Title: Subject Characteristics
1Hyperventilation syndrome BYAHMAD YOUNES
PROFESSOR OF THORACIC MEDICINE Mansoura faculty
of medicine
2Hyperventilation syndrome
- Hyperventilation syndrome (HVS) represents a
relatively common emergency department (ED)
presentation that is readily recognized by most
clinicians. - The underlying patho-physiology has not been
clearly elucidated. - HVS is a condition in which minute ventilation
exceeds metabolic demands, resulting in
hemodynamic and chemical changes that produce
characteristic dysphoric symptoms. - Inducing a drop in PaCO2 through voluntary
hyperventilation reproduces these symptoms. - Many patients with HVS do not manifest low PaCO2
during attacks.
3Hyperventilation syndrome
- A better term for this syndrome might be
behavioral breathlessness or psychogenic dyspnea,
with hyperventilation seen as a consequence
rather than a cause of the condition. - Some patients may be physiologically at risk for
the development of psychogenic dyspnea. - Symptoms of HVS and panic disorder overlap
considerably, though the 2 conditions remain
distinct. - Approximately 50 of patients with panic disorder
and 60 of patients with agoraphobia manifest
hyperventilation as a symptom, whereas only 25
of patients with HVS manifest panic disorder.
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5The Diagnostic and Statistical Manual of Mental
Disorders, Fourth Edition, classifies the anxiety
disorders into the following categories
- Anxiety due to a general medical condition
- Substance-induced anxiety disorder
- Generalized anxiety disorder
- Panic disorder
- Acute stress disorder
- Posttraumatic stress disorder (PTSD)
- Adjustment disorder with anxious features
- Obsessive-compulsive disorder (OCD)
- Social phobia
- Specific phobia and agoraphobia
6Hyperpnea or hyperventilation
- Hyperpnea or hyperpnoea is increased depth of
breathing when required to meet metabolic demand
of body tissues, such as during or following
exercise, or when the body lacks oxygen
(hypoxia), for instance in high altitude or as a
result of anemia. - Tachypnea differs from hyperpnea in that
tachypnea is rapid shallow breaths, while
hyperpnea is deep breaths. - In hyperpnoea, the increased breathing rate is
desirable as it meets the metabolic needs of the
body. - In hyperventilation, the rate of ventilation is
inappropriate for the body's needs (except in
respiratory acidosis, when CO2 needs to be
breathed off). The resulting decrease in CO2
concentration results in the typical symptoms of
light-headedness, tingling in peripheries, visual
disturbances etc. In hyperpnoea, there are
generally no such symptoms .
7Panic Disorder
- Panic disorder is characterized by the
spontaneous and unexpected occurrence of panic
attacks, the frequency of which can vary from
several attacks per day to only a few attacks per
year. - Panic attacks can occur in other anxiety
disorders but occur without discernible
predictable precipitant in panic disorder - To make the diagnosis of panic disorder, panic
attacks cannot directly or physiologically result
from substance use, medical conditions, or
another psychiatric disorders
8Panic attacks are a period of intense fear in
which 4 of 13 defined symptoms develop abruptly
and peak rapidly less than 10 minutes from
symptom onset.
- Palpitations
- Sweating
- Trembling or shaking
- Sense of shortness of breath or smothering
- Feeling of choking
- Chest pain or discomfort
- Nausea or abdominal distress
- Feeling dizzy, unsteady, light-headed, or faint
- Derealization or depersonalization (feeling
detached from oneself) - Fear of losing control or going crazy
- Fear of dying
- Numbness or tingling sensations
- Chills or hot flashes
9Collectively, phobic disorders (social phobia,
specific phobia, and agoraphobia) are the most
common forms of psychiatric illness, surpassing
the rates of mood disorders and substance abuse
- Agoraphobia is defined as anxiety toward places
or situations in which escape may be difficult or
embarrassing - Most cases of agoraphobia develop as a
complication of panic disorders. - A person previously experiences a panic attack in
a specific situation or environment and this
triggers a vicious circle. - They begin to worry so much about having a panic
attack again that they feel the symptoms of panic
attack returning when they are in a similar
situation or environment. This then causes the
person to avoid that particular situation or
environment.
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11Conversion disorder, factitious disorder,
and malingering
- Conversion disorder, factitious disorder,
and malingering have one major characteristic in
common they represent conditions that are not
real. - Properly diagnosing your patient with one of
these psychiatric ailments will allow you to
create appropriate plans of care for your
patients .
