Índice Gestión Municipal
MECANISMOS DE ARTICULACIÓN MUNICIPAL Municipalidad
Sajeesh Kuriakose
Today both practitioners and the public are better educated about pain and anxiety control. In patients who are fit and healthy, conscious sedation is seen as a benefit for long procedures, difficult procedures and for the disproportionately anxious patients. Some patients just want a high level of comfort for treatment.
Conscious sedation is a powerful tool. Many patients who previously relied on general anesthesia are learning to cope and accept treatment with conscious sedation. As a profession we are informing our patients better and providing quality written information. Both practitioners and patients are taking on their responsibilities at a level that was inconceivable possibly even a decade ago. Anecdotally there is increasing demand, but high-quality evidence for this is becoming increasingly available. The need for conscious sedation in Oral and Maxillofacial surgery is high.
Conscious sedation is very safe. To maintain the highest standards, education needs to improve but the profession can be proud of leading the field in this respect. Safe conscious sedation has been available to Maxillofacial surgeons and more importantly their patients for many years. A renaissance in attitudes to pain and anxiety control throughout the medical profession is beginning to highlight the importance of conscious sedation for our patients. The challenge is improved educational pathways for the benefit of patients’ safe, gentle and comfortable care.
SAFETY FIRST
SAFETY FIRST
SAFETY FIRST
SAFETY FIRST
SAFETY FIRST
As a profession we have a lot of indications for using conscious sedation. The question commonly asked is whether it is dangerous? Most sedative drugs are anes- thetic drugs used in a different way, therefore a badly used sedative could result in uncontrolled anesthesia. Without doubt, uncontrolled anesthesia puts patients at potential risk.
The profession has an enviable record in safety in conscious sedation, with mortality of only a handful in millions of administrations in the last two decades. Conversely, mortality in other medical specialities, particularly endoscopy, has been as high as 1 in 2,500. Even when one accounts for the higher risk patients and other contributing factors, the mortality and morbidity associated with the sedation must be seriously questioned. Each speciality has specific challenges that need to be addressed by that speciality alone.
The safety of a sedative procedure relates to proper patient selection, technique selection, the training and experience of the sedationist and associated maxillofacial team and an appropriate environment in which to carry it out.
WHA
WHA
WHA
WHA
WHAT IS CONSCIOUS SEDT IS CONSCIOUS SEDT IS CONSCIOUS SEDT IS CONSCIOUS SEDT IS CONSCIOUS SEDAAAAATION?TION?TION?TION?TION?
Conscious sedation is defined as the administration of pharmacological agents to produce a medically controlled state of depressed consciousness that:
• Allows protective reflexes to be maintained; • Retains the patient’s ability to maintain a patent airway
independently and continuously;
• Permits appropriate responses by the patient. Unconscious sedation is sedation associated with loss of protective reflexes.
The goals of procedural sedation are to provide anal- gesia, amnesia, and anxiolysis during a potentially painful or frightening procedure. Patients who receive conscious sedation usually are able to speak and respond to verbal cues throughout the procedure, communicating any discomfort they experience to the provider. A brief period of amnesia may erase any memory of the procedure.
FIGURE 7.1: The goals of conscious sedation are to provide analgesia, amnesia, and anxiolysis during a potentially painful or frightening procedure
TYPES OF SED
TYPES OF SED
TYPES OF SED
TYPES OF SED
TYPES OF SEDAAAATION ADMINISTRAATION ADMINISTRATION ADMINISTRATION ADMINISTRATIONTION ADMINISTRATIONTIONTIONTION
• Enteral: Any technique of administration in which the agent is absorbed through the gastrointestinal tract or oral mucosa (i.e., oral, rectal, and sublingual). • Parenteral: A technique of administration in which
the drug bypasses the gastrointestinal tract (i.e., intramuscular, intravenous, intranasal, submucosal, subcutaneous, and intraocular).
• Transdermal/transmucosal: A technique of administration in which the drug is administered by patch or iontophoresis.
• Inhalation: A technique of administration in which a gaseous or volatile agent is introduced into the pulmonary tree and whose primary effect is due to absorption through the pulmonary bed.
Enter
Enter
Enter
Enter
Enteral Conscious Sedation (ECS)al Conscious Sedation (ECS)al Conscious Sedation (ECS)al Conscious Sedation (ECS)al Conscious Sedation (ECS)
Enteral conscious sedation is primarily used to curb anxiety and fear in a patient without rendering them unconscious. Dentists use ECS in 10 percent of cases in the US, in procedures ranging from prophylaxis to fillings and surgeries.
