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Pseudocholinesterase Deficiency: A
Comprehensive Review of Genetic, Acquired,
and Drug Influences
Flanna K. Soliday, CRNA, MSN
Yvette P. Conley, PhD
Richard Henker, CRNA, PhD
Pseudocholinesterase deficiency is an inherited or
acquired condition in which the metabolism of succinylcholine, mivacurium, or ester local anesthetics is
potentially impaired. In this review, genetic inheritance, variants, and testing are examined. Additionally,
acquired conditions and drugs that influence enzyme
activity, as well as possible treatments of the condition, are reviewed.
The review of the literature was conducted by
searching PubMed and Ovid Medline databases, with
no limitation on date of publication. The search was limited to English-language journals only. Additional arti-
utyrylcholinesterase—also known as pseudocholinesterase, serum cholinesterase, plasma
cholinesterase, and false cholinesterase—was
so named due to its ability to hydrolyze butyrylcholine faster than other esters.1 Pseudocholinesterase is produced in the liver and found in most
tissues, with the exception of red blood cells. The presence of pseudocholinesterase in the body has been established for well over half a century. Although potential
functions of this enzyme are debated to this day, its role in
the metabolism of choline esters is universally recognized.
B
Definition of Pseudocholinesterase
Deficiency
Pseudocholinesterase deficiency is a genetic or acquired
alteration in the metabolism of choline esters such as succinylcholine, mivacurium, and ester-linked local anesthetics. The most described consequence of pseudocholinesterase deficiency in the literature is prolonged paralysis
and apnea after administration of succinylcholine or mivacurium. The latter drug is no longer produced in the
United States but is used elsewhere in the world. Less frequently described are adverse outcomes with the use of
ester local anesthetics, particularly chloroprocaine.
Individuals can live their entire lives with pseudocholinesterase deficiency and not experience any untoward health
effects, and the presence of the genetic defect is not realized
until one is exposed to succinylcholine or mivacurium. In
fact, a pseudocholinesterase-deficient group of individuals
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cles of relevance were obtained from reference lists of
previously searched articles and via Internet searches.
Numerous keywords were used in the search, and a
second search was undertaken to find specific citations
about acquired conditions and drugs of relevance.
Nearly 250 articles were obtained and examined for
importance. Fifty articles appear in the review, including case reports, research studies, and review articles.
Keywords: Atypical pseudocholinesterase, BChE,
butyrylcholinesterase, genetic variants, pseudocholinesterase.
in the Vysya community of India were studied, and the determination was made that when individuals were not challenged with drugs or poisons, and did not consume a highfat diet, the absence of butyrylcholinesterase enzyme caused
no adverse health effects.2
Relevance to Anesthesia Providers
Pseudocholinesterase deficiency, whether inherited or acquired, is an important concept to understand for
providers that administer succinylcholine, including
anesthesia, intensive care unit (ICU), emergency department, and perioperative personnel. We must appreciate
basic concepts of genetics, genetic testing, and pharmacogenetics to make informed choices about our plan of
care. We must also be able to extract what diseases, conditions, or medications would cause alterations in a
patient’s enzyme activity and make thoughtful choices
about our care based on this information.
The aim of this review is to examine both the genetic
aspects of pseudocholinesterase deficiency and the acquired aspects to help the reader stay abreast of established and current literature and theories.
Genetics of Pseudocholinesterase Deficiency
Refer to Table 1 for a list of common genetic terms used
throughout this article.
• Inheritance of Atypical Pseudocholinesterase or Pseudocholinesterase Deficiency. Genetically inherited pseudocholinesterase deficiency is typically regarded as an auto-
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313
Term
Definition
Chromosome
Unit of DNA that contains genes. There are normally 23 paired chromosomes (46 total
chromosomes per cell). Consists of 2 arms: the p arm, which is the short arm, and the q
arm, the long arm.
Gene
Occupies a specific area on a chromosome. Consists of DNA and contributes both to the
characteristics of an organism and specific protein coding.
