Transcript ConfN°20403-ColombiaIIicitDrugs

The drug-abusing parturient
Mike Paech
Professor and Chair of Obstetric Anaesthesia
School of Medicine and Pharmacology, The University of Western Australia
Dept. of Anaesthesia & Pain Medicine,
King Edward Memorial Hospital for
Women & Royal Perth Hospital
No disclosures or conflicts of interest
Western Australia
Disclosures & Definitions
I am on a Clinical Advisory Panel for MSD
Substance misuse (abuse) is the harmful use of
drugs for non-medical purposes.
Please consider this patient
You are called to the assessment area of your maternity unit by the
obstetric team, who want you to review and help manage a 23 year old
woman at 32 weeks gestation in her first pregnancy. The patient is
accompanied by a male friend.
• No antenatal care
• Presents with severe abdominal pain
• Pink breathing air, HR 130, BP 165/95 mmHg, temp 37.6 C
• Sweating, restless, poorly cooperative, appears dehydrated
• Has a tense, moderately tender uterus. Fetal tachycardia of
165 bpm
• History of smoking, alcohol abuse and illicit drug use (heroin
and amphetamines)
• Claims is ‘clean’ and on methadone program, 60 mg/day
Case history
• Ultrasonography shows a small retroplacental clot
• Venous blood required for antenatal screening tests,
including full viral status; and for blood picture, crossmatch, coagulation tests, electrolytes, renal and liver
function. Veins are thrombosed
• You find it difficult to get a coherent and comprehensive
history from the patient but she tells you –
hepatitis C positive; no medical disease; no surgery;
allergic to anti-inflammatory drugs and tramadol
• On examination she is underweight, has very poor venous
access, eroded teeth, a soft systolic murmur and bi-basal
crepitations
Her friend approaches you outside the room and reveals
that the patient has not been taking her methadone
regularly over recent weeks.
She has been intermittently using heroin, although a few
hours previously, prior to the onset of the abdominal
pain, she had injected ‘ice’ (methamphetamine).
Quiz – match the picture to a drug
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Marihuana (marijuana)
Heroin
G- hydroxybutyrate
Nitrous oxide
Methamphetamine
Cocaine
Hallucinogenic drugs
Quiz – match the picture to a drug
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•
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•
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Marihuana (marijuana)
Cocaine
G-hydroxybutyrate
Nitrous oxide
Methamphetamine
Heroin
Hallucinogenic drugs
Commonly abused depressant drugs
‘Street names’
1.Ethanol (alcohol)
grog; booze; brew;
hooch; etc
2. Marihuana/marijuana (cannabis)
weed; grass; pot; ganja;
dope; hash; mary jane; etc
3. Benzodiazepines
Valium (Vs); downers
tranks; benzos; etc
Main action
Modulator GABAA R
Antagonist NMDA R
Agonist cannabinoid R
Bind GABAA R
4. Opioids
skag; horse; shit; junk;
Harry boy; white nurse;
brown sugar; cotton; kicker;
oxies; etc
Agonist opioid R
5. Gamma-hydroxy butyrate
Agonist GABAB R
GHB; gamma-OH;
Agonist GHB R
fantasy; liquid E;
grievous bodily harm; juice; G; etc.
6. Inhaled solvents (benzene; toluene; acetone; nitrites; etc)
glue; gas; sniff; poppers; bulbs;
air blast; nangs; bolt; etc.
Modulate GABA R
Inhibit DNA synthesis
Commonly abused stimulatory drugs
1. Nicotine
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Nicotinic ACh R agonist
2. Methamphetamine and derivatives
speed; uppers; ice; crystal;
fet; powder; dexies; ecstasy;
Increase release, block reuptake or inhibit metabolism
of excitatory
neurotransmitters
(norepinephrine, dopamine, serotonin)
3. Cocaine
crack; coke; candy; snow;
flake; gold dust; line; etc.
