Medical Problems In The Surgical Patient

Dr Osama BawazirFRCSI, FRCS(Ed), FRCS (glas),

FRCSC.

IntroductionIntroduction

• “A chance to cut is a chance to cure”

• “Nothing heals like cold, hard steel”

• Surgery = stress and insults– Physiology of surgery– Maximize pre-operative condition of patient– Preoperative evaluation: H&P– Perioperative care: think of what can kill

first...

Perioperative medical care:Perioperative medical care:

• Surgical emergency• Cardiac disease• Pulmonary disease• Renal dysfunction• Liver dysfunction• Diabetics• Bleeding disorders• Malnourished

Perioperative medical care:Perioperative medical care:• Surgical emergency• Cardiac disease• Pulmonary disease• Renal dysfunction• Liver dysfunction• Diabetics• Bleeding disorders• Malnourished

Pulmonary diseasePulmonary disease

• Patient-related risks– Chronic lung dz –

wheeze, productive cough

– Smoking– General health– Obesity– Age?

• separate from others?

• Procedure related risks– Type of anesthesia

• GETA alone FRC 11%• inhibited coughing peri-

op

– Surgical site– Duration of surgery

Modifiable pulmonary risksModifiable pulmonary risks

• Obesity physiology lung capacity, FRC, VC WOB– hypoxemia

• Tobacco– Definition of “stopped

smoking”....– “When was your last

cigarette?”

Pre-operative risk assessment: Pre-operative risk assessment: pulmonary functionpulmonary function

• Patient history– unexplained dyspnea, cough, reduced exercise tolerance,

OSA

• Physical exam:– wheeze, rales, rhonchi, exp time, BS– 5.8x more likely to develop pulmonary complications*

• Pre-operative CXR is mandatory over 40 yo• ABG

– no role for routine use– result should not prohibit surgery

• caution if PaCO2

* Lawrence et al Chest 110:744, 1996

Respiratory problems Respiratory problems

• second only to cardiovascular events as a cause of perioperative death.

• Several risk factors ↑pulmonary complications, including• age• male gender• emergency surgery• ASA status• length of the surgery.

• The main two specific factors pre-existing respiratory disease surgery of the chest or upper abdomen.

• Clinically: • Atelectasis• bronchospasm• retained secretions• infectious complications

EFFECT OF SURGERY AND ANAESTHESIA ON EFFECT OF SURGERY AND ANAESTHESIA ON RESPIRATORY FUNCTIONRESPIRATORY FUNCTION

• Ventilation– Opioids can produce profound

respiratory depression. – The inhalational anaesthetics halothane,

enflurane, and isoflurane also depress respiratory drive.

• Lung volumes– functional residual capacity is reduced

during general anaesthesia by about 20 per cent below the value measured in the awake, supine position.

– the diaphragm ascended into the chest by about 2 cm during anaesthesia with or without paralysis

• Gas exchange– V/ Q mismatch – Elimination of CO (changes in the ratio

of dead space to tidal volume )

• Host defences• dryness tends to damage the respiratory

epithelium. • The cough mechanism is depressed during

anaesthesia • the immune system is altered in the immediate

postoperative period

1.The alveolar/arterial Po2 gradient is increased during anaesthesia, and this change is markedly affected by age.

2.The decrease in Po2 is secondary to an increased distribution of flow to areas of decreased ventilation, most commonly the dependent areas.

3.The increase in VD/ VT seems to be secondary to increased distribution of ventilation to areas of lesser perfusion.

4.The major differences are between the awake and anaesthetized state; paralysis and controlled ventilation do not greatly alter overall gas exchange.

Management Management Estimate function:

Clinical and Specialist opinion. ABG CXR Spirometry: FEV1/FVC, PEFR

Chest infection: Postpone for 2 weeks Antibiotics & Physio.

COPD Leis with specialist Reschedule surgery.

Plan to transfer to ICU for mechanical ventilation pending:Lung function, type & duration of surgery.

