Sinus barotrauma in diving

INTRODUCTION

Sinus barotrauma is a common occurrence in diving and subaquatic medicine, potentially compromising dive safety. To gain a more thorough understanding of the condition, an in-depth investigation is justified.

METHODS

This was a survey study. An anonymous, electronic questionnaire was distributed to 7,060 recipients: professional divers of the Finnish Border Guard, the Finnish Rescue Services, and the Finnish Heritage agency, as well as recreational divers registered as members of the Finnish Divers' Association reachable by email (roughly two-thirds of all members and recreational divers in Finland). Primary outcomes were self-reported prevalence, clinical characteristics, and health effects of sinus barotrauma while diving. Secondary outcomes were adjusted odds ratios (OR) for frequency of sinus barotrauma with respect to possible risk factors.

RESULTS

In total, 1,881 respondents participated in the study (response rate 27%). A total of 49% of the respondents had experienced sinus barotrauma while diving and of those affected, 32% had used medications to alleviate their symptoms. The factors associated with sinus barotrauma were pollen allergies (OR 1.59; 95% CI 1.10-2.29), regular smoking (OR 2.04; 95% CI 1.07-3.91) and a high number of upper respiratory tract infections per year (≥ 3 vs. < 3 infections per year: OR 2.76; 95% CI 1.79-4.24).

CONCLUSIONS

Sinus barotrauma is the second most common condition encountered in diving medicine, having affected 49% of the respondents. Possible risk factors include allergies to pollen, regular smoking, and a high number of URTIs per year.

Middle ear barotrauma in diving

INTRODUCTION

Middle ear barotrauma (MEBt) is the most common medical complication in diving, posing a serious risk to dive safety. Given this prevalence and the continuing growth of the diving industry, a comprehensive overview of the condition is warranted.

METHODS

This was a survey study. An anonymous, electronic questionnaire was distributed to 7,060 recipients: professional divers of the Finnish Border Guard, the Finnish Rescue Services, and the Finnish Heritage agency; and recreational divers registered as members of the Finnish Divers' Association reachable by e-mail (roughly two-thirds of all members and recreational divers in Finland). Primary outcomes were self-reported prevalence, clinical characteristics, and health effects of MEBt while diving. Secondary outcomes were adjusted odds ratios (OR) for frequency of MEBt with respect to possible risk factors.

RESULTS

A total of 1,881 respondents participated in the study (response rate 27%). In total, 81% of the respondents had experienced MEBt while diving. Of those affected, 38% had used medications and 1% had undergone otorhinolaryngology-related surgical procedures due to MEBt. Factors most associated with MEBt were poor subjective success in Valsalva ('occasionally' versus 'always' successful: OR 11.56; 95% CI 7.24-18.47) and Toynbee ('occasionally' versus 'always' successful: OR 3.51; 95% CI 1.95-6.30) manoeuvres.

CONCLUSIONS

MEBt is common in both recreational and professional divers, having affected 81% of the respondents. The main possible risk factors include poor success in pressure equalisation manoeuvres.

Decompression illness (DCI) in Finland 1999-2018: Special emphasis on technical diving

INTRODUCTION

This is the first published study on decompression illness (DCI) and its treatment in Finland. Diving conditions are demanding, as even in the summer the water temperature below 20 meters' sea/fresh water (msw/mfw) is 4-10°C. Technical diving has become more popular over the years, so the emphasis of this study was to describe DCI in technical divers and compare it with non-technical recreational divers.

METHODS

This study includes by estimation over 95% of all hyperbaric oxygen-treated DCI patients during the years 1999-2018 (n = 571). The cases were divided into technical divers (n = 200) and non-technical divers (n = 371). We focused on the differences between these two groups. Technical diving was defined as the usage of mixed breathing gases, closed circuit rebreather diving or planned decompression diving.

RESULTS

The mean annual number of treated DCI cases in Finland was 29 (range 16-38). The number of divers treated possibly indicate a shift towards technical diving. Technical dives were deeper and longer and were mainly performed in cold water or an overhead environment. Technical divers were more likely to utilize first aid 100% oxygen (FAO₂) and sought medical attention earlier than non-technical divers. Symptom profiles were similar in both groups. Recompression was performed using USN Treatment Table Six in the majority of the cases and resulted in good final outcome. Eighty two percent were asymptomatic on completion of all recompression treatment(s).

