Week 10/12

anaesthesia

absence or abolition of sensation

types of anaesthesia

general, spinal, epidural, topical

general anesthesia

Required for majority of surgical procedures, including abdominal, cardiothoracic, head and neck and vascular surgery

stages of general anesthesia

induction, maintenance, emergence

epidural

injected anesthesia into subarachnoid space in spinal cord, often in lower back

common use of topical anesthesia

kids before IVs

analgesia

the absence or abolition of pain

routes of analgesia

epidural, oral, intramuscular, peripheral block, IV

common use of epidural analgesia

lower abdominal surgery

common uses of peripheral block analgesia

thoracic, upper abdominal surgery

types of IV analgesia

patient controlled or continuous (nurse controlled)

effects of anaesthesia and surgery

pulmonary dysfunction, cardiovascular instability, deep vein thrombosis,

pulmonary dysfunction from anesthetic

pain and abdominal muscle splinting, respiratory depression, impaired cough, sleep, incision, diaphragmatic dysfunction

pain and abdominal muscle splinting

hypoventilation and immobility

respiratory depression

• Lingering effects of anaesthesia or narcotic analgesics

• Strong effect on the brainstem = decrease respiratory centre drive to breathe

impaired cough

• Incision pain - can't cough at all

• Decreased lung volume and expiratory flow rates - inefficient cough

• Analgesics depress cough reflex - opioids, morphine

sleep

may cause abnormal chest wall function

diaphragmatic dysfunction

• Incision of diaphragm

  • Deliberate of accidental

• Distension

  • Distended abdomen = pushes diaphragm superiorly

  • Compresses the bottom of the lungs

• Position

  • Flat on their back = diaphragm moves up

cardiovascular instability after anesthesia

decreased cardiac output and blood pressure

causes of decreased cardiac output and blood pressure

blood volume deficit, myocardial depression, abnormal rates and rhythms, effects of epidural anesthesia

blood volume deficits

• Inadequate management of blood volume intra-op

• Rapid bleeding

• Need to determine if this is a big enough effect to not mobilise them

myocardial depression

drugs = decrease contractility and cardiac output

abnormal rates and rhythms

• Worse if myocardium has been cut into - valve repair or replacement

• Changes in electrolyte balance = changes in action potential = abnormal contraction

  • Hypo- or hyper-volumaemia

risk factors of deep vein thrombosis

• Age, obesity, immobility >4 days, varicose veins, pregnancy, post-partum, high dose oestrogen therapy, smoking history, malignancy, previous DVT/PE

• Fracture/major ortho surgery of pelvis, hip or LL

• Pelvic or abdominal surgery for cancer

identification of deep vein thrombosis

identify hgih risk group, eary ambulation and avoid leg crossing, cinical diagnosis, official diagnosis

clinical diagnosis of DVT

fever, temp of limb, pain, swelling

diagnosis of DVT

venogram, doppler ultrasound

other effects of analgesia

fluid imbalance, wound problems, hypothermia, neurological changes, haemorrhage, nausea and vomiting, shivering, amnesia, fatigue, hiccups

post operative pulmonary complications

atelectasis, hypoxaemia, chest infections, pulmonary embolism

clinically significant PPCs

alter the patient’s clinical course following surgery

• length of stay

• need extra medication

• requires more treatment

signs and symptoms of PPCs

arterial oxygen desaturation, radiological evidence of atelectasis or pneumonia, raised oral temp, yellow/green sputum, bacterial growth on sputum microbiology, raised WCC, prescription of antibiotics, abnormal lung uscultation

risk factors of developing a PPC

anaesthesia >180 minutes, incision site above umbilicus, pre-existing respiratory and cardiac disease, smoking, reduced level of preoperative activity, severe malnutrition, nasogastric tube for >5 days, age >60

additional risk factors of PPCs for thoracic surgery

anemia, obesity, excessive lcohol intake

non-risk factors of PPCs

obesity, mild/moderate asthma, lower abdominal surgery

average length of atelectasis after surgery

2 days

causes of post-surgery atelectasis

induction of anesthesia, pain, prolonged recumbency, drowsiness and immobility, diaphragm dysfunction, absorption atelectasis, respiratory depression

relationship between functional residual capacity and closing capacity in atelectasis

CC exceeds FRC

closing capacity

the volume in the lungs at which point the smallest airways begin to collapse

pathology of post-surgery hypoxaemia

localised atelectatic alveoli causes decreased ventilation which decreases v/q mismatch

causes of post-surgery hypoxaemia

depression of respiratory centre, inhalation of dry gases, atropine, irritation by the endotracheal tube

atropine

commonly used medication in cardiac surgery to maintain heartbeat, causes dry secretions

causes of post-surgical chest infection

• Intubation overrides defence mechanisms

• Anaesthetic agents impair ciliary action

• Cough reflex diminished

• Hospitalisation

• Persistent atelectasis may be associated

physiotherapy problems in patients following surgery

reduced lung volume, impaired gas exchange, impaired airway clearance

pathophysiology of reduced lung volume after surgery

• Atelectasis

• Compression/contraction of lung tissue

• Decreased compliance

• Fibrosis

• Abnormal posture

• Pain

evidence of reduced lung volume after surgery

• Reduced chest expansion

• Abnormal

  • Auscultation

    • Diminished breath sounds, usually in the bases

    • Bronchial breathing

  • CXR

  • SpO2

  • ABGs

• Weak cough

prevention and treatment of post-operative atelectasis

ensure adequate pain relief, increase FRC and VT

management of impaired gas exchange in patient following surgery

treat atelectasis with positioning, ambulation, SMIs, CPAP

monitoring during intervention

subjective report of symptoms, observation, SpO2, manual pulse palpation

short term outcome measures

auscultation, chest expansion, oxygenation (SpO2), cough, mobility

medium term outcome measures

CXR, LOS, prevent clinically significant PPCs