Anaesthesia for high risk patients JPM 2011

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Anaesthesia for the high risk patient

Is een onderdeel van het “Risico management” in anesthesie

J P Mulier MD PhDDiensthoofd Anesthesie AZ sint Jan Brugge-Oostende

Geafilieerd onderzoeker KULeuvenPresident ESPCOP

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risico

• Is een kans op een gekend verlies, complicatie, stoornis– Gemeten naar impact en frequentie

• Is een onzekerheid voor een individu• Is een zekerheid voor een groep

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Identification of the high-risk surgical patient. Non patient factors:• Experience

– Availability of appropriately experienced surgeons and anaesthesiologists

– Hospital case volume– Surgeons case volume

• Timing of surgery– At night higher risks

• Availability of basic equipments• Type of surgery

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Identification of the high-risk surgical patient. Patient factors I• Patient type:

– Gender• Males higher infection, septic shock, mortality, • Females worser after IPPV, vascular surgery

– Age• Very young and very old

– Race • No anesthesia risk factor

– Genetic predisposition• No information yet

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Identification of the high-risk surgical patient. Patient factors

II• Clinical condition

– an unstarved patient with difficult intubation for emergency surgery,

– the emergency caesarean section– fractured neck of femur,– myopathic conditions,– malignant hyperthermia,– hereditary mastocystosis,– latex allergy,– leaking abdominal aortic aneurysm,– Anemia– obesity

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Identification of the high-risk surgical patient. Patient factors III• Medical diseases

– Cardio vascular diseases,• Coronary artery disease or Myocardial ischemia• Hypertension• Valvular heart disease, Congestive heart failure• Arrhythmias and conduction abnormalities• Peripheral vascular disease and cerebrovascular disease

– Pulmonary diseases,• CPOD• Asthma• Smoking• obesity

– Critical ill, multi organ failure– Renal diseases,– Polytrauma,

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Identification of the high-risk surgical patient. Surgery related factors

• Anatomical site of surgery• Duration of surgery

– Cardiac bypass time – Pneumoperitoneum time– One lung ventilation time– Total blood loss

• General anaesthesia and muscle relaxants

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Peri operative deaths

• National Confidential Enquiry into Perioperative Deaths (NCEPOD)– Mortality 30 days post operative

• Emergency surgery 1,4 %• Elective surgery 0,5 %• Patients > 70 years: 70 %• Coexisting med disease: 94 %• Death within 5 days post op: 50 %

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The elderly patient• Complication rates and morbidity following anesthesia are increased in

the elderly [27]. • the occurrence of complications increases hospital stay.• Deaths today: Patients are more likely to be older, have undergone an

urgent operation, be of poorer physical status and have co-existing cardiovascular or neurological disorder”.

• The 1999 UK CEPOD report [20] that looked specifically at patients over 90 years at the time of operation recognized that “elderly patients have a high incidence of coexisting disorders and a high risk of early postoperative death”.*

• The occurrence of postoperative complications, especially respiratory and renal compli- cations, are independent predictors of reduced survival [29] and must be vigorously prevented and treated.

• intraoperative tachycardia as a predictor of cardiac complications

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The morbid obese patient

• Zie afzonderlijke lezing

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The critical ill patient• The anesthetist may influence overall outcome of the critically ill patient

in the OR by several mechanisms, some more controversial than others.*Choice of anesthetic agents. Poor hemodynamic control [71] or poor fluid balance – both of which may

influence the development of ischemia or organ failure.*Ischemia. Volatile agents (and probably opiates) seem to protect the heart

from subse- quent ischemia (preconditioning) similar to the preconditioning due to previous ische- mia.

volatile anesthetics, when compared to intravenous anesthetics, seem to result in better cardiac function, lower troponin concentrations, less requirement for inotropic support, reduced duration of mechanical ventilation, and reduced hospital length of stay.

Deep anesthesia (as reflected by a bispectral index score <45) has been shown in a prospective observational study of adult patients undergoing major noncardiac .

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Timing of operation: Perioperative maintenance of normothermia reduces the

incidence of morbid cardiacpatients without acute lung injury?

Respiratory muscle contribution to lactic acidosis in low cardiac output.

Positive end-expiratory pressure prevents atelectasis during general anaesthesia even in the presence of a high inspired oxygen concentration.

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The cardiac patient: tests to stratify risk I• 12 lead ECG

– One risk factor and vascular op– Diabetus – Previous coronary revascularisation– Men > 45 women > 55– Previous cardio vasc disease

• 24 h ECG holter– Not for high risk other reasons

• Echocardio/angiography– Dyspnoe of unknown origin– History of CHF

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The cardiac patient: tests to stratify risk II

• Stress testing– Exercise, dobut, radionuklide, echocardio

• Invasive testing– Angiography not for non clinical symptoms

• Pre op revascularisation with CABG or PCI– not for non clinical symptoms

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Peri operative MI

• The diagnosis is made more diffficult as only– 14% of patients have chest pain – 53% have any sign or symptom at all

• The ECG and biomarkers of cardiac damage (troponins) play an important role, along- side a high index of suspicion.

