Effect of Nebulizer Designs on Aerosol Delivery During Non-Invasive Mechanical Ventilation: A Modeling Study of In Vitro Data

Wound dehiscence in enhanced recovery after open radical cystectomy: A meta-analysis

A meta-analysis study to assess the outcome of enhanced recovery (ER) after radical cystectomy (RC) on wound dehiscence was performed. A comprehensive literature examination till January 2023 was implemented and 1457 linked studies were appraised. The picked studies contained 772 open RC subjects in the picked studies' baseline, 436 of them were enhanced recovery after RC, and 336 were open RC. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to calculate the consequence of enhanced recovery after RC on wound dehiscence after open RC by the dichotomous styles and a fixed or random model. The ER after RC caused significantly lower wound dehiscence (OR, 0.51; 95% CI, 0.30-0.89, P = .02) with low heterogeneity (I2  = 46%) compared with open RC. The ER after RC caused significantly lower wound dehiscence compared with open RC. Thorough precaution should be taken when commerce with the consequences because a limited number of studies were found and selected for this meta-analysis.

Effect of possible risk factors for pharyngocutaneous fistula after total laryngectomy of laryngeal carcinomas and surgical wound infection: A meta-analysis

A meta-analysis study to assess the effect of possible risk factors for pharyngocutaneous fistula (PCF) after total laryngectomy of laryngeal carcinoma. A comprehensive literature examination till January 2023 was implemented and 1794 linked studies were appraised. The picked studies contained 3140 subjects with total laryngectomy of laryngeal carcinomas in the picked studies' baseline, 760 of them were PCF, and 2380 were no PCF. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to calculate the consequence of possible risk factors for PCF after total laryngectomy of laryngeal carcinomas and surgical wound infection after total laryngectomy of laryngeal carcinoma by the dichotomous and continuous styles and a fixed or random model. The PCF had a significantly higher surgical wound infection (OR, 6.34; 95% CI, 1.89-21.27, P = .003) compared with the no PCF in total laryngectomy of laryngeal carcinomas. The smoking (OR, 1.73; 95% CI, 1.15-2.61, P = .008), and preoperative radiation (OR, 1.90; 95% CI, 1.37-2.65, P < .001) had significantly higher PCF as a risk factor in total laryngectomy of laryngeal carcinomas. The preoperative radiation had a significantly lower spontaneous PCF closure (OR, 0.33; 95% CI, 0.14-0.79, P = .01) compared with the no preoperative radiation in total laryngectomy of laryngeal carcinomas. However, the neck dissection (OR, 1.34; 95% CI, 0.75-2.38, P = .32), and alcohol intake (OR, 1.95; 95% CI, 0.76-5.05, P = .17), had no significant effect on PCF in total laryngectomy of the PCF had a significantly higher surgical wound infection, and preoperative radiation had a significantly lower spontaneous PCF closure in total laryngectomy of laryngeal carcinomas. Smoking and preoperative radiation were shown to be risk factors for PCF, however, neck dissection and alcohol intake were not shown to be risk factors for PCF in total laryngectomy of laryngeal carcinomas. Although precautions should be taken when commerce with the consequences because some of the picked studies for this meta-analysis was with low sample sizes.

Effect of ultrasound-supported wound debridement in subjects with diabetic foot ulcers: A meta-analysis

A meta-analysis study to assess the effect of ultrasound-supported wound debridement (USSD) in subjects with diabetic foot ulcer (DFU). A comprehensive literature examination till January 2023 was implemented and 1873 linked studies were appraised. The picked studies contained 577 subjects with DFUs in the studies' baseline, 282 of them were using USSD, 204 were using standard care, and 91 were using a placebo. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to calculate the consequence of USSD in subjects with DFUs by the dichotomous styles and a fixed or random effect model. The USSD applied to DFU caused a significantly higher wound healing rate compared with the standard care (OR, 3.08; 95% CI, 1.94-4.88, P < .001) with no heterogeneity (I2  = 0%) and the placebo (OR, 7.61; 95% CI, 3.11-18.63, P = .02) with no heterogeneity (I2  = 0%). The USSD applied to DFUs caused a significantly higher wound healing rate compared with the standard care and the placebo. Though precautions should be taken when commerce with the consequences as all of the picked studies for this meta-analysis was with low sample sizes.

