The Perceived Value of Liquid Biopsy: Results From a Canadian Validation Study of Circulating Tumor DNA T790M Testing-Patient's Willingness-to-Pay: A Brief Report

Introduction

Liquid biopsy is recommended to diagnose molecular resistance to targeted therapy in patients with lung cancer. Nevertheless, not all jurisdictions provide funding and patient access. We report patients' perceived value of liquid biopsy in targeted therapy resistance.

Methods

Canadian patients participating in a national EGFR T790M liquid biopsy validation study completed structured interviews measuring perceived value and willingness-to-pay for plasma circulating tumor DNA testing as an alternative to tumor biopsy using open-ended and iterative bidding approaches.

Results

A total of 60 patients with advanced lung cancer participated with a median age of 64 years (range: 31-87 y); 69% were Asian and 45% female. All had received prior EGFR tyrosine kinase inhibitor; 17% also received chemotherapy. All patients preferred to have plasma testing over repeat tumor biopsy. In the context of the Canadian publicly funded system, patients estimated that a median of 300 (interquartile range: 150-800) Canadian dollars was a reasonable price to pay for liquid biopsy. Patients were personally willing to pay a median 100 (interquartile range: 33-350) Canadian dollars.

Conclusions

In a system that covers the cost of standard diagnostic tests, patients with lung cancer indicated high willingness-to-pay out-of-pocket for liquid biopsy in the setting of acquired targeted therapy resistance. Patients have high perceived value of plasma genotyping and prefer it to repeat tumor biopsy.

Multicenter Validation Study to Implement Plasma Epidermal Growth Factor Receptor T790M Testing in Clinical Laboratories

PURPOSE

Plasma detection of EGFR T790M mutations is an emerging alternative to tumor rebiopsy in acquired epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor resistance. Validation of analytical sensitivity and clinical utility is required before routine diagnostic use in clinical laboratories.

PATIENTS AND METHODS

Sixty-three patients with advanced EGFR-mutant lung cancer at 7 Canadian centers, who were being screened for the ASTRIS trial (ClinicalTrials.gov identifier: NCT02474355), participated in this companion study. Plasma T790M mutation was detected using droplet digital polymerase chain reaction, Cobas (Roche Diagnostics, Indianapolis, IN), or next-generation sequencing in 4 laboratories. T790M concordance was assessed between plasma and tumor samples.

RESULTS

Assessment of T790M in tumor biopsy tissue was successful in 81% of patients; 49% had confirmed T790M results (tumor or plasma) for ASTRIS. Plasma testing in this companion study yielded T790M results in 97% of patients; 62% had T790M-positive results, 36% had negative results, and 2% had indeterminate results. Of 38 patients with negative or indeterminate biopsy results, 55% had positive plasma T790M results, increasing the proportion with T790M-positive results to 73%. Sensitivity of plasma T790M testing was 75%. Overall concordance between tissue and plasma was 64%, and concordance among laboratories was 90.3%. Response to osimertinib and duration of therapy were similar irrespective of testing method (overall response rate, 62.5% for tissue, 66.7% for plasma, and 70.6% for both).

CONCLUSION

This multicenter validation study demonstrates that plasma EGFR T790M testing can identify significantly more patients than biopsy alone who may benefit from targeted therapy.

Acceptability of Routine Evaluations Using Patient-Reported Outcomes of Common Terminology Criteria for Adverse Events and Other Patient-Reported Symptom Outcome Tools in Cancer Outpatients: Princess Margaret Cancer Centre Experience

BACKGROUND

Recent studies have demonstrated improved outcomes with real-time patient-reported outcome questionnaires (PRO questionnaires) using questions adapted for patient use from the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE). Outside of the clinical trial setting, limited information exists on factors affecting the completion of PRO questionnaires in routine practice. The primary aim of this prospective cross-sectional study was to evaluate patient willingness to complete PRO questionnaires on a regular basis and to better understand responder biases to improve patient feedback.

MATERIALS AND METHODS

Patients performing PRO-CTCAE toxicity and symptom PRO questionnaires in oncology clinics at Princess Margaret Cancer Centre from 2013 to 2016 were assessed for their willingness to complete PRO questionnaires using a nine-item, tablet-based acceptability survey. Patient-reported characteristics (i.e., age, sex, language, marital status, education, occupation, etc.), cancer type, treatment modalities, and health metrics (i.e., Eastern Cooperative Oncology Group) were also collected. Characteristics were evaluated by logistic regression (odds ratios [OR]) using the primary outcome with prespecified levels of significance for univariate (p ≤ .10), and additional multivariate (p ≤ .05) testing.

