[Comparative analysis of gerontologic prophylaxis efficiency and membranotropic action of various gas therapy]

The research was executed on 320 male patients aged 35-92 years with various polyorgan pathology in a compensation stage. The treatment by gases was used: hyperbaric oxygenation, dry carbonic acid baths, ozon therapy, hypo oxygen therapy and their combinations. On indicators of biological age various age-dependent geroprophylactics effect of gas therapy was established. On indicators of resistance of erythrocytes various safety of used modes was found.

[The influence of carbon dioxide baths differing in the total mineralization levels on the functional state of the cardiovascular system of the patients presenting with hypertensive disease associated with coronary heart disease]

The results of the study on the influence of carbon dioxide baths differing in the total mineralization levels on the clinical course of hypertensive disease associated with coronary heart disease and on various functional systems of the body. The data obtained provide an insight into the role of salt concentrations (10 and 20 g/l) in carbon dioxide bath water (1.2 g/l) applied for the traditional treatment of the patients with hypertensive disease associated with concomitant coronary heart disease and musculoskeletal pathology. Highly mineralized bath water has a greater influence on the functional state of the cardiovascular system by causing a more pronounced decrease in peripheral vascular resistance and hypotensive effect. Baths with a salt concentration of 20 g/l markedly reduced pain and had anti-inflammatory effect in the patients with pathology of support and locomotor organs.

[Carboxytherapy - supportive therapy in chronic wound treatment]

Carboxytherapy is a supportive method in chronic wound treatment conducted by cutaneous and subcutaneous injection of medical carbon dioxide (CO2). The primary effect of the injected CO2 is the correction of tissue hypoxia due to the Bohr effect. With its effects on endothelial growth factors, it stimulates neoangiogenesis and fibroblast collagen synthesis consequently leading to better wound healing. Carboxytherapy is used in many areas from chronic wound treatment, peripheral venous and arterial diseases, dermatological diseases, to cosmetic medicine. It is minimally invasive, patients take it well, it is economically acceptable, and it can be conducted in outpatient conditions by properly trained doctors. The application of new technologic innovations in the healing processes, education and teamwork combined with developed holistic individual approach ensure good cooperation and mutual doctor-patient communication, enhance patient care and improve their quality of life.

CARbon DIoxide for the treatment of Febrile seizures: rationale, feasibility, and design of the CARDIF-study

BACKGROUND

2-8% of all children aged between 6 months and 5 years have febrile seizures. Often these seizures cease spontaneously, however depending on different national guidelines, 20-40% of the patients would need therapeutic intervention. For seizures longer than 3-5 minutes application of rectal diazepam, buccal midazolam or sublingual lorazepam is recommended. Benzodiazepines may be ineffective in some patients or cause prolonged sedation and fatigue. Preclinical investigations in a rat model provided evidence that febrile seizures may be triggered by respiratory alkalosis, which was subsequently confirmed by a retrospective clinical observation. Further, individual therapeutic interventions demonstrated that a pCO2-elevation via re-breathing or inhalation of 5% CO2 instantly stopped the febrile seizures. Here, we present the protocol for an interventional clinical trial to test the hypothesis that the application of 5% CO2 is effective and safe to suppress febrile seizures in children.

METHODS

The CARDIF (CARbon DIoxide against Febrile seizures) trial is a monocentric, prospective, double-blind, placebo-controlled, randomized study. A total of 288 patients with a life history of at least one febrile seizure will be randomized to receive either carbogen (5% CO2 plus 95% O2) or placebo (100% O2). As recurrences of febrile seizures mainly occur at home, the study medication will be administered by the parents through a low-pressure can fitted with a respiratory mask. The primary outcome measure is the efficacy of carbogen to interrupt febrile seizures. As secondary outcome parameters we assess safety, practicability to use the can, quality of life, contentedness, anxiousness and mobility of the parents.

PROSPECT

The CARDIF trial has the potential to develop a new therapy for the suppression of febrile seizures by redressing the normal physiological state. This would offer an alternative to the currently suggested treatment with benzodiazepines. This study is an example of academic translational research from the study of animal physiology to a new therapy.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01370044.

