Samenvatting

The effect and methods of changing the norepinephrine syringe on the Intensive Care Unit: a quantitative, observational pilot study
BACKGROUND - The change of a syringe with noradrenalin (NOR) often causes fluctuations in the blood pressure. This nursing intervention occurs often at the Intensive Care Unit (ICU) of the University Medical Centre Groningen (UMCG) in the Netherlands. Among nurses, there is a large variety in the way this intervention is performed. However, it is unclear which method causes the least fluctuation of the blood pressure. Also the accurate fluctuation of the blood pressure before, during and after the syringe changeover, the fluctuation of the blood pressure and the relation between these factors on the ICU of the UMCG is not fully known.
This study provides insight in the current situation on the ICU of the UMCG. This quantitative, observational pilot study investigates the methods of changing the noradrenalin syringe and blood pressure fluctuations before, during and after the syringe change.
MATERIALS AND METHODS - Adult ICU patients that are expected to receive noradrenalin intravenously (IV) for more than 12 hours were included in this study. Blood pressure was measured by a laptop linked to the Philips MP70 monitor next to the bed of the patient. Measurements started 15 minutes before until 15 minutes after the changeover of the syringe. During the changeover, the patient characteristics and used method of the changeover were collected using a case report form (CRF). The baseline mean arterial blood pressure (MAP) was determined by measuring it 5 minutes before the changeover of the syringe (reference value). This value was compared with the MAP-value calculated as the mean of three 5-minute intervals after the syringe change. The statistical analysis was conducted by using a chi-squared test and a Mann-Whitney U test. The fluctuation of the blood pressure (ΔMAP) was defined as the difference between the reference value (MAP) and the maximum value (MAP) in the interval of 5 minutes.
A total of 70 ICU-nurses in 70 different hospitals in the Netherlands were queried in a semi-structured interview about syringe change protocols in the Netherlands.
RESULTS - The study is conducted with a total of 56 observed changeovers at 34 unique, adult patients in the Intensive Care Unit. This total consisted of 16 (47,1%) women and 18 (52,9%) men with a median age of 62 years [57.0-72.0]. Out of 56 syringe changeovers, 20 syringe changeovers caused a small fluctuation (>= 10 mmHg < 20 mmHg). The fluctuations are most common in the period from 0-5 minutes after the changeover. The fluctuations in the blood pressure are ascending and descending. The most common method of changing in the UMCG is the quick changeover. There is a significant statistical difference between small fluctuations in the blood pressure and the method of changing the syringe (p=0,011).
The quick changeover is also the most used method in other ICU’s. The nurses from the other ICU’s based their method of changing the syringe on the hemodynamic instability of the patient and the speed and dose of the noradrenalin. When they think the quick changeover is to riskful, they often use a method with a second pump.
CONCLUSIONS - Fluctuations in the blood pressure are most frequent in the period directly after the syringe changeover. There is no clinical relevance between the method of changing the syringe with noradrenalin and fluctuation of the blood pressure.
RECOMMENDATIONS - Further research is recommended. For example a research with a controlled setting, where the methods of the syringe change will be changed in the course of one year. In this way, one can avoid variations in methods of changing the syringe. Research concerning the profits of a standard method for the noradrenaline syringe change is also recommended.