Random Flashcards
Calculation of BP in different sites (example the arm cuff, and asking what’s the brain pressure?)
The difference in blood pressure at 2 different sites equals the height difference in cm (between cuff pressure and desired pressure sure) multiplied times the conversion factor 0.74.
TrueLearn Insight : A mnemonic to help remember which comes first (pressure or height) is “pH” or “pH 15 20”, where a pressure of 15 mmHg correlates to a height of 20 cm.
Pulse ox reading differences between CO vs methemoglobinmia?
The both would increase PaO2 with supplemental oxygen. However, in contrast, a patient with CO poisoning would most likely have a pulse-ox that is falsely elevated to 100% even while breathing room air since carboxyhemoglobin resembles oxyhemoglobin to a standard pulse oximeter. With methemoglobinmia the pulse ox would read 85-88%
What exacerbates acute intermittent porphyria?
P450 inducers Barbiturates BZDs Nifedipine Glucocorticoids Acute alcohol
These patient should be kept normothermic and well hydrated.
What electrolyte dearrangement must be corrected in anesthesia transplanted liver who is reviving massive blood transfusion?
Hypocalcimia
Citrate toxicity causes ionized hypocalcemia, manifested as hypotension and decreased pulse pressure, QT prolongation, and potential for arrhythmias.
Citrate toxicity causing severe hypocalcemia during liver transplantation is well documented and is manifested as hypotension, narrow pulse pressure, increased intraventricular end-diastolic pressure, and increased central venous pressure
What anti-depressant medication would be relative C/I to use methylene blue and why?
SSRI/SNRI or MaO inhibitors
Methylene blue is a MAO-A inhibitor and may cause serotonin syndrome in patients taking antidepressants. Suggestive symptoms include postoperative delirium and postoperative fever. Treatment is mostly supportive although cyproheptadine, a serotonin receptor antagonist, can be attempted.
what medications used to prevent epistaxis in nasal intubation? Local anesthetic is a choice?
vasoconstrictors such as oxymetazoline and phenylephrine
Lidocaine ointment is helpful in treating the pain of a nasotracheal intubation as well as functioning as a lubricant, particularly in awake intubations. however, does not prevent epistaxis. The only local anesthetic that would be useful for reducing epistaxis in this setting would be cocaine but it carries the risk of inducing arrhythmias.
Airway edema classified to subglottic vs supraglotic, what are the causes of either?
Supraglottic edema most often occurs following surgical instrumentation, secondary to impaired venous drainage (head down or prone position), the formation of a hematoma, excessive fluid administration, or due to coexisting conditions (preeclampsia/eclampsia, angioedema).
Subglottic edema most often occurs following traumatic intubation attempts or due to damage from the endotracheal tube (prolonged intubation, excessive cuff pressure, tight-fitting tube, patient bucking on the ETT).
Subglottic edema is much more common in children due to the smaller diameter of their airway.
Time expected to see post-extubation laryngeal edema ?
usually presents within 30-60 minutes of extubation as stridor although it can present up to 6 hours post-extubation.
Mgmt of post-extubation laryngeal edema?
1) 100% oxygen + head elevation to help improve venous drainage
2) asses for emergent re-intubation
3) nebulized racemic epinephrine
4) Heliox.
Steroids remain controversial and need several hours for effect.
Hoe nebolizer epi and heliox benefits in laryngeal edema?
- nebulized racemic epinephrine: alpha-adrenergic receptor stimulation in the airway resulting in mucosal vasoconstriction, causing a decrease in the amount of fluid present in the airway. It will also cause beta-adrenergic stimulation in the bronchial tissue resulting in bronchodilation, which will not alleviate the edema but can help any component of bronchoconstriction present)
- Heliox: ( it develops less resistance “because of its light density” when passing through the stenosis/edema resulting in less patient effort needed to get the same volume of gas.
RF of pulmonary artery rupture during PAC placement?
hypothermia (it increases catheter stiffness), anticoagulation, old age, and pulmonary hypertension
Compliacations of pulmonary artery placement (PAC)?
arrhythmia, valve damage, infection, PA rupture or infarction, thromboembolism, endocardial damage and misinterpretation of data
Interestingly the risk of endocarditis increase two-fold with use of non-heparin coated PACs.
stimulation of bronchoconstriction via 3 mechanisms?
