Table 3. Characteristics of RBC Transfusion Events.
| Variable | Total RBC events (n = 1727)a |
|---|---|
| Time of administration during daytime hours (07:30 am-6:00 pm) | 1063 (62.9) |
| Certification level of transfusion requestor | |
| Intensivist | 1055 (61.1) |
| Resident, specialist in training | 326 (18.8) |
| Specialist nonintensivist practicing ICU | 252 (14.6) |
| Specialist nonintensivist outside ICU | 74 (4) |
| Nurse | 12 (<1) |
| Other | 8 (<1) |
| Student | 0 |
| Primary medical specialty of transfusion requestor | |
| Anesthesiology | 818 (47.7) |
| Intensivistb | 390 (22.7) |
| Internal medicine | 236 (13.8) |
| Surgery | 180 (10.5) |
| Pulmonology | 48 (3) |
| Cardiology | 27 (2) |
| Other (ie, emergency medicine, neurology) | 17 (1) |
| No. of RBC units per event, median (IQR) | 1 (1-2) |
| Hemoglobin levels | |
| Threshold predefined, median (IQR), g/dLc | 8.0 (7.0-9.0) |
| Restrictive (<7 g/dL) | 299 (17.3) |
| Intermediate (7-9 g/dL) | 430 (24.9) |
| Liberal (>9 g/dL) | 459 (26.6) |
| No threshold stated | 539 (31.2) |
| Before transfusion, g/dLd | 7.7 (1.6) |
| Post transfusion, g/dLe | 9.1 (1.5) |
| Hb level increase after transfusion, median (IQR), g/dLf | 1.2 (0.7-2.0) |
| Change in Hb level (between Hb prior and stated Hb threshold), g/dLg | −0.7 (1.5) |
| As part of massive transfusion protocol | 43 (3) |
| Whole blood (no isolated RBC available) | 54 (3) |
| Reason for RBC transfusion (multiple options possible)h | |
| Low Hb value | 1412 (81.8) |
| Active bleeding | 479 (27.7) |
| Hemodynamic instability | 406 (23.5) |
| Improving general state | 142 (8.2) |
| Improving peripheral oxygen | 115 (6.7) |
| (New) coronary ischemia | 69 (4) |
| Presurgery | 67 (4) |
| Age of patient | 60 (4) |
| Other | 47 (3) |
| Improving weaning | 43 (3) |
| Part of clinical trial | 6 (<1) |
| Exchange transfusion | 2 (<1) |
| No. of reasons | 1 (1-2) |
| Trigger for RBC transfusion (multiple options possible)h | |
| Hypotension | 728 (42.2) |
| No physiological trigger affected the decision to transfuse | 682 (39.5) |
| Tachycardia | 474 (27.4) |
| Increased lactate levels (>2 mmol/L) | 308 (17.8) |
| Acidosis | 204 (11.8) |
| Arrhythmia | 70 (4) |
| Other | 66 (4) |
| Venous oxygen saturation <65% | 36 (2) |
| Central venous oxygen saturation <65% | 30 (2) |
| ECG changes | 23 (1) |
| No. of triggers | 1 (1-2) |
Abbreviations: ECG, electrocardiogram; ED, emergency department; Hb, hemoglobin; ICU, intensive care unit; RBC, red blood cell.
Presented as No. (%) for frequency data, median (IQR shown 1st-3rd quartile borders) for non-parametric and mean (SD) for parametric numerical variables.
Intensivist training differs worldwide; whereas in some countries, training starts with another medical specialty (ie, surgery, anesthesiology, internal medicine), some countries offer a special intensivist training program. The latter is hereby noted as intensivist.
The Hb value at which an RBC transfusion is advised as stated in the ICU’s protocol or, in the absence of a protocol, the expert’s opinion for that patient.
The most recent Hb value before the RBC transfusion was administered, within 4 hours prior to the decision to transfuse.
The first Hb level measured after RBC transfusion within 24 hours.
Calculated as the difference between the measured Hb level before and after RBC transfusion.
Calculated as the difference between the measured Hb level before and the Hb threshold. A negative change in Hb level may insinuate protocol adherence (ie, the measured Hb level was below the stated threshold), whereas in case of a positive value, the threshold had not yet been reached.
Factors that contributed to the decision to transfuse, consisting of either clinical reasoning (reasons) or physiological parameters (triggers).