121. Conversion Disorder is a psychiatric
condition that results in a neurological complaint
or symptom, without any underlying neurological
cause.
- Patients may experience seizures (i.e.
pseudo-seizures), weakness, non-responsiveness,
numbness, and even vision loss. - The symptoms are not intentional, yet upon
further investigation no biological explanation
for the symptoms can be found. - The name conversion disorder formerly known as
"hysteria", comes from Sigmund Freud who stated
that stress can cause a psychiatric ailment to
convert to a medical problem. - It is thought that symptoms arise in response to
stressful situations affecting a patient's mental
health.
132. Factitious Disorder (Munchausen Syndrome )
- Factitious Disorder (a Somatoform Disorder) is a
condition where patients intentionally fake
disease, or intentionally cause disease in order
to play the patient role. - The main distinction between this and conversion
disorder is the intentional nature of factitious
disorder. - Often referred to a factitious disorder is
characterized by patients frequently feigning
illness to obtain attention, sympathy, or other
emotional feedback. - They achieve this goal through exaggerating
symptoms, deliberately faking symptoms, or even
intentionally creating real symptoms.
14Münchausen syndrome by proxy
- Münchausen syndrome by proxy (MSbP or MBP) is a
term that is used to describe a behavior pattern
in which a caregiver deliberately exaggerates,
fabricates, and/or induces physical,
psychological, behavioral, and/or mental health
problems in those who are in their care. - With deception at its core, this behavior is an
elusive, potentially lethal, and frequently
misunderstood form of child abuse or medical
neglect that has been difficult to define, detect
and confirm.
153. Malingering
- Malingering is the intentional faking or creating
of illness in order to obtain secondary gain
(e.g. workers compensation, disability payments,
avoiding work or jail time, pain medication,
etc.). - Malingering is NOT a psychiatric illness this is
the first major distinction from the other two
disorders. - Malingering is an intentional abuse of the
medical system to obtain personal benefit. - Malingerers abuse the system to obtain secondary
gain while patients with factitious disorder
attempt only to obtain emotional, or primary
gain. In simpler terms, the end goal of a
malingerer usually involves monetary value, while
the goals of patients with factitious disorder
have no such value
16QUICK REVIEW
- Conversion Disorder Unintentional, due to
emotional stressors, no gain to the patient - Factitious Disorder (Munchausen) Intentional,
primary or emotional gain - Malingering Intentional, secondary and often
monetary gain.
17Pathophysiology of HVS
- Acute HVS accounts for only 1 of cases but is
more easily diagnosed. - Chronic HVS can present with a myriad of
respiratory, cardiac, neurologic, or
gastrointestinal (GI) symptoms without any
clinically apparent over-breathing by the
patient. - Because of the subtlety of hyperventilation, many
patients with chronic HVS are admitted and
undergo extensive and expensive testing in an
attempt to discover organic causes of their
complaints. - Certain stressors provoke an exaggerated
respiratory response, including emotional
distress, sodium lactate, caffeine,
isoproterenol, cholecystokinin, and Co2 .
18Pathophysiology
- Patients with HVS were shown to be more likely to
have had overprotective parents when they were
children. A sudden stressful situation later in
life can then incite the first episode of HVS. - Infusion of lactate provokes symptoms of panic in
80 of patients with panic disorder but in only
10 of controls. Approximately one half of the
lactate responders develop acute hyperventilation
as part of the panic reaction. - Lactate levels are higher and remain elevated
longer in patients with panic disorder than in
controls, suggesting that abnormal metabolism of
lactate is involved in the pathogenesis,
19Pathophysiology
- Patients with HVS tend to breathe by using the
upper thorax rather than the diaphragm, and this
results in chronic over-inflation of the lungs. - When stress induces a need to take a deep breath,
the deep breathing is perceived as dyspnea. - The sensation of dyspnea creates anxiety, which
encourages more deep breathing, and a vicious
circle is created.
20Pathophysiology
- Patients with panic disorder have a lower
threshold for the fight-or-flight response. - In susceptible patients, even minor stresses can
trigger the syndrome, which then tends to
manifest with primarily psychiatric complaints
(eg, fear of death, impending doom, or
claustrophobia). - It is believed that HVS patients tend to focus on
somatic complaints related to the physiologic
changes produced by hyperventilation. - Initiating stimuli and abnormal stress responses
may be identical but are expressed differently in
each group.
