ABG Examples (ABG exam questions for medical students OSCEs and MRCP PACES). Below are some brief clinical scenarios with ABG results. Try to interpret each ABG and formulate a differential diagnosis before looking at the answer In epidemiology, prevalence is the proportion of a particular population found to be affected by a medical condition (typically a disease or a risk factor such as smoking or seatbelt use) at a specific time. It is derived by comparing the number of people found to have the condition with the total number of people studied and is usually expressed as a fraction, a percentage, or the number of by Respiratory Therapy Zone | Respiratory Fundamentals Airway Management refers to the procedure of ensuring that a patient is able to breathe by using a tube that is known as an artificial airway. It goes without saying that this is a very important topic in the field of Respiratory Care
Low-level laser (light) therapy (LLLT) in skin: stimulating, healing, restoring
Try out PMC Labs and tell us what you think. Learn More. Low-level laser light therapy LLLT is a fast-growing technology used to treat a multitude of conditions that require stimulation of healing, relief of pain and inflammation, and restoration of function.
Although the skin is the organ that is naturally exposed to light more than any other organ, it still responds well to red and near-infrared wavelengths. The photons are absorbed by mitochondrial chromophores in skin cells. Consequently electron transport, adenosine triphosphate ATP nitric oxide release, blood flow, reactive oxygen species increase and diverse signaling pathways get activated.
Stem cells can be activated allowing increased tissue repair and healing. In dermatology, LLLT has beneficial effects on wrinkles, acne scars, hypertrophic scars, and healing of burns. LLLT can reduce UV damage both as a treatment and as a prophylaxis. In pigmentary disorders such as vitiligo, case study examples respiratory therapy, LLLT can increase pigmentation by stimulating melanocyte proliferation and reduce depigmentation by inhibiting autoimmunity.
Inflammatory diseases such as psoriasis and acne can also benefit, case study examples respiratory therapy. The case study examples respiratory therapy nature and almost complete absence of side-effects encourages further testing in dermatology. Increasingly, non-invasive therapies for skin disease and skin rejuvenation are used, especially in Western countries where relatively high disposable incomes are combined with the desire for an ideal appearance fostered by societal pressures.
Although the skin is the organ that is naturally most exposed to light, it still responds well to red and near-infrared wavelengths delivered at the correct parameters with therapeutic intent.
Low-level laser therapy LLLT was discovered in the late s, but only in recent times has it been widely applied in dermatology. The introduction of light emitting diode LED devices has reduced many of the concerns formerly associated with lasers, such as expense, safety concerns and the need for trained personnel to operate them.
In fact, many LED devices are designed for home use and are widely sold on the internet. This review will cover the use of LLLT as possibly the ultimate non-invasive approach to treating the skin.
LLLT, phototherapy or photobiomodulation refers to the use of photons at a non-thermal irradiance to alter biological activity, case study examples respiratory therapy. LLLT uses either coherent light sources lasers or non-coherent light sources consisting of filtered lamps or light-emitting diodes LED or, on occasion, case study examples respiratory therapy combination of both.
The main medical applications of LLLT are reducing pain and inflammation, case study examples respiratory therapy, augmenting tissue repair and promoting regeneration of different tissues and nerves, and case study examples respiratory therapy tissue damage in situations where it is likely to occur.
More recently, this approach has also been used for inflammatory acne Table 1. Recently, medical treatment with LLLT at various intensities has been found to stimulate or inhibit an assortment of cellular processes. The mechanism associated with the cellular photobiostimulation by LLLT is not yet fully understood.
From observation, it appears that LLLT has a wide range of effects at the molecular, cellular, and tissue levels, case study examples respiratory therapy. The basic biological mechanism behind the effects of LLLT is thought to be through absorption of red and NIR light by mitochondrial chromophores, in particular cytochrome c oxidase CCO which is contained in the respiratory chain located within the mitochondria, 5 — 7 and perhaps also by photoacceptors in the plasma membrane of cells.
Consequently a cascade of events occur in the mitochondria, leading to biostimulation of various processes Figure 1. Basic biological mechanism behind the effects of LLLT is thought to be through absorption of red and NIR light by mitochondrial chromophores, in particular cytochrome c oxidase CCO which is contained in the respiratory chain located within the mitochondria 5 — 7.
It is hypothesized that this absorption of light energy may cause photodissociation of inhibitory nitric oxide from CCO 9 leading to enhancement of enzyme activity 10electron transport 11mitochondrial respiration and ATP production 12 — In turn, LLLT by altering the cellular redox state can induce the activation of numerous intracellular signaling pathways; alter the affinity of transcription factors concerned with cell proliferation, survival, tissue repair and regeneration 25615 Although LLLT is now used to treat a wide variety of ailments, it remains somewhat controversial as a therapy for 2 principle reasons.
