Cough suppression during flexible bronchoscopy using combined sedation with midazolam and hydrocodone: a randomised, double blind, placebo controlled trial

Transbronchial lung cryobiopsy for interstitial lung disease: early experience, learning curve, and the impact of sedation on complication rates at a single centre in Japan

BACKGROUND

Transbronchial lung cryobiopsy (TBLC) has emerged as a promising diagnostic tool for interstitial lung disease (ILD). This study aimed to assess the initial experience, procedural learning curve, and influence of sedative medications on complication rates, particularly bleeding and pneumothorax, in the implementation of a TBLC program for ILD diagnosis.

METHODS

In this retrospective cohort study, we analysed 119 patients who underwent TBLC at Nippon Medical School Hospital from April 2021 to March 2024. Procedural times, complication rates, and histopathological outcomes were evaluated. The learning curve was assessed using cumulative sum (CUSUM) analysis, focusing on procedure time and biopsy yield. The association between sedative medication dosages and bleeding risk was also examined.

RESULTS

The overall diagnostic yield was high, with alveolar tissue obtained in 97.5% of cases and a definitive pathological diagnosis achieved in 81.5% of patients. CUSUM analysis revealed a proficiency threshold at approximately 56 cases, with improved efficiency and biopsy yield in the consolidation phase. Fentanyl dosage was significantly associated with reduced bleeding complications (odds ratio 0.51, 95% confidence interval 0.27-0.97, p = 0.041).

CONCLUSIONS

TBLC is a safe and effective diagnostic tool for ILDs, with a manageable learning curve for procedural efficiency. Sedation, particularly fentanyl dosage, may plays a crucial role in minimizing complications, but further research is needed to clarify this relationship. These findings support the adoption of TBLC as a standard diagnostic approach for ILD and highlight the importance of adequate training and optimized sedation protocols to ensure safety and efficacy in clinical practice.

A prospective observation study of the dynamic monitoring of transcutaneous arterial blood oxygen saturation and carbon dioxide during bronchoscopy

BACKGROUND AND AIMS

Because bronchoscopy is an invasive procedure, sedatives and analgesics are commonly administered, which may suppress the patient's spontaneous breathing and can lead to hypoventilation and hypoxemia. Few reports exist on the dynamic monitoring of oxygenation and ventilation during bronchoscopy. This study aimed to prospectively monitor and evaluate oxygenation and ventilation during bronchoscopy using transcutaneous arterial blood oxygen saturation and carbon dioxide.

METHODS

We included patients who required pathological diagnosis using fluoroscopic bronchoscopy at our hospital between March 2021 and April 2022. Midazolam was intravenously administered to all patients as a sedative during bronchoscopy, and fentanyl was administered in addition to midazolam when necessary. A transcutaneous blood gas monitor was used to measure dynamic changes, including arterial blood partial pressure of carbon dioxide (tcPCO2), transcutaneous arterial blood oxygen saturation (SpO2), pulse rate, and perfusion index during bronchoscopy. Quantitative data of tcPCO2 and SpO2 were presented as mean ± standard deviation (SD) (min-max), while the quantitative data of midazolam plus fentanyl and midazolam alone were compared. Similarly, data on sex, smoking history, and body mass index were compared. Subgroup comparisons of the difference (Δ value) between baseline tcPCO2 at the beginning of bronchoscopy and the maximum value of tcPCO2 during the examination were performed.

RESULTS

Of the 117 included cases, consecutive measurements were performed in 113 cases, with a success rate of 96.6%. Transbronchial lung biopsy was performed in 100 cases, whereas transbronchial lung cryobiopsy was performed in 17 cases. Midazolam and fentanyl were used as anesthetics during bronchoscopy in 46 cases, whereas midazolam alone was used in 67 cases. The median Δ value in the midazolam plus fentanyl and midazolam alone groups was 8.10 and 4.00 mmHg, respectively, indicating a significant difference of p < 0.005. The mean ± standard deviation of tcPCO2 in the midazolam plus fentanyl and midazolam alone groups was 44.8 ± 7.83 and 40.6 ± 4.10 mmHg, respectively. The SpO2 in the midazolam plus fentanyl and midazolam alone groups was 94.4 ± 3.37 and 96.2 ± 2.61%, respectively, with a larger SD and greater variability in the midazolam plus fentanyl group.

CONCLUSION

A transcutaneous blood gas monitor is non-invasive and can easily measure the dynamic transition of CO2. Furthermore, tcPCO2 can be used to evaluate the ventilatory status during bronchoscopy easily. A transcutaneous blood gas monitor may be useful to observe regarding respiratory depression during bronchoscopy, particularly when analgesics are used.

Comparison Between Dexmedetomidine and Midazolam-Fentanyl Combination in Flexible Bronchoscopy: A Prospective, Randomized, Double-blinded Study

BACKGROUND

Dexmedetomidine has acceptable clinical utility for inducing sedation during flexible bronchoscopy. Reducing its dose may not only ameliorate its cardiovascular side effects, but also maintain its clinical usefulness.

METHODS

Patients between 18 and 65 years were randomized to either dexmedetomidine (0.75 µg/kg) or the midazolam-fentanyl group (0.035 mg/kg midazolam and 25 mcg fentanyl). The primary outcome measure was the composite score. Other parameters noted were: oxygen saturation, hemodynamic variables, Modified Ramsay Sedation Score, Numerical Rating Scale (NRS) for pain intensity and distress, Visual Analog Scale score for cough, rescue medication doses, ease of doing bronchoscopy, and patient response 24 hours after bronchoscopy.

RESULTS

In each arm, 31 patients were enrolled. The composite score at the nasopharynx was in the ideal category in 26 patients in dexmedetomidine and 21 in the midazolam-fentanyl group (P=0.007). At the tracheal level, the corresponding values were 24 and 16 (P=0.056). There was no significant difference between the 2 groups regarding the secondary outcome measures except hemodynamic parameters. The mean heart rate in the dexmedetomidine and midazolam-fentanyl groups, respectively, was as follows: at 10 minutes after start of FB (90.10±14.575, 104.35±18.48; P=0.001), at the end of FB (98.39±18.70, 105.94±17.45; P=0.016), and at 10 minutes after end of FB (89.84±12.02, 93.90±13.74; P=0.022). No patient developed bradycardia. Two patients (P=0.491) in the dexmedetomidine group developed hypotension.

CONCLUSION

Low-dose dexmedetomidine (0.75 μg/kg single dose) appears to lead to a better composite score compared with the midazolam-fentanyl combination.

Spray nozzle for topical anaesthesia during flexible bronchoscopy: a randomised controlled trial

Background

The effectiveness of using a spray nozzle to deliver lidocaine for superior topical airway anaesthesia during non-sedation flexible bronchoscopy (FB) remains a topic of uncertainty when compared with conventional methods.

Methods

Patients referred for FB were randomly assigned to receive topical lidocaine anaesthesia via the bronchoscope's working channel (classical spray (CS) group) or through a washing pipe equipped with a spray nozzle (SN group). The primary outcome was cough rate, defined as the total number of coughs per minute. Secondary outcomes included subjective perceptions of both the patient and operator regarding the FB process. These perceptions were rated on a visual analogue scale, with numerical ratings ranging from 0 to 10.

Results

Our study enrolled a total of 126 (61 CS group; 65 SN group) patients. The SN group exhibited a significantly lower median cough rate compared with the CS group (4.5 versus 7.1 counts·min-1; p=0.021). Patients in the SN group also reported less oropharyngeal discomfort (4.5±2.7 versus 5.6±2.9; p=0.039), better tolerance of the procedure (6.8±2.2 versus 5.7±2.7; p=0.011) and a greater willingness to undergo a repeat FB procedure (7.2±2.7 versus 5.8±3.4; p=0.015) compared with those in the CS group. From the operator's perspective, patient discomfort (2.7±1.7 versus 3.4±2.3; p=0.040) and cough scores (2.3±1.5 versus 3.2±2.4; p=0.013) were lower in the SN group compared with the CS group, with less disruption due to coughing observed among those in the SN group (1.6±1.4 versus 2.3±2.3; p=0.029).

Conclusions

This study illustrates that employing a spray nozzle for the delivery of lidocaine provides superior topical airway anaesthesia during non-sedation FB compared with the traditional method.

Impact of Cough Severity on the Diagnostic Yield of Endobronchial Ultrasonography Transbronchial Biopsy with Guide Sheath: A Retrospective Observational Study

Bronchoscopy is an invasive procedure, and patient coughing during examination has been reported to cause patient distress. This study aimed to clarify the relationship between cough severity and diagnostic yield of endobronchial ultrasonography with guide sheath transbronchial biopsy (EBUS-GS-TBB). Data of patients who underwent bronchoscopy at Kyorin University Hospital between April 2019 and March 2022 were retrospectively evaluated. Bronchoscopists assessed the cough severity upon completion of the procedure using a four-point cough scale. Cough severity was included as a predictive factor along with those reportedly involved in bronchoscopic diagnosis, and their impact on diagnostic yield was evaluated. Predictors of cough severity were also examined. A total of 275 patients were enrolled in this study. In the multivariate analysis, the diagnostic group (n = 213) had significantly more 'within' radial endobronchial ultrasound findings (odds ratio [OR] 5.900, p < 0.001), a lower cough score (cough score per point; OR 0.455, p < 0.001), and fewer bronchial generations to target lesion(s) (OR 0.686, p < 0.001) than the non-diagnostic group (n = 62). The predictive factors for severe cough include the absence of virtual bronchoscopic navigation (VBN) and prolonged examination time. Decreased cough severity was a positive predictive factor for successful EBUS-GS-TBB, which may be controlled using VBN and awareness of the procedural duration.

