FENTANYL

Orotracheal intubation [Ref: Morgan’s Anaesthesia 4/e p. 112; Schwartz surgery 9/e p. 137]

• Patients with severe maxillofacial trauma and with low Sp0₂ even on oxygen suggests severe airway compromise or obstruction.
• In these cases emergency airway management is essential.
• The patient require immediate oxygen.

– These patients needs to be intubated immediately.

– But an important point to note is that severe maxillofacial trauma makes intubation very difficult.

-Some believe that nasotracheal intubation is contraindicated in patients with severe maxillofacial injury because

nasotracheal intubation in these patients can result in nasocranial intubation or severe nasal hemorrhage.

– Nasotracheal intubation is absolutely contraindicated in patients with midfacial injury and C.S.F.

rhinorrhoea.

Orotracheal intubation in patients with severe maxillofacial injury

• In patients with severe maxillofacial injuries orotracheal intubation is also difficult.
• Presence of blood clots, .fractures make the passage of the tube quite difficult.
• Moreover when the surgeons perform operation for mandibular or maxillary fractures they wires both these together.
• If surgery is required with severe maxillofacial injury surgeons usually prefer nasotracheal intubation or tracheostomy.

Tracheostomy in patient with severe maxillofacial injury : ?

• Tracheostomy does not have much role in “emergency airways management”.

– Tracheostomy is a time taking procedure compared to intubation.

– If the airways of the patient is severely compromised and he requires immediate oxygenation, tracheostomy has no role.

– Immediate oxygenation can only be delivered by rapid intubation.

• In case, intubation is impossible, cricothyroidotomy is an alternative.

–In emergency management of the airway, cricothyroidotomy is done if intubation is not possible.

• Tracheostomy is only done when immediate oxygen requirements are taken care of and a surgical procedure is planned.
• In the question the Sp0₂ of the patient is 80% when on oxygen. He requires immediate emergency management of the
  airway which can be achieved through intubation, If intubation is impossible, cricothyroidotomy is an alternative.

The better option of intubation in this patient is orotracheal intubation.

• The ideal management in this patient is cricothyroidotomy.
• Since that is not mentioned in the question intubation in the next best option. 

            “Orotracheal intubation would be preferred over nasotracheal intubation in these cases”

When fentanyl is pushed intravenously very quickly patients chest wall becomes rigid and leads to respiratory failure. This side effect is commonly encountered in neonates although all age groups are susceptible. 

• To provide the analgesic component in general anaesthesia
• In combination with a major tranquilizer to produce neuroleptanalgesia
• To provide analgesia during labour when regional anaesthesia is not in use
• As an agent for patient controlled analgesia
• In premedication
• For palliative care

A i.e. Chest wall rigidity

Nonvolatile Anesthetic Agents: Opioids

• Opiate- receptor activation, inhibits the presynaptic release and post synaptic response to excitatory neurotransmitters (eg. acetyl cholne , substance P) from nociceptive neurons.
• In contrast to other opioid, the time necessary to achieve a 50% decrease in the plasma concentration of remifentanil (its context -/ sensitive half time) is very short (‘- 3 min) and is not influenced by the duration of infusion. The unique easter structure of remifentanil, an ultrashort acting opioid with a terminal elimination half life of <10 min, makes it susceptible to rapid ester hydrolysis by non specific esterases in blood (RBC) & tissue. Biotransformation is so rapid and so complete, that duration of remifentanil infusion has little effect on wake up time. Patient with pseudo cholinesterase deficiency has a normal response to remifentanil.
• Renal dysfunction cause accumulation of normeperidine (end product of meperidine) & morphine 3/6 – glucuronides (end products of morphine). Toxic effects of normeperidine cause excitatory effect on CNS, leading to myoclonic activity & seizure that are not reversed by naloxone.
• Opioids elevated apneic threshold (the highest PaCO₂ at which a patient remains apneic) and decrease hypoxic drive. Morphine & mepiridine can cause histamine induced bronchospasm.
• Opioids (particularly fentanyl, sufentanil and alfentanil) can induce chest wall rigidity, severe enough to prevent adequate ventilationQ. This centrally mediated muscle contraction is most frequent after large drug boluses & effectively treated with neuromuscular blocking agent.
• IV meperidine (25mg) has been found most effective opioid for decreasing shivering.

A i.e. Fentanyl

A i.e. Propofol, Fentanyl, isoflurane

A i.e. Morphine; B i.e. Fentanyl

Spinal Anesthesia is preferred in lower abdominal surgeries as it shrinks the intestines so other viscera can be seen very well.Q

Narcotic (morphine)Q are preferred over LA as motor function is maintained and patient may co-operate in surgery.Q

A i.e. Intra-thecal hyperbaric phenol, B i.e. Antrolateral cordotomy, C i.e. Epidural fentanyl

Management of chronic pain includes patient controlled analgesia (PCA), epidural or intrathecal opioid (fentanyl) & local anesthetic, neurolytic blocks by hypobaric alcohol or hyperbaric phenol, anterolateral cordotomy and various drugs like anticonvulsants, antidepressants, neuroleptics, opioids, serotonergic drugs and az adrenergic agonistQ.