Impact of clonidine administration on delirium and related respiratory weaning after surgical correction of acute type-A aortic dissection: results of a pilot study

Abstract

Delirium and transient neurologic dysfunctions (TND) often complicate the postoperative course after surgery for acute type-A aortic dissection (AAD). We evaluated the role of clonidine on neurological outcome and respiratory function in 30 consecutive patients undergoing surgery for AAD. Patients were prospectively randomized to receive either clonidine (0.5 microg/kg bolus, followed by continuous infusion at 1-2 microg/kg/h) or placebo (NaCl 0.9%) in on starting and throughout the weaning period from the mechanical ventilation. Incidence of delirium and TND, Delirium Detection Score (DDS), weaning parameters [respiratory rate to tidal volume ratio - f/VT; pressure-frequency product (PFP); partial pressure of arterial oxygen to fractional inspired oxygen concentration (PaO(2)/FiO(2)); partial pressure of carbon dioxide (PaCO(2))], weaning duration and intensive care unit (ICU) length of stay were recorded. The two groups were similar for preoperative and operative variables and also for the incidence of postoperative complications. DDS was lower in the clonidine group (P<0.001). Patients weaned with clonidine showed lower f/VT and PFP, higher PaO(2)/FiO(2) and PaCO(2), lower DDS, weaning period and the related ICU length of stay (P<0.001). This was further confirmed in patients developing delirium/TND. Intravenous clonidine after surgery for AAD reduces the severity of delirium, improves the respiratory function, shortens the weaning duration and the ICU length of stay.

Randomized ICU Trials Do Not Demonstrate an Association Between Interventions That Reduce Delirium Duration and Short-Term Mortality

“…Mortality was reported at hospital discharge for six studies (34, 36, 40, 44, 45, 50), and at post-study randomization day 21 in two studies (35, 47), day 28 in three studies (37, 39, 48), day 30 in three studies (42, 46, 49) or day 45 in one study (43). Short-term mortality was not able to be determined from authors for two studies (38, 40). Most of the studies (n=14) had a low Cochrane risk of bias (34–39, 42, 44–50).…”

“…Of these, four evaluated antipsychotic therapy (34–37); one evaluated IV clonidine (38); six evaluated dexmedetomidine (39–44); two evaluated rivastigmine (45, 46); two evaluated daily sedative interruption (47, 50); one evaluated early mobilization after daily sedation interruption (48); and one evaluated the maintenance of a high peri-operative perfusion pressure (49). …”

“…Delirium was evaluated either by a member of the study’s research team using the CAM-ICU (35, 37, 39, 43, 46–48); by bedside clinicians using either the CAM-ICU (42, 44, 45) or the ICDSC (34, 41, 50); by a psychiatrist using DSM-IV criteria (38, 40, 47) or the bedside clinician using the ICDSC with confirmation by a psychiatrist using DSM-IV criteria (36). Duration of delirium was either not collected during the study or was not retrievable from two studies (43, 49).…”

“…The studies enrolled either a mixed-medical-surgical population (n=8) (34, 35, 39, 41–43, 46, 50); a surgical population (n=7) (36–38, 40, 45, 49); or a medical population (n=2) (47, 48). Most (n=13) of the studies enrolled only patients who were intubated (35, 38–45, 47–50) . The average patient age was older than 50 years across all intervention and control groups in all 17 studies.…”

Sedation of mechanically ventilated adults in intensive care unit: a network meta-analysis

“…Twenty-seven articles were excluded because 20 investigated sedation protocol that the type of sedative drugs could not be identified, 4 studies were secondary analysis of previous reports, and 3 were study protocols. As a result, a total of 51 citations comprising 52 RCTs were included in our analysis141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364. The article by Jakob and colleagues comprised two RCTs38.…”