Pulmonary Procedures in the COVID-19 Era

Purpose of Review

The purpose of this review is to discuss the impact of the COVID-19 pandemic on pulmonary procedures, including new guidelines, restrictions, techniques, and overall effect on patient care.

Recent Findings

SARS-CoV-2 predominately impacts the pulmonary system and can result in a severe lower respiratory tract infection. Early guidelines based largely on data from the SARS epidemic recommended significant restrictions on procedure volume out of concern for healthcare worker safety. Newer data suggests relative safety in performing airway and pleural procedures as long as appropriate precautions are followed and new techniques are utilized. The introduction of effective vaccines and more reliable testing has led to a re-expansion of elective procedures.

Summary

Many guidelines and expert statements exist for the management and practice of pulmonary procedures during the COVID-19 pandemic. A flexible and individualized approach may be necessary as our understanding of COVID-19 continues to evolve.

The Epidemiology of Adult Tracheostomy in the United States 2002-2017: A Serial Cross-Sectional Study

Describe the longitudinal national epidemiology of tracheostomies performed in acute care hospitals and describe the annual rate of tracheostomy performed for patients with respiratory failure with invasive mechanical ventilation.

DESIGN

Serial cross-sectional study.

SETTING

The 2002-2014 and 2016-2017 Healthcare Utilization Project's National Inpatient Sample datasets.

PATIENTS

Discharges greater than or equal to 18 years old, excluding those with head and neck cancer or transferred from another hospital. We used diagnostic and procedure codes from the International Classification of Diseases, 9th and 10th revisions to define cases of respiratory failure, invasive mechanical ventilation, and tracheostomy.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were an estimated 80,612 tracheostomies performed in 2002, a peak of 89,545 tracheostomies in 2008, and a nadir of 58,840 tracheostomies in 2017. The annual occurrence rate was 37.5 (95% CI, 34.7-40.4) tracheostomies per 100,000 U.S. adults in 2002, with a peak of 39.7 (95% CI, 36.5-42.9) in 2003, and with a nadir of 28.4 (95% CI, 27.2-29.6) in 2017. Specifically, among the subgroup of hospital discharges with respiratory failure with invasive mechanical ventilation, an annual average of 9.6% received tracheostomy in the hospital. This changed over the study period from 10.4% in 2002, with a peak of 10.9% in 2004, and with a nadir of 7.4% in 2017. Among respiratory failure with invasive mechanical ventilation discharges with tracheostomy, the annual proportion of patients 50-59 and 60-69 years old increased, whereas patients from 70 to 79 and greater than or equal to 80 years old decreased. The mean hospital length of stay decreased, and in-hospital mortality decreased, whereas discharge to intermediate care facilities increased.

CONCLUSIONS

Over the study period, there were decreases in the annual total case volume and adult occurrence rate of tracheostomy as well as decreases in the rate of tracheostomy among the subgroup with respiratory failure with invasive mechanical ventilation. There is some evidence of changing patterns of patient selection for in-hospital tracheostomy among those with respiratory failure with invasive mechanical ventilation with decreasing proportions of patients with advanced age.

Variable Learning Curve of Basic Rigid Bronchoscopy in Trainees

BACKGROUND

Despite increased use of rigid bronchoscopy (RB) for therapeutic indications and recommendations from professional societies to use performance-based competency, an assessment tool has not been utilized to measure the competency of trainees to perform RB in clinical settings.

OBJECTIVES

The aim of the study was to evaluate a previously developed assessment tool - Rigid Bronchoscopy Tool for Assessment of Skills and Competence (RIGID-TASC) - for determining the RB learning curve of interventional pulmonary (IP) trainees in the clinical setting and explore the variability of learning curve of trainees.

METHODS

IP fellows at 4 institutions were enrolled. After preclinical simulation training, all RBs performed in patients were scored by faculty using RIGID-TASC until competency threshold was achieved. Competency threshold was defined as unassisted RB intubation and navigation through the central airways on 3 consecutive patients at the first attempt with a minimum score of 89. A regression-based model was devised to construct and compare the learning curves.

RESULTS

Twelve IP fellows performed 178 RBs. Trainees reached the competency threshold between 5 and 24 RBs, with a median of 15 RBs (95% CI, 6-21). There were differences among trainees in learning curve parameters including starting point, slope, and inflection point, as demonstrated by the curve-fitting model. Subtasks that required the highest number of procedures (median = 10) to gain competency included ability to intubate at the first attempt and intubation time of <60 s.

CONCLUSIONS

Trainees acquire RB skills at a variable pace, and RIGID-TASC can be used to assess learning curve of IP trainees in clinical settings.