Pattern of CAIX expression is prognostic for outcome and predicts response to ARCON in patients with laryngeal cancer treated in a phase III randomized trial

BACKGROUND AND PURPOSE

In a phase III trial in patients with advanced stage laryngeal carcinoma comparing ARCON (accelerated radiotherapy with carbogen breathing and nicotinamide) to accelerated radiotherapy alone (AR) the prognostic and predictive value of CAIX, a hypoxia-associated protein, was investigated.

MATERIAL AND METHODS

261 Paraffin embedded tumor biopsies and 79 fresh frozen biopsies from patients entered in the trial were immunohistochemically stained for CAIX. CAIX-fraction and CAIX expression pattern were related to tumor control and patient survival.

RESULTS

Low CAIX-fraction was prognostic for worse regional control and overall survival in patients treated with AR. Patients with a low CAIX-fraction treated with ARCON had better regional control and metastasis-free survival compared to AR (RC 97% vs 71%, p < 0.01 and MFS 92% vs 69%, p = 0.06). Patients with a perinecrotic CAIX staining pattern had a significantly worse local control, metastasis-free and overall survival compared to patients with a diffuse pattern (65% vs 84%, p = 0.01, 70% vs 96%, p < 0.01 and 42% vs 71%, p < 0.01 respectively), and this could not be improved with ARCON. After multivariate analysis CAIX pattern and N-stage emerged as significant predictors for metastasis-free survival and overall survival.

CONCLUSIONS

ARCON improves regional control and metastasis-free survival only in patients with low CAIX expression. The different patterns of CAIX expression suggest different mechanisms of upregulation and have important prognostic value.

Transcutaneous application of carbon dioxide (CO2) induces mitochondrial apoptosis in human malignant fibrous histiocytoma in vivo

Mitochondria play an essential role in cellular energy metabolism and apoptosis. Previous studies have demonstrated that decreased mitochondrial biogenesis is associated with cancer progression. In mitochondrial biogenesis, peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) regulates the activities of multiple nuclear receptors and transcription factors involved in mitochondrial proliferation. Previously, we showed that overexpression of PGC-1α leads to mitochondrial proliferation and induces apoptosis in human malignant fibrous histiocytoma (MFH) cells in vitro. We also demonstrated that transcutaneous application of carbon dioxide (CO₂) to rat skeletal muscle induces PGC-1α expression and causes an increase in mitochondrial proliferation. In this study, we utilized a murine model of human MFH to determine the effect of transcutaneous CO₂ exposure on PGC-1α expression, mitochondrial proliferation and cellular apoptosis. PGC-1α expression was evaluated by quantitative real-time PCR, while mitochondrial proliferation was assessed by immunofluorescence staining and the relative copy number of mitochondrial DNA (mtDNA) was assessed by real-time PCR. Immunofluorescence staining and DNA fragmentation assays were used to examine mitochondrial apoptosis. We also evaluated the expression of mitochondrial apoptosis related proteins, such as caspases, cytochorome c and Bax, by immunoblot analysis. We show that transcutaneous application of CO₂ induces PGC-1α expression, and increases mitochondrial proliferation and apoptosis of tumor cells, significantly reducing tumor volume. Proteins involved in the mitochondrial apoptotic cascade, including caspase 3 and caspase 9, were elevated in CO₂ treated tumors compared to control. We also observed an enrichment of cytochrome c in the cytoplasmic fraction and Bax protein in the mitochondrial fraction of CO₂ treated tumors, highlighting the involvement of mitochondria in apoptosis. These data indicate that transcutaneous application of CO₂ may represent a novel therapeutic tool in the treatment of human MFH.

Therapeutic effects of carbogen inhalation and lipo-prostaglandin E1 in sudden hearing loss

PURPOSE

Vascular disorders and viral infections are considered the main causes of sudden hearing loss (SHL), although its pathogenesis remain unclear. Treatments include carbogen inhalation and lipo-prostaglandin E1 (lipo-PGE1), both of which have circulation-enhancing effects. We investigated the effectiveness of carbogen inhalation and lipo-PGE1 in SHL.

