NEET MDS Synopsis
Emergency Drugs
Anaesthesia
Emergency Drugs for Sedated Patients (AAPD Guidelines)
In the context of pediatric dentistry and sedation, it is crucial to be prepared
for potential emergencies that may arise during or after sedation. The following
is a list of emergency drugs that may be needed to rescue a sedated patient,
along with their indications and uses.
Emergency Drugs
Albuterol for Inhalation
Indication: Bronchospasm or asthma exacerbation.
Use: Administered via nebulizer or metered-dose inhaler to
relieve bronchospasm.
Ammonia Spirits
Indication: Syncope or fainting.
Use: Inhaled to stimulate respiration and increase alertness.
Atropine
Indication: Bradycardia or asystole.
Use: Increases heart rate by blocking vagal effects on the
heart.
Diazepam
Indication: Seizures or severe anxiety.
Use: Administered intravenously or intramuscularly for rapid
sedation or seizure control.
Diphenhydramine
Indication: Allergic reactions or anaphylaxis.
Use: Antihistamine for allergic symptoms; may also be used for
sedation.
Epinephrine (1:1,000 and 1:10,000)
Indication: Anaphylaxis or severe asthma attack.
Use: 1:1,000 for intramuscular injection; 1:10,000 for
intravenous administration in cardiac arrest.
Flumazenil
Indication: Benzodiazepine overdose.
Use: Reversal agent for sedation caused by benzodiazepines.
Fosphenytoin
Indication: Status epilepticus.
Use: Anticonvulsant for seizure control, administered
intravenously.
Glucose (25% or 50%)
Indication: Hypoglycemia.
Use: Administered intravenously to rapidly increase blood
glucose levels.
Lidocaine
Indication: Cardiac arrhythmias or local anesthesia.
Use: Antiarrhythmic agent for ventricular arrhythmias; also
used for local anesthesia.
Lorazepam
Indication: Anxiety or seizures.
Use: Sedative and anticonvulsant, administered intravenously or
intramuscularly.
Methylprednisolone
Indication: Severe allergic reactions or inflammation.
Use: Corticosteroid for reducing inflammation and managing
allergic reactions.
Naloxone
Indication: Opioid overdose.
Use: Opioid antagonist to reverse respiratory depression and
sedation caused by opioids.
Oxygen
Indication: Hypoxia or respiratory distress.
Use: Administered to improve oxygen saturation and support
respiratory function.
Racemic Epinephrine
Indication: Croup or severe bronchospasm.
Use: Administered via nebulization to reduce airway swelling
and improve breathing.
Rocuronium
Indication: Neuromuscular blockade for intubation.
Use: Non-depolarizing neuromuscular blocker for facilitating
intubation.
Sodium Bicarbonate
Indication: Metabolic acidosis or hyperkalemia.
Use: Administered intravenously to correct acidosis and manage
elevated potassium levels.
Succinylcholine
Indication: Rapid sequence intubation.
Use: Depolarizing neuromuscular blocker for quick intubation.
Antiarrhythmic Drugs-Class II Beta Blockers
Pharmacology
Class II Beta Blockers
Block SNS stimulation of beta receptors in the heart and decreasing risks of ventricular fibrillation
– Blockage of SA and ectopic pacemakers: decreases automaticity
– Blockage of AV increases the refractory period
- Increase AV nodal conduction ´
- Increase PR interval
- Reduce adrenergic activity
Treatment: Supraventricular tachycardia (AF, flutter, paroxysmal supraventricular tachycardia
– Acebutolol
– Esmolol
– Propanolol
Contraindications and Cautions
• Contraindicated in sinus bradycardia P < 45
• Cardiogenic shock, asthma or respiratory depression which could be made worse by the blocking of Beta receptors.
• Use cautiously in patients with diabetes and thyroid dysfunction, which could be altered by the blockade of Beta receptors
• Renal and hepatic dysfunction could alter the metabolism and excretion of these drugs.
The Adrenal Glands
Physiology
The Adrenal Glands
The adrenal glands are two small structures situated one at top each kidney. Both in anatomy and in function, they consist of two distinct regions:
an outer layer, the adrenal cortex, which surrounds
the adrenal medulla.
The Adrenal Cortex
cells of the adrenal cortex secrete a variety of steroid hormones.
glucocorticoids (e.g., cortisol)
mineralocorticoids (e.g., aldosterone)
androgens (e.g., testosterone)
Production of all three classes is triggered by the secretion of ACTH from the anterior lobe of the pituitary.
Glucocorticoids
They Effect by raising the level of blood sugar (glucose). One way they do this is by stimulating gluconeogenesis in the liver: the conversion of fat and protein into intermediate metabolites that are ultimately converted into glucose.
