Anesthesia and addicted patient

1. Anesthesia and addicted patient ד"ר איזבלה פילצ'ה מומחית להרדמה

2. Anesthesia Goals Unconsciousness Amnesia Analgesia Lack of movement Stable autonomic reflexes Uneventful recovery

3. - Unconsciousness – barbiturates, propofol, etomidate, ketamine, inhalational anesthetics, benzodiazepines - Amnesia – benzodiazepins, barbiturates, butyrophenons (droperidol) - Analgesia– opiates, nerve blocks, regional anesthesia

4. - Immobility – neuromuscular blockers,nerve blocks, regional anesthesia - Attenuation of autonomic responses – sympatolytics (e.g., Beta-blockers)

6. Addicted patient O2 Hyperactive airway – increased incidence of cough, bronchspasm, laryngospasm A higher risk of pulmonary aspiration because of a delay in gastric emptying (in opioid users) or depressed consciousness. Difficult airway

7. Anesthesia Goals Regional anesthesia • Unconsciousness/ Sedation • Amnesia +/- • Analgesia • Lack of movement • Stable autonomic reflexes • Uneventful recovery

8. Epidural analgesia and peripheral nerve blocks

9. Contraindications to regional anesthesia Patient refusal Local infection Abnormalities of coagulation Sepsis Hypovolemic shock CNS tumor

10. Injected drugs and high-risk sexual behaviors are key risk factors for the transmission of blood-borne diseases. HIV infection is not considerated as contraindication to regional anesthesia.

11. BUT: HIV crosses the blood-brain barrier and enters the nervous system early, probably concomitant with initial systemic infection. HIV-infected patients are at risk for a wide range of neurologic diseases.

12. Vertebral osteomyelitis is most commonly caused by bacterial pathogens after hematogenous spread. Infection from bone can extend into the epidural or subdural space forming an abscess, which may lead to spinal-cord compression and neurological deficits.

13. Patients under regional anesthesia may also show combative behavior and altered pain perception

14. Difficult venous access • After years of intravenous drug use, superficial and peripheral veins may become obliterated so that proximal and more central veins are used for drug injection. • Besides mechanical and toxic complications (pneumothorax, intraarterial drug injection), the use of large proximal veins may result in life-threatening septic deep vein thrombosis.

15. Ultrasonography-Guided Peripheral Intravenous Access

16. Perioperative treatment strategies for the management of drug addicts Anasthesiol Intensivmed Notfallmed Schmerzther. 2010 May;45(5):304-13.

17. Stabilization of the physical dependence by substitution therapies Avoidance of distress or craving Perioperative stress relief

18. Strict avoidance of inadequate analgesic treatment Postoperative optimization with regional or systemic analgesia with non-opioids, opiods and co-analgesics Consideration of specific physical or psychological comorbidities.

19. Inadequate analgesic treatment is known to be responsible for relapses into addiction and has strictly to be avoided.

20. Physical comorbidities Adequate analgesic treatment

21. Usual preoperative evaluation Airway assessment History of allergies, smoking Concurrent disease & treatment Previous operations ECG: men > 40 years, women > 50 years Hemoglobin: women in childbearing age Other tests and labs – according to concurrent disease, treatment & history

22. Implications of specific substances on anesthesia management • Cocaine

23. Vasoconstriction vasospasm end organ damage: stroke, myocardial depression /infarction, LVH, contraction-band necrosis, acute aortic dissection, blindness, renal infarction, limb ischemia, and intestinal ischemia.

24. Cocaine A major concern is the appearance of cardiac arrhythmias, such as ventricular tachycardia, frequent premature ventricular beats or torsades de pointes. Beta-blockers should be used with great caution because unopposed alpha-adrenergic effect.

25. Infection or perforation of the nasal septum may have implication for nasal intubation, naso-gastric tube placement. Cocaine induced thrombocytopenia may preclude administration of epidural/spinal anesthesia.

26. Pulmonary complications associated with cocaine range from simple asthma to pulmonary hemorrhage.

27. Obstetric complications in cocaine users Pregnancy enhances cardio-vascular sensitivity to cocaine. In pregnancy cocaine use may mimic eclampsia/pre-eclampsia. Spontaneous abortion is more frequent in cocaine users in early pregnancy, and premature labour is also common.

28. Placental abruption occurs in 10% of regular cocaine users, and cocaine accounts for 10% of foetal deaths in the United States of America.

29. Butyrylcholinesterase deficiency The incidence of acute cocaine poisoning was shown to be higher in the patients with low blood butyrylcholinesterase (BChE) level.

