CASE PRESENTATION

1. CASE PRESENTATION Perforating Eye Injury Presenter : Puneet Moderator : Dr. Renu www.anaesthesia.co.inanaesthesia.co.in@gmail.com

2. Age - 8 years • Gender – male • Weight – 25 kg

3. Presenting complaints • Injury to right eye with pen tip • Pain, increased lacrimation, redness and decreased visual acuity in right eye H/o presenting illness • H/o injury to right eye with pen tip 6 hours back • Had two chapaties and glass of milk two hours before the injury

4. Past history • No history of any other systemic illness • No history of allergy to drug • No history of previous anaesthetic exposure or surgery • No history of respiratory tract infection

5. General physical examination • Moderately build, well nourished • No pallor, icterus, clubbing, cyanosis and edema

6. Vitals • Afebrile • Pulse - 84/min regular / normal volume / all peripheral pulses palpable • Respiratory rate – 20/minute

7. Systemic examination • CVS – S1S2 heard, no murmur • Resp – normal vesicular breath sound • CNS- WNL • P/A - soft

8. Airway • Facial profile normal • MMP – I • Mouth opening and neck movements adequate

9. Investigation

10. Premedication

11. EYE EMERGENCIES • Traumatic injuries • Blunt • Penetrating • Chemical burns of eye • Retinal artery occlusion • Most frequent type of eye injury – superficial injury to eye and adnexa • Incidence – young males and children

12. EYE EMERGENCIES (contd…) • Non-traumatic surgical emergencies include • Spontaneous retinal detachment • Infections • Complications of previous surgery

13. Problems identified • Open eye injury • Full stomach • Pediatric patient

14. Open eye injury • Risk of infection • Endopthalmitis • Vitreous loss • Retinal detachment

15. INTRA OCULAR PRESSURE • IOP is determined by • Balance between production and drainage of aqueous humor • Changes in choroidal blood volume • Vitreous volume • Extra ocular muscle tone • Normal IOP 12-20 mm of Hg • Open globe IOP – atmospheric pressure

16. The effect of cardiac and respiratory variables on intraocular pressure (IOP)

17. The effect of anesthetic agents on intraocular pressure (IOP)

18. Strategies to prevent increases in intraocular pressure (IOP) • Avoid direct pressure on the globe • Patch eye with Fox shield • No retrobulbar or peribulbar injections • Careful face mask technique • Avoid increases in central venous pressure • Prevent coughing during induction and intubation • Ensure a deep level of anesthesia and relaxation prior to laryngoscopy • Avoid head-down position • Extubate deeply asleep

19. Strategies to prevent increases in intraocular pressure (IOP) (contd…) • Avoid pharmacological agents that increase IOP • Succinylcholine • Ketamine (?)

20. FULL STOMACH • Ideally all patients should be fasted before undergoing GA • A fast of 6-8 hours for solid food and 2-4 hrs for clear fluids • Most important time interval is that between the last meal and time of injury • Gastric emptying is delayed by pain and anxiety

21. LIFE THREATENING VS SIGHT THREATENING

22. Strategies to prevent aspiration pneumonia • Regional anesthesia with minimal sedation • Premedication • Metaclopramide • Histamine H2-receptor antagonists • Nonparticulate antacids • Evacuation of gastric contents • Nasogastric tube

23. Strategies to prevent aspiration pneumonia • Rapid-sequence induction • Cricoid pressure • A rapid-acting induction agent • Succinylcholine, rocuronium, or rapacuronium • Avoidance of positive pressure ventilation • Intubation as soon as possible • Extubation awake

24. PEDIATRIC PATIENT • Lager occiput  flexed head • Narrow nasal passages • Long epiglottis • Shorter trachea and neck • Tonsil and adenoids • Larynx – anterior and cephalic • Glottis at higher level • Cricoid cartilage is narrowest part • Vocal cords slant anterior

25. PREOPERATIVE EVALUATION AND PREPARATION • Is open globe injury always as surgical emergency • An accurate, through history and physical examination

