Essentials Final.docx

EXAM #1 Nose accounts for ⅔ total airway resistance Pharynx nasopharynx extends from base of skull to upper surface of soft palate contains adenoids, pharyngeal tonsils, lymph tissue, Eustachian tubes opening oropharynx extends from uvula to level of hyoid bone contains palatine tonsil, epiglottis,...

EXAM #1 Nose accounts for ⅔ total airway resistance Pharynx nasopharynx extends from base of skull to upper surface of soft palate contains adenoids, pharyngeal tonsils, lymph tissue, Eustachian tubes opening oropharynx extends from uvula to level of hyoid bone contains palatine tonsil, epiglottis, tongue, uvula hypopharynx (Laryngopharynx) inferior to epiglottis where common pathway diverges into larynx & esophagus pathways Larynx C3-C6 modulates sound separates trachea & esophagus during swallowing composed of muscles, ligaments, cartilages, glottis Vocal cords are the narrowest portion of the adult airway anterior-posterior dimensions of the vocal cords approximately 23 mm in men approximately 17 mm in women Cartilages of the Larynx single thyroid cricoid only complete ring of trachea epiglottis paired arytenoid corniculate cuneiform Trachea Begins @ C6, overlies T5 16-20 horseshoe-shaped cartilages Nerves glossopharyngeal sensory branch to pharyngeal mucosa & posterior ⅓ of the tongue gag reflex vagus superior laryngeal internal branch — sensory to both sides of the epiglottis & airway mucous above the vocal cords external branch — motor innervation to the cricothyroid muscle internal laryngeal recurrent laryngeal sensory BELOW vocal cords to the trachea motor to all muscles of the larynx EXCEPT cricothyroid muscle abduct = posterior cricoarytenoid adduct = lateral cricoarytenoid (principle adductors) Injured nerves recurrent laryngeal unilateral = hoarseness bilateral = abduction of the cords results in strider or occlusion physical examination mallampati classification A classification of the OROPHARYNGEAL SPACE protrude tongue WITHOUT pronating CLASS I — soft palate, uvula, tonsil pillars are visible CLASS II — soft palate & partial uvula are visible CLASS III — soft palate & base of the uvula are visible CLASS IV — soft palate is NOT visible Cormack & Lehane laryngoscopy view Grade 1 — most of glottis is visible Grade 2 — only the posterior portion of the glottis is visible Grade 3 — the epiglottis, but no part of the glottis can be seen Grade 4 — no airway structures are visualized thyromental distance less than 3 fingers (< 6.5 cm) = difficult airway micrognathia (short distance) limits the ability to move tongue & tissue out of pharyngeal space = laryngeal structures positioned anterior 6.5 cm is considered a normal airway 6 cm or less often indicates difficulty moving the tongue anteriorly & visualizing the larynx sternomental distance distance from the tip of the chin (mental) to the sternal notch mouth opening if < than 4-5 cm (2 finger breaths) between the upper & lower incisors indicates a possible difficult airway head & neck movement ability to prognath upper lip bite-test class 1 — lower incisors can bite above the vermillion border of the upper lip class 2 —lower incisors cannot reach vermillion border class 3 — lower incisors cannot bite upper lip dentition hyomental distance (HMD) measures the tip of the chin to the hyoid bone & gives information about the ability of the tongue to be moved anteriorly in the mandibular space a difficult airway should be expected if the HMD is < 3.5 cm the only measurement that is not affected by age or gender Obesity patient with BMI’s > than 30 & neck circumference > 40 cm have a 5% higher risk of difficult airways neck circumference > than 60 cm have a 35 % increase risk of difficult intubation mallampati of 3 or 4 in these patient increases the risk of hypoxemia with laryngoscopy Pediatric airway mallampati is often NOT a good predictor in children There are fewer predictive tests for children & techniques used in adults may not be applicable to children. More likely to encounter congenital disorders which increase difficult airway problems COMPREHENSIVE HISTORY may give best information look at size of head, facial features, size of tongue, incisors, ROM signs of retraction-use of sternal or intercostal muscles = sign of obstruction Pediatric airway differences epiglottis = larger, stiffer, more