Effect of honey dressing in the management of diabetic foot ulcers: A meta-analysis

A meta-analysis study to assess the effect of honey dressing (HD) in the management of diabetic foot ulcer (DFU). A comprehensive literature examination till January 2023 was implemented and 1794 linked studies were appraised. The picked studies contained 882 subjects with DFUs were in the picked studies' baseline, 424 of them were using HD, and 458 were using a control. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to calculate the consequence of HD in the management of DFUs after DFU by the dichotomous and continuous styles and a fixed or random model. The HD applied to DFUs caused a significantly higher wound healing rate (OR, 2.06; 95% CI, 1.45-2.93, P < .001) and lower wound healing time (MD, -10.42; 95% CI, -16.27- -4.58, P < .001) compared with the control. The HD applied to DFUs caused a significantly higher wound healing rate and lower wound healing time compared with the control. Although precautions should be taken when commerce with the consequences since most of the picked studies for this meta-analysis was with low sample sizes.

Aerosol therapy in adult critically ill patients: a consensus statement regarding aerosol administration strategies during various modes of respiratory support

BACKGROUND

Clinical practice of aerosol delivery in conjunction with respiratory support devices for critically ill adult patients remains a topic of controversy due to the complexity of the clinical scenarios and limited clinical evidence.

OBJECTIVES

To reach a consensus for guiding the clinical practice of aerosol delivery in patients receiving respiratory support (invasive and noninvasive) and identifying areas for future research.

METHODS

A modified Delphi method was adopted to achieve a consensus on technical aspects of aerosol delivery for adult critically ill patients receiving various forms of respiratory support, including mechanical ventilation, noninvasive ventilation, and high-flow nasal cannula. A thorough search and review of the literature were conducted, and 17 international participants with considerable research involvement and publications on aerosol therapy, comprised a multi-professional panel that evaluated the evidence, reviewed, revised, and voted on recommendations to establish this consensus.

RESULTS

We present a comprehensive document with 20 statements, reviewing the evidence, efficacy, and safety of delivering inhaled agents to adults needing respiratory support, and providing guidance for healthcare workers. Most recommendations were based on in-vitro or experimental studies (low-level evidence), emphasizing the need for randomized clinical trials. The panel reached a consensus after 3 rounds anonymous questionnaires and 2 online meetings.

CONCLUSIONS

We offer a multinational expert consensus that provides guidance on the optimal aerosol delivery techniques for patients receiving respiratory support in various real-world clinical scenarios.

Effect of minimally invasive surgery and laparotomy on wound infection and postoperative and intraoperative complications in the management of cervical cancer: A meta-analysis

We performed a meta-analysis to evaluate the effect of minimally invasive surgery and laparotomy on wound infection and postoperative and intraoperative complications in the management of cervical cancer. A systematic literature search up to July 2022 was performed and 10 231 subjects with cervical cancer at the baseline of the studies; 4307 of them were using the minimally invasive surgery, and 5924 were using laparotomy. Odds ratio (OR) with 95% confidence intervals (CIs) were calculated to assess the effect of minimally invasive surgery and laparotomy on wound infection and postoperative and intraoperative complications in the management of cervical cancer using the dichotomous methods with a random or fixed-effect model. The minimally invasive surgery had significantly lower wound infection (OR, 0.20; 95% CI, 0.13-0.30, P < .001), and postoperative complications (OR, 0.48; 95% CI, 0.37-0.64, P < .001) in subjects with cervical cancer compared laparotomy. However, minimally invasive surgery compared with laparotomy in subjects with cervical cancer had no significant difference in intraoperative complications (OR, 1.04; 95% CI, 0.80-1.36, P = 0.76). The minimally invasive surgery had significantly lower wound infection, and postoperative complications however, had no significant difference in intraoperative complications in subjects with cervical cancer compared with laparotomy. The analysis of outcomes should be with caution because of the low sample size of 22 out of 41 studies in the meta-analysis and a low number of studies in certain comparisons.

Effect of powdered vancomycin on stopping surgical site wound infections in neurosurgery: A meta-analysis

We performed a meta-analysis to evaluate the effect of powdered vancomycin on stopping surgical site wound infections in neurosurgery. A systematic literature search up to July 2022 was performed and 24 137 subjects with neurosurgery at the baseline of the studies; 10 496 of them were using the powdered vancomycin, and 13 641 were not using the powdered vancomycin as a control. Odds ratio (OR) with 95% confidence intervals (CIs) were calculated to assess the effect of powdered vancomycin on stopping surgical site wound infections in neurosurgery using dichotomous methods with a random or fixed-effect model. The powdered vancomycin had significantly lower surgical site wound infections after spinal surgery (OR, 0.53; 95% CI, 0.41-0.70, P < .001), deep surgical site wound infections after spinal surgery (OR, 0.45; 95% CI, 0.35-0.57, P < .001), superficial surgical site wound infections after spinal surgery (OR, 0.60; 95% CI, 0.43-0.83, P = .002), and surgical site wound infections after cranial surgery (OR, 0.37; 95% CI, 0.22-0.61, P < .001) compared to control in subjects with neurosurgery. The powdered vancomycin had significantly lower surgical site wound infections after spinal surgery, deep surgical site wound infections after spinal surgery, superficial surgical site wound infections after spinal surgery, and surgical site wound infections after cranial surgery compared to control in subjects with neurosurgery. The analysis of outcomes should be done with caution even though the low number of studies with low sample size, 3 out of the 42 studies, in the meta-analysis, and a low number of studies in certain comparisons.

