Monaldi Arch Chest Dis2003; 59: 4, 342-344 PROCEEDINGS OF “ADVANCES IN PULMONARY REHABILITATION”

Therapist driven protocolsM. Vitacca

About 80% of patients admitted to an ICU andmechanically ventilated because of acute respira-tory failure, resume spontaneous breathing quiteeasily after few days of ventilation [1]. The wean-ing success rate differs between the studies de-pending on the case mix and referrals of any indi-vidual Intensive Care Unit (ICU). In particularBrochard et al. stated that “the length of weaningis first explained by the etiology of the diseases,patients with Chronic Obstructive Pulmonary Dis-ease (COPD) being the most difficult to separatefrom the ventilator” [2]. The 20% rate of unsuc-cess is mainly concentrated in specific popula-tions, where age, residual or premorbid compro-mise of the cardiorespiratory or neuromuscularsystems render the discontinuation from mechani-cal ventilation particularly difficult [1]. It was re-ported that 41% of the total time of mechanicalventilation was devoted to weaning, with large dif-ferences between patients with different diseases[1]. Endotracheal intubation per se, long-term se-quelae after intubation, heavy sedation of curariza-tion, myopathy, sepsis and multiple organ failure(MOF), the use of continuous intravenous seda-tion, diaphragmatic atrophy, malnutrition, infec-tive complications, chronic airway obstruction,feeding aspiration, bone demineralization, proteinwastage and a decrease in total body water are of-ten associated with prolonged mechanical ventila-tion [1]. Several studies have been performed in anattempt to assess the best ventilatory methods todiscontinue ventilatory support at the earliest pos-sible time. They were recently reviewed in an arti-cle by Butler [3] and coworkers, that conluded thatsince there are very few rigorous randomized trials[2, 4], more work is required in this area, and inparticular that “ from the studies reviewed theycould not identify a superior weaning techniqueamong the three most popular modes, T-piece,Pressure Support Ventilation (PSV), or synchro-nized intermittent mandatory ventilation (SIMV)”.

Our recent data [5, 6] show that spontaneousbreathing trials and decreasing levels of inspiratorypressure support are equally effective in weaningCOPD tracheostomized patients undergoing mechan-ical ventilation for more than 15 days. Whatever theexplanation, it is important for us to stress the pointthat in the weaning process, the method employed isprobably less important than the confidence and fa-miliarity with the technique adopted, and that the

Respiratory Intensive Care Units, “Salvatore Maugeri” Foundation IRCCS, Scientific Institute of Gussago, Italy.

Corrispondence: Michele Vitacca MD “Salvatore Maugeri” Foundation IRCCS, Scientific Institute of Gussago, Via Pindolo 23,25064 Gussago (BS) Italy; e-mail mvitacca@fsm.it

Monaldi Arch Chest Dis 2003; 59: 4, 342-344.

Table 1. - Recommendations for MV weaning proto-cols (modified from Ref 1)

➢ Driven protocols should be included during tentativeweaning.

➢ ICU clinicians should utilize protocols for liberatingpatients from MV in order to reduce its duration.

➢ Clinicians should conduct a SBT at least once daily toidentify those patients ready for liberation from MV.

➢ If the patient fails: remediable factors? change modal-ity of ventilation; repeat every day SBT; in the case ofrepeated failures a tracheostomy should be considered.

➢ If SBT is OK consider extubation.

➢ Use of protocols with a) daily tentative ventilatorycessation and b) drastic reduction of sedation.

➢ Evidence based approach protocol; team approach; in-teractive education; opinion leaders; reminders.

same ventilatory mode may produce different out-comes depending on the underlying pathologies [1,3]. Indeed recent papers have stressed the concept ofusing standardized protocol to wean the patient awayfrom mechanical ventilation [7, 8, 9].

