Biomedical subjects

Greg I Snell

Publications and source records attributed to Greg I Snell.

6 recordsLinked to original sources

PubMed2007

Lung transplantation.

PURPOSE OF REVIEW: To describe recent advances in lung transplantation relevant to anesthesiologists. RECENT FINDINGS: There is recent literature describing medical, surgical, anesthetic and critical care of lung transplant recipients. SUMMARY: There have been substantial changes in preoperative selection and preparation of lung transplant recipients; these include donation after cardiac death, and improved lung-preservation solutions. Newer immunosuppression regimens have been successfully evaluated in clinical trials. Particular advances in anesthesia include endorsement of fluid restriction in thoracic surgery, greater use of transesophageal echocardiography, and postoperative extracorporeal membrane oxygenation.

Anesthesia↗

PubMed2005

Bronchial hyperresponsiveness and the bronchiolitis obliterans syndrome after lung transplantation.

Because bronchial hyperresponsiveness has been linked to the bronchiolitis obliterans syndrome (BOS), we determined PD(20) methacholine (PD(20(M))), PD(15) hypertonic saline (PD(15(HS))) and their dose-response slopes (DRS(M) and DRS(HS)) in 8 single and 18 double lung transplant recipients within 1 year of lung transplantation and examined the relationship to bronchoalveolar lavage cell profiles and subsequent development of BOS. Twenty-two patients (81%) had a positive methacholine and 6 (25%) a positive hypertonic saline challenge. A positive PD(15(HS)) was associated with an increased risk for BOS at 2 years (odds ratio 12.6, 95% confidence interval 1.3-123.5, p < 0.05), and time to BOS was significantly and negatively related to DRS(HS) (r = -0.5, p < 0.05) - that is, the greater the response, the shorter the time to BOS. Interestingly, DRS(HS) correlated positively with recipient:donor total lung capacity ratio (r = 0.5, p < 0.05), but there was no relationship between either challenge result and airway inflammation. Methacholine hyperresponsiveness is common after lung transplantation but is not prognostic, whereas response to hypertonic saline may reflect recipient:donor size matching and provide useful information regarding the potential for BOS development.

Administration, Inhalation↗

PubMed2004

Human cytomegalovirus load in plasma and bronchoalveolar lavage fluid: a longitudinal study of lung transplant recipients.

BACKGROUND: In lung transplant recipients (LTRs), the measurement of human cytomegalovirus (HCMV) load dynamics in the local environment of the lung allograft may offer distinct advantages over their assessment in the peripheral blood compartment. METHODS: We compared HCMV load in paired bronchoalveolar lavage (BAL) and plasma samples in a prospective cohort of LTRs. RESULTS: In all, 182 paired samples were collected from 41 LTRs. Qualitative findings were concordant for 79.7% of the paired samples (virus load detected or absent in 8.1% and 71.5% of paired samples, respectively). In 35 paired samples (20.3%), HCMV was detected in the BAL but not the plasma sample; the converse was not found for any of the paired samples. HCMV inclusions were histologically detected in the lungs of 8 patients on 9 occasions. HCMV was detected in both BAL and plasma samples on 7 of the 9 occasions and in only the BAL sample on 2 occasions. Application of a threshold virus load in BAL samples, to predict histologically proven HCMV infection, was associated with improved diagnostic sensitivity and specificity. CONCLUSIONS: Quantification of HCMV in the lung allograft correlates with histological detection and, in addition, offers the potential to monitor subclinical viral replication in the lung allograft.

Adolescent↗

PubMed2003

Bronchiolitis obliterans syndrome and early human cytomegalovirus DNAaemia dynamics after lung transplantation.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) remains a major cause of morbidity and mortality after lung transplantation. The major identified risk factors for BOS are acute rejection and human cytomegalovirus (HCMV) infection, the latter despite the use of relatively insensitive and nonspecific measures such as HCMV pneumonitis and HCMV serostatus, respectively. We hypothesized that a more accurate prospective analysis of HCMV reactivation in lung transplant recipients (LTRs) would improve our understanding of the association between HCMV and BOS development. METHODS: In 26 LTRs, HCMV DNAaemia was measured using quantitative polymerase chain reaction at monthly intervals during the initial 6 months posttransplantation. BOS was defined as a sustained irreversible 20% decrease in FEV1 compared with the best baseline FEV1 posttransplantation in the absence of any other cause. RESULTS: Of the 26 LTRs, 23 were assessable with regard to the BOS outcome variable. At a median follow-up of 37 months, 10 patients had developed BOS. During the first 6-month monitoring period, HCMV DNAaemia was detected in 15 of the 23 patients on at least one occasion, and there were 12 episodes of HCMV pneumonitis in eight patients. Episodes of grade A3 or greater acute rejection occurred in eight LTRs, six of whom had been HCMV DNAaemia positive at least once and four of whom also demonstrated HCMV pneumonitis. Our results revealed a strong association between BOS and early HCMV DNAaemia detection (univariate analysis [P=0.002] and freedom from BOS analysis [P=0.006]). CONCLUSION: Early HCMV DNAaemia in LTRs is associated with the development of BOS despite routine ganciclovir prophylaxis.

Adult↗

PubMed2003

Interstitial pneumonitis associated with sirolimus: a dilemma for lung transplantation.

Rapamycin/sirolimus (SR), trade named Rapammune (Wyeth-Ayerst, Sydney, Australia), is a potent immunosuppressive drug associated with myelosuppression, hypertension, hyperlipidemia, and infection. Rapamycin/sirolimus-induced pneumonitis has been described previously in renal transplant recipients, and this report describes a stable heart-lung transplant recipient who developed a pulmonary infiltrate that reversed after ceasing SR therapy. We believe that immunosuppression-induced pneumonitis in a lung allograft is a serious dilemma for lung transplant physicians

Adult↗

PubMed2003

Lung volume reduction surgery in Australia and New Zealand. Six years on: registry report.

BACKGROUND: Lung volume reduction surgery (LVRS) has been shown to improve lung function, exercise performance, and quality of life in highly selected individuals with severe emphysema; however, major questions regarding the efficacy and long-term outcomes of LVRS still remain unanswered. Pending the results of large randomized controlled trials (RCTs), the Australian and New Zealand LVRS Database was created to audit local clinical practice and patient outcomes. AIMS: To review patient selection, surgical activity, and patient outcomes related to LVRS in Australia and New Zealand. METHODS: Prospective data were voluntarily submitted by hospitals performing LVRS in Australia and New Zealand. Preoperative, surgical, perioperative, and follow-up variables were analyzed. RESULTS: Data were collected from 15 hospitals regarding 529 patients. Mean age (+/- SD) at surgery was 63 +/- 7 years. Preoperatively, FEV(1) was 29 +/- 9% predicted, total lung capacity (TLC) was 138 +/- 20% predicted, residual volume (RV) was 250 +/- 64% predicted, and 6-min walk (6MW) distance was 327 +/- 111 m. There has been a reduction in the overall number of cases and hospitals performing LVRS since 1999. Improvements in lung function following LVRS (ie, FEV(1) increase of 38%, RV decrease of 27%, TLC decrease of 17%) and exercise capacity (ie, 6MW distance increase of 24%) appear to be maintained for approximately 3 years. CONCLUSIONS: LVRS continues to be performed in Australia and New Zealand, predominantly in large tertiary teaching hospitals with similar outcomes to those described in the literature. It remains difficult to capture long-term lung function and survival outcomes in this population. Ongoing audit and RCTs are both required to resolve the confusion that still shrouds this procedure.

Australia↗