4. Ketamine & designer drugs
Special K; K; cat Valium; purple;
super C; bump
Serotonin-norepinephrinedopamine reuptake
inhibitor
Na-channel block
Antagonist NMDA R
Binds multiple others
The extent of drug abuse
Legal drugs
Life-time prevalence of drug abuse or addiction is 10-15% in
the community and that includes doctors (and
anesthesiologists!)….but only 1% of doctors receive therapy
Illegal (illicit) drugs
Most people have used an illicit drug at some time but most
are not drug abusers (drug abuse estimated 8% pop. in USA)
…..and many drug abusers maintain normal function
And some are cult heroes……
In Australia 5% of the population use cannabis regularly
Drug abuse during pregnancy
In the USA 10-16% pregnant women use alcohol or smoke
tobacco.
Reported rates of illicit drug use during pregnancy are 4-7%
- but 16% among those aged 15-17 years.
The extent of the problem
Many illicit drug users deny use!
The stereotype obstetric intravenous drug user:
– A smoker with personal and social issues; anxiety,
depression or other psychiatric conditions; and poor
health and nutrition.
– History of a lack of antenatal care and previous
premature labor.
– Medical problems such as anemia, hepatitis, sexually
transmitted disease and urinary tract infection
These women create extra work
Up to 10% of hospitalized pregnant substance abusers
suffer a life-threatening crisis
So what are the major substances of abuse?
No. 1 A legal drug – ethanol (ethyl alcohol)
Acute intoxication increases aspiration risk (give
pharmacological prophylaxis and protect airway)
Chronic use is associated with:
Cardiac or liver failure
– appropriate anesthetic drugs & doses?
– regional anesthesia contraindicated by coagulopathy or
infection?
Maternal withdrawal syndrome
Fetal alcohol syndrome (estimated 1 in 100 in USA)
No. 2 Nicotine & marihuana
Nicotine
Adverse obstetric outcomes
Bronchospasm, secretions, postop respiratory morbidity
•
use regional anesthesia whenever possible
•
arrange appropriate postoperative respiratory care
•
advise abstinence > 48 hours prior to anesthesia
Hepatic enzyme induction
•
titrate intravenous anesthetics
Marihuana
Oropharyngitis, uvular oedema (assess airway)
Altered conscious state (agitation or sedation)
Increased propofol requirements for airway instrumentation
No. 3 Stimulants - Methamphetamine
Methamphetamine is probably the most abused illicit drug
(in Australia 3% vs 1% heroin; cocaine (1%) predominates in
USA)
Obstetric implications
– increased rates of premature delivery, low birth
weight, stillbirth, neonatal death & low IQ
– obstetric hemorrhage, esp. placental abruption (10%
among regular cocaine users)
Issues for anesthesia
Acute intoxication
Hypertension, myocardial ischemia, arrhythmias
– caution with sympathomimetics and use less
arrhythmogenic anesthetic drugs
Seizures - exclude eclampsia
Fetal distress and placental abruption
Serotonergic syndrome / sudden death
Regular users have decreased anesthetic dose requirements
but need more in acute intoxication
– no cross-tolerance with opioids / benzos so easy to
overdose
– regional block depends on level of cooperation & risk of
coagulation defects
Cocaine
Hypertension, seizures
– exclude eclampsia
– treat with midazolam, alpha2-agonists, hydralazine,
glyceryl trinitrate or nifedipine (possibly labetolol but
avoid beta-blockers).
– obtund the intubation response (GTN, magnesium
sulphate, esmolol, high-dose opioid e.g. remifentanil)
Myocardial ischemia, infarction, arrhythmias, local vascular
comps
– use alpha2-agonists (clonidine, dexmedetomidine) to aid
BP control
– use less arrhythmogenic anesthetic drugs
Cocaine
Thrombocytopenia
– decide if regional anesthesia is contraindicated
Poorer response to opioid
– titrate doses to effect
Cholinesterase depletion
– reduce dose of & monitor succinylcholine
(suxamethonium)
Ketamine & hallucinogens
Seizures - distinguish from eclampsia
Caution with sympathomimetic drugs
Autonomic dysregulation
– control labile blood pressure and tachycardia to prevent
cardiomyopathy, coronary and cerebral vasospasm
Reduced plasma cholinesterase activity
– reduce dose & monitor succinylcholine
No. 4 Opioids
In USA dependency or abuse in pregnancy is increasing –
0.4% (1 in 200) in 2011
Prescription opioid abuse is up greatly in USA
[Maeda A et al Anesthesiol 2014; n=113,000 in 57 mil delivery admissions]
Opioids & pregnancy
Obstetric implications
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prematurity, IUGR, stillbirth, neonatal mortality
maternal abruption, C-section, increased length of stay
maternal death during hospitalization (OR 4.6)
neonatal abstinence syndrome
Maintenance when pregnant
– increase methadone dose (> 40 mg/day) or continue
buprenorphine dose as necessary to prevent heroin use
– provide partial substitution of maintenance opioid dose
perioperatively
Anesthesia-relevant problems
Acute opioid intoxication
Titrate anesthetic drugs (reduced requirements?)