RESULTS

A total of 1,792 patients (median age 60 years; range 18-97) with various cancer diagnoses were assessed. A greater proportion of female (56%) and white (74%) respondents with an annual household income of <$100,000 (69%) participated. More than half (58%) of respondents were willing to complete PRO questionnaires at every clinic visit, and a high proportion (77%) found utility in reporting physical and emotional feelings to clinicians using PRO questionnaires. In general, patients did not find that PRO questionnaires made clinic visits more difficult (93%). In uni- and multivariable testing, patients were more willing to complete sleep- and fatigue-related PRO questionnaires relative to chemotoxicity-based PRO questionnaires (OR 1.52; p = .012). Patients aged 40-65 versus 18-40 years were also more likely to report high PRO questionnaire acceptability (OR 1.49; p = .025). Additional patient characteristics such as white ethnicity (OR 1.76), Canada as country of birth (OR 1.66), and English language (OR 2.15) relative to other had higher acceptability on uni- (p < .001) and multivariable (p < .001) analyses. Patients reporting treatment intent as palliative (OR 0.69; p = .0013) or hematological (OR 0.73; p = .027) were less likely to report high PRO questionnaire acceptability on univariable analysis; however, only palliative patients (OR 0.72) maintained this effect on multivariable testing (p = .012). Patients reporting higher health utility scores (per change in .05) also had significantly increased PRO questionnaire acceptability in uni- (OR 1.06; p < .001) and multivariable (OR 1.05; p = .008) analyses. No significant differences in PRO questionnaire acceptability were seen between cancer types, education level, household income, employment status, or treatment modality.

CONCLUSION

Routine assessment using PRO questionnaires is associated with moderate acceptability by patients with cancer. Specific patient characteristics are associated with higher completion willingness. Additional research is necessary to identify factors associated with low acceptability of PRO questionnaires and to develop site-, ethnicity-, and treatment-specific instruments to assess the value of PRO questionnaires for symptom monitoring in clinical practice.

IMPLICATIONS FOR PRACTICE

This study will help to identify the clinical, demographic, and survey characteristics associated with willingness to complete patient-reported outcome questionnaires regularly in the cancer outpatient setting.

Afatinib in patients with metastatic or recurrent HER2-mutant lung cancers: a retrospective international multicentre study

INTRODUCTION

HER2 mutations occur in 1-3% of lung adenocarcinomas. With increasing use of next-generation sequencing at diagnosis, more patients with HER2-mutant tumours present for treatment. Few data are available to describe the clinical course and outcomes of these patients when treated with afatinib, a pan-HER inhibitor.

METHODS

We identified patients with metastatic or recurrent HER2-mutant lung adenocarcinomas treated with afatinib among seven institutions across Europe, Australia, and North America between 2009 and 2017. We determined the partial response rate to afatinib, types of HER2 mutations, duration of response, time on treatment, and survival.

RESULTS

We collected information on 27 patients with stage IV or recurrent HER2-mutant lung adenocarcinomas treated with afatinib. Of 23 patients evaluable for response, three partial responses were noted (13%, 95% confidence interval [CI] 4-33%). In addition, 57% of patients (13/23) had stable disease, and 30% (7/23) had progressive disease. We documented partial responses in patients with HER2 exon 20 insertions, including two with YVMA insertion and one with VAG insertion. Two patients with partial responses were previously treated with trastuzumab and pertuzumab. Median duration of response to afatinib was 6 months (range 5-10); median time on treatment was 3 months (range 1-30) and median overall survival from the date of diagnosis of metastatic or recurrent disease was 23 months (95% CI 18-53 months).

CONCLUSIONS

Afatinib is modestly active in patients with HER2-mutant lung adenocarcinomas, including responses after progression on prior HER2-targeted therapies. However, investigations into the biology of HER2-mutant lung adenocarcinomas and development of better HER2-directed therapies are warranted.

Toxicity of Extended Adjuvant Therapy With Aromatase Inhibitors in Early Breast Cancer: A Systematic Review and Meta-analysis

Background

A number of randomized controlled trials (RCTs) have reported improvement in breast cancer outcomes from extending treatment with aromatase inhibitors (AIs) beyond the initial five years after diagnosis. However, the toxicity profile of extended AIs is uncertain.

Methods

We identified RCTs that compared extended AIs to placebo or no treatment using MEDLINE and a review of abstracts from key conferences between 2013 and 2016. Odds ratios (ORs), 95% confidence intervals (CIs), absolute risks, and the number needed to harm (NNH) were computed for prespecified safety and tolerability outcomes including cardiovascular events, bone fractures, second cancers (excluding new breast cancer), treatment discontinuation for adverse events, and death without recurrence. All statistical tests were two-sided.

Results

Seven trials comprising 16 349 patients met the inclusion criteria. Longer treatment with AIs was associated with increased odds of cardiovascular events (OR = 1.18, 95% CI = 1.00 to 1.40, P = .05, NNH = 122), bone fractures (OR = 1.34, 95% CI = 1.16 to 1.55, P < .001, NNH = 72), and treatment discontinuation for adverse events (OR = 1.45, 95% CI = 1.25 to 1.68, P < .001, NNH = 21). Longer treatment with AIs did not influence the odds of either second malignancy (OR = 0.93, 95% CI = 0.73 to 1.18, P = .56) or deaths without breast cancer recurrence (OR = 1.11, 95% CI = 0.90 to 1.36, P = .34).

Conclusions

Extended treatment with AIs is associated with an increased risk of cardiovascular events and bone fractures. There is no statistically significant increase in deaths without breast cancer recurrence among patients receiving longer treatment with AIs. These data should be taken into account when considering extended adjuvant AIs.

