Extubations Protocols in the Neurocritical Patient

Abstract

Within neurosurgical procedures, it has been observed that the failure rate covers up to 70%. It has been observed that early extubation has been associated with a decrease in mortality as well as a shorter hospital stay. Delaying extubation to obtain sustained neurological improvement during the recovery phase does not guarantee successful extubation. Studies have observed that up to 80% of patients with Glasgow less than 8 have been successfully extubated. It must be remembered that the Glasgow scale does not assess the difference in disorders of consciousness nor does it evaluate stem reflexes in intubated patients, so current studies have opted for other scales that allow us to assess the state of consciousness with more criteria to evaluate. It is demonstrated that the delay in extubation for neurological recovery did not show successful extubation and was associated with an increase in nosocomial pneumonia, longer stay in the ICU, and hospital cost. It is important to emphasize the evaluation of this type of patients, placing special emphasis on the cardiac and pulmonary repercussions of patients who suffer neurological lesions, since alterations that could go unnoticed could mean a failure to extubation with repercussions on the morbidity and mortality of patients.

1. Introduction

In neurosurgical procedures, it has been observed that the rate of extubation failure covers up to 70%. It is important to seek early extubation, since it has currently been associated with a decrease in mortality and a shorter hospital stay.

Within the extubation criteria we have that adequate hemodynamic and ventilatory status are important for the patient. The approach to ventilatory aspects emphasizes adequate oxygenation and lung function, while in hemodynamic aspects, patients must always have an adequate balance of this, without the support of any vasopressor.

One of the main objectives of this chapter is the approach to the neurocritical patient. For some time it has been observed that the majority of patients admitted for neurosurgical procedures are maintained under orotracheal intubation by mechanical ventilation regardless of the neurological etiology, the surgical procedure and the anesthetic management.

Today, the use of neuromonitoring is essential in all patients undergoing neurological surgery, and this guides us on the maintenance of intracranial pressure, cerebral perfusion and cerebral oxygen consumption, in order to carry out adequate extubation in neurocritical patients.

At the same time, an adequate pre-anesthetic evaluation is of vital importance to know the patient undergoing surgery, where the type of procedure is evaluated, the approach and to know if there is any cardiac or pulmonary repercussion that could lead to a failed extubation and thus be able to maintain our neurosurgical patient extubation protocol in the best conditions.

2. Epidemiology

The main causes leading to advanced airway management in neurological patients are cerebrovascular event (CVD), whether of ischemic or hemorrhagic origin, head trauma (TBI), subarachnoid hemorrhage, and parenchymal hemorrhage. It has been proven that prolonged mechanical ventilation after orotracheal intubation is associated with pneumonia, venous thrombosis, increased hospital stay, and worse clinical prognosis [1]. Friedman [2] carried out a study where he analyzed the complications of patients with subarachnoid hemorrhage secondary to an aneurysm and concluded that patients with pulmonary complications had a worse prognosis than those who did not have this alteration. He, in turn, also found that patients with prolonged intubation had more complications at the pulmonary level [2]. TCE has remained a serious health problem worldwide. Annually it is estimated that there are 10 million TCEs that lead to death or hospitalization. In the United States, the average ranges from 1.4 million per year, reaching a mortality of up to 50,000 patients [3].

Currently, neurosurgical teams and neuroanesthesiologists have focused on the search for safe extubation protocols for neurocritical patients and avoid the previously mentioned complications in these patients.

3. Content

Within the area of neurocritical patients we have different terms that should be mentioned.

• Delayed extubation is defined as those patients who have not been extubated in the first 48 hours; a rate of 30% is currently estimated in neurocritical patients.

• Failed extubation is seen when there is a need to reintubate and resume treatment with ventilatory support between 24 and 72 hours after the removal of the tracheal tube.

• Early extubation is mentioned as the transition from mechanical ventilation of a patient to spontaneous ventilation within the first 6–8 hours after surgery.

• The term Ultra fast track is when the patient is extubated in the operating room, terms that have been described in cardiology surgery [4].