NARROW in children until about 2 years of age very large tongue compared to oral cavity can’t “sweep” the tongue out of the way use MILLER glottis narrowest portion of adult airway used to believe that the cricoid cartilage is the narrowest of child’s airway but new studies indicate it is the glottis clinical implications = ok to use cuffed ET tubes in children Airway Management difficult & failed airway management account for 2.3% of anesthetic deaths in U.S. anesthesia providers are airway experts definitive airways spontaneously breathing endotracheal tube nasal endotracheal tube surgical airway cricothyrotomy tracheotomy **SUPRAGLOTTIC IS NOT A DEFINITIVE AIRWAY Failure to intubate = not life threatening failure to ventilate & oxygenate = life threatening pre-oxygenation duration of apnea without desaturation (DAWD) goal = ETO2 > 90% 3 minutes of 100% O2 or 8 deep breaths in 60 seconds a healthy patient can maintain SaO2 > 90% for approximately 8.5 minutes obesity, pregnancy, pulmonary disease decrease DAWD bag-mask ventilation hold bag with left hand, fingers lift mandible into m,ask, don’t squish mask down, right hand on bag ventilating pressure should be < 20 cm H20 indications of difficult mask age (> 55 years old) BMI > 26 Facial hair edentulous (no teeth) H/o snoring/sleep apnea repeated attempts @ laryngoscopy mallampati class 3 or 4 neck radiation male gender unable to prognath oral airways displace tongue from posterior pharyngeal wall may stimulate gag reflex nasal airways better tolerated in awake or lightly anesthetized patient ABSOLUTE contraindications coagulation abnormalities basilar skull fractures midface instability RELATIVE contraindications suspected nasal foreign bodies recent nasal surgery h/o frequent epistaxis a bloody nose can ruin everything NETT indications dental procedure intraoral/oropharyngeal surgeries questionable cervical spine stability limited mouth opening (jaw wired shut) oral ETT = gold standard in airway management always have 1 size smaller & 1 size larger infants/small children can use cuffed or uncuffed tubes indications provide a patent airway prevent aspiration need for frequent suctioning facilitate positive-pressure ventilation operative position other than supine operative site near or involving the upper airway ETT placement confirmation sustained ETCO2 (3-5 consecutive breaths) bilateral chest movement bilateral breath sounds & absence of sound over stomach ”feel” on the reservoir bag & expiratory refilling of the bag condensation of H20 in tube lumen (breath fogging) laryngoscope blade most common for adults Mac #3-#4 (curved blade) place in vallecula Miller #2-#3 (straight blade) place beneath epiglottis **MAC #3 most common for 60 kg patient Cricoid pressure aka “Sellicks” ,maneuver assistant exerts downward external pressure with thumb & index finger on cricoid cartilage compresses esophagus against cervical vertebrae pressure of 30-40 newtons (3-5 kg) should be applied BEFORE induction of anesthesia don’t release cricoid pressure until you are absolutely sure the ETT is correctly placed ideally after ETT is secures Complications of laryngoscopy dental trauma (1 in every 4500 patients) Dislodged tooth should be recovered, if not recovered then x-ray systemic hypertension & tachycardia (usually transient) most common = lip lacerations & retropharyngeal dissection Aspiration Mendelson’s Syndrome — pH < 2.5 or greater than 25 mL of gastric content aspiration pneumonitis risks pregnancy, acute GI disease (small bowel obstruction, ileum, esophageal disease), trauma, DM, obesity, narcotics, full stomach Sniffing position laryngoscopy requires distortion of the normal anatomical planes of the upper airway to produce a line of direct visualization from the anesthetist’s eye to the larynx trying to create a new visual axis through alignment of the axes of the oral & pharyngeal cavities to displace the tongue OA = oral axis PA = pharyngeal axis LA = laryngeal axis best position is head on pad, neck flexed, head extended on neck, axes aligned Positioning raise patient’s head for sniffing position: to optimize the LA & PA raise head (about 10 cm) positioning obese patients in the sniffing position can be difficult d/t FAT PAD on back— will need to “ramp” the patient SATA Q place blankets under shoulders to lift pad ear to