Inhaled nitric oxide does not alter pulmonary or cardiac effects of fat embolism in dogs after cemented arthroplasty

Abstract

Inhaled nitric oxide does not alter pulmonary or cardiac effects of fat embolism in dogs after cemented arthroplasty Purpose: We examined the effect of inhaled nitric oxide (NO) on the acute pulmonary hypertension and right ventricular (RV) dilation after fat embolism. Methods: A bilateral cemented arthroplasty (BCA), created fat embolism in 20 dogs. In Part A, 12 dogs were randomized to an NO group (n = 6, inhaled NO 40 ppm before BCA and throughout the study) or a control group (n =6). In Part B, a third group of dogs (n=8) were given NO 20-40 ppm 2-3 min after BCA when pulmonary artery pressure (PAP) increased. Transesophageal echocardiography (TEE) and invasive hemodynamic monitoring evaluated the hemodynamic response to BCA. Postmortem, quantitative morphometry was used to estimate the number of fat emboli and diameter of lung vessel occluded by fat. Results: Part A: The increase in PAP in the NO group (I 6 -+ I to 34 _+ 9 mmHg) within three minutes of BCA was not different from that in the control group ( 14 _+ 4 to 35 +-9 mmHg). W~hin three minutes of BCA, TEE demonstrated RV dilation in all groups (P ~ 0.05) but there was no difference in the change in RV area in the NO and control groups. When NO was given after BCA, no difference in PAP or RV dilation was noted from that in the control group. There were no differences, at post mortem, between the groups in the diameter of lung vessel occluded by fat Conclusion: Whether given before the embolic insult or two to three minutes after the onset of pulmonary hypertension, inhaled NO did not attenuate the acute pulmonary hypertension or RV dilation after cemented arthroplasty.

Reversible Catastrophic Fat Embolism: A Case Report

“…What allowed such rapid resolution of her symptoms without clinical sequelae is unclear. In dogs, intravascular fat has been shown to move through the pulmonary vasculature over the first 3 h after bilateral cemented arthroplasty [10]. Consistent with this theory is that fat has been noted to occur in the cerebral circulation during cementing of total hip arthroplasty [11].…”

“…Nitroglycerin is known to convert to nitric oxide (NO), leading to vasodilatation [13]. Byrick et al [10] has suggested that the vasoconstriction and inflammatory changes occurring in the later phase of FES may be suppressed by NO. Fahmy et al [14] has shown improvement in elevated PAP occurring during orthopedic procedures with the use of inhaled nitric oxide.…”

Pulmonary vasodilation in acute pulmonary embolism – a systematic review

“…65,76,77 One study using fat-emboli in a canine model did, however, not detect any effects on pulmonary or cardiac function. 78 Due to the rationale of inhaled administration, only one study noticed effect on the systemic vasculature with decreased mean arterial pressure (MAP). 68 Some studies investigated dose-response relationship without consistent results, 67,68 suggesting low-dose treatment to be favorable.…”