21Etiology
- The cause of HVS is unknown, but some persons who
are affected appear to have an abnormal
respiratory response to stress, sodium, lactate,
and other chemical and emotional triggers, which
results in excess minute ventilation and
hypocarbia. - In most patients, the mechanics of breathing are
disordered in a characteristic way. When
stressed, these patients rely on thoracic
breathing rather than diaphragmatic breathing,
resulting in a hyper-expanded chest and high
residual lung volume. - Because of the high residual volume, they are
then unable to take a normal tidal volume with
the next breath and consequently experience
dyspnea.
22Etiology
- Proprioceptors in the lung and chest wall signal
the brain with a suffocation alarm that
triggers release of excitatory neurotransmitters
that are responsible for many of the symptoms
such as palpitations, tremor, anxiety, and
diaphoresis. - The incidence of HVS is higher in first-degree
relatives than in the general population, but no
clear genetic factors have been identified.
23Epidemiology
- As many as 10 of patients in a general internal
medicine practice are reported to have HVS as
their primary diagnosis. - The peak incidence is between the ages of 15 and
55 years, but cases have been reported in all age
groups except infants. - HVS has a strong female preponderance the
female-to-male ratio may be as high as 71.
24Prognosis
- Patients with chronic HVS experience multiple
exacerbations throughout their lives. - Children who experience acute HVS often continue
this pattern into adulthood. - Many patients have associated disorders (eg,
agoraphobia) that may dominate the clinical
picture. - Patients who are treated with breathing
retraining, stress reduction therapy, and various
medications (eg, benzodiazepines or selective
serotonin reuptake inhibitors SSRIs) experience
significant reductions in the frequency and the
severity of exacerbations. - Death attributable to HVS is extremely rare.
25Prognosis
- A leftward shift in the oxyhemoglobin
dissociation curve and vasospasm related to low
PaCO2 could cause myocardial ischemia in patients
with coronary artery disease (CAD) and
hyperventilation syndrome. - Certain patients are disabled psychologically by
their symptoms, and many patients carry false
diagnoses. - Patients with HVS often undergo unnecessary
testing and suffer from the complications of
these interventions (eg, angiography,
thrombolytics, or nasal reconstruction). - Withholding such therapy may be difficult in a
patient with crushing chest pain and dyspnea. the
chronicity of the condition often causes
different physicians to repeat these unnecessary
investigations. -
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27Patient Education
- Patients should receive
- 1- Clear explanation of the underlying
patho-physiology and - 2- should be instructed in the technique of
deflation of the upper chest followed by
controlled diaphragmatic breathing.
28Complications
- The complications encountered in patients with
this syndrome are related mainly to the invasive
procedures and investigations (eg, angiography)
that are used in the workup of HVS . - Complications may also occur as a result of
symptoms produced indirectly by hyperventilation
(eg, injuries sustained in a fall during a
syncopale episode attributable to
hyperventilation).
29Screening for OSA prior to surgery
- Pulse oximetry as a single metric of sleep apnea
lacks the sensitivity and specificity of PSG and
multi-channel home sleep testing. - If the goal is only to cipher out those with an
AHI of 15 or 20 or more, pulse oximetry can be
considered. - Centers for Medicare and Medicaid Services, 2009
reported that the final decision supporting
equally effective testing utilizing PSG and home
sleep tests, as measured by outcomes and patient
compliance. - While patients with mild OSA may not require
preoperative PAP therapy, patients with moderate
and severe OSA who have been on PAP therapy
should continue treatment in the preoperative
period . - Patients who have been noncompliant with
instructions for CPAP use prior to surgery and
are in need of CPAP post-surgery, pose the
highest risk of potential complications.
30Acute hyperventilation
- Patients often present dramatically, with
agitation, hyperpnea and tachypnea, dyspnea,
wheezing, chest pain , dizziness, palpitations,
tetanic cramps (eg, carpopedal spasm),
paresthesias, generalized weakness, and Syncope.
The patient often complains of a sense of
suffocation. - An emotionally stressful precipitating event can
often be identified. - Wheezing may be heard because of broncho-spasm
from hypo-carbia.
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32Carpopedal spasm occurs when acute hypocarbia
causes reduced ionized calcium and phosphate
levels, resulting in involuntary contraction of
the feet or (more commonly) the hands .
33Cardiac symptoms
- The chest pain associated with HVS usually has
atypical features, but on occasion, it may
closely resemble typical angina. - It tends to last hours rather than minutes, and
is often relieved rather than provoked by
exercise. It is usually unrelieved by
nitroglycerin. - The diagnosis of HVS should be considered in
young patients without cardiac risk factors who
present with chest pain, particularly if the pain
is associated with paresthesias and carpo-pedal
spasm. - ECG abnormalities may include prolonged QT
interval, ST depression or elevation, and T-wave
inversion.