sternal notch raise head 10 cm Prepare for extubation initial plan — “deep” extubation or “awake” extubation bite block in place throat pack removed pre-oxygenation w/ 100% (NOT 50%) suction pharynx Criteria for extubation adequate oxygenation adequate ventilation hemodynamically stable neurologically intact intact gag/cough reflex follows commands normothermic ensure full reversal of muscle relaxation sustained tetany train of four ratio > 0.9 (4 strong twitches) sustained head lift for 5 seconds Laryngospasm air doesn’t move in or out lightly anesthetized patient is MOST @ risk —make sure they are either awake or deep secretions irritate larynx (suction) break the laryngospasm succinylcholine 0.1 mg/kg IV positive pressure through face mask forward displacement of mandible (aka Larson’s maneuver) take a look @ the airway algorithm!!! SUPRAGLOTTIC airways supraglottic means “above the glottis” or “above the larynx” LMA— classic, unique, fastrach, proseal, supreme all have 3 main components: mask, airway tube, & inflation line advantages compared to facemask — hands-free operation, better seal in bearded patients, less cumbersome in ENT surgery, often easier to maintain airway, protects against airway secretions, less facial nerve/eye trauma, less operating room pollution disadvantage compared to face mask — more invasive, more risk of airway trauma, requires new skill, deeper anesthesia required, requires some TMJ mobility, N20 diffusion into cuff, multiple contraindications advantages compared to ETT — less invasive, very difficult intubations, < tooth/laryngeal trauma, < laryngospasm/bronchospasm, does not require muscle relaxation or neck mobility disadvantages compared to ETT — increased risk of gastric aspiration, < safe in prone or jackknife positions, limits maximum PPV (LMA = 20, ETT = 40), less secure airway, greater risk of a gas leak & pollution, can cause gastric distention contraindications of LMA absolute (in ALL settings, including emergent) cannot open mouth complete upper airway obstruction relative (in the elective setting) increased risk of aspiration prolonged bag-valve-mask ventilation morbid obese 2nd or 3rd trimester pregnancy full stomach up GI bleed suspected or known abnormalities in supraglottic anatomy need for high airway pressures (pressure should not exceed 20 mmH20) LMA classic lateral edges rest in the piriform sinuses proximal end seats under base of tongue distal tip sits @ upper esophageal sphincter size selection is determined by WEIGHT LMA Fastrach allows for blind intubation through LMA (primary objective) anatomically curved stainless steel tube has attached handle to aid insertion of device & to assist in ETT insertion LMA ProSeal modification of LMA classic 2nd lumen that parallels airway tube but opens @ distal tip acts as esophageal vent protects against aspiration ONLY if it is optimally seated NOT a guarantee to prevent aspiration LMA Supreme single-use disposable gastric port/tube minimizes gastric insufflation decreases risk of aspiration but NO guarantee LMA insertion technique — deflate cuff, index finger & middle finger on either side , insert into mouth & advance following the palate & posterior pharyngeal wall until resistance is met, let go of mask & tube, inflate the cuff, allowing the device to move into position LMA complications aspiration of gastric contents local irritation upper airway trauma pressure-induced lesions nerve palsies mild sympathetic response complications associated with improper placement obstruction laryngospasm bronchoconstriction LMA sizes/volumes normal adult < 70 kg = mask size 4, cuff volume up to 30 mL large adult >70 kg = mask size 5, cuff volume up to 30 mL Role of LMA in difficult airway algorithm factors r/t difficult tracheal intubation DO NOT correlate with difficult LMA placement therefore, the incidence of experiencing difficulty with both ETT & LMA placement is very low SAD Combitube double-lumen can function as either an endotracheal device or esophageal obturator passed blindly or w/ laryngoscope ventilate through the longer (blue) lumen if no breath sounds are heard, try other lumen King laryngeal tube ability to pass gastric tube through distal port blind insertion Advanced Airway management Awake fiber optic intubation indications for fiberoptic Anticipated difficult tracheal