MATERIALS AND METHODS

This retrospective review included 202 patients with idiopathic SHL who visited our clinic within 14 days of symptom onset between January 2006 and June 2010. All patients received oral prednisolone for 10 days. Of the 202 patients, 44 received no additional treatment, 106 received additional carbogen inhalation, and 52 received additional lipo-PGE1. Hearing improvement was measured using Siegel's criteria.

RESULTS

Overall recovery rates were 67.9% in the carbogen group, 53.8% in the lipo-PGE1 group, and 52.3% in the steroid-only control group (p=0.097). Limited to type 1 and type 2 categories of Sigels's criteria, the carbogen group had a significantly higher recovery rate (53.8%) than the lipo-PGE1 group (26.9%) and the steroid-only control group (38.6%) (p=0.005).

CONCLUSION

Carbogen inhalation added to steroid was a more effective treatment than lipo-PGE1 added to steroid or steroid alone in patients with SHL.

Dynamic CO₂ inhalation: a novel treatment for CSR-CSA associated with CHF

BACKGROUND

Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) is very common in patients with chronic congestive heart failure (CHF). A current concept of the key pathophysiological mechanism leading to CSR-CSA is a fluctuation of PaCO2 below and above the apneic threshold. A number of therapeutic approaches for CSR-CSA have been proposed-all with varying success, some of which include various modes of positive airway pressure among other strategies. However, CO2 oscillations seen in CSR-CSA have yet to be looked at as a specific therapeutic target by current treatments.

DISCUSSION

Previous studies have shown that delivery of constant CO2 is efficacious in eliminating CSR-CSA by raising PaCO2, but there are serious concerns about the potential side effects, such as unwanted elevations in ventilation, work of breathing, and sympathetic nerve activity (SNA), and consequently CO2 inhalation therapy has not been recommended as a routine option for therapy. However, recent new studies into CO2 inhalation therapy have been made that may reshape its role as therapeutic. In this review, we will focus on the recent developments of administration of dynamic CO2 in the management of CSR-CSA in CHF patients.

Rapid elimination of CO through the lungs: coming full circle 100 years on

At the start of the 20th century, CO poisoning was treated by administering a combination of CO(2) and O(2) (carbogen) to stimulate ventilation. This treatment was reported to be highly effective, even reversing the deep coma of severe CO poisoning before patients arrived at the hospital. The efficacy of carbogen in treating CO poisoning was initially attributed to the absorption of CO(2); however, it was eventually realized that the increase in pulmonary ventilation was the predominant factor accelerating clearance of CO from the blood. The inhaled CO(2) in the carbogen stimulated ventilation but prevented hypocapnia and the resulting reductions in cerebral blood flow. By then, however, carbogen treatment for CO poisoning had been abandoned in favour of hyperbaric O(2). Now, a half-century later, there is accumulating evidence that hyperbaric O(2) is not efficacious, most probably because of delays in initiating treatment. We now also know that increases in pulmonary ventilation with O(2)-enriched gas can clear CO from the blood as fast, or very nearly as fast, as hyperbaric O(2). Compared with hyperbaric O(2), the technology for accelerating pulmonary clearance of CO with hyperoxic gas is not only portable and inexpensive, but also may be far more effective because treatment can be initiated sooner. In addition, the technology can be distributed more widely, especially in developing countries where the prevalence of CO poisoning is highest. Finally, early pulmonary CO clearance does not delay or preclude any other treatment, including subsequent treatment with hyperbaric O(2).

Carbon dioxide balneotherapy and cardiovascular disease

Carbon dioxide (CO(2)) balneotherapy is a kind of remedy with a wide spectrum of applications which have been used since the Middle Ages. However, its potential use as an adjuvant therapeutic option in patients with cardiovascular disease is not yet fully clarified. We performed a thorough review of MEDLINE Database, EMBASE, ISI WEB of Knowledge, COCHRANE database and sites funded by balneotherapy centers across Europe in order to recognize relevant studies and aggregate evidence supporting the use of CO(2) baths in various cardiovascular diseases. The three main effects of CO(2) hydrotherapy during whole body or partial immersion, including decline in core temperature, an increase in cutaneous blood flow, and an elevation of the score on thermal sensation, are analyzed on a pathophysiology basis. Additionally, the indications and contra-indications of the method are presented in an evidence-based way, while the need for new methodologically sufficient studies examining the use of CO(2) baths in other cardiovascular substrates is discussed.

