A randomised comparative study of the effect of Airtraq optical laryngoscope vs. Macintosh laryngoscope on intraocular pressure in non-ophthalmic surgery / Estudo comparativo randomizado do efeito do laringoscópio óptico Airtraq vs. laringoscópio Macintosh sobre a pressão intraocular em cirurgia não oftálmica

BACKGROUND: We compared intraocular pressure changes following laryngoscopy and intubation with conventional Macintosh blade and Airtraq optical laryngoscope. METHODS: Ninety adult patients were randomly assigned to study group or control group. Study group (n = 45) - Airtraq laryngoscope was used for laryngoscopy. Control group (n = 45) - conventional Macintosh laryngoscope was used for laryngoscopy. Preoperative baseline intraocular pressure was measured with Schiotz tonometer. Laryngoscopy was done as per group protocol. Intraocular pressure and haemodynamic parameters were recorded just before insertion of the device and subsequently three times at an interval of one minute after insertion of the device. RESULTS: Patient characteristics, baseline haemodynamic parameters and baseline intraocular pressure were comparable in the two groups. Following insertion of the endotracheal tube with Macintosh laryngoscope, there was statistically significant rise in heart rate and intraocular pressure compared to Airtraq group. There was no significant change in MAP. Eight patients in Macintosh group had tongue-lip-dental trauma during intubation, while only 2 patients received upper airway trauma in Airtraq group. CONCLUSION: We conclude that Airtraq laryngoscope in comparison to Macintosh laryngoscope results in significantly fewer rises in intraocular pressure and clinically less marked increase in haemodynamic response to laryngoscopy and intubation.

JUSTIFICATIVA: Comparar as alterações de pressão intraocular após laringoscopia e intubação com lâmina Macintosh convencional e laringoscópio óptico Airtraq. MÉTODOS: Noventa pacientes adultos foram randomicamente designados para os grupos estudo ou controle. No grupo estudo (n = 45) o laringoscópio Airtraq foi usado para laringoscopia e no grupo controle (n = 45) o laringoscópio Macintosh convencional foi usado para laringoscopia. A pressão intraocular foi mensurada no pré-operatório com tonômetro Schiotz. A laringoscopia foi feita de acordo com o protocolo de cada grupo. Pressão intraocular e parâmetros hemodinâmicos foram registrados logo antes da inserção do dispositivo e três vezes após a inserção do dispositivo, com intervalo de um minuto. RESULTADOS: As características dos pacientes, os parâmetros hemodinâmicos basais e a PIO basal foram comparáveis nos dois grupos. Após a inserção do tubo endotraqueal com o laringoscópio Macintosh, houve um aumento estatisticamente significativo da frequência cardíaca e da pressão intraocular em comparação com o grupo Airtraq. Não houve alteração significativa da PAM. Oito pacientes do grupo Macintosh sofreram trauma de língua-lábio-dental durante a intubação, enquanto apenas dois pacientes sofreram trauma das vias aéreas superiores no grupo Airtraq. CONCLUSÃO: Concluímos que o laringoscópio Airtraq, em comparação com o laringoscópio Macintosh, resultou em elevações significativamente menores da PIO e em aumentos clinicamente menos acentuados da resposta hemodinâmica à laringoscopia e intubação.

A Comparative Study of Fentanyl and Dexmedetomidine in Attenuating Haemodynamic Response of Laryngoscopy and Intubation.

Background: Dexmedetomidine is a centrally acting alpha-2 adrenoceptor agonist. In this study, we compared dexmedetomidine to fentanyl in attenuating sympathetic response to laryngoscopy and tracheal intubation. Methods: Eighty ASA grade I-II patients requiring tracheal intubation were included in this prospective study and were randomly assigned to the dexmedetomidine (Group D) and fentanyl group (Group F) (40 patients in each group). Both the drugs were given at 1 μg/kg dose prior to laryngoscopy. We assessed heart rate, blood pressures and complications (bradycardia, hypotension and sedation). Results: The two groups were comparable in demographic parameters. The baseline mean heart rate (P=0.94) was not significantly different between Group F and Group D. Increase in heart rate after laryngoscopy and intubation was significantly lower in Group D compared to Group F (P=0.039). Mean heart rate remained lower at one minute after intubation in Group D but it was not statistically significant (94.64 s vs 86.28 sec). The difference in mean heart rate between two groups was comparable at three, five, ten and fifteen minutes after intubation. The baseline Mean arterial pressure was comparable between the groups (P=0.83) and remained similar throughout 15 minutes after intubation. Group D showed significant hypotension compared to Group F (P=0.03), whereas there was no significant bradycardia between these groups (P=0.19). Mean sedation score is higher in Group D compared to Group F. Conclusion: At 1 μg/kg dose, both dexmedetomidine and fentanyl cause partial attenuation of sympathetic response to laryngoscopy and intubation but dexmedetomidine blunts this response more effectively than fentanyl.