Validation of capnodynamic determination of cardiac output by measuring effective pulmonary blood flow: a study in anaesthetised children and piglets.

BACKGROUND: Effective pulmonary blood flow (COEPBF) has recently been validated as a technique for determining cardiac output (CO) in animals of varying sizes. The primary aim of our study was to investigate this new technique in paediatric surgical patients, compared with suprasternal two-dimensional Doppler (COSSD). METHODS: A total of 15 children undergoing cleft lip/palate surgery were investigated. Before the start of surgery, manoeuvres that were anticipated to reduce (increase in PEEP from 3 to 10 cm H2O) and increase (atropine) CO were undertaken. A study in mechanically ventilated piglets was also undertaken under general anaesthesia, measuring COEPBF and pulmonary artery (COTS) flow by ultrasonic probe as the comparator. Bias (Bland-Altman plots) and limits of agreement were assessed for effective pulmonary blood flow and COSSD or COTS. RESULTS: In paediatric patients (median age 8.5 months), overall bias was -8.1 (limits of agreement -82 to +66) ml kg-1 min-1, with a mean percentage error of 48% and a concordance rate of 64%. In the piglet model, overall bias was -1 (-36 to +38) ml kg-1 min-1, with a mean percentage error of 31% and a concordance rate of 95%. CONCLUSIONS: Under controlled experimental conditions, COEPBF is associated with excellent agreement and good trending ability when compared with the gold standard COTS. In the paediatric clinical setting, COEPBF performs well; by contrast, COSSD, an operator- and anatomy-dependent technology, appears less reliable than COEPBF.

Alveolar bone healing accompanied by severe swelling in cleft children treated with bone morphogenetic protein-2 delivered by hydrogel.

BACKGROUND: The use of osteoinductive growth factors may be preferable for alveolar cleft repair because it eliminates the need of bone harvesting. In the present prospective randomised pilot study, patients with alveolar clefts were treated with either bone morphogenetic protein 2 (BMP-2) delivered by a hyaluronan-based hydrogel or autologous bone from the iliac crest. METHODS: Seven patients with cleft lip or cleft lip and palate were included. Computed tomography (CT) was performed preoperatively and 6 months postoperatively. The residual cleft volume was compared with the initial volume. Surgery time, bleeding and hospital stay were compared between the two groups. RESULTS: Four patients were randomised to treatment with BMP-2. A low BMP-2 concentration of 50 µg ml(-1) hydrogel did not induce bone formation in treated patients (n = 2) after 6 months, as seen by CT scans. Therefore, the BMP-2 concentration was raised to 250 µg ml(-1) hydrogel in the subsequently randomised patients (n = 2). Bone formation with volume ratio of 59% and 33% was here verified by CT scans after 6 months. However, a severe gingival swelling appeared during the first week in patients treated with higher BMP-2 doses. In the autologous bone group (n = 3), the volume ratio was 29%, 48%, and 69%. Mean surgery time was 100 min in the BMP-2 group and 123 min in the autologous bone group. The mean hospital stay was 2.75 and 3.33 days, respectively. CONCLUSIONS: BMP-2 at a concentration of 250 µg ml(-1) delivered by a hydrogel can be used to treat alveolar cleft defects with good bone quantity and comparable to autologous bone grafts. However, severe gingival swelling may limit the use of BMP-2 for these patients. Therefore, the study was prematurely closed.

[Recreation of tissue--the plastic surgeon's spring-board in to the 21st century]. / Nyskapa vävnad--plastikkirurgins språngbräda in i 2000-talet.

During recent years, a new field has appeared, in which the principles of life sciences and engineering are applied to the development of methods of regenerating human tissue and organs. Since the emergence of this interdisciplinary field, plastic surgeons have been deeply involved in its development, both in the early stages and in introducing the methods into clinical practice. The article consists in discussion of the possibilities these methods offer and the impact they may have on the field of plastic and reconstructive surgery.

Aetiology of acute epiglottitis in adults.

In order to determine the aetiology of acute epiglottitis in adults, blood cultures, paired sera and a urine sample were obtained from 54 patients with fever and epiglottitis visualized by indirect laryngoscopy or by direct fibreoptic nasolaryngoscopy. Antibodies were determined against the capsular polysaccharide of Haemophilus influenzae type b (Hib), 3 pneumococcal antigens (a mixture of 23 capsular polysaccharides, C-polysaccharide and pneumolysin) and antistreptolysin O. Acute sera were examined by the polymerase chain reaction (PCR) for DNA of Hib and pneumococci. The urine samples were examined for Hib capsular antigen. Blood cultures were positive in 15 patients. In another 16, serology and/or PCR verified the aetiology. Hib was the cause in 14, pneumococci in 12 and group A streptococci in 5 patients. The aetiology remained unknown in 23/54 patients (43%). In conclusion, the addition of serology and PCR to blood cultures doubled the possibilities of verifying the aetiology of acute epiglottitis in adults.

Hyperbaric oxygen therapy for wound complications after surgery in the irradiated head and neck: a review of the literature and a report of 15 consecutive patients.

BACKGROUND: Radiotherapy, which is often used for cancer in the head and neck, leads to damage of tissue cells and vasculature. Surgery in such tissues has an increased complication rate, because wound healing requires angiogenesis and fibroplasia as well as white blood cell activity, all of which are jeopardized. Hyperbaric oxygen therapy (HBO) raises oxygen levels in hypoxic tissue, stimulates angiogenesis and fibroplasia, and has antibacterial effects. METHODS: In this consecutive retrospective study, 15 patients with soft-tissue wounds without signs of healing after surgery in full-dose (64 Gy) irradiated head and neck regions were treated with HBO and adjuvant therapy. The patients in this study were also compared with patients examined in an earlier study, with corresponding wounds treated without HBO. RESULTS: The healing processes seemed to be initiated and accelerated by HBO. In the HBO group, 12 of 15 patients healed completely, 2 patients healed partially, and only 1 patient did not heal at all. There were no life-threatening complications. In the reference group, only 7 of 15 patients with corresponding wounds without signs of healing eventually healed without surgical intervention, and 2 patients had severe postoperative hemorrhage, which in one case was fatal. CONCLUSION: Evaluation of obtained results supports the hypothesis that HBO therapy has a clinically significant effect on initiation and acceleration of healing processes in irradiated soft tissues.