hypoxia, respiratory failure and altered mental status

Hypoxia, Respiratory Failure and Altered

Mental Status

Alicia M. Mohr, MDSurgical Fundamentals Session 2

July 21, 2006

http://www.mamashealth.com/images/lungs1.gif

Objectives• To learn a logical method for determining the

nature of respiratory failure and its treatment• To determine if a patient requires intubation and

ventilation• To learn the differential diagnosis and treatment

of altered mental status

History and Physical Exam Diagnosis Operation performed Co-Morbidities Age

Chest X-rayLab Electrolytes Arterial Blood Gass

Pulse Oximetry

Sa02 > 90%

Sa02 < 90%

Remains agitatedand risk for withdrawal(alcohol +/or drug)

May sedate withShort-acting benzodiazepine or haldol

Step 1Assess Airway

Step 2

Step 3Assess Circulation

Intubated

Not intubated

ETT good position

Check CXR(go to step 2)

Re-intubate

intubate

Hemodynamically stable

Assess Breathing

Hemodynamicallyunstable with breath sounds

Check CXR, ABG

Tubethoracostomy

Pulses absent ACLS protocol

Pulses present Assess cardiacstatus- ie.arrythmias

Labs & ABG normal

ETTdislodged

Mini-neuro examReview chart for medications

Consider need for CTH

Call for Altered Mental Status

Desaturation or Respiratory distress

ASSESS PATIENT

History

History

• Can’t catch my breath• Lightedheadedness• Usually acute onset• Minimal symptoms

Physical Exam Findings

Physical Exam Findings• Tachypnea• Dyspnea• Retractions• Nasal flaring• Grunting• Diaphoresis• Tachycardia• Hypertension

• Altered mental status Confusion Agitation Restlessness Somnolence

• Cyanosis (need 5mg/dl of unoxygenated blood)

Case Study #159 year old man underwent a Whipple two days ago. You are called because he developed a sudden onset of dyspnea and he desaturated.His temp is 37.3o, his HR is 120, RR 24 and BP 80/50.He is anxious with decreased breath sounds at bilateral bases.

A - Airway

B - Breathing

C - Circulation

Oxygen delivery to tissues

Carbon dioxide

removal from tissues

Assess, change, reassess

Case Study #1Signs of respiratory distressNasal flaringSternal retractionsTripodingUse of accessory musclesTachypneaCyanoticAnxiety, restlessness

http://www.emedicine.com/med/images/49574957cyanosis1.jpg

Case Study #1• His CBC and lytes are normal• ABG pH 7.45 PaCO2 28 mmHg PaO2 72 mmHg• CXR shows mild left lower lobe atelectasis

Indications for Intubation

Indications for Intubation1. Airway protection

Loss of gag reflex, GCS <8Massive facial trauma

2. Failure to ventilateIncreased work of breathingPaCO2 > 55 mm Hg

3. Failure to oxygenateHypoxemia or PaO2 < 60 mm Hg Severe metabolic acidosis or shockNeed for bronchopulmonary toilet

•The decision to intubate or not intubate a patient can be a life or death decision

•It should not be taken lightly!

•However, most times you will ask yourself-’Have you ever regretted intubating a patient?’

•The most likely response is that you have regretted NOT intubating a patient

•IF YOU THINK ABOUT INTUBATING A PATIENT YOU SHOULD PROBABLY DO IT!

Indications for Intubation

Establish IVPreoxygenate patient

Administer etomidate 0.3 mg/kg IVAdminister succinylcholine 1.5 mg/kg IV

Apply cricoid pressure

INTUBATE

Auscultate bilaterally to verify tube placementUse CO2 detector to assure tube placement

Secure endotracheal tube

Rapid Sequence Intubation

Do not release cricoid pressure until cuff inflated and tube placement verified

CAVEAT: For most emergent intubations medications are not required or not available!

Case Study #1• His CBC and lytes are normal• ABG pH 7.45 PaCO2 28 mmHg PaO2 72 mmHg• CXR shows mild left lower lobe atelectasis

Pathophysiology of

Respiratory Failure

Due to mismatch of ventilation and

perfusion in lung units



Pulse Oximetry

Sa02 > 90%

Sa02 < 90%



Step 1Assess Airway

Step 2


Intubated

Not intubated

ETT good position


Re-intubate

intubate


Assess Breathing


Check CXR, ABG

Tubethoracostomy



Labs & ABG normal

ETTdislodged





ASSESS PATIENT

Case Study #222 year old man was admitted five days ago after an MVC. He sustained a left rib fractures, a left pneumothorax and a left femur fracture. The nurse states the patient is short of breath.

His temp is 37.1o, his HR is 95, RR 30 and BP 120/70. His saturation on room air is 85%

Differential Diagnosis


• Pneumothorax• Pneumonia• Lobar collapse• Pulmonary embolus

Case study #2• When the situation is not life threatening there is

ample time to perform the necessary diagnostic tests and manuevers

• In a life threatening situation immediate action is necessary to prevent arrest

• For example, if you suspect someone has a tension pneumothorax as a life saving manuever you should perform needle decompression with a 14 gauge angiocath rather than wait for a tube thoracostomy and scalpel, etc.



Pulse Oximetry

Sa02 > 90%

Sa02 < 90%



Step 1Assess Airway


Intubated

Not intubated

ETT good position


Re-intubate

intubate


Step 2Assess Breathing


Check CXR, ABG

Tubethoracostomy



Labs & ABG normal

ETTdislodged





ASSESS PATIENT

Case Study #372 year old man was admitted two days ago after an assault. He sustained an orbital fracture, scalp laceration and a frontal contusion. The nurse states the patient is confused and restless.