The outcome of prolonged postoperative antibiotics on wound healing in orthognathic surgery: A meta-analysis

We conducted a meta-analysis to assess the outcome of prolonged postoperative antibiotics (PA) on wound healing in orthognathic surgery (OS). A systematic literature search up to January 2023 was performed and 1021 related studies were evaluated. The chosen studies comprised 1057 OS subjects who participated in the selected studies' baseline, 446 of them used short-term PA, and 611 used long-term PA. Odds ratio (OR) with 95% confidence intervals (CIs) were calculated to assess the effect of prolonged PA on wound infection after OS by the dichotomous methods with a random or fixed effect model. The short-term PA resulted in significantly higher wound infection (OR, 4.27; 95% CI, 2.97-6.14, P < 0.001) with low heterogeneity (I²  = 27%) compared to the long-term PA in OS. The short-term PA resulted in significantly higher wound infection compared to the long-term PA in OS. Though care should be taken when dealing with the results since a large number of the selected studies had <100 subjects as a sample size.

A path forward in the development of new aerosol drug delivery devices for pediatrics

Inhaled medications are widely accepted as being the optimal route for treating pediatric respiratory diseases, a leading cause of hospitalization and death. Despite jet nebulizers being the preferred inhalation device for neonates and infants, current devices face performance issues with most of the drug never reaching the target lung location. Previous work has aimed to improve pulmonary drug deposition, yet nebulizer efficiency remains low. The development of an inhalant therapy that is efficacious and safe for pediatrics depends on a well-designed delivery system and formulation. To accomplish this, the field needs to rethink the current practice of basing pediatric treatments on adult studies. The rapidly evolving pediatric patient (i.e. neonates to eighteen) needs to be considered because they are different from adults with respect to airway anatomy, breathing patterns, and adherence. Previous research approaches to improve deposition efficiency have been limited due to the complexity of combining physics, which drives aerosol transport and deposition, and biology, especially within the area of pediatrics. To address these critical knowledge gaps, we need a better understanding of how patient age and disease state affect deposition of aerosolized drugs. The complexity of the multiscale respiratory system makes scientific investigation very challenging. The authors have simplified the complex problem into five components with these three areas as ones to address first: how the aerosol is (i) generated in a medical device, (ii) delivered to the patient, and (iii) deposited inside the lung. In this review, we discuss the technological advances and innovations made from experiments, simulations, and predictive models in each of these areas. In addition, we discuss the impact on patient treatment efficacy and recommend a clinical direction, with a focus on pediatrics. In each area, a series of research questions are posed and steps for future research to improve efficacy in aerosol drug delivery are outlined.

27-gauge microincision vitrectomy surgery compared with 25-gauge microincision vitrectomy surgery on wound closure and need for wound suture and other postoperative parameters in the treatment of vitreoretinal disease: A meta-analysis

We performed a meta-analysis to evaluate the effect of 27-gauge microincision vitrectomy surgery compared with 25-gauge microincision vitrectomy surgery on wound closure and the need for wound suture and other postoperative parameters in the treatment of vitreoretinal disease. A systematic literature search up to June 2022 was performed and 1264 subjects with the vitreoretinal disease at the baseline of the studies; 562 of them were using the 27-gauge microincision vitrectomy surgery, and 722 were using 25-gauge microincision vitrectomy surgery. Odds ratio (OR), and mean difference (MD) with 95% confidence intervals (CIs) were calculated to assess the effect of 27-gauge microincision vitrectomy surgery compared with 25-gauge microincision vitrectomy surgery on wound closure and the need for wound suture and other postoperative parameters in the treatment of vitreoretinal disease using the dichotomous, and contentious methods with a random or fixed-effect model. The 27-gauge microincision vitrectomy surgery subjects had a significantly lower intraoperative and postoperative wound complication (OR, 6.66; 95% CI, 0.46-0.95, P = .02), and wound suture number (OR, 0.38; 95% CI, 0.20-0.71, P = .002), and best corrected visual acuity (MD, -0.03; 95% CI, -0.05 to -0.001, P = .02) compared with 25-gauge microincision vitrectomy surgery in subjects with vitreoretinal disease. However, 27-gauge microincision vitrectomy surgery subjects had no significant difference in the wound closure time (MD, -8.45; 95% CI, -23.44 to 6.55, P = .27), operation time (MD, 0.85; 95% CI, -1.17 to 2.86, P = .41), intraocular pressure at postoperative day 1 (MD, 0.42; 95% CI, -1.45-2.28, P = .66), primary anatomical success rate (OR, 0.83; 95% CI, 0.42-1.63, P = .58), and central macular thickness (MD, 1.81; 95% CI, -21.76 to 25.37, P = .88) compared to 25-gauge microincision vitrectomy surgery in subjects with vitreoretinal disease. The 27-gauge microincision vitrectomy surgery subjects had a significantly lower intraoperative and postoperative wound complication, wound suture number, and best corrected visual acuity, and no significant difference in the wound closure time, operation time, intraocular pressure at postoperative day 1, primary anatomical success rate, and central macular thickness compared to 25-gauge microincision vitrectomy surgery in subjects with vitreoretinal disease. The analysis of outcomes should be with caution because of the low sample size of 12 out of 15 studies in the meta-analysis and a low number of studies in certain comparisons.

