Understanding burnout in Pediatric residency through the lens of the 'Areas of worklife'

BACKGROUND AND OBJECTIVES

Burnout is a widespread problem in medicine, especially among trainees. Despite this, data on effective interventions are limited. An organizational context for burnout entitled Areas of Worklife identified six areas of the work environment that can affect burnout through mismatches between individuals expectations of that area and the reality of the work environment. This study aimed to gain a deeper understanding of pediatric residents' perspectives of the Areas of Worklife to allow programs to utilize this framework in the development of future interventions.

METHODS

Using qualitative methodology founded in grounded theory, we employed an iterative data collection by conducting semi-structured interviews, until data saturation was achieved, with 15 pediatric residents in 2018. We recorded interviews and transcribed them verbatim. Content analysis was conducted concurrently with data collection using constant comparison methods; the principal investigator and co-investigators worked jointly to generate codes and identify themes.

RESULTS

Themes were identified for the individual Areas of Worklife that represented resident perspectives and mismatches with the work environment. Overall, patient care was a central focus connecting the areas of control, reward, values, and workload; themes in these areas concentrated on resident's ability to interact with and learn from patients.

CONCLUSIONS

Residents' definitions of the Areas of Worklife can be used to identify mismatches between residents' expectations and their work environment, which can inform organizational interventions. These findings highlight the importance of a patient-focused approach to residency training, which is consistent with literature that shows patient care is a means to find meaning in their work. Resident definitions of the Areas of Worklife offer residency programs a practical approach in their battle against burnout by providing focused direction to respond to resident needs and identify tangible targets for intervention.

The Senior Resident-Fellow Dynamic on Pediatric Hospital Medicine Teams: A Qualitative Study

BACKGROUND AND OBJECTIVES

With the Accreditation Council for Graduate Medical Education accreditation in place for pediatric hospital medicine (PHM) fellowships, fellows are playing a larger role in resident education. However, the impact of PHM fellows on pediatric residency training is not well described. We aimed to identify the factors that affect the dynamic between senior residents and fellows working together on PHM teams.

METHODS

In this qualitative study, we used purposive sampling and interviewed 15 senior residents and 8 PHM fellows between April and September 2020. We created a conceptual framework for the senior resident-fellow dynamic to develop the interview guide. Using verbatim transcripts uploaded into Dedoose software, 2 authors coded responses and identified themes using directed content analysis.

RESULTS

Twelve themes emerged as factors that impact the senior resident-fellow dynamic and fell into 6 categories: Team organization, role clarity, teaching, fellow approachability, decision-making, and attending involvement. Both senior residents and PHM fellows described an optimal dynamic in which a hierarchal approach to team structure, teaching, and decision-making is counterbalanced by fellow approachability. Role uncertainty, especially with increased attending involvement, led to conflict between residents and fellows.

CONCLUSIONS

This study demonstrated that a structured hierarchy surrounding supervision, decision-making, and teaching promoted level-appropriate autonomy for both senior residents and fellows. These findings can be used to design an intervention, such as a leadership curriculum for fellows and senior residents, to target behaviors that facilitate a stepwise approach to supervision and patient care.

Using the Assessment of Reasoning Tool to facilitate feedback about diagnostic reasoning

OBJECTIVES

Idiosyncratic approaches to reasoning among teachers and limited reliable workplace-based assessment and feedback methods make teaching diagnostic reasoning challenging. The Assessment of Reasoning Tool (ART) was developed to fill this gap, but its utility and feasibility in providing feedback to residents has not been studied. We evaluated how the ART was used to assess, teach, and guide feedback on diagnostic reasoning to pediatric interns.

METHODS

We used an integrated mixed-methods approach to evaluate how the ART facilitates the feedback process between clinical teachers and learners. We collected data from surveys of pediatric interns and interviews of hospital medicine faculty at Baylor College of Medicine from 2019 to 2020. Interns completed the survey each time they received feedback from their attending that was guided by the ART. The preliminary intern survey results informed the faculty interview questions. We integrated descriptive statistics of the survey with the thematic analysis of the transcribed interviews.

RESULTS

Survey data (52 survey responses from 38 interns) and transcribed interviews (10 faculty) were analyzed. The ART framework provided a shared mental model which facilitated a feedback conversation. The ART-guided feedback was highly rated in terms of structure, content, and clarity in goal-setting while enabling new learning opportunities. Barriers to using the ART included limited time and inter-faculty variability of its use.

