milrinone is used as the main
pharmacological treatment for its inotropic and pulmonary vasodilator effects.
Systemic pressure is maintained with noradrenaline to balance the systemic
vasodilation caused by milrinone. Vasopressin may be a useful additional
vasoconstrictor as it has less pulmonary vasoconstrictor effect. Dopamine and
adrenaline may added to increase RV contractility. Other pulmonary vasodilator drugs
to consider are GTN, sildenafil and prostacyclin.
A higher than standard heart rate (90-100/min) often increases cardiac output as right
ventricular stroke volume is likely to be poor.
Consideration should be given to the patient‟s ventilation as raised intrathoracic
pressures or hypercarbia increase pulmonary vascular resistance.
The impact of treatment changes can be tracked visually using continuous TOE
monitoring alongside quantitative haemodynamic measurements such as CO and BP.
An intra-aortic ballon pump can provide mechanical support in extreme cases.
Guideline for RV failure management:
Diagnosis and monitoring
Recognise risk factors in advance and anticipate RV dysfunction.
Early diagnosis of acute RV failure: ↑↑CVP, ↓ CO, ↓BP
Monitor with continuous TOE (Imacor), PAC, CO
Treatment, as advised by Consultant:
1. Mild
Milrinone, noradrenaline, GTN
Control pCO2 <5kPa, limit PEEP to 5cmH2O
Consider muscle relaxation
2. Moderate
Add adrenaline to↑CO 0-0.1mcg/kg/min
Vasopressin 1-4u/hr if MAP <60mmHg
3. Severe
IABP, Sildenafil, selective pulmonary vasodilators such
as intravenous or nebulised prostacyclin or NO.
3.4 Cerebral monitoring and protection
During cardiac surgery the brain is obviously protected principally by maintaining
oxygenation, blood flow and pressure. Hypothermia and anaesthesia provide
additional protection. Thiopentone and steroids were traditionally employed during
DHCA but they are no longer recommended
Depth of anaesthesia may be monitored using BIS.
Cerebral oxygenation can be monitored with near infrared spectrometry (NIRS). Used
alongside a treatment algorithm this may enable preservation of cerebral oxygenation
during high risk cardiac surgery (see NIRS guideline). NIRS may be considered in the
following cases:
Surgery of aortic arch
DHCA
Patients with significant carotid artery stenosis
Research participants
Cerebral function monitoring (BIS)
For targeted administration of anaesthesia to patients at high risk of awareness
or excess anaesthesia.
3.5 Myocardial protection
Experimental studies have suggested various treatments to reduce the myocardial
injury associated with cardiac surgery. These may be protective by their actions on
adrenoreceptors, ischaemic preconditioning mechanisms, coronary blood flow,
oxidative stress and so on. It is difficult to conclude that these effects have a
significant influence on outcome. However, what evidence there is supports the use of
some of the common tools of cardiac anaesthesia.
Treatment
Mechanism
Beta blockers
Isoflurane
Propofol
Morphine, fentanyl
Insulin
Statins
Prevention of arrythmias
Anaesthetic preconditioning
Free radical scavenging
Anaesthetic preconditioning
Metabolic and inotropic effects
Endothelial protection, antiinflammatory
3.6 Atrial fibrillation
Postoperative atrial fibrillation (AF) occurs in 30% or more of patients following
cardiac surgery and is associated with increased length of stay. AF following cardiac
surgery is promoted by systemic inflammation and increased catecholamine levels.
Predisposing factors include previous AF, valve surgery and greater surgical
manipulation of the atria. Incidence peaks around postoperative day two to three.
Various pharmacological and other strategies have been investigated to prevent AF.
Of these, pre and postoperative B-blockers are most strongly recommended. Few
studies have investigated intraoperative B-blockers, but they are often useful. A
perioperative course of amiodarone is suggested for B-blocker intolerant or more high
risk patients. Temporary atrial pacing protects against bradycardia in patients on Bblockers and amiodarone. Early postoperative statins may reduce AF and have other
beneficial effects. There is inconclusive evidence for the use of steroids and insulin
with glucose.