26. PREMEDICATION Preventing aspiration • Metaclopramide (0.15 mg/kg IV or IM) – facilitates gastric emptying and increases tone of cardiac sphincter, ranitidine 1-1.5 mg/kg IV – reduce risk of aspiration pneumonitis • Sodium citrate can be given 15-30 ml orally prior to induction

27. SEDATION/AMNESIA • Used cautiously and titrated in patients with full stomach • Narcotics and benzodiazepines  ¯ IOP  decreasing anxiety and providing sedation • Diazepam IV prior to induction  ¯ IOP  centrally mediated muscle relaxant properties • Morphine IM  ¯ IOP

28. ANTICHOLINERGICS/ANTI SIALOGOGUES • Used topically  mydriasis  increases IOP • IM or IV no effect on IOP

29. INTRAOPERATIVE • Factors that increase risk of vitreous herniation • Face mask pressing on eye ball • Increased pressure from coughing, bucking and head down position • Extraocular muscle spasm induced by depolarizing muscle relaxants or surgical stimulus during light anaesthesia • Poorly applied cricoid pressure which block venous drainage from eye • Choridal congestion from hypercarbia, hypoxia, intubation or increase in BP

30. INDUCTION • Prior to RSI of anaesthesia – blunt cardiovascular and IOP responses to laryngoscopy and tracheal intubation • Lidocaine 1.5 mg/kg 90 sec before intubation • Labetalol 0.03 mg/kg IV • Induction agents with exception of ketamine provide protective effect on IOP

31. INDUCTION (contd…) • Ketamine • Premedication with diazepam and meperidine before giving ketamine does not effect IOP and that it may even lower IOP in children when given IM • Older studies IOP ­ ketamine • Blepharospasm & Nystagmus and ­ rate of PONV  contradicts it’s use

32. INDUCTION (contd…) • Etomidate • Significantly ¯ IOP within 1 min • Myoclonus • No current evidence that etomidate increases IOP from myoclonus

33. INDUCTION (contd…) • Inhalation agents ¯ IOP • Reduced aqueous humor production • Depression of CNS control centre • Facilitation of aqueous humor outflow • Decreased extraocular muscle tone • Lower arterial BP

34. MUSCLE RELAXATION • Depolarizing muscle relaxant – succinylcholine are mainstay – rapid onset and quick recovery • SCH ­ IOP-10-20 mm of Hg after 6 minutes • Tracheal intubation – further increases IOP but does not prolongs duration • Pretreatment with – B blockers, lidocaine , subparalytic dose of SCH, Benzodiazepines, small does of NDMR to blunt ­ IOP – inconsistent results

35. HOW SUCCINYL CHOLINE INCREASES IOP • ­ Extraocular muscle tension • Choridal vascular dilatation • Contraction of extra ocular smooth muscle • Cycloplegic action – deepening of anterior chamber/increased outflow resistance

36. HOW SUCCINYLCHOLINE INCREASES IOP • NDMR unlike succinylcholine reduce IOP • RSI with Vecuronium 0.2 mg/kg Rocuronium 0.9 – 1.2 mg/kg • Rapid onset 60-90 sec “Although succinylcholine ­ IOP there are no clinical case reports of further eye damage. Loss of vitreous humor or other complications in open eye surgery”

37. Is this an easy airway? Yes No Is the eye viable? Yes No Short-or-intermediate acting nondepolarizing Fiberoptic muscle relaxants laryngoscopy Succinylcholine (after pre-treatments)

38. LARYNGEAL MASK AIRWAY • Does not provide total protection of airway from aspiration • Use limited except in difficult intubation

39. MONITORING • Standard anaesthetic monitoring • NIBP, ECG, Pulse oximetry, capnography • FiO2

40. MAINTENANCE • Adequate level of anesthesia – with volatile inhaled anaesthetics along with NMDR,OPIOIDS,NSAIDS • Maintain normocapnia with controlled ventillation • Avoid hypoxia

41. DURING SURGERY HR 40/MIN • Cause Oculocardiac reflex • Due to traction on medial rectus • In which surgery is it common? • Squint, enucleation, pres. on globe • Contributing factors • Light plane, high vagal tone, hypoxia • Treatment • Stop surgery, remove above factors • Atropine, CPR