Therapist driven protocols (TDP) are a con-sensus of medical knowledge and opinion that issummarized into a care plan or algorhytm withchanges in therapy directed by changes in objec-tive measurable patient variables [1]. The TDPteam usually consists of the physician, the patient,the family, the nurse and a respiratory therapist(RT) [1]. The daily plan of a TDP consists ofrecording functional activities early in the morn-ing, followed by a rest period before initiating theweaning process in the optimal position for in-stance sitting upright in bed or sitting upright in achair [1]. The plan for a TDP also adressess pre-vention and amelioration of the deleterious effectsof bed rest, communication, emotional support,psychological well-being and function [1]. Initialevaluation will include assessment of the patientand ventilator status and patient-ventilator syn-chrony. This evaluation is usually performed rou-tinely every 2/4 hours and with each ventilator set-ting change. Table 1 shows recommendations forthe use of Mechanical Ventilation (MV) weaningprotocols, while table 2 shows the tips for im-plemetations of these TDP during weaning. Table

343

THERAPIST DRIVEN PROTOCOLS

3 propose an example of a weaning protocol usedin our unit [6]. Saura [9] studied 51 patientsweaned by a fixed protocol who were studied

prospectively and compared with 50 retrospectivecontrols. When the patients were clinically stablereaching the following criteria: PaO2 > 60 mmHgwith FiO2 less than 0.4, Pimax > 20 cmH2O, RR <35 act/min and VT > 5 ml/kg they underwent aweaning trial of a 2 hour period of spontaneousbreathing. The implementation of this weaningprotocol decreased the duration of MV and ICUstay by increasing the number of safe direct extu-bations. Similar results were found by Ely [7] whodemonstrated that the daily screening of the respi-ratory function of ventilated patients, performedby nurses or respiratory therapists, followed by tri-als of spontaneous breathing and notification totheir physicians when the trials were successful,can reduce the duration of ventilation, the cost ofintensive care and was also associated with fewercomplications. Similar results were also obtainedlater on by Koleff et al. [8], stressing the opinionthat objective “scientific” methods improve out-comes in mechanically ventilated patients. Bymeans of historical comparison our experience [5,6] also shows that the application of a well-definedprotocol (see table 3), independent of the modeused, is associated to a greater weaning successrate, shorter time under mechanical ventilation and

Table 2. - Tips for implementations of TDP duringweaning (modified from Ref 1)

➢ Identify the patient care issue

➢ Test your institution’s lengths of stay and complica-tions rates

➢ Design protocols (evidence based methods, local ex-perts, review of protocols)

➢ Change of “weaning culture”

➢ Create a team approach (hospital administrator, physi-cians, nurses, respiratory therapist, ethicists)

➢ Define local main goals, succesful and unsuccesful

➢ Avoid changes in personel (dedicated personel)

➢ Education, timely feedback, compliance monitoring,appropriate outcomes, be pragmatic, improve yourprotocol during time

➢ Avoid rigid interpretation of the rules

➢ Clinical judgement remains important

➢ Periodic refresher implementation processes

Table 3. - Example of weaning protocol used in the weaning centre of Fondazione S. Maugeri of Gussago(modified from Ref 6)

Patient presents:Minute Ventilation ≤ 15 L/min;FiO2 ≤ 60%; PEEP ≤ 10 cmH2O;alertness daily re-evaluation

You can start weaning

Patient presents the following parameters:Minute Ventilation < 15 L/min; FiO2 ≤ 40 %; PEEP ≤ 6 cmH2O; HR < 140 b/min; PaO2/FiO2 ≥ 200; f/VT ≤ 105; MIP ≥ 20cmH2O; RR < 25/min; pH > 7.35; systolic pressure > 100 and <150 mm Hg; SatO2 > 90 %; presence of cough, goodneurological status, no agitation; no sedatives; no vasopressors; no arithmias

Start spontaneous breathing trial (SBT)

Does the patient present signs of distress?f > 35 a/min; SatO2 < 90% with FiO2 ≥ 40%;HR> 145 b/min or increase in HR > 20%; arhitmiassystolic pressure > 180 or < 70 mm Hg; agitation

start the weaning process:

A) Decrease level of PSV (2 cmH2O/ twice a day)– In case of distress back to previous steps

B) SBT: increase lenght of SBT (30 minutes; 1, 2, 4, 8 hours)– In case of distress go back to previous steps

➧➧

➧➧

➧➧

➧➧➧➧

➧➧➧➧

➧➧

extubation

yes no

no

no

yes

yes

FiO2 = Fraction of inspired O2; PEEP = Positive end expiratory pressure; HR = heart rate; f/VT = Frequency on tidal volume ratio; MIP =maximal inspiratory pressure; RR = Respiration rate; PSV = pressure support ventilation.

344

M. VITACCA

4. help to safely and efficiently liberate patientsfrom MV reducing unnecessary or harmful varia-tions approach.

