Retrograde intubation in patients undergoing open heart surgery

Cardiovascular changes during difficult intubation were studied in 25 patients undergoing open heart surgery. The study was divided into two phases. Phase A from the first laryngoscopy to the fourth unsuccessful one; Phase B from a stabilization period until after retrograde intubation was performed. During phase A, heart rate (HR) increased significantly from 75 ± 6.5 beatslmin before laryngoscopy to 95 ± 8.5 (p < 0.05) after the last laryn-goscopy. Mean arterial pressure (MAP) also increased from 82.5 ± 4.75 mmHgto 105 ± 5.15 (p<0.005) after the last laryngoscopy. Cardiac index (CI) decreased from 2.9 ± 0.3 L·min^-1m^-2 before to 2.55 ± 0.2 after the last laryngoscopy. Pulmonary capillary wedge pressure (PCWP) increased from 10.5 ± 1 mmHg before to 19.25 ± 1.5 (p< 0.01) after the last laryngoscopy. No statistically significant changes in HR, MAP, CI, and PCWP occurred before and after intubation during Phase B. Three patients had elevated ST segments during Phase A which responded to IV nitroglycerin and propranolol. None was detected during Phase B. There were more lacerated lips and teeth damaged during Phase A. One patient developed a small peritracheal haematoma after the retrograde intubation, for which no treatment was required. This technique is safe and produces minimal cardiovascular changes for difficult intubation in patients undergoing open heart surgery.