1 / 50

PICU Primer II

Kevin M. Creamer M.D. Pediatric Critical Care Walter Reed AMC. PICU Primer II. Physiology Hypoxia / Hypoxemia ABG’s and Acidosis Sodium and H 2 O metabolism Hemodynamics and Cardiopulmonary interactions. ICU Care Postoperative issues Mechanical Ventilation Common Problems

quasar
Download Presentation

PICU Primer II

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Kevin M. Creamer M.D. Pediatric Critical Care Walter Reed AMC PICU Primer II

  2. Physiology Hypoxia / Hypoxemia ABG’s and Acidosis Sodium and H2O metabolism Hemodynamics and Cardiopulmonary interactions ICU Care Postoperative issues Mechanical Ventilation Common Problems Head trauma Toxicology The Primer Outline

  3. Postoperative Issues • Borrowed in part from Akron syllabus • Know the surgery • what can you expect from a posterior spinal fusion is different than a tracheal reconstruction • Know the patient • Age, PMHx, Syndromes • Be there when they get out of the OR

  4. Postoperative Evaluation • ABC’s • Look at the breathing pattern • Listen to the chest--breath sounds, stridor? • Listen to the heart--gallop, murmur? • Feel the pulses--strong, weak, thready? • Cap refill?, Extremity warmth?

  5. The Anesthesia Report • “History of present illness” for surgical patients • Difficulties with induction or intubation? • Drugs used during case • Regional techniques employed? • Extubation-problems? • Vital signs- BP, HR, RR, SaO2, temp • Patients are frequently cold!

  6. The Anesthesia Report • Ventilation parameters/difficulties • Fluids--ins and outs • Any “events”? • Lines and tubes

  7. Intraoperative Fluids • Pediatrician: “Why do they always get so much fluid?” • Anesthesiologist: “Because they need it” • maintenance + replacement of “third space” losses • “third space” losses can be 15 cc/kg/hr + replacement of 3 X blood loss

  8. Anesthesia and Fluid Balance • General anesthesia produces vasodilation and some decrease in myocardial contractility. • Increased intrathoracic pressure, and stress response to surgical stimulus, may lead to increased ADH production and decreased urine output

  9. BLOOD loss and replacement • Blood loss isestimated • Transfusion Criteria - it depends • Check Hct, HR, UOP, pH, ongoing loss, Hemodynamics … • When do you need Component Tx? • after a “massive” transfusion or ( 0.75-3.0 blood volumes)

  10. Blood Products - How much? • PRBCs - 4cc/kg of will Hb 1gm/dl • Platelets - 1unit/5kg will  count by 50000 • FFP - 10 ml/kg round up/down to closest unit • Cryoprecipitate - 1bag/every 5-10kg Surgeons get extremely persnickety if you transfuse THEIR patient without letting them know ahead of time!

  11. The Surgical Report • Since we are not surgeons we need to know what they anticipate and worry about • Amount of pain • Third spacing • Possible complications • Their wish list: • Extubate tomorrow, MRI at midnight • Special meds: antibiotic and stress ulcer prophylaxis

  12. The Surgical Report • What to touch and not to touch? • NG, foley, chest tube, rectum, etc. • Check all their orders for appropriate dosing and fluids • mg/kg/dose is not in surgical vocabulary • Who is in Charge? (Us vs. Them) • Surgical POC? • Interface with surgeons before they return to the OR in AM regarding the plan

  13. Assessment of Fluid Balance: • Vital signs (HR/BP) • Urine output • Extremity warmth, CRT • Acid-base status • Occasionally invasive monitoring • Remember the Liver!

  14. Extubation Time? • Adequate airway (edema? ,Leak?) • Maintain oxygenation and ventilation • Neurologically able to protect the airway and maintain adequate drive. • Small/young infants are at increased risk of apnea • Especially if post-conceptual age < 50weeks

  15. Sedation and Analgesia • Analgesia for painful diseases and procedures • Compliance with controlled ventilation and routine intensive care • Sedation for amnesia for the periods of noxious stimuli • Reduce the physiologic responses to stress

  16. Sedation and Analgesia • The idea of titrating drugs to effect--there is no “dose”. • Keep in mind what the “target” response is. • Consider Round-the-clock Tylenol for 24-48 hours as adjunct • First PR dose may be 30-40 mg/kg • Anesthesia service manages Epidurals • Consider a continuous drip

  17. BP: hypotension, H: Histamine, A: Apnea, CWR: chest wall rigidity

  18. Muscle Relaxants • They provide ZERO sedation/analgesia. • Indications (always relative) • Mechanical ventilation where risk of extubation is great, or risk of baro/volutrauma is high • Procedures such as central line placement or biopsy in the intubated patient • Intractable intracranial hypertension (IF ICP being monitored)

  19. Problems with Blockade • Fluid retention • Long term weakness • continuous infusions • most commonly the steroid based NMBs • myopathy associated with Atracurium • consider using cis-Atracurium • Consider Train of Four testing • FREQUNTLY OVERUSED

  20. Questions ? • NEXT UP • Mechanical ventilation This is not the NICU!

  21. Lesson Learned:VALI –Predisposing Factors • High lung Volumes • With high peak pressure and alveolar overdistension • Repeated alveolar collapse and reopening • High inspired oxygen Concentrations • Preexisting lung injury Slutsky Am J Resp CCM, 1999, Dreyfuss Am J Resp CCM 1998