B-blockers must be continued preoperatively and reintroduced as soon as
possible postoperatively. It is reasonable to use an intravenous B-blocker to
control intraoperative heart rate and rhythm.
A perioperative course of amiodarone should be considered for patients at high
risk of developing postoperative AF. Temporary pacing must also be attached.
References
Modernising care for patients undergoing major surgery: a report by the Improving Surgical Outcomes
Group 2005
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Appendices
1. Guideline for renal protection in Cardiac Surgery patients
Low risk
Medium risk
High risk
ESRF/ CRF
eGFR>90 +/- one
eGFR 50-90 or
eGFR 30-50
eGFR<30
risk factor
> two risk factors
↓
/on dialysis
↓
↓
↓
Preoperative
Nephrology review,
dialysis plan
Oral fluid + iv fluid
with sliding scale for
diabetics
Iv fluid
Iv fluid if not anuric
Oral fluid
MAP 70-80
Pre CPB
Intraoperaative
MAP>80mmHg
Standard therapy
MAP 70-80
Vasopressor/ inotrope
vasopressor / inotrope
CO/SV guided
protocol
CO/SV guided protocol
CO/SV guided
protocol
MAP>80mmHg
MAP 70-80mmhg
On CPB
Standard therapy
MAP 70-80mmHg
haemofiltration
haemofiltration
correct ↑Cl- acidosis
with NaHCO3
correct ↑Cl acidosis
with Na HCO3
correct ↑Cl acidosis
with NaHCO3
Hb>6
Hb>7
Hb>7
MAP>80
Post CPB
MAP>70mmHg
Standard therapy
MAP>70mmHg
vasopressor/inotrope
vasopressor/ inotrope
CO/SV guided
protocol
CO/SV guided protocol
CO/SV guided
protocol
Guideline for renal protection in cardiac surgery: notes
Risk stratification for renal dysfunction
In addition to reduced eGFR, the following are associated with increased risk: hypertension, age > 75
years, diabetes on insulin. Patients are therefore grouped into low, medium and high risk according
to eGFR plus additional risk factors. A fourth group comprises those with end stage renal failure
(ESRF) or chronic renal failure (CRF). eGFR is calculated from plasma creatinine, weight and age and is
a more useful marker as patients with plasma creatinine within the normal range often have
significantly reduced renal function.
Preoperative oral/ intravenous fluids
Patients must be encouraged to drink clear fluid until 2 hours before surgery. This should be 500mls
of carbohydrate drink. Intravenous fluid should be crystalloid given overnight preoperatively at
80mls/hr and may be in addition to oral fluid. Diabetic patients normally on insulin will receive
intravenous fluid with sliding scale insulin.
CO/SV guided protocol
Intraoperative fluid administration using a stroke volume(SV) or cardiac output(CO) algorithm to
optimise cardiac output is recommended for all but the lowest risk patients. A LiDCO or pulmonary
artery cather (PAC) is required (see haemodynamic protocol). A cardiac index (CI)>2l/min/m2 is a
reasonable minimum target. Inotropic therapy with dopamine or milrinone may be required in
addition to fluid.
Inotropes and vasopressors
Dopamine may be used as an inotrope to raise CI>2l/min/m2 2-5mcg/kg/min and also has a diuretic
effect, but milrinone should be used for moderate or severe ventricular dysfunction. Noradrenaline
must be considered for patients with a below target arterial pressure and adequate cardiac output.
Frusemide
Frusemide causes excessive postoperative diuresis resulting in hypovolaemia with a falsely reassuring
urine output. As this will worsen renal injury frusemide is undesirable as a prophylactic agent.
Haemofiltration
Normovolaemic haemofiltration should be performed continuously on cardiopulmonary bypass(CPB)
for high risk and ESRF/CRF patients.