CONCLUSION

This 20-year observational study indicates a shift towards technical diving, and hence a more demanding and challenging style of diving among Finnish divers, with a surprisingly constant number of DCI cases over the years. There is still need for improvement in divers' education in use of FAO₂ for DCI symptoms. Fortunately, the outcome after recompression therapy is generally successful.

Occurrence of human bocaviruses and parvovirus 4 in solid tissues

Human bocaviruses 1-4 (HBoV1-4) and parvovirus 4 (PARV4) are recently discovered human parvoviruses. HBoV1 is associated with respiratory infections of young children, while HBoV2-4 are enteric viruses. The clinical manifestations of PARV4 remain unknown. The objective of this study was to determine whether the DNAs of HBoV1-4 and PARV4 persist in human tissues long after primary infection. Biopsies of tonsillar tissue, skin, and synovia were examined for HBoV1-4 DNA and PARV4 DNA by PCR. Serum samples from the tissue donors were assayed for HBoV1 and PARV4 IgG and IgM antibodies. To obtain species-specific seroprevalences for HBoV1 and for HBoV2/3 combined, the sera were analyzed after virus-like particle (VLP) competition. While HBoV1 DNA was detected exclusively in the tonsillar tissues of 16/438 individuals (3.7%), all of them ≤8 years of age. HBoV2-4 and PARV4 DNAs were absent from all tissue types. HBoV1 IgG seroprevalence was 94.9%. No subject had HBoV1 or PARV4 IgM, nor did they have PARV4 IgG. The results indicate that HBoV1 DNA occurred in a small proportion of tonsils of young children after recent primary HBoV1 infection, but did not persist long in the other tissue types studied, unlike parvovirus B19 DNA. The results obtained by the PARV4 assays are in line with previous results on PARV4 epidemiology.

[Sinusitis or rhinosinusitis?]

Acute or chronic infections of nasal and paranasal sinuses are very common. Previously a clear-cut classification based on the anatomy of nasal and paranasal sinuses was used when referring to infection of this region. When symptoms of infection or inflammation were present only within the nasal cavity, the condition was called rhinitis. In case the patient presented with symptoms or findings within the paranasal sinuses, it was called sinusitis. Research data obtained during the last few decades have added the term rhinosinusitis to the applied terminology.

Acquisition of complement factor H is important for pathogenesis of Streptococcus pyogenes infections: evidence from bacterial in vitro survival and human genetic association

Streptococcus pyogenes (or group A streptococcus [GAS]) is a major human pathogen causing infections, such as tonsillitis, erysipelas, and sepsis. Several GAS strains bind host complement regulator factor H (CFH) via its domain 7 and, thereby, evade complement attack and C3b-mediated opsonophagocytosis. Importance of CFH binding for survival of GAS has been poorly studied because removal of CFH from plasma or blood causes vigorous complement activation, and specific inhibitors of the interaction have not been available. In this study, we found that activation of human complement by different GAS strains (n = 38) correlated negatively with binding of CFH via its domains 5-7. The importance of acquisition of host CFH for survival of GAS in vitro was studied next by blocking the binding with recombinant CFH5-7 lacking the regulatory domains 1-4. Using this fragment in full human blood resulted in death or radically reduced multiplication of all of the studied CFH-binding GAS strains. To study the importance of CFH binding in vivo (i.e., for pathogenesis of streptococcal infections), we used our recent finding that GAS binding to CFH is diminished in vitro by polymorphism 402H, which is also associated with age-related macular degeneration. We showed that allele 402H is suggested to be associated with protection from erysipelas (n = 278) and streptococcal tonsillitis (n = 209) compared with controls (n = 455) (p < 0.05). Taken together, the bacterial in vitro survival data and human genetic association revealed that binding of CFH is important for pathogenesis of GAS infections and suggested that inhibition of CFH binding can be a novel therapeutic approach in GAS infections.

Association of allergy, asthma and IgE sensitisation to adenoidectomy and infections in children

OBJECTIVE

To find out whether previous adenoidectomy is associated with asthma, allergic symptoms or allergen-specific IgE antibodies. RECRUITMENT AND METHODS: We recruited 213 paediatric patients admitted for elective tonsillectomy and 155 paediatric controls. Using a structured questionnaire, we recorded their respiratory symptoms, allergies, bronchial asthma and environmental factors. Serum IgE antibodies against respiratory allergens were screened. Patients were divided into those previously adenoidectomised (n = 100) or not adenoidectomised (n = 113).