- Main by parasympathetic nervous system (muscurinic receprots) via the vagus nerve. “ hypoxia & HTN can stimulate vagus nerve through carotid sinue/body to central nucleus ambiguous)
- Alpha receptor stimulation
- Excitation of NANC neurons by substence P & neurokinin A
Most common cause of perioperative retinal arterial occlusion is ?
Improper patient positioning resulting in external compression of the eye.
Postop visual loss due to ischemia of —– optic in cardiac vs spine surgeries?
Cardiac procedures, anterior ischemic optic neuropathy while spine surgery in the prone position, posterior ischemic optic neuropathy seems to be the predominant cause.
An easy way to remember ION would be the location of the surgery predicts the type – posterior spine surgeries = posterior ION and anterior cardiac procedures = anterior ION.
cardiac cases, related to emboli, thrombotic events, ischemic reasons, or even due to oncotic pressure changes.
In spine surgery the risk seems to be related to ischemia and/or patient position.
What pressure changes to PIP & Pplateau with Airway Resistance? DDX?
Increased PIP, Unchanged Pplateau
- Airway compression
- Bronchospasm
- Foreign body
- Kinked endotracheal tube
- Mucus plug
- Secretions
What pressure changes to PIP & Pplateau with Pulmonary Compliance (Elastic Resistance)? DDX?
Both increase( Increased PIP, Increased Pplateau)
- Abdominal insufflation
- Ascites
- Intrinsic lung disease
- Obesity
- Pulmonary edema
- Tension pneumothorax
- Trendelenburg position?
What is the initial compensation mechanism for acute respiratory acidosis ?
Increase plasma Bicab through plasma protein buffering (Hgb in RBC CO2 reacts with H2O to produce HCO3 and hydrogen, which this bicarbonate will exchange with CI to dump it in blood and raise blood HCO3)
Then urinary excretion of CI to reabsorb HCO3 happens later hours-days.
Will you have aspiration pox in asymptotic hiatal hernia repair?
Yes the asymptomatic and symptomatic at risk for aspiration even if no GERD sx because of esophagus dysfunction.
correcting high INR with Vit K?
No bleeding + INR <5 + elective then withholding warfarin for several days warfarin (1/2 t is 2-4 days).
No bleeding + INR >5 + surgery > 24 hrs then give Vit K
Bleeding, or INT> 10-> high dose Vit k (5-10 mg)
How do you correct high INR for urgent/emergent cases or active bleeding?
PCC (prothrombin complex concentrates) + Vit K
2 form of PCC; 4 factors (1972) and 3 factors (192) which factor 7 should be supplemented
S/E TRALI, and transfusion associated circulatory overload.
Ventilation goals in bronchipleural fistula?
End expiratory pressure
Short inspiration time
Low TV
Low RR
Spontaneous ventilation preferred over PPV.
Lung isolation decreases pressure and volume ( the theory of its benefit, ventilating both lungs may cause barotrauma and voluteuma to healthy lung since higher pressure needed to overcome through the fistula teak)
Mgmt of bronchopleural fistula?
Lung isolation with double lumen.
High frequency jet ventilation (delivers small TV under high pressure) but this causes hyperinflation and HD instability
If all falls then ECMO
Post op A-fib risks?
- cardiac/thoracic surgeries also large abdomen/vascular procedures
- present cardiac or Lung dis (HTN, valvular, copd/asthma …)
- intraop volume status (hypo triggers catecholamines from decreased i2 delivery, and increased catecholamines triggers AF) (hypervolemia also triggers AF through atreual mechanical stretch)
Whats the BP conversion number for change in cuff height ?
The conversion is 0.75 mm Hg per 1 cm change in height relative the reference point (e.g. the level of the heart), adding when the cuff is below and subtracting when the cuff is above the level of the point of reference.
(pH = 15 20) 15 mmHg = 20 cm change
how preterm labor caused in pregnents with spinal cord injury?
Autonomic hyperreflexia results from the absence of central inhibition on the sympathetic neurons in the spinal cord below the injury. Uterine contractions can stimulate autonomic hyperreflexia. This can result in vasoconstriction, therefore fetal hypoxia and bradycardia.
Neurogenic shock vs Autonomic hyperreflexia?