Sedation with Propofol and Propofol-Ketamine (Ketofol) in Flexible Bronchoscopy: A Randomized, Double-Blind, Prospective Study

BACKGROUND

The flexible bronchoscopy procedure, which is performed in awake conditions or under local anesthesia, is a difficult and complicated procedure for patients and physicians. Propofol is a fast-acting sedative-hypnotic anesthetic with a rapid return. Ketamine hydrochloride is a fast-acting general anesthetic producing an anesthetic state characterized by deep analgesia, normal pharyngeal, and laryngeal reflexes.

MATERIALS AND METHOD

The study was planned in a randomized, prospective, and double-blind design. The drug(s) administered by the anesthesiologist was not known to the bronchoscopist and the patient. A total of 64 cases were included in the study (34/propofol, 30/ketamine-propofol (ketofol) group). Group propofol received 0.1 mL/kg propofol, and group ketofol received 0.1 mL/kg ketofol intravenously over approximately 30 seconds. Vital signs, non-invasive blood pressure, peripheral oxygen saturation, and pulse values of all cases were measured three times and were recorded just before the start of the procedure, after entering the trachea, and after the procedure was terminated. The Visual Analogue Scale (VAS) and The Ramsay scoring were additionally used in the present study.

RESULTS

Statistically significant differences were detected between the groups in terms of blood pressure and heart rates. Statistically significant differences were detected between the two groups according to The VAS scoring and additional dose requirement.

CONCLUSION

It must be noted that flexible bronchoscopy procedures, which are performed with local anesthesia by both the patient and the physician with a high degree of difficulty, especially combined drugs to be applied with anesthesia support, are more effective/comfortable/reliable, and have fewer complications and higher tolerability if there are no contraindications.

Impact of adding pethidine on disinhibition during bronchoscopy with midazolam: a propensity score matching analysis

BACKGROUND

We sometimes experience disinhibition during bronchoscopy with sedation. However, the impact of adding pethidine on disinhibition has not yet been investigated. This study aimed to examine the additive impact of pethidine on disinhibition during bronchoscopy with midazolam.

METHODS

This retrospective study involved consecutive patients who underwent bronchoscopy between November 2019 and December 2020 (sedated with midazolam: Midazolam group) and between December 2020 and December 2021 (sedated with midazolam plus pethidine: Combination group). The severity of disinhibition was defined as follows: moderate, disinhibition that always needed restraints by assistants; and severe, disinhibition that needed antagonization of sedation by flumazenil to continue bronchoscopy. One-to-one propensity score matching was used to match baseline characteristics between both groups.

RESULTS

After propensity score matching with depression, the type of bronchoscopic procedure, and the dose of midazolam, 142 patients matched in each group. The prevalence of moderate-to-severe disinhibition significantly decreased from 16.2% to 7.8% (P = 0.028) in the Combination group. The Combination group had significantly better scores for sensation after bronchoscopy and feelings toward bronchoscopy duration than did the Midazolam group. Although the minimum SpO₂ during bronchoscopy was significantly lower (88.0 ± 6.2 mmHg vs. 86.7 ± 5.0 mmHg, P = 0.047) and the percentage of oxygen supplementation significantly increased (71.1% vs. 86.6%, P = 0.001) in the Combination group, no fatal complications were observed.

CONCLUSIONS

Adding pethidine could reduce disinhibition occurrence in patients undergoing bronchoscopy with midazolam, with better subjective patient outcomes during and after bronchoscopy. However, whether more patients may need oxygen supplementation and whether hypoxia occurs during bronchoscopy should be considered.

CLINICAL TRIAL REGISTRATION

UMIN000042635.

The utility of a multi-orifice epidural catheter when using the "Spray-as-You-Go" technique for topical Airway Anesthesia during Flexible Bronchoscopy, a randomised trial

BACKGROUND

Lidocaine administered through the working channel of a flexible bronchoscope can provide effective local anesthesia but cannot achieve good distribution in the airway. This study was undertaken to determine whether lidocaine delivered via a multi-orifice epidural catheter (three orifices/openings) is superior to conventional method and if a better distribution and decreased the cough reflex can be achieved.

METHODS

The patients (N = 100; 50 in each group) were randomized to receive either topical airway anesthesia by the "spray-as-you-go" technique via conventional application (group C) through the working channel of the bronchoscope or via a triple-orifice epidural catheter (group E). The primary outcome measurement was the cough severity, which was documented using a 4-point scale. Bronchoscopists and nurses assessed the coughing. The visual analogue scale (VAS) score for cough, total consumption of propofol and lidocaine, requirement frequency of propofol and topical anesthesia, PACU retention time, and adverse events were also compared.

RESULTS

There was a significant difference in the median cough severity scores between the two groups (group C: 3 vs. group E: 2, P = 0.004). The median visual analogue scale (VAS) scores for the cough, were significantly higher in group C than those in group E (bronchoscopist: 3 vs. 2 P = 0.002; nurse: 3 vs. 2, P < 0.001). The incidence of cough was significantly higher in group C in the trachea, left and right bronchi. The highest respiratory rate was higher in group C than in group E (P < 0.01). Eight patients in group C and two patients in group E had an oxygen saturation below 90% during flexible bronchoscopy(FB) (P = 0.046). More patients in group C required extra topical anesthesia than in group E (P < 0.001). The total lidocaine consumption was also higher in group C than that in group E (P < 0.001).

CONCLUSIONS

Endotracheal topical anesthesia via the multi-orifice epidural catheter (three holes/openings) during flexible bronchoscopy using the "spray-as-you-go" technique was appeared to be superior to the conventional method.

Efficacy and safety of remimazolam besylate in bronchoscopy for adults: A multicenter, randomized, double-blind, positive-controlled clinical study

Background: With the development of fiberoptic bronchoscopy in the diagnosis and treatment of various pulmonary diseases, the anesthesia/sedation requirements are becoming more demanding, posing great challenges for patient safety while ensuring a smooth examination/surgery process. Remimazolam, a brand-new ultra-short-acting anesthetic, may compensate for the shortcomings of current anesthetic/sedation strategies in bronchoscopy.

Methods: This study was a prospective, multicenter, randomized, double-blind, parallel positive controlled phase 3 clinical trial. Subjects were randomized to receive 0.2 mg/kg remimazolam besylate or 2 mg/kg propofol during bronchoscopy to evaluate the efficacy and safety of remimazolam.

Results: A total of 154 subjects were successfully sedated in both the remimazolam group and the propofol group, with a success rate of 99.4% (95%CI of the adjusted difference −6.7 × 10%–6% to −5.1 × 10%–6%). The sedative effect of remimazolam was noninferior to that of propofol based on the prespecified noninferiority margin of −5%. Compared with the propofol group, the time of loss of consciousness in the remimazolam group (median 61 vs. 48s, p < 0.001), the time from the end of study drug administration to complete awakening (median 17.60 vs. 12.80 min, p < 0.001), the time from the end of bronchoscopy to complete awakening (median 11.00 vs. 7.00 min, p < 0.001), the time from the end of study drug administration to removal of monitoring (median 19.50 vs. 14.50 min, p < 0.001), and the time from the end of bronchoscopy to removal of monitoring (median 12.70 vs. 8.60 min, p < 0.001) were slightly longer. The incidence of Adverse Events in the remimazolam group and the propofol group (74.8% vs. 77.4%, p = 0.59) was not statistically significant, and none of them had Serious Adverse Events. The incidence of hypotension (13.5% vs. 29.7%, p < 0.001), hypotension requiring treatment (1.9% vs. 7.7%, p = 0.017), and injection pain (0.6% vs. 16.8%, p < 0.001) were significantly lower in the remimazolam group than in the propofol group.

Conclusion: Moderate sedation with 0.2 mg/kg remimazolam besylate is effective and safe during bronchoscopy. The incidence of hypotension and injection pain was less than with propofol, but the time to loss of consciousness and recovery were slightly longer.