It is worth mentioning that the term Ultra fast track is mainly attributed to early extubation in patients undergoing cardiac surgery, and has gained importance since the 1950s, since due to the lack of adequate equipment and personnel in care units Intensive care, the lack of mechanical ventilation providers, and the long stays of patients with unfavorable prognoses, patients were subjected to early extubation to avoid complications resulting from poor postoperative management. However, these presented serious complications such as severe hypoxemia, acidosis, which led to death, derived from poor management in extubation, so that in the mid-70s, patients in the postoperative period remained under Mechanic Ventilation with better criteria. and handling that paradoxically favored its prognosis. The rapid evolution of cardiovascular sciences led to an increase in the number of patient care, so new programs were implemented that benefited the study of the Fast Track extubation technique, to reduce hospital stays and today it is one of the techniques of extubation with a greater number of study protocols and validation in the postoperative management of patients with heart disease [5].

However, in the area of neuroanesthesia, there is a huge lack of studies and protocols that benefit or indicate the safest tools to take, when faced with whether or not to extubate a patient.

At the moment of having any alteration at the level of the central nervous system, the awake state is reduced and induces patients to present hypoventilation, which can lead to bronchial aspiration. One of the first measures has been to support the airway with orotracheal intubation. Goals for adequate cerebral blood flow should be maintained in all neurological patients. These include treatment of hypoxemia with PaO₂ targets greater than 60 mmHg, control of PaCO₂ of 32–45 mmHg, as well as adequate cerebral perfusion pressure between 50 and 150 mmHg. Due to the great complications that are obtained in patients with extubation failure, the fear of extubation has been the subject of controversy regarding when to withdraw ventilatory support.

The Glasgow coma scale in the neurocritical patient has been used as a criterion for extubation; currently, delaying extubation to obtain neurological improvement during the recovery phase does not guarantee successful extubation. Studies have observed that up to 80% of patients with Glasgow less than 8 have been successfully extubated. It must be remembered that this scale does not assess stalk reflexes in intubated patients. At present, other scales have been evaluated that allow us to assess the awake state in the neurosurgical patient with more precision.

Karim Asehnoune evaluated the predictors of extubation in patients with brain damage in a multicenter study. A total of 437 patients were included using the VISAGE score (visual pursuit, swallowing, age, Glasgow for extubation) (Table 1).

Extubation success score	Assigned points according to items
Age < 40 yr old (yes/no)	1/0
Visual pursuit (yes/no)	1/0
Swallowing attempts (yes/no)	1/0
Glasgow coma score > 10 (yes/no)	1/0
VISAGE = visual pursuit, swallowing, age, Glasgow for extubation

Table 1.

VISAGE score.

This is an author’s work Asehnoune et al. [6].

This score was used to assess the success rate in extubation where those patients with a score of 0 had a 23% extubation rate, a score of 1 with 56% extubation, and it was significantly higher in patients with a score of 2–3 (70–90% extubation). Score equal to or greater than 3 predict extubation success with a sensitivity of 62% and a specificity of 79% (Figure 1).

Figure 1.

Rate of extubation success according to the number of predictive factors. This is an author’s work Asehnoune et al. [6].

In this study, the main cause of brain damage was traumatic brain injury and this, in turn, had the highest rate of extubation. The main causes of extubation failure were neurological disorders, hypoxemia, mismanagement of endotracheal secretions, cardiovascular failure, and postextubation stridor [5].

In 2021, the PRICE (Predicting Intratentorial Craniotomy Extubation) survey was conducted with 5453 physicians responsible for neurosurgical management. These surveys were addressed to Neuroanesthesiologists, Neurointensivists and Neurosurgeons whose primary objective was to estimate extubation times in neurosurgical patients and assess their prognosis. It was found that the proportion of patients with extubation at the end of the surgical procedure was higher in high-volume centers compared to low-volume centers and that the anesthesiology service was the service that had the highest extubation of neurosurgical patients together with support. of neurosurgeons. The main factors associated with not performing an early extubation were based on the course of the surgical procedure, the patient’s awake state and if he presented any alteration at the bulbar level (Figure 2).

