IN ANESTHESIA


•  In pediatric patients a 20–24 gauge needle may be used for the first cannulation and then exchanged with a larger gauge over a guidewire


•  Proceed as described in the standard landmark technique above, but confirmation of the intravenous location of the guidewire with longitudinal view before vessel dilation


Real-time Visualization of SC


•  Transducer is placed in the infraclavicular groove at the level of the middle or lateral third of the clavicle


•  Axillary vein and artery are imaged as they exit the bony canal formed by the clavicle and the first rib


•  Artery is most commonly cephalad to the vein and noncompressible, and does not vary in diameter with respiration


•  Either transverse or longitudinal view for guide needle insertion as described above


•  Proceed as described with landmark technique followed by confirmation of guidewire location in vein



INSERTION OF A PULMONARY ARTERY CATHETER (PAC) (ALSO SEE CHAPTER 7, ON PERIOPERATIVE MONITORING)


Indications


•  Management of complicated myocardial infarction (ventricular failure, cardiogenic shock)


•  Assessment of resp. distress (cardiogenic vs. noncardiogenic pulm edema, 1° vs. 2° pulm HTN)


•  Assessment of shock


•  Assessment of fluid requirements in critically ill (hemorrhage, sepsis, acute renal failure, burns)


•  Postop management of cardiac pts


•  Need for heart rate pacing


Contraindications


•  Tricuspid or pulmonary valve mechanical prosthesis


•  Right heart mass (thrombus and/or tumor)


•  Tricuspid or pulmonary valve endocarditis


Technique


•  Central venous access as described above


•  Positioning: Floating PA catheter easier in flat or slightly reverse Trendelenburg in contrast to central line placement (Trendelenburg)


•  Aseptic technique: Sterile gown, face mask, gloves, skin disinfection, & whole-body drape


•  PAC setup


•  Calibrate (“zero”) PAC, check PAC for damage, test balloon inflation/deflation


• Connect all lumens to stopcocks, flush to eliminate air bubbles


• Check PAC tip frequency response by touching tip


• PAC threaded through sterile sleeve prior to insertion into cannula


•  PAC inserted percutaneously into major vein (IJ, SC, femoral) via an introducer sheath


• RIJ: Shortest & straightest path


• LSC: Acute angle to enter SVC (compared to RSC or LIJ)


• Fem: Distant sites, difficult if R-sided cardiac chambers enlarged (often fluoroscopic guidance necessary)


•  Insert into introducer maintaining preformed curve (RIJ approach: Concave-cephalad)


•  Once PAC enters RV, a clockwise quarter turn moves tip anteriorly (allows easier passage into PA)


•  After inserting PAC to 20 cm mark (30 cm mark if femoral route used), inflate balloon with air (1–1.5 mL)


•  Always inflate balloon before advancing & always deflate balloon before withdrawal


•  While advancing, waveforms will be observed (distal lumen pressure monitoring):


• RA ≈ 25 cm (RIJ)


• RV ≈ 30 cm (↑ systolic pressure than RA, absence of dicrotic notch)


• PA ≈ 40 cm (↑ diastolic pressure, ↓ systolic pressure)


• PCWP ≈ 45 cm (some damping & ↓ pressure with occlusion of PA)


•  Obtaining pulmonary capillary wedge pressure


• Disconnect breathing circuit


• Determine volume of air in balloon required to obtain a PCWP waveform (volume < half balloon max. may indicate tip too far distal)


• Read PCWP (correlates with LVEDP ≈ 4–15 mm Hg is normal)


• Reconnect breathing circuit, deflate balloon, observe PA waveform return


• PA diastolic pressure usually correlates well with PCWP pressure (should be used as parameter to assess left ventricular filling)


• Withdraw PAC slightly (1–2 cm) to prevent PA rupture from distal tip migration


• Secure catheter sleeve once PCWP is obtained (assure that PCWP pattern is reproducible before removing sterile field)


•  Troubleshooting a coiled/knotted catheter:


• Prevention: Withdraw PAC slowly to ↓ risk of knotting catheter upon itself


• Use fluoroscopy if necessary to remove a knot


• Remove PAC & introducer as one unit if unable to release a knot


• Obtain a CXR to check PAC position


Complication: PA Perforation


•  Predisposed when no wedge pattern evident after deep insertion


•  Circumstances that predispose to PA perforation: Papillary muscle ischemia, mitral stenosis or regurgitation, pulm. HTN, intrapulmonary shunting, LV failure


•  Caution if no definitive wedge pattern is observed (repeated attempts to advance PAC may lead to PA perforation)


•  Coiling or actual false-negative wedging may occur & predispose to PA rupture


DECOMPRESSION OF A PNEUMOTHORAX (NEEDLE THORACOSTOMY)


Indication


•  Tension pneumothorax (symptoms: Hypotension, ↓ SpO2, ↓ breath sounds & tympanic to percussion on affected site; deviated trachea & mediastinum on CXR)


Technique


•  Insert large bore cannula or needle into 2nd intercostal space on midclavicular line


•  Release pressure in pleural cavity (converts tension pneumothoraxsimple pneumothorax)


•  Subsequent chest tube insertion usually required to treat pneumothorax


Complications


•  Lung laceration (esp if no tension pneumothorax present)


•  Reaccumulation of air in pleural space (may be undetected if needle thoracostomy becomes dislodged)


INSERTION OF A NASOGASTRIC TUBE (NGT)


Indication


•  Decompression & emptying of stomach (after RSI, prior to laparoscopy, GI surgery)


•  Aspiration of gastric fluid (lavage to detect intragastric blood in the setting of GI bleed)


•  Tube feeding


•  Drug administration


Contraindications


•  Base of skull fractures, severe facial fractures (esp to nasal bones)


•  Obstructed esophagus or airway


Technique


•  Measure tube length (tip of pt’s nose to ear & down to xiphoid process)


•  Lubricate end of plastic tube being inserted into anterior nares


•  Advance tube through nasal cavity & into throat


•  Pass pharynx rapidly with gentle continuous pressure to go into stomach
(if pt awake, encourage patient swallowing)
(if pt asleep, consider use of laryngoscope to visualize entry into esophagus)


•  Confirm placement by CXR (safest), aspiration or injecting air (stomach auscultation)


Complications


•  Malplacement (endotracheal, intracranial)


•  Esophageal perforation


•  Pulmonary aspiration, pneumothorax


•  Nose erosion/bleeding, sinusitis, sore throat


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Aug 28, 2016 | Posted by in ANESTHESIA | Comments Off on IN ANESTHESIA

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