Clinical Trial Registration:clinicaltrials.gov, ChiCTR2000039753

Indian Guidelines on Nebulization Therapy

Inhalational therapy, today, happens to be the mainstay of treatment in obstructive airway diseases (OADs), such as asthma, chronic obstructive pulmonary disease (COPD), and is also in the present, used in a variety of other pulmonary and even non-pulmonary disorders. Hand-held inhalation devices may often be difficult to use, particularly for children, elderly, debilitated or distressed patients. Nebulization therapy emerges as a good option in these cases besides being useful in the home care, emergency room and critical care settings. With so many advancements taking place in nebulizer technology; availability of a plethora of drug formulations for its use, and the widening scope of this therapy; medical practitioners, respiratory therapists, and other health care personnel face the challenge of choosing appropriate inhalation devices and drug formulations, besides their rational application and use in different clinical situations. Adequate maintenance of nebulizer equipment including their disinfection and storage are the other relevant issues requiring guidance. Injudicious and improper use of nebulizers and their poor maintenance can sometimes lead to serious health hazards, nosocomial infections, transmission of infection, and other adverse outcomes. Thus, it is imperative to have a proper national guideline on nebulization practices to bridge the knowledge gaps amongst various health care personnel involved in this practice. It will also serve as an educational and scientific resource for healthcare professionals, as well as promote future research by identifying neglected and ignored areas in this field. Such comprehensive guidelines on this subject have not been available in the country and the only available proper international guidelines were released in 1997 which have not been updated for a noticeably long period of over two decades, though many changes and advancements have taken place in this technology in the recent past. Much of nebulization practices in the present may not be evidence-based and even some of these, the way they are currently used, may be ineffective or even harmful. Recognizing the knowledge deficit and paucity of guidelines on the usage of nebulizers in various settings such as inpatient, out-patient, emergency room, critical care, and domiciliary use in India in a wide variety of indications to standardize nebulization practices and to address many other related issues; National College of Chest Physicians (India), commissioned a National task force consisting of eminent experts in the field of Pulmonary Medicine from different backgrounds and different parts of the country to review the available evidence from the medical literature on the scientific principles and clinical practices of nebulization therapy and to formulate evidence-based guidelines on it. The guideline is based on all possible literature that could be explored with the best available evidence and incorporating expert opinions. To support the guideline with high-quality evidence, a systematic search of the electronic databases was performed to identify the relevant studies, position papers, consensus reports, and recommendations published. Rating of the level of the quality of evidence and the strength of recommendation was done using the GRADE system. Six topics were identified, each given to one group of experts comprising of advisors, chairpersons, convenor and members, and such six groups (A-F) were formed and the consensus recommendations of each group was included as a section in the guidelines (Sections I to VI). The topics included were: A. Introduction, basic principles and technical aspects of nebulization, types of equipment, their choice, use, and maintenance B. Nebulization therapy in obstructive airway diseases C. Nebulization therapy in the intensive care unit D. Use of various drugs (other than bronchodilators and inhaled corticosteroids) by nebulized route and miscellaneous uses of nebulization therapy E. Domiciliary/Home/Maintenance nebulization therapy; public & health care workers education, and F. Nebulization therapy in COVID-19 pandemic and in patients of other contagious viral respiratory infections (included later considering the crisis created due to COVID-19 pandemic). Various issues in different sections have been discussed in the form of questions, followed by point-wise evidence statements based on the existing knowledge, and recommendations have been formulated.

Randomized single-blind comparative study of the midazolam/pethidine combination and midazolam alone during bronchoscopy

Background

Bronchoscopy can be a distress for the patient. There have been few studies on the combination of sedatives and opioids. The aim of this study was to demonstrate the usefulness and safety of administration of the combination of midazolam and pethidine during bronchoscopy.

Methods

In this prospective randomized single (patient)-blind study, we randomly assigned 100 patients who were scheduled to undergo bronchoscopy biopsy to receive treatment with either the midazolam/pethidine combination (combination group) or midazolam alone (midazolam group) during examinations. After the end of bronchoscopy, patients completed a questionnaire and the visual analogue scale was measured. The primary outcome was the patients’ acceptance of re-examination assessed by visual analogue scale. We also assessed pain levels, vital signs, midazolam use, xylocaine use, and adverse events. Univariate analyses were performed using Fisher’s exact test for categorical data, and the t-test or Mann-Whitney test was carried out for analysis of numeric data. All P-values were two-sided, and values < 0.05 were considered statistically significant.

Results

We analyzed 47 patients in the combination group and 49 patients in the midazolam group. The primary outcome was a good trend in the combination group, but not significantly different (3.82 ± 2.3 in combination group versus 4.17 ± 2.75 in midazolam alone, P = 0.400). In the combination group, the visual analog scale score for pain during bronchoscopy was significantly lower (1.10 ± 1.88 versus 2.13 ± 2.42, P = 0.022), and the sedation level score per the modified observer’s assessment of alertness/sedation scale was significantly deeper (3.49 ± 0.98 versus 3.94 ± 1.03, P = 0.031). Maximal systolic blood pressure during testing was significantly lower (162.39 ± 23.45 mmHg versus 178.24 ± 30.24 mmHg, P = 0.005), and the number of additional administrations of midazolam was significantly lower (2.06 ± 1.45 versus 2.63 ± 1.35, P = 0.049). There were also significantly fewer adverse events (30 versus 41, P = 0.036).

Conclusions

The combination uses of midazolam and pethidine for sedation resulted in significant improvements in the pain, blood pressure, additional use of midazolam, and safety during bronchoscopy among patients.

Trial registration

This study was registered in the University Medical Hospital Information Network in Japan (UMINCTR Registration number: UMIN000032230, Registered: 13/April/2018).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09640-y.

Identification of the source events for aerosol generation during oesophago-gastro-duodenoscopy

OBJECTIVE

To determine if oesophago-gastro-duodenoscopy (OGD) generates increased levels of aerosol in conscious patients and identify the source events.

DESIGN

A prospective, environmental aerosol monitoring study, undertaken in an ultraclean environment, on patients undergoing OGD. Sampling was performed 20 cm away from the patient's mouth using an optical particle sizer. Aerosol levels during OGD were compared with tidal breathing and voluntary coughs within subject.

RESULTS

Patients undergoing bariatric surgical assessment were recruited (mean body mass index 44 and mean age 40 years, n=15). A low background particle concentration in theatres (3 L-1) enabled detection of aerosol generation by tidal breathing (mean particle concentration 118 L-1). Aerosol recording during OGD showed an average particle number concentration of 595 L-1 with a wide range (3-4320 L-1). Bioaerosol-generating events, namely, coughing or burping, were common. Coughing was evoked in 60% of the endoscopies, with a greater peak concentration and a greater total number of sampled particles than the patient's reference voluntary coughs (11 710 vs 2320 L-1 and 780 vs 191 particles, n=9 and p=0.008). Endoscopies with coughs generated a higher level of aerosol than tidal breathing, whereas those without coughs were not different to the background. Burps also generated increased aerosol concentration, similar to those recorded during voluntary coughs. The insertion and removal of the endoscope were not aerosol generating unless a cough was triggered.

CONCLUSION

Coughing evoked during OGD is the main source of the increased aerosol levels, and therefore, OGD should be regarded as a procedure with high risk of producing respiratory aerosols. OGD should be conducted with airborne personal protective equipment and appropriate precautions in those patients who are at risk of having COVID-19 or other respiratory pathogens.

Clinical usefulness of intermediate-dose dexmedetomidine (0.75 μg/kg) in flexible bronchoscopy - A prospective, randomized, double-blinded study

BACKGROUND:

Dexmedetomidine, although an effective drug for conscious sedation during flexible bronchoscopy, has occasional side effects on the cardiovascular system which need to be addressed.

MATERIALS AND METHODS:

Patients between 18 and 65 years, requiring diagnostic flexible bronchoscopy, found eligible, after screening, were randomized to either receive 0.75 μg/kg intravenous dexmedetomidine over 10 min or intravenous midazolam 0.035 mg/kg over 1 min. Composite score was used as the primary outcome measure. Additional parameters recorded were: Hemodynamic variables, oxygen saturation, Ramsay sedation score, for pain intensity and distress Numerical Rating Scale, number of rescue medication doses, ease of doing bronchoscopy, Visual Analog Scale score for cough and response of the patient 24 h after bronchoscopy.

RESULTS:

In each group, 24 patients were enrolled. The composite score was in the ideal category in 24 patients in dexmedetomidine group and 21 in midazolam group, at nasopharynx (P = 0.234). The corresponding values at the level of trachea were 23 and 16 (P = 0.023). In dexmedetomidine group, patient response after 24 h of bronchoscopy showed quality of sedation to be excellent in 0 subjects, good in 13, fair in 9 and poor in 2 and discomfort to be nil in 7, mild 10, moderate in 7 and severe in 0. The corresponding values in midazolam group for quality of sedation were 0, 4, 14, 6, and for discomfort 0, 10, 14, 0. The Visual Analog Scale (VAS) for cough revealed a mean score of 0.800 and 1.812 (P = 0.011) during and 2.092 and 3.542 (P = 0.016) 24 h after bronchoscopy in the respective study groups.

CONCLUSION:

Low-dose dexmedetomidine (0.75 μg/kg single dose) appears to provide better patient comfort and equivalent safety profile when compared with midazolam.

A randomised study of comfort during bronchoscopy comparing conscious sedation and anaesthetist-controlled general anaesthesia, including the utility of bispectral index monitoring

Background

The difference in patient comfort with conscious sedation versus general anaesthesia for bronchoscopy has not been adequately assessed in a randomised trial. This study aimed to assess if patient comfort during bronchoscopy with conscious sedation is noninferior to general anaesthesia.

Methods

96 subjects were randomised to receive conscious sedation or general anaesthesia for bronchoscopy. The primary outcome was subject comfort. Secondary outcomes included willingness to undergo a repeat procedure if necessary and level of sedation assessed clinically and by bispectral index (BIS) monitoring.

Results

There was no significant difference between subject comfort scores (difference -0.01, 95% CI -0.63-0.61 on a 10-point scale; p=0.97) or willingness to undergo a repeat procedure (97.7% versus 91.8%, 95% CI -4.8-15.5%; p=0.37). Deeper levels of sedation in the general anaesthesia cohort was confirmed with both clinical and BIS monitoring. There was no significant difference in diagnostic accuracy (conscious sedation 93.9%, 95% CI 80.4-98.3% versus general anaesthesia 86.5%, 95% CI 72.0-94.1%; p=0.43). There were more complications (29.6%, 95% CI 18.2-44.2% versus 6.1%, 95% CI 2.1-16.5%; p<0.01) in the general anaesthesia group. There was no relationship between high BIS scores and subject discomfort. BIS levels <40 during a procedure were associated with increased complications.

Conclusion

Conscious sedation is not inferior to general anaesthesia in providing patient comfort during bronchoscopy, despite lighter sedation, and is associated with fewer complications and comparable diagnostic accuracy. BIS monitoring may have a role in preventing complications associated with deeper sedation.