30. This enzyme also metabolizes succinylcholine. • Clinical expression of butyrylcholinesterase deficiency is a prolonged apnea after use of this short-acting myorelaxant . • Till 30% of population are heterozygote for BChE mutation. • The atypical butyrylcholinesterase variant has a particularly high frequency in Israelis.

31. Hyperthermia Callaway CW, Clark RF. Hyperthermia in psychostimulant overdose.  Ann Emerg Med. Jul 1994;24(1):68-76 Because dopamine plays a role in the regulation of core body temperature, increased dopaminergic neurotransmission may contribute to psychostimulant-induced hyperthermia in cocaine users, including those with excited delirium.

32. Excitement, delirium, and hyperthermia frequently precede the onset of cocaine-associated rhabdomyolysis.

33. Case report K M Kuczkowski Arch Gynecol Obstet (2009) 280:1059–1061 • A 28-year-old, otherwise healthy woman developed sudden episode of substernalchest pain, hypertension, transientventriculardysrhythmiasarrhythmias, and convulsions with progressive desaturation in the postpartum period 2 h following an uneventful normal spontaneous vaginal delivery at term (under uneventful epidural labor analgesia).

34. The patient had no known drug allergies, no documented history of substance abuse, and no other signifcant medical history.

35. With the working diagnosis of eclampsia the seizures were treated with the rapid sequence induction of general anesthesia with intravenous dosages of diazepam,, thiopental, and with continuous pressure applied to the cricoid cartilage, followed by endotracheal intubation.

36. To prevent further episodes of seizures (given the working diagnosis of eclampsia) intravenous magnesium sulfate was administered. No subsequent adverse events were reported and the patient was extubated after a 15–20 min period of assisted ventilation with oxygen 100%.

37. The diagnosis of eclampsia was ruled out by routine laboratory studies (liver and kidney function tests). The toxicology screening tests were ordered. Indeed, toxicology screening was positive for amphetamines, and patient admitted to recent (1 h prior to labor) drug intake rehabilitation.

38. Postpartum convulsions and acute hemodynamic instability in the parturient with recent amphetamine intake Case report

39. Marijuana Although acute toxicity or major anesthesia interactions from this drug are rare, every system is affected by its use and its clinical picture is unpredictable.

40. Cannabis inhalation affects lung function. There have been reports of oropharyngitis, acute upper-airway edema and obstruction in cannabis-smoking patients who have undergone general anesthesia. Some even recommend administering dexamethasone as prophylaxis to these patients if undergoing general anesthesia.

42. The chronic intake of opioids Philippe Richebe Can J Anesth 2009 56:969-981 Perioperative pain management in the patient treated with opioids The chronic intake of opioids has an impact on postoperative pain management. Thus, according to two studies, patients already taking opioids required three to four times as much opioids in the postoperative period than patients not taking opioids before surgery.

43. The consequences of chronic opioid consumption • Tolerance • Dependence • Hypersensitivity: • allodynia, • hyperalgesia

44. Perioperative management Miller’s Anesthesia 7th edition Chapter 34, pp.1042 Patients on Methadone maintenance regimens continue the drug through the day of surgery. Because it may be difficult to overcome the analgesic agonist effect of Suboxone, it should be stopped 3 days before surgery.

45. Patients may require substitution to avoid relapse of addiction during this period. Preoperative consultation with pain or addiction specialists (or both) may be useful for opioid abusers or patient taking methadone to combat addiction if the planned procedure will result in significant postoperative pain.

46. Philippe Richebe Can J Anesth 2009 56:969-981 Perioperative pain management in the patient treated with opioids As a rule, transcutaneous fentanyl or its equivalent should be continued postoperatively as so-called basal analgesia. However, fentanyl absorption can be altered unpredictably depending on type of surgery, amount of fluids administered intraoperatively, and skin temperature at the end of the procedure.

47. Thus, it is preferable in most of these cases to remove the fentanyl patch and to administer an equipotent dose of morphine as a substitute.

48. Equipotent opioid analgesic doses (mg), according to Joly Joly V, Richebe P, Guignard B, et al. Remifentanil-induced postoperative hyperalgesia and its prevention with small-dose ketamine. Anesthesiology 2005; 103: 147–55.

49. Intraoperatively the selection of an opioid remains at the discretion of the anesthesiologis responsible for the patient, and the doses should be titrated following the usual method.

50. Multimodal analgesia • Non-opioidanalgetics: paracetamol, optalgin • NSAIDs • Nerve blocks, regional anesthesia, neuraxial anesthesia, including opioids • Premedication with clonidine, pregabaline /gabapentine • Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, showed its efficiency to reduce hyperalgesia