Optimization of pulmonary function Chest physical therapy Pharmacological therapy NON-INVASIVE RESPIRATORY MONITORING ANAESTHETIC TECHNIQUE

SmokingSmoking 10 cigr.=6 fold increase in post-op

respiratory complications. Respiratory and CVS effects Carbon monoxide has higher affinity

for O2 than Hb. Nicotine increases heart rate and BP. Hypersecretion of thick mucus Immunosuppressive Stop 3 months= improve pulmonary

functions Stop 1-2 days= Decreases CO levels.

““Surgeons as medical doctors”Surgeons as medical doctors”

Smoking cessationSmoking cessation

• 83% of patients think MD’s are against smoking– 55% think THEIR DOCTOR is against it

• 55% say their MD has never advised to quit smoking– despite that 22% say MD inquired of smoking hx

• MD can make a difference– 81% have tried to quit if MD says to– 61% have tried to quit if MD says nothing

• Pts less likely to try to quit if advised to “cut down”* Mullins and Borland, Aust Fam Physician 22(7):1146, 1993.

AgeAge•Distinction must be made between physiological state and chronological age.•Are less mobile, intercurrent disease, less physiological reserve.•Caution with regards to:

•IVF & Narcotic analgesia.•More likely to have wound infection.•In 65 CVA 1%, In 80 CVA 3%

ObesityObesity

BMI> 30 Increased risk in:

DVT, Wound infections & Dehiscence Respiratory complications & sleep

apnoea. Intercurrent diseases. Operative difficulty

Relative risk of mortality 3-5 Advise controlled wt reduction Arrange ICU post-op

Cardiovascular DiseasesCardiovascular Diseases

PredictorsMajor: Unstable coronary syndrome. Decompensated CCF. Significant Arrhythmias Severe valvular diseaseIntermediate: Mild angina PMH MI Compensated CCF DMMinorAge, abnormal ECG..etc

CARDIOVASCULAR DISEASESCARDIOVASCULAR DISEASES

• Recent infarction• EF< 40%• left ventricular failure • Persistence of angina after infarction

• Angina

• Silent ischaemia

• Coronary artery bypass grafts

Chest Pain Work UpChest Pain Work Up

• History of event• Physical exam• 12-Lead ECG• CXR• ABG• Cardiac Panel• BMP, M/P, CBC, PT, PTT, INR• Chart Review

TachycardiaTachycardia• Delivery O2=1.34 hgb X O2 sat X SV X HR• Hypovolemia (Think Bleeding)• Anemia• Hypoxemia• MI• Arrhythmia• PE• Pain• anxiety

Cardiac disease in peri-op periodCardiac disease in peri-op period

• CAD can cause any of these

• Risks for CAD:– age, sex, HTN, XOL, DM, tobacco

• Modify those risk factors you can...

MIMI arrhythmiasarrhythmias CHFCHF

XX

will cover later. . .medical therapy

Coronary Artery DiseaseCoronary Artery Disease• Definition of CAD....

• Physiology of surgery: myocardial oxygen demand catecholamines: HR, contractility, PVR HR also causes decreased diastolic filling

• Coronary arteries fill in diastole• Less blood flowing in coronaries: less myocardial O2 supply

Myocardial InfarctionMyocardial Infarction• Pt without risks has 0.5% chance of MI

– Pt with risks has 5% chance of perioperative MI

• Perioperative MI has 17-41% mortality• CAD causes MI....look at PMH• Risk stratifications:

MI w/in 3 months of OR 27% reinfarction rate

MI 3-6 months before OR

10% reinfarction rate

MI >6 months of OR 5-8% reinfarction rate*

Myocardial infarctionMyocardial infarction• O2 supply / demand imbalance: ANGINA

– Surgical stress increases demand

• Treatment – “MONAB”– Morphine– Oxygen– Nitroglycerin– Aspirin– Beta-blockers

• Cardiac panel (troponin, CK-MB), ?Heparin

Prevention of perioperative Prevention of perioperative cardiac eventscardiac events

1) Wait 6 months if possible2) Beta-blockade*

• 200 pts with CAD or risk factors for CAD• atenolol pre-op and peri-op in ½ • MI reduced 50% in first 48h• 2 year mortality 10% vs 21%

3) Maintain peri-operative normothermia cardiac events, esp. arrhythmias

4) Treat peri-operative hypertension

* Mangano NEJM 335:1713, 1996.