HYPE or HOPE: the prognostic value of infiltrating immune cells in cancer

Interactions between immune and malignant cells have been known to have clinical relevance for decades. The potential for immune control is now being therapeutically enhanced with checkpoint inhibitors and other novel agents to improve outcomes in cancer. The importance of the immune infiltrate as a prognostic marker is increasingly relevant. In this minireview, we present an overview of the immune infiltrate and its spatial organisation, and summarise the prognostic value of immune cells in different cancer types. International collaborative efforts are standardising histopathologic reporting of the immune infiltrate, to allow application of these parameters in the clinical and research settings. In general terms, a 'pro-inflammatory' tumour microenvironment and infiltrating CD8-expressing T lymphocytes are associated with improved clinical outcomes in a broad range of tumour types. The inhibitory function of other immune cells, for example, myeloid-derived suppressor cells and regulatory T cells, appear to have a major role in disrupting the capacity for the immune control of cancers.

Third-Generation Tyrosine Kinase Inhibitors Targeting Epidermal Growth Factor Receptor Mutations in Non-Small Cell Lung Cancer

Sensitizing mutations in the epidermal growth factor receptor (EGFR) predict response to EGFR tyrosine kinase inhibitors (TKIs) and both first- and second-generation TKIs are available as first-line treatment options in patients with advanced EGFR-mutant non-small cell lung cancer. Eventual resistance develops with multiple mechanisms identifiable both upon repeat biopsy and in plasma circulating tumor DNA. The T790M gatekeeper mutation is responsible for almost 60% of cases. A number of third-generation TKIs are in clinical development, and osimertinib has been approved by the US Food and Drug Administration for the treatment of patients with EGFR T790M mutant lung cancer after failure of initial EGFR kinase therapy. Resistance mechanisms are being identified to these novel agents, and the treatment landscape of EGFR-mutant lung cancer continues to evolve. The sequence of EGFR TKIs may change in the future and combination therapies targeting resistance appear highly promising.

The addition of anti-angiogenic tyrosine kinase inhibitors to chemotherapy for patients with advanced non-small-cell lung cancers: A meta-analysis of randomized trials

OBJECTIVES

The role of anti-angiogenic tyrosine kinase inhibitors (AATKI) for patients with non-small-cell lung cancers (NSCLC) is uncertain. We conducted a comprehensive meta-analysis to assess the overall utility of adding AATKI to chemotherapy.

MATERIALS AND METHODS

We included 15 randomized controlled trials (RCTs) of AATKI plus chemotherapy versus chemotherapy involving 7997 patients with advanced NSCLC. Meta-analysis was performed to obtain pooled hazard ratios (HR) for OS and PFS, and pooled odds ratios (OR) for objective response rate (ORR) and grade 3 or greater toxicity. Pre-specified subgroup analyses were performed according to line of chemotherapy, chemotherapeutic regimen and histology.

RESULTS

The addition of AATKI to chemotherapy significantly increased progression-free survival (PFS) (HR 0.83, 95% CI 0.79, 0.87; P<0.00001) and ORR [OR 1.63, 95% CI 1.45, 1.84; P<0.00001], but not overall survival (OS) (HR 0.96, 95% CI 0.91, 1.01; P=0.14). OS benefit was seen in the subset of patients with adenocarcinomas (HR 0.86; 95% CI 0.79, 0.95; P=0.002), especially in the second line setting (HR 0.85; 95% CI 0.76, 0.96; P=0.008). However, both grade ≥3 toxicity (HR 2.08, 95% CI 1.59, 2.73; P<0.00001) and treatment-related deaths (OR 2.37, 95% CI 1.58, 3.56; P<0.0001) were significantly higher with the addition of AATKI.

CONCLUSION

The addition of AATKI to chemotherapy in patients with advanced NSCLC significantly increased PFS and ORR but not OS, and did so at the expense of increased toxicity and treatment-related deaths. Preclinical and translational research in predictive biomarkers are essential for the clinical development of this class of drugs.

Localized malignant pleural mesothelioma with renal metastasis

Localized malignant pleural mesothelioma (LMM) is a rare subset of malignant pleural mesothelioma. Its epidemiology, biology, natural history and optimal treatment are poorly understood. We report a case of LMM treated aggressively with complete surgical resection and adjuvant radiotherapy, but subsequently complicated by local chest wall recurrence and solitary metastasis to the kidney. This case is examined in the context of a small number of cases of LMM in the literature to emphasize the existence of this rare disease entity, their unusual biological behaviour and the need for further tumour molecular and genomic research.

Effects of receptor density on Nociceptin/OrphaninFQ peptide receptor desensitisation: studies using the ecdysone inducible expression system