Wild type/typical/normal
Most common version of the gene
Variant
Different version of the gene, with or without consequences to the individual
Allele
Alternate form of a gene occupying a specific area on a chromosome
Homozygous
Two copies of same allele. Using pseudocholinesterase deficiency as an example, a normal
individual would be considered UU—inheriting the same wild-type allele from both parents—
and an individual homozygous for the atypical variant would be considered AA—inheriting
the atypical allele from both parents.
Heterozygous
Two different alleles. Using pseudocholinesterase deficiency as an example, an individual
heterozygous for the atypical variant may be considered UA—inheriting 1 normal copy and 1
variant copy.
Genotype
Appearance of the genetic material
Phenotype
Outward appearance, more commonly described as “what the person looks like.”
Autosomal dominant inheritance
Mode of inheritance that requires only 1 abnormal gene in order to have the condition (eg,
Huntington disease). It is common in this mode of inheritance to see 1 or both parents
affected. The chance of inheriting the disease is 50% if 1 parent is heterozygous for the
mutant gene and the other is homozygous for the normal gene.
Autosomal recessive inheritance
Mode of inheritance that requires both copies of the gene to be abnormal in order to have
the condition; one abnormal gene from each parent is inherited (eg, cystic fibrosis). Typically
the parents are considered carriers and are unaffected. If both parents are heterozygotes for
the abnormal gene, there is a 25% chance of having an affected offspring, a 50% chance of
a carrier offspring, and 25% chance of an offspring with normal genes. Although pseudocholinesterase deficiency is traditionally considered autosomal recessive, the individual can
inherit numerous variants of the gene, including the wild type, and still be considered to
have the condition.
Also, the biochemical characteristics of an organism, eg, blood type.
Table 1. Definitions of Common Genetic Terms
somal recessive trait, although it does not adhere to the
traditional definition completely. Pseudocholinesterase
deficiency is associated with the butyrylcholinesterase or
BChE gene and is located on the long arm of chromosome
3 at 3q26.1-26.2. It is a relatively short piece of genetic
material, making DNA testing for the deficiency fairly
feasible.
• Variants. There are 65 named variants one can inherit
that may result in minimal to extreme postsuccinylcholine apnea and paralysis.3 The most frequently discussed and possibly the most clinically relevant are the
atypical or dibucaine resistant, the fluoride resistant, the
silent, and the K variants. Refer to Table 2 for a list of discussed variants, frequencies, and anesthetic implications
after succinylcholine administration.
• Atypical or Dibucaine Resistant. The existence of a
hereditary link for pseudocholinesterase deficiency had
been speculated on in the literature for decades. In the
mid-20th century the pioneering work by Kalow and
colleagues4,5 showed the presence of a qualitative difference in plasma cholinesterase enzymes of sensitive families compared with the remainder of the population.
They later introduced the dibucaine inhibition test.