The most abundant glucocorticoid is cortisol (also called hydrocortisone).
Cortisol and the other glucocorticoids also have a potent anti-inflammatory effect on the body. They depress the immune response, especially cell-mediated immune responses.
Mineralocorticoids
The most important of them is the steroid aldosterone. Aldosterone acts on the kidney promoting the reabsorption of sodium ions (Na+) into the blood. Water follows the salt and this helps maintain normal blood pressure.
Aldosterone also
acts on sweat glands to reduce the loss of sodium in perspiration;
acts on taste cells to increase the sensitivity of the taste buds to sources of sodium.
The secretion of aldosterone is stimulated by:
a drop in the level of sodium ions in the blood;
a rise in the level of potassium ions in the blood;
angiotensin II
ACTH (as is that of cortisol)
Androgens
The adrenal cortex secretes precursors to androgens such as testosterone.
Excessive production of adrenal androgens can cause premature puberty in young boys.
In females, the adrenal cortex is a major source of androgens. Their hypersecretion may produce a masculine pattern of body hair and cessation of menstruation.
Addison's Disease: Hyposecretion of the adrenal cortices
Addison's disease has many causes, such as
destruction of the adrenal glands by infection;
their destruction by an autoimmune attack;
an inherited mutation in the ACTH receptor on adrenal cells.
Cushing's Syndrome: Excessive levels of glucocorticoids
In Cushing's syndrome, the level of adrenal hormones, especially of the glucocorticoids, is too high.It can be caused by:
excessive production of ACTH by the anterior lobe of the pituitary;
excessive production of adrenal hormones themselves (e.g., because of a tumor), or (quite commonly)
as a result of glucocorticoid therapy for some other disorder such as
rheumatoid arthritis or
preventing the rejection of an organ transplant.
The Adrenal Medulla
The adrenal medulla consists of masses of neurons that are part of the sympathetic branch of the autonomic nervous system. Instead of releasing their neurotransmitters at a synapse, these neurons release them into the blood. Thus, although part of the nervous system, the adrenal medulla functions as an endocrine gland.The adrenal medulla releases:
adrenaline (also called epinephrine) and
noradrenaline (also called norepinephrine)
Both are derived from the amino acid tyrosine.
Release of adrenaline and noradrenaline is triggered by nervous stimulation in response to physical or mental stress. The hormones bind to adrenergic receptors transmembrane proteins in the plasma membrane of many cell types.
Some of the effects are:
increase in the rate and strength of the heartbeat resulting in increased blood pressure;
blood shunted from the skin and viscera to the skeletal muscles, coronary arteries, liver, and brain;
rise in blood sugar;
increased metabolic rate;
bronchi dilate;
pupils dilate;
hair stands on end (gooseflesh in humans);
clotting time of the blood is reduced;
increased ACTH secretion from the anterior lobe of the pituitary.
All of these effects prepare the body to take immediate and vigorous action.
Orthodontic Force
OrthodonticsOrthodontic Force Duration
Continuous Forces:
Definition: Continuous forces are applied
consistently over time without interruption.
Application: Many extraoral appliances, such as
headgear, are designed to provide continuous force to the teeth and
jaws. This type of force is essential for effective tooth movement and
skeletal changes.
Example: A headgear may be worn for 12-14 hours a
day to achieve the desired effects on the maxilla or mandible.
Intermittent Forces:
Definition: Intermittent forces are applied in a
pulsed or periodic manner, with breaks in between.
Application: Some extraoral appliances may use
intermittent forces, but this is less common. Intermittent forces can be
effective in certain situations, but continuous forces are generally
preferred for consistent tooth movement.
Example: A patient may be instructed to wear an
appliance for a few hours each day, but this is less typical for
extraoral devices.
Force Levels
Light Forces:
Definition: Light forces are typically in the range
of 50-100 grams and are used to achieve gentle tooth movement.
Application: Light forces are ideal for orthodontic
treatment as they minimize discomfort and reduce the risk of damaging
the periodontal tissues.
Example: Some extraoral appliances may be designed
to apply light forces to encourage gradual movement of the teeth or to
modify jaw relationships.
Moderate Forces:
Definition: Moderate forces range from 100-200
grams and can be used for more significant tooth movement or skeletal
changes.
Application: These forces can be effective in
achieving desired movements but may require careful monitoring to avoid
discomfort or adverse effects.
Example: Headgear that applies moderate forces to
the maxilla to correct Class II malocclusions.
Heavy Forces:
Definition: Heavy forces exceed 200 grams and are
typically used for rapid tooth movement or significant skeletal changes.
