Home About Us Contact Us

 

Table of Content - Volume 6 Issue 2 - May 2017


 

Indications for invasive and non-invasive mechanical ventilator in patients of respiratory failure

 

Gajanan Vaijnath Halkanche1, Fazlullah Hashmi2*

 

1Associate Professor, Department of Medicine, Government Medical College, Latur, Maharashtra, INDIA.

2Assistant Professor, Department of Chest and TB, DR Shankarrao Chavan Government Medical College, Nanded, Maharashtra, INDIA.

Email: gajananhalkanche@rediffmail.com

 

Abstract              Background: Patients who developed respiratory failure had to be put on invasive mechanical ventilation in spite of known impending severe complications. Recently, physicians are using non-invasive ventilation for patients with respiratory failure of varied etiology. Aim: To study the indications for invasive and non-invasive mechanical ventilator in patients of respiratory failure. Material and Methods: A total of 216 critically ill Patients admitted in intensive respiratory care unit (IRCU) who developed respiratory failure due to various conditions and diseases were studied for the indications of invasive and non invasive ventilations. Results: Amongst 216 patients, 182 (84.2%) required invasive and 34 (15.7%) required noninvasive ventilator. Out of 182 with invasive ventilator, 138 (75.8%) were of acute respiratory failure (poisoning, ARDS, snake bite). Common indications of noninvasive ventilator was COPD (81%) followed by bronchial asthma (80%). Conclusion: Invasive mechanical ventilation is more commonly used in acute respiratory failure patients including poisoning (organophosphate and related compound), ARDS and snake bite (neuroparalytic), whereas, noninvasive mechanical ventilation is commonly used in patients of acute exacerbation of COPD and bronchial asthma.

Key Words: Respiratory failure, mechanical ventilation, invasive ventilator, non invasive ventilator, indications.

 

INTRODUCTION

The respiratory system consists of two parts viz., the gas exchange system (lungs) and the ventilating system (respiratory pump). These can be impaired independently. In pulmonary failure, oxygen therapy is sufficient unless it is accompanied by severe impairment of the gas exchange process, which would then additionally require the application of positive airway pressure. In contrast, dysfunction within the ventilatory system primarily requires mechanical ventilation.1 Patients can get into critical care unit (CCU) because of respiratory failure secondary to pulmonary pathology like pneumonia, status asthmaticus, pulmonary oedema, in many other patients, respiratory failure is secondary to sepsis, cardiac failure or neurological disorders. Mechanical ventilation is indicated when the patient's respiration is inadequate to maintain adequate ventilation. It is also indicated as prophylaxis for imminent collapse of other physiologic functions, or ineffective gas exchange in the lungs.2,3 Noninvasive ventilation (NIV) refers to positive pressure ventilation delivered through a noninvasive interface (nasal mask, facemask, or nasal plugs), rather than an invasive interface (endotracheal tube, tracheostomy). Its use has become more common as its benefits are increasingly recognized.4,5 The present study was carried out to study the indications for invasive and non-invasive mechanical ventilator in patients of respiratory failure.

 

MATERIAL AND METHODS

This prospective observational study was conducted in the intensive respiratory care unit (IRCU) of a tertiary referral and teaching hospital. All critically ill patients admitted to the intensive care unit with respiratory failure during the prescribed study period were considered for case identification. The present study was approved by the institute ethics committee.

Inclusion Criteria

Acute respiratory failure or impending respiratory failure due to:

  • COPD with acute exacerbation
  • Poisonings (Organophosphorus and related compound)
  • Pulmonary oedema
  • ARDS
  • Neuroparalytic snake bite
  • Status asthmaticus
  • Neurological Diseases i.e. Guillaine Bare Syndrome, Meningoencephalitis, Cerebrovascular Accident etc.

Exclusion Criteria

  • Patients of age group <13 years and those admitted in surgical intensive care unit presenting with respiratory failure required mechanical ventilation.
  • Patients who required immediate post operative temporary mechanical ventilation.

Methodology: All included patients were evaluated on the basis of clinical parameters, oxygen saturation monitoring on pulse oximetry to determine the need for mechanical ventilation include following:6,7

Acute Respiratory Failure: At least two of the following criteria should be present:

  • Respiratory distress with dyspnoea
  • Use of accessory muscles of respiration
  • Abdominal paradox
  • Respiratory rate >25/min

Chronic Respiratory Failure (Obstructive lung disease)

  • Fatigue, hypersomnolence, dyspnoea
  • Oxygen saturation <88% for >10% of monitoring time despite O2 supplementation.

