Search PubMed⌕ Search

Biomedical subjects

M Green

Publications and source records attributed to M Green.

At least 163 records · Page 9Linked to original sources
PubMed1999

The SCID/Beige mouse as a model to investigate protection against Yersinia pestis.

In this study, we have shown that severe combined immunodeficient/beige mice reconstituted with hyperimmune Balb/c lymphocytes can be used as a model to demonstrate adoptive and passive protection against plague infection. Reconstitution of severe combined immunodeficient/beige mice was successful in nine out of ten mice as demonstrated by spleen colonisation and sustained circulating immunoglobulin titres. Furthermore, an increase in antibody titre was evident after a booster immunisation of reconstituted mice. Presence of circulating antibody correlated with protection against a systemic plague challenge and indicated that in reconstituted mice adoptive transfer of a functional immune system had occurred. The severe combined immunodeficient/beige mouse was also used to demonstrate passive protection against inhaled and systemic plague infection. The reconstituted severe combined immunodeficient/beige mouse model demonstrating protective immunity against plague will be further developed to identify the immune cell subsets responsible for this protection.

Adoptive Transfer↗
PubMed1999

Functional magnetic stimulation of the abdominal muscles in humans.

Functional magnetic stimulation (FMS) of the thoracic nerve roots to simulate cough has been suggested as a treatment approach in patients unable to voluntarily activate the abdominal muscles. However, factors that could influence the efficacy of FMS in clinical use have not been evaluated. In the present investigation we studied train length, posture, and frequency to determine the optimal stimulation protocol. We also evaluated the use of a valve at the mouth to enhance glottic function and investigated whether lung volume at the time of stimulation would influence the tension generated by the abdominal muscles. Studies were performed using a Magstim rapid stimulator augmented by four booster packs in nine healthy subjects; we measured the change in gastric (DeltaPga(FMS)), esophageal (DeltaPes(FMS)), and mouth pressure and expiratory flow. With our apparatus pressure generation was maximized by having a train length of at least 300 ms and a frequency of 25 Hz. Posture and valve use were not important determinants of DeltaPga(FMS) or DeltaPes(FMS). Lung volume exerted only a minor influence on DeltaPga(FMS), but the ratio DeltaPes(FMS):DeltaPga(FMS) was increased at TLC compared with FRC. Expiratory flow was increased by adopting a seated posture and using an occlusion valve with an opening threshold close to the maximum DeltaPes(FMS) generated by the stimulus train; however, expiratory flow was susceptible to interference from glottic incoordination. Representative results (with train length 600 ms, 25 Hz, and 100% power, seated) were mean DeltaPga(FMS), 166 cm H(2)O; mean DeltaPes(FMS), 108 cm H(2)O; and mean expiratory flow, 311 L/min. We confirm that FMS of the abdominal muscles can generate a substantial positive intra-abdominal and intrathoracic pressure and, consequently, expiratory flow in normal subjects.

Abdominal Muscles↗
PubMed1999

Diaphragm strength in chronic heart failure.

Reduced respiratory muscle strength has been reported in chronic heart failure (CHF) in several studies. The data supporting this conclusion come almost exclusively from static inspiratory and expiratory mouth pressure maneuvers (MIP, MEP), which many subjects find difficult to perform. We therefore performed a study using measurements that are less dependent on patient aptitude and also provide specific data on diaphragm strength. In 20 male patients and 15 control subjects we measured MIP and MEP as well as esophageal and transdiaphragmatic pressure during maximal sniffs (Sn Pes, Sn Pdi) and cervical magnetic phrenic nerve stimulation (Tw Pdi). In a subgroup the response to paired phrenic nerve stimulation (pTw Pdi) at interpulse intervals from 10 to 200 ms (5 to 100 Hz) was also determined. As expected, MIP was significantly reduced in the CHF group (CHF, 69.5 cm H(2)O; control, 96.7 cm H(2)O; p = 0.01), but differences were much less marked for Sn Pes (CHF, 95.2 cm H(2)O; control, 104.8 cm H(2)O; p = 0.20) and MEP (CHF, 109.1 cm H(2)O; control, 135.7 cm H(2)O; p = 0.09). Diaphragm strength was significantly reduced (Sn Pdi: CHF, 123.8 cm H(2)O; control 143.5 cm H(2)O; p = 0.04. Tw Pdi: CHF, 21.4 cm H(2)O; control, 28.5 cm H(2)O; p = 0.0005). Paired phrenic nerve stimulation suggested a trend to increased twitch summation at 5 to 20 Hz in CHF, although this did not reach significance. We conclude that mild reduction in diaphragm strength occurs in CHF, possibly because of an increased proportion of slow fibers, but overall strength of the respiratory muscles remains well preserved.

