So whats the deal on saline? Should we continue to use it? I am seeing more and more data on the subject. As an old timer with vents and RT care to begin with I realize that you only get about 1/3rd of the saline that you instill but I am hearing rumors that saline shouldn't be used at all that it leads to infections? I thought improper techinque leads to infections. Lets hear what you all think. Thanks

Never use it routinely. Always have it ready to be used if needed. Keep your patient well humidified and you may not need it at all.

This just in, reviving an old question...

"Saline instillation before tracheal suctioning decreases the incidence of ventilator-associated pneumonia *.
Critical Care Medicine. 37(1):32-38, January 2009.
Caruso, Pedro MD, PhD; Denari, Silvia PhD; Ruiz, Soraia A. L. RT; Demarzo, Sergio E. MD, PhD; Deheinzelin, Daniel MD, PhD

Abstract:
Objectives: To compare the incidence of ventilator-associated pneumonia (VAP) with or without isotonic saline instillation before tracheal suctioning. As a secondary objective, we compared the incidence of endotracheal tube occlusion and atelectasis.

Design: Randomized clinical trial.

Setting and Patients: The study was conducted in a medical surgical intensive care unit of an oncologic hospital. We selected consecutive patients needing mechanical ventilation for >72 hrs. Patients were allocated into two groups: a saline group that received instillation of 8 mL of saline before tracheal suctioning and a control group which did not. VAP was diagnosed based on clinical suspicion and confirmed by bronchoalveolar lavage quantitative culture. The incidence of atelectasis on daily chest radiography and endotracheal tube occlusions were recorded. The sample size was calculated to a power of 80% and a type I error probability of 5%.

Measurements and Main Results: One hundred thirty patients were assigned to the saline group and 132 to the control group. The baseline demographic variables were similar between groups. The rate of clinically suspected VAP was similar in both groups. The incidence of microbiological proven VAP was significantly lower in the saline group (23.5% x 10.8%; p = 0.008) (incidence density/1.000 days of ventilation 21.22 x 9.62; p < 0.01). Using the Kaplan-Meier curve analysis, the proportion of patients remaining without VAP was higher in the saline group (p = 0.02, log-rank test). The relative risk reduction of VAP in the saline instillation group was 54% (95% confidence interval, 18%-74%) and the number needed to treat was eight (95% confidence interval, 5-27). The incidence of atelectases and endotracheal tube occlusion were similar between groups.

Conclusions: Instillation of isotonic saline before tracheal suctioning decreases the incidence of microbiological proven VAP."

They used 8ml. Some of the saline vials now only have 3! So I guess it's 3 per suction episode now.

It's nice that someone did an objective study on this, most every one of the old studies were VERY poor quality. Of course you shouldn't do much of anything without thinking, but I remember when our PICU first went to NO SALINE! I had a kid come from the OR and his breath sounds were clear, but seemed slightly diminished. (difficult to tell diminished on a child coming out of sedation whom you've never heard before) I gave a bolus of saline and got nothing but 3/4 of the saline back, Nurse was mad at me for breaking protocol, 30 minutes later kid starts coughing up TONS of secretions, Thick insipated secretions can line the airways perfectly and not give an audible clue! Humidity is always best, saline is great in moderation for thick secretions!

I mainly use it to clear the suction tubing. I once got the analogy of coughing up sputum, spitting it in the sink and washing it down with water. It doesn't break up or thin it just swirls around. This was from a boss who was against using it. But that does make sense in a way. So I really don't use it much, but I do sometimes. I'm a 13 year RT vet and I've seen it many ways.

This is the old "sputum and saline are immiscable" argument. Give him the analogy that he is super constipated and takes a big hard dump in the toilet. Would he finish, get up and refuse to flush the toilet because water and "his load" are immiscable?

Sorry to be so crude but I am so tired of that silly old analogy.

And going further you really don't want the sputum and the water to mix anyway. Normal physiology has the gel layer riding atop the sol layer (sticky on top of wet). The analogy is of a pea shooter. You can shoot a pea out of a pea shooter better than you can shoot pea soup. If the pea is stick then maybe a bit of spit will unstick it.