42. OCULOCARDIAC REFLEX AFFERENT & EFFERENT PATHWAY? • Afferent • Ciliary ganglion to ophthalmic division of trigeminal N, - through gasserian ganglion to main sensory nucleus in 4th ventricle • Efferent s vagus N

43. Analgesia and control of nausea and vomiting • Nausea and vomiting ­ IOP – can be a major problem • Antiemetic prophylaxis • Ondansetron. 1 mg/kg IV • droperidol 0.01 mg/kg

44. DrugDose • Paracetamol(Acetominophen)Children: 90 mg/kg total per 24 hours orally or rectally in 4-6 divided dosesAdults: 1g orally or rectally. 4g total per 24 hours • Ibuprofen • Children: 10mg/kg orally. 4 doses maximum in 24 hours.Adults: 400 mg orally. 4 doses maximum in 24 hours

45. Diclofenac • Children: 1mg/kg orally or rectally. 3 doses in 24 hours.Adults: 150 mg total by any route in 24 hours • Ketorolac • 0.25-1.0 mg/kg intramuscularly or intravenously. 3-4 doses in 24 hours.

46. EMERGENCE • Empty the stomach with orogastric tube when patient is fully paralyzed Neostigmine with atropine or glycopyrrolate has no effect on IOP • Deeply anaesthetized vs fully awake • Lidocaine spray – loss of gag reflex • Lidocaine 1.5 mg/kg/IV before extubation • Does not always prevent coughing bucking • Sedation effects – delayed awakening

47. A practical approach to emergency eye anaesthesia • Assess the indication for emergency anaesthesia in discussion with the surgeon and if possible allow adequate fasting. • A thorough full preoperative assessment including a history and examination. • Are there any medical/trauma issues that need addressing first? • Decide on choice of anaesthetic technique. Tell the patient what to expect if a local anaesthetic technique is to be used.

48. If a general anaesthesia is chosen and the patient has a full stomach, anti aspiration prophylaxis should be given and a rapid sequence induction technique should be planned. • In case of a child intravenous cannula can be inserted after application of EMLA cream in their parent’s presence and preoxygenated with 100% oxygen avoiding pressure on the affected eye from the mask. The patient is induced with an intravenous anaesthetic agent (eg thiopentone 4-7mg/kg or propofol 2-3mg/kg) and a rapid onset muscle relaxant (suxamethonium 1-1.5mg/kg or rocuronium 0.9 -1.2mg/kg). While the patient is being induced cricoid pressure should be applied by an assistant (Sellick's manouvre) thus occluding the oesophagus behind. Laryngoscopy should be performed gently and trachea is intubated after which the cricoid pressure can be removed. Spraying the vocal cords with lignocaine can minimise the pressor response to intubation. This may also decrease the risk of coughing on intubation. The endotracheal tube tie should not be tight around the neck as this impedes venous drainage and raises IOP. A nasogastric tube should be inserted to decompress stomach.

49. The anaesthesia is maintained with O2, N2O and an inhalational agent. A short acting analgesic should be administered. • Control ventilation should be initiated during the procedure aiming for low to normal end-tidal carbon dioxide with longer acting muscle relaxant along with neuromuscular monitoring. A slight head up tilt helps reduce IOP. • At the end of the procedure, the patient should be extubated on their side and once airway protective reflexes have returned. In patients not deemed at risk of aspiration, extubation with the patient deep and breathing spontaneously may prevent coughing. Intravenous lignocaine 1.5mg/kg or remifentanil 0.5µg/kg 3-5mins before extubation can help in prevention of coughing and straining as this increases the risk of ocular haemorrhage.

50. If the patient does not have a full stomach, general anaesthesia should proceed as for an elective patient. If available laryngeal mask airway insertion will prevent laryngoscopy and intubation i.e. increase in IOP. • Post operatively nausea, vomiting and pain should be kept to a minimum as they can cause rises in intra-ocular pressure. Oral analgesia and an anti-emetic should be administered. Some patients may need stronger analgesia early after surgery i.e. titrated small doses of intravenous opioid (fentanyl, alfentanil, morphine, pethidine) should be given to control pain.