Adult↗
PubMed1999

Respiratory muscle strength in Cushing's syndrome.

The effect of Cushing's syndrome on respiratory muscle strength is unknown. Therefore, we studied 10 consecutive patients with severe Cushing's syndrome. The respiratory muscles were assessed using maximal inspiratory and expiratory mouth pressures (MIP, MEP), maximal sniff transdiaphragmatic pressures (max sniff Pdi), and maximal sniff esophageal pressures (max sniff Pes). Maximal quadricep strength was also assessed. The patients demonstrated an overall mean MIP 92 cm H(2)O, SD 19 (mean 105% of predicted; SD, 23%), mean MEP 134 cm H(2)O, SD 35 (mean 99% of predicted; SD, 25%), mean max sniff Pdi 107 cm H(2)O, SD 12 (mean 78% of predicted; SD, 10%) and mean max sniff Pes of 92 cm H(2)O, SD 11 (mean 92% of predicted; SD, 11%). Quadriceps muscle strength was reduced in all 10 patients: mean 26 kg, SD 9 (mean 49% of predicted strength, SD 21%). Respiratory muscle weakness was not found, despite the presence of severe quadriceps impairment. We conclude that major weakness of the respiratory muscles is not usual in Cushing's syndrome.

Adult↗
PubMed1999

Long-term recovery of diaphragm strength in neuralgic amyotrophy.

Diaphragm paralysis is a recognized complication of neuralgic amyotrophy that causes severe dyspnoea. Although recovery of strength in the arm muscles, when affected, is common, there are little data on recovery of diaphragm function. This study, therefore, re-assessed diaphragm strength in cases of bilateral diaphragm paralysis due to neuralgic amyotrophy that had previously been diagnosed at the authors institutions. Fourteen patients were recalled between 2 and 11 yrs after the original diagnosis. Respiratory muscle and diaphragm strength were measured by volitional manoeuvres as maximal inspiratory pressure and sniff transdiaphragmatic pressure. Cervical magnetic phrenic nerve stimulation was used to give a nonvolitional measure of diaphragm strength: twitch transdiaphragmatic pressure. Only two patients remained severely breathless. Ten of the 14 patients had evidence of some recovery of diaphragm strength, in seven cases to within 50% of the lower limit of normal. The rate of recovery was variable: one patient had some recovery after 2 yrs, and the rest took 3 yrs or more. In conclusion, in most patients with diaphragm paralysis due to neuralgic amyotrophy, some recovery of the diaphragm strength occurs, but the rate of recovery may be slow.

Adult↗
PubMed1999

Diaphragm electromyogram measured with unilateral magnetic stimulation.