Pretreatment of the G-protein coupled nociceptin receptor (NOP) with nociceptin/orphaninFQ (N/OFQ) produces desensitisation. The influences of receptor expression and genomic effects are largely unknown. We have used an ecdysone-inducible NOP expression system in a CHO line (CHO INDhNOP) to examine the effects of N/OFQ pretreatment upon receptor density, GTPgamma[35S] binding, cAMP formation and NOP-mRNA. CHO(INDhNOP) induced with 5 and 10 microM PonasteroneA (PonA) for 20 h produced NOP densities (Bmax) of 194 and 473 fmol. mg(-1) protein, respectively. This was accompanied by decreased NOP mRNA. The lower Bmax is typical of the central nervous system. Pretreatment with 1 microM N/OFQ significantly (p < 0.05) reduced Bmax at 5 and 10 microM PonA to 100 and 196 fmol. mg(-1) protein, respectively. There was no change in binding affinity. Along with the reduction in Bmax), potency and efficacy for N/OFQ-stimulated GTPgamma[35S] binding were also reduced (5 microM PonA: pEC50-control = 8.55 +/- 0.06, pretreated = 7.88 +/- 0.07; Emax-control = 3.52 +/- 0.43, pretreated = 2.48 +/- 0.10; 10 microM PonA: pEC50-control = 8.41 +/- 0.18, pretreated = 7.76 +/- 0.03; Emax-control = 5.07 +/- 0.17, pretreated = 3.38 +/- 0.19). For inhibition of cAMP formation, there was a reduction in potency (5 microM PonA: pEC50-control = 9.78 +/- 0.08, pretreated = 8.92 +/- 0.13; 10 microM PonA: pEC50-control = 9.99 +/- 0.07, pretreated = 9.04 +/- 0.14), but there was no reduction in efficacy. In addition, there were 39 and 31% reductions in NOP mRNA at 5 and 10 microM PonA, respectively, but these measurements were made following concurrent N/OFQ challenge and PonA induction. In CHO INDhNOP, we have shown a reduction in cell surface receptor numbers and a reduction in functional coupling after N/OFQ pretreatment. This was observed at pseudo-physiological and supraphysiological receptor densities. Moreover, we also report a reduction in NOP mRNA, but further studies are needed which include 'pulsing' PonA and desensitizing following wash-out.

In vitro pharmacological characterisation of a novel cyclic nociceptin/orphanin FQ analogue c[Cys(7,10)]N/OFQ(1-13)NH (2)

Nociceptin/orphanin FQ (N/OFQ) is the endogenous 17 amino acid peptide ligand for the G(i)-protein-coupled N/OFQ receptor (NOP). In an attempt to improve the metabolic stability of N/OFQ, we have produced a truncated cyclic analogue with cysteine residues at positions 7 and 10, c[Cys(7,10)]N/OFQ(1-13)NH(2) (c[Cys(7,10)]). c[Cys(7,10)], the template N/OFQ(1-13)NH(2) and N/OFQ displaced the binding of [(3)H]N/OFQ to Chinese hamster ovary cells expressing recombinant human NOP (CHO(hNOP)) with pK ( i ) values of 9.98, 9.83 and 9.18, respectively. In addition, c[Cys(7,10)], N/OFQ(1-13)NH(2) and N/OFQ stimulated the binding of guanosine triphosphate gamma [(35)S] to CHO(hNOP) cells with pEC(50)/E (max) (stimulation factor) of 9.16/5.5, 9.11/4.9 and 8.35/5.5, respectively. c[Cys(7,10)], N/OFQ(1-13)NH(2) and N/OFQ inhibited forskolin-stimulated cyclic adenosine monophosphate (cAMP) formation with pEC(50) values of 10.08, 10.11 and 9.78, respectively. All ligands produced complete inhibition of cAMP formation. In both functional assays, c[Cys(7,10)] was a full agonist. In a series of metabolism experiments, incubation of 1 nM c[Cys(7,10)], N/OFQ(1-13)NH(2) and N/OFQ with a rat brain homogenate produced a time-dependent loss of peptide that was greatest for the native peptide N/OFQ. Amidation in N/OFQ(1-13)NH(2) produced some metabolic protection, but this was not significantly improved by further inclusion of c[Cys(7,10)]. In summary, c[Cys(7,10)] is a high-affinity, high-potency full agonist of the NOP receptor. However, we were unable to demonstrate clear metabolic protection.

Beryllium-induced TNF-alpha production is transcription-dependent in chronic beryllium disease

Beryllium (Be)-antigen presentation to Be-specific CD4(+) T cells from the lungs of patients with chronic beryllium disease (CBD) results in T cell proliferation and TNF-alpha secretion. We tested the hypothesis that Be-induced, CBD bronchoalveolar lavage (BAL) T cell, transcription-dependent, TNF-alpha secretion was accompanied by specific transcription factor upregulation. After 6 h of Be stimulation, CBD BAL cells produced a median of 883 pg/ml TNF-alpha (range, 608-1,275 pg/ml) versus 198 pg/ml (range, 116-245 pg/ml) by unstimulated cells. After 12 h CBD BAL cells produced a median of 2,963 pg/ml (range, 99-9,424 pg/ml) TNF-alpha versus 55 pg/ml (range, 0-454) by unstimulated cells. Using real-time RT-PCR, Be-stimulated TNF-alpha production at 6 h was preceded by a 5-fold increase in TNF-alpha pre-mRNA copy number:beta-actin copy number (Be median ratio 0.21; unstimulated median ratio 0.04). The median ratio of mature TNF-alpha mRNA:beta-actin mRNA was upregulated 1.4-fold (Be median ratio 0.17; unstimulated median ratio 0.12). Be exposure in the presence of the transcription inhibitor pentoxifylline (PTX) decreased CBD BAL cell TNF-alpha pre-mRNA levels > 60%, whereas treatment with the mRNA splicing inhibitor 2-aminopurine (2AP) decreased levels 40% relative to Be exposure alone. PTX treatment decreased mature TNF-alpha mRNA levels 50% while 2AP decreased levels > 80%, relative to Be exposure alone. Beryllium exposure specifically upregulated transcription factors AP-1 and NF-kappaB. The data suggest that Be exposure induces transcription-dependent TNF-alpha production, potentially due to upregulation of specific transcription factors.