First, there are uncertainties about the fundamental molecular and cellular mechanisms responsible for transducing signals from the photons incident on the cells to the biological effects that take place in the irradiated tissue.
Second, there are significant variations in terms of dosimetry parameters: wavelength, irradiance or power density, pulse structure, coherence, polarization, energy, fluence, irradiation time, contact vs non-contact application, and repetition regimen. Lower dosimetric parameters can result in reduced effectiveness of the treatment and higher ones can lead to tissue damage.
Many of the published studies on LLLT include negative results. It is possibly because of an inappropriate choice of light source and dosage. It is important to consider that there is an optimal dose of light for any particular application. Laser radiation or non-coherent light has a wavelength and radiant exposure dependent capability to alter cellular behavior in the absence of significant heating. In normal circumstances, it uses relatively low fluences 0.
One question that has not yet been conclusively answered is whether there is any advantage to using coherent laser light over non-coherent LED light. Skin starts showing its first signs of case study examples respiratory therapy in the late 20s to early 30s and it usually presents with wrinkles, dyspigmentation, telangiectasia, and loss of elasticity.
Common histologic and molecular-level features are reduction in the amount of collagen, fragmentation of collagen fibers, elastotic degeneration of elastic fibers, upregulation of matrix metalloproteinases MMPsespecially MMP-1 and MMP-2, dilated and tortuous dermal vessels, and atrophy and disorientation of the epidermis.
Several modalities have been developed in order to reverse the dermal and epidermal signs of photo- and chronological aging. The main concept of most of these modalities is removing the epidermis and inducing a controlled form of skin wounding in order to promote collagen biosynthesis and dermal matrix remodeling.
The most commonly used interventions as of today are retinoic acid a vitamin A derivativedermabrasion, chemical peels, case study examples respiratory therapy, and ablative laser resurfacing with carbon dioxide CO 2 or case study examples respiratory therapy yttrium-aluminum-garnet Er:YAG lasers or a combination of these wavelengths. LED which is a novel light source for non-thermal, non-ablative skin rejuvenation has been shown to be effective for improving wrinkles and skin laxity Figure 3.
Studies by Abergel et al. and Yu et al. reported an increase in production of pro-collagen, collagen, basic fibroblast growth factors bFGF and proliferation of fibroblasts after exposure to low-energy laser irradiation in vitro and in vivo animal models Figure 4.
Finally, an increase in the amount of collagen was demonstrated in the post-treatment specimens Pro-inflammatory cytokines IL-1β and TNF- α are thought to be recruited to heal the intentionally formed photothermally-mediated wounds associated with laser treatments, and this cascade of wound healing consequently contributes to new collagen synthesis.
When these observations are put together, it is possible that increased production of IL-1β and TNF- α might have induced MMPs in the early response to LED therapy.
This may clear the photodamaged collagen fragments to enable biosynthesis of new collagen fibers. Later on, an increase case study examples respiratory therapy the amount of TIMPs might protect the newly synthesized collagen from proteolytic degradation case study examples respiratory therapy MMPs. The results peaked at 4 to case study examples respiratory therapy months following completion of 8 treatments.
Markedly increased collagen in the papillary dermis and reduced MMP-1 were common findings. Barolet et al. LLLT aids skin rejuvenation through increasing collagen production and decreasing collagen degradation. Decrease in IL-6, and increase in TIMPs which in turn reduce MMPs all aid in reduction of collagen degradation. Pathogenesis of acne vulgaris has not yet been clarified, however current consensus is that it involves four main events: follicular hyperconification, increased sebum secretion effected by the androgenic hormone secretions, colonization of Propionibacterium acnes and case study examples respiratory therapy. acnes plays a key role by acting on triglycerides and releasing its cytokines which in turn trigger inflammatory reactions and alter infundibular keratinization.
In severe cases, systemic antibiotics such as tetracycline and doxycycline, oral retinoids, and some hormones are indicated. acnes, and inflammation. Phototherapy light, lasers, and photodynamic therapy has been proposed as an alternative therapeutic modality to treat acne vulgaris and was proposed to have less side effects compared to other treatment options.
Recently, phototherapy with visible light mainly blue light, red light or combination of both started being used in the treatment of acne Figure 3. acnes as a part of its normal metabolism, and that act as endogenous photosensitizers. Red and blue light when used in combination have synergistic effects in treatment of acne. acnes synthesizes and stores a large amount of porphyrins. Once the porphyrin is exposed to visible light specifically blue light it becomes chemically active and transfers to an excited state, resulting in formation of reactive free radicals and singlet oxygen which in turn causes membrane damage in P.
acnes 49 Red light is proposed to exert its effects through reducing the inflammatory process 51 Several studies reported that LLLT in the red to near infrared spectral range — nm and nonthermal power less than mW alone or in combination with other treatment modalities mainly blue lightis effective for treatment of acne vulgaris, case study examples respiratory therapy.
