Lecture 1: PreOp Assessment AL Flashcards

1
Q

Why is the preop assessment performed?

Regulatory Requirements:

A

 AANA Standard of Care (see document)
https://www.aana.com/docs/default-source/practice-aana-com-web-documents(all)/standards-for-nurse-anesthesia-practice.pdf

 American Society of Anesthesiologists - mandated

 The Joint Commission on Accreditation of Healthcare Organizations - mandated

 Centers for Medicaid and Medicare-reimbursement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

AANA Standard of Care:

A

Standard 1: Patient’s Rights
Standard 2: Preanesthesia Patient Assessment and Evaluation
Standard 3: Plan for Anesthesia Care
Standard 4: Informed Consent for Anesthesia Care and Related Services
Standard 5: Documentation
Standard 6: Equipment
Standard 7: Anesthesia Plan Implementation and Management
Standard 8: Patient Positioning
Standard 9: Monitoring, Alarms
Standard 10: Infection Control and Prevention
Standard 11: Transfer of Care
Standard 12: Quality Improvement Process
Standard 13: Wellness
Standard 14: A Culture of Safety

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

AANA Standard of Care

Standard 9: Monitoring, Alarms

A
Oxygenation 
Ventilation 
Cardiovascular
Thermoregulation
Neuromuscular
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Goals of Preoperative Evaluation:

***oral

A

 reduce patient risk and morbidity a/w surgery and anesthesia
 prepare the patient medically and psychologically
 promote efficiency
 reduce costs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Components of Preoperative Evaluation:

A

 Patient medical history (chart review + history taking)  Physical exam
 Medications/ Allergies
 Laboratory testing/ Diagnostic testing
 Medical consultation (if indicated)
 ASA-Physical Status assignment
 NPO status (fasting status and aspiration risk)
 Formulation of anesthetic plan
 Discussion of plan (educate and decrease anxiety)
 Informed consent
 Documentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where is this assessment performed?

Preoperative Evals/Assessment:

A

Presurgical testing centers (early testing)

Hospitals

  1. OR settings
  2. critical care units
  3. specialty departments

Outpatient centers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When is the Preop Eval performed?

Optimal Situation =

A

Preoperative Clinic Visit ~ 1 week preop
 Patient interview
 Physical examination
 Develop anesthetic plan
 Promotes patient teaching & anxiety reduction
 Allows time to schedule appointments with medical consultants and complete required pre-operative diagnostic testing
 Obtain informed consent prior to operative day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Who Requires Early Preoperative Assessment?

A

Examples:
 Angina, CHF, MI, CAD, poorly controlled HTN
 COPD/severe asthma, airway abnormalities, home O2 or ventilation
 IDDM, adrenal disease, active thyroid disease
 Liver disease, end-stage renal disease
 Morbid obesity, symptomatic GERD
 Severe kyphosis, spinal cord injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

OR Schedule:

A
 Demographics- name, age, gender
 Procedure + diagnosis
 Length of procedure + position
 Surgeon(s)
 Type of anesthesia (double check)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Chart Review:

A
 Demographics- name, age, sex 
 Diagnosis/ Procedure 
 Surgical Consent 
 Prior H&P (from surgeon or internist) 
 Nursing notes 
 Patient questionnaire 
 Results of Laboratory Tests 
 EKG, PFTS, X-Ray, Etc. 
 Vital Signs 
 Medication List 
 Allergies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Do NOT forget about the…..?

A

Patient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

If inpatient, may also look at:

A
 progress notes
 medication administration records
 nursing notes
 consult notes
 test results
 ***old anesthesia records (complications noted?)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Are there additional benefits of the preop assessment?

A

YES! Make pt feel comfy!

Establishment trusting relationship!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Preoperative Interview:

A

 Introduction- title (SRNA, CRNA, MDA) & role
 Confirmation- pt. ID, dx, procedure (surgical site)
 Education- type of anesthetic, IV insertion, urinary cath, airway instrumentation, monitors, postop care
 Establishment- trusting relationship

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The Preoperative Interview: History

A
Review of systems (subjective!):
▪ CNS/NM
▪ Cardiac
▪ ENT
▪ Pulm
▪ Vascular/HTN
▪ Endocrine
▪ GI/hepatic
▪ Renal
▪ Hematologic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The Preoperative Interview: Medications

A

Allergies

  • **what happened
  • including latex type rxn

Prescription meds

  • DC’d? When?
  • Taken this AM?