Sudden sensorineural hearing loss after varicose vein surgery under general anesthesia. Case report

Sudden sensorineural hearing loss following non-otologic surgery, under general anesthesia, is an extremely rare complication. Furthermore, postoperative deafness has more commonly been associated with cardiac surgery. This acute dysfunction of the inner ear consists a controversial subject in terms of etiopathogenic mechanisms and treatment modalities. We present the case of a 60-year-old male patient who underwent varicose vein surgery under general anesthesia and presented immediately after the operation bilateral and profound impairment of his hearing acuity. A high index of suspicion is required to early diagnosis of this complication, although prompt treatment does not guarantee a good outcome.

Effects of hypercapnia and hypercapnic acidosis on attenuation of ventilator-associated lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are associated with impaired gas exchange, severe inflammation and alveolar damage including cell death. Patients with ALI or ARDS typically experience respiratory failure and thus require mechanical ventilation for support, which itself can aggravate lung injury. Recent developments in this field have revealed several therapeutic strategies that improve gas exchange, increase survival and minimize the deleterious effects of mechanical ventilation. Among those strategies is the reduction in tidal volume and allowing hypercapnia to develop during ventilation, or actively inducing hypercapnia. Here, we provide an overview of hypercapnia and the hypercapnic acidosis that typically follows, as well as the therapeutic effects of hypercapnia and acidosis in clinical studies and experimental models of ALI. Specifically, we review the effects of hypercapnia and acidosis on the attenuation of pulmonary inflammation, reduction of apoptosis in alveolar epithelial cells, improvement in sepsis-induced ALI and the therapeutic effects on other organ systems, as well as the potentially harmful effects of these strategies. The clinical implications of hypercapnia and hypercapnic acidosis are still not entirely clear. However, future research should focus on the intracellular signaling pathways that mediate ALI development, potentially focusing on the role of reactive biological species in ALI pathogenesis. Future research can also elucidate how such pathways may be targeted by hypercapnia and hypercapnic acidosis to attenuate lung injury.

Effect of immersion in CO2-enriched water on free radical release and total antioxidant status in peripheral arterial occlusive disease

AIM

The aim of this paper was to investigate the release of oxygen free radicals in patients with peripheral occlusive arterial disease and the effects of immersion of the legs and feet in carbon dioxide (CO(2))-enriched water.

METHODS

Twenty-five patients with peripheral occlusive arterial disease (Fontaine stage II) and 15 healthy controls were treated by immersing the lower legs in either CO(2)-enriched or normal spa water. Blood samples were collected in heparinized tubes and total antioxidant status (TAS) and reactive oxygen metabolites (ROMs) were measured after five treatments a week for two weeks.

RESULTS

d-ROM plasma levels decreased in patients with peripheral occlusive disease after immersion in CO(2)-enriched water (P<0.001), and in healthy controls (P<0.01), in line with a significant increase in TAS (P<0.001).

CONCLUSION

CO(2)-enriched water immersion had a positive effect, reducing free radical plasma levels and raising the levels of antioxidants, suggesting an improvement in the microcirculation.

[Combined application of interference therapy and "dry" carbon dioxide baths for the treatment of hemodynamic disorders in patients with implantation failure due to inflammation]

This work was designed to evaluate the influence of different physiotherapeutic modalities on the possibility of implantation, development and outcome of pregnancy in patients with chronic endometriosis and previous failures of implantation. The study confirmed initial sonographic changes and deficit of uterine blood supply as well as gradual improvement of these parameters under effect of adequate physiotherapy. Inclusion of dry carbon dioxide baths in the combined treatment of hemodynamic disorders made it possible to "prepare" endometrium for implantation and optimize blood circulation in the uterine vasculature in order to enhance the probability of implantation, development of pregnancy, and its success.