Pharmacological profile of the cyclic nociceptin/orphanin FQ analogues c[Cys10,14]N/OFQ(1-14)NH2 and c[Nphe1,Cys10,14]N/OFQ(1-14)NH2

In this study we describe the activity of two cyclic nociceptin/orphanin FQ (N/OFQ) peptides; c[Cys(10,14)]N/OFQ(1-14)NH(2) (c[Cys(10,14)]) and its [Nphe(1)] derivative c[Nphe(1),Cys(10,14)]N/OFQ(1-14)NH(2) (c[Nphe(1),Cys(10,14)]) in native rat and mouse and recombinant human N/OFQ receptors (NOP). Cyclisation may protect the peptide from metabolic degradation. In competition binding studies of rat, mouse and human NOP the following rank order pK(i) was obtained: N/OFQ(1-13)NH(2)(reference agonist)>N/OFQ=c[Cys(10,14)]>>c[Nphe(1)Cys(10,14)]. In GTPgamma(35)S studies of Chinese hamster ovary cells expressing human NOP (CHO(hNOP)) c[Cys(10,14)] (pEC(50) 8.29) and N/OFQ(1-13)NH(2) (pEC(50) 8.57) were full agonists whilst c[Nphe(1)Cys(10,14)] alone was inactive. Following 30 min pre-incubation c[Nphe(1)Cys(10,14)] competitively antagonised the effects of N/OFQ(1-13)NH(2) with a pA(2) and slope factor of 6.92 and 1.01 respectively. In cAMP assays c[Cys(10,14)] (pEC(50) 9.29, E(max) 102% inhibition of the forskolin stimulated response), N/OFQ(1-13)NH(2) (pEC(50) 10.16, E(max) 103% inhibition) and c[Nphe(1)Cys(10,14)] (~80% inhibition at 10 microM) displayed agonist activity. In the mouse vas deferens c[Cys(10,14)] (pEC(50) 6.82, E(max) 89% inhibition of electrically evoked contractions) and N/OFQ(1-13)NH(2) (pEC(50) 7.47, E(max) 93% inhibition) were full agonists whilst c[Nphe(1)Cys(10,14)] alone was inactive. c[Nphe(1)Cys(10,14)] (10 microM) competitively antagonised the effects of N/OFQ(1-13)NH(2) with a pK(B) of 5.66. In a crude attempt to assess metabolic stability, c[Cys(10,14)] was incubated with rat brain membranes and then the supernatant assayed for remaining peptide. Following 60 min incubation 64% of the 1 nM added peptide was metabolised (compared with 54% for N/OFQ-NH(2)). In summary, we report that c[Cys(10,14)] is a full agonist with a small reduction in potency but no improvement in stability whilst c[Nphe(1)Cys(10,14)] displays tissue (antagonist in the vas deferens) and assay (antagonist in the GTPgamma(35)S assay and agonist in cAMP assay) dependent activity.

Partial agonist behaviour depends upon the level of nociceptin/orphanin FQ receptor expression: studies using the ecdysone-inducible mammalian expression system

(1) Partial agonism is primarily dependent upon receptor density and coupling efficiency. As these parameters are tissue/model dependent, intrinsic activity in different tissues can vary. We have utilised the ecdysone-inducible expression system containing the human nociceptin/orphanin FQ (N/OFQ) peptide receptor (hNOP) expressed in Chinese hamster ovary cells (CHOINDhNOP) to examine the activity of a range of partial agonists in receptor binding, GTPgamma35S binding and inhibition of adenylyl cyclase studies. (2) Incubation of CHOINDhNOP cells with ponasterone A (PON) induced hNOP expression ([leucyl-3H]N/OFQ binding) of 24, 68, 191 and 1101 fmol mg-1 protein at 1, 2, 5 and 10 microm PON, respectively. At 191 fmol mg-1, protein hNOP pharmacology was identical to that reported for other traditional expression systems. (3) pEC50 values for GTPgamma35S binding ranged from 7.23 to 7.72 (2-10 microm PON) for the partial agonist [Phe1psi(CH2-NH)Gly2]N/OFQ(1-13)-NH2 ([F/G]N/OFQ(1-13)-NH2) and 8.12-8.60 (1-10 microm PON) for N/OFQ(1-13)-NH2 and Emax values (stimulation factor relative to basal) ranged from 1.51 to 3.21 (2-10 microm PON) for [F/G]N/OFQ(1-13)-NH2 and 1.28-6.95 (1-10 microm) for N/OFQ(1-13)-NH2. Intrinsic activity of [F/G]N/OFQ(1-13)-NH2 relative to N/OFQ(1-13)-NH2 was 0.3-0.5. [F/G]N/OFQ(1-13)-NH2 did not stimulate GTPgamma35S binding at 1 microm PON, but competitively antagonised the effects of N/OFQ(1-13)-NH2 with a pKB=7.62. (4) pEC50 values for cAMP inhibition ranged from 8.26 to 8.32 (2-10 microm PON) for [F/G]N/OFQ(1-13)-NH2 and 9.42-10.35 for N/OFQ(1-13)-NH2 and Emax values (% inhibition) ranged from 19.6 to 83.2 for [F/G]N/OFQ(1-13)-NH2 and 40.9-86.0 for N/OFQ(1-13)-NH2. The intrinsic activity of [F/G]N/OFQ(1-13)-NH2 relative to N/OFQ(1-13)-NH2 was 0.48-0.97. (5) In the same cellular environment with receptor density as the only variable, we show that the profile of [F/G]N/OFQ(1-13)-NH2 can be manipulated to encompass full and partial agonism along with antagonism.