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Thus, the first discovered and discussed variant was
the atypical or dibucaine resistant. The local anesthetic
dibucaine was used as an inhibitor, and benzocholine
was used as a substrate to determine the activity of pseudocholinesterase. The term dibucaine number was
coined, meaning the percent inhibition of enzyme activity by dibucaine when a serum or plasma sample is
tested under standard conditions. A dibucaine number
above 70 is described as typical or normal, a number
between 40 and 70 as intermediate (heterozygotes), and
a dibucaine number below 20 as atypical (homozygotes).4,5 An individual with a normal dibucaine number
would react normally to succinylcholine, a heterozygote
would generally be expected to have a normal or minimally prolonged response to succinylcholine, and homozygotes would be expected to have postsuccinylcholine apnea and paralysis lasting near 2 hours or
longer. Frequencies of inheritance vary by population,
but generally heterozygotes can account for 1 in 25 to 1
in 50 individuals, whereas homozygotes can account for
1 in 3,000 individuals.6
• Fluoride Resistant. Shortly after the classification of
variants using the dibucaine number, Harris and
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Variant
Wild type (U)
Atypical (A)/dibucaine
resistant
Fluoride resistant (F)
Frequencya
Reported to be as high
as 98% of the general
population
Homozygote: 1/3,000 1/10,000 (0.03%-0.01%)
Heterozygote: up to
1/25 (4%)
Homozygote:1/150,000
(0.0007%); heterozygous
condition is more
common but less
clinically significant
Activity
Sensitivity
Normal enzyme activity
Normal response to
succinylcholine (UU)
Homozygote: activity
decreased by 70%
Homozygote (AA): very
sensitive
Activity decreased by
60%
Heterozygote (UA): occasional prolonged apnea
Homozygotes (FF):
moderately sensitive
Silent (S)
Homozygous: 1/10,000 8/100,000 (0.01%0.008%); heterozygous
condition is more
common but less
clinically significant
No activity
Homozygotes (SS):
extremely sensitive
Kalow (K)
Homozygous: 1/65
(1.5%); often associated
with other variants
Activity decreased by
30%
Homozygotes (KK): →
mildly sensitive
Estimated paralysis
Normal: ~ 5 min
≥2h
1- 2 h
3 - 4 h or more
<1h
Table 2. Common Genetic Variants Found in Pseudocholinesterase Deficiency and Anesthetic Implications After
Succinylcholineb
a Frequency distribution for the general population; frequencies and existence of different variants vary among different populations.
b Variants can exist by themselves or in combination with other variants, making the response to succinylcholine (or mivacurium) more
variable than as highlighted in the table. This table illustrates only individuals homozygous for 1 specific allelic variant.
Whittaker,7 reported the ability to use sodium fluoride as
an inhibitor in the testing process. Of the individuals
tested, some with normal dibucaine numbers were found
to have low fluoride numbers and some with intermediate dibucaine numbers had even lower fluoride numbers.
This research led to the discovery of the fluoride-resistant
gene. A normal fluoride number is described as 55 to 65.
Homozygotes for this gene would be expected to have a
moderate sensitivity to succinylcholine.7
• Silent Variant. The silent variant, although rare and
complex, results in the relative lack of pseudocholinesterase activity. Reports of individuals who, when tested,
had no pseudocholinesterase activity arose as early as the
1960s. An individual homozygous for the silent variant,
when exposed to succinylcholine or mivacurium, will
have profound paralysis and apnea, relying solely on alternate pathways for elimination of the drug. Frequencies
vary by population, with 1 in 100,000 individuals of
European or American descent being homozygous for the
variant, whereas individuals in the Vysya community of
India have a frequency rate of 4%.1
• K Variant. The K variant is the most common variant
of the BChE gene and is the final variant to be discussed.
The K variant is responsible for a 30% reduction in
enzyme activity, which is of minimal clinical significance
if occurring alone. However, in 89% of cases in which the
atypical variant was identified, the K variant also existed,
making the K variant more clinically significant.8
Additionally, the combination of the K variant and an ac-
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quired deficiency may lower enzyme activity to levels at
which one would see a clinical effect. The recognition of
the K variant is difficult using traditional biochemical
assays, and for this reason many individuals previously
tested may have been misclassified in the past. Accurate
identification of this variant requires DNA sequencing.8
Testing for Pseudocholinesterase Deficiency
• Biochemical Assays. Serum cholinesterase activity
can determine if there is a quantitative defect in enzyme
function. “Normal” is described as 3,200 to 6,600 IU/L.
This number varies by different laboratory standards and
is subject to much interindividual variability. Dibucaine
and fluoride are the most common inhibition tests.
However, there are many other inhibition tests described
in the literature, including chloride, RO2-0683 (one of
the inhibitors used in testing), urea, and succinylcholine.