A meta-analysis examined the effect of topical nursing application of antimicrobial as a prophylaxis for the stoppage of surgical wound infection in colorectal surgery

To assess the impact of topical antimicrobial (TA) as a prophylaxis for the stoppage of surgical wound infection (SWI) in colorectal surgery (CS), we lead a meta-analysis. 9160 participants with CS were enrolled in the chosen studies; 4719 of them used TA, while 4441 served as controls. To assess the effectiveness of TA application in lowering SWIs following CS, odds ratios (OR) with 95% confidence intervals (CIs) were computed with a dichotomous technique with a fixed- or random-effect model. Significantly lower SWIs post CS for TA as whole (OR, 0.50; 95% CI, 0.38-0.64; P < .001), gentamicin collagen sponge and beads (OR, 0.52; 95% CI, 0.32-0.86; P = .01), triclosan impregnated fascial suture (OR, 0.57; 95% CI, 0.38-0.84; P = .005), antibiotic powder, ointment, lavage, or injection for the abdominal wound (OR, 0.35; 95% CI, 0.21-0.59; P < .001), and ionised silver dressing on the closed abdominal wound (OR, 0.45; 95% CI, 0.27-0.77; P = .003) compared to control. Significantly lower SWIs post CS for TA as a whole, gentamicin collagen sponge and beads, triclosan impregnated fascial sutures, antibiotic powder, ointment, lavage, or injection for the abdominal wound, and ionised silver dressing on the closed abdominal wound compared with control. The low sample size of 8 out of the 39 included studies in this meta-analysis calls for precaution when analysing the outcomes.

A meta-analysis examined the effect of topical vancomycin application in decreasing sternal wound infections post cardiac surgery

To assess the impact of topical vancomycin (TV) application in decreasing sternal wound infections (SWIs) post cardiac surgery (CS), we lead a meta-analysis. Twenty-three thousand seven hundred and forty five participants had CS at the outset of the investigations, according to a thorough evaluation of the literature done up to November 2022; 8730 of them used TV, while 15 015 were controls. To assess the effectiveness of TV application in lowering SWIs following CS, odds ratios (OR) with 95% confidence intervals (CIs) were computed with dichotomous technique with a fixed- or random-effect model. The TV had significantly lower SWIs post CS (OR, 0.34; 95% CI, 0.20-0.57; P < .001), and deep SWIs post CS (OR, 0.26; 95% CI, 0.11-0.65; P = .004) compared with control as shown in Figures 2 and 3. Yet, there was no significant difference found amongst TV and control in superficial SWIs post CS (OR, 0.30; 95% CI, 0.07-1.30; P = .011). The TV had significantly lower SWIs, and deep SWIs post CS, and no significant difference was found in superficial SWIs post CS compared with control. The low number of included studies in this meta-analysis for superficial SWIs calls for precaution when analysing the outcomes.

Effect of cefuroxime intracameral injection antibiotic prophylactic on postoperative endophthalmitis wound post‐cataract: A meta‐analysis

To assess the impact of cefuroxime injection of intracameral prophylaxis antibiotic on after endophthalmitis operative wound following surgery of cataract, we conducted a meta-analysis. A thorough review of the literature up to July 2022 revealed that there were 1 167 197 participants with surgery of cataract at the start of the research; 1 004 425 of these subjects received an injection of intracameral of cefuroxime, while 162 772 did not get an antibiotic as a control. Using dichotomous approaches and a random or fixed-effect model, odds ratios (OR) with 95% confidence intervals (CIs) were estimated to evaluate the impact of cefuroxime injection of intracameral prophylaxis antibiotic on after endophthalmitis operative wound following surgery of cataract. When comparing no antibiotic in participants who had surgery of cataract, the cefuroxime injection of intracameral significantly reduced the after endophthalmitis operative wound (OR, 0.14; 95% CI, 0.07-0.29, P = 0.001) with high heterogeneity (I2 = 95%). When comparing participants who received no antibiotic after surgery of cataract, the after endophthalmitis operative wound from the cefuroxime injection of intracameral was considerably lower. Although none of the 22 studies encompassed in the meta-analysis had a study with a small sample size, it is nevertheless advisable to proceed with caution when analysing the results.