Assessment of the activity of a novel nociceptin/orphanin FQ analogue at recombinant human nociceptin/orphanin FQ receptors expressed in Chinese hamster ovary cells

The neuropeptide nociceptin/orphanin FQ (N/OFQ) is the endogenous ligand for the nociceptin receptor (NOP). In an attempt to identify high potency NOP agonists for use in the brain we have compared the activity of a novel N/OFQ analogue [Phe(1)Psi(CH(2)-O)Gly(2)]N/OFQ(1-13)NH(2) ([F/G-O]) with the existing [Phe(1)Psi(CH(2)-NH)Gly(2)]N/OFQ(1-13)NH(2) ([F/G]). Both peptides are modified between the first two N-terminal amino acids and are further compared with the agonist template N/OFQ(1-13)NH(2) in [(3)H]N/OFQ binding, GTPgamma[(35)S] binding and cAMP inhibition studies using Chinese hamster ovary cells expressing the recombinant human NOP. All peptides displaced [(3)H]N/OFQ, stimulated GTPgamma[(35)S] binding and inhibited cAMP formation. In [(3)H]N/OFQ binding and GTPgamma[(35)S] binding the rank order affinity and potency was N/OFQ(1-13)NH(2)>[F/G-O]>[F/G]. In GTPgamma[(35)S] binding [F/G] was a clear partial agonist with intrinsic activity (E(max) stimulation factor, mean+/-SEM, n=4) of 7.75+/-1.02 compared with N/OFQ(1-13)NH(2) of 11.13+/-1.76. The efficacy of [F/G-O] (10.17+/-1.88) approached that of the full agonist N/OFQ(1-13)NH(2). Downstream, at the level of cAMP formation, all peptides were full agonists with the following rank order potency: N/OFQ(1-13)NH(2)>[F/G-O]=[F/G]. The enhanced potency and intrinsic activity of the novel [F/G-O] modification makes this an interesting peptide for further in vivo analysis.

Patient status and time to intubation in the assessment of prehospital intubation performance

Assessment of paramedic endotracheal intubation (ETI) performance often does not account for varied clinical conditions or the time required to complete the procedure.

OBJECTIVE

To demonstrate the utility of patient status and time to intubation (TTI) for evaluating prehospital ETI performance.

METHODS

Paramedic charts were reviewed for the period January-December 1998. Patient clinical status was defined as cardiac arrest (absence of perfusing rhythm) or non-cardiac arrest (presence of perfusing rhythm). Method, route, and success of ETI were noted. The TTI was determined as the elapsed time from on-scene arrival to securing of the endotracheal tube. Time elapsed from on-scene arrival to emergency department arrival was noted for instances of failed ETI. Statistical analysis was performed using chi-square and survival analysis (Kaplan-Meier estimator).

RESULTS

Computer records were available for 26,026 patient contacts. Of 893 documented ETI attempts, 771 (86%) were successful. The ETI success rate was significantly higher (p<0.001) for cardiac arrests (551 of 591, 93.2%) than for non-cardiac arrests (220 of 302, 72.9%). Median TTIs were 5 minutes (95% CI: 5, 5) for cardiac arrests and 17 minutes (95% CI: 14, 20) for non-cardiac arrests; this difference was significant (p<0.001). For non-cardiac arrests, ETI success was significantly (p = 0.002) higher for orotracheal intubation (OTI) (168 of 214, 78.5%) than for nasotracheal intubation (NTI) (52 of 88, 59.1%). Median TTIs were 15 minutes (95% CI: 13, 17) for OTI and 25 minutes (95% CI: 23, 27) for NTI; this difference was significant (p = 0.002). For non-cardiac arrests, the difference i

The use of diltiazem for treating rapid atrial fibrillation in the out-of-hospital setting

STUDY OBJECTIVE

We sought to evaluate the use of intravenous diltiazem for treatment of rapid atrial fibrillation or flutter (RAF) in the out-of-hospital setting.

METHODS

This study is a retrospective review of data with historical control subjects. Data were drawn from out-of-hospital patients reported to a statewide paramedic system who presented with atrial fibrillation or flutter and a ventricular response rate (VRR) of 150 beats/min or greater. The intervention (diltiazem) group included patients who received diltiazem during a 9-month period in 1999. The control group included patients from 1998 who did not receive diltiazem. Patients who were intubated or underwent cardioversion were omitted. Therapeutic response was defined as the occurrence of change to sinus rhythm, reduction of VRR to 100 beats/min or less, or reduction of baseline VRR by 20% or greater. Data were analyzed by using the chi(2) test, the Student's t test, and odds ratios (ORs). A Bonferroni adjusted P value of.005 was used to define statistical significance.