Neurogenic shock following acute high spinal cord injuries (SCI) is associated with severe bradycardia and hypotension from unopposed vagal or parasympathetic activity and loss of cardiac accelerator fibers (if injury is above T1-T4). There is a loss of sympathetic function, which cannot oppose vagal response during stimulation. (so during DL; Nerve transmission unable to activate the thoracic sympathetic)
Autonomic hyperreflexia begins 2-3 weeks following acute injury. It may occur with stimulation below the level of spinal cord injury leading to uninhibited sympathetic stimulation. Approximately 85% of cases occur with SCI above the T5 level.
Lung volumes? the capacities (there is 3) - - FRC= residual volume + ….
- VC = All except ….
- TLC= Everything
- functional residual capacity is the RV + ERV (expiatory reverse volume).
- RV
DDx for delayed emergence or awakening?
Anesthesia related (residual anesthetic/ms relaxants, psudocholinesterase deficiency, excessive narcotics)
Metabolic (hypothermia, hypoxia, hypercarbia, hypo Na/Ca/glucose, renal/hepatic dysfunction)
Intracranial event (stroke/CVA, seizure, increased ICP)
Ondansetron is known to cause QTc prolongation in nearly 20% of patients but its very rarely clinically significant, why?
The prolongation is typically 20-30 msec or less, which is clinically insignificant (though statistically significant) except in patients with already prolonged QTc intervals or those with additional risk factors for prolonged QTc intervals (e.g. hypokalemia, hypocalcemia, hypothyroidism, history of myocardial infarction, long QT syndrome, and recent use of other medications that prolong the QTc interval).
Further prolongation of the QTc interval potentially places patients at risk for the development of arrhythmias, notably torsades de pointes. This lead to placement of a black box warning on the medication in the U.S. in 2011 by the Food and Drug Administration. However, it is worth noting this warning was focused on the 32 mg single IV dose. Current recommendations are that no single dose be larger than 16 mg IV.
Common side effects of Zofran?
- QTc prolongation (20%, very rarely clinically significant).
- headache (11%)
- transient AST/ALT increases (5%),
- constipation (4%), rash (1%), flushing/warmth (< 1%), and dizziness (< 1%).
5 types of PONV medications used?
when is the re-dosing of zofran can be considered?
is metoclopramide recommended for PONV?
1) 5-HT3 receptor antagonist (e.g., ondansetron): Do not re-dose unless more than 6 hours have elapsed since the last dose was administered, including in the immediate post-operative period. An adverse effect is QTc prolongation.
2) NK-1 receptor antagonist (e.g., aprepitant): more effective than ondansetron. Recommended to give prior to the start of surgery.
3) Corticosteroids (e.g., dexamethasone): recommended dosing is 4 mg at the beginning of the surgery due to long onset time.
4) Dopamine-2 receptor antagonist (e.g., droperidol, metoclopramide): droperidol is effective as an anti-emetic. Recommended dosing is 0.625 to 1.25 mg at the end of surgery. Metoclopramide is considered a weak anti-emetic. The effective dose for metoclopramide is 25 to 50 mg. Metoclopramide 10mg is not recommended for PONV. Also, metoclopramide is not recommended as an antiemetic for patients who have received prophylactic ondansetron intraoperatively.
5) Anti-cholinergics (e.g. scopolamine patch): need to apply prior to going back to the operating room due to its 2 to 4 hour onset time. Can cause visual changes, dry mouth, and dizziness.
PONV Risk Factors in Children?
PONV Risk Factors in Adults Age < 50 years old Female gender History of PONV or motion sickness Non-smoker
PONV Risk Factors in Children Age > 3 years old History of nausea/vomiting (in the child or relative) Strabismus surgery Surgery > 30 minutes
perioperative factors associated with increasing and decreasing PONV
Increases Incidence of PONV
Duration of anesthesia
Opioid use (especially post-operatively)
Surgery (laparoscopic, cholecystectomy, gynecological)
Use of nitrous oxide/volatile agents
Decreases Incidence of PONV Adequate hydration??? Avoid nitrous oxide??/volatile agents Minimize opioid use Regional anesthesia (avoid general anesthesia) Use of propofol
Neostigmine dosage for reversal?
0.07 mg/kg neostigmine, up to 5 mg maximum
Risk factors for Postoperative cognitive dysfunction (POCD) ?