Prevention of perioperative Prevention of perioperative cardiac eventscardiac events

5) Invasive monitoring (Swan Ganz) – no help

6) Pre-op CABG (CARP trial) – no difference

American College of Cardiology / AHA now recommends CABG in preop pts who ordinarily meet CABG criteria:

1. L main dz2. 3V dz with LV dysfxn3. severe prox LAD stenosis4. MI despite maximal medical Rx

Prevention of perioperative Prevention of perioperative cardiac eventscardiac events

7) Watch for and treat arrhythmias

Causes?

Treatment?

Drugs, electrolytes, ischemia, fluid shifts, body T

underlying cause, rate control, conversion

• Arterial hypertension• Heart failure• Valvular disease• Cardiomyopathies• Cerebrovascular

disease• Peripheral vascular

disease• Dysrhythmias and

heart blocks

Action: Evaluation:

Clinical, Specialist opinion, ECG, Stress ECG, CXR, Echo..others(Holter monitoring, Exercise electrocardiography, Nuclear imaging, Cardiac catheterization)

IF Major: Cancel unless life threatening Consider CABG prior to elective surgery.

If intermediate: Objective performance.

Hypertension: Indicates CAD More likely to develop hypotension during surgery. Control prior to surgery.

Perioperative medical care:Perioperative medical care:

• Surgical emergency• Cardiac disease• Pulmonary disease• Renal dysfunction• Liver dysfunction• Diabetics• Bleeding disorders• Malnourished

Patients with special Patients with special preoperative needspreoperative needs

• 37 yo WM with longstanding type I DM and with ESRD for 20 years, HD dependent, severe retinopathy, and s/p multiple LE amputations for non-healing diabetic ulcers.

• Admitted for Abx for wound infection• Evening RN calls you for “nausea and sweating”

Patients with diabetesPatients with diabetes

• Possible occult CAD (diabetic neuropathy)– Look for “anginal equivalents”

• SOB• Nausea

– “All patients with longstanding DM have CAD”

• EKG, cardiac enzymes

Patients with diabetesPatients with diabetes

• Hyperglycemia facilitates infection– Warm medium with food for bacteria

• Treat suspected infection aggressively

• Tight glucose control is one of 2 therapies that has been shown to improve outcome of septic patients in the ICU– What is the other?

DiabetesDiabetes

Patients are more sensitive to protein depletion, U&E& glucose imbalance.

Surgical stress can precipitate DKA. DKA is a cause of acute abdomen Decreased phagocytosis, neutrophil

activation and antibody production Small vessel disease Peripheral vascular disease Peripheral neuropathy Autonomic neuropathy Recognition of hypo/Hyperglycaemic attacks

ManagementManagement

Minor LA NSC

Type II GA 4 hourly close observationsOmit dose in mane.Either low dose infusion or fixed dose insulin

Type I GA GIKG: 500 ml 10% dextrose I : Insulin sliding scaleK : Potassium 10 mmolContinue till first light meal

Specialist Opinion required

Renal:Renal:

Identify the cause: Pre-renal, eg: cardiac,

hypovolaemia Renal, eg: acute tubular necrosis(

drug induces) Post renal, eg: obstructive

uropathy.

Identify pt for renal dialysis.