Hyperchloraemic acidosis
Hyperchloraemia (↑Cl-) results in a non-lactic acidaemia and is associated with reduced renal blood
flow. Sodium bicarbonate should be given to correct to normal pH/ base excess. Excessive use of
saline based fluid or Ringer’s solution should be avoided.
2. Haemodynamic monitoring for cardiac anaesthesia
Indications for haemodynamic monitoring by device are as follows:
Arterial line and central line
All patients
Pulmonary artery catheter + Vigilance CO monitor
Poor left ventricular function
Pulmonary hypertension
Known or suspected poor right ventricular function
Mitral valve surgery with any of the above
Surgery involving the tricuspid valve
For monitoring pulmonary artery pressure and cardiac output in theatre
and postoperatively on intensive care
LiDCO
Stroke volume and cardiac output optimisation when there is no PA
catheter as part of a renal protection strategy.
Transoesophageal echocardiography
All valve surgery
Poor ventricular function
Major aortic surgery
Closure of atrial or ventricular septal defects
Removal of intracardiac masses
(See intraoperative echocardiography)
Cerebral oximetry
Major aortic surgery, particularly involving DHCA
Significant carotid stenosis
(See cerebral oximetry guideline)
3. Cardiac output/ stroke volume guided therapy
Haemodynamic targets
Organ perfusion
Lactate<2mmol/l
Urine>1ml/kg/hr
Flow
CI>2.2l/min/m2
Pressure
MAP 60-80mmHg
(within 20% of baseline)
O2 delivery
Hb 8g/dl
SpO2 >95%
pO2>10
SvO2>70%
Measure CO/ SV
Consider HR
Fluid challenge
250mls in <5mins
CO↑ by >10%
SV ↑ by >10%
Yes
No:
Adequate CO, low BP
CI >2.2
Vasoconstrictor:
Noradrenaline for MAP
60-80mmHg
Poor CO/ vasoconstricted
CI<2.2
Inotrope:
Milrinone/ dopamine
Reduce vasoconstrictor?
Review at 5 minutes
3.4.
Fast track criteria
Preoperative Criteria:
Yes
No
Euroscore
Age <75
First-time operation
Operation:
CABG
MiDCAB
ASD closure
AVR + CABG (depending on bypass time)
Body mass index <30
Creatinine <150 umol/l
No MI within last month
Normal lung function tests
Recent Dual anti-platelet therapy for ACS
Intraoperative criteria:
No significant unexpected intraoperative problems
End of surgery before 2pm
Bleeding controlled
No inotropic support required other than dopamine <5mcg/kg/min or
noradrenaline <0.1mcg/kg/min
Discharge to ward:
Extubated by 6pm
Review by Consultant Anaesthetist
Acceptable arterial blood gases, pO2>10, lactate<2, BE better than -4, Hb 8
No inotropic support required other than dopamine <5mcg/kg/min or
noradrenaline <0.1mcg/kg/min
Urine output >0.5ml/kg/hr
Bleeding<100ml/hr
5. Coagulation management for cardiac surgery
Heparin management:
Operation
Initial heparin dose
OPCAB
150u/kg
All CPB cases
300-400u/kg
Target ACT
300s
400-480s
Protamine dose regime:
Initial protamine dose 1mg for every 100u of initial heparin dose to return ACT
post cpb
to within 10% of baseline, and/or TEG r time equal on
heparinase and non-heparinase test samples.