Case Study #3What do you want to know?

• Is this a change in his mental status?• Was he just medicated?• Has this happened before?• What are his vital signs?• What is his saturation?

Altered Mental StatusFive major causes:

• Metabolic derangement• Drug toxicity/overdose/withdrawal• Infectious• Strutural abnormality• Psychiatric

Altered Mental StatusMetabolic abnormality

• Rule out hypoxia» Check ABG, saturation

• Rule out hypoglycemia, DKA» Assess blood glucose

• Rule out uremia» Assess urine output, BUN, creatinine

• Rule out hepatic encephalopathy» Check ammonia

• Rule electrolyte abnormalities» Send electrolytes

Altered Mental StatusStructural abnormality

• Assess GCS• Assess for suspected head injury• Assess for focal neurologic deficits• Assess for possible post-ictal state• Emergent CT head

Altered Mental StatusInfectious cause

• Assess for post operative sepsis• Assess risk of meningitis• Assess need for CT

Altered Mental StatusDrug toxicity/overdose/withdrawal

• Assess recent prescribed medications• Assess for potential self prescribed

medications• Check pupils• Check for sweating, agitation, hallucinations• Assess HR and blood pressure• May prescribe narcan or naloxone if OD• May prescribe benzodiazepine if withdrawal

Altered Mental Status

Altered Mental StatusPsychiatric cause

• Assess for hallucinations• Assess for delusions• Mini-neuro exam



Pulse Oximetry

Sa02 > 90%

Sa02 < 90%



Step 1Assess Airway

Step 2


Intubated

Not intubated

ETT good position


Re-intubate

intubate


Assess Breathing


Check CXR, ABG

Tubethoracostomy



Labs & ABG normal

ETTdislodged





ASSESS PATIENT

Case Study #470 year old female had a colon resection five days ago. You are called by the nurse because she is dyspneic.

Her temp is 100o, her RR is 30, her HR is 110, and her BP is 140/90.Her saturation is 95% on a non-rebreather.


• Pneumonia• Lobar collapse• Pulmonary embolus• Aspiration• Sepsis• Pulmonary edema• Congestive heart failure• Myocardial infarction

Case Study #4Causes of post-operative dyspnea

• Rule out pneumonia, atelectasis, collapse, aspiration» Check ABG, saturation, CXR» Assess abdomen, need for NGT

• Rule out sepsis» Assess for fever, abdominal exam, CTA/P

• Rule out pulmonary embolus» Assess leg swelling, duplex, CT chest» Can heparin be started empirically?

• Rule out myocardial infarction» Check EKG, troponin, myocardial enzymes» Can aspirin be given?

• Rule out fluid overload, CHF» Listen to lungs, assess fluid balance» Check home medications» Give diuretic

Case Study #4Does this patient need to be moved to monitored bed or

ICU?• Does this patient require intubation now?• May this patient need to be intubated in the next

few hours?• How likely is it that the patient is having an MI?• Is the patient having an arrythmia?• Does the patient need invasive monitoring?• How likely is it that the patient is going to

decompensate?• How likely is it that I am going to be presenting this

at M&M?

Criteria for ICU assessment

Threatened airway Respiratory arrest

Respiratory rate >30 or <8 breaths / min Oxygen saturation <90% on >50% oxygen

Cardiac arrest Pulse rate <60 or >140 beats / min Systolic blood pressure < 90 mmHg Sudden fall in level of consciousness

Repeated or prolonged seizures Rising arterial carbon dioxide tension with respiratory acidosis

Case Study #545 year old male in the ICU admitted four days ago with necrotizing pancreatitis. He was intubated on admission. His current ventilator settings are IMV rate of 14, tidal volume 600 mL, PEEP 5 and FiO2 50%.

The nurse calls you because after the patient was turned and washed he desaturated to 70%.She has already turned the FiO2 up to 100% and his saturation has not responded.

Differential Diagnosis• Pneumonia• Lobar collapse• Pneumothorax• Pulmonary embolus• Aspiration• Sepsis• Pulmonary edema• Mucous plugging• Bronchospasm• ETT is dislodged

What do you do?• Take patient off the ventilator and hand bag

» Rule out ventilator problem» Assess degree of airway resistance

• Listen to the lungs» Rule out pneumothorax, fluid overload, bronchospasm

• Order a CXR, ABG» ABG will be bad, but will assess acidosis, and ventilation» CXR will assess ETT placement, lobar collapse, effusion,

pneumonia, etc.» Does patient require bronchoscopy?

• Pass a suction catheter» Rule out an occluded, dislodged ETT and assess secretions

• Give a bronchodilator» Can’t hurt! May loosen secretions

• If chest tubes in place, make sure on suction and assess for air leak• Adjust ventilator to compensate worsening respiratory failure



Pulse Oximetry

Sa02 > 90%

Sa02 < 90%



Step 1Assess Airway

Step 2


Intubated

Not intubated

ETT good position


Re-intubate

intubate


Assess Breathing


Check CXR, ABG

Tubethoracostomy



Labs & ABG normal

ETTdislodged





ASSESS PATIENT

http://www.aic.cuhk.edu.hk/web8/ards_pa_cath.JPG

ARDS• A patient must meet all of the following:

– Acute onset of respiratory symptoms– CXR with bilateral infiltrates– No evidence of left heart failure– PaO2/FiO2 < 200mm Hg (regardless of PEEP)

– American-European Consensus Conference on ARDS (Am J Resp Crit Care Med 149:818, 1994)

• The following are implied:– Previously normal lungs– Decreased lung compliance– Increased shunting– Hypoxemic respiratory failure

hypoxia, respiratory failure and altered mental status

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