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35Cardiac symptoms
- In patients with subcritical coronary artery
stenosis, the vasospasm induced by hypocarbia may
be sufficient to provoke myocardial injury. - The incidence of HVS is high among patients with
mitral valve prolapse (MVP), and the chest pain
associated with MVP may be due to
hyperventilation. - Prinzmetal angina (ie, coronary artery vasospasm)
is triggered by HVS, but the chest pain
associated with this syndrome normally would be
expected to respond to nitrates or calcium
channel blockers.
36Central nervous system symptoms
- Central nervous system (CNS) symptoms occur
because hypocapnia causes reduced cerebral blood
flow (CBF).CBF decreases by 2 for every 1 mm Hg
decrease in PaCO2. - Symptoms of dizziness, weakness, confusion, and
agitation are common . Patients may experience
visual hallucinations, syncope or seizure . - Paresthesias occur more commonly in the upper
extremity and are usually bilateral. Perioral
numbness is very common. - Gastrointestinal symptoms
- (eg, bloating, belching, flatus, or epigastric
pressure) may result from aerophagia.
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38Metabolic changes
- Acute metabolic changes result from intracellular
shifts and increased protein binding of various
electrolytes during respiratory alkalosis. - Acute secondary hypocalcemia can result in
carpopedal spasm, muscle twitching, a prolonged
QT interval, and positive Chvostek and Trousseau
signs. - Hypokalemia tends to be less pronounced than
hypocalcemia but can produce generalized
weakness. - Acute secondary hypophosphatemia is common and
may contribute to paresthesias and generalized
weakness.
39Chvosteks sign is twitching of facial muscles in
response to tapping over the area of the facial
nerve Trousseaus sign is carpopedal spasm that
results from ischemia, such as that induced by
pressure applied to the upper arm from an
inflated sphygmomanometer cuff .
40 Chvosteks sign is neither sensitive nor
specific for hypocalcemia, since it is absent in
about one third of patients with hypocalcemia and
is present in approximately 10 of persons with
normal calcium levels.
- Trousseaus sign is more sensitive and specific
it is present in 94 of patients with
hypo-calcemia and in only 1 of persons with
normal calcium levels.
41Chronic hyperventilation
- The diagnosis of chronic HVS is much more
difficult than that of acute HVS because
hyperventilation is usually not clinically
apparent. Often, these patients have already
undergone extensive medical investigations and
have been assigned several misleading diagnoses. - Two thirds of patients with chronic HVS have a
persistently slightly low PaCO2 with compensatory
renal excretion of bicarbonate, resulting in a
near-normal pH level. - These patients tend to have more prominent CNS
symptoms than patients who maintain normal PaCO2
during attacks. - Usually present with dyspnea and chest pain.
- Frequent sighing respirations (2-3 breaths/min)
and frequent yawning are noted.
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43Chronic hyperventilation
- The respiratory alkalosis can be maintained with
occasional deep sighing respirations, which are
observed often in patients with chronic HVS. - When faced with an additional stress that
provokes hyperventilation, the physiologic
acid-base reserve is less, and these patients
become symptomatic more readily than patients
without HVS. - Dry mouth occurs with mouth breathing and
anxiety. - Many of these patients suffer from
obsessive-compulsive disorders, experience sexual
and marital difficulties, and have poor
adaptations to stress. - Chronic HVS may have symptoms that mimic those of
virtually any serious organic disorder, but they
usually have atypical features of these diseases.
44Differential Diagnoses
- Asthma
- Atrial Fibrillation
- Myocardial Infarction
- Diabetic Ketoacidosis
- Metabolic Acidosis
- Nasopharyngeal Stenosis
- Pneumothorax, Pneumomediastinum
- Pulmonary Embolism
- Respiratory Distress Syndrome, Adult
- Carbon monoxide poisoning
- Panic Disorders
45Approach Considerations
- Upon a first attack of acute HVS, the diagnosis
depends on recognizing the typical constellation
of signs and symptoms and ruling out the serious
conditions that can cause the presenting
symptoms. - Acute coronary syndrome (ACS) and pulmonary
embolism (PE) are the 2 most common serious
entities that may present similarly to HVS. - Clinical assessment is sufficient to rule these
out. More specific testing is sometimes
warranted. - A standard workup for atypical chest pain,
including pulse oximetry, chest radiography, and
ECG, may still be warranted depending on the
clinical picture.