Hypercapnia in COPD Patients Undergoing Endobronchial Ultrasound under Local Anaesthesia and Analgosedation: A Prospective Controlled Study Using Continuous Transcutaneous Capnometry

BACKGROUND

Flexible bronchoscopy (FB) in analgosedation causes alveolar hypoventilation and hypercapnia, the more so if patients suffer from COPD. Nonetheless, neither is capnometry part of standard monitoring nor is there evidence on how long patients should be monitored after sedation.

OBJECTIVES

We investigated the impact of COPD on hypercapnia during FB with endobronchial ultrasound (EBUS) in sedation and how the periprocedural monitoring should be adapted.

METHODS

Two cohorts of consecutive patients - with advanced and without COPD - with the indication for FB with EBUS-guided transbronchial needle aspiration in analgosedation received continuous transcutaneous capnometry (ptcCO2) before, during, and for 60 min after the sedation with midazolam and alfentanil.

MAIN RESULTS

Forty-six patients with advanced COPD and 44 without COPD were included. The mean examination time was 26 ± 9 min. Patients with advanced COPD had a higher peak ptcCO2 (53.7 ± 7.1 vs. 46.8 ± 4.8 mm Hg, p < 0.001) and mean ptcCO2 (49.5 ± 6.8 vs. 44.0 ± 4.4 mm Hg, p < 0.001). Thirty-six percent of all patients reached the maximum hypercapnia after FB in the recovery room (8 ± 11 min). Patients with COPD needed more time to recover to normocapnia (22 ± 24 vs. 7 ± 11 min, p < 0.001). They needed a nasopharyngeal tube more often (28 vs. 11%, p < 0.001). All patients recovered from hypercapnia within 60 min after FB. No intermittent ventilation manoeuvres were needed.

CONCLUSION

A relevant proportion of patients reached their peak-pCO2 after the end of intervention. We recommend using capnometry at least for patients with known COPD. Flexible EBUS in analgosedation can be safely performed in patients with advanced COPD. For patients with advanced COPD, a postprocedural observation time of 60 min was sufficient.

Flexible bronchoscopy in a tertiary healthcare facility: a review of indications and outcomes

Objectives

Flexible Fibreoptic bronchoscopy (FFB) is a major diagnostic and therapeutic tool employed largely in respiratory medicine but its use in our country has been quite limited. We performed a retrospective review of the indications, overall diagnostic yield and safety of FFB at the Korle-Bu Teaching Hospital (KBTH).

Study Design

Retrospective study.

Study Setting

Cardiothoracic Unit, Korle-Bu Teaching Hospital.

Study Participants

All bronchoscopy records from January 2017 - December 2018.

Interventions

Eight-five bronchoscopy reports generated over a 2-year period were reviewed. Using a data extraction form, patient's demographic details, indications for FFB, sedation given, specimen obtained and results of investigation, and complications encountered were recorded and entered into SPSS version 22. Descriptive analysis was performed and presented as means and percentages.

Results

Suspected lung cancer was the predominant indication for bronchoscopy requests (55.3%). Diagnostic yield of endobronchial biopsy was 86.7% increased to 93.3% when biopsy was combined with bronchial washing cytology. Bronchial washing geneXpert was positive in 20.8% of sputum negative cases, and 20.7% of patients with unresolved pneumonia and bronchiectasis had a positive microbial yield. Overall mild complications occurred in 5.9% of patients with no mortality.

Conclusion

Flexible bronchoscopy has a significantly high diagnostic yield, particularly in evaluating lung cancers and undiagnosed lung infections with minimal associated complications, hence increasing its availability in the country and widening the diagnostic scope at the cardiothoracic unit of the Korle-Bu Teaching Hospital.

Funding

None declared.

Conventional flexible bronchoscopy during the COVID pandemic: A consensus statement from the Indian Association for Bronchology

During the times of the ongoing COVID pandemic, aerosol-generating procedures such as bronchoscopy have the potential of transmission of severe acute respiratory syndrome coronavirus 2 to the healthcare workers. The decision to perform bronchoscopy during the COVID pandemic should be taken judiciously. Over the years, the indications for bronchoscopy in the clinical practice have expanded. Experts at the Indian Association for Bronchology perceived the need to develop a concise statement that would assist a bronchoscopist in performing bronchoscopy during the COVID pandemic safely. The current Indian Association for Bronchology Consensus Statement provides specific guidelines including triaging, indications, bronchoscopy area, use of personal protective equipment, patient preparation, sedation and anesthesia, patient monitoring, bronchoscopy technique, sample collection and handling, bronchoscope disinfection, and environmental disinfection concerning the coronavirus disease-2019 situation. The suggestions provided herewith should be adopted in addition to the national bronchoscopy guidelines that were published recently. This statement summarizes the essential aspects to be considered for the performance of bronchoscopy in COVID pandemic, to ensure safety for both for patients and healthcare personnel.

Oxygen desaturation during flexible bronchoscopy with propofol sedation is associated with sleep apnea: the PROSA-Study

BACKGROUND

Obstructive sleep apnea (OSA) is characterized by repetitive episodes of complete or partial obstruction of the upper airways during sleep. Conscious sedation for flexible bronchoscopy (FB) places patients in a sleep-like condition. We hypothesize that oxygen desaturation during flexible bronchoscopy may help to detect undiagnosed sleep apnea.

METHODS

Single-centre, investigator-initiated and driven study including consecutive patients undergoing FB for clinical indication. Patients completed the Epworth Sleepiness Scale (ESS), Lausanne NoSAS score, STOP-BANG questionnaire and the Berlin questionnaire and underwent polygraphy within 7 days of FB. FB was performed under conscious sedation with propofol. Oxygen desaturation during bronchoscopy was measured with continuous monitoring of peripheral oxygen saturation with ixTrend (ixellence GmbH, Germany).

RESULTS

145 patients were included in the study, 62% were male, and the average age was 65.8 ± 1.1 years. The vast majority of patients (n = 131, 90%) proved to fulfill OSA criteria based on polygraphy results: 52/131 patients (40%) had mild sleep apnea, 49/131 patients (37%) moderate sleep apnea and 30/131 patients (23%) severe sleep apnea. Patients with no oxygen desaturation had a significantly lower apnea-hypopnea index than patients with oxygen desaturation during bronchoscopy (AHI 11.94/h vs 21.02/h, p = 0.011). This association remained significant when adjusting for the duration of bronchoscopy and propofol dose (p = 0.023; 95% CI 1.382; 18.243) but did not hold when also adjusting for age and BMI.

CONCLUSION

The severity of sleep apnea was associated to oxygen desaturation during flexible bronchoscopy under conscious sedation. Patients with oxygen desaturation during bronchoscopy might be considered for sleep apnea screening.

TRIAL REGISTRATION

The Study was approved by the Ethics Committee northwest/central Switzerland, EKNZ (EK 16/13) and was carried out according to the Declaration of Helsinki and Good Clinical Practice guidelines. Due to its observational character, the study did not require registration at a clinical trial registry.

Sedation with fentanyl and midazolam without oropharyngeal anesthesia compared with sedation with pethidine and midazolam with oropharyngeal anesthesia in ultrathin bronchoscopy for peripheral lung lesions

BACKGROUND

In advanced lung cancer, precision medicine requires repeated biopsies via bronchoscopy at therapy change. Since bronchoscopies are often stressful for patients, sedation using both fentanyl and midazolam is recommended in Europe and America. In Japan, bronchoscopies are generally orally performed under midazolam and oropharyngeal anesthesia. Nasal intubation creates a physiological route to the trachea, causing less irritation to the pharynx than intubation via the oral cavity; however, the necessity of oropharyngeal anesthesia remains unclear. We aimed to compare the safety, patient discomfort, and diagnostic rates for oropharyngeal anesthesia and sedation with pethidine and midazolam (Group A) and sedation with midazolam and fentanyl without oropharyngeal anesthesia (Group B) for ultrathin bronchoscopy of peripheral pulmonary lesions (PPLs) via nasal intubation.

METHODS

We retrospectively reviewed 74 consecutive potential lung cancer patients who underwent ultrathin bronchoscopies at the Hakodate Goryoukaku Hospital between July 2019 and June 2020. We reviewed the following: diagnostic rates; cumulative doses of lidocaine, midazolam, and fentanyl; hemodynamic changes; procedural complications in both groups. Pharyngeal anesthesia in group A was administered by spraying 2% (w/v) lidocaine into the pharynx. The chi-squared test was used for statistical analyses.

RESULTS

There were no significant changes in hemodynamic parameters and complications. The mean level of discomfort for bronchoscopic examinations was significantly lower in Group B (2.39 vs. 1.64; P = 0.014), with no significant inter-group difference in the diagnostic yields for PPLs (63.0% vs. 71.4%; P = 0.46).

CONCLUSIONS

Our findings indicate the advantages of sedation with fentanyl and midazolam without oropharyngeal anesthesia for ultrathin bronchoscopy through nasal intubation.

Comparison of midazolam and low-dose dexmedetomidine in flexible bronchoscopy: A prospective, randomized, double-blinded study

BACKGROUND

Dexmedetomidine is a clinically useful drug for providing sedation, but concern regarding its cardiovascular side effect profile can limit its widespread use during routine diagnostic flexible bronchoscopy (FB).

MATERIALS AND METHODS

Patients between 18 and 65 years of age, who required diagnostic FB, were screened. Eligible patients were randomized to either receive 0.5 μg/kg intravenous dexmedetomidine over 10 min or intravenous midazolam 0.035 mg/kg over 1 min. If required, rescue medication (intravenous midazolam 0.5 mg bolus) was administered. The primary outcome measure was the composite score. Other parameters observed were numerical rating scale, hemodynamic variables, oxygen saturation, number of doses of rescue medication, visual analog scale score for cough, ease of bronchoscopy, Ramsay Sedation Score, and postprocedure patient response after 24 h of bronchoscopy.