Although these tests are beneficial in determining
whether a deficiency exists, they are not always accurate
in distinguishing the individual genotype, which requires
genetic testing.9
• Molecular Testing. Polymerase chain reaction (PCR)
is a process used to replicate specific pieces of DNA. The
goal of this test is to identify where and what mutations
or variants exist on a particular piece of DNA. With this
technology qualitative and quantitative variants of the
BChE gene are able to be identified, and correct genotyping can occur.10 Unfortunately, this technology is available only for research purposes at this time.
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Acquired Conditions Affecting Pseudocholinesterase Activity
• Liver Disease. Pseudocholinesterase is primarily synthesized in the liver. When liver function is impaired,
pseudocholinesterase synthesis is also impaired. Decreased serum activities have been shown in many liver
diseases, such as cirrhosis, end-stage liver disease, hepatitis, and liver abscesses. In patients with end-stage liver
disease, normal serum pseudocholinesterase levels were
again seen after liver transplant, with the transplanted
liver assuming the role of production immediately.11,12
Additionally, serum cholinesterase activity may drop 30%
to 50% in acute hepatitis, with a 50% decrease in cirrhosis and chronic malignancies being perhaps among some
of the most substantial decreases of the acquired conditions.13 As the half-life of serum cholinesterase is approximately 10 to 14 days, it is considered an unreliable source
for tracking liver disease.13,14
• Renal Disease. Like liver disease, the literature establishes a clear connection between renal disease and decreased levels of pseudocholinesterase, although the
reasons are not as clear-cut.15,16 Serum cholinesterase activity was found to be up to 2 standard deviations below
normal in 60% of individuals with renal failure who were
studied.15 Further work shows that this decrease cannot
be attributed to the use of dialysis, as previously suspected. Those undergoing renal transplantation experienced
an initial drop in pseudocholinesterase activity, with subsequent normalization approximately 15 days after transplant, roughly the same half-life as the enzyme.17,18
• Malnutrition. Malnutrition is closely linked with
changes in serum albumin and pseudocholinesterase,
likely due to changes in hepatic synthesis of the proteins
and enzymes associated with this disease. In one particular study, 83% of children who were clinically considered
malnourished had serum pseudocholinesterase levels
below the lower threshold of normal. Degenerative
changes of the liver were shown in all 43 samples taken
in this study.19 Although this may be an extreme illustration, as providers we must be aware of these changes
because individuals with varying degrees of malnourishment may present to us—possibly anorexic, elderly,
homeless, or alcoholic individuals. In addition, this information may be substantial for individuals who volunteer their time and efforts in underprivileged areas of the
world. Again, clear case reports exist linking prolonged
paralysis and apnea after succinylcholine administration
in people with malnourishment.
• Pregnancy. Reductions in pseudocholinesterase activity are said to begin approximately in the 10th week of
pregnancy, with further decreases postpartum before normalizing between 10 days and 6 weeks postpartum.20
Activity is said to be reduced 24% during pregnancy, 25%
at 1 day postpartum, and 33% at 3 days postpartum.
These reductions themselves are not clinically significant,
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as it has been suggested that activity needs to be 50% or
less of average activity for individuals to show sensitivity
to succinylcholine.14 More importantly, 60% of individuals with HELLP syndrome (hemolysis, elevated liver
enzymes, and low platelet count occurring in association
with preeclampsia) at the time of the study showed pseudocholinesterase activity below the limit of normal. The
authors speculate this reduction could in fact be clinically significant if exposed to succinylcholine, and they postulated that this effect is due to liver damage seen in
HELLP syndrome.21 It is important to use caution when
choosing an anesthetic plan for the pregnant patient
because normal reductions combined with a genetic
variant could prove clinically significant if exposed to
succinylcholine or an ester local-like chloroprocaine.
• Malignancy. Decreased levels of pseudocholinesterase have been associated with malignancy and carcinoma,
with decreases closely related to the site of primary lesion
and degree of spread.22 Hepatic carcinomas demonstrate
the greatest degree of reductions, followed by lung, gastrointestinal, and genitourinary malignancies, with breast
cancer having a smaller effect on enzyme levels. Evidence
of abnormal cholinesterase gene expression in many
tumor types exists, with great variation among different
tumors.13,23 Consider this information when deciding
which muscle relaxant to use when, for example, securing an airway on an individual with stage IV lung cancer.
