Q: Twenty minutes is the recommended turnaround time for a single block frozen section. Are there guidelines for the turnaround time for multiple blocks—for example, multiple simultaneous frozen sections for basal cell carcinomas or head and neck cancers?
A. There is not a formal CAP guideline for turnaround time on multiple block frozen section specimens. The CAP Surgical Pathology Committee’s consensus is that a pathology laboratory should aim for approximately the same turnaround time per specimen—multiplied by the number of specimens and divided by the number of cryostats and available cutters. For example, for a laboratory with two cryostats, the suggested turnaround time for two specimens would still be 20 minutes, whereas for three or four specimens the turnaround time could be as high as 40 minutes.
Andrew L. Folpe, MD
Professor of Laboratory Medicine and Pathology
Member, CAP Surgical
Q. Is literature available regarding testing blood drawn from an intraosseous line?
A. When intravenous access cannot be easily secured, it is acceptable to use blood samples taken from the bone marrow cavity for laboratory analysis and an intraosseous line for infusion of fluids or pharmacological agents.1–6 These methods are primarily used in neonates3 and children following extensive burns,1 severe dehydration,4–5 severe trauma,6 or gross edema.3
Two studies have compared bone marrow blood chemistries1-2 and blood gases2 with venous blood. Both specimens were obtained at about the same time. Good correlation between the bone aspirate and venous samples was obtained for pH, bicarbonate, base excess, PCO2, hematocrit, hemoglobin, urea, creatinine, sodium, and chloride.1-2 Poor correlations were obtained for potassium, PO2, ionized calcium, and glucose.1-2 All patients were hemodynamically stable, so the correlations may vary in other clinical situations. The studies concluded that the bone marrow aspiration specimen is an alternative to the venous specimen when it is difficult to obtain venous blood.
In the United Kingdom, medical personnel are taught the technique for obtaining intraosseous access for fluid or pharmacological therapy in the Advanced Trauma Life Support training course.6 Banerjee, et al., reported that the time required to obtain venous access in the course was significantly longer than for intraosseous access in severely dehydrated children.4 The effectiveness of both therapeutic routes was equal for treating dehydration.4 Intraosseous lines were used in 129 of 23,489 pediatric trauma cases who were more severely injured and had a higher mortality rate than those patients with an intravenous line.6 Animal models have been used to evaluate bone marrow specimens for laboratory tests7–8 and intraosseous lines for fluid therapy.8–9
- Hurren JS. Can blood taken from intraosseous cannulations be used for blood analysis? Burns. 2000;26:727–730.
- Grisham J, Hastings C. Bone marrow aspirate as an accessible and reliable source for critical laboratory studies. Ann Emerg Med. 1991;20:1121–1124.
- Lake W, Emmerson AJB. Use of a butterfly as an intraosseous needle in an oedematous preterm infant. Arch Dis Child Fetal Neonatal Ed. 2003;88:409.
- Banerjee S, Singhi SC, Singh S, et al. The intraosseous route is a suitable alternative to intravenous route for fluid resuscitation in severely dehydrated children. Indian Pediatr. 1994;31:1511–1520.
- Daga SR, Gosavi DV, Verma B. Intraosseous access using butterfly needle. Trop Doct. 1999;29:142–144.
- Smith R, Davis N, Bouamra O, et al. The utilization of intraosseous infusion in the resuscitation of paediatric major trauma patients. Injury. 2005;36:1034–1038.
- Orlowski JP, Porembka DT, Gallagher JM, et al. The bone marrow as a source of laboratory studies. Ann Emerg Med. 1989;18:1348–1351.
- Johnson L, Kissoon N, Fiallos M, et al. Use of intraosseous blood to assess blood chemistries and hemoglobin during cardiopulmonary resuscitation with drug infusions. Crit Care Med. 1999;27:1147–1152.
- Carrera RM, Pacheco AM Jr, Caruso J, et al. Intraosseous hypertonic saline solution for resuscitation of uncontrolled, exsanguinating liver injury in young swine. Eur Surg Res. 2004;36:282–292.
Frederick L. Kiechle, MD, PhD
Department of Pathology
Memorial Regional Hospital
Member, CAP Publications Committee
Member, CAP Special Chemistry