Komplikationer under anestesi hos hundar med kroppsvikt under 5 kg

Risken för anestesi- eller sederingsrelaterad död beräknas vara omkring 0,17 % hos hundar. I en studie har kroppsvikt under 5 kg visat sig bidra till nästan åtta gånger större risk för anestesirelaterad död jämfört med högre kroppsvikt. Studier som förklarar den ökade risken hos hundar under 5 kg är få. Denna studie har därför undersökt komplikationer under anestesi hos hundar med kroppsvikt under 5 kg. Hypotesen var att totalantalet komplikationer under anestesi är högre hos hundar under 5 kg än hundar över 20 kg och att hundar under 5 kg har ökad risk för hypotermi, hypoglykemi, reflux, regurgitation och aspiration. Studien har också undersökt faktorer som skulle kunna påverka kroppstemperaturen, blodglukosnivå, pH i esofagus och pH i trakea. Studien utfördes på SLU Universitetsdjursjukhuset i Uppsala under september och oktober 2020. Inklusionskriterierna var ålder över 1år, ASA-status 1–2 och kroppsvikt under 5 kg eller över 20 kg. I studien ingick arton hundar. Inga statistiskt signifikanta skillnader sågs avseende ålder, body condition score, anestesi- och operationstider, fastetider och medetomidindos mellan grupperna. Totalantalet komplikationer under anestesin skiljde sig inte mellan grupperna. En lägre kroppstemperatur registrerades under anestesi och under uppvak hos hundar under 5 kg trots mer användning av passiv och aktiv uppvärmning. Hos hundar med kroppsvikt under 5 kg var intervallet av rektaltemperatur i samband med anestesi mellan 34,9–39,4 °C och för hundar över 20 kg var intervallet mellan 36,1–39,1 °C. Återandningsgrad hade en positiv korrelation med vikt. Återandningsgrad och inandningsgasens temperatur var högre under anestesins senare delar hos större hundar jämfört med mindre hundar. Efter 90 minuters anestesi sågs en positiv korrelation mellan inandningsgastemperatur i anestesisystemet och kroppstemperatur samt återandningsgrad. Ingen korrelation kunde ses mellan kroppstemperatur och rumstemperatur eller temperatur under patienten. Hypoglykemi registrerades inte hos hundar under 5 kg, istället hade de högre blodglukosnivåer jämfört med hundar över 20 kg. Intervallet för blodglukos hos hundar under 5 kg var 3,8–13,9 mmol/L och hos hundar över 20 kg var motsvarande intervall 2,8–8,9 mmol/L. Ingen korrelation kunde ses mellan blodglukosnivåer och preoperativ fastetid, preoperativ stress, medetomidindos, stress under uppvak eller vokalisering under uppvak. En hund med kroppsvikt över 20 kg uppvisade pH värde i esofagus förenliga med reflux. Inga hundar i studien uppvisade regurgitation eller aspiration. Däremot sågs ett signifikant lägre pH i trakea hos hundar under 5 kg. Det fanns inga skillnader mellan grupperna avseende esofagus-pH. Ingen korrelation sågs mellan preoperativ fastetid och pH i esofagus eller trakea. En lägre kroppstemperatur hos hundar under 5 kg under anestesi i denna studie skulle kunna förklaras av deras stora kroppsyta i förhållande till kroppsmassa, lägre återandningsgrad som leder till lägre gastemperatur i anestesisystemet och större totalvolym intravenös vätsketerapi i förhållande till kroppsvikt. Högre glukosnivåer hos hundar under 5 kg skulle möjligtvis kunna förklaras av smärtrelaterad stressrespons eller hypotermi. Att inga hundar under 5 kg uppvisade reflux, regurgitation eller aspiration skulle kunna bero på lågt antal hundar i studien och låg upptäcktsgrad. Konklusion I denna pilotstudie har faktorer identifierats som skulle kunna ha betydelse för patientens säkerhet under anestesi men det förklarar inte den högre dödligheten hos hundar under 5 kg som beskrivs i litteraturen. Skillnader har identifierats mellan små och stora hundar avseende kroppstemperatur, återandningsgrad, blodglukosnivåer och pH i trakea. Fler studier krävs för att utvärdera betydelsen och orsak till komplikationerna som sågs i ökad frekvens hos hundarna under 5 kg.Studies