Oncological results in women with wound complications following mastectomy and immediate breast reconstruction: A meta‐analysis

We performed a meta-analysis to evaluate the oncological results in women with wound complications following mastectomy and immediate breast reconstruction. A systematic literature search up to August 2022 was performed and 1618 subjects with mastectomy and immediate breast reconstruction at the baseline of the studies; 443 of them were with wound complications, and 1175 were with no wound complications as a control. Odds ratio (OR) and mean difference (MD) with 95% confidence intervals (CIs) were calculated to assess the oncological results in women with wound complications following mastectomy and immediate breast reconstruction using dichotomous or contentious methods with a random or fixed-effect model. The wound complications had a significantly longer length of time to adjuvant therapy (MD, 9.44; 95% CI, 4.07-14.82, P < .001) compared with no wound complications in subjects with mastectomy and immediate breast reconstruction. However, no significant difference was found between wound complications and no wound complications in subjects with mastectomy and immediate breast reconstruction in breast cancer recurrence (OR, 1.96; 95% CI, 0.95-4.06, P = .07), death rates (OR, 1.95; 95% CI, 0.89-4.27, P = .09), and kind of immediate breast reconstruction (OR, 1.01; 95% CI, 0.53-1.92, P = .98). The wound complications had a significantly longer length of time to adjuvant, however, no significant difference was found in breast cancer recurrence, death rates, and kind of immediate breast reconstruction. The analysis of outcomes should be done with caution even though no low sample size was found in the meta-analysis but a low number of studies was found in certain comparisons.

Effect of wound protectors in reducing the incidence of surgical site wound infection in lower gastrointestinal surgery: A meta-analysis

We performed a meta-analysis to evaluate the effect of wound protectors in reducing the incidence of surgical site wound infection in lower gastrointestinal surgery. A systematic literature search up to June 2022 was performed and 6026 subjects with lower gastrointestinal surgery at the baseline of the studies; 3090 of them were using the wound protector, and 2936 were using no wound protector. Odds ratio (OR) with 95% confidence intervals (CIs) were calculated to assess the effect of wound protectors in reducing the incidence of surgical site wound infection in lower gastrointestinal surgery using the dichotomous methods with a random or fixed-effect model. The surgical site wound infection was significantly lower with single-ring wound protectors (OR, 0.53; 95% CI, 0.39-0.83, P = .004), and dual-ring wound protectors (OR, 0.44; 95% CI, 0.35-0.56, P < .001) in subjects with lower gastrointestinal surgery compared with no wound protector. The surgical site wound infection was significantly lower with single-ring wound protectors, and dual-ring wound protectors in subjects with lower gastrointestinal surgery compared with no wound protector. The analysis of outcomes should be with caution because of the low sample size of 5 out of 28 studies in the meta-analysis and a low number of studies in certain comparisons.

Impact of different nebulisers' connections on aerosol therapy

BACKGROUND

Aerosol therapy has the advantage of a higher safety because of the local deposition of inhaled medication to the lung; however, the main drawback is the low and variable amount of delivered drug to patients. Hence, this study aimed to investigate the effect of different accessory connections on aerosol delivery from different nebulisers.

METHOD

This study consisted of 3 main models: in vitro, in vivo and ex vivo models. In vitro model, 6 nebulisers (3 Jet (Dolphin (2030 2001), Philips (SideStream) and Tylenol (TL009002)) and 3 vibrating mesh nebulisers (VMNs) (Aerogen Pro, Solo, an Nivo)) were charged with 5 mg/2 mL salbutamol and connected to 2 different connections (T-piece and Circulaire II Hybrid) with an inhalation filter attached to a breathing simulator. Inhaled amounts of drug (inhalation filter) and that remained inside nebuliser were measured. Concerning ex vivo and in vivo models, 24 subjects were involved in the study and they received 5 mg/2 mL salbutamol from 1 Jet nebuliser and 1 VMNs using both connections. Two urine samples were collected post 30 minutes and pooled 24 hours urine collection. For the ex vivo model, inhaled amounts of salbutamol were collected on filters placed between the subjects and the nebuliser.