Post operative
If total heparin (including on cpb)>500u/kg, give extra
protamine for heparin protamine at 1-3hrs post op guided by TEG or ACT
rebound
Prevention of bleeding and TEG monitoring:
Operation
Prophylaxis
OPCAB
None
CABG or AVR with
Tranexamic acid
no additional bleeding
risk
All other cases
Tranexamic acid
Uraemic patients
Tranexamic acid
DDAVP 0.3mcg/kg over
30min on rewarming
TEG monitoring
None
1-2hr post op
Baseline pre heparin
Post protamine
1-2hrs post op
Baseline pre heparin
Post protamine
1-2hrs post op
Tranexamic dose guide according to body weight and renal function:
eGFR(ml/min)
>90
50-90
<50
Loading dose
Infusion rate
Maximum total
e.g. for a 70kg
patient
15-30mg/kg
7-10mg/kg/hr
100mg/kg
1-2g + 5-7 mls/hr
Max 7g
15-30mg/kg
4-7mg/kg/hr
70mg/kg
1-2g + 3-5mls/hr
Max 5g
15-30mg/kg
0-4mg/kg/hr
40mg/kg
1-2g + 0-3mls/hr
Max 3g
6. Thrombelastography guided treatment
of bleeding
Bleeding excessively?
no
yes
Observe.
Transfuse red
cells if
Hb<8g/dl
TEG, PT, APTT,
fibrinogen.
Reassess, and if still
bleeding treat as
follows:
TEG heparinase R
value normal, but
plain R >9mins
Protamine 50mg
Platelet count <80
MA< 50mm
MA<42mm
Recent aspirin or clopidogrel and
platelets and MA normal: platelet
mapping
Platelets 1 pool
Platelets 2 pools
R value >9mins
PT>1.5 normal
FFP 4u
(10-15mls/kg)
LY30>7.5%
and
R >4mins
MA<74mm
Fibrinogen<1.0g/l
Normal TEG and
laboratory tests
Consider
antifibrinolytic if
bleeding
10u
cryoprecipitate
Surgical cause for
bleeding likely
Repeat TEG® and lab tests after treatment
7. Surgical antibiotic prophylaxis
Surgical
intervention
“Routine”
Prophylaxis
Penicillin anaphylaxis or
cephalosporin allergy
Patients known to be MRSA
colonised
CABG
Valve
replacement
iv Cefuroxime 1.5g at
induction then 2 further
Doses of 750 mg at 8 & 16 hours
iv vancomycin 15mg /kg infusion
60 min prior to incision
followed by 1g 12 hours later *
+single dose iv ciprofloxacin
400 mg at induction
iv vancomycin 15mg /kg infusion
60 min prior to incision
followed by 1g 12 hours later *
+ iv cefuroxime 1.5g at induction
then 2 further doses of 750mg at 8
&16 hours
iv Cefuroxime 1.5g at
induction then 4 further
Doses of 750 mg at 8 hourly
intervals
iv vancomycin 15mg /kg infusion
60 min prior to incision
than 2 further doses of 1g at
12hhrly intervals*
+single dose iv ciprofloxacin
400 mg at induction
iv vancomycin 15mg /kg infusion
60 min prior to incision
followed by further doses of 1g at
12 hourly intervals *
+ iv cefuroxime 1.5g at induction
then 4 further doses of 750mg at 8
hourly intervals
Repeat doses of antibiotics should be given in prolonged surgery at the following intervals is renal function is normal:
Cefuroxime :750mg 4 hourly
Ciprofloxacin: 400mg 8 hourly
Vancomycin: 1g 12 hourly
Repeated doses may also be required following fluid resuscitation after severe blood loss.
* Post operative Vancomycin dosing should be adjusted or omitted in patients with renal impairment.
Written by : Laura Whitney ( Antibiotic Pharmacist), Aodhan Breathanach ( Consultant Microbiologist), Mazim Sarsam( Consultant Cardiac
Surgeon
Review date: August 2013
8. Guidelines for the use of Cerebral Oximetry (NIRS) during Cardiac Surgery
Background
The Invos cerebral Oximeter uses near-infrared spectroscopy to give a global saturation value for cerebral tissue beneath the probe. The
regional saturation represents the proportion of oxygenated haemoglobin in arterial, venous and cerebral tissue. As normal values vary widely,
the Invos oximeter is licensed as a trend monitor making the assessment of baseline values essential (see below).