Application: While heavy forces can lead to faster
results, they also carry a higher risk of complications, such as root
resorption or damage to the periodontal ligament.
Example: Some extraoral appliances may apply heavy
forces for short periods, but this is generally not recommended for
prolonged use.
Le Fort Fractures
Oral and Maxillofacial SurgeryLe Fort I Fracture
A horizontal fracture that separates the maxilla from the nasal and
zygomatic bones. It is also known as a "floating maxilla."
Signs and Symptoms:
Bilateral Periorbital Edema and Ecchymosis: Swelling
and bruising around the eyes (Raccoon eyes).
Disturbed Occlusion: Malocclusion due to displacement
of the maxilla.
Mobility of the Maxilla: The maxilla may move
independently of the rest of the facial skeleton.
Nasal Bleeding: Possible epistaxis due to injury to the
nasal mucosa.
CSF Rhinorrhea: If there is a breach in the dura mater,
cerebrospinal fluid may leak from the nose.
Le Fort II Fracture
A pyramidal fracture that involves the maxilla, nasal bones, and the
zygomatic bones. It is characterized by a fracture line that extends from
the nasal bridge to the maxilla and zygomatic arch.
Signs and Symptoms:
Bilateral Periorbital Edema and Ecchymosis: Swelling
and bruising around the eyes (Raccoon eyes).
Diplopia: Double vision due to involvement of the
orbital floor and potential muscle entrapment.
Enophthalmos: Posterior displacement of the eyeball
within the orbit.
Restriction of Globe Movements: Limited eye movement
due to muscle entrapment.
Disturbed Occlusion: Malocclusion due to displacement
of the maxilla.
Nasal Bleeding: Possible epistaxis.
CSF Rhinorrhea: If the dura is torn, cerebrospinal
fluid may leak from the nose.
Le Fort III Fracture
A craniofacial disjunction fracture that involves the maxilla, zygomatic
bones, and the orbits. It is characterized by a fracture line that separates
the entire midface from the skull base.
Signs and Symptoms:
Bilateral Periorbital Edema and Ecchymosis: Swelling
and bruising around the eyes (Raccoon eyes).
Orbital Dystopia: Abnormal positioning of the orbits,
often with an antimongoloid slant.
Diplopia: Double vision due to muscle entrapment or
damage.
Enophthalmos: Posterior displacement of the eyeball.
Restriction of Globe Movements: Limited eye movement
due to muscle entrapment.
Disturbed Occlusion: Significant malocclusion due to
extensive displacement of facial structures.
CSF Rhinorrhea: If there is a breach in the dura mater,
cerebrospinal fluid may leak from the nose or ears (CSF otorrhea).
Bleeding Over Mastoid Process (Battle’s Sign): Bruising
behind the ear may indicate a skull base fracture.
The Medial Wall of the Orbit
AnatomyThe Medial Wall of the Orbit
This wall is paper-thin and is formed by the orbital lamina or lamina papyracea of the ethmoid bone, along with contributions from the frontal, lacrimal, and sphenoid bones (L. papyraceus, "made of papyrus" or parchment paper).
There is a vertical lacrimal groove in the medial wall, which is formed anteriorly by the maxilla and posteriorly by the lacrimal bone.
It forms a fossa for the lacrimal sac and the adjacent part of the nasolacrimal duct.
Along the suture between the ethmoid and frontal bones are two small foramina; the anterior and posterior ethmoidal foramina.
These transmit nerves and vessels of the same name.
Ludwig's Angina
Oral and Maxillofacial SurgeryLudwig's Angina
Ludwig's angina is a serious, potentially life-threatening
cellulitis or connective tissue infection of the submandibular space. It is
characterized by bilateral swelling of the submandibular and sublingual areas,
which can lead to airway obstruction. The condition is named after the German
physician Wilhelm Friedrich Ludwig, who provided a classic
description of the disease in the early 19th century.
Historical Background
Coining of the Term: The term "Ludwig's angina" was
first coined by Camerer in 1837, who
presented cases that included a classic description of the condition. The
name honors W.F. Ludwig, who had described the features of
the disease in the previous year.
Etymology:
The word "angina" is derived from the Latin word "angere," which
means "to suffocate" or "to choke." This reflects the potential for
airway compromise associated with the condition.
The name "Ludwig" recognizes the contributions of
Wilhelm Friedrich Ludwig to the understanding of this medical entity.
Ludwig's Personal Connection: Interestingly, Ludwig
himself died of throat inflammation in 1865, which
underscores the severity of infections in the head and neck region.
Clinical Features
Ludwig's angina typically presents with the following features:
Bilateral Swelling: The most characteristic sign is
bilateral swelling of the submandibular area, which can extend to the
sublingual space. This swelling may cause the floor of the mouth to elevate.
