COMPLICACIONS DE LA VENTILACIÓ MECÀNICA NO INVASIVA

www.idibapsrespiratoryresearch.org

Dr. Miquel FerrerUVIIR, Servei de Pneumologia, Hospital

Clínic, IDIBAPS, CibeRes, Barcelona. E-mail: miferrer@clinic.ub.es

Barcelona, 3 de novembre de 2010

Complicaciones y resolución de problemas

Complicaciones de la VNI

Predictores de fracaso:• IR hipercápnica

• IR hipoxémica

• Causas frecuentes de fracaso

Factores que contribuyen al fracaso de la VNI• Relacionados con el entorno y/o equipo asistencial

• Contraindicaciones de la VNI

• Relacionados con el paciente

• Técnicos

How to Reduce Air Leaks During NIV

Proper interface type and size

Proper securing system

Mask-support ring

Comfort flaps

Tube adapter

Hydrogel or foam seals

Chin strap

Lips seal or mouth taping

Nava S et al. Respiratory Care Jan 2009 vol 54 no1

How to Reduce the Risk of Skin Damage During NIV

Proper harness and tightening

Skin and mask hygiene

Nasal-forehead spacer• To reduce the pressure on the bridge of the nose

Forehead pads• To obtain the most comfortable position on the forehead

Cushioning system between mask prong and forehead

Remove patient’s dentures when making impression for molded mask

In home care, replace the mask according to the patient’s daily use

Skin pad

Nava S et al. Respiratory Care Jan 2009 vol 54 no1

Úlceras cutáneas

Riesgo de lesión cutánea

Una solución posible: la máscara facial total

Otra solución: “Helmet”

• No siempre aparecen donde se espera!!!

Úlcera por presión

Predictores de fracaso de la ventilación no invasiva

Insuficiencia respiratoria hipercápnica Insuficiencia respiratoria hipoxémica

Predictors of failure: NIV for hypercapnic respiratory failure

Advanced age

Higher acuity of illness (APACHE score)

Uncooperative

Poor neurological score

Unable to coordinate breathing with ventilator

Large air leaks

Edentulous

Tachypnoea (>35/min)

Acidaemia (pH <7.18)

Failure to improve pH, heart and respiratory rates or Glasgow Coma Score within the first 2 hours

Soo Hoo et al. Crit Care Med 1994; 22: 1253–61Ambrosino et al. Thorax 1995; 50: 755–7

Confalonieri et al. Eur Respir J 2005; 25: 348–55

Non-COPD conditions: Pneumonia (n=37) Neuromusculoskeletal disorders (n=11) Pulmonary edema (n=9) Bronchiectasis (n=5) Sepsis (n=3) Asthma (n=3)

Outcomes of NIV in non-COPD patients by specific diagnosis

Variables associated with in-hospital NIV failure (n=22/120)

Risk stratification of NPPV failure in 1,033 consecutive patients admitted to experienced hospital units

• Two intensive care units

• Six respiratory intermediate care units

• Five general wards

NPPV was successful in 797 patients

At admission

After 2 h of NIV

Predictors of failure: NIV for hypoxaemic respiratory failure

Diagnosis of ARDS or pneumonia SAPS ≥35 Lower PaO2/FIO2 (100 or below) Low pH Age >40 years Septic shock Multiorgan system failure Failure to improve PaO2/FIO2 >146 within first hour

Antonelli et al. Intensive Care Med 2001; 27: 1718–28.Rana et al. Crit Care 2006; 10: R79.

• Eight ICUs• n=354:

• Success: 246• Failure: 108

ICU mortality

%

0 20 40 60 80 100

Trauma

CPE

Extrapulmonary ARDS

Pulmonary ARDS

HAP

CAP

NIV-success

NIV-failure

n=7

n=10

n=7

n=0

n=0

n=18

n=9

n=1

n=4

n=0

n=33

n=8

Independent predictors of NIV failure: Age > 40 yrs PaO2/FiO2 <146 ARDS or CAP SAPS >35

Failure rate: 70%

• Patients with shock: 100%

Independent predictors of NIV failure (excluded patients with shock):

• Metabolic acidosis

• Severe hypoxemiap<0.01

Mortality in patientsfailing NIV

Actual Predicted

%

0

20

40

60

80

100

Causas frecuentes de fracaso de la ventilación no invasiva

Relacionados con el entorno o el equipo asistencial Relacionados con el paciente Factores técnicos