RESULTS

Forty-three patients receiving diltiazem and 27 control subjects were included in the study. The mean total diltiazem dose was 19.8 mg (95% confidence interval 17.8 to 21.8). The diltiazem and control groups did not significantly differ with respect to age; sex; history of atrial fibrillation; prior use of digitalis, beta-blockers, or calcium channel blockers; concurrent out-of-hospital therapies; or baseline VRR or systolic blood pressure (P =.09 to 1.00). The difference in VRR reduction between the diltiazem and control groups was 38 beats/min (95% confidence interval 24 to 52); this difference was statistically significant (P <.001). The mean percentage reduction of VRR in the diltiazem group was -33.1%. The difference in systolic blood pressure change between the diltiazem and control groups was not statistically significant (P =.17). The diltiazem group had a higher prevalence of achieving VRR reduction to 100 beats/min or less than did the control group (OR 22.6; P <.001), of achieving a VRR reduction of 20% or greater (OR 19.3; P <.001), and of achieving overall therapeutic response (OR 19.3; P <.001). Few changed to sinus rhythm in either group (estimated OR 6.3; P =.15). No patients in the diltiazem group required treatment for hypotension, endotracheal intubation, resuscitation from cardiac arrest, or emergency treatment of unstable dysrhythmias.

CONCLUSION

The effects of diltiazem on RAF can be appreciated within the constraints of the out-of-hospital environment. Diltiazem should be considered as a viable field therapy for rate control of RAF.

Equipment for mixed gas and oxygen therapy

The rationale for using the most appropriate equipment to administer oxygen and medical gas mixtures is presented. The emphasis is placed on delivering an appropriate FiO2 for the patient's pathophysiology. The safety systems used to prevent accidental administration of the wrong gas mixture are discussed. The research that supports the use of one device over another is discussed when available. The advantages of high-flow fixed performance equipment are contrasted with low-flow variable performance devices.

Clinical practice guidelines for resuscitation in acute care hospitals

The development of the AHA Guidelines for CPR and ECC and the AARC RACH Clinical Practice Guideline should both be instrumental in improving the performance of RCPs on in-hospital resuscitation teams. The AARC and AHA are assuming important leadership roles in this movement by publishing CPGs for CPR and ECC. RCPs with ACLS training are in a prime position to assume more responsibility on resuscitation teams within acute care facilities. They should be prominent members of the resuscitation team--committed to the entire team's performance--and be actively involved in ACLS training. The first step in that process is to study the current levels of RCP competence in ACLS. Further, RCPs and health-care providers should define the goals of resuscitation in terms of long-term survival, quality of life, and years of useful life after CPR. The cost of inadequate attention to which patients should have DNR orders is a drain on the entire health-care system. Research on the impact of disease categories on CPR outcome should be used to educate physicians, nurses, and RCPs so they can help patients better understand their chances of regaining their pre-CPR quality of life. Successful CPR outcome should be carefully defined using the patient's disease category. Each patient should be individually evaluated for DNR orders. As suggested by Schwenzer, "Patients' perception of their quality of life before and after CPR should guide their and our decisions." However, we must all accept the responsibility for defining the limitations of medical technology and try to determine when CPR is futile.

Emergency ventilation techniques and related equipment

Emergency ventilation techniques used during CPR have been refined over the last 40 years. The methods and equipment for emergency ventilation all have their advantages and disadvantages (Table 5), and the appropriate technique varies with the training and experience of the rescuer. Problems encountered during CPR with victims who have unsecured airways remain unresolved at this time and more work needs to be done. Respiratory care practitioners because of their special training and experience with resuscitation are in an excellent position to make contributions to our knowledge by implementing and publishing relevant clinical studies.

Evaluation of ten manual resuscitators across an operational temperature range of -18 degrees C to 50 degrees C

Because of the temperature extremes encountered during emergency resuscitation and transport in the field, we sought to evaluate the performance and safety of 10 adult resuscitators (5 permanent units: Hope 4, Laerdal, Lifesaver, Mark 3, and PMR; and 5 disposable units: BagEasy, Code Blue, CPR Bag, DMR, and SPUR) across an operational temperature range of -18 degrees C to 50 degrees C.

METHOD

We tested the devices against the American Society for Testing and Materials (ASTM) Standard F-920 and the International Organization for Standardization (ISO) Standard 8382. We tested each resuscitator by using a lung model, the Bio-Tek VT-1 Ventilator Tester.

RESULTS

All of the resuscitators met the ventilation requirements for VT and F (600 mL X 20) and I:E less than 1:1 except the SPUR at -18 degrees C. Standards ASTM F-920 and ISO 8382 specify a fractional delivered oxygen concentration (FDO2) of greater than or equal to 0.85 with attachments and greater than or equal to 0.40 without attachments at oxygen flow of 15 L/min and VE of 7.2 L/min (600 mL X 12). Nine resuscitators met Standards ASTM F-920 and ISO 8382 for FDO2 with attachments at 21 degrees C and 50 degrees C, but only 3 units (Code Blue, DMR, and PMR) passed at -18 degrees C. At 21 degrees C, the Hope 4 had an FDO2 of 0.77 +/- 0.03, which was significantly lower (p less than 0.001) than that of the other 9 resuscitators, all of which were greater than or equal to 0.93. Nine resuscitators met the FDO2 standard without attachments. All 10 resuscitators passed the tests for valve function after contamination with simulated vomitus (at an oxygen flow of 30 L/min) and for backward leakage. At the ventilation pattern recommended by the American Heart Association (AHA) (800 mL X 12) the PMR's mean FDO2 dropped to 0.86 +/- 0.03 because of air leaking into the bag where it attaches to the patient-valve assembly. All 10 resuscitators passed the test for mechanical shock at 21 degrees C and 50 degrees C, but 3 units failed at -18 degrees C.

