Perfusion index during endotracheal intubation and extubation: A prospective observational study.

Introduction: Perfusion index (PI) can be detected using a pulse oximeter. Its value decreases in response to noxious stimuli. Here, we investigated its efficacy in detecting hemodynamic responses during endotracheal intubation and extubation. Methods: An approval from the institutional ethics committee was obtained along with a written informed consent from the patients involved in this study. A sample size of 30 was calculated. Reading of PI, heart rate, and blood pressures (systolic, diastolic, and mean arterial) were recorded at pre-intubation, post-intubation, during neuromuscular block reversal, pre-extubation and at extubation. Clinically significant heart rate, blood pressure (systolic, diastolic, and mean) and PI was defined as increase by >10 bpm, rise by ≥15 bpm and a decrease by ≥10%, respectively, from pre-intubation value. Results: Clinically significant change in PI was seen at all intervals with maximum decrease in PI occurring during neuromuscular block reversal (42.6% at the start and 56.7% at the end of neuromuscular block reversal). A negative correlation was noted between PI and the other non-invasive hemodynamic parameters. Conclusion: PI decreases on noxious stimuli and correlates negatively with the other non-invasive hemodynamic parameters. Hemodynamic response at neuromuscular block reversal is maximum.

Use of a Macintosh blade in extrahepatic portal vein obstruction with difficult intubation: two case reports.

BACKGROUND: We report the management of two patents from the Indian subcontinent with extrahepatic portal vein obstruction presenting with anticipated difficult airway. A Macintosh blade was used to secure the airway after using various instruments designed for difficult airway. To the best of our knowledge, no case has previously been reported in which a Macintosh blade was used successfully in patients with extrahepatic portal vein obstruction with a difficult airway. CASE PRESENTATION: Two women (case 1 and case 2) of South Asian ethnicity with extrahepatic portal vein obstruction presented for an elective splenorenal shunt. They both had micrognathia and restricted mouth openings. They had similar airway profiles with mouth openings of just 2 cm, Mallampati class IV, a thyromental distance <4 cm, a hyomental distance <2.5 cm, and a sternomental distance of 10 cm. Awake intubation was attempted in both patients after standard airway preparation in the form of preoperative 4 % lignocaine nebulization and 2 % viscous lignocaine gargle along with an on-table supralaryngeal nerve block using 2 % lignocaine and transtracheal infiltration with 4 % lignocaine. The patient in case 1 tolerated the procedure well whereas the patient in case 2 had to be given propofol 60 mg. Endotracheal intubation with a 6.5 mm polyvinyl chloride endotracheal tube was attempted using a Truview EVO2, an Airtraq, and a Miller blade no. 3 but was unsuccessful. Finally, a trial intubation was performed successfully with a Macintosh blade with a stubby handle assisted by a Frova Intubating Introducer in case 1 and a gum elastic bougie in case 2. CONCLUSIONS: Although many instruments have been introduced to manage difficult airways, our experience in these cases suggests that the Macintosh blade can be used first when attempting endotracheal intubation before using other instruments. Patients from the Indian subcontinent with extrahepatic portal vein obstruction are often found to have associated temporomandibular joint ankyloses (hence difficult airways). We hypothesize that a difficult intubation should be anticipated in these patients. Such an association has not been made before.