References

1. ACCP, AARC, ACCCM task force. Evidence basedguidelines for weaning and discontinuing ventilatorysupport. Chest 2001; 120: 375s-395s

2. Brochard L, Rauss A, Benito S, Conti G, Mancebo J,Rekik, Gasparetto A, Lemaire F. Comparison of threemethods of gradual withdrawal from ventilatory sup-port during weaning from mechanical ventilation. Am JRespir Crit Care Med 1994; 150: 896-903.

3. Butler R, Keenan SP, Inman KJ, Sibbald WJ, Block G.Is there a preferred technique for weaning the difficult-to-wean patient? A systematic review of the literature.Crit Care Med 1999; 27: 2331-2336.

4. Esteban A, Frutos F, Tobin M, Alia I, Solsona J,Valverdu I, Fernandez R, De La Cal MA, Benito S,Tomas R, Carriedo D, Macias S, Blanco J. A compari-son of four methods of weaning from mechanical ven-tilation. N Engl J Med 1995; 332: 345-350.

5. Vitacca M, Vianello A, Colombo D, Clini E, Porta R,Bianchi L, Arcaro G, Guffanti E, Lo Coco A, Ambrosi-no N. Comparison of two methods for weaning COPDpatients requiring mechanical ventilation for more than15 days. Am J Respir Crit Care Med 2001; 164: 225-230.

6. Vitacca M, Giarelli A, Paneroni M, Barbano L, Am-brosino N. I protocolli guidati dal terapista respiratoriodurante le fasi di svezzamento dalla ventilazione mec-canica. Rass Pat App Resp 2002; 17: 198-208.

7. Ely EW, Baker AM, Dunagan DP, Burke HR, SmithAC, Kelly PT, Johnson MM, Browder RW, BowtonDL, Haponik EF. Effect of the duration of mechanicalventilation of identifying patients capable of breath-ing spontaneously. N Engl J Med 1996; 335: 1864-1869.

8. Kollef MH, Shapiro SD, Silver P, St John RE, PrinticeD, Sauer S, Ahrens TS, Shannon W, Baker-ClinkscaleD. A randomized controlled trial of protocol-directedversus physician directed weaning from mechanicalventilation. Crit Care Med 1997; 25: 567-574.

9. Saura P, Blanch L, Mestre L, Vallés J, Artigas A, Fer-nandez R. Clinical consequences of the implementationof a weaning protocol. Intensive Care Med 1996; 22:1052-1056.

shorter LWU and hospital stay than uncontrolledclinical practice. Table 4 summarizes criteria usedin literature for TDP both to start weaning tenta-tive or to test weaning steps failure.

In conclusion therapist driven protocolsshould: 1. be used routinarly during weaning 2. notrepresent rigid rules but rather guides to patientcare. 3. moreover evolve and improve over time asclinical and institutional experience increase.

Table 4. - Criteria used in literature to start weaningor to test weaning steps failure (modified from Ref 1)

Objective measurements:– PaO2 > 60-65 mmHg; SaT O2 >88%- 90%, FIO2 40%-

60%, PaO2/FiO2 >/= 200; PEEP < 5-10 cmH2O– Haemodinamic stability: no vasopressors or inotrops,

dopamyn < 5mcg/Kg/min, no arhitmie; sistolic pressure> 90 mmHg e < 180 mmHg; HR > 50 e < 140

– Temperature: < 37-38°C– No respiratory acidosis under MV; ph > 7.35, PaCO2 < 50

mmHg– Haemoglobin > 8/10 g/dL– Good neurological level; no sedative; GCS >/= to 10-13– Effective cough– Normal serum electrolytes– No use of accessory muscles; MIP >/= 20-22 cmH2O

Subjective measurements:Clinical evaluation of:

respiratory load;possibility of withdraw from MV;no distress signs;possibility of cough

Parameters on ventilator:– FR </= 35 acts/min;– Minute ventilation </ = 10-15 L/min;– F/Vt =/< 105;– Vital Capacity: >10 mL/Kg or double of VTe;– VTe > 5 mL/Kg or > 0.3 L

PEEP = Positive end expiratory pressure; F/Vt = Frequency on tidal volume ratio; GCS = Glasgow coma scale; MIP = maximalinspiratory pressure; VTe = Tidal Volume; HR = Heart Rate.