CONCLUSIONS

The ART facilitated effective and feasible faculty feedback to interns on their diagnostic reasoning skills.

Gilteritinib as treatment for extra-medullary relapse of FLT3-ITD acute myeloid leukemia FLT3-ITD, after allogeneic haematopoietic stem cell transplantation

Case of a patient with acute myeloid leukemia (AML) positive for mutations in both genes NPM1 and FLT3-ITD who underwent two allogeneic haematopoietic stem cell transplants (HSCT); the second allograft one was followed by extramedullary relapse (granulocytic sarcoma of right breast), with blast cells positive for FLT3-ITDmutation.  Treatment with Gilteritinib, a second generation selective oral type I FLT3 inhibitor, was started after the second HSCT with complete regression of breast granulocytic sarcoma in absence of hematological and extra hematologic toxicity. We conclude that Gilteritinib can represent an effective therapy for extra hematologic relapse, with acceptable toxicity and outpatient management.

Chronic Ulcers and Malnutrition in an African Patient

An 11-year-old girl with a congenitally malformed left hand, sickle cell trait, asthma, and history of appendicitis was transferred from Zambia for evaluation and treatment of widespread suppurative and ulcerative skin lesions that typically appeared after trauma to her skin. The ulcers first presented 3 years earlier but had markedly worsened in the 9 months before transfer, spreading circumferentially on her extremities and abdomen at the site of an appendectomy. They were painful and did not resolve with multiple courses of intravenous antibiotics and close management by a pediatric infectious disease specialist working for a nongovernmental organization (NGO) in her home country. Per NGO records, she had previously been  average weight-for-age. On presentation after international transfer, she was severely malnourished, with lesions covering ∼35% of her body. In initial workup, leukocytosis of 21 × 10³ cells per μL (79% neutrophils), hemoglobin of 6.1 g/dL, and mean corpuscular volume of 66 fL were found. Iron studies revealed an iron level of 18 μg/dL, ferritin level of 55 ng/mL, total iron binding capacity of 222 μg/dL, and transferrin saturation of 8%. Inflammatory markers were elevated, C-reactive protein was 20.1 mg/dL, and the erythrocyte sedimentation rate was 131 mm/h. A chest computed tomography scan revealed bilateral pulmonary nodules, the largest in her left upper lobe measuring 2.4 × 2.0 × 1.9 cm. Our panel of experts reviews the evaluation and treatment of this patient with extensive suppurative and ulcerative skin lesions and the factors considered in offering charity care to international patients.

Caregivers' Perceptions and Hospital Experience After a Brief Resolved Unexplained Event: A Qualitative Study

BACKGROUND AND OBJECTIVES

The American Academy of Pediatrics published guidelines for evaluation and management of lower-risk infants for a brief resolved unexplained event (BRUE). The guideline identified gaps in knowledge related to caregiver satisfaction, anxiety, and family-centered educational strategies to improve caregiver experience and patient outcomes. The objective of this study was to understand caregivers' experience with hospitalization for infants with BRUE, including their perception of the hospital stay, the diagnosis of BRUE, and their feelings toward the upcoming discharge from the hospital.

METHODS

We conducted a qualitative study using semistructured interviews with caregivers of infants aged 0 to 12 months who were admitted to a quaternary care children's hospital for a BRUE. Interviews were conducted within 24 hours of discharge. Two investigators coded transcripts and identified themes using consensus.

RESULTS

Eighteen caregivers of 13 infants were interviewed. No infants met criteria for being low risk according to the American Academy of Pediatrics guidelines. The coding scheme produced 3 major themes. First, parents felt reassured by hospital monitoring, diagnostic evaluation, and staff support in the hospital. Second, parents felt unsettled by the uncertainty of the child's condition and whether BRUE's "unexplainable" quality is understood as being part of normal infant behavior. Third, these themes manifested as conflicting emotions about caregivers' readiness for discharge.

CONCLUSIONS

Although hospital monitoring may provide reassurance for some caregivers, they continue to struggle with the uncertainty of the diagnosis. Caregiver perspectives can inform physicians' strategies to improve hospital experience and discharge readiness.