OTC (ASA, NSAIDs)

Herbals (2 weeks!)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Preoperative management of Medications (BOX 31.15):
1. Antihypertensives medications

*instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise

A

Continue on the day of surgery,

EXCEPT for ACEIs and ARBs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Preoperative management of Medications (BOX 31.15):
2. Cardiac medications (e.g. BBs, digoxin)

*instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise

A

Continue on the day of surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Preoperative management of Medications (BOX 31.15):
3. Antidepressants, anxiolytics, and other psychiatric medications

*instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise

A

Continue on the day of surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Preoperative management of Medications (BOX 31.15):
4. Thyroid medications

*instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise

A

Continue on the day of surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Preoperative management of Medications (BOX 31.15):
5. Oral contraceptive pills

*instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise

A

Continue on the day of surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Preoperative management of Medications (BOX 31.15):
6. Eye drops

*instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise

A

Continue on the day of surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Preoperative management of Medications (BOX 31.15):
7. Heartburn or reflux medications

*instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise

A

Continue on the day of surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Preoperative management of Medications (BOX 31.15):
8. Opioid medications

*instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise

A

Continue on the day of surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Preoperative management of Medications (BOX 31.15): 9. Anticonvulsant medications *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Continue on the day of surgery
26
Preoperative management of Medications (BOX 31.15): 10. Asthma medications *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Continue on the day of surgery
27
Preoperative management of Medications (BOX 31.15): 11. Corticosteroids (oral and inhaled) *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Continue on the day of surgery
28
Preoperative management of Medications (BOX 31.15): 12. Statins *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Continue on the day of surgery
29
Preoperative management of Medications (BOX 31.15): 13. Aspirin *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Continue aspirin in pts w/ prior percutaneous coronary intervention, high-grade IHD/CAD, and significant CVD. Otherwise, discontinue aspirin 3 DAYS before surgery.
30
Preoperative management of Medications (BOX 31.15): 14.1 P2Y12 inhibitors...Antiplatelet medications (e.g. clopidogrel, ticagrelor, prasugrel, ticlopidine) Patients having cataract surgery w/ topical or general anesthesia: *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Patients having cataract surgery w/ topical or general anesthesia do not need to stop taking thienopyridines.
31
Preoperative management of Medications (BOX 31.15): 14.2 P2Y12 inhibitors...Antiplatelet medications (e.g. clopidogrel, ticagrelor, prasugrel, ticlopidine) If reversal of platelet inhibition is necessary: *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
If reversal of platelet inhibition is necessary, the time interval for discontinuing these medications before surgery is: 5-7 days for clopidogrel and ticagrelor, 7-10 days for prasugrel, and 10 days for ticlopidine.
32
Preoperative management of Medications (BOX 31.15): 14.3 P2Y12 inhibitors...Antiplatelet medications (e.g. clopidogrel, ticagrelor, prasugrel, ticlopidine) Pts with stents: *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Do NOT discontinue P2Y12 inhibitors in pts who have drug-eluting stents until they have completed 6 mo of dual antiplatelet therapy, unless pts, surgeons, and cardiologists have discussed the risks of discontinuation. The same applies to pts w/ bare metal stents until they have completed 1 month of dual antiplatelet therapy.
33
Preoperative management of Medications (BOX 31.15): 15.1 Insulin (short-acting.... e.g. regular) *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
For ALL pts, discontinue ALL short-acting (e.g. regular) insulin on day of surgery (unless insulin is administered by cutaneous pump).
34