Common reasons for NIV failure

Environmental/caregiver team factors

• Lack of skilled, experienced caregiver team

• Poor patient selection

• Lack of adequate monitoring

Selection guidelines for NIV in the acute setting Appropriate diagnosis with potential reversibility (COPD,

congestive heart failure

Establish need for ventilatory assistance

• Moderate to severe respiratory distress

and

• Tachypnoea (>24 for COPD, >30 for CHF)

• Accessory muscle use or abdominal paradox

• Blood gas derangement: pH <7.35, PaCO2 >45, or PaO2/FiO2 <300

Contraindications of NIV Respiratory or cardiac arrest

Too unstable:• Shock

• Myocardial infarction requiring intervention

• Uncontrolled ischaemia or arrhythmias

• Uncontrolled upper GI bleed

• Unevacuated pneumothorax

Unable to protect airway*• Excessive secretions

• Poor cough

• Impaired swallowing

*Relative contraindications

Aspiration risk*

• Distended bowel; obstruction or ileus

• Frequent vomiting

Uncooperative or agitated*

Unable to fit mask

Recent upper airway or oesophageal surgery

Multiorgan system failure (more than 2)

Common reasons for NIV failure

Patient-related factors

• Intolerance

• Mask problems:

• Discomfort

• Poor fit

• Skin ulceration

• Claustrophobia

• Agitation

• Excessive secretions, inability to protect airway

• Progression of underlying disease

Approach to the agitated/intolerant patient using NIV

Common reasons for NIV failure

Technical factors

• Inadequate equipment

• Failure to ventilate

• Failure to oxygenate

• Patient–ventilator asynchrony

• Air leaks

How do ventilators perform in the presence

of leaks?

Portable or “NIV” ventilators ICU ventilators

• With NIV modes• Without NIV modes

Varying conditions had a generally small effect on triggering times, suggesting that :

• There is a largely unavoidable element to the triggering delays intrinsic to the design of the ventilators

• Effective compensation of leaks

Eight ICU ventilators featuring an NIV mode. Tests conducted in:

• Absence of leaks

• Presence of leaks with and without activation of the NIV mode

Trigger delay

Workload of triggeringInspiratory trigger

pressure drop

In most ventilators, leaks:

• Increased trigger delay and workload

• Decreased pressurization and delayed cycling

NIV mode partly corrected these problems:

• Large variations between machines

• In some ventilators the NIV mode worsened the leak-induced dysfunction

Leaks interfere with several key functions of ICU ventilators

• NIV modes can correct part or all of this interference

• Wide variations between machines in terms of efficiency

August 2010

NIV algorithms can reduce asynchronies due to leaks:• This confirms bench test results, but …• Some of these algorithms can generate premature cycling

65 patients included 5 different ICU ventilators, with and without NIV algorithm

Bilevel or ICU ventilators in the presence of leaks?

Comparison of nine ICU ventilators with NPPV function with a bilevel ventilator in the presence of leaks

At baseline all ventilators:

• Delivered adequate tidal volumes

• Maintained airway pressure

• Synchronized with the simulator (no missed efforts or auto-triggering)

As the leak was increased, all ventilators except the Vision and Servo I:

• Needed adjustment of sensitivity or cycling criteria to maintain adequate ventilation

• Some transitioned to backup ventilation

Significant differences in triggering and cycling were observed between the Servo I and the Vision ventilators.

The Vision appears the optimal ventilator for NIV conditions:• No need for adjustment of sensitivity or cycling criteria • Optimal triggering performance

Fracaso de la ventilación

Válvula espiratoria

Evita la re-inhalación de CO2

Nunca olvidar la válvula!!!

Successful NIV: Important factors

More likely with a good team • A skilled, experienced staff helps to optimize outcomes

The underlying disease is an important determinant• Selecting appropriate patients and monitoring them closely

Severity at presentation

Change in physiology after a short period of NIV• In failure to ventilate or oxygenate, rapidly assess for

reversible contributing factors

• Be prepared to intubate without undue delay if rapid reversal cannot be achieved

A systematic approach to troubleshooting can help assure the best possible NIV outcomes