Objective To analyze the common causes of ventilator alarms during mechanical ventilation and their management. Methods A total of 104 ventilator alarms that were not instantly solved by first-line residents but referred to pulmonary therapist and attending physicians during September 2007 and August 2008 in the MICU of our hospital were analyzed retrospectively. Results Of all the 104 ventilator alarms, 27 ( 26%) were due to problems of ventilation circuits; 18 were due to patient effortagainst ventilator secondary to anxiety, horror or pain; 15 were due to inappropriate ventilator parameters;13 were due to airway problems; 5 were due to ventilator malfunction; 4 were due to worsening clinical status; 22 were due to other causes. Conclusion During mechanical ventilation, accurate assessment andprompt management of ventilator alarms are of great importance to patient safety and ventilation efficacy.
Objective To explore the effects of different humidification and heating strategies during non-invasive positive pressure ventilation( NIPPV) in patients with ALI/ARDS. Methods A total of 45 patients with ALI/ARDS were randomly divided into three groups to receive NIPPV with different humidification and heating strategies, ie. Group A ( humidification with a 370 Humidifier without heating) ,group B ( humidification with a 370 Humidifier along with a MR410 Heater) , and group C ( humidification and heating with aMR850 Humidifier, and a RT308 circuit heater) . The changes of air temperature, absolute humidity, relative humidity, sputum thickness and patient comfort were compared between the three groups. Sputum thickness was evaluated with AWSS scoring system. Results After humidification and heating, the air temperature, absolute humidity and AWSS score improved significantly in group B [ elevated from ( 23. 9 ±1. 0) ℃, (9.8 ±1. 3) mg/L and 2. 0 ±0. 7 respectively to ( 30. 3 ±1. 7) ℃, ( 31. 0 ±2. 3)mg/L and ( 3. 0 ±0. 9) respectively, P lt; 0. 001] and group C [ elevated from( 23. 8 ±1. 0) , ( 9. 8 ±1. 5)mg/L and ( 2. 1 ±0. 7) respectively to ( 34. 0 ±1. 1) ℃, ( 43.8 ±2. 5) mg /L and 3. 5 ±1. 0 respectively,P lt; 0. 001] . Air temperature and absolute humidity were significantly higher in group C than those in group B( P lt; 0. 001) . Of all the parameters, only absolute humidity showed a significant improvment in group A [ elevated from( 9. 9 ±1. 6) mg/L to ( 11. 9 ±0. 9) mg/L, P lt; 0. 001] . The degree of comfort in group C was significantly higher than that in group A and B [ 8. 0 ±1. 7 vs 5. 0 ±1. 2 and 3. 0 ±0. 4, respectively, P lt;0. 001] . In group A seven patients were switched to group C because of discomfort, four accepted NIPPV continuously, and two avoided invasive mechanical ventilation eventually. In group B three patients were switched to group C because of intolerance of too much condensed water in the breathing circuit, all of them accepted NIPPV continuously, and one avoided invasive mechanical ventilation eventually. Conclusions Compared with mere humidification or humidification with heating humidifier, humidification with heating humidifier and circuit heating during NIPPV can improve the absolute humidity, air temperature and patient comfort,meanwhile decreasing the sputumthickness of patients with ALI/ARDS.
Objective To compare the efficacy and safety of different airway humidification methods in patients with tracheotomy in weaning process. Methods Twelve patients with tracheotomy in the medical intensive care unit ( MICU) of the First Affiliated Hospital of Sue Yat-sen University fromSeptember 2008 to August 2009 were enrolled in which 45 case /times weaning tests in three different humidification ways were performed( 15 cases in each group) . Wet square gauze method was used in group A and traditional intermittent wet fluid drip method was used in group B. In group C, MR850 humidifier device, RT200 Venturi tube and T tube device were used to perform humidification. Comparisons were carried out between the three groups on sputum viscosity, comfort of patients before and after humidification, length of weaning time, frequencies of irritating coughs and phlegm formation during test period. Sputum viscosity was evaluated by airway secretion score ( AWSS) .Results There was no significant difference of sputum viscosity assessed by AWSS in group A before and after humidification( P gt; 0. 05 ) while AWSS was significantly increased in group B and group C ( P lt;0. 01) , implied that sputum viscosity was significantly lower than that of group A ( P lt;0. 05) . The scores of patients’comfortwere 3. 0 ±0. 4, 5. 0 ±1. 2, and 8. 0 ±1. 7 in groups A, B, and C respectively which mean that the patients in group C felt more comfortable than those in group A and group B ( P lt;0. 01) . Cough frequencies of groups A, B and C per hour were 0. 8,2. 6,and 0. 4 times/hour respectively in which the frequency of group B was significantly higher than those of group A and group C ( P lt;0. 01) . The frequency of phlegm formation in group A was 7 times in 15-times offline record, which was significantly higher than those in group B and group C ( P lt;0. 01) . Conclusions For the patients with tracheotomy in weaning process, MR850 humidifier device, RT200 Venturi tube and T tube device for humidification is superior in reducing sputum viscosity and phlegm formation, improving patient comfort, and reducing the occurrence of irritating cough.