Suggested Patients/cases
Surgery of aortic arch
DHCA
Patients with significant carotid artery stenosis
Research participants
Use of the Invos Cerebral Oximeter
Clean the skin of the forehead using alcohol swab or similar
Place oximetry optodes over each fronto-temporal area
Attach optodes to the oximeter and switch on.
Select new patient
wait for a stable signal and press set baseline
Note: Baseline values should be taken prior to induction of anaesthesia and ideally prior to benzodiazepine sedation. After baseline values
taken, monitor can be disconnected and brought through to the theatre for use during induction.
During the case, if time allows, events can be marked by pressing the events key and selecting the appropriate event (adding events
helps to better describe the course of the procedure and are included in the printed summary)
Set alarms if desired. The oximeter will automatically alert you by changing colour (to red) if the rSO2 falls by greater than 20% of the
baseline.
After induction of anaesthesia, consider conducting a test of cerebro-vascular reactivity by hyperventilating the patient for a short time
and observing changes in rSO2
If cerebral desaturation occurs, follow suggested algorhythms attached to monitor (see below).
At end of case, a summary can be printed up by exporting the appropriate file recorded on the memory stick. Instructions for exporting
files can be found in the pdf document on the memory stick.
Complete the audit sheet attached to the oximeter
Treatment guidelines for the use of cerebral oximetry
9. Guidelines for TOE Reporting
( ACTA, 2008 )
A. Crerar-Gilbert, D. Greenlagh, H. Skinner
Overall requirements for TOE logbook report for the purpose of accreditation:
1. Report should be comprehensive. Focussed report reporting solely on the anatomy in question for example ASD is not sufficient for
purpose of the Logbook.
2. If exam is perioperative or preintervention it should include pre and postoperative findings. Pre and postoperative exam will be
considered as one report and not as two separate reports.
3. Patients names should be concealed to protect confidentiality
4. Assessors names should not be made known to those submitting the log book
5. Tick box format is not the preferred one, as it frequently does not make an allowance for sufficient narration.
Minimum requirements for the log book content:
Left Ventricle
LV cavity size and systolic function. Quantified if impaired.
Diastolic function assessment particularly if for CABG desirable. Mitral inflows & Pul vein flows +/- tissue Doppler +/- colour mmode
LV wall thickness.
Measurement if hypertrophied.
Absence, presence and severity of RWMA.
Mitral Valve : morphology and function.
Mitral Regurgitation
MV annulus. ME LAX
MV abnormal morphology versus functional MR.
Abnormal morphology description (annulus, leaflets, subvalvular apparatus)
Quantification of MR. State Methods used for quantification (2D imaging, colour flow Doppler, spectral Doppler)
Post MV surgery.
Description of type of repair or valve replacement.
Residual regurgitation, & how assessed.
SAM,
Stenosis – accepting that Pt ½ inaccurate post bypass but an indication
Mitral Stenosis.
Anatomy of valve and subvalvular apparatus.
Grading of MS – Pt ½
LA size if enlarged. Measurements specifying views
LAA + /- clot
Aortic Valve
Aortic Stenosis
Quantification by 2D imaging, valve area by continuity equation, pressure gradient
Planimetry alone inaccurate.
Post AV surgery.
Type and size of AV. Pressure gradient. presence or absence of any leaks, with quantification
Aortic Regurgitation.
State quantification method- 2D imaging, spectral Doppler, colour Doppler, Perry index
Masses
Location, shape, size, mobility
.
Endocarditis.
Masses, Complications
Aortic root
Measurements if abnormal anatomy
Thoracic aorta
Presence and classification of atheromas.
Aortic dissection
Site and extent, if possible. State presence of complications: AR, pericardial effusion, LV function, pleural effusion.
Right Ventricle
Function, presence or absence of dilatation.
Tricuspid valve
Quantification of TR and estimation of PAP.
Pulmonary valve
Stenosis or regurgitation.
Presence and position of any additional artefacts such as lines, pacing wires, balloon pump.
Presence of any effusions