The purpose of this study was to establish the phrenic nerve conduction time (PNCT) for magnetic stimulation and further assess the relatively new technique of anterior unilateral magnetic stimulation (UMS) of the phrenic nerves in evaluating the diaphragm electromyogram (EMG). An oesophageal electrode was used to record the diaphragm compound muscle action potential (CMAP) elicited by supramaximal percutaneous electrical phrenic nerve stimulation (ES) and UMS from eight normal subjects. The oesophageal electrode used for recording the CMAP was positioned at the level of the hiatus and 3 cm below. The diaphragm CMAP was also recorded from chest wall surface electrodes in five subjects. All of the phrenic nerves could be maximally stimulated with UMS. A clear plateau of the amplitude of the CMAP was achieved for the right and left phrenic nerves. The mean amplitudes of the CMAP recorded from the oesophageal electrode were, for the right side, 0.74+/-0.29 mV (mean+SD) for ES and 0.76+/-0.30 mV for UMS with maximal power output, and for the left side 0.88+/-0.33 mV for ES and 0.80+/-0.24 mV for UMS. PNCT measured by the oesophageal electrode with ES and UMS with maximal output were, for the right side, 7.0+/-0.8 ms and 6.9+/-0.8 ms, respectively, and for the left side 7.8+/-1.2 ms and 7.7+/-1.3 ms, respectively. However, the CMAP recorded from chest wall surface electrodes with UMS was unsuitable for the measurement of PNCT. The results suggest that unilateral magnetic stimulation of the phrenic nerves combined with an oesophageal electrode can be used to assess diaphragmatic electrical activity and measure the phrenic nerve conduction time.

Action Potentials↗
PubMed1999

Potent mast cell degranulation and vascular permeability triggered by urocortin through activation of corticotropin-releasing hormone receptors.

Urocortin (Ucn) is related to corticotropin-releasing hormone (CRH), and both are released in the brain under stress where they stimulate CRH 1 and 2 receptors (CRHR). Outside the brain, they may have proinflammatory actions through activation of mast cells, which are located perivascularly close to nerve endings and degranulate in response to acute psychological stress. Here, we report that a concentration of intradermal Ucn as low as 10 nM induced dose-dependent rat skin mast cell degranulation and increased vascular permeability. This effect appeared to be equipotent to that of calcitonin gene-related peptide and neurotensin. Ucn-induced skin vasodilation was inhibited by pretreatment with the mast cell stabilizer disodium cromoglycate (cromolyn) and was absent in the mast cell-deficient W/Wv mice. The selective nonpeptide CRH receptor 1 antagonist, antalarmin and the nonselective peptide antagonist astressin both reduced vascular permeability triggered by Ucn but not that by Substance P or histamine. In contrast, the peptide antagonist alpha-helical CRH-(9-41) reduced the effect of all three. The vasodilatory effect of Ucn was largely inhibited by pretreatment with H1 receptor antagonists, suggesting that histamine is the major mediator involved in vitro. Neuropeptide depletion of sensory neurons, treatment with the ganglionic blocker hexamethonium, or in situ skin infiltration with the local anesthetic lidocaine did not affect Ucn-induced vascular permeability, indicating that its in situ effect was not mediated through the peripheral nervous system. These results indicate that Ucn is one of the most potent triggers of rat mast cell degranulation and skin vascular permeability. This effect of Ucn may explain stress-induced disorders, such as atopic dermatitis or psoriasis, and may lead to new forms of treatment.

Animals↗
PubMed1998

Novel regions of allelic deletion on chromosome 18p in tumors of the lung, brain and breast.

Lung cancer is now the number one cause of cancer death for both men and women. An age-adjusted analysis over the past 25 years shows that in women specifically, lung cancer incidence is on the rise. It is estimated that 10-20 genetic events including the alteration of oncogenes and tumor suppressor genes will have occurred by the time a lung tumor becomes clinically evident. In an effort to identify regions containing novel cancer genes, chromosome 18p11, a band not previously implicated in disease, was examined for loss of heterozygosity (LOH). In this study, 50 matched normal and NSCLC tumor samples were examined using six 18p11 and one 18q12.3 PCR-based polymorphic markers. In addition, LOH was examined in 29 glioblastoma pairs and 14 paired breast carcinomas. This analysis has revealed potentially two regions of LOH in 18p11 in up to 38% of the tumor samples examined. The regions of LOH identified included a 2 cm area between markers D18S59 and D18S476, and a more proximal, 25 cm region of intermediate frequency between D18S452 and D18S453. These results provide evidence for the presence of one or more potential tumor suppressor genes on the short arm of chromosome 18 which may be involved in NSCLC, brain tumors and possibly breast carcinomas as well.