RESULTS

Inhaled amounts of salbutamol expressed by the amount of drug detected on inhalation filters (for both in vitro and ex vivo) were significantly higher from both Jet and VMNs connected to the Circulaire II Hybrid connection than that released from nebulisers connected to T-piece. VMNs delivered a higher amount compared with jet nebulisers. The amount released from jet nebulizers were variables, unlike VMNs. Regarding in vivo results, amounts of drug detected in 30 minutes urine samples were consistent with in vitro and ex vivo models reflecting higher and significant amounts of drug delivered to the patient's lung for Circulaire II Hybrid connection compared with T-piece regarding both nebulisers.

CONCLUSION

Using a valved chamber with jet and VMNs significantly improved the inhaled amount of the emitted aerosol. VMNs were more effective than jet nebulisers with both connections.

Delivered dose with jet and mesh nebulisers during spontaneous breathing, noninvasive ventilation and mechanical ventilation using adult lung models

What is the delivered dose with jet and mesh nebulisers during spontaneous breathing (SB), noninvasive ventilation (NIV), and mechanical ventilation (MV) using an adult lung model with exhaled humidity (EH)? The delivery of salbutamol sulfate (2.5 mg per 3 mL) with jet (Mistymax10) and mesh nebulisers (Aerogen Solo) was compared during SB, NIV, and MV using breathing parameters (tidal volume 450 mL, respiratory rate 20 breaths per min, inspiratory:expiratory ratio 1:3) with three lung models simulating exhaled humidity. A manikin was attached to a sinusoidal pump via a filter at the bronchi to simulate an adult with SB. A ventilator (V60) was attached via a facemask to a manikin with a filter at the bronchi connected to a test lung to simulate an adult receiving NIV. A ventilator-dependent adult was simulated through a ventilator (Servo-i) operated with a heated humidifier (Fisher & Paykel) attached to an endotracheal tube (ETT) with a heated-wire circuit. The ETT was inserted into a filter (Respirgard II). A heated humidifier was placed between the filter and test lung to simulate exhaled humidity (35±2°C, 100% relative humidity). Nebulisers were placed at the Y-piece of the inspiratory limb during MV and positioned between the facemask and the leak-port during NIV. A mouthpiece was used during SB. The delivered dose was collected in an absolute filter that was attached to the bronchi of the mannequin during each aerosol treatment and measured with spectrophotometry. Drug delivery during MV was significantly greater than during NIV and SB with a mesh nebuliser (p=0.0001) but not with a jet nebuliser (p=0.384). Delivery efficiency of the mesh nebuliser was greater than the jet nebuliser during MV (p=0.0001), NIV (p=0.0001), and SB (p=0.0001). Aerosol deposition obtained with a mesh nebuliser was greater and differed between MV, NIV, and SB, while deposition was low with a jet nebuliser and similar between the modes of ventilation tested.

Effect of functional principle, delivery technique, and connection used on aerosol delivery from different nebulizers: An in-vitro study

OBJECTIVE

Nebulizers can be divided according to their functional principle into jet, ultrasonic and vibrating mesh nebulizers with intermittent or continuous aerosol delivery and may be used with many different adapters and connections and all can influence their efficiency. The aim of the present work was to evaluate the effect functional principle, delivery technique, and connection used on aerosol delivered from four different nebulizers.

METHODS

Four nebulizers were used in the study; three of them were jet nebulizers (JNs; AeroEclipse, NebuTech, En ful Kit) and one of them was Aerogen Solo vibrating mesh nebulizers (VMN). AeroEclipse and NebuTech are intermittent output nebulizers, while the rest are continuous output nebulizers. Aerogen Solo was used with either a standard T-piece or Aerogen Ultra holding chamber, and En ful Kit was used with a standard T-piece or Circulaire II holding chamber. 2 ml of salbutamol was nebulized to determine the total emitted dose (TED) and aerodynamic droplet characteristics of the emitted aerosol from the 6 different sets (4 nebulizers with T-piece and 2 holding chambers).

RESULTS

The mean ± SD TED from VMN was significantly higher than all the JNs (p < 0.05). Aerogen Ultra with VMN did not show a significant effect on TED compare to T-piece, but it significantly increased (p < 0.05) fine particle dose (FPD; 3091.5 ± 189.4 μg) and fine particle fraction (FPF; 72.7 ± 3.6%). However, the Circulaire II with En ful Kit had significantly higher TED, FPD, and FPF compared to T-piece (p < 0.05). Intermittent JNs (AeroEclipse and NebuTech) had significantly higher TED (p < 0.05) compared to the continuous JNs (En ful Kit) with no significant effect on the other parameters studied. AeroEclipse had the highest MMAD and Aerogen Solo Ultra has the lowest in MMAD.