intubation/ventilation confirm ETT position diagnosis of malfunction of a supraglottic airway device cervical spine instability positioning of double-lumen tube & bronchial blockers assessment of swelling or trauma after difficult airway tracheal tube change aspiration of secretions & confirmation of dilational tracheotomy site fiberoptic technique Targets kept in center of view while advancing fiberoptic contraindications NO absolute contraindications cannot be performed without patient cooperation unlikely to work if airway bleeding arytenoid cartilage can be displaced laryngeal damage complete airway obstruction usually due to heavy sedation nerve blocks translaryngeal block anesthetizes BELOW the cords stimulates cough (good) 20 gauge or smaller 3-5 cm plastic catheter over a need is introduced midline inner steel cannula is withdrawn aspiration of air confirms placement 3-5 mL of 4% lidocaine injected rapidly superior laryngeal nerve patient supine hyoid bone is displaced laterally TOWARD the side to be blocked 25 gauge, 2.5 cm is walked off the greater Cornu of the hyoid bone inferiority & advanced 2-3 mm as need passes through membrane, loss of resistance is felt 3 mL of local anesthetic is injected repeat on opposite side anesthetizes inferior aspect of epiglottis to vocal cords Intraoral approach to glossopharyngeal nerve block 5 mL of local anesthetic into base of each posterior tonsillar pillar CAREFUL aspiration before injection d/t close proximity to CAROTID ARTERY bougie useful for epiglottis-only view (grade 3) cook catheter can be used as an exchange catheter can ventilate through using jet ventilator (unlike bougie) lighted stylet tip of stylet uses bright light to visualize location through the skin of the neck localized glow indicates tracheal position diffuse glow indicates esophageal position obesity or skin pigmentation may alter results glidescope good in patients with limited neck extension or anterior airways McGrath similar to glidescope enhanced direct laryngoscope portal video camera attached to handle cannot intubate, cannot ventilate noninvasive techniques fail may develop rapidly often occurs after repeated unsuccessful attempts @ intubation follow the algorithm! Did you try supraglottic airway? 2 person face mask? Oral/nasal airway? weigh the risk of invasive rescuer technique against that of hypoxia brain damage or death percutaneous airway necessary only when noninvasive techniques fail to relieve the “cannot intubate, cannot ventilate” situation types — surgical cricothyrotomy, welding ear cricothyrotomy, needle cricothyrotomy surgical cricothyrotomy advantageous to tracheotomy d/t superficial nature of membrane being relatively AVASCULAR & QUICKER equipment — no. 20 scalpel, cuffed tracheal to trach tube with 6 or 7 mm diameter VERTICAL incision d/t blood vessels Retrograde intubation/seldinger cricothyrotomy Uses guide wire through cricothyroid membrane too pass through glottis, through oropharynx & allow ETT to over guidewire studies show this takes LONGER than the surgical technique to restore the airway Percutaneous translaryngeal jet ventilation (PTJV) needle cric is performed attach oxygen source wall O2 pressure = 50 psi insufflation of 1-1.5 seconds @ a rate of 12 insufflation per minute a 14 gauge will deliver a tidal volume of 400-700 mL pressure valve is a 1-way valve; therefore, you must allow 3-4 seconds between insufflation for PASSIVE EGRESS of air can cause barotrauma Double Lumen Tubes indications prevent damage or contamination of the healthy lung control distribution of ventilation severe unilateral lung disease (major cyst or bulla) surgical exposure in divided-assisted thorax optic surgery (VATS) single lung lavage: treatment for pulmonary alveolar proteinosis or cystic fibrosis placement Blind technique (direct laryngoscopy) pass tube through glottis w/ distal curvature facing anteriorly once through glottis remove stylet rotate tube 90 degrees once tracheobronchial cuff past cords should pass glottis WITHOUT resistance advance until moderate resistance Confirmation bronchoscope breath sounds — each time tube is placed & patient is repositioned 95% of the time, you will use a left-sided double lumen tube right-sided double lumen tube indications distorted anatomy of entrance to left main stem bronchus surgery involving