Page 96 - JSOM Summer 2022

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BiPAP is a form of pressure support (PS) ventilation delivering intubation. The use of NIV and dissociative doses of ketamine,
“bi-level” pressure on both inspiration and expiration. BiPAP a treatment modality referred to as DSI (delayed sequence in-
is a time or flow-cycled change of the CPAP level. 11,12 This tubation), is a clinical algorithm used in the critically ill respi-
mode delivers both a set inspiratory pressure (IPAP) and expi- ratory patient in an effort to achieve effective preoxygenation
ratory pressure (EPAP), with the set IPAP delivering the higher prior to intubation or to allow the patient to achieve a level
pressure and cycling to the lower EPAP to improve patient of sedation and comfort to effectively oxygenate without intu-
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comfort while also maintaining open alveoli. This can also be bation. DSI is functionally procedural sedation with the pre-
conceptualized by defining it as CPAP with PS, in which PS is dicted outcome being an increase in preintubation oxygenation.
added to the baseline PEEP every time the patient initiates a In an observational study performed with a total of 62 patients,
breath. In initial management of the acutely hypoxemic pa- with 39 receiving DSI with CPAP and 23 receiving preintuba-
tient, the gradient between IPAP and EPAP should be kept the tion oxygenation via nonrebreather, those patients receiving DSI
same (i.e., increasing the EPAP by 3cmH O should be matched had an increase in SpO > 93% and successful intubation. 15
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by an increase of IPAP by 3cmH O ) with the target of im-
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proving oxygenation. 11,12 In the acutely hypercapnic patient, Patients receiving dissociative doses of ketamine should receive
the end goal would be to improve Vt and minute ventilation 1–1.5mg/kg and CPAP or BIPAP with a PEEP of 5–15 cmH O
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to decrease PaCO , achieved by widening the gradient between and a PS of 5–10 cmH O, with both settings titrated to oxy-
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IPAP and EPAP. 11–13 genation, respiratory effort, and compliance. Sedation-dose
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ketamine is generally a safe practice as long as patients are
Both modes are to be used on conscious patients with the continuously monitored by advanced airway practitioners. 15
ability to maintain their own airway and the ability to spon-
taneously breathe. Patients with impending airway collapse FIGURE 1 Elaboration of the DSI procedure used in this prospective
or potential to become apneic should be treated with inva- observational study. 15
sive airway intervention in an effort to protect the airway and
breathing process. Additionally, in all patients that are being Patient
treated with NPPV, airway pressures must be closely moni- Requires emergent airway
management, but resists
tored. Patients with PEEP or IPAP exceeding 20 cmH O are pre-intubation preparation due
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at increased risk for mask leaks, gastric inflation, increased to altered mental status
anxiety, and barotrauma. Increases in gastric inflation put the
already unstable airway at risk for aspiration due to vomiting.
While using devices without electronic monitoring of airway
pressure, the provider should pay close attention to patient Dissociation
comfort, airway resistance/compliance, and breath sounds Administer slow IV push of
with frequent reassessment. dissociative dose of Ketamine;
administer additional doses until
patient dissociation achieved.
When to Use NPPV
10–15 seconds
The primary indication for the use of any form of NIV/NPPV
is acute respiratory failure (ARF). 1,2,4–6,12 The use of NIV/ Preoxygenate
NPPV is commonly used in the following acute and chronic • Use NRB mask plus NC.
conditions: chronic obstructive pulmonary disease (COPD), • If SpO <95%, switch NRB
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for non-invasive CPAP.
asthma, hypercapnic respiratory failure, hypoxemic respira- • Denitrogenate for 3 minutes.
tory failure, ARDS, pneumonia, nocturnal hypoventilation,
and amyotrophic lateral sclerosis (ALS). 1,2,4–6,13 NIV should 3 minutes
also be considered postextubation as an effective weaning
tool in a subset of patients with acute-on-chronic respiratory Paralyze
4–6
failure from COPD. Applying immediate NIV to patients Administer Succinylcholine
at high risk for extubation failure improves outcome by de- or Rocuronium
creasing the need for reintubation. 4–6,11–13 NIV/NPPV should be
considered as the first line treatment in any ARF patient when
presenting with two or more of these signs and symptoms: ApOx
accessory muscle use, paradoxical breathing, respiratory rate Perform apneic
greater than 25 breaths per min, severe dyspnea or increased oxygenation with NC
dyspnea in COPD, PaCO above 45 mmHg, and a P/F (PaO /
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FiO ) ratio less than 200. 1,2,4–6,14 P/F ratio is used as a predictor 45–60 seconds
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for ARDS with the following criteria: 200–300 mild ARDS
Intubate
(27% mortality); 100–200 moderate ARDS (32% mortality); Perform endotracheal
<100 severe ARDS (45% mortality). 1,2,4–6,14 P/F ratio should intubation
only be used as a rule of thumb when the PaCO is normal
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and V/Q (ventilation/perfusion) shunt is not suspected. 1–2,4–6,14
Patients That Will Benefit From NPPV
Pharmacological Adjuncts in NPPV
Patients in acute exacerbation of chronic obstructive pulmo-
As an additional adjunctive intervention, NPPV may be used nary disease (AECOPD) with hypercapnia or a respiratory ac-
in conjunction with medication to delay or forego the need for idosis (PaCO > 45 mmHg or pH < 7.35) are likely to benefit
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94 | JSOM Volume 22, Edition 2 / Summer 2022