RESULTS

A total of 54 patients were enrolled, 27 in each group. Total composite score (mean ± standard deviation) in dexmedetomidine and midazolam group at nasopharynx was 7.04 ± 2.19 and 6.59 ± 1.55 (P = 0.387), respectively. The corresponding values at the level of trachea were 9.22 ± 3.69 and 8.63 ± 2.13 (P = 0.475). In the dexmedetomidine group, patient response after 24 h of bronchoscopy showed the quality of sedation to be excellent in three patients, good in 10, fair in 11, and poor in 3 and discomfort to be nil in 14, mild 7, moderate in 3, and severe in 3. The corresponding values in the midazolam group for the quality of sedation were 0, 9, 18, 0 and for discomfort 10, 16, 1, 0. Other parameters did not reveal any statistically significant difference.

CONCLUSION

Dexmedetomidine at a dose of 0.5 μg/kg may provide clinically useful conscious sedation, comparable to midazolam.

MERS-CoV infection is associated with downregulation of genes encoding Th1 and Th2 cytokines/chemokines and elevated inflammatory innate immune response in the lower respiratory tract

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MERS-CoV infection downregulates Th1 and Th2 cytokines and chemokines.

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MERS-CoV infection provokes high levels of IL-1α, IL-1β and IL-8 (CXCL8).

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Inflammatory cytokines/chemokines correlate with MERS-CoV case fatality rate.

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Th1/Th2 downregulation may contribute to severe infection and evolution of ARDS.

MERS-CoV, a highly pathogenic virus in humans, is associated with high morbidity and case fatality. Inflammatory responses have a significant impact on MERS-CoV pathogenesis and disease outcome. However, CD4⁺ T-cell induced immune responses during acute MERS-CoV infection are barely detectable, with potent inhibition of effector T cells and downregulation of antigen presentation. The local pulmonary immune response, particularly the Th1 and Th2-related immune response during acute severe MERS-CoV infection is not fully understood. In this study, we offer the first insights into the pulmonary gene expression profile of Th1 and Th2-related cytokines/chemokines (Th1 & Th2 responses) during acute MERS-CoV infection using RT² Profiler PCR Arrays. We also quantified the expression level of primary inflammatory cytokines/chemokines. Our results showed a downregulation of Th2, inadequate (partial) Th1 immune response and high expression levels of inflammatory cytokines IL-1α and IL-1β and the neutrophil chemoattractant chemokine IL-8 (CXCL8) in the lower respiratory tract of MERS-CoV infected patients. Moreover, we identified a high viral load in all included patients. We also observed a correlation between inflammatory cytokines, Th1, and Th2 downregulation and the case fatality rate. Th1 and Th2 response downregulation, high expression of inflammatory cytokines, and high viral load may contribute to lung inflammation, severe infection, the evolution of pneumonia and ARDS, and a higher case fatality rate. Further study of the molecular mechanisms underlying the Th1 and Th2 regulatory pathways will be vital for active vaccine development and the identification of novel therapeutic strategies.

Guidelines for diagnostic flexible bronchoscopy in adults: Joint Indian Chest Society/National College of chest physicians (I)/Indian association for bronchology recommendations

Flexible bronchoscopy (FB) is commonly performed by respiratory physicians for diagnostic as well as therapeutic purposes. However, bronchoscopy practices vary widely across India and worldwide. The three major respiratory organizations of the country supported a national-level expert group that formulated a comprehensive guideline document for FB based on a detailed appraisal of available evidence. These guidelines are an attempt to provide the bronchoscopist with the most scientifically sound as well as practical approach of bronchoscopy. It involved framing appropriate questions, review and critical appraisal of the relevant literature and reaching a recommendation by the expert groups. The guidelines cover major areas in basic bronchoscopy including (but not limited to), indications for procedure, patient preparation, various sampling procedures, bronchoscopy in the ICU setting, equipment care, and training issues. The target audience is respiratory physicians working in India and well as other parts of the world. It is hoped that this document would serve as a complete reference guide for all pulmonary physicians performing or desiring to learn the technique of flexible bronchoscopy.

A Benefit Risk Review of Pediatric Use of Hydrocodone/Chlorpheniramine, a Prescription Opioid Antitussive Agent for the Treatment of Cough

Hydrocodone/chlorpheniramine is a prescription opioid licensed in the USA for the relief of cough and upper respiratory symptoms associated with allergy or cold in adults, previously contraindicated in children aged < 6 years. We present findings from a modern benefit risk review of hydrocodone/chlorpheniramine use as an antitussive agent in patients aged 6 to < 18 years. A cumulative search of the manufacturer’s pharmacovigilance database covering 1 January 1900–7 August 2017 identified all individual case safety reports (ICSRs) associated with product family name “hydrocodone/chlorpheniramine.” The search was inclusive of all MedDRA system organ classes, stratified by age (< 18 years). A comprehensive review of the scientific literature was conducted on safety and efficacy of opioids for pediatric treatment of cough. Three hundred and ninety-one ICSRs associated with hydrocodone/chlorpheniramine were identified; 35/391 ICSRs were in patients < 18 years of age; 18 were considered serious. Four fatalities were reported in patients 6 to < 18 years; two fatalities involved co-suspect medication azithromycin and two were poorly documented. Our literature search identified no robust efficacy data for hydrocodone/chlorpheniramine in the relief of cough and upper respiratory symptoms associated with allergy or cold in patients aged 6 to < 18 years. As we found no evidence of hydrocodone/chlorpheniramine efficacy in the pediatric population, we conclude that the benefit risk profile is unfavorable. This evidence contributed to the US Food and Drug Administration’s (FDA’s) recent decision that hydrocodone-containing cough and cold medications should no longer be indicated for treatment of cough in patients < 18 years, highlighting the value of proactive re-evaluation of the benefit risk profile of older established drugs.

Plain Language Summary

People often use medicines containing opioids to treat cough symptoms. The US Food and Drug Administration (FDA) recently decided that cough medicines containing opioids should not be used by children under 18 years old. Part of this decision was a review of the benefits and risks of using cough medicines that contain the opioid hydrocodone in children.

Why was this review carried out? Most cough medicines that doctors can prescribe were approved several decades ago. Since then, rules for the approval of medicines have become stricter. In this review, researchers looked at the safety of hydrocodone, and how well this opioid relieves cough symptoms in children. Up-to-date information and modern research methods were used.

The two key pieces of evidence found were:

We could not locate any clinical trials providing robust evidence for the use of hydrocodone for cough relief in children under 18 years of age. (Outside the scope of this review, a number of clinical trials of hydrocodone-containing cough medicines in adults aged 18 years and over have shown the medicine to be effective in these patients.)

Cough medicines containing opioids can cause harmful side effects in children such as breathing problems. In the research reported here, ten children died after taking a hydrocodone-containing cough medicine. Nine of these deaths were due to overdose.

This evidence was used to draw the following conclusions:

In children under 18 years of age, the risks of using hydrocodone for cough relief are greater than any benefits.

Older medicines should be reviewed regularly to look at their safety and how well they are working using up-to-date evidence.

Nebulization versus standard application for topical anaesthesia during flexible bronchoscopy under moderate sedation - a randomized controlled trial

Background

Endobronchial administration of lidocaine is commonly used for cough suppression during diagnostic bronchoscopy. Recently, nebulization of lidocaine during bronchoscopies under deep sedation with fiberoptic intubation using a distinct spray catheter has been shown to have several advantages over conventional lidocaine administration via syringe. However, there are no data about this approach in bronchoscopies performed under moderate sedation. Therefore, this study compared the tolerability and safety of nebulized lidocaine with conventional lidocaine administration via syringe in patients undergoing bronchoscopy with moderate sedation.

Methods

Patients requiring diagnostic bronchoscopy were randomly assigned to receive topical lidocaine either via syringe or via nebulizer. Endpoints were consumption of lidocaine and sedative drugs, as well as patient tolerance and safety.

Results

Sixty patients were included in the study (n = 30 in each group). Patients required lower doses of endobronchial lidocaine when given via nebulizer versus syringe (164.7 ± 20.8 mg vs. 250.4 ± 42.38 mg; p < 0.0001) whereas no differences in the dosage of sedative drugs were observed between the two groups (all p > 0.05). Patients in the nebulizer group had higher mean oxygen saturation (96.19 ± 2.45% vs. 94.21 ± 3.02%; p = 0.0072) and a lower complication rate (0.3 ± 0.79 vs. 1.17 ± 1.62 per procedure; p = 0.0121) compared with those in the syringe group.

Conclusions

Endobronchial lidocaine administration via nebulizer was well-tolerated during bronchoscopies under moderate sedation and was associated with reduced lidocaine consumption, a lower complication rate and better oxygenation compared with lidocaine administration via syringe.

Trial registration

The study was registered with clinicaltrials.gov (NCT02262442; 13^th October 2014).

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0926-5) contains supplementary material, which is available to authorized users.

Comparison of midazolam with fentanyl-midazolam combination during flexible bronchoscopy: A randomized, double-blind, placebo-controlled study

BACKGROUND:

Sedation during flexible bronchoscopy is desirable, but the drugs and the dosage protocols that are used vary.

OBJECTIVE:

To study and compare the effects of midazolam with fentanyl-midazolam combination during flexible bronchoscopy.