46Approach Considerations
- Patients with a history of HVS who have undergone
an appropriate workup at some earlier time may
not need any further laboratory evaluation in the
setting of a recurrence. Recognition of the
typical constellation of dyspnea, agitation,
dizziness, atypical chest pain, tachypnea and
hyperpnea, paresthesias, and carpopedal spasm in
a young, otherwise healthy patient with an
adequate prior evaluation is sufficient to make
the diagnosis. - A low pulse oximetry reading in a patient who is
hyperventilating should never be attributed to
HVS. The patient should always be evaluated for
other causes of hyperventilation.
47Approach Considerations
- A normal pulse oximetry reading is not helpful,
because a severe defect in gas exchange can
easily be masked by hyperventilation. - A fraction of patients with chronic PE will have
compensated chronic hyperventilation that may
mimic primary chronic hyperventilation. - ABG is indicated if any doubt exists as to the
patients underlying respiratory status it may
be helpful when HVS-induced acidosis is
suspected, or when shunting or impaired pulmonary
gas exchange is considered.
48Approach Considerations
- ABG sampling confirms a compensated respiratory
alkalosis in a majority of cases. The pH is
typically near normal, with a low PaCO2 and a low
bicarbonate level. - ABG sampling is also useful in ruling out
toxicity from carbon monoxide poisoning, which
may present similarly to HVS. - Toxicology screening is indicated.
- If acute PE is being considered, ELISA D-dimer
assay may be helpful.
49Pulse CO-oximeters
- Pulse Co-oximetry measures absorption at several
wavelengths to distinguish the percentage of
oxygenated Hemoglobin compared to the total
amount of hemoglobin (Hb), including
carboxyhemoglobin (carboxy-Hb), Methemoglobin
(met-Hb), oxyhemoglobin (oxy-Hb), and reduced Hb. - When a patient presents with carbon monoxide
poisoning (CO), the pulse CO-oximeter will detect
the levels of each hemoglobin and will report the
oxyhemoglobin saturation as markedly reduced ,
50Pulse CO-oximeters
- Traditionally, this measurement is made from
arterial blood processed in a blood gas analyzer
with a CO-oximeter. - More recently, pulse CO-oximeters have made it
possible to estimate carboxyhemoglobin with
non-invasive technology similar to a Pulse
oximeter. - In contrast, the use of a standard pulse oximeter
is not effective in the diagnosis of CO poisoning
as patients suffering from carbon monoxide
poisoning may have a normal oxygen saturation
reading on a pulse oximeter .
51Approach Considerations
- Imaging studies are not indicated when the
diagnosis of HVS is clear. - Because PE can present with findings identical to
those of HVS, a first-ever episode of acute HVS
may warrant V/Q scanning or CT pulmonary
angiography to rule out perfusion defects. - Chest radiography is indicated for patients who
are at high risk for cardiac or pulmonary
pathology.
52Approach Considerations
- ECG changes are common and may include the
following - 1- ST depression or elevation
- 2- Prolonged QT interval
- 3- T-wave inversion
- 4- Sinus tachycardia
- Rebreathing into a paper bag is not recommended
in the field. Deaths have occurred in patients
with acute myocardial infarction (MI),
pneumothorax, and pulmonary embolism (PE) who
were initially misdiagnosed with HVS and treated
with paper bag rebreathing.
53Rebreathing into a paper bag 1- Have the
hyperventilating person breathe slowly into a
paper bag that's held closely around his or her
mouth and nose. 2- The person should breathe
like this for five to seven minutes. 3-Talk to
the individual the entire time. Try to distract
him or her and make the person feel comfortable
and safe. 4- If symptoms fail to improve or the
person loses consciousness, take him or her to
the emergency room.
54Approach Considerations
- Patients should be referred to a consultant
psychiatrist, psychologist with expertise in
managing HVS. - Some physiotherapists and respiratory therapists
have extensive experience in retraining patients
in proper breathing techniques and should be
consulted.
55Breathing Techniques
- Rebreathing into a paper bag is no longer a
recommended technique, because significant
hypoxia and death have been reported. - Paper bag rebreathing is often unsuccessful in
reversing the symptoms of HVS, because patients
have difficulty complying with the technique.
Moreover, carbon dioxide itself may be a chemical
trigger for anxiety in these patients. - Simple reassurance and an explanation of how
hyperventilation produces the patients symptoms
are usually sufficient to terminate the episode. - Provoking the symptoms by having the patient
voluntarily hyperventilate for 3-4 minutes often
convinces the patient of the diagnosis.