CONCLUSION

We conclude that only the Code Blue and DMR meet the ASTM and ISO standards for operator-powered adult resuscitators across the operational temperature range of -18 degrees C to 50 degrees C.

Evaluation of ten disposable manual resuscitators

We evaluated the performance and safety of 10 disposable resuscitators -- six adult units: SPUR, Code Blue, 1st Response, Hospitak MPR, CPR Bag, and Pulmanex; and four pediatric units: CPR Bag, 1st Response, Hospitak MPR, and LSP Bag Mask.

METHOD

We tested the devices against the American Society for Testing and Materials (ASTM) Standard F-920. We tested each resuscitator by using a lung model, the Bio-Tek VT-1 Ventilator Tester.

RESULTS

All resuscitators met the ventilation requirements for VT and f (adult: 600 mL x 12/min; child: 300 mL x 20/min and 70 mL x 30/min) and I:E less than 1:1. Standard F-920 specifies a fractional delivered O2 concentration (FDO2) greater than or equal to 0.85 with attachments and greater than or equal to 0.40 without attachments, at oxygen flow of 15 L/min, and VE of 7.2 L (600 mL x 12/min) for adult units and VE of 6 L (300 mL x 20/min) for pediatric units. All 10 resuscitators met standard F-920 for FDO2 with attachments. Nine resuscitators met the FDO2 standard without attachments. The 10 resuscitators passed the test for valve function after contamination with simulated vomitus, at an oxygen flow of 30 L/min, and for backward leakage. Three pediatric resuscitators (1st Response, Hospitak MPR, and LSP Bag Mask) did not pass the pressure-limit requirement of 40 +/- 10 cm H2O. Four resuscitators, Hospitak MPR (adult and pediatric) and CPR Bag (adult and pediatric), were unable to pass the test for mechanical shock (a fall from a height of at least 1 meter).

CONCLUSION

We conclude that only Code Blue, 1st response, Pulmanex (with tube-type reservoir), and SPUR meet ASTM Standard F-920 and are acceptable replacements for permanent resuscitators.

Evaluation of five adult disposable operator-powered resuscitators

We evaluated the performance and safety of five adult disposable operator-powered resuscitators: BagEasy, Bag Mask Resuscitator, Pulmanex, 1st Response, and Stat Blue.

METHOD

We tested the devices against the American Society for Testing and Materials (ASTM) Standard F-920-85. We tested each resuscitator by using it to ventilate a lung model, the Bio-Tek VT-1 Adult Ventilator Tester.

RESULTS

All resuscitators met the requirements of VT 600 mL, f 20/min, and I:E less than 1:1. Standard F-920 specifies a fractional delivered O2 concentration (FDO2) greater than or equal to 0.85 with attachments and greater than or equal to 0.40 without attachments, at oxygen flows of 15 L/min and VE of 7.2 L (600 mL x 12). The Pulmanex with bag reservoir attached had a mean +/- SD FDO2 of 0.74 +/- 0.02, and the other four devices had an FDO2 of 0.93 +/- 0.02. Without attachments only the 1st Response and BagEasy had FDO2 greater than or equal to 0.40. All devices when disabled with simulated vomitus were restored to proper function within 20 s and were functional at O2 flow of 30 L/min. Only the Bag Mask Resuscitator did not pass the drop test. Only the Stat Blue did not pass the back-leak test.

CONCLUSIONS

Although we do not have practical experience with these resuscitators, we conclude that only 1st Response and BagEasy meet the ASTM standard for operator-powered resuscitators and that, of the devices tested, only the 1st Response and BagEasy are acceptable replacements for permanent resuscitators.(ABSTRACT TRUNCATED AT 250 WORDS)

Oxygen delivery performance of four adult resuscitation bags

To determine the fractional delivered oxygen concentrations (FDO2) and the proper functioning of patient valves in adult resuscitation bags, we studied the Laerdal, the PMR 1, the PMR 2, and the Vitalograph resuscitators at various oxygen flowrates and ventilation patterns, with and without reservoirs. The Vitalograph, with new or old reservoir, and the PMR 1 cannot deliver high oxygen concentrations (FDO2 greater than 0.90) and should not be used when high FDO2 is important. The PMR 2 and the Laerdal cannot deliver high oxygen concentrations without reservoirs attached; with reservoirs attached the Laerdal achieves FDO2 greater than 0.98 at a flowrate of 10 l/min, and the PMR 2 achieves FDO2 greater than 0.90 at a flowrate of 15 l/min.

Cooperative education of respiratory therapy students

Cooperative education (coop), applied to respiratory care students at Northeastern University in Boston, Massachusetts since 1974, is designed to enhance self-realization and direction by integrating classroom study with experience in educational, vocational, and cultural learning situations outside the classroom. Achievement of this goal requires a curriculum that allows paid work periods at intervals in the program and acceptance by the institution of responsibility for finding work positions for the students. For students coop education gives reality to learning, increases educational motivation, provides financial aid, and provides useful employment contacts. For the employer it provides a source of labor, facilitates recruitment and retention, and permits better utilization of personnel. For the University it permits more effective use of the physical plant, encourages greater community support, and provides benefits to the faculty. The cooperative education plan offers advantages for respiratory therapy training on both the Association and Baccalaureate level. Successful implementation of the program requires the institution to assume responsibility for integrating the experiential phase into the education process.