  22. Mechanical Ventilation • Do’s and Don’ts • Avoid Overdistension and High Pressure by limiting Tv • Avoid Hyperoxic Lung damage by turning FIO2 down (Sat 90% okay) • Avoid cyclic collapse by using PEEP to recruit FRC and keep it above Closing volume • Infant high risk 2° high elastic recoil and complaint chest wall

  23. Open Lung Strategy

  24. Getting Started (Parameters)

  25. Getting Started (Mode)

  26. Constant vs. Decelerating flow

  27. Getting Started (Settings) • FIO2 - 50%, if sick 100% • It - minimum .5 sec, older kids 1 sec • Rate - age appropriate 15 -30 to start • Tv - 10ml/kg to start • Look / Listen / Ask • PEEP - 4cm, higher if FRC compromised

  28. IT and Time Constants Full equilibration • The time to fill each alveolus is determined by its time constant • TC= Resistance X Compliance • A Short IT decreases TV, or increases PIP

  29. Mechanical Ventilation • First hour • CXR and “Blood Gas” • Watch peak pressures as compliance estimate • PP << 20 ideal • PP 20-30 moderately  compliance • PP >> 30 severely  compliance • PP >> 35 high risk for VALI, DO SOMETHING

  30. Mechanical Ventilation • Change Tv only for inappropriate chest rise or for elevated inspiratory pressures (Don’t WEAN Tv) • Sedation to allow patient - ventilator synchrony (Paralytics aren’t required)

  31. Monitoring adjuncts • Pulse oximeter • End tidal CO2 - can use for Dead space estimate • ABG’s and CBG’s • Calculate Compliance, A-a gradient, Oxygenation Index (OI), check for Autopeep • Graphics - PV and flow-volume loops

  32. Equations • Dead Space = 1 - (EtCO2/PaCO2) • Static Comp. = Tv/ (Pplat- PEEP) • A-a gradient = • (Pb-PH2O) x FIO2 - (PCO2/.8) - PaO2 • OI = (Paw x FIO2 x 100)/ PaO2

  33. When things go wrong • Don’t be a DOPE • Hypoxemia - PEEP to  FRC, to allow FIO2 wean to < 50% • Elevated peak pressures - suction, adopt Permissive hypercapnia, consider changing to pressure mode • Check circuit size • an inappropriately large circuit can gobble up lots of tidal volume

  34. Paw (Area Under Curve )increases with increasing: • PIP, PEEP, TI/TE Ratio, Rate, and Flow PIP Pressure Flow Rate TI PIP PEEP PEEP Time TI TE

  35. Circuit compliance • When using volume ventilation the ventilator circuit or tubing will stretch • Neonatal 0.35 ml / cm H2O • Pediatric 1.4 ml / cm H2O • Adult 2.8 ml / cm H2O • This means the stiffer the lung the more volume is lost in the circuit

  36. Mechanical Ventilation • First day and beyond • Watch for fluid overload • all patients on positive pressure ventilation retain lung water • Assist patient efforts • Pressure support or volume support • Trigger sensitivity (age and disease appropriate) • Treat underlying condition • Feed patient

  37. Weaning • Get condition under control • Stop paralytics (PEEP < 8) • Encourage patient’s efforts •  Rate (slow then fast) • add Pressure support (2/3 P) • Wean PEEP and PS slowly in 1-2 cm H2O increments • Wean FIO2 to 30% if possible

  38. Signs of weaning failure • Increased Work of breathing • fast spontaneous RR • small spontaneous Tv • Increased FIO2requirement • Hemodynamic compromise

  39. Time for Extubation? • Think SOAP • Secretions / Sedation / Spontaneous Tv (>5ml/kg) • Oxygenation <35% • Airway - Maintainable?, Leak? , Steroids? • Pressures - PP <25, PEEP < 5

  40. Extubation success predictors Khan, CCM 1996

  41. Special situations I • Obstructive Diseases • Asthma and RSV Bronchiolitis • Watch for air trapping / breath stacking • Low rate, larger Tidal volume, long Expiratory time • check Autopeep • preserve I-time • Consider Heliox, Ketamine, Halothane

  42. Special situations II • ARDS • Limit Tv accept hypercapnia • Increase PEEP for FRC • Prone positioning •  CaO2 and tolerate lower Sat % • consider High Frequency Oscillatory Ventilation>>> Surfactant>>> Nitric Oxide

  43. Volutrauma 861 patients 6ml/kg vs 12ml/kg Tv ARDS Study Group, NEJM, 2000

  44. Biotrauma Organ Failure • RCT 44 adults with ARDS • TV 7.6 vs. 11.1 • PP 24 vs. 31 cm H2O • At 36° patients in low TV group had significantly lower levels of TNF and IL-1ra in both plasma and BAL fluid Ranieri, JAMA,1999; Ranieri JAMA, 2000

  45. Special situations III • Head Trauma • Avoid Hypercarbia (PCO2 < 35) • Avoid Hypoxemia • PEEP may adversely effect venous return and  ICP • Coughing/gagging extremely bad (Use paralytics)

  46. Special situations IV • HFOV Indications • ARHF with OI > 13 for 6 hours • Contraindicated in High airway resistance,  ICP, unstable hemodynamics • Part of an Open lung strategy with  Mean airway pressure and Tv < dead space

  47. HFOV vs. CMV • Crossover study acute hypoxemic respiratory failure in children • HFOV 17/29 responded, 0/17 died • CMV 10/29 responded, 4/10 died • X-over to HFOV 11/19 survived • X-over to CMV 2/11 survived Arnold, CCM 1994

  48. Ventilation Simulator • Not for the weak of heart

  49. The End Mind what you have learned. Save you it can.

  50. Questions?

More Related