However sometimes sun avoidance might be hard to implement, especially for the people involved in outdoor occupations or leisure activities. On case study examples respiratory therapy other hand, the photoprotective efficacy of topical sunscreens have their own limitations as well, which include decreased efficacy following water exposure or perspiration, spectral limitations, possible toxic effects of nanoparticles that are contained by most sunscreens, 60 user allergies, and compliance.
In the natural environment, visible and IR solar wavelengths predominate in the morning and Case study examples respiratory therapy and UVA are maximal around noon which suggest that mammalians already possess a natural mechanism which, in reaction to morning IR radiation, prepares the skin for upcoming potentially damaging UV radiation at noon.
Menezes et al. demonstrated that non-coherent near infrared radiation Case study examples respiratory therapy —2, nm generated a strong cellular case study examples respiratory therapy against solar UV cytotoxicity in the absence of rising skin temperature and it was assumed to be a long-lasting at least 24 hours and cumulative phenomenon. proposed that IR irradiation prepares cells to resist UVB-induced damage by affecting case study examples respiratory therapy mitochondrial apoptotic pathway.
In a further study, Frank et al, case study examples respiratory therapy. studied more specifically the role of the p53 cell signaling pathway in the prevention of UVB toxicity. Finally, the IR induction of defense mechanisms was supported by Applegate et al. In an in vitro study, it was reported that an increase dermal fibroblast procollagen secretion reduces metalloproteinases MMP or collagenase production following non-thermal non-coherent deep red visible LED exposures nm, sequential pulsing mode.
Effects of non-thermal, non-coherent nm LED pulsed treatments in providing enhanced skin resistance prior to upcoming UV damage was investigated in a group of subjects with normal fair skin and patients presenting polymorphous light eruption PLE.
Results suggested that LED based therapy prior to UV exposure provided significant dose-related protection against UVB induced erythema.
Furthermore, a sun protection factor SPFlike effect and a reduction in post-inflammatory hyperpigmentation were observed. An in vitro study by Yu et al. revealed that HeNe laser irradiation stimulated an increase in nerve growth factor NGF release from cultured keratinocytes and its gene expression. One of the most common virus infections is caused by herpes simplex virus HSV. The exposure of the host to several kinds of physical or emotional stresses such as fever, exposure to UV light, and immune suppression causes virus reactivation and migration through sensory nerves to skin and mucosa, localizing particularly on the basal epithelium of the lips and the perioral area.
It is accompanied by case study examples respiratory therapy, burning, itching, or tingling at the site where the blisters form. Immune responses to HSV infection involve: macrophages, Langerhans cells, natural killer cells, lymphocyte-mediated delayed-type hypersensitivity, and cytotoxicity.
LLLT has been suggested as an alternative to current medications for accelerated healing, reducing symptoms and influencing the length of the recurrence period. However, irradiation did not effect established HSV latency in a murine model. Even though mechanism of action is still not clear, an indirect effect of LLLT on cellular and humoral components of the immune system involved in antiviral responses rather than a direct virus-inactivating effect was proposed.
investigated tuberculin reactions at the bilateral sites of the backs of sensitized guinea pigs, case study examples respiratory therapy. They applied a single low-power laser irradiation dose at a fluence of 3, case study examples respiratory therapy. It is worth to note that this phenomenon was observed when mononuclear cells were dominant in the perivascular cellular infiltration. Based on their results, case study examples respiratory therapy, they have suggested a possible systemic inhibitory effect of LLLT on delayed hypersensitivity reactions.
The question of whether these effects of LLLT have any influence on HSV infection remains to be determined.
How to Prepare for (and Pass) the Clinical Sims Exam
, time: 27:53ABG Examples (ABG exam questions for medical students and PACES) - Oxford Medical Education
by Respiratory Therapy Zone | Respiratory Fundamentals Airway Management refers to the procedure of ensuring that a patient is able to breathe by using a tube that is known as an artificial airway. It goes without saying that this is a very important topic in the field of Respiratory Care Oct 29, · In this case, the direction can be given in different forms (e.g., to the right, east, from A to D). Change in Velocity Llike speed, change in velocity can occur when an object speeds up and slows In epidemiology, prevalence is the proportion of a particular population found to be affected by a medical condition (typically a disease or a risk factor such as smoking or seatbelt use) at a specific time. It is derived by comparing the number of people found to have the condition with the total number of people studied and is usually expressed as a fraction, a percentage, or the number of
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