MATERIALS AND METHODS:

The study was conducted on 144 patients, from October 2013 to July 2015. They answered Hospital Anxiety and Depression Scale-Anxiety subscale and a prebronchoscopy questionnaire to assess their expectation toward flexible bronchoscopy. The patients were randomized into three groups: placebo, midazolam, and fentanyl-midazolam. Vitals signs including heart rate, respiratory rate, blood pressure, and oxygen saturation (SpO₂) were recorded. Furthermore, Ramsay Sedation Scale was assessed during the procedure. Primary outcome measure was the composite score of patient-reported tolerance and satisfaction (assessed after the procedure). Secondary outcome measures were composite score of physician-reported feasibility of the procedure, hemodynamic changes during bronchoscopy, and side effects.

RESULTS:

Patient-reported tolerance and satisfaction composite scores (median, interquartile range) for placebo, midazolam, and fentanyl-midazolam groups were 54 (52, 57), 59 (57, 61.5), 62 (58.5, 66), respectively; P < 0.001. Physician-reported feasibility composite scores (median, interquartile range) for the respective groups were 24.5 (20.5, 28), 25 (21, 27), 26 (25, 29); P = 0.004. There was no significant difference between the groups so far as mean heart rate (P = 0.305), mean systolic blood pressure (P = 0.532), mean diastolic blood pressure (P = 0.516), mean respiratory rate (P = 0.131), and mean SpO₂ (P = 0.968) were concerned.

CONCLUSION:

Conscious sedation with fentanyl and midazolam combination can result in better patient and operator satisfaction when compared with midazolam alone.

Pregabalin and dexmedetomidine conscious sedation for flexible bronchoscopy: a randomized double-blind controlled study

BACKGROUND

Conscious sedation is usually required during flexible bronchoscopy. Sedation should be achieved without respiratory depression or loss of consciousness. The present study was designed to evaluate the effect of pregabalin premedication on reducing the amount of sedatives and to show its advantages for patients undergoing flexible bronchoscopy with dexmedetomidine.

METHODS

Seventy patients undergoing elective flexible bronchoscopy were randomly divided into two groups of 35 patients each. All patients received premedication one hour before the procedure. PG group received 150 mg pregabalin and C group received placebo. All patients were sedated with dexmedetomidine infusion to achieve optimum sedation. During the procedure peripheral oxygen saturation, respiratory rate, hemodynamics, Ramsay sedation Score, cough score, and total amount of dexmedetomidine used were recoded. After the procedure patients' and pulmonologists' satisfaction were compared.

RESULTS

The total amount of dexmedetomidine used in PG was less compared to C group (P=0.01). Sedation score was higher in PG group at the time of theatre admission (P<0.001). Cough score was higher, but insignificant in group C (P=0.08). Patients' and pulmonologists' satisfaction scores were higher in group PG (P=0.007 and 0.001 respectively). The heart rate and mean arterial pressure were lower in the C group (P=0.02 and 0.03 respectively). Postoperative care unit stay was less in group PG with less analgesic requirements.

CONCLUSIONS

Conscious sedation facilitates flexible bronchoscopy. Premedication with pregabalin can reduce the amount of sedatives. Dexmedetomidine with pregabalin premedication has many advantages over dexmedetomidine alone.

The Effect of Dextromethorphan Premedication on Cough and Patient Tolerance During Flexible Bronchoscopy: A Randomized, Double-blind, Placebo-controlled Trial

BACKGROUND

Patients undergoing bronchoscopy can experience problems such as anxiety and cough, requiring various doses of sedatives and analgesics. The purposes of this study were to investigate the effect of premedication with dextromethorphan on patients' cough and anxiety, and the use of analgesics/sedatives during flexible bronchoscopy (FB).

METHODS

A randomized, double-blind, placebo-controlled, prospective study was performed to assess the effect of dextromethorphan premedication on patients who underwent diagnostic bronchoscopy. Seventy patients included in this study were randomly allocated into 2 groups: group A consisted of 35 patients who received dextromethorphan before FB; and group B consisted of 35 patients who received a placebo. A questionnaire was given to the patients and bronchoscopist about perception of cough, anxiety, and discomfort. The amount of sedative medication and lidocaine use during the procedure and the procedure time were recorded.

RESULTS

The group that was premedicated with dextromethorphan had lower complaint scores, significantly less coughing, significantly less stress assessed by the patient and the physician evaluation, shorter total procedure time, and fewer midazolam requirements during FB (P-value <0.05).

CONCLUSION

Considering its safety profile, dextromethorphan premedication is an effective approach to facilitate the performance of FB for the physician, and could improve patient comfort.

Anesthesia for interventional pulmonology procedures: a review of advanced diagnostic and therapeutic bronchoscopy

PURPOSE

Interventional pulmonology is a growing subspecialty of pulmonary medicine with flexible and rigid bronchoscopies increasingly used by interventional pulmonologists for advanced diagnostic and therapeutic purposes. This review discusses different technical aspects of anesthesia for interventional pulmonary procedures with an emphasis placed on pharmacologic combinations, airway management, ventilation techniques, and common complications.

SOURCE

Relevant medical literature was identified by searching the PubMed and Google Scholar databases for publications on different anesthesia topics applicable to interventional pulmonary procedures. Cited literature included case reports, original research articles, review articles, meta-analyses, guidelines, and official society statements.

PRINCIPAL FINDINGS

Interventional pulmonology is a rapidly growing area of medicine. Anesthesiologists need to be familiar with different considerations required for every procedure, particularly as airway access is a shared responsibility with pulmonologists. Depending on the individual case characteristics, a different selection of airway method, ventilation mode, and pharmacologic combination may be required. Most commonly, airways are managed with supraglottic devices or endotracheal tubes. Nevertheless, patients with central airway obstruction or tracheal stenosis may require rigid bronchoscopy and jet ventilation. Although anesthetic approaches may vary depending on factors such as the length, complexity, and acuity of the procedure, the majority of patients are anesthetized using a total intravenous anesthetic technique.

CONCLUSIONS

It is fundamental for the anesthesia provider to be updated on interventional pulmonology procedures in this rapidly growing area of medicine.

Bronchoscopic diagnosis of peripheral pulmonary lung cancer employing sedation with fentanyl and midazolam

BACKGROUND

Sedation with fentanyl and midazolam during bronchoscopic examination is commonly employed by pulmonary physicians in the USA and Europe. We assessed the efficacy of such sedation in the bronchoscopic diagnosis of peripheral lung cancer.

METHODS

We retrospectively evaluated data from 102 patients who underwent transbronchial biopsies (TBB) for diagnosis of peripheral lung cancer. Bronchoscopies with and without fentanyl were performed in 61 (group A) and 41 (group B) patients, respectively. Midazolam was administered to all patients. Medical records were retrieved, and between-group comparisons were made using unpaired Student's t-tests.

RESULTS

The mean fentanyl dose was 49.5 μg (range: 10-100 μg), and midazolam doses in groups A and B were 4.29mg (range: 1-14mg) and 5.54mg (range: 1-12mg), respectively. Diagnostic histological specimens were obtained from 75.4% and 65.8% of group A and B patients, respectively (P = 0.30). The diagnostic sensitivities for lung cancer, via at least one of TBB, cytological brushing, or bronchial washing, in groups A and B were 88.5% and 70.4%, respectively (P = 0.035). Moreover, lesion diagnostic sensitivities, via at least one of TBB, cytological brushing, and bronchial washing, in groups A and B were 98.1% and 68.0%, respectively (P = 0.01).

CONCLUSION

Fentanyl and midazolam sedation during bronchoscopy facilitated the diagnosis of peripheral pulmonary lung cancers.

Analogosedation during flexible bronchoscopy using a combination of midazolam, propofol and fentanyl - A retrospective analysis

BACKGROUND

According to current guidelines flexible bronchoscopy is usually performed under sedation. Previously it has been demonstrated that combined sedation with e. g. the combination of midazolam and propofol or an opioid might have several advantages over sedation with just one sedative drug. However, little is known about the efficacy and safety of combined sedation with midazolam, fentanyl and propofol (MFP) compared to sedation with midazolam and fentanyl (MF) or midazolam and propofol (MP).

METHODS

We carried out a retrospective analysis of bronchoscopies performed under triple (MFP) or double sedation (MF and MP) in an academic hospital. 1392 procedures were analyzed (MFP: n = 824; MF: n = 272; MP: n = 296). In particular, we compared the occurrence of complications and the dosage of administered sedative drugs between the groups.

RESULTS

The occurrence of adverse events (MFP vs. MF: odds ratio (OR) 1.116 [95% CI 0.7741 to 1.604]; MFP vs. MP: OR 0.8296 [95% CI 0.5939 to 1.16] and severe adverse events (MFP vs. MF: OR 1.581 [95% CI 0.5594 to 4.336]; MFP vs. MP: OR 3.47 [95% CI 0.908 to 15.15]; all p>0.05) was similar in all groups. The dosage of midazolam was lower in the MFP compared to the MF or MP group (MFP vs. MF: Cohen's d 0.075; MFP vs. MP: Cohen's d 0.225; all p<0.001). In addition patients in the MFP group received significantly less propofol compared to the MP group (Cohen's d 1.22; p<0.001).

CONCLUSIONS

In summary we were able to demonstrate that triple sedation can safely be administered during flexible bronchoscopy and is associated with a reduced dosage of midazolam and propofol.

Factors affecting patients' comfort during fiberoptic bronchoscopy and endobronchial ultrasound

Objective

This study investigated the factors that can affect the comfort of patients who underwent diagnostic fiberoptic bronchoscopy (FOB) and diagnostic endobronchial ultrasonography (EBUS) for the first time and the effect of the patients’ anxiety level on their comfort during the procedure.