Figure 2.

Predictors selected by respondents to identify candidates for early extubation after elective infratentorial craniotomy. Airway indicates suspicion or history of difficult airway management; baseline, patient’s physical status before surgery; brainstem, evidence of bulbar dysfunction; course, course of surgery; duration, duration of surgery; end time, the time of day when surgery ends; imaging, preoperative imaging; LOC, level of consciousness. This is an author’s work Gaudet et al. [7].

It was concluded that the decision for early extubation should be made maintaining adequate communication between neurosurgeons, neuroanesthesiologists and neurointensivists, as well as adequate clinical knowledge of the patient prior to the surgical event [4].

Within the extubation criteria are goals based on hemodynamic, ventilatory and neurological patterns.

One of the neurological parameters that has been used is the Glasgow coma scale, Coplin et al., demonstrated that the delay in extubation for neurological recovery did not show successful extubation and was associated with an increase in nosocomial pneumonia, longer stay in the ICU and hospital cost [7]. We know that the Glasgow coma scale assesses the motor, speech and visual area, but one of its main limitations is that it cannot be assessed in a patient under ventilatory support, since it does not differentiate between the patient’s waking state disorders, does not it assesses stem reflexes and is primarily not useful in the patient under orotracheal intubation [8].

A possible alternative is to use the Coma Recovery Scale-Revised, which offers us a more extensive evaluation, assessing auditory function, visual function, motor function, oromotor or verbal function, communication capacity, and ability to wake up. Chatelle et al. describe the scale as being more comprehensive and capable of better detecting a patient’s awake state (Figure 3) [9].

Figure 3.

Parameters evaluated by the Coma Recovery Scale-Revised that make it possible to identify the state of consciousness of a patient. This is an author’s work Chatelle et al. [9].

Bodien et al., carried out a statistical analysis about the sensitivity and specificity of the Coma Recovery Scale-Revised to adequately detect and identify the state of consciousness of the patient and through a ROC (Receiver Operating Characteristic) analysis, they found an area under the curve of 0.98, which far exceeds the 0.681 of the Glasgow Coma Scale, which was reported by Namen et al. [9, 10] (Figure 4).

Figure 4.

ROC analysis to identify the sensitivity of the Coma Recovery Scale-Revised to adequately identify the states of consciousness of patients. This is an author’s work Bodien et al. [10].

In order to establish an adequate extubation protocol in neurosurgical patients, spontaneous breathing test maneuvers must be taken into account, such as the T-piece test, continuous positive airway pressure (CPAP) with levels equal to those of pressure positive end-expiratory and invasive ventilation with low level pressure support (5–8 cmH₂O) or automatic tube compensation [11].

Navalesi and Frigerio analyzed the reintubation rate in neurological patients in the intensive care unit based on the following criteria: Glasgow coma scale greater than 8, presence of audible cough during suction, normal serum Na, core temperature less than 38.5°C, pH greater than 7.35, PaCO₂ less than 50 mm Hg or PAO₂/FiO₂ greater than 200 with positive end-expiratory pressure less than 5 cm H₂O, FiO₂ less than 0.4, heart rate less than 125 beats per minute, and systolic blood pressure greater at 90 mmHg without norepinephrine or epinephrine support. These patients were compared against a control group managed by different physicians with personal criteria for weaning from mechanical ventilation.

Both groups were analyzed and it was observed that the reintubation rate was 12% in the control group while 5% was manifested in the intervention group with the aforementioned criteria, concluding that those patients with neurological disorders who are taken with adequate both clinical and physiological objectives can improve outcomes and decrease the rate of reintubation in intensive care patients [12].

Bösel [14] published an algorithm about which patients are safe to perform extubation (in patients with neurological pathology in intensive care), if we analyze the criteria made by Navalesi and Frigerio we can see that the hemodynamic, ventilatory and neurological variables are very similar, with the exception that Bosel considers that time is a fundamental variable for performing an early tracheostomy and thus avoiding the risk of reintubation (Figure 5) [13].