Prior to the 1960s, alcohol and barbiturates were used to relax patients. Once benzodiazepines hit the market, they became the drugs of choice for dentists. Triazolam is the benzodiazepine most commonly used by dentists because of its rapid onset, reported high margin of safety, and the availability of the antagonist flumazenil. Triazolam’s popularity with dentists also stems from the drug’s short half-life and duration. Peak plasma concentration of 0.25 mg to 0.50 mg occurs in about one hour. The elimination half-time is 1.7 hours. “The combination of probable amnesia and somnolence has brought triazolam into the forefront as a preferred sedative among dentists who use oral sedation in their practice,” according to a 2002 study reported in “The Dental Clinics of North America”, titled “Inhalation and enteral conscious sedation for the adult dental patient.”
IV or inhalation sedation is more ideally suited to titration because the effect upon the patient is immediate. “It gets into body quickly. The dentists can measure the effect and give more if necessary. With oral conscious sedation the effect would take an hour or two. It might take all day to titrate appropriately.” The slow absorption makes it more difficult for dentists to assess whether or not they over-sedated the patient.
“The major drawback of oral sedation is that absorption rates are highly variable. Nitrous oxide goes right to the lungs. IV is delivered straight into the bloodstream—it doesn’t have to go thorough a process.” The absorption process for ECS can vary depending on the amount of food in the patient’s stomach and the other medication they are taking.
Drugs Used for Oral Sedation
1. Diazepam (Valium), 0.2 to 0.3 mg/kg, maximum to 10 mg, orally 45 to 60 minutes before procedure 2. Chloral hydrate, 75 to 100 mg/kg, maximum to
Intr
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Intraaaaavvvvvenous Conscious Sedationenous Conscious Sedationenous Conscious Sedationenous Conscious Sedationenous Conscious Sedation
Intravenous conscious sedation (IVCS) is a minimally depressed level of consciousness that retains the patient’s ability to maintain a patent airway independently and continuously and respond appropriately to physical stimulation and verbal commands. IVCS may be administered during therapeutic, diagnostic or surgical procedures. The drugs, dosages and techniques utilized for IVCS are not intended to produce loss of conscious- ness. Conscious sedation should be distinguished from two other levels of consciousness: deep sedation and general anesthesia. Deep sedation is a controlled state of depressed consciousness or unconsciousness from which the patient is not easily aroused, accompanied by a partial or complete loss of protective reflexes, including the ability to maintain a patent airway independently and respond purposefully to physical stimulation or verbal command. General anesthesia is a controlled state of unconsciousness accompanied by a loss of protective reflexes, including loss of the ability to maintain a patent airway or to respond purposefully to physical stimulation or verbal command.
In actuality, a continuum exists among conscious seda- tion, deep sedation and general anesthesia. The patient’s age and preexisting medical conditions may significantly
alter the dosing requirements needed for IVCS. If either deep sedation or general anesthesia is required for the procedure, skilled anesthesia personnel should be available to assist in the management of the patient.
Local anesthetics are used to control regional pain. Sedative drugs and techniques may control fear and anxiety, but do not by themselves fully control pain and, thus, are commonly used in conjunction with local anesthetics. General anesthesia provides complete relief from both anxiety and pain.
Definitions
In order to know how sedated the patient is, one must be familiar with a few definitions. Practicing within the confines of conscious sedation mandates that your patient does not become too sedated. A few important definitions are listed below:
Light sedation
the administration of medications for the reduction of anxiety. In this stage the following should be present: 1. Normal respirations
2. Normal eye movements; and 3. Intact protective reflexes.
Amnesia may or may not be present. The patient is technically awake, but under the influence of the drug administered.
If a patient becomes difficult to arouse or looses ability to maintain a continuously patent airway sponta- neously, then they have gone past conscious sedation to deep sedation.
Conscious sedation (Fig. 7.3)
A medically controlled state of depressed consciousness that
1. Allows protective reflexes to be maintained; 2. Retains the patient’s ability to maintain a patent airway
independently and continuously; and
3. Permits appropriate response by the patient to physical stimulation or verbal command, for example, “open your eyes.”
The drugs, doses, and techniques used are not intended to produce a loss of consciousness. The author use the terms “sedation/analgesia” synonymously with “conscious sedation”
FIGURE 7.2: Intravenous Conscious Sedation (IVCS) is a minimally depressed level of consciousness that retains the patient’s ability to maintain a patent airway independently and continuously and respond appropriately to physical stimulation and verbal commands
Deep sedation
A medically controlled state of depressed consciousness or unconsciousness from which the patient is not easily aroused. It may be accompanied by a partial or complete loss of protective reflexes, and includes the inability to maintain a patent airway independently and respond purposefully to physical stimulation or verbal command. General Anesthesia is a controlled state of uncon- sciousness accompanied by a loss of protective reflexes, including loss of the ability to maintain a patent airway independently or to respond purposefully to physical stimulation or verbal command.