Materials and methods

We recorded the demographics of the patients, the medications they used previously, the anesthesia applied during the procedure, the experience of the operator, the insertion technique of the bronchoscope, the types of the bronchoscopic interventions during the procedure, the duration of the procedure, and the anxiety levels of the patients before the session. Patients’ discomfort level before and after the procedure and anxiety levels before the procedure were evaluated using a visual analog scale (VAS), and willingness for repeating FOB and EBUS was assessed using a questionnaire.

Results

We found that longer examination time, higher anxiety level before the procedure, the nasal insertion of bronchoscope, and higher number of interventions are related to the increased discomfort during FOB and EBUS. Patients’ willingness for repeating FOB and EBUS increased as the level of discomfort decreased during the procedure.

Conclusion

The patient’s anxiety level should be determined using a questionnaire before the FOB and EBUS procedures, and the operator should adjust their procedure according to the patients’ anxiety level.

Complications and discomfort of bronchoscopy: a systematic review

Objective

To identify bronchoscopy-related complications and discomfort, meaningful complication rates, and predictors.

Method

We conducted a systematic literature search in PubMed on 8 February 2016, using a search strategy including the PICO model, on complications and discomfort related to bronchoscopy and related sampling techniques.

Results

The search yielded 1,707 hits, of which 45 publications were eligible for full review. Rates of mortality and severe complications were low. Other complications, for instance, hypoxaemia, bleeding, pneumothorax, and fever, were usually not related to patient characteristics or aspects of the procedure, and complication rates showed considerable ranges. Measures of patient discomfort differed considerably, and results were difficult to compare between different study populations.

Conclusion

More research on safety aspects of bronchoscopy is needed to conclude on complication rates and patient- and procedure-related predictors of complications and discomfort.

Lack of efficacy of pre bronchoscopy inhaled salbutamol on symptoms and lung functions in patients with pre-existing airway obstruction

BACKGROUND

Fiberoptic bronchoscopy (FOB) may exaggerate symptoms and lung functions in patients with pre-existing airway obstruction. Interventions which can alleviate or minimize this procedure-related bronchospasm, especially in this high-risk group are, therefore, required.

METHODS

A double-blinded randomized controlled trial was conducted to evaluate the efficacy of 400 μg of inhaled salbutamol on patients with spirometric evidence of airflow obstruction planned for FOB. Patient's dyspnea, procedure tolerability, and change in spirometry were assessed before and after the procedure.

RESULTS

A total of 50 patients were enrolled (78% males), with a mean (standard deviation) age of 49.8 (6.2) years. There was a significant fall in % predicted FEV1 within each group compared to their respective pre-bronchoscopy values. However, no significant difference in the % predicted or absolute FEV1 level was observed between the two groups. Similarly, although both groups experienced increased dyspnea immediately following FOB, this difference was not significant between the two groups either on the Borg or visual analog scale scales. Pre-FOB anxiety levels and the tolerability of the procedure as assessed by the bronchoscopist were similar in both groups.

CONCLUSION

FOB in patients with pre-existing airway obstruction aggravates cough and dyspnea, with a concomitant decline in FEV1 and FVC. The administration of pre-FOB inhaled salbutamol does not have any significant beneficial effect on procedure-related outcomes.

The role of cytochrome P450 pharmacogenomics in chronic non-cancer pain patients

INTRODUCTION

Pharmacogenomics is the field that studies an individualized treatment approach for patients' medication regimen that can impact drug safety, productivity, and personalized health care. Pharmacogenomics characterizes the genetic differences in metabolic pathways which can affect a patient's individual responses to drug treatments. Areas covered: The various responses to pharmacological agents are mainly determined by the different types of genetic variants of the CYP450. CYP2D6 polymorphism is well known for its variation in the metabolism of drugs from many therapeutic arenas, including some analgesic drugs such as codeine, hydromorphone, oxycodone and tramadol. Allele combinations determine the phenotypic expression, characterized as either: extensive metabolizer, intermediate metabolizer, ultra-rapid metabolizer and poor metabolizer. Expert opinion: The Human Genome Project (HGP) revolutionized the future of medicine and the way health care providers approach individualized patient treatment, and chronic pain management is one of those areas. The key findings in the literature appear to be related to the CYP2D6 expression and its high polymorphism influencing the metabolism of opioid medications, and the impact of that on the patient's therapeutic outcome thus exemplifying the importance of genetic testing for CYP2D6 in the process of physician therapeutic decision making.

Safety and discomfort during bronchoscopy performed under sedation with fentanyl and midazolam: a prospective study

OBJECTIVE

Although sedation with fentanyl and midazolam during bronchoscopic examination is widely accepted in the USA and Europe, it is not routine practice in Japan. The objective of the present study was to evaluate sedation with fentanyl and midazolam during bronchoscopy.

METHODS

Thirty-seven patients were enrolled prospectively between November 2014 and July 2015 at Okayama University Hospital. Fentanyl (20 μg) was administered to the patients just before the examination, and fentanyl (10 μg) and midazolam (1 mg) were added as needed during the procedure. A questionnaire was administered 2 hours after the examination. In the questionnaire, patient satisfaction was scored using a visual analog scale as follows: great (1 point), good (2 points), normal (3 points), uncomfortable (4 points) and very uncomfortable (5 points). An additional question ('Do you remember the bronchoscopic examination?') was also used. Predefined matters for investigation (e.g. blood pressure, heart rate, oxygen saturation and complications) were recorded.

RESULTS

The enrolled patients included 13 males and 24 females; the median age was 67 (range: 31-87) years. The patients received a median dose of fentanyl of 45.4 μg (range: 30-100 μg) and midazolam of 2.56 mg (range: 1-10 mg). Twenty-six patients (70.2%) agreed to undergo a second bronchoscopic examination, and the average levels of discomfort and re-examination were 2.02 points for each. Only 37.8% of the patients remembered the bronchoscopic examination. No severe complications were reported.

CONCLUSIONS

Sedation with fentanyl and midazolam during bronchoscopic examination should be recommended for use in Japan.

Monitored anesthesia care in and outside the operating room

Monitored anesthesia care (MAC) is an anesthesia technique combining local anesthesia with parenteral drugs for sedation and analgesia. The use of MAC is increasing for a variety of diagnostic and therapeutic procedures in and outside of the operating room due to the rapid postoperative recovery with the use of relatively small amounts of sedatives and analgesics compared to general anesthesia. The purposes of MAC are providing patients with safe sedation, comfort, pain control and satisfaction. Preoperative evaluation for patients with MAC is similar to those of general or regional anesthesia in that patients should be comprehensively assessed. Additionally, patient cooperation with comprehension of the procedure is an essential component during MAC. In addition to local anesthesia by operators or anesthesiologists, systemic sedatives and analgesics are administered to provide patients with comfort during procedures performed with MAC. The discretion and judgment of an experienced anesthesiologist are required for the safety and efficacy profiles because the airway of the patients is not secured. The infusion of sedatives and analgesics should be individualized during MAC. Many procedures in and outside of the operating room, including eye surgery, otolaryngologic surgery, cardiovascular procedures, pain procedures, and endoscopy are performed with MAC to increase patient and operator satisfaction.

Target-controlled versus fractionated propofol sedation in flexible bronchoscopy: A randomized noninferiority trial

BACKGROUND AND OBJECTIVE

Fractionated propofol administration (FPA) in flexible bronchoscopy (FB) may lead to oversedation and an increased risk of adverse events, because a stable plasma concentration of propofol is not maintainable. The purpose of this randomized noninferiority trial was to evaluate whether target-controlled infusion (TCI) of propofol is noninferior to FPA in terms of safety in FB.

METHODS

Coprimary outcomes were the mean lowest arterial oxygen saturation (SpO₂ ) during FB and the number of propofol dose adjustments in relation to procedure duration. Secondary outcomes were the number of occasions with SpO₂  < 90% and/or oxygen desaturations of >4% from baseline, number of occasions with systolic blood pressure < 90 mm Hg, cough frequency, cumulative propofol dose, recovery time, maximum transcutaneous CO₂ , mean SpO₂ and O₂ delivery during FB.

RESULTS

Seventy-seven patients were included. TCI was noninferior to FPA in terms of mean (standard deviation) lowest SpO₂ during the procedure (88.3% (5.4%) vs 86.9% (7.3%)) and required fewer dose adjustments (0.04/min vs 0.28/min, P < 0.001) but a higher cumulative propofol dose (264 vs 194 mg, P = 0.003). All other secondary outcomes were comparable between the groups.

CONCLUSION

We suggest that TCI of propofol is a favourable sedation technique for FB with equal safety issues and fewer dose adjustments compared with FPA.

COPD Exacerbations Are Associated With Proinflammatory Degradation of Hyaluronic Acid

BACKGROUND

COPD is characterized by chronic airway inflammation and remodeling, with serious modifications of the extracellular matrix (ECM). Hyaluronic acid (HA) is an abundant ECM molecule in the lung with various biologic functions that depend on its molecular weight (MW). High-MW HA exhibits antiinflammatory and immunosuppressive effects, whereas low-MW HA is proinflammatory. In this study, we investigated whether acute exacerbations of COPD (AECOPDs), which affect patient quality of life and survival, are associated with altered HA turnover in BAL.

METHODS

We used BAL from patients with stable COPD (n = 53) or during AECOPD (n = 44) matched for demographics and clinical characteristics and BAL from control subjects (n = 15). HA, HA synthase-1 (HAS-1), and hyaluronidase (HYAL) values were determined by enzyme-linked immunosorbent assay, and HYAL activity was determined by HA zymography. The MW of HA was analyzed by agarose electrophoresis.