Preoperative management of Medications (BOX 31.15): 15.2 Type 2 Diabetes *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Pts with type 2 diabetes should take none or up to one half of their dose of long-acting or combination (e.g. 70/30 preparations) insulin on the day of surgery.
35
Preoperative management of Medications (BOX 31.15): 15.3 Type 1 Diabetes *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Pts with type 1 diabetes should take a small amount (usually one third) of their usual long-acting insulin dose on the day of surgery.
36
Preoperative management of Medications (BOX 31.15): 15.4 Insulin pump *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Pt with an insulin pump should continue their basal rate only.
37
Preoperative management of Medications (BOX 31.15): 16. Topical medications (e.g. creams and ointments) *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Discontinue on the day of surgery
38
Preoperative management of Medications (BOX 31.15): 17. Non-insulin antidiabetic medications *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Discontinue on the day of surgery (exception: SGLT2 inhibitors should be discontinued 24 hours before elective surgery)
39
Preoperative management of Medications (BOX 31.15): 18. Diuretics *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Discontinue on the day of surgery (exception: thiazide diuretics taken for hypertension, which should be continued on the day of surgery)
40
Preoperative management of Medications (BOX 31.15): 19. Sildenafil (Viagra) or similar drugs *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Discontinue 24 hrs before surgery
41
Preoperative management of Medications (BOX 31.15): 20. COX-2 inhibitors *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Continue on the day of surgery unless the surgeon is concerned about bone healing
42
Preoperative management of Medications (BOX 31.15): 21. NSAIDs *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Discontinue 48 hrs before the day of surgery
43
Preoperative management of Medications (BOX 31.15): 22. Warfarin (Coumadin) *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Discontinue 5 days before surgery, | EXCEPT for pts having cataract surgery w/o a bulbar block.
44
Preoperative management of Medications (BOX 31.15): 23. MAOIs *instruct pts to take these medications with a small sip of water, even if fasting, unless stated otherwise
Continue these medications and adjust the anesthesia plan accordingly.
45
The Preoperative Interview
Past surgical hx (including previous anesthetics): - complications - family hx complications - obstetrical deliveries ``` Other: ETOH use? Drug abuse? Tobacco use? Females - LMP? Pain? NPO status Height/weight ```
46
The Preop Interview: Physical Exam
 General Impression, mental status (document!)  Airway-regardless of plan (ALWAYS)  Heart (ALWAYS)  Lungs (ALWAYS)  CNS/PNS  Vital signs (current by NA or RN, document)  Height/weight (current by NA or RN, document)
47
Mallampati Classification
``` PUSH = Pillars Uvula Soft Palate Hard Palate ``` ``` I = PUSH II = USH III = SH IV = H ```
48
“Although by itself, the Mallampati class has a low____ positive predictive value in identifying patients who are difficult to intubate. Therefore a _____________ approach to predicting intubation difficulty has proven to be more helpful”
“Although by itself, the Mallampati class has a low positive predictive value in identifying patients who are difficult to intubate. Therefore a multifactorial approach to predicting intubation difficulty has proven to be more helpful”
49
Additional difficult airway predictive tests (also review slide 35):
1. thyromental distance: <6.5cm or 3 fingers 2. interincisor distance: <3cm or 2-3 fingers 3. Atlanto-occipital function: <23deg, average 35deg 4. mandibular protrusion test (ULBT) 5. hyomental distance (mandibulohyoid): <4cm or 2 fingers 6. neck circumference (>16cm
50
Mandibular protrusion test(ULBT)
Class A: Lowers past uppers (bite upper lip) Class B: Lowers equal uppers Class C: Lowers cannot reach uppers (bad)
51
Size of Neck Average neck size:
male = 15- 16 inches (38-40 cm) women = 13-14 inches (33-35 cm) 17 inches or > 40 cm neck size – 5% chance of difficult airway *Increases 1.3% for every 1 cm increase in neck size
52
Physical Exam: Prayer Sign
Joint stiffening ~ airway stiffening?
53
Physical Exam: Heart
```  Auscultation  Rate  Rhythm  Murmurs  Bruits (carotid)  Extremity pulses  APTM ```
54
Physical Exam: CV
Bruits (carotid) Extremity pulses Extremity edema
55
Physical Exam: Lungs
 Inspection  Auscultation  Percussion  Palpation
56