• Perioperative MI – increased in-hospital stay – longer-term mortality.

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Beta-blockade peri-operativeseloken propanolol atenolol labetolol• Patient on beta-blocker, continue • Ischemia on preoperative testing or multiple risk factors

for cardiac ischemia, consider starting a beta-blocker • Only the highest-risk patients receive most benefit• Longer half-life beta-blockers provides more benefit• Heart rate control appears to be the most beneficial effect

of beta-blockade in the perioperative setting• Benefit appears to be dose-related, give highest possible.• Chronical beta-blockers should not be stopped abruptly

because of the beta-blocker withdrawal syndrome

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Renin–angiotensin blockade: angiotensin converting enzyme inhibitors (ACE) and angiotensin receptor blocking agents (ARB)

captopril enalapril

• Exposure to ACE inhibitors and ARB agents is associated with hypotension following the induction of anesthesia.

• ACE inhibitor and ARB exposure is an independent risk factor for death within 30 days of surgery in vascular surgery patients

• Not giving one dosing interval is associated with a reduction in the frequency of hypotension following the induction of anesthesia.

• The benefits of long-term therapy will persist if the medication is held for the immediate perioperative period and then restarted shortly after surgery.

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Calcium channel blockers: CaCBverapamil diltiazem

• CaCB interact with inhaled anesthetic agents and neuromuscular blocking agents used in anesthesia.

• Patients chronically treated with CaCB show decreases in SVR and mean arterial pressure.

• No harm has been reported in large studies of perioperative use of CaCB.

• Meta-analysis has shown some benefit towards reduction of ischemia, arrhythmias,myocardial infarction but not mortality.

• The expected benefits are small due to the large numbers of patients that need to betreated to show effects.

• It seems reasonable to continue patients chronically taking CaCBs, but not to start therapy just prior to surgery.

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HMG CoA reductase inhibitors: statinszocor lipitor crestor

• For patients chronically taking statins, the statins should be continued in patients scheduled for noncardiac surgery

• There has only been one randomized study to show a risk reduction with the starting of statins perioperatively

• The discontinuation of statins perioperatively is associated with an increase in risk of cardiac events

• Statin use is reasonable in patients undergoing vascular surgery • Patients with at least one risk factor undergoing intermediate or major

surgery should be considered for starting a statin preoperatively• Preoperative statin therapy has also been associated with decreased

mortality following coronary artery bypass grafting• Statins should be restarted as soon as possible following surgery

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Nitrates

• Patients should use nitrates as needed but should otherwise minimize use.

• In many centers, nitroglycerin patches are discontinued prior to the induction of anesthesia and surgery.

• There is no conclusive information available to help the perioperative physician know what to further advise patients.

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Scoring systems and risk indices

• American Society of Anesthesiologists (ASA) status– Important points not taken into account are:

• age – some add an extra grade for ages >75,• complexity of operation, • duration of operation, • whether the disease process is associated to the

current illness

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Revised Goldman Cardiac Risk Index• Six independent predictors.

• High-risk type of surgery • History of IHD (previous MI or a positive exercise test,

current complaint of chest pain considered to be cardiac in origin, use of nitrate therapy, or ECG with pathological Q waves.

• History of CHF. • History of cerebrovascular disease. • Diabetes mellitus requiring treatment with insulin. • Preoperative serum creatinine >2.0 mg dl−1

– no risk factors = 0.4% for major cardiac complications– one risk factor = 1.1% “– two risk factors = 4.6 “– three risk factors = 9.7% “

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Pulmonary complications

• •pneumonia,•respiratory failure requiring mechanical ventilation,•bronchospasm,•atelectasis,•exacerbation of chronic underlying disease

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Preventie door

• Veilig werken– Opgeleid personeel– Veilige en gecontroleerde toestellen– Veilige werkwijze

• Leer door ervaring:– Noteer uw ongevallen en bijna ongevallen (FONA)

• Ken uw risico patienten– Wat bepaalt een risico ?

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Tandletsels

Onvoldoende mondopening, moeilijke intubatie, alleenstaande tanden bovenkaak

Tandcaries tandbreukPeridontitis tand uitvalRisico niet alleen tijdens intubatie

Ook mayo canule, echo sonde, OTT tijdens wakker worden wanneer patient bijt !

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Neuropathie

N ulnaris neuropathie bij:Elleboog flexie over 100°Voorarm pronatieLocale druk voorarmHypotensie locaal of algeheelobese mannen, asymptomatische maar abnormale ulnaris pre op

symptomen pas 48 uur na operatie, ook niet geopereerde patienten even frequent ulnaris neuropathie

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Conclusie: AanpakKen de risico’s vooraf

Communiceer deze naar patient en chirurgOnderzoek de ernst van het risicoEffect van vroegere anesthesieVoldoende monitoring per opKies een oppervlakkige of juist zeer diepe

anesthesieOpname op intensieve post opStel uit indien patient in betere toestand gebracht

kan wordenZorg voor aandacht en kwaliteit verbetering