Infection Control and the Need for Family-/Child-Centered Care

Patient- and family-centered care (FCC) has become central to the delivery of medical care over the last 20 years and has been shown to improve patient outcomes. Infection control practices have the potential to greatly influence family centeredness and care providers, and hospital personnel must consider the potential impacts of isolation and the use of personal protective equipment (PPE). Approaching infection control with the perspective of FCC requires balancing patient safety and overall patient well-being. In this chapter, authors consider infection control and the benefits of FCC, family and sibling visitation, the use of playrooms, animals in healthcare settings including animal-assisted interventions, the potential adverse effects of infection control practices, and strategies to mitigate these impacts.

Pediatric Rheumatology Curriculum for the Pediatrics Resident: A Case-Based Approach to Learning

INTRODUCTION

Pediatric rheumatologic disease occurs more frequently than several other chronic pediatric diseases but is often underrecognized. It is estimated that in the US, one in 250 children has some form of juvenile arthritis and 300,000 children have a form of rheumatologic disease. However, there are only approximately 400 practicing pediatric rheumatologists nationwide.

METHODS

Kern's six-step method was used to develop a pediatric rheumatology curriculum based on respondents' perceived lack of training and comfort with four key areas: workup, musculoskeletal exam, laboratory interpretation, and referral to rheumatology. These cases were developed for second-year pediatric and second- and third-year internal medicine-pediatric residents rotating with the service. The curriculum was composed of four 30-minute case discussions as well as an observed musculoskeletal exam session.

RESULTS

In 2017, weekly case study sessions reached 34 trainees. Survey results from these trainees are representative of our overall results and reveal that learners felt the content of the cases helped increase comfort with compiling pertinent history and information of symptoms consistent with autoimmune disease, recognizing physical exam findings of autoimmune disease, ordering and interpreting laboratory studies in children with concerns for autoimmune disease, and referring to pediatric rheumatology.

DISCUSSION

This case-based curriculum exposed residents to presentations of the more common autoimmune diseases encountered in the pediatric population. The curriculum helps fill a gap in pediatric training through increased exposure to this subset of chronic diseases and expands physical examination skills not typically taught in general pediatrics.

Teamwork on Rounds on an Inpatient Ward Team: An Ethnographic Study

BACKGROUND AND OBJECTIVES

Pediatric hospitalists are expected to be adept at effective teamwork; yet, studies in which researchers describe teamwork practices in general pediatric inpatient settings are lacking. Our aim in this study was to examine the roles that general pediatric team members assume in real-life settings and how team members conduct teamwork practices on family-centered rounds.

METHODS

In the ethnographic tradition, we observed a general pediatric team on a hospitalist service, focusing on family-centered rounds, and conducted in-depth interviews with interns, senior residents, and faculty. We collected data in the form of field notes from observations and transcribed interviews and used constant comparison methods to create codes and generate themes. We used Team Strategies and Tools to Enhance Performance and Patient Safety (TeamSTEPPS) as an analytic lens and organizing framework.

RESULTS

Communication occurred in both structured and unstructured ways. Situation monitoring happened during routines, such as running the list, and led to creating a plan of patient care through shared decision-making. Some leadership characteristics were not exclusive to 1 team member. Finally, mutual support occurred through task completion and empowering learners; for example, attending physicians empowered senior residents, who also helped interns.

CONCLUSIONS

Our findings aligned with some, but not all, teamwork principles from TeamSTEPPS; misalignment may be due to contextual factors, such as the need to provide medical education and the development of grassroots routines (eg, running the list). Context is a key consideration when developing interventions to enhance teamwork on inpatient medical wards.

Plasminogen Activator Inhibitor-1 (PAI-1) Promoter 4G/5G Genotype and Increased PAI-1 Circulating Levels in Postmenopausal Women with Coronary Artery Disease