CONCLUSIONS

The functional principle, delivery technique, and connection used had a significant effect on aerosol delivered from nebulizers. VMNs are significantly better than JNs. Intermittent delivery has significantly better TED than continuous delivery. Holding chamber with both VMNs and JNs improved aerosol delivery compared to standard T-piece.

Lung deposition and systemic bioavailability of dose delivered to smoker compared with non-smoker COPD subjects

INTRODUCTION

Inhaled drugs are the most commonly used class of medications for COPD subjects. No studies have been performed to assess the influence of smoking on lung deposition of aerosolized medication, especially for the exacerbated COPD subject. The present study aimed to assess the influence of smoking on the lung deposition of the aerosol delivered to exacerbated COPD subjects.

METHODS

Twenty-four exacerbated COPD subjects using automatic continuous positive airway pressure (Auto-CPAP), 12 smokers (six females) and 12 non-smokers (six females) were recruited in the study. The subjects participated in the study received four salbutamol study doses; 1200 µg (12 puffs 100 µg/puff) of salbutamol emitted from pMDI canister connected to AeroChamber MV spacer; 1200 µg of salbutamol emitted from pMDI canister connected to Combihaler spacer; 1 mL of salbutamol respirable solution (5000 µg/mL) nebulized by Aerogen Solo connected to its T-piece; and 1 mL of salbutamol respirable solution nebulized by Aerogen Solo connected to Combihaler spacer with 2 puffs salbutamol MDI (200 µg salbutamol) before nebulisation. The subjects were randomised to receive the four selected dose-adaptor combination in a sealed envelope design on days 1, 3, 5 and 7. A washout period of 24 hours was provided between each salbutamol dosing. Auto-CPAP was adjusted at non-invasive ventilation mode with the integrated heated humidifier, as a source of humidity. Urine samples were provided by subjects, 30 minutes and cumulatively 24 hours post inhalation, as an index of the relative and systemic bioavailability, respectively, and aliquots were retained for salbutamol analysis using solid-phase extraction and high-performance liquid chromatography (HPLC). On day 2 of the study, a collecting filter was placed between the aerosol generator and the subject's mask so that the subjects would not inhale the salbutamol delivered. The same study doses and/or adapters were delivered to each subject, with filters changed with each dose-adapter combination. Salbutamol entrained on the filter was desorbed to be analysed by the HPLC.

RESULTS

Significantly higher lung deposition (30 minutes urinary salbutamol) was detected with the non-smoker compared with smokers (P < .05). Significantly higher systemic bioavailability (pooled 24-hour urinary salbutamol) for smokers compared with non-smokers was found with Aerogen Solo connected to its T-piece and CombiHaler spacer with pMDI (P < .05) only. Significantly higher amount desorbed from the ex-vivo filter were found from pMDI with both spacers in non-smokers (P < .05) compared with the smokers.

CONCLUSION

The study demonstrated that smoking reduced the lung deposition of inhaled salbutamol delivered by nebulizer or pMDI. However, the smoking effect on cytochrome p450 was observed to increase systemic absorption of the ingested portion of the inhaled dose. The lower lung deposition and possible higher systemic absorption should be taken into consideration while prescribing inhaled medication to COPD smokers especially exacerbated patients that need ventilation. Further studies are needed.

Aerosol Delivery to a Critically Ill Patient: A Big Issue Easily Solved by Developing Guidelines

Nowadays, therapeutic aerosols are commonly delivered to mechanically ventilated patients by nebulizers and pressurized metered dose inhaler attached to an adapter or a spacer. Studies with asthmatics and chronic obstructive pulmonary disease patients have confirmed that aerosol delivery during mechanical ventilation is feasible. They have also reported that the inhaled drugs administered during mechanical ventilation provide greater and faster clinical outcomes than when delivering during spontaneous unassisted breathing. Researchers studied factors that would affect aerosol delivery during mechanical ventilation. Even with the tremendous amount of publications in this area, there have still been no recommendations or guidelines released to help respiratory therapists in their decision as to when to deliver aerosol to ventilated patients. Mostly, respiratory therapists read the literature and decide accordingly what to do and which device to use for their patients. This puts the patients at risk of receiving a sub-therapeutic or toxic dose of the inhaled aerosol. Some studies raise an alarm of physician decision upon reading any released publication related to aerosol delivery in mechanical ventilation without a trusted recommendation and guidelines. This increases the need for the development of recommendations and guidelines, by a trusted board or society, for aerosol delivery to such critically ill patients. To summarize, inhaled drugs administered to critically ill patients is of benefit compared to taking the patient off the ventilator and delivering during spontaneous unassisted breathing. However, dependable guidelines are needed to optimize aerosol delivery.