left main stem bronchus Properly positioned left-sided tube through the bronchoscope, you should see the rim of the blue-bronchial cuff if you see the full balloon = you’re not deep enough if you don’t see any blue = too deep Confirmation of left-sided tube by auscultation clamp tracheal lumen check for unilateral left-side breath sounds persistent right sided sounds = tube note deep enough unilateral right sided sounds = tube incorrectly placed in right bronchus UNCLAMP the tracheal lumen, CLAMP the bronchial lumen **she gave scenario about r-sided isolation & you had to know that you CLAMP the tracheal side & CLOSE CAP on bronchial side DLT relative contraindications Full stomach, airway lesion, extremely critical patients already intubated with SLT, upper airway anatomy (recessed jaw, prominent teeth, bull neck, anterior larynx) #’s to know a difficult airway should be expected if Thyromental distance less than 3 fingers (< 6.5 cm) Mouth opening < than 4-5 cm (2 finger breaths) hyomental distance = < 3.5 cm BMI > 30 & neck circumference > 40 cm have a 5% higher risk of difficult airways neck circumference > 60 cm = 35 % increase risk of difficult intubation ventilating pressure w/ bag-mask ventilation = < 20 cm H20 cricoid pressure = 30-40 newtons (3-5 kg) pre-oxygenation goal = goal = ETO2 > 90 or 3 minutes of 100% O2 When positioning patient’s head for sniff, raise head about 10 cm pressures with LMA should NOT exceed 20 cmH20 Test 2 (red=on test, highlight yellow or bold= was emphasized,bolded on ppt and not asked) Short vs. long axis Short axis- probe/image is perpendicular to desired structure Long-axis- probe/image is parallel to desired structure In plane vs. out of plane In plane- needle is parallel to probe Out of plane- needle is perpendicular to probe\ Hemodynamic monitoring Goal is to assure adequate perfusion for delivery of O2 to tissues Blood pressure measurement is consistently researched but has poor correlation with O2 delivery to tissues MAP doesn't mean good O2 delivery AANA standard of practice Document BP, HR, and respiration at least every 5 minutes for all anesthetics Cardiovascular- cont. Monitor HR and CV status, use invasive monitoring as appropriate Noninvasive BP Sphygmomanometry: auscultation of korotkoff sounds created via turbulent flow due to partial collapse of the constricted artery Allows for measurement of systolic and diastolic pressure Oscillometry: automated NIBP measures pressure fluctuations due to pulsations transmitted to solid-state transducers NIBP limitations-Proper cuff sizing Length- the bladder should cover 80-100% of the distance around the upper arm Width- bladder should extend from 40-75% of the distance from your elbow to shoulder Penaz technique Finger technique Waveforms are analyzed and calculated to provide dynamic vital signs HR, BP, CO, SV, SVV/PPV, SVR Transducer system-NOT A SINGLE HARMONIC WAVE Fluid filled motion systems are dependent on factors of mass, elasticity, friction Reliable waveforms require a balance of frequency (pulse rate) and damping coefficient Ultimate output displayed is a fourier analysis of multiple combined sine waves Wheatstone-bridge undergoing hydraulic coupling Transducer utilizes this Has a galvanometer Allows for continuous monitoring Hydraulic coupling: bridge is bent via mechanical force -> resistance is changed -> voltage differential created Damping coefficient Transducer is connected to the vessel by a fluid-containing system so it is subject to frictional resistance Change in pressure is not immediately transmitted to transducer- delay in response is known as damping Damping normally prevents a system from over responding to change Overdamped (minimal to no oscillations) Overdamping = too high of resistance Slurred upstroke, absent dicrotic notch, loss of fine detail SBP is underestimated DBP is overestimated Pinched phenomenon MAP remains accurate Causes: blood clots, air bubbles, kinks in system, extensions (stopcocks/tubing), malpositioned catheter Underdamped (excessive oscillations) underdamping= too low of resistance Waveforms appears as exaggerated peaks and troughs SBP is overestimated,DBP is underestimated-stretched phenomenon Causes: excessively rigid/short/narrow tubing, tachycardia Calibration-zeroing and leveling Hydrostatic pressure- proportional to the height