Increased circulating levels of type 1 plasminogen activator inhibitor (PAI-1) have been associated with coronary artery disease (CAD). However, genetic and environmental determinants of PAI-1 expression are only partially understood. The levels of PAI-1 have been found to relate to 4/5 guanosine (4G/5G) polymorphism in the promoter region of the PAI-1 gene. The 4G allele in this polymorphism has been associated with higher levels of plasma PAI-1 activity, but despite the strong correlation between PAI-1 activity and antigen, no association has been found between PAI-1 antigen levels and the PAI-1 promoter 4G/5G genotype. The aim of the present study was to analyze the influence of the PAI-1 promoter 4G/5G genotype on PAI-1 levels in post-menopause women with coronary disease in comparison with healthy women in pre and postmenopausal status, and the influence of this genotype on variations in PAI-1 levels after hormone replacement therapy (HRT). No differences between 4G/5G allele distribution in the groups studied were observed. The group of postmenopausal women with CAD showed significantly increased PAI-1 antigen and activity levels in comparison with the control groups, and the levels of PAI-1 correlated with the 4G/5G genotype. A multivariate analysis revealed that in the CAD group there was a high correlation between 4G allele dosage and PAI-1 antigen levels, which were also influenced by the triglyceride levels but not by estrogen or glucose levels. After hormone replacement therapy the decrease in PAI-1 levels was correlated with the 4G allele dosage. We conclude that in the group of postmenopausal women with CAD the influence of the PAI-1 promoter 4G/5G genotype on PAI-1 levels is more evident than in the control groups, and that the decrease in PAI-1 levels after HRT in CAD women correlates with the 4G allele dosage.

Mechanical analysis of the roundhouse kick according to height and distance in taekwondo

Competition regulation in taekwondo has experienced several changes during the last few years, for example, kicks to the head score more points than kicks to the chest. In addition, some external factors such as the height of target and execution distance seem to affect the kick performance. The aim of this study was to analyse selected biomechanical parameters (impact force, reaction time, and execution time) according to the height and execution distance in two different male groups (experts (n = 12) and novices (n = 21)). Athletes kicked twice from every execution distance (short, normal and long) and towards two different heights of target (chest and head) in a random order. Novices kicked to the head with a longer reaction time than to the chest (p < 0.05) but experts were able to kick with similar performance for both heights. From short and normal distances experts kicked with similar performance; whereas from the normal distance novices had longer reaction and execution time than from the short distance (p < 0.05). In conclusion, in counterattacking situations, experts should perform the roundhouse kick to the head instead of to the chest, because it produces better scores with similar performance; whereas novice athletes should avoid kicking to the head because they are not able to kick with similar performance. Moreover, it is recommended that during counterattacks higher-level taekwondo athletes should intend to kick from normal distances.

Relationship between optimism, disease variables, and health perception and quality of life in individuals with epilepsy

Epilepsy is a relatively frequent chronic condition with an important impact on the health perception and quality of life (QOL) of patients. The aim of the present study was to identify variables related to health status perception and QOL in persons with epilepsy. Participants were 200 persons with epilepsy, 53.5% of whom were males. The mean age was 39.6; 95% had seizures, and 99% were taking antiepileptic medication. The self-report questionnaire administered assessed four types of variables: demographic, disease, epilepsy-specific optimistic attitude, and outcome variables. Results demonstrated that an optimistic orientation is related to better perception of physical and mental health status and better perception of QOL. The variables that best predict positive outcomes are optimistic orientation, perception of cognitive functioning, and perception of seizure control. These results question the importance attributed to seizure characteristics for everyday functioning and everyday life of individuals with epilepsy, and stress the importance of facilitating an epilepsy-specific optimistic orientation.

Temporal lobe epilepsy surgery: different surgical strategies after a non-invasive diagnostic protocol

AIM

To test a non-invasive presurgical protocol for temporal lobe epilepsy (TLE) based on "anatomo-electro-clinical correlations".

METHODS

All consecutive patients with suspected TLE and seizure history <2 years were entered into the protocol, which included video-electroencephalographic (EEG) monitoring and magnetic resonance imaging (MRI). Three different TLE subsyndromes (mesial, lateral, mesiolateral) were identified by combined anatomical, electrical, and clinical criteria. "Tailored" surgery for each subsyndrome was offered. Patients with seizure history <2 years, MRI evidence of temporal mass lesion, and concordant interictal EEG and clinical data bypassed video-EEG monitoring and were directly scheduled for surgery.