Advancing age, lower educational level, and a history of previous cerebral vascular accident with no residual impairment.
what is laryngospasm? who is at risk?
Reflex adduction of the true and false vocal cords and linits air move in.
results from light plane of anesthesia, extubation during stage II, oropharyngeal secretions, or in patients with recent respiratory tract infections.
It occurs more frequently in children, in those with reactive airway disease, and those who have second-hand smoke exposure.
Laryngospasm management?
100% oxygen with positive pressure < 20 cm H2O, Larson maneuver, ( 3-5 seconds of pressure to the retromandibular notch), optional IV anesthetic ( 3-5 seconds of pressure to the retromandibular notch), and last resort IV succinylcholine (0.5 mg/kg).
Goals to prevent PONV?
While we would like to prevent PONV in order to decrease PACU stays, avoid unexpected admissions, and improve patient satisfaction, vomiting and retching have been associated with severe side effects. This includes aspiration, suture dehiscence, esophageal rupture, subcutaneous emphysema, or pneumothorax.
Where dose seretonin released from? and how nausea & vomiting develops?
Toxic substances can lead to the release of serotonin from the enterochromaffin cells in the gut wall.
Serotonin is released near afferent vagal nerve endings of the gut wall that travels to the dorsal brainstem through the nucleus tractus solitarius.
Toxins and drugs are thought to cause nausea and vomiting through stimulation of the chemoreceptor trigger zone. The CRTZ is located in the area postrema at the bottom of the 4th ventricle. (The CRTZ is outside of the blood-brain barrier and leads to nausea and vomiting through the direct action of drugs and toxins on the CRTZ, and not through the release of serotonin.)
Salted emergence can be caused by neostigmine or glycopyrolate?
Glyco, the anticholenergic agent not the reversal anticholeaterase
Lower extremity sensation test after block:
L1 -> inguinal ligament L2 -> later side of thigh L3 -> medial thigh L4 -> medial side of first toe L5 -> lateral side of second toe
Flexion of hip -> L1 + 2
Extension of knee -> L3 + L4
Flexion of knee -> L5 - S2
NaHCO3 effect to consider when administering
- Transit increase in EtCO2 and PaCO2
- Increased ICP (the CO2 generates when bicarbonate binds to H+ produces CO2 which will increase cerebral BF and increase ICP)
- transit decrease in Ca & K
- hypotension due to hypoCa and ventricular depression effect as well as redistribution of blood to plum vascular)
Intraop Anaphylaxis mgmt ?
Remove all considered allergen. Remove all latex D/C meds Intubation? IVF bolus ~50 mL/kg Epi 0.01 mg/kg D/C anesthetic
Cause of acute hemolytic transfusion anemia
ABO incompatibility
Cause of febrile transfusion rxn?
Donor cytokines and Ab reacting to recipient leukocyte
Cause of delayed hemolytic transfusion ex?
Recipient Ab and complement attack on donor RBC (usually Ab associated to Rh, Kidd or kelp system)
Graft versus host disease
Lymphocytes I donor blood reacting against recipient tissue and the recipient is unable to reject the donor lymphocyte because of immunodeficiency/immundeppression
Rash, fever, cytobenia, liver dysfunction and later diarrhea are symptoms
Ppx against GI bleeding in gastric ulcer are …. but … provide better protection against ventilation associated pneumonia
PPI or H2 blocker.
Sucralfate
What decreases SvO2?
Increase O2 consumption (hyperthermia, shivering, pain)
- decreases CO ( MI, hypovolemia)
- decreases Hgb %
- decreases PAO2
What increases SvO2
- decreased VO2 (Cynide, sepsis, CO poison, methemoglobinmia, hypothermia)
- increases CO (sepsis, left to right shunt)
- increase Hgb, concentration via transfusion
- increased SaO2
SvO2 directly related to Hgb, SaO2 and CO but inversely related to total body O2 consumption
Static vs dynamic lung compliance?
Static compliance : measuring the lung at fixed volume
Dynamic: measuring lung during normal rhythmic breathing.
Factors increase delirium/emergence agitation?