in dogs have shown a 0,17 % risk of anesthesia and sedation related death. Dogs with body weight less than 5 kg have almost eight times higher risk to die in anesthesia related death than larger dogs. The causes of the higher risk are unknown. This study estimates the frequency of complications during anesthesia in dogs with a body weight less than 5 kg. The hypothesis is that dogs less than 5 kg shows hypothermia, hypoglycemia, reflux, regurgitation and aspiration more frequent than bigger dogs. The study also examines factors that could affect body temperature, blood glucose levels, pH in the esophagus and pH in the trachea. The study was performed at the SLU University Animal Hospital in Uppsala during September and October 2020. Eighteen anesthesia sessions were registered. The inclusion criteria were dogs older than 1 year, ASA score 1-2 and body weight less than 5 kg or over 20 kg. No statistically significant differences between the study groups were seen regarding age, body condition score, anesthesia time, surgery time, fasting time and medetomidine dose. No significant differences in number of complications were documented in this study between the study groups. A lower body temperature was recorded in dogs less than 5 kg during anesthesia and the first postoperative 60 minutes even if the small dogs used more heating devices. The interval of rectal temperature in the dogs less than 5 kg was between 34,9-39,4 °C and for dogs over 20 kg was 36,1-39,1 °C. The rebreathing level had a positive correlation with body weight. The level of rebreathing and air temperature in the anesthesia circuits was higher in dogs over 20 kg. After 90 minutes anesthesia a positive correlation could be seen between air temperature in the anesthesia circuits and body weight and the level of rebreathing. No correlation could be seen between body temperature and room temperature or temperature beneath the patient. No hypoglycemia was recorded in dogs less than 5 kg, instead higher blood glucose levels were registered in dogs less than 5 kg. The interval of blood glucose levels in dogs less than 5 kg was 3,8-13,9 mmol/L and for dogs over 20 kg 2,8-8,9 mmol/L. No correlation could be seen between blood glucose levels and preoperative fasting time, preoperative stress, dose of medetomidine, postoperative stress and postoperative vocalization. One dog with body weight over 20 kg hade pH in the esophagus that coincides with reflux. No dog in the study showed regurgitation or aspiration. A significant lower pH in the trachea was seen in dogs less than 5 kg but there were no differences between pH in the esophagus along the study groups. No correlation was seen between preoperative fasting time and pH in trachea or esophagus. A lower body temperature in dogs less than 5 kg during anesthesia could be a result of their larger body surface area in relation to their body mass, lower temperature of the inspired gas and higher volume of intravenous fluid therapy in relation to their body weight. Higher blood glucose levels in dogs less than 5 kg could possibly be a result of pain triggered stress and hypothermia. The factor that no dogs less than 5 kg showed reflux, regurgitation or aspiration could be related to the small number of dogs in the study and a low rate of detection. Conclusion This pilot study has found some factors that might be of importance for the safety during anesthesia. But it cannot explain the higher frequency of anesthesia related deaths in dogs less than 5 kg that has been reported in the literature. Some factors that differ between the study groups in this study material has been found. Differences between small and bigger dogs have been seen regarding body temperature, rebreathing level, blood glucose levels and pH in the trachea. More studies would be needed to show the importance and reason of the complications seen more frequently in dogs less than 5 kg in this study