Signs of Sedation
The patient may take a few deeper breaths; the speech (e.g. counting backwards) becomes slower, softer, slurred, cognitive errors occur, and speech ceases; the face assumes a more relaxed appearance and facial tone sags, breathing becomes more shallow and slow; if airway is not supported, the lips may splutter with expirations; the
patient no longer flutters eyelids when the lashes are gently stroked with a finger; the patient no longer responds to a noxious stimulus. The patient should still maintain his respiration and vital signs should be adequate and stable. Awakening occurs in reverse order. Amnesia is neither immediate nor invariable.
Patient Selection
Sedation-related risk factors include significant medical conditions, such as extremes of age; severe pulmonary, cardiac, renal or hepatic disease; pregnancy; the abuse of drugs or alcohol; uncooperative patients; or a potentially difficult airway for intubation. The American Society of Anesthesiologists (ASA) Taskforce states that airway management may be difficult in the following situations:
1. Patients with previous problems with anesthesia or sedation.
2. Patients with a history of stridor, snoring, or sleep apnea.
3. Patients with dysmorphic facial features- such as Pierre-Robin syndrome or trisomy-21.
FIGURE 7.3: Levels of conscious sedation Level of Sedation None “Light” “Moderate” “Deep” General Anesthesia Level of Consciousness
Fully aware of self and surroundings Mostly aware of self and
surrounding, but sedate Slightly aware of self and
surroundings, usually somnolent, arouses
easily with stimuli Not aware of self or
surroundings, little arousal with stimuli Uncoscious, no arousal
with painful stimuli
Response- Verbal P P-L L-A A A Response- Tactile P P P-L L (to pain A (to pain) Sedation Score 0 1 2 3 4 Airway Patency P P P-L § L-A L-A Ventilation, Oxygenation P P P-L • L L-A
P: Present, adequate, or normal L: Limited, partial, mildly abnormal A: Absent, inadequate
*: May need supplemental oxygen to keep SAO2 > 90% §: Airway may need limited support
4. Patients with oral abnormalities -such as a small opening (<3 cm in an adult), edentulous patients, protruding incisors, loose or capped teeth, high arched palate, macroglossia, tonsillar hypertrophy, or a non- visible uvula.
5. Patients with neck abnormalities—such as obesity involving the neck and facial structures, short neck, limited neck extension, decreased hyoid-mental distance (<3 cm in an adult), neck mass, cervical spine disease or trauma, tracheal deviation, or advanced rheumatoid arthritis.
6. Patients with jaw abnormalities- such as micrognathia, retrognathia, trismus, or significant malocclusion. Patients should be triaged to the appropriate ASA Physical Status Classification before conscious sedation is performed.
ASA Classification
• ASA I: Normally healthy
• ASA II: Patient with mild systemic disease (e.g. hyper- tension)
• ASA III: Patient with severe systemic disease (e.g. CHF), non-decompensated
• ASA IV: Patient with severe systemic disease, decom- pensated
• ASA V: Moribund patient, survival unlikely
Additional consideration should be given to those candidates who are over 65 years of age. Dose increments should be smaller and the rate of injection slower, as the bioavailability of benzodiazepines, as with most drugs, changes dramatically with age. This is especially so with the patient who has been pre-medicated with opioids. Additional precautions
• Use of supplemental oxygen by nasal prongs • Use of pulse oximetry. The alarms should be set very
close to the room air saturation of the individual patient.
• Constant one-on-one supervision, especially in a patient who has other health problems. Particular care should be exercised regarding the respiratory rate and verbal responsiveness.
• Appropriate airway and resuscitation equipment and the competency to utilize the same.
Consulting the anesthesiologist: Consultation with the anesthesia department is mandatory before providing conscious sedation in the following situations:
1. Sleep apnea. 2. Extremes of age. 3. Pregnancy.
4. Patients with severe cardiac, pulmonary, hepatic, renal or CNS disease.
5. Drug or alcohol abuse. 6. Morbid obesity.
7. Emergency/unprepared patients. 8. Metabolic and airway difficulties. 9. Patients requiring deep sedation. 10. Uncooperative patients.
Furthermore, anesthesiologist must be consulted immediately in situations where the patient is observed to have lost protective reflexes.
Equipment: Appropriate emergency equipment for maintaining the patient’s airway, ventilatory status and cardiac status should be readily available when sedation/ analgesia medications are given to the patient. Equipment must be suitable for the size and age of the patient. The following equipment is essential, but not limited to: • Emergency cart with defibrillator (Fig. 7.4) imme-
diately accessible • Suction at bedside
• Oxygen and oxygen delivery devices (cannula, mask) • Appropriate oral and nasal airways (pediatric and
adult as appropriate)
• Continuous noninvasive BP monitoring device • Cardiac monitor
• Pulse oximeter • Ambu bag • Intubation tray
• Reversal agents (naloxone and flumazenil) • IV supplies
Medication combinations for conscious sedation: 1. Ketamine, atropine (or glycopyrrolate), and benzo-
diazepine.