Dementia, lower education, EtOH, age
Refeeding syndrome
This is more common in patients who are nutritionally depleted, defined as a greater than 10% loss of body weight in 6 months or less. Signs include:
- Hypophosphatemia (due to tissue rebuilding), common in chronic alcoholics who restart feeding, may be seen as muscle weakness (signs such as skeletal muscle weakness including respiratory weakness, dysphagia, leg cramps, and constipation.)
- Hypomagnesemia
- Hypocalcemia
- Hypokalemia
Juxtaglomerular apparatus senses the decrease in …… in low RBF and releases renin which converted to Angiotension II that will …. efferent arterioles.
Decreased RBF results in decreased chloride concentration at the level of the juxtaglomerular apparatus which leads to the release of renin. The release of renin causes angiotensin II to be formed which will constrict efferent arterioles and increase glomerular filtration. (When there is decreased chloride concentration at the JG apparatus, the Afferent arterioles dilate and increase glomerular flow and GFR)
The spinothalamic tract is an ascending pathway which transmits …. & ….
pain and temperature
Dorsal column refers to an area of white matter in the lateral/posterior aspect of the spinal cord. It is an ascending pathway which transmits information about …. & ….
localized fine touch and proprioception
The first line therapy for patients with cyanide toxicity
Hydroxocobalamin
Advantages of using a bronchial blocker instead of a DLT?
- Used for selective lobar collapse, such as in cancer patients who have had prior contralateral pulmonary
- Prior oral or neck surgery with challenging airways may better tolerate a bronchial blocker since these patients may not anatomically accommodate larger DLTs.
- Patients with tracheostomies.
- Children < 12 years old generally cannot accommodate even a small DLT because of its size.
- Postoperative mechanical ventilation is anticipated (e.g. following prolonged thoracic procedures with upper airway edema), bronchial blockers through a standard single-lumen endotracheal tube have the advantage of not requiring the endotracheal tube to be exchanged, as would be the case with a DLT.
what factors increased perioperative anxiety in childrens?
Younger children (preschool age), higher cognitive function, shy or withdrawn personalities, and children with anxious parents
Treatment botulism?
Human derived immune globulin in patients less than one year of age and equine derived antitoxin in patients over one year of age.
During periods of intense painful stimulation such as direct laryngoscopy and intubation evidence of myocardial ischemia may occur secondary to tachycardia and hypertension, what are maneuvers that suppress the tracheal reflexes and blunt the autonomic response caused by DL and ETT?
- Deep inhalational anesthesia, opioids, beta-blockers. lidocaine (Significant reduction in the responses to laryngoscopy and intubation can be seen with lidocaine 3 mg/kg, especially when combined with high-dose fentanyl.)
- Ensuring direct laryngoscopy is limited to less than 15 seconds will also help minimize blood pressure changes.
lipolysis increased by STIMULATION ….. adrenergic receptors.
and inhibted by STIMULATION ….
lipolysis is increased by beta-2 and beta-3 adrenergic stimulation
inhibited by alpha-2 stimulation.
so ventolin will take your tommy out but precedex will build karsha
Side effects of HCTZ?
HyperGLUC
Hyper glycemic/lipemia/uricemia/ Calcemia
Anesthetic consideration in Achondroplasia ?
- Airway difficulty with face-mask ventilation due to the dysmorphic features.
- limited cervical mobility.
- Central sleep apnea (due to foramen magnum stenosis and brainstem compression, as well as from increased likelihood of having hydrocephalus and developing abnormal respiratory patterns).
- Obstructive sleep apnea in these patients is due to macroglossia, high-arched palate, and obesity and increased neck circumference also contribute.
- Hydrocephalus may be seen, with concerns for increased intracranial pressure.
The parasympathetic nervous system originates from the … and …. spinal cord. it uses … at all synapses.
Acetylcholine binds to … receptors at the autonomic ganglia and …. receptors at the effector site.
brainstem and sacral spinal cord and uses acetylcholine at all synapses. Acetylcholine binds to nicotinic receptors at the autonomic ganglia and muscarinic receptors at the effector site.
Where are the sympathetic pregangilonic neurons located?
in the lateral horn of the spinal cord from T1-L2.
What would be the first sign of hypoglycemia in patient taken BB (hypoglycemia S&S masked by BB)?
Diaphoresis
Sweat glands are innervated by the sympathetic nervous system and its the only utilize acetylcholine with muscarinic receptors, therefore beta blockade will not prevent sweating with hypoglycemia.
