Pulmonary Function

1. Pulmonary Function

3. Anatomy • In utero lung development • Begins-21-28 day gestation • Complete at 16 weeks • Approx. 15-26 divisions

4. Anatomy • True alveoli @ 28 weeks • Continue past birth, with 20 mil @ birth • 300 mil @ 10 yrs (peak) • Lung volume- • 80% air • 10% blood • 10% solid tissue

5. Anatomy • Alveolar-Capillary membrane • 5 Layers- • alveolar epithelium • basement membrane • ground substance • basal membrane • capillary epithelium

6. Anatomy • Bronchi • 23 branches from trachea to alveoli • larger airways lined with ciliated columnar • epithelium • flatten in the alveoli • mucociliated esculator

7. Anatomy • Alveoli- • Type I • cover 90 % • make up 50 % • gas exchange • Type II • cover 10% • make up 50 % • lipoprotein- surfactant- decrease surface • tension

8. Anatomy • Bony Thorax • 12 ribs • 1-5 attach to sternum • 6-10 fuse to costal cartilage arch • 11-12 free floating • Lobe sections • R- 3 lobes, major & minor fissure 10 segs • L- 2 lobes, major fissure 8 segs

9. Anatomy • Lymphatics • generally drain to ipsilateral hilum • from intralobar nodes • mediastinal nodes drain cephadal • exception- LLL may > R mediastinal • Nerves • none in parenchyma • rich in parietal pleura (painful chest tube)

10. Anatomy • Blood supply • 2 fold • pulmonary artery • bronchial arteries off aorta

11. Pulmonary Function Tests • Pre Operative Evaluation • Measures • lung volumes • elasticity • recoil • complaince

12. Pulmonary Function Tests • Blood Gases • pO2 • pCO2 >43-45 severe functional loss • i.e. > 50 % • Volume measurements • FEV1 normal > .8L ^ risks if less • FEV1/FVC ratio • obstructive- ratio low • restrictive- ratio normal (both reduced)

13. Pulmonary Function Tests • Exercise Testing • DL CO- measures CO from alveoli to • hemoglobin (affinity >200 times) • <50% high risk of failure • VO2-(max O2 consumption) • <15 ml/min/kg high risk • Vent/Perfusion scan functional segments • Clinical- stair climb 1,wedge 2,lobe 3,lung

14. Surgical Incisions • Types • Post. Lat • Axillary • Ant. Lat • Median sternotomy • Thoracoabdominal • Clamshell • VATS • Up to one quarter functional loss

15. Preoperative Risks • Increased • age • smoking • COPD • asthma • obesity • diabetes • poor nutritional state

16. Preoperative Treatment • Smoking cessation- >2 wks, ideal > 4-6 wks • Bronchodialators • Antibiotics- Bronchitis • Steriods- short term • Incentive Spirometry training • DVT prophylaxis • Sub-q heparin or equal • Compression device • Consider- epidural, nerve blocks, PCA’s

17. Lung Cancer • General • 173,000 new yearly • 14% all cancer • 28% all cancer deaths (most freq) • decrease mortality in men 1991-1996 • increase in women since 1987 > breast CA • lag in smoking cessation

18. Lung Cancer • Survival • Overall 5 year 14% • Regional disease 20 % • Distant disease 2 % • Only 15% localized at time of dx • Stage I & II– generally surgery • Stage IIIA and up—generally XRT, chemo

19. Lung Cancer • Etiology • cigarettes • alcohol • environmental • asbestos, radon,nickel, radiation, • arsenic, chromium, air pollution, • second-hand smoke

20. Lung Cancer • Pathology • R>L secondary to 55% lung on R • Stages • proliferation • atypical nuclei • stratification • squamous metaplasia • CA in situ • invasive CA

21. Lung Cancer • Types • Adeno CA 45% • peripheral, early mets, mucous cells • Bronchoalveolar CA <5% • subtype of adeno, best prognosis • Squamous Cell CA 30% • centrally located, later mets, local invade

22. Lung Cancer • Types (cont) • Large Cell CA 10% • peripheral, early mets • Small Cell CA 20% • central, aggressive, early mets bone, • brain, chemo (!), oat cell

23. Lung Cancer • Metastasis • typically, lobar>hilar>mediastinal (ipsilat) • exception, LLL>contralateral mediastinum • hematologous spread • liver, adrenals, bone, brain, kidneys, lung

24. Lung Cancer • Detection • local symptoms • cough, pnemonia, hemoptysis, rib pain, • nerve involvement • distant symptoms • weight loss, bone pain, neurologic, • paraneoplastic,

25. Lung Cancer • Staging • TNM • adopted 1986 • revised 1997

26. Lung Cancer • Special Circumstances • Superior Sulcus CA • Solitary pulmonary nodule • overall 33% CA • risk roughly age of patient • Molecular Markers • poor survival-DNA aneuploidy; • oncogenes KRAS, Her 2, p53 mutation

27. Respiratory Failure • Clinical Assessment • Distress • >24 breaths/min • accessory mm usage • color • O2 content difficult to tell • Pulse Ox • sat 90% approx pO2 of 60

28. Respiratory Failure • Ventilatory Settings • Tidal Volume 12-15 ml/kg • PEEP +5 (starting) • Rate 10-12 • Mode IMV • O2 % depends

29. Respiratory Failure • Ventilator Weaning • pO2 > 70 • stable BP • Cause corrected • NIF > 30 • RR < 24 • pH > 7.35 • pCO < 50

30. Respiratory Failure • Ventilators • + pressure vents 1950’s Scandinavia • polio • Excellent support • Negatives • decrease venous return • ^ dead space • ^ work of breathing • ^ venous admixture

31. Respiratory Failure • Ventilators • favor flow to nongravity dependent • portions of lung, ^ shunt • O2 deficits not correctable with PPV • alone • Fighting the vent • hypercarbia, acidemia, CNS problems, • low O2, pain, anxiety

32. Respiratory Failure • Ventilator Modes • PPV deliver TV without ^ MAP • large TV- dec deadspace,atelectasis • Control Mode Ventilation • frequency and depth independent of • patient’s response • Assist Control Mode • initiates breath whenever preset limit • is hit by patient

33. Respiratory Failure • Ventilator Modes (cont) • Intermittent Mandatory Ventilation (IMV) • PPV independent of patient • no impedence to spontanous breath • + gas flow • SIMV • synchronized to patient • assist control w/ spontanous ventilation • ^ work of breathing, demand flow