Physical Exam: Neurologic/ Musculoskeletal System | *Extent of neuro exam really depends on baseline deficits, disease or surgical procedure
 Motor – gait, grip strength, ROM, ability to hold arms forward, etc.  Sensory – distinction of vibration, pain, light touch along dermatomes  Muscle reflexes – deep, superficial, and pathologic  Cranial nerve abnormalities  Mental status  Speech
57
End Target Organ Damage
Eye ball vessels CXR Cardiomegaly Wide QRS Proteinuria
58
“2012 ASA Practice Advisory for Preanesthesia Evaluation states that:
routine preoperative tests do not make an important contribution to preanesthetic evaluation of an asymptomatic patient” (Hata & Hata, 2017)
59
Preop testing should be SELECTIVELY ordered based on: SELECTIVE testing:
Preop testing should be SELECTIVELY ordered based on: - patient’s medical history and physical exam - planned surgery - expected intraoperative blood loss SELECTIVE testing: expedites patient care reduces healthcare cost improves delivery of perioperative meds
60
More tests are better, right? Will the results change the INTRAOPERATIVE management of this patient? If so, then.....
WRONG! TEST!!!
61
Factors that contribute to nonselective ordering: • Surgeons and PCPs— often no diagnostic focus anesthesia providers “require them” • Routine screening for disease states • Diagnostic baseline • Personal habit • Medicolegal necessity “not to miss anything”
• Surgeons and PCPs— often no diagnostic focus anesthesia providers “require them” • Routine screening for disease states • Diagnostic baseline • Personal habit • Medicolegal necessity “not to miss anything” * the more we test the more we are liable for
62
Pretesting is partially based on invasiveness of surgery: | ❑ Minimally Invasive (skin lesion excision)
little tissue trauma, minimal blood loss (<500 mL)
63
Pretesting is partially based on invasiveness of surgery: | ❑ Moderately Invasive (inguinal hernia, tonsillectomy, knee arthro)
modest disruption of normal physiology anticipate some blood loss (500-1500 mL) may need invasive monitors and/or ICU
64
Pretesting is partially based on invasiveness of surgery: | ❑ Highly Invasive (vascular sx, TURP, TJR, rad neck dissect, lung)
significant disruption of normal physiology blood loss >1500 mL commonly require transfusion and ICU care
65
What labs/tests and when?
``` What labs/tests and when?  Institutional policy  Current expert organization guidelines i.e. ACC/AHA guidelines  Anesthesia provider judgment  Table 31.18 ```
66
What labs/tests and when? | Table 31.18: HF
EKG | CXR (consider)
67
What labs/tests and when? | Table 31.18: HTN
EKG CXR (consider) Electrolytes Creatinine
68
What labs/tests and when? | Table 31.18: Chronic AFib
EKG | Drug Levels
69
What labs/tests and when? | Table 31.18: COPD
EKG CXR (consider) CBC Drug Levels
70
What labs/tests and when? | Table 31.18: Diabetes mellitus
EKG Electrolytes Creatinine Glucose
71
What labs/tests and when? | Table 31.18: Renal Disease
CBC Electrolytes Creatinine
72
What labs/tests and when? | Table 31.18: Morbid obesity
EKG CXR (consider) Glucose
73
``` CXR?  Assessment of perioperative risk = ?  Therefore, should or should not be ordered routinely  Decision based on?  Indications = ? ```
questionable should NOT based on abnormalities identified during the preop assessment (ie, rales, SOB intercostal retractions, deviated trachea) severe COPD, suspected pulmonary edema, pneumonia, susp mediastinal masses or PE
74
What about CXR in smokers?
if Significant smoking history = 20 pack years | 20 pack yrs = 2 packs / day X 10 years
75
RECOMMENDATIONS for PREOP 12 LEAD ELECTROCARDIOGRAM:  CLASS IIA RECOMMENDATION  Class IIB  Class III
 CLASS IIA RECOMMENDATION: It is Reasonable to Perform the Procedure for patients with IHD, significant arrhythmia, PAD, CVD, or significant structural heart disease (except if undergoing low-risk surgical procedures)  Class IIB: The Procedure may be Considered for asymptomatic pts w/o known coronary heart ds, except for those undergoing low-risk surgical procedures  Class III: The Procedure Should Not Be Performed Because it is Not Helpful for asymptomatic patients undergoing low-risk surgical procedures
76
Consults? Avoid the terms: Ask specific questions:
Avoid the terms: “cleared for surgery” or “cardiac clearance” Ask specific questions: “Is this patient able to undergo robotic prostatectomy?”
77
NPO Status: Based on CURRENT ASA guidelines that balance risk factors of fasting with pulmonary aspiration risk  _ hours for clear liquids all patients  _ hours breast milk  _ hours formula or solids; light meal  _ hours heavy meal fried or fatty food Follow your institutions policy however! * note: some clinicians remain skeptical and use more conservative guidelines NPO 6-8 hours etc.