Metabolic ABG abnormality that can impair ventilator weaning?
Metabolic alkalosis, results in compensatory hypoventilation to rise PaCO2 to correct pH.
post-pyloric feeding tube does not reduce the risk of aspiration. It has been shown to decrease the risk of …. , but not aspiration events.
Pnumonia
Advantage of enternalfeeds over TPN?
- Avoidance of intravascular access and a dedicated TPN port, including the complications of intravascular access such as infections
- A greater variety of nutrients can be administered through the gastrointestinal tract that are not available parenterally
- Ease of preparation and reduced cost
- Maintenance of gut function and integrity since the gut derives the majority of its energy substrates from luminal food; This reduces the translocation of bacteria from the gut and the risk of intestinal villous atrophy
- Enteral feeding is associated with overall decreased mortality and complications compared to TPN
Preservation of Total hepatic blood flow (THBF) amongst volatile anesthetics at 1 MAC, from greatest to least is ….
Desflurane> sevoflurane > isoflurane > halothane.
Halothane causes the most hepatic arterial vasoconstriction and therefore the highest reduction in THBF, HABF, and oxygenation among the volatile anesthetics.
Multiple sclerosis patients, most upragulated Ach receptors and increased risk for hyperkalemia with succ who develop lesion in …..
Patients at risk are those with lesions involving motor nuclei (as is evidenced by flaccidity), spasticity, or hyperreflexia
What would be the choice of anelgesia in patients with symptomatic idopathic intracranial hypertension during labor?
intrathecal catheter may be a great option to allow for removal of CSF if symptoms worsen during labor.
Mechanism by which tricyclic antidepressants (TCAs) provide analgesia in non-cancer related pain?
NMDA antagonism, opioidergic effects, sodium and potassium channel blocking, and through interfering with the reuptake of serotonin. However, a dangerous side effect profile limits their use in daily practice.
Obstructive lung disease that decreases DLCO?
Asthmatic patients do not have parenchymal disease and their total lung volume is larger. This increases the amount of CO which can be absorbed. Asthma is different from other obstructive conditions, which have a decreased DLCO from parenchymal damage.
How DLCO test work? what is testing for? what effects its testing to be increased or decreased? and mention examples increased/decreases it?
The DLCO uses carbon monoxide diffusion to assess the parenchymal function of the lungs.
DLCO is effected by cardiac output and hemoglobin concentration.
The DLCO is elevated in conditions like: asthma, polycythemia, pulmonary hemorrhage, exercise, and left to right shunts. It is decreased in pulmonary embolism.
Orthodexia (dyspnea when transitioning from the supine to upright position) is a feature of …. syndrome?
Hepatopulmonary syndrome (HPS) is characterized by the triad of liver dysfunction, unexplained hypoxemia, and intrapulmonary vascular dilations. One of the unique features of this syndrome is orthodeoxia,
Cardiac arrest associated with laparoscopy is caused by either …. or …..
Cardiac arrest associated with laparoscopy is caused by either vasovagal response or gas embolism. Acute stretching of the peritoneum is much more likely to cause asystole. Carbon dioxide embolism can occur secondary to misplacement of the needle or gas entering the circulation through an opening in any injured vessel. Most carbon dioxide that enters the circulation will not cause any effect because it is very soluble and will be excreted through the lungs. Large embolus may occur, presenting as profound hypotension, cyanosis, arrhythmias, and/or asystole. A grinding murmur may be heard on auscultation of the precordium and end-tidal carbon dioxide suddenly increases followed by acute decrease secondary to cardiovascular collapse.
Cerebral blood flow is directly related to …
Cerebral blood flow is inversely related to …
Cerebral blood flow remains unchanged …
Temperature, PaCO2, and extremes of MAPs (< 50 or >150 mm Hg).
PaO2 when less than 50 mm Hg.
within the autoregulatory range of MAPs (50-150 mm Hg) and with PaO2 >50 mm Hg.
Food allergy that is associated to latex allergy ?
avocados, bananas, chestnuts, kiwi fruit, papayas, potatoes, tomatoes
Sodium citrate vs metoclopramide vs H2 blockers effect on decreasing PONV
Sodium citrate will increase gastric pH but has no effect on gastric emptying.