Effects of therapeutic hypercapnia on inflammation and apoptosis after hepatic ischemia-reperfusion injury in rats

BACKGROUND

Therapeutic hypercapnia (TH) has been demonstrated to protect several organs ischemia-reperfusion injury. The study aimed to investigate the effects of therapeutic hypercapnia on hepatic ischemia-reperfusion injury (HIRI).

METHODS

Thirty adult male Wistar rats weighing (250+/-20) g were randomized into 3 groups (n=10 in each), group C (control group), group A (hypercapnia group) and group B (CO2 preconditioning group). A segmental ischemia of the liver was induced by interrupting the blood vessels including the bile duct to the median and left lateral lobes for 60 minutes and all the animals were sacrificed after 240 minutes observation period of reperfusion. Mean arterial pressure (MAP) and the blood gases were measured before ischemia (baseline) and at 30, 60, 120, 180 and 240 minutes after reperfusion. Arterial blood samples were obtained for determination of serum levels of TNF-alpha, IL-10, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The histopathology of liver tissues was evaluated by light microscopy. The NF-kappaB expression and apoptotic hepatocytes were respectively determined by immunohistochemistry and TUNEL assay.

RESULTS

The serum levels of liver enzymes and TNF-alpha were significantly decreased while the IL-10 level was significantly increased in groups A and B than in group C (P<0.05), and group B surpassed group A (P<0.05). The histopathological scores, the NF-kappaB immunohistochemical score (IHS) and apoptotic index were significantly lower in groups A and B than in group C (P<0.05), and the decrease in group B was more obvious than in group A (P<0.05).

CONCLUSION

Therapeutic hypercapnia attenuates ischemia-reperfusion injury to the liver. Moreover, the effects of CO2 preconditioning are outstandingly notable.

[Carbon dioxide baths: state of the art]

Modern concepts of the mechanism of therapeutic action of carbon dioxide are reviewed with special reference to its effects on the patients with different pathologies undergoing treatment with the use of carbon dioxide baths. Further prospects for practical application of this method are discussed.

[Permissive and non-permissive hypercapnia: mechanisms of action and consequences of high carbon dioxide levels]

Acute lung injury is a disease with high incidence of mortality and its treatment is still controversial. Increasing the levels of CO2 beyond the physiological range has been proposed as a potential protective strategy for patients on mechanical ventilation, as it could moderate the inflammatory response. In this article we review the published evidence on the role of CO2 during acute lung injury. We conclude that although there are reports suggesting benefits from hypercapnia, more recent evidence suggests that hypercapnia could be deleterious, contributing to worsening of the lung injury.

Carbon dioxide therapy in the treatment of cellulite: an audit of clinical practice

BACKGROUND

The clinical practice of using carbon dioxide therapy for localized adiposities was audited over a 4-year period.

METHODS

Patients receiving physical, dietary, or drug concurrent therapy were excluded from the audit. Original measurements in terms of mean +/- standard error of the mean (SEM) were compared with those obtained after five sessions.

RESULTS

This series included 101 women who underwent abdominal therapy. Significant reduction (p < 0.05) in mean upper, mid, and lower abdomen circumference was experienced by all three age groups: respectively, 1.8 +/- 0.5, 1.6 +/- 0.4, and 2.1 +/- 0.3 cm in the 20- to 29-year- old group, 1.6 +/- 0.4, 2.3 +/- 0.3, and 2.1 +/- 0.3 cm in the 30- to 39-year-old group, and 2.0 +/- 0.4, 2.5 +/- 0.4, and 2.6 +/- 0.4 cm in the 40- to 50-year-old group. For 57 women who underwent localized thigh therapy (27 in the 20- to 29-year-old group, 18 in the 30- to 39-year-old group, and 12 in the 40- to 50-year-old group), thigh circumference was significantly reduced in the right versus left thigh: respectively, 1.6 +/- 0.3 versus 1.5 +/- 0.2 cm, 1.1 +/- 0.3 versus 1.1 +/- 0.3 cm, 1.6 +/- 0.3 versus 1.5 +/- 0.4. Weight loss was significant for older women who underwent abdominal therapy: 1.3 +/- 0.2 kg in the 30- to 39-year-old group (n = 43) and 1.3 +/- 0.2 kg in the 40- to 50 year-old group (n = 29). Older women who underwent thigh therapy also recorded significant weight reduction: 0.9 +/- 0.4 kg in the 30- to 39-year-old group (n = 18) and 1.6 +/- 0.3 kg in the 40- to 50-year-old group (n = 12). The results for 10 men were not significant.