Relevant investigations were done in patients on mechanical ventilation in critical care unit. They included complete heamogram including hemoglobin%, complete blood count, Kidney function test, Liver function tests, X-ray chest PA view, ECG, Endotracheal aspirate for culture and sensitivity, Serum electrolyte and Arterial blood gas analysis. In selected cases, whenever necessary specific investigations such as, Sputum for AFB, Blood culture, CSF examination and CT scan (Brain).

Procedure of intubation:8 Based upon anatomical considerations commonly employ the Mallampati scale to evaluate objectively the airway’s suitability for placement of the endotracheal tube. The ability to visualize the soft palate, fauces, tonsillar pillars, and uvula is used to predict the degree of difficulty in exposing the larynx.

Prerequisites for invasive ventilator support via endotracheal tube or tracheostomy tube:6

  • Respiratory rate >35 or <5 breaths/ minute.
  • Exhaustion, with laboured pattern of breathing.
  • Hypoxia - central cyanosis, SaO2 <90% on oxygen or PaO2 <8kPa.
  • Hypercarpnia - PaCO2 > 8kPa
  • Decreasing conscious level
  • Tidal volume < 5ml/kg or Vital capacity <15ml/kg.

Prerequisites for non-invasive ventilation:6

  • Patient is able to cooperate.
  • Patient can control airway and secretions.
  • Adequate cough reflex.
  • Patient is able to co-ordinate breathing with ventilator.
  • Hemodynamically stable.
  • Blood pH>7.1 and PaCO2 <92 mmHg.
  • Improvement in gas exchange, heart rate and respiratory rate within first two hours.
  • Normal functioning gastrointestinal tract.

The recommended initial ventilator settings follow. Adjustments in these ventilator settings may be made according to the patient's clinical situation.

 

Table 1: Initial ventilator settings on invasive mechanical ventilation: 6

FiO2

1.0 initially but then reduces

PEEP

5 cmH2O

Tidal Volume

7-10 ml/kg

Inspiratory Pressure

20 cm H2O (15 cm H2O above PEEP)

Frequency

10 - 15 breaths per minute

Pressure Support

20 cm H2O (15cmH2O above PEEP)

I:E Ratio

1:2

Flow Trigger

2 lit / min

Pressure Trigger

-1 to -3 cmH2O

 

Initial Ventilatory Settings of NIVV:15

  • Initial ventilator setting should be very low ie. IPAP of 6 cm H2O, and EPAP of 2 cm H2O.
  • Increase EPAP by 1-2 cm increments till the patient triggers the ventilator in all his inspiratory efforts.
  • Increase IPAP in small increments, keeping it 4cm H2O above EPAP, to a maximum pressure, which the patient can tolerate without discomfort and major leaks.
  • Titrate pressure to achieve a respiratory rate of <25 breaths/min and Vt >7ml/kg.
  • Increase FiO2 to improve O2 saturation to 90%

 

RESULTS

A total of 216 critically ill Patients admitted in intensive respiratory care unit (IRCU) who developed respiratory failure due to various conditions and diseases were studied for the indications of invasive and non invasive ventilations. Amongst 216 patients of respiratory failure, 135 were male (62.5%) and 81 were female (37.5%). Distribution of patients according to underlying disorder who required mechanical ventilation is shown in Table 2.

 

Table 2: Disease distribution of patients requiring mechanical ventilation

Disease

No. of patients

Percentage (%)

Acute respiratory failure

Poisoning

82

38%

ARDS

44

20.4%

Snake bite

24

11.1%

Acute exacerbation of chronic respiratory failure

COPD

21

9.7%

Bronchial Asthma

5

2.3%

Tuberculosis destroyed Lung

3

1.4%

Coma

Meningoencephalitis

18

8.3%

CVA

9

4.2%

Neuromuscular disease

Guillaine-Bare Syndrome

6

2.8%

Other

Hanging

2

1.9%

Valvular Heart Disease

2

1.9%

Total

216

100%

 Amongst overall 216 patients, common indications for initiation of mechanical ventilation included acute respiratory failure 69.4%, acute exacerbation of chronic respiratory failure 13.4%, coma 12.5%, neuromuscular disease 2.8% and 1.9% were other miscellaneous conditions.