Pleuroscopy for diagnosis and therapy for pleural effusions

Pleuroscopy, also known as medical thoracoscopy, is a minimally invasive procedure to inspect and perform a biopsy of the pleural space as well as to perform therapeutic interventions. It differs from conventional video-assisted thoracic surgery in that it may be performed under moderate sedation in the endoscopy suite without the need for intubation or single-lung ventilation. The diagnostic accuracy of this procedure approaches 100% in malignant and tuberculous pleural effusions. Complication rates are low (2%-5%) and are typically minor (subcutaneous emphysema, bleeding, infection), with mortality rates <0.1%. Therapeutic interventions, such as chemical pleurodesis, may be performed during pleuroscopy for recurrent, symptomatic malignant pleural effusions, with success rates approaching 90%. In trained hands, pleuroscopy is a safe and well-tolerated procedure with high diagnostic accuracy and therapeutic efficacy.

Alcohol abuse enhances pulmonary edema in acute respiratory distress syndrome

BACKGROUND

Pulmonary edema is a cardinal feature of the life-threatening condition known as acute respiratory distress syndrome (ARDS). Patients with chronic alcohol abuse are known to be at increased risk of developing and dying from ARDS. Based upon preclinical data, we hypothesized that a history of chronic alcohol abuse in ARDS patients is associated with greater quantities and slower resolution of pulmonary edema compared with ARDS patients without a history of alcohol abuse.

METHODS

A PiCCO transpulmonary thermodilution catheter was inserted into 35 patients within 72 hours of meeting American European Consensus Criteria definition of ARDS. Pulmonary edema was quantified as extravascular lung water (EVLW) and measured for up to 7 days in 13 patients with a history of chronic alcohol abuse and 22 patients without a history of chronic alcohol abuse.

RESULTS

Mean EVLW was higher in patients with a history of chronic alcohol abuse (16.6 vs. 10.5 ml/kg, p < 0.0001). Patients with alcohol abuse had significantly greater EVLW over the duration of the study (RM-ANOVA p = 0.003). There was a trend towards slower resolution of EVLW in patients with a history of alcohol abuse (a decrease of 0.5 ml/kg vs. 2.4 ml/kg, p = 0.17) over the study period. A history of alcohol abuse conferred a greater than 3-fold increased risk of elevated EVLW [OR 3.16, (1.26 to 7.93)] using multivariate logistic regression analysis.

CONCLUSIONS

In patients who develop ARDS, alcohol abuse is associated with greater levels EVLW and a trend towards slower resolution of EVLW. Combined with mechanistic and preclinical evidence linking chronic alcohol consumption and ARDS, targeted therapies should be developed for these patients.

Effects of metoclopramide and bethanechol on delayed gastric emptying present in gastroesophageal reflux patients

Gastric emptying has been reported to be delayed in a significant percentage of patients with gastroesophageal reflux. The rationale for the use of metoclopramide and bethanechol in gastroesophageal reflux has been based on their ability to stimulate lower esophageal sphincter pressure and enhance acid clearance mechanisms. In this study, we investigated the comparative efficacies of metoclopramide and bethanchol in improving the rate of gastric emptying in gastroesophageal reflux patients in whom delayed emptying was present. Gastric emptying studies used an isotope-labeled mixed solid-liquid meal. Thirteen reflux patients with delayed gastric emptying received metoclopramide, 10 mg intramuscularly, and subcutaneous bethanechol, 0.07 mg/kg, in a randomized single-blind fashion. Eleven additional reflux patients with delayed gastric emptying received oral metoclopramide, 10 mg, in an open-labeled fashion. After parenteral metoclopramide, gastric emptying was significantly (p less than 0.05) faster compared with both the initial basal day and the bethanechol treatment day. Compared with the normal gastric emptying rate established in 26 control subjects, metoclopramide accelerated gastric emptying into the normal range. Bethanechol did not increase gastric emptying. Metoclopramide orally also significantly improved gastric emptying. Our study indicates that metoclopramide, both parenterally and orally, increased the rate of gastric emptying in those reflux esophagitis patients in whom it was delayed, while bethanechol did not improve the degree of gastric retention in the same patients. Our results extend the rationale for the therapeutic efficacy of metoclopramide in gastroesophageal reflux disease.