Check K levels

Accurate fluid balance Look for signs of fluid overload. Do not misinterpret poly ureamic

phase

Perioperative medical care:Perioperative medical care:

• Surgical emergency• Cardiac disease• Pulmonary disease• Renal dysfunction

– Dialysis dependent

• Liver dysfunction• Diabetics• Bleeding disorders• Malnourished

Renal dysfunctionRenal dysfunction

• Not all renal failure is oliguric• H&P• Check BUN/Cr• Assume DM have CRI

– Volume status– Electrolytes.....sequelae?

• Which ones?

• Drug metabolism

Renal dysfunctionRenal dysfunction

• Dialyze preop to improve electrolytes, volume status

• No K+ in MIVF• Very judicious MIVF

while NPO• Altered drug

metabolism• Altered platelet fxn

Post op care In renal failurePost op care In renal failure

• Fluid and electrolyte balance

• Anaemia and bleeding

• Drug prescription

ACUTE RENAL FAILURE ACUTE RENAL FAILURE

MANAGEMENTMANAGEMENT

• Diagnosis• Exclusion of obstruction• Recognition and

correction of prerenal failure

• Recognition of pre-existing chronic renal failure

• Immediate management and indications for urgent dialysis

• Prophylaxis and attempts at reversal

haematological Disordershaematological Disorders

• Liver disease• Chronic renal failure• Vitamin K deficiency• Anticoagulants• Massive blood

transfusion• Cardiopulmonary

bypass • CONGENITAL

DISORDERS OF COAGULATION e.g Haemophilia

haematological Disordershaematological Disorders

Anaemia Correction 1 week pre-op Correction day preop is undesirable Haemodilution

Thrombocytopaenia In splenomealy, Platelets must be transfused immediately

preop and on ligating the arterial supply.

Sickle cell disease Crisis caused by : dehydration, infection, hypoxia,

hypothermia. Jaundice & anaemia Splenic infarctions: sepsis Prevention: Warm, well hydrated, well analogised Consider exchange transfusion in SS

Correction of coagulopaties

• THROMBOPHILIA• HAEMOGLOBINOPATHIES

• Sickle-cell disease• Sickle-cell trait• Thalassaemia

• MYELOPROLIFERATIVE DISORDERS• LYMPHOPROLIFERATIVE DISORDERS• AUTOIMMUNE DISORDERS e.g

Idiopathic thrombocytopenic purpura

Hepatic problemsHepatic problems

Hepatic dysfunctionHepatic dysfunction

• Postoperative hepatic dysfunction in surgical patients can be due to (1) overproduction of

bilirubin (2) hepatocellular

dysfunction (3) extrahepatic biliary

obstruction

THE SURGICAL PATIENT WITH THE SURGICAL PATIENT WITH PRE-EXISTING LIVER DISEASEPRE-EXISTING LIVER DISEASE

• Improvement of the preoperative status of patients with liver disease can significantly decrease their operative morbidity and mortality. Specific attention should be given to:

(1)correction of coagulopathy to normal by administering vitamin K and fresh frozen plasma;

(2)improving the nutritional status;

(3)treatment of renal impairment;

(4)treatment of infection;(5)control of ascites.

• Patients with obstructive jaundice are at risk of postoperative renal failure, haemorrhage, and deterioration in liver function.

Jaundice poses a risk for: Sepsis Clotting disorders Renal failure Liver failure Fluid and electrolyte

abnormalities Drug metabolismManagement: Vit k & FFP Adequate hydration and

diuretics & oral Lactulose Antibiotics Nutrition.

Perioperative medical care:Perioperative medical care:

• Surgical emergency• Cardiac disease• Pulmonary disease• Renal dysfunction• Liver dysfunction• Diabetics• Anticoagulated

• Malnourished

AMPLE history

Wait 6 months, Beta block, MONAB

Risk stratify (patient, family, surgery team)

Monitor e’lytes, volume closely

Correct coagulopathy; risk stratify

Glucose control, anginal equivalents

Reverse anticoagulation if tolerated

Anticipate and plan

Feed enterally

(SUMMARY)(SUMMARY)

Question?Question?

Thank You