 2 hours for clear liquids all patients  4 hours breast milk  6 hours formula or solids; light meal  8 hours heavy meal fried or fatty food
78
Other NPO Status considerations:
* Age extremes <1 yr or >70 yr * Ascites (ESLD) * Collagen vascular disease, metabolic disorders (DM, obesity, ESRD, hypothyroid) * Hiatal Hernia/GERD/Esophageal surgery * Mechanical obstruction (pyloric stenosis) * Prematurity * Pregnancy * Neurologic diseases * Having eaten food or non-clear drinks * HIV/Lipodystrophy
79
ASA Physical Status Classification I- normal, healthy patient; no systemic disease II- mild systemic disease, well controlled, no functional limitation III- severe systemic disease, functional limitations IV- severe systemic disease that is a constant threat to life V- moribund patient, not expected to survive with or without the surgical procedure VI- patient declared brain dead whose organs are being harvested for donation E- emergency operation required
I- normal, healthy patient; no systemic disease II- mild systemic disease, well controlled, no functional limitation III- severe systemic disease, functional limitations IV- severe systemic disease that is a constant threat to life V- moribund patient, not expected to survive with or without the surgical procedure VI- patient declared brain dead whose organs are being harvested for donation E- emergency operation required (added to any above) I- you aint got shit II- you got shit but its controlled III- you got shit and it aint controlled IV- you got shit that bout to kill ya V- if yo shit makes it w/ or w/or surgery, I be like wow VI- yo shit going to someone else
80
ASA PS Class Examples: II
II- mild systemic disease, well controlled, no functional limitation ``` Current smoker social drinker preggers obese (30< BMI<40) well-controlled DM/HTN mild lung disease ```
81
ASA PS Class Examples: III
III- severe systemic disease, functional limitations ``` One or more moderate to severe diseases poorly-controlled DM/HTN COPD morbid obesity (BMI>40) active hepatitis alcohol dependence or abuse implanted pacer moderate EF reduction ESRD undergoing regular dialysis premature infant PCA < 60 weeks Hx (>3mo) of MI, CVA, TIA, or CAD/stents ```
82
ASA PS Class Examples: IV
IV- severe systemic disease that is a constant threat to life Hx (<3mo) of MI, CVA, TIA, or CAD/stents ongoing cardiac ischemia or severe value dysfunction severe EF reduction sepsis DIC ARD or ESRD not undergoing regular dialysis
83
ASA PS Class Examples: V
V- moribund patient, not expected to survive with or without the surgical procedure ``` ruptured abd/thoracic aneurysm massive trauma intracranial bleed with mass effect ischemic bowl in the face of significant pathology or multi organ/system dysfunction ```
84
How long is a typical preoperative anesthetic assessment on a same day surgery patient?
10 min?
85
How many care plans do we need at minimum?
A & B ``` A = ET and GA B = back up plan ```
86
Formulate Anesthetic Plan:
``` Preoperative care Intraoperative care  Type of Anesthesia  Drugs  Monitors  Airway  Positioning  Intraoperative monitoring Postoperative care ```
87
Anesthesia Plan Components:
```  Drug plan/ anesthetic technique  Airway plan  Ventilation plan  Fluid plan/ IV access plan  Monitoring plan  Positioning plan  Other considerations ```
88
The Anesthetic Plan will be influenced by:
```  Current physical status  History and physical assessment  Co-existing diseases  Airway assessment/ Difficult airway?  Previous anesthesia complications  Family history of anesthesia problems  Planned surgery ```
89
Choices of Anesthetic Technique:
``` Initiation of the anesthetic technique may include  General  Regional  Combined General/Regional  MAC  Local ```
90
Intraoperative Fluid Requirements (review slide 83):
``` Maintenance Fluid deficit Blood loss Evaporative loss (3rd space loss) ***Goal-direct fluid management ```
91
Patient Preparation/Information the Patient Requires from an Anesthesia Professional:
 Discuss choices of anesthetic technique (consent) ***Verbal & Written consent  Explain IV catheter  Describe use of local anesthetics, medications, fluids  Discuss airway management plan  Explain monitors- placement, purpose  Discuss postoperative recovery  Discuss pain management plan
92
Informed Consent:
``` Informed Consent:  Explanation of the planned anesthetic  Explanation of options available  Risks and Benefits  Pt. understanding & cooperation  Without consent – Assault and Battery  Minors – consent from parents or guardian  Signature of pt. & witness ```