RESULTS

Levels of HA, HAS-1, and HYAL were significantly increased in BAL of patients with stable COPD and during exacerbations compared with control subjects. HYAL activity was significantly increased in BAL of patients with AECOPD, resulting in an increase of low-MW HA during exacerbations. In patients with AECOPD, we also observed a significant negative correlation of HA and HYAL levels with FEV1 % predicted but not with diffusing capacity of lung for carbon monoxide % predicted, indicating that increased HA degradation may be more associated with airway obstruction than with emphysema.

CONCLUSIONS

AECOPDs are associated with increased HYAL activity in BAL and subsequent degradation of HA, which may contribute to airway inflammation and subsequent lung function decline during exacerbations.

Topical Nasal Anesthesia in Flexible Bronchoscopy--A Cross-Over Comparison between Two Devices

Introduction

Topical airway anesthesia is known to improve tolerance and patient satisfaction during flexible bronchoscopy (FB). Lidocaine is commonly used, delivered as an atomized spray. The current study assesses safety and patient satisfaction for nasal anesthesia of a new atomization device during outpatient bronchoscopy in lung transplant recipients.

Methods

Using a prospective, non-blinded, cross-over design, patients enrolled between 01-10-2014 and 24-11-2014 received 2% lidocaine using the standard reusable nasal atomizer (CRNA). Those enrolled between 25-11-2014 and 30-01-2015, received a disposable intranasal mucosal atomization device (DIMAD). After each procedure, the treating physician, their assistant and the patient independently rated side-effects and satisfaction, basing their responses on visual analogue scales (VAS). At their next scheduled bronchoscopy during the study period, patients then received the alternative atomizer. Written consent was obtained prior to the first bronchoscopy, and the study approved by the institutional ethics committee.

Results

Of the 252 patients enrolled between 01-10-2014 and 30-01-2015, 80 (32%) received both atomizers. Physicians reported better efficacy (p = 0.001) and fewer side effects (p< = 0.001) for DIMAD in patients exposed to both procedures. Among patients with one visit, physicians and their assistants reported improved efficacy (p = 0.018, p = 0.002) and fewer side effects (p< = 0.001, p = 0.029) for the disposable atomizer, whereas patients reported no difference in efficacy or side effects (p = 0.72 and p = 0.20). No severe adverse events were noted. The cost of the reusable device was 4.08€ per procedure, compared to 3.70€ for the disposable device.

Discussion

Topical nasal anesthesia via a disposable intranasal mucosal atomization device (DIMAD) offers comparable safety and patient comfort, compared to conventional reusable nasal atomizers (CRNA) in lung transplant recipients. Procedural costs were reduced by 0.34€ per procedure.

Trial Registration

clinicaltrials.gov NCT02237651

A comparison of propofol-midazolam and midazolam alone for sedation in endobronchial ultrasound-guided transbronchial needle aspiration: a retrospective cohort study

OBJECTIVES

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a new, minimally invasive, bronchoscopic technique used in the evaluation of inthrathoracic lymph nodes.Use of sedation drugs before the procedure differs among centres. There is no standardization about sedation before EBUS-TBNA.We used a policy decision to shift from use of propofol with midazolam vs midazolam alone in a large tertiary hospital to evaluate the diagnostic yield and safety of EBUS-TBNA procedure.

METHODS

Files of all the patients who were performed EBUS-TBNA between the dates of September 2010 and May 2014 were surveyed. All the EBUS-TBNA cases were performed under sedation of propofol and midazolam with an accompanying anesthesiologist in the beginning, however, sedation is applied with midazolam without an accompanying anesthesiologist after April 2013 due to changes in sedation policy. The diagnostic yield and complication rates were compared by chi-squared analysis between two groups.

RESULTS

The files of 340 EBUS-TBNA performed patients were evaluated. Of the patients 274 eligible patients were analysed. 152 patients who fulfilled the inclusion criteria were analysed in propofol-midazolam (P) sedated group and 122 patients were analysed in midazolam (M) group. There is no statistically significant difference between two different sedated groups in terms of age and gender. Diagnostic value was detected as 77.6% in P group and 85.7% in M group and the difference was not statistically significant. No difference between complication rates of both groups was observed.

CONCLUSION

Both sedation-types for performing EBUS-TBNA showed similar diagnostic value and complication rates in our study. Propofol with midazolam application requires with an accompanying anaesthesiologist, therefore, it increases cost. EBUS-TBNA procedures had been performed in safe with no decrease in diagnostic yield under moderate sedation.

A Randomized Trial of 1% vs 2% Lignocaine by the Spray-as-You-Go Technique for Topical Anesthesia During Flexible Bronchoscopy

BACKGROUND

The optimal concentration of lignocaine to be used during flexible bronchoscopy (FB) remains unknown. This randomized controlled trial compared the efficacy and safety of 1% and 2% lignocaine solution for topical anesthesia during FB.

METHODS

Consecutive patients were randomized to receive either 1% or 2% lignocaine solution through the bronchoscope by the "spray-as-you-go" technique. The primary outcome of the study was the assessment of cough by the operator and the patient using the visual analog scale (VAS) and pain assessment using the faces pain rating scale. The secondary outcomes included total lignocaine dose, oxygenation status, adverse reactions related to lignocaine, and others.

RESULTS

Five hundred patients were randomized (median age, 51 years; 71% men) 1:1 to either group. The median operator VAS score for cough was significantly higher (25 vs 21, P = .015) in the 1% group; however, the patient VAS score was not significantly different (32 vs 27, P = .065). The pain rating was similar between the two groups. The median cumulative dose of lignocaine was significantly higher in the 2% group (397 mg vs 312 mg, P = .0001; 7.1 mg/kg vs 5.7 mg/kg, P = .0001). About 28% of patients in the 2% group exceeded the maximum recommended dose (> 8.2 mg/kg) of lignocaine. No adverse event related to lignocaine overdose was seen in either group.

CONCLUSIONS

One percent lignocaine was found to be as effective as 2% solution for topical anesthesia during FB, albeit at a significantly lower dose as the latter. Thus, 1% lignocaine should be the preferred concentration for topical anesthesia during FB.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01955824; URL: www.clinicaltrials.gov.

Safety and Efficacy of the Moderate Sedation During Flexible Bronchoscopic Procedure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Moderate sedatives have been increasingly used to improve patient comfort during flexible bronchoscopy (FB). However, routine use of moderate sedation during FB is controversial because its efficacy and safety are not well established. This study aims to evaluate the efficacy and safety of moderate sedation during FB. A search was made of Medline, EMBASE, and the Cochrane Library to May 2014. Randomized controlled trials (RCTs) and quasi-RCTs were included. The main analysis was designed to examine the efficacy of moderate sedation during FB in sedation than no-sedation. The willingness to repeat FB was significantly more in sedation than no-sedation (odds ratio [OR] 2.30; 95% confidence interval [CI] 1.11-4.73; P = 0.02; I2 = 22.5). The duration of FB was shorter in sedation group than no-sedation group (standardized mean difference [SMD] -0.21; 95% CI -0.38 to -0.03; P = 0.02; I2 = 78.3%). Event of hypoxia was not significantly different between sedation and no-sedation groups (OR 0.86; 95% CI 0.42-1.73; P = 0.67; I2 = 0%). The SpO2 during procedure was not different between sedation and no-sedation groups (SMD -0.14; 95% CI -0.37 to 0.08; P = 0.21; I2 = 49.9%). However, in subgroup analysis without supplemental oxygen, the SpO2 was significantly lower in sedation than no-sedation group (SMD -0.45; 95% CI -0.78 to -0.11; P = 0.01; I2 = 0.0%). According to this meta-analysis, moderate sedation in FB would be useful in patients who will require repeated bronchoscopies as well as safe in respiratory depression. To our knowledge, although the various sedative drugs are already used in the real field, this analysis was the first attempt to quantify objective results. We anticipate more definite and studies designed to elucidate standardized outcomes for moderate sedation in FB.

Acute exacerbations of COPD are associated with significant activation of matrix metalloproteinase 9 irrespectively of airway obstruction, emphysema and infection

Background

Acute exacerbations of chronic obstructive pulmonary disease (AE-COPD) are associated with accelerated aggravation of clinical symptoms and deterioration of pulmonary function. The mechanisms by which exacerbations may contribute to airway remodeling and declined lung function are poorly understood. In this study, we investigated if AE-COPD are associated with differential expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in bronchoalveolar lavage (BAL).

Methods

COPD patients undergoing diagnostic bronchoscopy, with either stable disease (n = 53) or AE-COPD (n = 44), matched for their demographics and lung function parameters were included in this study. Protein levels of MMP-2,–9,–12 and of TIMP-1 and -2 in BAL were measured by ELISA. Enzymatic activity of MMP-2 and -9 was assessed by gelatin zymography.

Results

We observed that MMP-9, TIMP-1 and TIMP-2 were significantly increased in BAL during AE-COPD. Furthermore, there was a significant negative correlation of MMP-9, TIMP-1 and TIMP-2 with FEV1% predicted and a significant positive correlation of TIMP-1 and TIMP-2 with RV% predicted in AE-COPD. None of MMPs and TIMPs correlated with DLCO% predicted, indicating that they are associated with airway remodeling leading to obstruction rather than emphysema. In AE-COPD the gelatinolytic activity of MMP-2 was increased and furthermore, MMP-9 activation was significantly up-regulated irrespective of lung function, bacterial or viral infections and smoking.

Conclusions

The results of this study indicate that during AE-COPD increased expression of TIMP-1, TIMP-2, and MMP-9 and activation of MMP-9 may be persistent aggravating factors associated with airway remodeling and obstruction, suggesting a pathway connecting frequent exacerbations to lung function decline.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-015-0240-4) contains supplementary material, which is available to authorized users.