The Impact of Adding a Training Device to Familiar Counselling on Inhalation Technique and Pulmonary Function of Asthmatics

INTRODUCTION

We have investigated the effect of adding a pressurized metered dose inhaler (pMDI) training device to verbal counselling on pulmonary function and inhalation technique.

METHODS

A total of 304 adult asthmatic subjects (> 18 years old) were enrolled in a 3-month study of assessment and education. They were divided into an investigation group (Trainhaler plus Flo-Tone and verbal counselling, n = 261, mean age 49.2 years) and a control group (verbal counselling only, n = 43, mean age 48.7 years). Pulmonary function and inhalation technique were evaluated, mistakes noted, and the correct technique advised at three consecutive monthly visits. Visits also included verbal pMDI counselling (both groups) and training device coaching (investigation group).

RESULTS

By visit 2, the mean number of technique errors decreased significantly (p < 0.05) in both groups (investigation group p < 0.001). The investigation group demonstrated a marked decrease in the frequency of the critical error of maintaining a slow inhalation rate until the lungs are full-a technique difficult to learn via verbal counselling alone. The improvement in pulmonary function was significant from the second clinic visit in the investigation group (p < 0.05) and from the third visit in both groups (p < 0.001).

CONCLUSIONS

Use of a training device combined with verbal counselling improved inhalation technique. An earlier, significant improvement was also noted in pulmonary function.

Modeling and optimization of nebulizers' performance in non-invasive ventilation using different fill volumes: Comparative study between vibrating mesh and jet nebulizers

BACKGROUNDS

Substituting nebulisers by another, especially in non-invasive ventilation (NIV), involves many process-variables, e.g. nebulizer-type and fill-volume of respirable-dose, which might affect patient optimum-therapy. The aim of the present work was to use neural-networks and genetic-algorithms to develop performance-models for two different nebulizers.

METHODS

In-vitro, ex-vivo and in-vivo models were developed using input-variables including nebulizer-type [jet nebulizer (JN) and vibrating mesh nebulizer (VMN)] fill-volumes of respirable dose placed in the nebulization chamber with an output-variable e.g. average amount reaching NIV patient. Produced models were tested and validated to ensure effective predictivity and validity in further optimization of nebulization process.

RESULTS

Data-mining produced models showed excellent training, testing and validation correlation-coefficients. VMN showed high nebulization efficacy than JN. JN was affected more by increasing the fill-volume. The optimization process and contour-lines obtained for in-vivo model showed increase in pulmonary-bioavailability and systemic-absorption with VMN and 2 mL fill-volumes.

CONCLUSIONS

Modeling of aerosol-delivery by JN and VMN using different fill-volumes in NIV circuit was successful in demonstrating the effect of different variable on dose-delivery to NIV patient. Artificial neural networks model showed that VMN increased pulmonary-bioavailability and systemic-absorption compared to JN. VMN was less affected by fill-volume change compared to JN which should be diluted to increase delivery.

Lung deposition and systemic bioavailability of different aerosol devices with and without humidification in mechanically ventilated patients

BACKGROUND

During mechanical ventilation medical aerosol delivery has been reported to be upto two fold greater with dry inhaled gas than with heated humidity. Urine levels at 0.5 h post dose (URSAL0.5%) has been confirmed as an index of lung deposition and 24 h (URSAL24%) as index of systemic absorption. Our aim was to determine the effect of humidification and aerosol device type on drug delivery to ventilated patients using urine levels.

METHODS

In a randomized crossover design, 36 (18female) mechanically ventilated patients were assigned to one of three groups. Groups 1 and 2 received 5000 μg salbutamol using vibrating mesh (VM) and jet nebulizers (JN), respectively, while group 3 received 1600 μg (16 puffs) of salbutamol via metered dose inhaler with AeroChamber Vent (MDI-AV). All devices were placed in the inspiratory limb of ventilator downstream from the humidifier. Each subject received aerosol with and without humidity at >24 h intervals with >12 h washout periods between salbutamol doses. Patients voided urine 15 min before each study dose and urine samples were collected at 0.5 h post dosing and pooled for the next 24 h.

RESULTS

The MDI-AV and VM resulted in a higher percentage of urinary salbutamol levels compared to the JN (p < 0.05). Urine levels were similar between humidity and dry conditions.

CONCLUSIONS

Our findings suggest that in-vitro reports overestimate the impact of dry vs. heated humidified conditions on the delivery of aerosol during invasive mechanical ventilation.