Alleles↗
PubMed1998

Serial measurement of Epstein-Barr viral load in peripheral blood in pediatric liver transplant recipients during treatment for posttransplant lymphoproliferative disease.

BACKGROUND: Few data are available describing the natural history of the Epstein-Barr virus (EBV) viral load after the diagnosis of EBV-associated posttransplant lymphoproliferative disease (PTLD). Accordingly, we prospectively followed the EBV viral load after the diagnosis of EBV/PTLD in seven pediatric orthotopic liver transplant recipients. METHODS: EBV viral loads were serially measured by quantitative competitive polymerase chain reaction of the peripheral blood from pediatric patients with PTLD and correlated with the clinical course of these children. Viral loads >200 genome copies/10(5) peripheral blood lymphocytes were considered consistent with an increased risk of PTLD. Viral loads <200 obtained during treatment for PTLD were considered evidence of "clearance" of EBV; subsequent loads >200 were considered evidence of virologic "rebound." RESULTS: The mean EBV viral load at the time of diagnosis of PTLD was 1029. All patients "cleared" their EBV viral load during the treatment of PTLD; patient and graft survival in this series was 100%. The mean time to clearance of EBV from the peripheral blood (18.8 days) was similar to the mean time to onset of first rejection (13.8 days). EBV viral load at the time of diagnosis of rejection after PTLD was always <100. A rebound in the EBV viral load to >200 was noted in five of seven patients a median of 3.5 months (range 2.3-13 months) after the diagnosis of EBV/PTLD. However, none of these children has had any evidence of PTLD recurrence. CONCLUSIONS: Clearance of the EBV viral load from the peripheral blood seems to correlate with restoration of the host's immune response as noted both by the regression of the PTLD and the onset of rejection. Late rebound of the EBV viral load is common and does not seem to predict disease recurrence.

Child↗
PubMed1998

Management of posttransplant lymphoproliferative disease in pediatric liver transplant recipients receiving primary tacrolimus (FK506) therapy.

BACKGROUND: Posttransplant lymphoproliferative disease (PTLD) after pediatric liver transplantation has been associated with high mortality rates. METHODS: The present study examined 282 consecutive pediatric liver transplant recipients from October 1989 to June 1996 who received primary tacrolimus immunosuppression. The aim was to determine the incidence of PTLD, management strategies, and patient outcome. RESULTS: The incidence of PTLD was 13% (361282) with a mean age of 5.5+/-0.7 years (range 0.6 to 15) at diagnosis. The average time from transplantation to PTLD was 10.1+/-2.1 months. Initial treatment of PTLD consisted of reduction (3 patients) or discontinuation (33 patients) of tacrolimus and initiation of antiviral therapy (intravenous ganciclovir, 14 patients; intravenous acyclovir, 22 patients; or both, 5 patients). Alpha-interferon was used in four patients (two successfully). One patient also received gamma-interferon, chemotherapy, and radiation for a central nervous system lesion. Chemotherapy was also used in one patient with Burkitt's, whereas one patient with a pulmonary lesion received additional radiation therapy. Three patients received supportive surgery for gastrointestinal involvement, and one patient had a splenectomy for hemolysis. Overall mortality was 22% (8/36) with 5 (14%) PTLD-related deaths (disseminated disease, 4 patients; bowel perforation, 1 patient). Of 31 survivors, 23 had acute rejection at a median time of 24 days after PTLD, with 2 patients developing chronic rejection. One patient required retransplantation. Present immunosuppression consists of tacrolimus monotherapy in 14 patients, tacrolimus/prednisone in 8 patients, and none in 6 patients. CONCLUSION: In summary, PTLD can be successfully treated with reduction of immunosuppression and administration of antiviral agents in most patients. The management of rejection after PTLD requires reassessment of disease status and judicious reintroduction of immunosuppression therapy.