CONCLUSION

These results agree with those reported originally and demonstrate that carboxytherapy is safe and effective.

The role of carbon dioxide therapy in the treatment of chronic wounds

A wound is defined as chronic when it does not heal according to the normal repair times and mechanisms. This particular condition may be principally due to local hypoxia. Carbon dioxide (CO(2)) therapy refers to the transcutaneous or subcutaneous administration of CO(2) for therapeutical effects on both microcirculation and tissue oxygenation. In this study, we report the clinical and instrumental results of the application of CO(2) in the therapy of chronic wounds. The study included 70 patients affected by chronic ulcers. The patients were selected by aetiology and wound extension and equally divided into two homogeneous groups. In group A, CO(2) therapy was used in addition to the routine methods of treatment for such lesions (surgical and/or chemical debridement, advanced dressings according to the features of each lesion). In group B, patients were treated using routine methods alone. Both groups underwent to instrumental (laser doppler flow, measurement of TcPO(2)), clinical and photographic evaluation. In the group that underwent subcutaneous treatment with CO(2) therapy, the results highlighted a significant increase in tissue oxygenation values, which was confirmed by greater progress of the lesions in terms of both healing and reduction of the injured area. Considering the safety, efficacy and reliability of this method, even if further studies are necessary, we believe that it is useful to include subcutaneous carbon dioxide therapy in the treatment of wounds involving hypoxia-related damage.

Effect of carbogen on tumour oxygenation and 32P-colloid interstitial irradiation response

BACKGROUND

Interstitial irradiation therapy using radionuclides is a slow and continual process in which the effect is exerted gradually, thus improvement of the hypoxic status of the tumor will also take a long time. It has been known that carbogen delivery of 5-15 min increases tumor oxygenation. However, the long-term effect of carbogen breathing on hypoxic cells has not yet been determined, and little is know about the effect of carbogen breathing for sensitization to interstitial irradiation therapy.

MATERIAL/METHODS

99mTc-HL91(99mTc 4,9-diaza-3,3,10,10-tetramethyldodecan-2,1-dione dioxime) hypoxic imaging was performed in 10 mice bearing sarcoma 180 (S180) before and after 2 h carbogen breathing. Radioactivity ratios of tumor to contralateral limbs (T/L) of the 2 images were calculated and compared. Mice bearing S180 were subjected to long-term carbogen breathing (2 h/day for 24 days), and were treated with or without 32P-colloid. Tumor growth rate was observed in the S180-bearing mice.

RESULTS

T/L of 99mTc-HL91 uptake before and after carbogen breathing was 1.872+/-0.391 and 1.354+/-0.189, respectively (t=4.476, P<0.01). In mice in the 32P-treated air breathing group and 32P-treated carbogen breathing group, tumor growth rate did not differ on day 12 after 32P-colloid treatment, and on day 24 the tumor volume was 2.728+/-0.469 and 2.237+/-0.603 cm3 (t=2.128, P<0.05), respectively, with tumor mass being 2.437+/-0.447 and 1.965+/-0.538 g (t=2.134, P<0.05), respectively.

CONCLUSIONS

Long-term carbogen breathing can increase tumor oxygenation and continual carbogen breathing is necessary for enhancing the therapeutic effect of 32P-colloid interstitial irradiation.

Vasodilators and vasoactive substances for idiopathic sudden sensorineural hearing loss

BACKGROUND

Idiopathic sudden sensorineural hearing loss (ISSHL) is sudden hearing loss where clinical assessment fails to reveal a cause. The most widely used therapeutic agents for ISSHL are antivirals, steroids, hyperbaric oxygen, vasodilators and rheological/vasoactive substances. There is currently conflicting evidence for vasodilator and vasoactive substances in the treatment of ISSHL.