Figure 5.

Suggestion for approaching extubation in the neuroscience intensive care unit. This is an author’s work Bösel [14].

Another piece of information included in the M. Jibaja algorithm is the Airway care score, which is useful for predicting the ability to maintain a safe airway (Table 2).

Grade	Cough during the aspiration maneuver	Number of secretions (need for passes)	Color of secretions	Viscosity of secretions	Interval of aspiration of secretions	Vomiting reflex
0	Vigorous	0	Clear	Aqueous	More than 3 h	Vigorous
1	Moderate	1	Clear brown	Frothy	Every 2–3 h	Moderate
2	Weak	2	Yellow	Dense	Every 1–2 h	Weak
3	Absent	≥3	Green	Sticky	<1 h	Absent

Table 2.

Airway care score.

This is an author’s work Jibaja et al. [15].

With this score, once the patients met the prerequisites to be able to be extubated, they analyzed the values and if they were above 7, the algorithm tells us to look for some etiology as a trigger for the ventilatory cause. If it was less than 7, the already established extubation criteria were used (Figure 6) [14].

Figure 6.

Algorithm for weaning from MV and extubation in neurocritical patients. This is an author’s work Jibaja et al. [15].

Another aspect that must be taken into account is the type of neurosurgical procedure to be performed. We know that infratentorial injuries, as discussed in the PRICE survey, are a challenge for neurosurgeons, neuroanesthesiologists, and neurointensivists, and this is due to the fact that infratentorial injuries have a higher rate of failed extubation, prolonged mechanical ventilation, pneumonia, high mortality, and increased hospital costs. Cai, assessed that lesions greater than 30 mm, which are associated with low torque dysfunction, patients with a history of previous craniotomy and sudden changes in blood pressure, were the main predictors of extubation failure in neurosurgical patients [6, 15, 16].

At the National Institute of Neurology and Neurosurgery of Mexico, criteria for extubation in patients undergoing posterior fossa surgery were analyzed and described in Table 3 [4].

Extubation criteria in posterior fossa surgery
Ventilation-oxygenation	Hemodynamics	Neurological
Respiratory rate 10–30 breaths per minute	Cardiovascular stability	GCS > 8 points
Regular respiratory pattern	Lack of dependency of vasoactive agents	Adequate psychological conditions
Max inspiratory pressure < 20 cmH2O	Temperature 35–37°C	Lack of depression of the respiratory center due anesthetics
Tidal volume > 6 ml/kg	Heart rate < 100 bpm	Integrity of the protective airway reflexes
FIO2 < 50%	MAP > 65 mmHg	Nausea reflex (IX, X)
Intrapulmonar shunt (Qs/Qt < 20%)	PH 7.35–7.45	Faringeal reflex (cough) (V, X)
PaO2 > 70 mmHg	HB >8 g/dL	Vocal folds mobility (X)
PaCO2 30–45 mmHg	Urine output >1 ml/kg/h	Integrity of the greater hypoglossal nerve (tongue movements, strength by palpation)
PaO2/FIO2 > 200	ICP < 15 mmHg	Reversal of the neuromuscular block

Table 3.

Extubation criteria in posterior fossa surgery.

This is an author’s work De La Serna-Soto et al. [4].

4. Conclusions

It must be taken into account that there are complications associated with the delay and failure of extubation in neurocritical patients, which is why all patients must be evaluated in detail prior to surgical intervention. The neurological examination is essential to know the state prior to the surgical procedure. We know that there are different extubation protocols for neurocritical patients and all of them should be reviewed in detail for a better prognosis. In turn, infratentorial lesions have a higher risk of extubation failure and that is why we must analyze and detail an adequate clinical history in our patient. Since there is not enough evidence for the extubation of these patients, the global implementation of extubation guidelines for neurocritical patients is recommended.