Interaction of levodopa and metoclopramide on gastric emptying

Dopamine is postulated as an inhibitory neurotransmitter in the alimentary tract. The purposes of this study were to determine the effect of levodopa on the rate of gastric emptying in man and to investigate the interaction of levodopa and metoclopramide (a putative dopamine antagonist) on gastric emptying. On separate days, 7 normal male subjects received oral levodopa, 1,000 mg, and placebo in a randomized double-blind fashion 20 min before taking a mixed solid-liquid test meal labeled with 99mtechnetium(Tc)-diethylenetriamine pentaacetic acid. Gastric emptying was measured over 90 min by a gamma camera technique. At 90 min, the mean percent isotope remaining in the stomach after placebo, 54.7 +/- 5.0%, was less than after levodopa, 85.1 +/- 4.9% (p less than 0.01). Four of these normal subjects were studied further, and received levodopa, 1,000 mg, and metoclopramide, 10 mg, by intramuscular injection, 20 min before the same labeled test meal. In these 4 subjects, at 90 min, mean percent isotope remaining in the stomach after the combination of levodopa and metoclopramide, 48.5 +/- 2.2%, was less than after levodopa alone, 83.3 +/- 7.0% (p less than 0.05), and in the same range as mean percent after placebo, 47.3 +/- 3.6%. It is concluded that (1) levodopa inhibited gastric emptying of isotope in a mixed solid-liquid meal in normal subjects; (2) metoclopramide antagonized this effect returning gastric emptying to normal; and (3) the data suggest the possibility that dopaminergic receptors have an inhibitory effect on gastric emptying of the human stomach.

Resting host and tumor perfusion as determinants of tumor vascular responses to norepinephrine

Blood flow determinations and arteriograms were obtained in rat (Walker carcinoma) and rabbit (V2 carcinoma) liver tumors at rest and after norepinephrine administration. Resting tumor blood flow exceeded resting hepatic flow in both models, and both tumors responded with vasoconstriction and reduced blood flow. In tumors and the surrounding normal host tissue, the greater the perfusion prior to drug administration, the greater is the response (decrease in perfusion) to the vasoconstrictor. Although tumor perfusion decreased after vasoconstrictor, post-norepinephrine angiograms revealed an improved diagnostic image because of the enlarged but unresponsive tumor feeder vessels, persistent tumor blush, and simultaneous vasoconstriction in the normal liver. In these models, improved tumor visualization resulted even though a decrease in tumor blood flow had occurred. The angiographic image is related therefore to the lack of vasoconstriction in the tumor feeder vessel, which has, however, a decreased blood flow and the correspondingly greater volume of normally constricting hepatic arteries which results in a marked decrease in the background of vessels upon which the tumor image is superimposed.

Hypertrophic protein-losing gastropathy and vitiligo. Report of a second case

A second patient with hypertrophic protein-losing gastropathy and extensive vitiligo was studied. Upper gastrointestinal radiographs and endoscopy revealed multiple polyps of the upper half of the stomach. The patient was achlorhydric to pentagastrin stimulation. Clearance of 51Cr-labeled protein by the gastrointestinal tract was about 15 times normal. A total gastrectomy was done for relief of persistent epigastric pain and correction of hypoproteinemia. Histologically the polyps consisted of hypertrophied mucosal glands with cystic dilatation deep to the glandular layer. The similarity of this patient to a patient previously seen at our hospital led us to report the possible association of hypertrophic protein-losing gastropathy with vitiligo.

A simple cell-suspension method for transplantation of V2 carcinoma

A simple and rapid method for the preparation of an essentially monodispersed cell suspension from the rabbit V2 carcinoma, suitable for either large or small amounts of tumor tissue, did not require specialized equipment and yielded relatively large numbers of viable cells. Cell suspensions prepared by this method could be used to approximate a dose-response curve relating the percentage of tumor takes to the number of cells inoculated and could allow quantitative correlations not possible when macroscopic tumor fragments are used for implantation. The method, or slight modifications of it, should prove suitable for most tissues with a significant connective tissue component.

Adhesive tape: potential source of nosocomial bacteria

During a 7-day period, a variety of bacteria, including opportunistic ones, were recovered from 23 rolls of adhesive tape being used in a 16-bed intensive care unit. All rolls of tape were sterile when received from the manufacturer. Mixed flora was recovered from a total of 15 rolls, whereas eight rolls yielded pure cultures. Organisms recovered included Staphylococcus aureus, Pseudomonas aeruginosa, and various species of Enterobacteriaceae. Although no illness or infection arising directly from contaminated adhesive tape has been documented, we feel that a potential source of infection has been identified. Most important is the fact that such tape may contaminate the hands of personnel who handle it. Also, the adhesive tape may directly contaminate a patient since it is widely used to secure artificial airways and various drainage tubes which results in the tape coming into close contact with the mucous membranes lining the patient's respiratory and urogenital tracts.

Irreversible inhibition of nuclear exoribonuclease by thymidine-3'-fluorophosphate and p-haloacetamidophenyl nucleotides

Exoribonuclease purified from Ehrlich ascites tumor cell nuclei and in intact HeLa cell nuclei is irreversibly inactivated by tow concentrations of p-bromo- and p-iodoacetamidophenyl nucleotides and by thymidine-3'-fluorophosphate. Iodoacetate, bromoacetate, and thymidine-5'-fluorophosphate do not affect the enzyme. Although p-haloacetamidophenyl nucleotides inactivate ribonucleic acid polymerase of isolated HeLa cell nuclei, thymidine-3'-fluorophosphate does not affect the activity of this enzyme in vitro.