of the fluid column Proper leveling of the transducer negates the effects of hydrostatic pressure on the system being analyzed Example: a patient in a sitting position such that the external auditory canal is 10 inches above the blood pressure cuff on the arm MAP of arm cuff is 65 mmHg, MAP at EAC would be less than 45 mmHg 1cm=0.74 mmHg 1in=2mmHg Make sure to pay attention to the patient position, he switched it up for the test! Arterial monitoring-current gold standard for BP monitoring Indications: frequent ABGs, continuous real time monitoring when rapid changes are anticipated, failure of indirect BP monitoring, IABP/LVAD, deliberately induced hypo/hypertension, major surgeries, long term vasoactive drug infusions, supplementary diagnostic info desired (mediastinoscopy) Seldinger technique Argyle kit is sterile Arrow kit is aseptic The pressure throughout diastole is also known as peripheral runoff Arterial cannulation site Radial artery Preferred site Inaccuracy of waveform Ulnar artery Complications similar to radial Primary source of hand blood flow Brachial artery Lack collateral circulation Axillary artery Specialized kits Femoral artery Easy access Potential for local/retroperitoneal hemorrhage Longer catheters preferred DP artery Has collateral circulation from PT artery Higher systolic pressure estimates Distal to aortic root Higher SBP Steeper systolic upstroke Lower DBP Lower and later dicrotic notch Wider pulse pressure Analysis of the arterial pressure waveform allows the practitioner to better comprehend the patient’s heart function due to the pressure wave correlation with the cardiac cycle Aortic stenosis Fixed obstruction = reduced SV, slowed rate of ejection Waveform: small in amplitude, slow rising systolic upstroke, delayed peak Aortic regurg Wide pulse pressure May have 2 systolic peaks (pulsus bisferiens) PPV causes variations in arterial pressure Pulse pressure variation Monitoring these cycles, patients preload and fluid status responsiveness can be estimated PPV >/= 13% indicated the patient would benefit from a fluid challenge Low respiratory variation-not volume responsive High respiratory variation-volume responsive CCO-arterial waveform can be analyzed with algorithms to provide further insight into cardiac function Windkessel model-distensible arteries serve as a reservoir between phases of systole and diastole, SV is calculated by comparing these changes in pressure This is mathematically observe by measuring the are under the curve (peripherl runoff) Goal-directed fluid therapy-use of dynamic monitors to guide individualized patient fluid administration Historically, providers utilized fluid restrictive therapy or predictive fluid calculations Only absolute contraindication to CVC is patient refusal CVC should be inserted on the SAME side as the pathologic lung when possible RIJ is first choice Internal jugular Easy visualization with US, direct path to SVC/RA, least risk of DVT Small risk of infection, risk of arterial puncture, decreased patient comfort Subclavian Increased comfort, least risk of infection, small risk of DVT High risk of PTX, risk of bleeding w/difficulty providing compression, risk of long term stenosis Femoral Easy access, compressible if arterial puncture occurs Highest risk on infection, high DVT risk, last resort IJ vein-puncture at apex of sedillot’s triangle formed between 2 heads of sternocleidomastoid muscle The right side provides a more direct route to SVC and is often larger than the L side LIJ/SC-potential damage to thoracic duct can occur Needle always inserted bevel up towards ipsilateral nipple/iliac crest Maintain cont. Need aspiration Do NOT force guidewire at any time, do NOT advance past 15cm, monitor for arrhythmias, maintain control of Jwire at all times Blood coloration is a poor indicator of correct placement Catheter length is best estimated by measuring the distance from the needle insertion point and third rib Average catheter length to the caval-atrial junction (be able to rank these) Right SC: 15 cm Right IJ: 16 cm Left SC: 19 cm Lefit IJ: 21 cm Femoral: 40 cm Catheter tip misplacement Too short: increased venous thrombosis risk or potentials migration into azygous or innominate vein Too long: if in RA, increased likelihood of arrhythmias and cardiac tamponade Infraclavicular approach for CVC