Metoclopramide increases lower esophageal tone and has both anti-emetic and increased gastric emptying effects. Metoclopramide’s gastric emptying effects are due to peripheral D2 antagonist and 5HT-4 agonist effects and its anti-emetic effects are due to central D2 antagonist and 5HT-3 antagonist effects at the chemoreceptor trigger zone.
H2 receptor blockers will increase gastric pH and decrease gastric volume by decreasing gastric acid secretion.
The spinal cord ends at … in infants compared to … in adults.
The spinal cord ends at L3 in infants compared to L1 in adults.
Dosage of amiodirone in shack able ALCS ?
300 then the round after 150
HD changes during CEA related too?
Manipulation of carotid sinus (not body), denervation, and impaired sensitivity of the carotid sinus.
Leads to hypotension and bradycardia (+parasympathetic and decrease in sympathetic discharge)
Can be prevented by local anesthetic injection and stopping manipulation
Carotid sinus or body responsible for mechanoreceptors (respond to mechanical pressure)?
Sinus (the carotid body is a chemoreceptors which respond to chemical substance )
Think “sinus pressure” to remember carotid sinus responsible for HD changes upon stimulation
Signs of LOW mineralocorticoid activity and asymptomatic males/masculinized females is a CAH …..
21 hydroxylase deficiency
CAH with signs of HIGH mineralocorticoid activity and signs of HIGH sex hormones:
11 beta-hydroxylase deficiency
CAH with signs of HIGH mineralocorticoid activity and signs of LOW sex hormones:
17 alpha-hydroxylase deficiency
Intraoperative management of acute hypertension for patients undergoing removal of pheochromocytoma includes
Avoiding medications that are histamine-releasing and utilization of direct-acting vasodilators (e.g., nicardipine (A), nitroprusside (D), and nitroglycerin) or α-blockers (e.g., phentolamine (B)). This is especially important during induction if preoperative α-blockade was not achieved or was begun < 48 hours prior to surgery. If documented preoperative α-antagonism has been instituted (typically phenoxybenzamine), judicious use of a short-acting β-blocker (e.g., esmolol) may be utilized for cardiac arrhythmias or tachycardia.
Consideration for hypertension or hypotention in pheochromocytoma resection?
Controlling intraoperative hypertension (during manipulation) and also should take into consideration the hypotension which may ensue following venous ligation of the pheochromocytoma tumor. This occurs as a result of the immediate reduction of circulating catecholamines and the lingering presence of long-acting agents (e.g., phenoxybenzamine, labetalol, doxazosin). Vasopressors, inotropes, and fluid resuscitation should be available in anticipation of hypotension.
2 types of sweat glands are? Their distribution? And neurotransmitters?
Eccrine:
- all body except (lips, penis, clitoris)
- sns -> nicotinic -> sns postganlionic -> MUSCARINIC (Acetylcholine)
- primary form of cooling
Apocrine:
- armpits, perinatal area
- sns -> nicotine -> sns postganglionic -> adrenergic (alpha 1) (catecholamines)
Oculocardiac reflex pathway?
“Five and dime reflex” it starts in the 5th CN (trigeminal) and exits the 10th CN (vagus)
Medications MUSCARINIC agonists direct and indirect (by inhibiting the break down of ACh)
Direct: choline esters (ACh, methacholine, carbachol, bethanechol) alkaloids (pilocarpine, muscarine, arecoline)
Indirect (physostigmine, neostigmine, pyridostigmine, edrophonium, echothiophate)
Antimuscarinic meds?
Atropine, scopolamine, glycopyrrolate
Oculocardiac reflex pathway
Stimulation of rye stretch receptors -> ciliary ganglion -> trigeminal N (afferent) -> gasserian ganglion -> trigeminalnucleus -> vagus (efferent) -> bradycardia
Pathophysio of MH?
Mutation encoding for abnormal dihydropyridine receptors located in the t-tubule membranes skeletal muscle or the ryanoide receptors that allow the release of Ca from sacriplasmic reticulum in SM cells.
Exposure to triggers causes unregulated release of Ca from the SR into intercellular leading to excessive intracellular Ca accumulation that causes sustained contraction and muscle breakdown, rhabdo, anaerobic metabolism and acidosis
Dantrolene inhibits Ca release by binding to RYR1 receptors
SLUDGE-Mi symptoms of … and the opposite sx seen with ….