OBJECTIVES

1. To determine the effectiveness of vasodilators and other vasoactive substances in improving hearing in patients with ISSHL. 2. To determine the adverse effects of these medications.

SEARCH STRATEGY

We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; CINAHL; Web of Science; Cambridge Scientific Abstracts; mRCT and additional sources for published and unpublished trials. The date of the most recent search was 16 September 2008.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of vasodilators/vasoactive substance versus placebo in the treatment of ISSHL. Trials were assessed for methodological quality.

DATA COLLECTION AND ANALYSIS

The authors assessed trials and extracted data independently. We contacted investigators to obtain additional information where necessary. Meta-analysis was neither possible nor considered appropriate due to the differences in the type of vasodilators used, dosage and duration of treatment. The quality and the result of each study was analysed and reported individually.

MAIN RESULTS

Only three trials, involving 189 participants, satisfied the inclusion criteria and these were of low methodological quality. One study showed a significant difference in hearing recovery in the vasodilator group (carbogen combined with a course of several other drugs) compared to the control group (a course of several other drugs alone). Another study only showed a significant improvement in higher frequencies in the vasodilator group (prostaglandin E1 + steroid) compared with the control group (placebo and steroid), no difference having been shown in overall hearing gain. In the third study the vasodilator group (naftidrofuryl and low-molecular weight dextran) showed an improvement only in lower frequencies over the control group (placebo and low-molecular weight dextran).Two of the studies reported adverse effects from vasodilator treatment, whereas there was no mention of any side effects in the third. Five patients in one study developed a sensation of heaviness in the head which settled spontaneously and did not interfere with treatment. In the other study one patient developed an allergic reaction and had to be excluded from the study.

AUTHORS' CONCLUSIONS

The effectiveness of vasodilators in the treatment of ISSHL remains unproven. The included studies were of relatively poor quality and the number of patients included was small. Moreover, there were differences in the type, dosage and duration of vasodilator used in each study. Due to the degree of heterogeneity the results could not be combined to reach a conclusion.

[Endoscopic thyroidectomy with filling the neck of rabbits with carbon dioxide and saline]

OBJECTIVE

The study was aimed to investigate the effects of different levels of pressure and duration of carbon dioxide and saline in the neck of rabbits on metabolic, hemodynamic, serum sodium concentrations and hematocrit changes.

METHOD

Twenty-one New Zealand rabbits were randomly divided into 7 groups according to the following pressure of CO2 or saline: 0 kPa, 0.67 kPa CO2, 1.33 kPa CO2, 2.00 kPa CO2, 0.67 kPa saline, 1.33 kPa saline, and 2.00 kPa saline. In order to make a space for the endoscopic thyroidectomy, we filled the neck of rabbits with carbon dioxide and saline. Arterial partial pressure of CO2 (PaCO2), pH, heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), serum sodium concentration and hematocrit were measured at baseline, 45 min and 90 min after filling with gas or saline and 30 min post-filling.

RESULT

Insufflation of CO2 at 0.67 kPa did not have any significant effect on the parameters, PaCO2 increased significantly 45 min and 90 min after insufflation of 1.33 kPa CO2 (P < 0.01). Marked changes in PaCO2, pH and CVP occurred 45 min and 90 min after insufflation of 2.00 kPa CO2 (P < 0.01), and the parameters did not return to baseline in 30 min after desufflation (P < 0.05). In animals receiving saline irrigation no significant changes occurred in PaCO2, pH and serum sodium concentrations at any time point. There was a tendency of decrease in HCT, but no statistically significant changes were found (P > 0.05). CVP increased significantly 90 min after saline irrigation at 1.33 kPa (P < 0.05). A significant increase in CVP occurred 45 min and 90 min after saline irrigation at 2.00 kPa (P < 0.05). No significant changes in HR and MAP occurred in all animals.

CONCLUSION

Filling with saline which does not cause hypercapnia, acidosis or dilutional hyponatremia can be used in endoscopic neck surgery to create and maintain a working space.