Pain and Tenderness: Patients often experience pain and
tenderness in the affected area, which may worsen with movement or
swallowing.
Dysphagia and Dysarthria: Difficulty swallowing
(dysphagia) and changes in speech (dysarthria) may occur due to swelling and
discomfort.
Airway Compromise: As the swelling progresses, there is
a risk of airway obstruction, which can be life-threatening. Patients may
exhibit signs of respiratory distress.
Systemic Symptoms: Fever, malaise, and other systemic
signs of infection may be present.
Etiology
Ludwig's angina is most commonly caused by infections that originate from the
teeth, particularly the second or third molars. The infection can spread from
dental abscesses or periodontal disease into the submandibular space. The most
common pathogens include:
Streptococcus species
Staphylococcus aureus
Anaerobic bacteria
Diagnosis and Management
Diagnosis: Diagnosis is primarily clinical, based on the
characteristic signs and symptoms. Imaging studies, such as CT scans, may be
used to assess the extent of the infection and to rule out other conditions.
Management:
Airway Management: Ensuring a patent airway is the
top priority, especially if there are signs of respiratory distress.
Antibiotic Therapy: Broad-spectrum intravenous
antibiotics are initiated to target the likely pathogens.
Surgical Intervention: In cases of significant
swelling or abscess formation, surgical drainage may be necessary to
relieve pressure and remove infected material.
Bias in Public Health Dentistry
Public Health DentistryHere are some common types of bias encountered in public health dentistry,
along with their implications:
1. Selection Bias
Description: This occurs when the individuals included in a
study are not representative of the larger population. This can happen due to
non-random sampling methods or when certain groups are more likely to be
included than others.
Implications:
If a study on dental care access only includes patients from a specific
clinic, the results may not be generalizable to the broader community.
Selection bias can lead to over- or underestimation of the prevalence of
dental diseases or the effectiveness of interventions.
2. Information Bias
Description: This type of bias arises from inaccuracies in
the data collected, whether through measurement errors, misclassification, or
recall bias.
Implications:
Recall Bias: Patients may not accurately remember their
dental history or behaviors, leading to incorrect data. For example,
individuals may underestimate their sugar intake when reporting dietary
habits.
Misclassification: If dental conditions are
misdiagnosed or misreported, it can skew the results of a study assessing
the effectiveness of a treatment.
3. Observer Bias
Description: This occurs when the researcher’s expectations
or knowledge influence the data collection or interpretation process.
Implications:
If a dentist conducting a study on a new treatment is aware of which
patients received the treatment versus a placebo, their assessment of
outcomes may be biased.
Observer bias can lead to inflated estimates of treatment effectiveness
or misinterpretation of results.
4. Confounding Bias
Description: Confounding occurs when an outside variable is
associated with both the exposure and the outcome, leading to a false
association between them.
Implications:
For example, if a study finds that individuals with poor oral hygiene
have higher rates of cardiovascular disease, it may be confounded by
lifestyle factors such as smoking or diet, which are related to both oral
health and cardiovascular health.
Failing to control for confounding variables can lead to misleading
conclusions about the relationship between dental practices and health
outcomes.
5. Publication Bias
Description: This bias occurs when studies with positive or
significant results are more likely to be published than those with negative or
inconclusive results.
Implications:
If only studies showing the effectiveness of a new dental intervention
are published, the overall understanding of its efficacy may be skewed.
Publication bias can lead to an overestimation of the benefits of
certain treatments or interventions in the literature.
6. Survivorship Bias
Description: This bias occurs when only those who have
"survived" a particular process are considered, ignoring those who did not.
Implications:
In dental research, if a study only includes patients who completed a
treatment program, it may overlook those who dropped out due to adverse
effects or lack of effectiveness, leading to an overly positive assessment
of the treatment.
7. Attrition Bias
Description: This occurs when participants drop out of a
study over time, and the reasons for their dropout are related to the treatment
or outcome.
Implications:
If patients with poor outcomes are more likely to drop out of a study
evaluating a dental intervention, the final results may show a more
favorable outcome than is truly the case.
Addressing Bias in Public Health Dentistry
To minimize bias in public health dentistry research, several strategies can
be employed:
Random Sampling: Use random sampling methods to ensure
that the sample is representative of the population.
Blinding: Implement blinding techniques to reduce
observer bias, where researchers and participants are unaware of group
assignments.
Standardized Data Collection: Use standardized
protocols for data collection to minimize information bias.
Statistical Control: Employ statistical methods to
control for confounding variables in the analysis.
Transparency in Reporting: Encourage the publication of
all research findings, regardless of the results, to combat publication
bias.