56Breathing Techniques
- Most patients with HVS tend to breathe with the
upper thorax and have hyper-inflated lungs
throughout the respiratory cycle. Because
residual lung volume is high, they are unable to
achieve full tidal volume and experience dyspnea. - Physically compressing the upper thorax and
having patients exhale maximally decreases
hyperinflation of the lungs. - Instructing patients to breathe abdominally,
using the diaphragm more than the chest wall,
often leads to improvement in subjective dyspnea
and eventually corrects many of the associated
symptoms.
57What is calm breathing?
- Calm breathing (sometimes called diaphragmatic
breathing) is a technique that helps you slow
down your breathing when feeling stressed or
anxious. - Newborn babies naturally breathe this way, and
singers, wind instrument players, and yoga
practitioners use this type of breathing. - Diaphragmatic breathing slows the respiratory
rate, gives patients a distracting maneuver to
perform when attacks occur, and provides patients
with a sense of self-control during episodes of
hyperventilation. - This technique has been shown to be very
effective in a high proportion of patients with
HVS.
58Why is calm breathing important?
- Our breathing changes when we are feeling
anxious. We tend to take short , quick, shallow
breaths, or even hyperventilate this is called
overbreathing. - It is a good idea to learn techniques for
managing overbreathing, because this type of
breathing can actually make you feel even more
anxious (e.g., due to a racing heart, dizziness,
or headaches)! - Calm breathing is a great portable tool that
you can use whenever you are feeling anxious.
However, it does require some practice.
59How to Do It?
- Calm breathing involves taking smooth, slow, and
regular breaths. - Sitting upright is usually better than lying down
or slouching, because it can increase the
capacity of your lungs to fill with air. - It is best to 'take the weight' off your
shoulders by supporting your arms on the
side-arms of a chair, or on your lap.
60How to Do It ?
- 1. Take a slow breath in through the nose,
breathing into your lower belly (for about 4
seconds) - 2. Hold your breath for 1 or 2 seconds
- 3. Exhale slowly through the mouth (for about 4
seconds) - 4. Wait a few seconds before taking another
breath - About 6-8 breathing cycles per minute is often
helpful to decrease anxiety, but find your own
comfortable breathing rhythm. - These cycles regulate the amount of oxygen you
take in so that you do not experience the
fainting, tingling, and giddy sensations that are
sometimes associated with overbreathing.
61Helpful Hints
- Make sure that you arent hyperventitating it is
important to pause for a few seconds after each
breath. - Try to breathe from your diaphragm or abdomen.
- Your shoulders and chest area should be fairly
relaxed and still. If this is challenging at
first, it can be helpful to first try this
exercise by lying down on the floor with one hand
on your heart, the other hand on your abdomen.
Watch the hand on your abdomen rise as you fill
your lungs with air, expanding your chest. (The
hand over your heart should barely move, if at
all.)
62Pharmacologic Therapy
- Several medications, including benzodiazepines
and selective serotonin reuptake inhibitors
(SSRIs), have been employed to reduce the
frequency and severity of episodes of
hyperventilation. - These agents require prolonged use and are best
managed by a consultant on an ongoing outpatient
basis rather than through sporadic prescriptions
after an ED visit. - Use of benzodiazepines for stress relief and for
resetting the trigger for hyperventilation is
effective, but again, patients may require
prolonged treatment.
63Pharmacologic Therapy
- Benzodiazepines are useful in the treatment of
hyperventilation resulting from anxiety and panic
attacks. - By binding to specific receptor sites, these
agents appear to potentiate the effects of
gamma-aminobutyric acid (GABA) and to facilitate
inhibitory GABA neurotransmission and the actions
of other inhibitory transmitters. - Alprazolam (xanax) is indicated for treatment of
anxiety and management of panic attacks. - Lorazepam (ativan) is a sedative-hypnotic of the
benzodiazepine class that has a short time to
onset of effect and a relatively long half-life. -
64Pharmacologic Therapy
- Diazepam (valium) depresses all levels of the CNS
(eg, limbic and reticular formation), possibly by
increasing the activity of GABA. It is considered
second-line therapy for seizures. - Paroxetine (paxil) is the alternative drug of
choice for HVS. It is a potent selective
inhibitor of neuronal reuptake of serotonin and
has a weak effect on neuronal reuptake of
norepinephrine and dopamine.
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