 

Table 3: Indications for invasive mechanical ventilator in studied patients

Disease

No. of Patients

Percentage (%)

Acute Respiratory Failure

Poisoning

82

75.8%

ARDS

32

Snake Bite

24

Acute exacerbation of chronic respiratory failure

COPD

04

3.8%

Bronchial Asthma

01

Tuberculosis Destroyed Lung

02

Coma

Meningoencephalitis

18

14.8%

CVA

09

Neuromuscular diseases

Guillaine-Bare Syndrome

06

3.3%

Others

Hanging

02

2.2%

Valvular Heart Disease

02

Total

182 (84.2%)

100%

Amongst 216 patients, 182 (84.2%) required invasive ventilator. Maximum patients i.e., 138 (75.8%) were of acute respiratory failure (poisoning, ARDS, snake bite).

 

Table 4: Indications for noninvasive mechanical ventilator in studied patients

Disease

No. of Patients

Percentage (%)

Acute Respiratory Failure

Poisoning

-

 

35.3%

ARDS

12 (27.3%)

Snake Bite

-

Acute exacerbation of chronic respiratory failure

COPD

17 (81%)

 

64.7%

Bronchial Asthma

4 (80%)

Tuberculosis Destroyed Lung

1 (33.3%)

Neurological Disease

Meningoencephalitis

-

 

CVA

-

 

Guillain-Bare syndrome

-

 

Other

Hanging

-

 

Valvular Heart Disease

-

 

Total

34 (15.7%)

100%

  Amongst 216 patients of respiratory failure, 34 patients (15.7%) required noninvasive ventilator. Common indications of noninvasive ventilator in present study group was COPD (81%), Bronchial asthma (80%), Tuberculous destroyed lung (33.3%) and ARDS (27.3%).

 

DISCUSSION

For many years, patients who developed respiratory failure had to be put on invasive mechanical ventilation in spite of known impending severe complications. Recently, numerous randomized controlled trials have been carried out on use of non-invasive ventilation (NIV) for patients with respiratory failure of varied etiology, such as, acute exacerbation of chronic obstructive pulmonary disease (COPD), acute cardiogenic pulmonary oedema, hypoxaemic respiratory failure and as an adjunct to weaning patients.9,10 Nowadays, physicians have started to use NIV in patients with respiratory failure as much as possible instead of mechanical ventilation to avoid its complications. In the present study, amongst the total 216 patients, 182 (84.2%) required invasive ventilator. Maximum patients i.e., 138 (75.8%) were of acute respiratory failure (poisoning, ARDS, snake bite). In a study done by Schettino et al,11 for patients with cardiogenic pulmonary edema, acute exacerbation of chronic obstructive pulmonary disease (COPD), acute hypercapnic respiratory failure, post extubation respiratory failure patients and acute hypoxemic respiratory failure, intubation rate was 18%, 24%, 38%, 40% and 60%, respectively. Phua J et al.12 reported that risk of NIV failure was lower in COPD than in other condition (19% vs. 47%) respectively. In a study by Gosavi Rakhi A et al,13 out of 110 patients 22 (20%) patients required invasive ventilation, out of them 6 (16.21%) of COPD, 1 (7.14%) of asthma, 5 (55.55%) of ARDS, 2 (20%) of pneumonia, 2 (33.33%) of pulmonary edema, 6 (20%) of post extubation patients. Due to avoidance of intubation NIPPV does not interfere with the performance of the upper airway including eating, talking and discharge of airway secretions. Evidence collected over the past decade shows that in acute respiratory failure secondary to COPD, application of NIPPV reduces mortality and length of hospital stay. In addition, incidence of ventilator-associated pneumonia, nosocomial infections such as sepsis, sinusitis decreases due to shortening of hospital stay.14,15 Efficiency of NIPPV in the treatment of respiratory failure secondary to COPD has been shown in many published studies.16,17 In present study, the commonest indication for initiation of NIPPV was COPD (81%) followed by Bronchial asthma (80%). Other indications were Tuberculous destroyed lung (33.3%) and ARDS (27.3%). This was similar to the study by Gosavi Rakhi A et al,13 in which the commonest indication was COPD 37 (33.63%) followed by post-extubation 30 (27.27%). Similarly, in studies by Chawla, Rai and Agrawal,18-20 COPD was the commonest indication as 71.4%, 64.4% and 38.1% patients had COPD respectively. The results of this study show that invasive mechanical ventilation is more commonly used in acute respiratory failure patients including poisoning (organophosphate and related compound), ARDS and snake bite (neuroparalytic), whereas, noninvasive mechanical ventilation is commonly used in patients of acute exacerbation of chronic respiratory failure including COPD, bronchial asthma.