2. Benzodiazepine and analgesic.
3. Systemic agents (propofol or etomidate) and analgesic.
Patient Monitoring
The conscious sedation protocol mandates monitoring of blood pressure, pulse, respiratory rate, level of consciousness and blood oxygen saturation at least every 5 minutes. It will be assumed that the reader is familiar with most of these devices, since a prerequisite to providing conscious sedation includes education in these matters. This section will focus on how these devices function and discuss their limitations.
Visual assessments: Before discussing the mechanical monitoring devices, it is important emphasize that the most important monitoring device is the skill of the clinician. Where monitors can fail, a finger on the pulse can tell something about rate, rhythm and strength of cardiac pulsations. The “ABCs” of basic life support should not be forgotten when high-tech monitors are used: Does the patient have a patent airway? Are they breathing? Do they have adequate circulation? With this in mind, we will discuss how the more technical monitors work.
Pulse: Heart rate can be measured in multiple ways: 1. Electrocardiogram: The ECG provides information on
the cardiac conductivity of the heart, but does not indicate what pulse is generated from that activity. In most instances the pulse rate matches the ECG rate, and is usually an accurate indicator of pulse rate.
In situations where the ECG is showing a regular heart rate, but no pulse is generated (and therefore no blood pressure), an electromechanical dissociation is said to occur, and ACLS protocols should be initiated. Continuous ECG monitoring can also give early indication of arrhythmias associated with hypoxia or coexisting disease (Fig. 7.5 and 7.6).
FIGURE 7.5: Normal Electrocardiogram
FIGURE 7.6: Continuous ECG monitoring can also give early indication of arrhythmias associated with hypoxia or coexisting disease.
2. Direct measurements: The pulse oximeter and blood pressure cuff require a pulse for reading, and are reliable indicators of the patient’s pulse. Best assessments of the quality of the pulse are measured through direct palpation or auscultation, and when a question of the patient’s pulse arise, these methods should be used immediately.
3. Pulse oximetry: Studies have proven that respiratory events occur frequently during and shortly after conscious sedation, and that far more of these are recognized when pulse oximetry is continuously used. Indeed, pulse oximetry is the standard of care in anesthesia (Fig. 7.7).
FIGURE 7.7: Pulse oximeter
How it works: The absorption of light passing through a sample of hemoglobin is a logarithmic function of its oxygen saturation. Two wavelengths of light are typically used to distinguish oxyhemoglobin from reduced hemoglobin, 660 nm and 940 nm. This technology is called spectrophotometry. In addition, pulse oxymeters use plethysmography to distinguish between arterial, pulsating blood and venous, nonpulsatile blood. Limitations of pulse oximetry
Pulse oximetry (SpO2) will differ from arterial oxygen
saturation (SaO2) in a few situations; when there is a significant amount of carboxyhemoglobin or methemo- globin in the blood, when the oxygen saturation falls off of the steep part of the oxyhemoglobin dissociation curve (SaO2 less than 70%), or when there is a substance in the blood that absorbs light in the red or infrared spectrum, such as methylene blue.
The pulse oximeter has other limitations as well. Hypotension, hypothermia or the use of vasoconstricting drugs may reduce the pulsatile flow. Ambient light may interfere and cause incorrect readings. Motion of a finger probe may cause failure. The pulse oximeter detects adequacy of oxygenation, but fails to detect adequacy of ventilation (carbon dioxide exchange), and may miss a significant amount of hypoventilation. With these limitations in mind, however, pulse oximetry provides valuable and early information during procedures using sedation and analgesia.
Automated blood pressure cuffs: Automated non-invasive measurements of blood pressure frequently use the technology of oscillometry (Fig. 7.8). This technology is felt to be a reliable representation of true arterial blood pressure. With this technology the points of maximal fluctuations in cuff pressure are sensed while the cuff is deflated. In a typical microprocessor-controlled oscillotonometer the cuff is inflated with an air pump and the pressure is held constant while a sample of oscillations is gathered. If no oscillations are detected, some of the pressure is relieved and another sample is gathered. This is repeated in a step-wise fashion, and algorithms are used to filter artifact.
Cuff size: Proper cuff size and fit are required for adequate measurement (Fig. 7.9). Falsely low estimates will be generated if the cuff is too large, and falsely high estimates will be generated if the cuff is too small. The cuff is considered the proper size when the bladder width is approximately 40 percent of the circumference of the extremity and the bladder length is sufficient to encircle at least 60 percent of the extremity.
FIGURE 7.9: Proper cuff size and fit are required for adequate measurement
Procedure
Using Ketamine, atropine and a benzodiazepine • This is an excellent combination for children under