placement Identify sternal notch and deltopectoral groove Pt. 10-20 degrees tburg, head neutral Place needle bevel up while aiming toward the sternal notch using a 10-15 degree angle Guidewire placement/confirmation should be performed in long axis view NAVL pneumonic: lateral to medial, nerve ->artery->vein-> lymphatics Test he gave us an example and had to say which injury you were concerned about if you were too medial or lateral CVP waveform A wave Atrial contraction Follows P-wave on EKG Late diastole C wave Closure of tricuspid valve Atrial relaxation + isovolumetric contraction + tricuspid valve closure = tricuspid valve bulges back into RA Just after QRS on EKG Early systole X descent Systolic collapse in atrial pressure Atrial relaxation + ventricular contraction = atrial pressure decline mid-systolic on EKG V wave Atrial pressure increase due to filling of the atrium Tricuspid valve still closed Just after T wave on EKG Late systole Y descent Diastolic collapse due to passive filling Tricuspid open and blood flows from RA to RV = decrease in atrial pressure Early diastole CVP wave pneumonic A wave: atrial contraction C wave: tricuspid closure and ventricular contraction V wave: venous filling of atrium X descent: relaxation of atrium Y descent: emptying of atrium Waveform abnormalities Tricuspid regurg picture (slide 65) Confirming placement of CVC Visual inspection of color of aspirated blood, observation of blood flow characteristics, measurement of the pressure, ABG, use of US, chest xray Radiology Quality determined by: Rotation: relation of radiation to object vertebra midline, clavicles equal, lung apices superior to clavicle Inspiration: full inspiration desired for consistent imagine Projection: object position to detector (PA vs AP) Exposure: brightness, visibility of all structures Tip of central line should sit above the pericardial reflection, approx. 1 cm below carina, thoracic vertebrae 4-5 Chest X-rays of good and bad CVC placement (slide 74) Tracheal deviation Away from affected side: PTX, pleural effusion, mass Towards affected side: atelectasis, lobectomy/pneumonectomy PA catheter Catheter placement is performed by observing the pressure waves as catheter is floated from RA to RV to PA then wedges in a branch of the PA Distances from the RIJ: RA 15-25 cm, RV 25-35 cm, PA 35-45 cm, PCWP 40-50 cm If RV waveform is not seen at 40 cm OR PA waveform not seen at 55 cm, then deflate balloon and withdraw to 20 cm Pressure progression RA: same as expected CVP waveform RV Systolic pressure increases RV systolic range 15-30 mmHg Minimal diastolic pressur PA Similar to RV waveform Diastolic step up Dicrotic notch PA systolic range 15-30, PA diastolic range 5-15 Had to interpret RV vs PA pressures to be able to say if we were in the pulmonic valve Transition from RV to PA would have about the same systolic but an increase in diastolic pressure PAWP Creates a static column during end-diastole since there is cessation of forward blood flow Wedge catheter tip transduces through the pulmonary vasculature and LA to LV Obtained LVEDP is used as a surrogate to indirectly assess LV preload LVEDP normal 4-12 mmHg Mitral regurg PA waveform analysis picture (slide 88) West lung zones Only zone 3 (Pa>PV>PA) allows for uninterrupted blood flow and cont. Communication with left heart cardiac pressures Absent a and v waves indicates incorrect positioning into zones 1 or 2 End-expiratory intrathoracic pressures most closely approximate atmospheric pressure SO measurements should be taken at end expiration to minimize transmural pulmonary and pericardial pressure influence on CVP or PAWP Contraindications to PAC DO NOT float PAC in patients with a LBBB If you have RBBB you risk a complete heart block Endocarditis Tricuspid regurg Concern for coags Thermodilution Gold standard for measuring CO Inject a cold solution which travels from the cavoatrial junction (proximal port) to the PA where the temperature change is measure by a thermistor Measurements can vary with intrathoracic pressures-measure at end of expiration to reduce this variability Transesophageal echo: Quantitative measurements of hemodynamic parameters Transthoracic echo: qualitative assessment of hemodynamic measurements Informed consent: discussion with patient should include benefits, risks, and alternatives