RESULTS

Lesionectomy was performed without video-EEG recording in 11 patients with tumorous TLE. Of 146 patients studied with video-EEG, 133 received a TLE diagnosis. Four were excluded for neuropsychological risks, eight refused surgery, and 121 underwent surgery. Of 132 consecutive patients who underwent surgery, 101 had at least one year of follow up. They were divided into a "hippocampal sclerosis/cryptogenic" group (n = 57) and a "tumours/cortical organisation disorders" group (n = 44). In the first group, extensive temporal lobectomy (ETL) was performed in 40 patients, anteromesial temporal lobectomy (AMTL) in 17 patients. At follow up, 47 patients were seizure free. In the second group, lesionectomy plus ETL was performed in 23 patients, lesionectomy plus AMTL in six patients, and lesionectomy alone in 15 patients. Thirty nine patients were seizure free.

CONCLUSIONS

These findings suggest that different TLE subsyndromes can be identified accurately using non-invasive anatomo-electro-clinical data and can be treated effectively and safely with tailored surgery.

Apoptosis is regulated by polyamines in the cell cycle of Chinese hamster ovary cells

This paper deals with the relationship between the polyamine metabolism and apoptosis in the different phases of the cell cycle in a Chinese hamster ovary (CHO) cell line. Synchronously growing cells were obtained by the addition of 1.2 mM hydroxyurea and the progression through the cell cycle was monitored by determining the incorporation of 3H-thymidine in the DNA. Ornithine decarboxylase (ODC) activity showed a peak in S phase, while intracellular putrescine and spermine contents increased constantly, reaching to a maximum level at G2 phase; spermidine content doubled during G2 and increased four times during M, compared to G1. The increment in the endogenous polyamine content was associated to a diminished uptake from the medium. The apoptotic index was higher in G2 phase, coinciding with the maximum level observed in putrescine content. The results support the idea that intracellular putrescine level is closely related to apoptosis.

Plasminogen activator inhibitor-1 (PAI-1) promoter 4G/5G genotype and increased PAI-1 circulating levels in postmenopausal women with coronary artery disease

Increased circulating levels of type 1 plasminogen activator inhibitor (PAI-1) have been associated with coronary artery disease (CAD). However, genetic and environmental determinants of PAI-1 expression are only partially understood. The levels of PAI-1 have been found to relate to 4/5 guanosine (4G/5G) polymorphism in the promoter region of the PAI-1 gene. The 4G allele in this polymorphism has been associated with higher levels of plasma PAI-1 activity, but despite the strong correlation between PAI-1 activity and antigen, no association has been found between PAI-1 antigen levels and the PAI-1 promoter 4G/5G genotype. The aim of the present study was to analyze the influence of the PAI-1 promoter 4G/5G genotype on PAI-1 levels in post-menopause women with coronary disease in comparison with healthy women in pre and postmenopausal status, and the influence of this genotype on variations in PAI-1 levels after hormone replacement therapy (HRT). No differences between 4G/5G allele distribution in the groups studied were observed. The group of postmenopausal women with CAD showed significantly increased PAI-1 antigen and activity levels in comparison with the control groups, and the levels of PAI-1 correlated with the 4G/5G genotype. A multivariate analysis revealed that in the CAD group there was a high correlation between 4G allele dosage and PAI-1 antigen levels, which were also influenced by the triglyceride levels but not by estrogen or glucose levels. After hormone replacement therapy the decrease in PAI-1 levels was correlated with the 4G allele dosage. We conclude that in the group of postmenopausal women with CAD the influence of the PAI-1 promoter 4G/5G genotype on PAI-1 levels is more evident than in the control groups, and that the decrease in PAI-1 levels after HRT in CAD women correlates with the 4G allele dosage.

Organization and technical problems of LDL-apheresis

The Authors consider problems related to technique and organization of LDL-Apheresis with respect to some particular aspects. They evaluate: a) Technical complexity of procedures both in devices to use and in staff preparation; b) Length of treatment which conditions the other fields of activity; c) Problems in management treatments periodicity; d) Usually high cost of this kind of procedures; e) Problems related to vascular accesses; f) Problems related to pediatric patients, both for their low weight and vascular accesses; g) Management of cardio-vascular complications; h) Difficulties in evaluation of regression of vascular lesions. Finally, it is particularly difficult the management of psychological aspects related to somatic symptoms of the disease and to the acceptance of treatment.