Adolescent↗
PubMed1998

The Canadian Registry of Atrial Fibrillation: a noninterventional follow-up of patients after the first diagnosis of atrial fibrillation.

The Canadian Registry of Atrial Fibrillation (CARAF) is a nondirected, follow-up study of 1,086 patients who are enrolled at 6 centers across Canada at the time of initial electrocardiographically documented diagnosis of atrial fibrillation (AF). Enrollment commenced in 1991 with an intended 10-year follow-up. Comprehensive baseline data, including clinical history, laboratory, and echocardiographic variables were collected. The patients were treated by their own referring physicians and CARAF did not direct their care. Detailed follow-up was performed at 3 months, 1 year, then yearly, with echocardiograms repeated every 2 years. Several studies, which evaluated patient populations, predictors of events, and cardiac structure and functioning, have been performed and are ongoing. Thyroid function was evaluated at baseline, and, of 707 patients evaluated, only 6 patients were found to be hyperthyroid. Symptoms during AF were evaluated and a profile of the types of symptoms and the predictors of symptoms was compiled. Antiarrhythmic drug use is being followed. Sotalol and propafenone were the most commonly used medications, with the use of antiarrhythmic drugs increasing with recurrence of AF. The use of anticoagulants was assessed. The overall use of warfarin was relatively low, but its use increased dramatically with the presence of various risk factors including congestive heart failure, hypertension, and previous stroke. The one risk factor that did not result in increased use of warfarin was hypertension. Therefore, CARAF was able to identify that hypertension appears to be under-recognized and undertreated in its risk for thromboembolic events. CARAF is just now reaching maturity, with the majority of patients having > or=4 years of follow-up. Therefore, extensive investigations are currently under way that will evaluate the baseline characteristics and utilize these as predictors of recurrence of AF, progression to chronicity, and the occurrence of major events such as stroke and death. A very large cohort of patients with serial echocardiograms over 4 years will permit an understanding of the progression of structural and valvular disease. Therefore, CARAF offers a unique opportunity for comprehensive, nondirected follow-up of patients from their initial diagnosis of AF.

Atrial Fibrillation↗
PubMed1998

The cation-binding domain from the alpha subunit of integrin alpha5 beta1 is a minimal domain for fibronectin recognition.

The cation-binding domain from the alpha subunit of human integrin alpha5beta1 was produced as a recombinant protein, alpha5-(229-448). This protein displays a well defined fold with a content of 30-35% alpha-helix and 20-25% beta-strand, based on circular dichroism. The binding of Ca2+ or Mg2+ to alpha5-(229-448) results in a biphasic conformational rearrangement consistent with the occurrence of two classes of cation-binding sites differing by their affinities. The two classes of sites are located in two conformationally independent lobes, as established by a parallel study of two recombinant half-domains (N- and C-terminal) that also adopt stable folds. Upon saturation with divalent cations, alpha5-(229-448) binds an Arg-Gly-Asp (RGD)-containing fibronectin ligand to form a 1:1 complex. Complex formation is associated with a specific conformational adaptation of the ligand, suggesting an induced fit mechanism. In contrast, neither of the half-domains is competent for ligand binding. The alpha5-(229-448)-fibronectin complex is dissociated in the presence of an RGD peptide, as well as of a simple carboxylic acid, suggesting that the RGD aspartyl carboxylate is an essential element that directly interacts with the alpha5 cation-binding domain.

Amino Acid Sequence↗
PubMed1998

Characteristic magnetic resonance imaging entheseal changes of knee synovitis in spondylarthropathy.