• Burns. The size and severity of a burn closely correlates with reductions in pseudocholinesterase activity.24
Lowest levels have been found 5 to 6 days after a burn,
with levels sometimes being depressed 80% or greater,
and in severely burned patients levels remained low up to
4 months after initial injury. It is hypothesized that the
initial drop in activity is due to dilution effect and transcapillary losses, whereas prolonged decreases are due to
hepatic depression of synthesis or release and/or the presence of inhibiting substances in the plasma.24 The importance of this information is questionable, as succinylcholine is essentially contraindicated in the burn patient
because of the risk of hyperkalemia.
• Cardiopulmonary Bypass. A recent study indicates reductions in pseudocholinesterase activity up to 37% with
the initiation of cardiopulmonary bypass, with values remaining low after the termination of bypass.25 This reduction was said to be unrelated to anesthetic technique,
including the use of heparin and aprotinin, but rather
related to hemodilution.25 Like other acquired conditions, the reduction seen here may be of little clinical significance, but in combination with a genetic variant, relevant condition, or presence of a particular drug, the
reduction may be a contributing factor to prolonged
apnea and paralysis after succinylcholine administration.
• Leprosy. Increased incidences of pseudocholinesterase
deficiency have been found in populations with leprosy
compared with control groups.26 The most striking inci-
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Drug
Influence
Noncompetitive cholinesterase inhibitors
Echothiophate eyedrops
Succinylcholine-induced apnea was reached within days of using the eyedrops. Should be
discontinued several weeks before use of succinylcholine is considered.27
Organophosphate insecticides
Many different “brands.” Readily absorbed through bronchi, intact skin, and GI tract. In
acute poisoning, pseudocholinesterase activity is 30%- 50% of normal. Numerous case
reports in literature of prolonged apnea and paralysis after exposure to succinylcholine
and organophosphate insecticides.28- 31
Cyclophosphamide
Dose-dependent reduction in pseudocholinesterase activity 32
Competitive cholinesterase inhibitors
Neostigmine, physostigmine,
pyridostigmine, edrophonium
Case reports of prolonged apnea and paralysis, incomplete antagonism, and potentiation
of blockade when succinylcholine is combined with anticholinesterases including
neostigmine, pyridostigmine, edrophonium, and physostigmine. Considered controversial
for reversal of succinylcholine-induced apnea and paralysis.33 - 36
Tacrine
Used for Alzheimer disease therapy. Was used in the 1960s to increase duration of
paralysis by up to 11 minutes when used with succinylcholine.37
Cocaine
Ester local anesthetic. Up to 50% of cocaine is reported to be metabolized by pseudocholinesterase. Decreased plasma cholinesterase activity is associated with increased
risk of life-threatening cocaine toxicity.38,39
Oral contraceptives
Enzyme activity reduced approximately 20%; likely related to steroid-induced depression
of the liver’s ability to synthesize or secrete into circulation.40
Monoamine oxidase inhibitor: phenelzine Case reports of prolonged apnea and paralysis after ECT when individuals were receiving
phenelzine. Pseudocholinesterase levels normalized after withdrawal from the drug.41
Pancuronium
Enzyme activity reduced up to 40% 45 minutes after a dose. Significant reductions
observed but still considered within normal range.42,43
Bambuterol (oral bronchodilator)
Plasma cholinesterase activity reduced a median of 90%, increasing duration of action of
mivacurium 3 - to 4-fold compared with controls.44
Aspirin
Up to 90% hydrolyzed by cholinesterase. Individuals with pseudocholinesterase
deficiency will hydrolyze aspirin more slowly, possibly prolonging its effects.45
Metoclopramide (Reglan)
Administration may prolong block 2 - 3 minutes; however, if succinylcholine is
administered after metoclopramide, especially in individuals who at baseline have low
activity or deficiency, a clinically significant prolonged block may occur.46
Table 3. Drugs and Pseudocholinesterase
GI indicates gastrointestinal; ECT, electroconvulsive therapy.