Why give dogs core vaccination?

Vaccin efterliknar naturliga patogener och bidrar till bildande av immunologiskt skydd. Det ideala vaccinet skyddar mot replikation, spridning och sjukdom. I Sverige ingår canine distemper virus, hundens parvovirus och canine adenovirus i basvaccination. Smittspridning av virusen sker via oralt eller aerosolt intag av kontaminerade kroppsvätskor. Sjukdomar orsakade av dessa virus förekommer i hela världen men tack vare vaccination är de ovanliga i många länder. Vaccination är viktigt eftersom det inte finns någon annan behandling mot sjukdomarna. Denna litteraturstudie undersöker om det är nödvändigt att vaccinera hundar mot de virus som ingår i basvaccinationen, hur länge immunitet kvarstår efter en vaccination och hur en revaccination påverkar hundens skydd. Inom veterinärmedicin används framförallt levande attenuerat vaccin, avdödat vaccin och subenhetsvaccin. Vaccin innehållande antigen mot flera sjukdomar kallas kombinationspreparat och det kan innehålla en eller flera vaccintyper. Endast levande attenuerat vaccin, som ger upphov till högre antikroppstiter och kortare tid till immunologiskt skydd, finns godkänt idag i Sverige. Hur bra det immunologiska skyddet blir hos hunden är individuellt och tycks inte påverkas av ålder eller kön. Om levande attenuerat vaccin används kan immunitet kvarstå många år och ibland hela hundens liv. I Sverige består rekommenderad grundvaccination hos hund av 3 doser som ges fram tills 1 års ålder, förutsatt att levande attenuerat vaccin används. Vid användning av avdödat vaccin eller vid ökad smittrisk kan 4 vaccinationsdoser behövas. Därefter bör den vuxna hunden revaccineras vart tredje år. Revaccination påverkar framförallt immuniteten hos hundar med låga antikroppsnivåer eller avsaknad av immunitet. Avsaknad av immunologiskt skydd efter vaccination uppkommer oftast i närvaro av maternella antikroppar, vid felaktig administrering eller vid vaccination av immunsupprimerade individer. Revaccination är viktigt för att ge immunologiskt skydd hos hundar som saknar immunitet men bör inte göras för ofta för att undvika risk för reaktioner mot vaccin. En bedömning av nytta och risk bör göras för hundar innan vaccinering. Sjukdom orsakad av canine distemper virus, hundens parvovirus och canine adenovirus kan utan vaccination förekomma i hög frekvens och leda till död. Hos de flesta hundar ger vaccination upphov till minst tre års skydd vilket motsvarar det revaccinationsintervall som rekommenderas. Är större delen av en population vaccinerade kan prevalensen av sjukdom minska och individer med avsaknad av immunitet skyddas.Vaccination prevents infectious disease by generating immunity against a pathogen. An ideal vaccine prevents replication, proliferation, spread and development of disease. In Sweden vaccination against canine distemper virus, canine parvovirus and canine adenovirus are recommended. These viruses infect the body when contaminated body fluid get inhaled or ingested. The diseases are present all over the world but the prevalence is low in many countries because of vaccination programs. There is no treatment to these diseases, only prevention with vaccine. This thesis studies the importance of vaccination against these diseases, duration of immunity and effects of revaccination on the antibody level. In veterinary medicine live attenuated vaccines, inactivated vaccines and subunit vaccines are commonly used. Combination between the various vaccine types exists. In comparison live attenuated vaccines induces higher antibody titres within a shorter time period than inactivated vaccines. The immune response induced by vaccination varies between individuals, but appears not to be affected by age or sex of the vaccinated dog. Recommendations for vaccination in Sweden are 3 doses of vaccine until the dog is 1 year of age if live attenuated vaccine is used. If inactivated vaccine is used or there is a higher risk of disease 4 doses are suggested. It is recommended to revaccinate adult dogs every third year to get full protection. When revaccinated an increased level of antibodies occur in dogs with low levels of antibodies. A low antibody response might occur in presence of maternal antibodies, incorrect administration or at vaccination of immunosuppressed dogs. To prevent reactions against the vaccine, vaccination should not be performed to often even if it is important to build up antibodies in individuals that lack immunity. Benefits and risks should be considered for every dog. Without vaccination, diseases caused by canine distemper virus, canine parvovirus and canine adenovirus can reach a high prevalence and cause death. Dogs that have not been vaccinated for at least three years usually have protective antibody titres in accordance with the recommended revaccination intervals in Sweden. Efficient herd immunity reduces the impact of infection and even a dog, lacking immunity, can be protected against disease

Pandemic influenza A(H1N1)pdm09 seroprevalence in Sweden before and after the pandemic and the vaccination campaign in 2009.

The immunity to pandemic influenza A(H1N1)pdm09 in Sweden before and after the outbreaks in 2009 and 2010 was investigated in a seroepidemiological study. Serum samples were collected at four time points: during 2007 (n = 1968), in October 2009 (n = 2218), in May 2010 (n = 2638) and in May 2011 (n = 2513) and were tested for hemagglutination inhibition (HI) antibodies. In 2007, 4.9% of the population had pre-existing HI titres ≥40, with the highest prevalence (20.0%) in 15-24 year-olds, followed by ≥80 year-olds (9.3%). The overall prevalence of HI titres ≥40 had not changed significantly in October 2009. In May 2010 the prevalence had increased to 48.6% with the highest percentages in 5-14 year-olds (76.2%) andlowest in 75-79 year-olds (18.3%). One year later the prevalence of HI titres ≥40 had increased further to 52.2%. Children 5-14 years had the highest incidence of infection and vaccine uptake as well as the highest post-pandemic protective antibody levels. In contrast, the elderly had high vaccine uptake and low attack rate but low levels of protective antibodies, underlining that factors other than HI antibodies are involved in protection against influenza A(H1N1)pdm09. However, for all age-groups the seroprevalence was stable or increasing between 2010 and 2011, indicating that both vaccine- and infection-induced antibodies were long-lived

Prevalence of HI titers ≥40, pandemic vaccine uptake and laboratory-confirmed cases in Stockholm county.

<p>Influenza A(H1N1)pdm09 in Stockholm county the 2009–2010 and 2010–2011 seasons. Post-pandemic prevalence of HI titers ≥40 (samples collected in May 2010), pandemic vaccine uptake and laboratory-confirmed cases for the 2009–2010 and 2010–2011 seasons.</p

Number of tested serum samples per age-group and collection period (percent of total).

<p>Number of tested serum samples per age-group and collection period (percent of total).</p

HI titers against influenza A(H1N1)pdm09.

<p>HI titers against influenza A(H1N1)pdm09 in seropositive individuals (HI ≥10) in May 2010 and May 2011. Horizontal bars show medians, while boxes show 25th and 75th percentiles. Sera were not titrated further than 640.</p

Prevalence of HI titers ≥40 and ≥10 against influenza A(H1N1)pdm09.

<p>Percentage of individuals with HI titers (A) ≥40 and (B) ≥10 against influenza A(H1N1)pdm09 in serum samples collected in 2007, October 2009, May 2010 and May 2011. Bars indicate 95% confidence intervals.</p