Cholinergic sx and ACh inhibitor or poisons.
Opposite sx with anti-ACh medications (Atropine, glyco, neostigmine)
Best lab test measures synthetic liver function?
PT
Because Factor 7 has the shortest half-life (4-6 hours) of all other clothing factors, a liver disease will show elevated PT early on.
Albumin remains normal for sever days after liver injury and PTT involves the other clotting factors which has t1/3 longer then factor 7
Mnemonic for warfarin, Extrinsic, PT
And for Vit k dependent factors
WEPT
1972
The current guidelines for NPO status recommend waiting for a minimum of:
- … hours after ingestion of clear liquids
- … hours after ingestion of breastmilk
- … hours after ingestion of nonhuman milk, formula, or a light meal (“tea and toast”)
- … hours after ingestion of a full meal or fatty foods
- 2 hours after ingestion of clear liquids
- 4 hours after ingestion of breastmilk
- 6 hours after ingestion of nonhuman milk, formula, or a light meal (“tea and toast”)
- 8 hours after ingestion of a full meal or fatty foods
Anesthetic risk factors for decubitus pressure injuries include …
prolonged anesthesia, hypothermia, and hypotension
Herbal supplements that affect bleeding and increases preioperative risk?
Many of them starts with letter “G”
Garlic, ginger,ginkgo, green tea, and saw palmetto
Most common abused drug by anesthesia is …
Fentanyl
Immediate next step if the wire inserted into cratoid artery during CVP line placement
Do not insert the dilator. Remove the wire and apply pressure.
Spinal cord ends at L …
1
In neonates L3
Rhabdomyolysis can occur following a multitude of clinical pictures. In the operative period, it can occur following …
malignant hyperthermia, prolonged tourniquet application, compartment syndrome and prolonged operative times in larger (bodybuilder) patients.
There are several PONV scoring systems, Apfel et al developed the most common one used which gives the following risk factors: …
female, history of motion sickness or PONV, nonsmoker, and use of opioids for postoperative analgesia.
The risk of PONV with 1 risk factor is 20%, 2 is 40%, 3 is 60% and 4 is 80%.
Complications with aspiration are more likely to occur with …
larger volume aspiration
low pH aspiration
or particulate aspiration
Common characteristics shared by substance abusing anesthesiologists include:
half are < 35 years old, high incidence of polysubstance abuse, opioids as the drug class of choice, and a higher prevalence noted in academic environments.
Venturi effect?
The Bernoulli principle is useful when considering flow through a narrow orifice (valvular or airway stenosis). Pressure Gradient = 4 * (Velocity)^2
Venturi masks (or venti-masks) use the Bernoulli principle to deliver a specific concentration of oxygen to the patient. The mask uses 100% oxygen flowing into a wider point via a narrow orifice. Because of the narrowing, the oxygen speeds up and the pressure drop at that point is below atmospheric pressure. This causes room air to be drawn to this low pressure point, hence diluting the 100% oxygen to the calibrated value set by nozzle. This is known as the Venturi effect and is a consequence of the Bernoulli principle.
Why the treatment for aortic stenosis is increasing afterload
According to the Bernoulli principle, in aortic stenosis the pressure across the valve decreases because the velocity of blood flow is increased. This results in decreased pressure in the aorta resulting in reduced coronary perfusion. The management of aortic stenosis therefore involves increasing systemic vascular resistance.
In order to prevent rebreathing of carbon dioxide in a traditional circle system, three requirements must be fulfilled:
- A unidirectional valve must be positioned between the patient and both the inspiratory and expiratory limbs.
- Fresh gas flow cannot come into the circle system between the patient and the expiratory valve.
- The APL valve cannot be positioned between the patient and the inspiratory valve.
The most common and reliable sign of cyanide toxicity is …
an anion gap metabolic acidosis.
Carbon dioxide is transported in the blood as …
dissolved CO2, bicarbonate, and carbamino compounds
Minutes until hypoxemia =
(FRC/O2 consumption) x O2% in FRC
FRC = 30 ml/kg
O2 consumption = 3-4 ml/kg/min
O2% depends on pre-oxygenation (usually 100%), if pre-oxygenation did not occur then room air (21%) is assumed.
What’s primary determines delirium
Attention problem (Joyce words)