dence is found in individuals with lepromatous leprosy, in
which the individual lacks immune resistance to the
Micobacterium leprae organism. Researchers have speculated that there may be a possible genetic link between pseudocholinesterase deficiency and susceptibility to leprosy.26
Drug Influences on Pseudocholinesterase
Refer to Table 3 for a comprehensive list of drugs that influence pseudocholinesterase activities.27-46
• Anesthesia-Related Drugs: Anticholinesterases and
Pancuronium. It is very common, in any given day, to use
an anticholinesterase to reverse a nondepolarizing muscle
relaxant. However, their role in reversing succinylcholineinduced apnea is controversial and has met with mixed
results. Anticholinesterases, by definition, inhibit cholinesterases, thereby inhibiting the breakdown of succinylcholine. The literature is abundant with case reports of
prolonged apnea and paralysis, incomplete antagonism,
and potentiation of blockade when succinylcholine is combined with anticholinesterases, including neostigmine,
pyridostigmine, edrophonium, and physostigmine. It has
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been further suggested that large doses of neostigmine can
cause paradoxical blockade.33-36
Pancuronium is a nondepolarizing muscle relaxant,
which possesses some anticholinesterase activity. Early
publications show a depression of serum cholinesterase
of 40% up to 45 minutes after injection of pancuronium.42 More recently, individuals with the normal genotype were given standard clinical doses of pancuronium
for elective surgical procedures. Nearly all individuals
showed a statistically significant decrease in pseudocholinesterase activity, but all levels were considered to be in
the normal range.43 Again, the clinical significance of
these findings may be questioned, because pancuronium
is used for procedures in which a longer period of relaxation is required and reductions in enzyme activity do not
reach a clinically significant level.
Although many of the drugs mentioned in Table 3 do
not cause clinically relevant reductions in pseudocholinesterase activity, they are important to recognize.
Whereas drugs, certain genetic variants, or acquired conditions alone may not be enough to see prolonged paral-
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317
GeneTests51
Offers comprehensive information about genetic testing for various disorders and laboratories that
perform specific genetic tests. GeneReviews within the site offers comprehensive information
about various genetic disorders.
Currently genetic testing is not available to the public for atypical pseudocholinesterase; however,
much genetic testing is being done through research laboratories.
OMIM—Online Mendelian
Inheritance in Man52
Offers a database that is a catalog of human genes and genetic disorders
Table 4. Genetics Websites to Watch
ysis and apnea following succinylcholine administration,
the combination of them could result in a clinically significant scenario.
Treatment of Pseudocholinesterase Deficiency
There is no cure for pseudocholinesterase deficiency.
However, there are interventions in the literature that
serve to, in some cases, speed the onset of recovery once
an individual is exposed to succinylcholine or mivacurium. Administration of whole blood, fresh frozen plasma,
and human serum cholinesterase are some of the interventions discussed in the literature.47-50 The standard of
care is widely advocated as letting the individual recover
spontaneously.
Administration of whole blood has been successfully
described in the literature as reversing prolonged apnea
and paralysis after the administration of succinylcholine
in individuals with pseudocholinesterase deficiency.47
Fresh frozen plasma has been met with some controversy, because it shows acceleration of recovery in some individuals and no effect in others.48,49 Even though blood
and blood product transfusion is generally considered
safe, some question why we would unnecessarily expose
an individual to a transfusion when it has been clearly established that spontaneous recovery occurs without any
undo effects.
Another treatment described in the literature is the use
of human serum cholinesterase, which like other interventions, has proved to shorten the recovery time. The
product is considered safe, and the disease transmission
risk is said to be comparable to that of human albumin.50
This may be a viable option, but a review of the literature
shows that this product is expensive and is not available
in the United States.