Chronic use
IF IV opioid, difficult intravenous access
– use ultrasound guidance and consider neck veins
Infection risk, chronic hepatitis, malnutrition
– check liver function
Titrate anesthetic drug (increased requirement?)
Opioid-induced hyperalgesia / tolerance
Opioids
Beware maternal withdrawal syndrome (24-48 h)
– During labour substitute usual dose with an equivalent
dose of oral or parenteral opioid ….or use epidural
opioid plus current oral prescription
– Postop or postpartum recommence usual opioid dose
immediately as well as providing additional regional or
systemic analgesia
– Avoid methadone for acute pain if on maintenance
– Avoid opioid antagonists
– Treat withdrawal with clonidine or dexmedetomidine;
midazolam; doxepin and diphenhydramine; loperamide;
beta-blockers
No. 5 Benzodiazepines & GHB
Acute intoxication - provide supportive therapy
Chronic use
Titrate anesthetic drugs (increased requirement?)
Risk of withdrawal syndromes (delirium, seizures,
hyperthermia, autonomic instability)
No. 6 Other substances
Solvents
Sensory/motor deficits
– perform neurological examination prior to regional
Tramadol
Seizures - distinguish from eclampsia
Withdrawal syndrome
– provide supportive therapy
Remember multidrug (polydrug) abuse is common
Back to our patient…
You are called to the assessment area of your maternity unit by the
obstetric team, who want you to review and help manage a 23 year old
woman at 32 weeks gestation in her first pregnancy. The patient is
accompanied by a male friend.
• No antenatal care
• Likely abruption and current use of IV heroin &
metamphetamine
• In pain, agitated, hypertensive, dehydrated
• Difficult veins
You are going to have to look after her now and for
C-section!
In addition to usual preoperative assessment,
what are the main initial management
considerations?
1.
Obtain her cooperation (give analgesics & possibly
drugs to reduce agitation)
2. Get venous access to allow blood testing, rehydration
and IV drug administration
3. Confirm ongoing obstetric surveillance to exclude
significant maternal blood loss and observe fetal status
4. Review blood gases, blood counts and coagulation tests
to exclude contraindications to regional anesthesia and
to correct existing abnormalities
What are the priorities for her preoperative medical
management and planning?
1.
2.
3.
4.
5.
Assessment of her intravascular volume status and
correction of hypovolemia
Treat hypertension with titrated vasodilators or
labetolol
Review her history and blood tests to exclude severe
preeclampsia & other abnormalities
Performing a sepsis and drug screen
Consult with the operating room team and HDU staff
to inform them of her need for surgery and wellmonitored postoperative care
Which are the likely anesthetic challenges ?
1.
Difficulty deciding whether she is likely to tolerate
surgery when awake under regional block, or whether
general anesthesia is advisable
2. Intraoperative pain control during surgery if under
spinal anesthesia
3. An increased risk to staff of cross-infection
4. Achieving good quality pain relief – likely difficult due
tolerance and hypersensitivity unless regional analgesic
techniques are used
The analgesia plan should include an agreement with her
about the duration of perioperative opioid
administration & post-discharge referral to a
community or hospital opioid-management program
Options for satisfactory postoperative analgesia are • Low thoracic epidural infusion of low concentration local
anesthetic and lipophilic opioid, possibly also with clonidine,
for up to 48 hours
• Bilateral TAP blocks or continuous wound infiltration
followed by patient-controlled intravenous tramadol or
fentanyl & adjuncts
• Intrathecal morphine 250 mcg or more followed by
patient-controlled intravenous analgesia
• Epidural morphine 5 mg boluses plus adjuncts
Analgesic adjuncts
– IV ketamine infusion starting at 0.1 mg/kg/h
– gabapentin or pregabalin (150 mg bd)
– tapentadol SR (100 mg bd)
Back to the patient…………..