Project of computer-aided management of therapeutical apheresis

The great increase in hemapheresis units activity that occurred during the last years caused the need for a computer-aided management (1, 2). We present a project for a data base system able to manage therapeutical apheresis (3). The program consists of five sections. a) Patient's file card: it allows to record anamnesis, examination and blood test results easily and under computer's guidance. b) Choice of therapeutic protocol: Therapeutic protocol is fixed in this section (device to be used, apheretic method, plasma volume to be processed, blood tests before and after apheresis). c)

PROCEDURES

It provides procedure's data entry and guides the operator during the treatment on the ground of therapeutical protocol. d) Data processing: It allows statistics on data placed in the data base. e) Registers: It includes both a general register and the possibility of search by disease, device and method.

Experience of computer-aided management of hemapheresis unit

Several programs are available for blood banks management but none of them is particularly made for hemapheresis. We studied a data base application able to manage any aspect of hemapheresis unit activity. The programming general criteria were: 1) easiness of use even for people without any previous experience in using Personal Computers; 2) maximum saving time in operating; 3) easily modifiable system in reply to problems or new needs; 4) automatic checks in order to have the highest automation together with the smallest error risk; 5) quick view on state of activity and on material consumption; 6) simplification of donor recruitment. After a three year long experience, we describe our program structure in order to give a basis for the development of a standardized management system which is useful for different needs and open to future applications of blood cell separators.

Experience of Computer-Aided Management of Hemapheresis Unit

Several programs are available for blood banks management but none of them is particularly made for hemapheresis.

We studied a data base application able to manage any aspect of hemapheresis unit activity. The programming general criteria were:

1) easiness of use even for people without any previous experience in using Personal Computers;

2) maximum saving time in operating;

3) easily modifiable system in reply to problems or new needs;

4) automatic checks in order to have the highest automation together with the smallest error risk;

5) quick view on state of activity and on material consumption;

6) simplification of donor recruitment.

After a three year long experience, we describe our program structure in order to give a basis for the development of a standardized management system which is useful for different needs and open to future applications of blood cell separators.

Organization and Technical Problems of LDL-apheresis

The Authors consider problems related to technique and organization of LDL-Apher-esis with respect to some particular aspects. They evaluate:

a) Technical complexity of procedures both in devices to use and in staff preparation;

b) Length of treatment which conditions the other fields of activity;

c) Problems in management treatments periodicity;

d) Usually high cost of this kind of procedures;

e) Problems related to vascular accesses;

f) Problems related to pediatric patients, both for their low weight and vascular accesses;

g) Management of cardiovascular complications;

h) Difficulties in evaluation of regression of vascular lesions.

Finally, it is particularly difficult the management of psychological aspects related to somatic symptoms of the disease and to the acceptance of treatment.

Project of Computer-aided Management of Therapeutical Apheresis

The great increase in hemapheresis units activity that occurred during the last years caused the need for a computer-aided management (1, 2).

We present a project for a data base system able to manage therapeutical apheresis (3). The program consists of five sections.

a) Patient's file card: it allows to record anamnesis, examination and blood test results easily and under computer's guidance.

b) Choice of therapeutic protocol: Therapeutic protocol is fixed in this section (device to be used, apheretic method, plasma volume to be processed, blood tests before and after apheresis).

c) Procedures: It provides procedure's data entry and guides the operator during the treatment on the ground of therapeutical protocol.

d) Data processing: It allows statistics on data placed in the data base.

e) Registers: It includes both a general register and the possibility of search by disease, device and method.

Treatment of severe hypercholesterolaemia by LDL-apheresis

The most severe forms of hypercholesterolaemia scarcely respond to diet and conventional drugs administration and need, therefore, alternative treatments. Terapeutic Plasma Exchange demonstrated an improved survival of subjects with Familial Hypercholesterolaemia (FH) in spite of its limitations. Semi-selective and selective techniques have been developed in order to remove LDL cholesterol alone. We studied the efficiency in LDL removal both of membrane filtration as of dextrane sulphate adsorption on 14 FH patients, performing 302 procedures. Cholesterol extraction with the different methods was in the range of 40-65%. Mean cholesterol level was reduced from 7% to 64% depending on the protocol used. The procedures were all performed on an outpatient basis. Side effects occurred rarely and were always of not serious degree. The short and the middle term clinical effects of LDL-Apheresis are then evaluated.

Infrared prism coupling characterization and optimization via near-field m-line scanning

The use of a detailed analysis of the near-field m-line pattern to characterize and optimize prism coupling into infrared waveguides is described. Experimental results at 10.6 microm are presented which completely confirm the theoretical predictions.