OBJECTIVE: To use magnetic resonance imaging (MRI) in patients with rheumatoid arthritis (RA) and spondylarthropathy (SpA) to determine if the primary site of abnormality differs. METHODS: Twenty patients with recent-onset knee effusion (10 with SpA and 10 with RA) were evaluated using fat-suppressed MRI. Knee joint effusion and synovitis were confirmed using ultrasonography. MRI scans were independently scored by 2 observers who were blinded to the patient's diagnosis. RESULTS: All 10 of the SpA patients, but only 4 of the 10 RA patients, had focal peri-entheseal high signal (compatible with fluid or edema) outside the joint (P = 0.01). Six of the SpA patients had bone marrow edema that was maximal at entheseal insertions; in 4 cases this was multifocal. No RA patients showed such an abnormality (P = 0.01). CONCLUSION: Prominent entheseal abnormalities on MRI are a consistent feature of new-onset synovitis in SpA, but are a minor feature of RA. This finding has important implications for the diagnosis, classification, and mechanisms of synovitis in patients with SpA.

Adult↗
PubMed1998

Lack of correlation of MRP and gamma-glutamylcysteine synthetase overexpression with doxorubicin resistance due to increased apoptosis in SV40 large T-antigen-transformed human mesothelial cells.

PURPOSE: Evidence suggests that viral proteins such as simian virus large T-antigen (SV40 TAg) play a role in the response of cancer cells to chemotherapeutic agents. In this study, we investigated whether SV40 TAg-immortalized human mesothelial cells express drug resistance-related proteins and display resistance to chemotherapy, and whether SV40 TAg transformation affects apoptosis. METHODS: We determined the mRNA and protein levels of the multidrug resistance-associated protein (MRP), gamma-glutamylcysteine synthetase heavy subunit (gamma-GCSh), and P-glycoprotein (product of the MDR1 gene) by RT-PCR and Western blotting, respectively, in normal human mesothelial (NHM) cell and SV40 TAg-transformed human mesothelial (Met-5A) cells. The effect of increasing concentrations of doxorubicin (DOX) on these cells was investigated using an MTT cytotoxicity assay, and the glutathione (GSH) content was measured spectrophotometrically. DOX accumulation in these cells was measured by treating the cells with [14C]DOX followed by scintillation counting. Cytoplasmic bNA fragmentation due to apoptosis following DOX treatment of the cells was quantitated by ELISA. RESULTS: We showed that the MRP and gamma-GCSh genes, but not MDR1, are coordinately overexpressed in Met-5A cells compared with NHM cells. Expression of MRP protein as detected by an anti-MRP antibody correlated with increased GSH levels and decreased accumulation of [14C]DOX in Met-5A cells compared with NHM cells. However, Met-5A cells were twofold more sensitive to DOX than NHM cells. In addition, quantitative measurement of apoptosis when cells were treated with 0.05 and 0.5 microM DOX revealed that drug-induced apoptotic cell death was increased about 1.4- and 3.0-fold, respectively, in Met-5A cells compared with NHM cells. CONCLUSIONS: These results suggest that increased levels of apoptosis might help overcome the DOX resistance effects of MRP/gamma-GCSh overexpression in SV40 TAg-transformed Met-5A cells.

ATP-Binding Cassette Transporters↗
PubMed1998

Current status of intestinal transplantation in children.