Although multiple interventions have been described
in the literature to speed the onset of recovery from prolonged paralysis and apnea in the pseudocholinesterasedeficient patient, these interventions may pose an unnecessary risk. All individuals will eventually recover
spontaneously from prolonged paralysis and apnea, with
time to recovery depending on both genetic and acquired
factors. It is widely advocated that the best and safest
“treatment” is to let the individual recover spontaneously. Once it is suspected that an individual may be pseudocholinesterase deficient, appropriate laboratory work
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should be drawn and sent off to identify if the individual
is pseudocholinesterase deficient. At the same time, it is
important to communicate with the patient to help alleviate any distress he or she might be feeling, and then to
sedate the patient in the postanesthesia care unit (PACU)
or ICU setting until patient recovery is sufficient to meet
extubation criteria. Furthermore, the literature describes
the need for family members to be tested and all those
with pseudocholinesterase deficiency to carry a medical
identification (ID) card or bracelet.
Summary
Pseudocholinesterase deficiency is a genetic or acquired
condition in which the metabolism of succinylcholine,
mivacurium, and ester local anesthetics could potentially
be impaired. The most recognizable feature of this deficiency is prolonged periods of apnea and paralysis following clinical doses of succinylcholine or mivacurium.
Healthcare providers must have an understanding of the
genetics of the deficiency as well as conditions and drugs
that can alter enzyme activity in order to effectively communicate with patients, their families, and colleagues
about this disorder. Helpful websites51,52 on genetics are
listed in Table 4.
Several different genetic variants exist, each with their
own anesthetic implications. Growing genetic research
points to different variants coexisting, further prolonging
apnea and paralysis after succinylcholine administration.
In particular, the K variant alone produces a decrease in
enzyme activity of only 30% but when paired with other
variants, acquired conditions, or drugs, it can result in reductions of enzyme activity to clinically significant levels.
The importance of a thorough preoperative evaluation, including personal and family history, cannot be overemphasized in the detection of a possible deficiency, whether
genetic or acquired.
All anesthesia providers should employ the use of a peripheral nerve stimulator when using any muscle relaxant,
including succinylcholine. Recovery of twitches should be
ensured before administering a nondepolarizing muscle
relaxant. If the patient shows no response to train-of-4
stimulation after 15 minutes, and after appropriate troubleshooting, the provider should suspect a pseudocholinesterase deficiency. Appropriate, facility-dependent laboratory work should be immediately sent off. These tests
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may include serum pseudocholinesterase activity and
dibucaine and fluoride inhibition tests. Efforts should be
made to inform the patient of the events in an effort to alleviate stress. The patient should be sedated and ventilated in the PACU or ICU setting until extubation criteria is
met. If this situation is encountered in an outpatient
surgery center, the patient should be transferred to a facility for longer-term ventilation and sedation.
The most widely advocated method of “treatment” of
pseudocholinesterase deficiency is spontaneous recovery.
It is the job of the healthcare provider to communicate to
the patient and family members information about the
condition, implications, inheritance, and testing. Individuals with inherited deficiency should carry a medical
ID card or bracelet indicating that they have pseudocholinesterase deficiency and should be encouraged to disclose this information to all healthcare providers. Again, a
sound knowledge base regarding all aspects of this condition will help healthcare providers to provide accurate information to patients, families, and colleagues.
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AUTHORS
Flanna K. Soliday, CRNA, MSN, is a staff nurse anesthetist at Forbes
Regional Campus of the Western Pennsylvania Hospital, Monroeville,
Pennsylvania. At the time this article was written, she was a student at the
University of Pittsburgh, Nurse Anesthesia Program, Pittsburgh, Pennsylvania. Email: [email protected].
Yvette P. Conley, PhD, is an associate professor of nursing and human
genetics at the University of Pittsburgh. Email: [email protected].
Richard Henker, CRNA, PhD, is an associate professor and vice chair
of the Acute/Tertiary Care Department at the University of Pittsburgh
School of Nursing. Email: [email protected].
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