You talk to the obstetricians, who arrange a cat 3 C-section
after investigations and stabilization over the next hour or
two (the fetal condition remains OK).
You • give her oral clonidine, insert an IV cannula under
ultrasound guidance and do ‘labs’.
• titrate IV fentanyl & midazolam until she is more
comfortable and cooperative.
• give IV fluid and correct her hypertension with oral
nifedipine
• obtain her consent for regional anesthesia (a CSE) and/or
general anesthesia (plan B) – with final decision later, based
on blood results and her mental state.
• obtain her agreement about a plan for postop analgesia.
Her hemodynamic status improves & she is much more
cooperative.
You perform a double segment CSE anesthetic (low lumbar
IT bupivacaine, morphine and clonidine; low thoracic epidural
catheter)
The C-section is uneventful apart from mild intraoperative
pain managed with pelvic LA; nitrous oxide. The neonate is in
good condition but goes to special care nursery for
observation.
She is nursed in the high-dependency unit, under the care of
pain specialists & obstetricians; and observed for signs of
opioid and alcohol withdrawal.
Oral methadone is recommenced immediately postop and a
low dose of oral clonidine continued.
Thromboprophylaxis with low molecular weight heparin is
commenced.
She gets excellent pain relief with her thoracic PCEA for 2
days; and then adequate relief with oral acetaminophen
(paracetamol), celecoxib, tapentadol, pregabalin.
She is investigated for cardiac or pulmonary pathology
(SBE? sepsis?).
Post-discharge Community Drug and Alcohol unit follow-up is
organized by obstetricians.
Key points
• Drug abuse during pregnancy is not uncommon but
may be difficult to detect and is frequently
denied
• The most commonly abused drugs are alcohol,
tobacco and cannabis; amphetamines, cocaine and
opioids
• Adverse maternal outcomes include morbidity
from acute intoxication or withdrawal (esp.
alcohol, opioids, stimulants) and obstetric
morbidity such as placental abruption (stimulants,
opioids)
Key points
• Adverse fetal and neonatal outcomes include
impaired placental function and premature
delivery (stimulants, opioids), neonatal withdrawal
syndromes (opioids, benzodiazepines, tramadol)
or developmental abnormalities (neonatal alcohol
syndrome)
• Medical, obstetric and other disease or
pathology (pre-eclampsia / eclampsia, infection,
hepatic disease, anemia) should be excluded
before assuming acute drug intoxication is the
sole cause of presenting symptoms and signs
Key points
• The acutely intoxicated woman poses challenges
due to lack of cooperation, difficult venous
access, physiological derangements (coma and
respiratory depression from opioids, excessive
sympathetic activity from stimulants) and the
need for urgent delivery
• Substance abusing women are more likely to
require additional analgesic and anesthetic
services and pain management may be very
difficult (opioids)
Key points
• Regional anesthetic challenges include psychological
suitability; relative contraindications such as
infection or coagulopathy; and poorer or greater
responses to vasopressors (use direct-acting).
CSE techniques are advantageous.
• GA challenges include altered drug requirements &
exaggerated response to intubation.
References
1. Scott K, Lust K. Illicit substance use in pregnancy – a
review. Obstet Med 2010;3:94-100
2. Wendell AD. Overview and epidemiology of substance
abuse in pregnancy. Clin Obstet Gynecol 2013;56:91-96
3. Bell J, Harvey-Dodds L. Pregnancy and injecting drug use.
BMJ 2008;336:1303-1305
4. French E. Substance abuse in pregnancy: compassionate
and competent care for the patient in labor. Clin Obstet
Gynecol 2013;56:173-177
5. Hall AP, Henry JA. Illicit drugs and surgery. Int J Surg
2007;5:365-370
7. Slamberova R. Drugs in pregnancy: the effects on mother
and her progeny. Physiol Res 2012;61 (S1):S123-135
THANKS!