RESULTS

Any allergy (p = 0.007) and non-antibiotic allergy diagnosed by a doctor (p = 0.015), and asthma (p = 0.015) were more common among adenoidectomised than non-adenoidectomised children under the age of seven. Between ages 7 and 11, neither any kind of allergy nor asthma were associated with earlier adenoidectomy. In the oldest age group (12 to 17), only antibiotic allergy was more common in adenoidectomised children. Recurrent otitis media (p < 0.001) and recurrent sinusitis (p = 0.007) were more common in adenoidectomised children. After controlling for recurrent respiratory infections, doctor-diagnosed allergy remained significantly associated with adenoidectomy in the youngest age group. Prevalence of specific IgE did not differ between the patient groups, or between school-aged patients and controls.

CONCLUSIONS

Our results suggest that hypersensitivity disorders and infections may share aetiological factors. However, as adenoidectomised children of any age did not have higher levels of specific IgE, it seems possible that allergy is either clinically over-diagnosed or insufficiently detected by serology among young adenoidectomised children.

Immunoglobulins and complement factor C4 in adult rhinosinusitis

We assessed whether complement and its factor C4 or abnormal immunoglobulin levels are associated with chronic or recurrent rhinosinusitis. We used multiple patient and control groups to obtain clinically meaningful data. Adult chronic or recurrent rhinosinusitis and acute purulent rhinosinusitis patients were compared with unselected adults and controls without previous rhinosinusitis. Associated clinical factors were reviewed. Levels of immunoglobulins, plasma C3, C4 and classical pathway haemolytic activity were analysed. C4 immunophenotyping was used to detect C4A and C4B deficiencies as null alleles. Complement was up-regulated in rhinosinusitis. C4A nulls and low IgA, IgG, IgG1, IgG2, IgG3 and IgG4 levels were all more common in chronic or recurrent rhinosinusitis patients than in unselected and healthy controls. We searched for relevant differences between the patient groups. According to stepwise logistic regression analysis, nasal polyposis [odds ratio (OR) 10.64, 95% confidence interval (CI) 2.5-45.7, P = 0.001], bronchial asthma (OR 8.87, 95% CI 2.3-34.9, P = 0.002), C4A null alleles (OR 5.84, 95% CI 1.4-24.9, P = 0.017) and low levels of IgG4 together with either IgG1 or IgG2 (OR 15.25, 95% CI 1.4-166.8, P = 0.026) were more common in chronic or recurrent rhinosinusitis than in acute rhinosinusitis patients. Isolated low IgG subclasses had limited value in patient assessment. C4A null alleles are associated with chronic or recurrent rhinosinusitis, potentially through their effect on immune defence and inflammation control. Multiple clinical and immunological parameters may need to be evaluated when searching for prognostic variables.

Rhinovirus/enterovirus RNA in tonsillar tissue of children with tonsillar disease

BACKGROUND

Human rhinoviruses (HRVs) together with the closely related human enteroviruses (HEVs) cause most of the acute respiratory illnesses throughout the year. HRVs have been detected in most parts of the respiratory tract but not in pharyngeal tonsils.

OBJECTIVES

We aimed to find out whether HRVs were detectable in tonsillar tissue and if their presence correlated to the tonsillar disease.

STUDY DESIGN

Thirty-three tonsillar samples collected in February-March 2003 from children with no acute respiratory symptoms were studied with HRV in situ hybridization (HRV-ISH). Ten tonsillar samples were further examined in a separate laboratory by two different reverse transcription polymerase chain reaction (RT-PCR) methods designed for detection of HRV/HEV RNA.

RESULTS

Twenty of the 33 samples (62%) were positive by HRV-ISH. Five positive and five negative HRV-ISH samples were investigated by two different PCR methods. HRV/HEV RNA was detected in 9 of the 10 specimens by a hanging drop-nested PCR. One HRV-ISH negative sample was positive by a conventional non-nested PCR. One of the samples studied by all three methods, from a patient with recurrent tonsillitis, had no detectable HRV/HEV RNA. Positive result in HRV-ISH did not correlate significantly with underlying tonsillar disease, history of respiratory infections or bronchial asthma. Altogether HRV/HEV RNA was detected in 75% of the tonsils with no correlation to patients' operation indication or history of respiratory diseases.

CONCLUSIONS

In February-March, HRV/HEV RNA was frequently found in tonsillar tissue in children irrespective of the tonsillar pathology. Whether detection of the RNA is a marker of chronic infection or is merely remnant of past infection is not known.