 

REFERENCES

  1. Mackenzie I. Core Topic In Mechanical Ventilation. Cambrige University Press 2008. pp. 21.
  2. Pierce LNB. Traditional and Non traditional Modes of Mechanical Ventilation. Crit Care Nurse 2002; 22(4):56-59.
  3. Brown BR. Understanding mechanical ventilation: Indications for and initiation of therapy. J Okla State Med Assoc 1994; 87(8):353-7.
  4. Maheshwari V, Paioli D, Rothaar R, Hill NS. Utilization of noninvasive ventilation in acute care hospitals: a regional survey. Chest 2006; 129:1226.
  5. Demoule A, Girou E, Richard JC, et al. Increased use of noninvasive ventilation in French intensive care units. Intensive Care Med 2006; 32:1747.
  6. Udwadia FE. Criteria for mechanical ventilation, waveforms. In: Principles of Critical Care. 2nd Edition, pg. 309-337.
  7. Sharma UD. Non Invasive Ventilation. The Indian Anaesthetists' Forum - On-Line Journal 2004; Jan 1. Available on http//www.theiaforum.org
  8. Fishman's Pulmonary Diseases and Disorders, 5e Ed. Grippi MA, Elias JA, Fishman JA, Kotloff RM, Pack AI, Senior RM, Siegel MD. New York: McGraw-Hill Medical; 2015.
  9. Brochard L, Mancebo J, Wysocki M, Lofaso F, Conti G, et al. (1995) Noninvasive ventilation for acute exacerbation of chronic obstructive pulmonary disease. N Engl J Med 1995; 333: 817-822.
  10. Peter JV, Moran JL, Phillips-Hughes J, Graham P, Bersten AD. Effect of non-invasive positive pressure ventilation (NIPPV) on mortality in patients with acute cardiogenic pulmonary oedema: A meta-analysis. Lancet 2006; 367:1155-1163.
  11. Schettino G, Altobelli N, Kacmarek RM. Noninvasive positive-pressure ventilation in acute respiratory failure outside clinical trials: experience at the Massachusetts General Hospital. Crit Care Med 2008; 36:441-447.
  12. Phua J, Kong K, Lee KH, Shen L, Lim TK. Non-invasive ventilation in hypercapnic acute respiratory failure due to chronic obstructive pulmonary disease vs. other conditions: Effectiveness and predictors of failure. Intensive Care Med 2005; 31: 533-539.
  13. Gosavi Rakhi A, Kapse Vijaykumar R, Mhaisekar Dilip G, Hashmi Syed F, Anandkumar Babulal L. Indications, Outcome and Complications of Non-Invasive Positive Pressure Ventilation in Acute Respiratory Failure. J Pulm Respir Med 2017; 7: 424.
  14. Singh VK, Khanna P, Rao BK, Sharma SC, Gupta R. Outcome predictors for non-invasive positive pressure ventilation in acute respiratory failure. J Assoc Physicians India 2006; 54: 361-365.
  15. Wysocki M, Antonelli M. Non-invasive mechanical ventilation in acute hypoxaemic respiratory failure. Eur Respir J 2001; 18: 209-220.
  16. Hess DR. Non-invasive positive-pressure ventilation and ventilatorassociated pneumonia. Respir Care 2005; 50: 924-929.
  17. Antonelli M, Conti G, Rocco M. A comparison of Non-invasive positivepressure ventilation and conventional mechanical ventilation in patients with acute respiratory failure. N Engl J Med 1998; 339: 429-435.
  18. Chawla R, Sidhu US, Kumar V, Nagarkar S, Brochard L. Non-invasive ventilation: A survey of practice patterns of its use in India. Indian J Crit Care Med 2008; 12: 4.
  19. Rai SP, Panda BN, Upadhyay KK. Non-invasive positive pressure ventilation in patients with acute respiratory failure. Clin Chest Med 2004; 60: 224- 226.
  20. Agarwal R, Handa A, Aggarwal AN, Gupta D, Behera D. Outcomes of Non-invasive ventilation in acute hypoxemic respiratory failure in a respiratory intensive care unit in north India. Respiratory Care 2009; 54: 12.

 


 


 


 


 


 

 

 


 


 



 


 

 


 

 

 


 


 









Policy for Articles with Open Access
Authors who publish with MedPulse International Journal of Anesthesiology (Print ISSN:2579-0900) (Online ISSN: 2636-4654) agree to the following terms:
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
Authors are permitted and encouraged to post links to their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work.