PURPOSE: A clinical trial of intestinal transplantation (Itx) under tacrolimus and prednisone immunosuppression was initiated in June 1990 in children with irreversible intestinal failure and who were dependent on total parenteral nutrition (TPN). METHODS: Fifty-five patients (28 girls, 27 boys) with a median age of 3.2 years (range, 0.5 to 18 years) received 58 intestinal transplants that included isolated small bowel (SB) (n = 17), liver SB (LSB) (n=33), and multivisceral (MV) (n=8) allografts. Nine patients also received bone marrow infusion, and there were 20 colonic allografts. Azathioprine, cyclophosphamide, or mycophenolate mofetil were used in different phases of the series. Indications for Itx included: gastroschisis (n=14), volvulus (n=13), necrotizing enterocolitis (n=6), intestinal atresia (n=8), chronic intestinal pseudoobstruction (n=5), Hirschsprung's disease (n=4), microvillus inclusion disease (n=3), multiple polyposis (n=1), and trauma [n=1). RESULTS: Currently, 30 patients are alive (patient survival, 55%; graft survival, 52%). Twenty-nine children with functioning grafts are living at home and off TPN, with a mean follow-up of 962 (range, 75 to 2,424) days. Immunologic complications have included liver allograft rejection (n=18), intestinal allograft rejection (n=52), posttransplant lymphoproliferative disease (n=16), cytomegalovirus (n=16) and graft-versus-host disease (n=4). A combination of associated complications included intestinal perforation (n=4), biliary leak (n=3), bile duct stenosis (n=1), intestinal leak (n=6), dehiscence with evisceration (n=4), hepatic artery thrombosis (n=3), bleeding (n=9), portal vein stenosis (n=1), intraabdominal abscess (n=11), and chylous ascites (n=4). Graft loss occurred as a result of rejection (n=8), infection (n=12), technical complications (n=8), and complications of TPN after graft removal (n=3). There were four retransplants (SB, n=1; LSB n=3). CONCLUSIONS: Intestinal transplantation is a valid therapeutic option for patients with intestinal failure suffering complications of TPN. The complex clinical and immunologic course of these patients is reflected in a higher complication rate as well as patient and graft loss than seen after heart, liver, and kidney transplantation, although better than after lung transplantation.

Child, Preschool↗
PubMed1998

Subcutaneous interleukin-2 as initial therapy for patients with extensive small cell lung cancer: a phase II trial of Cancer and Leukemia Group B.

In a prior Cancer and Leukemia Group B (CALGB), 16% of a small cohort of patients with extensive small call lung cancer who had failed to obtain a complete remission with chemotherapy did obtain a complete remission after therapy with interleukin-2 (IL-2). In this current trial, 10 patients with extensive small cell lung cancer who had had no prior therapy were treated with subcutaneous IL-2 as induction therapy and then standard chemotherapy with etoposide/cisplatin. Only one patient experienced an objective response to the IL-2 administered prior to chemotherapy. The factors governing response to IL-2 in the first trial but not in this trial are discussed.

Aged↗
PubMed1998

Intubation success rates improve for an air medical program after implementing the use of neuromuscular blocking agents.

To determine whether the success rate for endotracheal intubation improves after implementing the use of neuromuscular blocking (NMB) agents in an air medical program, this retrospective study analyzed all patients requiring endotracheal intubation at two air medical programs (nurse/paramedic crews) over a 5-year period. Air medical program A, the control group, had employed NMB agents throughout the entire study period. Air medical program B, which did not use NMB agents from July 1, 1989 through June 30, 1992, implemented their use starting July 1, 1992. For program A, the overall intubation success rate was 93.5% (202 successful intubations in 216 patients) and the successful intubations/total attempts ratio was 0.67 (202 of 301). For program B, the overall intubation success rate improved from 66.7% (46 successful intubations in 69 patients) before NMB agent use to 90.5% (57 in 63) after NMB agent use (P = .001). The successful intubations/total attempts ratio increased from 0.36 (51 of 141) prior to NMB agent use to 0.48 (63 of 132) after NMB agent use (P = NS). In comparing the 92 patients who did not receive NMB agents to the 40 patients who did, the intubation success rate increased from 69.6% (64 of 92) to 97.5% (39 of 40) (P < .001) and the successful intubation/total attempts ratio increased from 0.36 (73 of 202) to 0.58 (41 of 71) (P = .007). With the use of NMB agents, program B's overall intubation success rate increased significantly, matching the results of program A.

Adjuvants, Anesthesia↗