Cough reflex sensitivity after elective Caesarean section under spinal anaesthesia and after vaginal delivery.
BACKGROUND
In pregnancy, airway oedema and heartburn may increase cough sensitivity, whereas spinal anaesthesia (SA) with local anaesthetics and opiates may decrease it. Decreased cough sensitivity increases the risk for pneumonia or retained secretions. The aim of this study was to determine whether cough sensitivity is increased in pregnant patients and if it is decreased after planned Caesarean section (CS) under SA.


METHODS
Twenty-seven non-pregnant volunteers, 27 patients after vaginal delivery (VD group), and 28 patients after CS under SA (CS group) were studied. For SA, hyperbaric bupivacaine 8-12 mg, sufentanil 5 microg, and morphine 100 microg was given. Increasing concentrations of nebulized citric acid were delivered until eliciting cough. The concentration eliciting one (C1) and two coughs (C2) were recorded and log transformed for analysis (log C1 and log C2).


RESULTS
Median (inter-quartile) log C1 was 1.3 (0.6) mg ml(-1) in the VD group, 1.6 (0.6) mg ml(-1) in the non-pregnant group (P < 0.01 vs VD group), and 2.2 (0.7) mg ml(-1) in the CS group (P < 0.0001 and P < 0.01 vs VD and non-pregnant groups, respectively). Similar results were observed with log C2. In CS group, log C1 and log C2 remained increased up to 4 h after SA.


CONCLUSIONS
Cough sensitivity was increased after VD but decreased for up to 4 h after SA.
Gayat
E
E
Département d'Anesthésie-Réanimation Chirurgicale, Assistance Publique-Hôpitaux de Paris, Hôpital Bichat-Claude Bernard, 46 rue Henri Huchard, 75018 Paris, France.
Lecarpentier
E
E
Retout
S
S
Bedairia
E
E
Batallan
A
A
Bonay
M
M
Mantz
J
J
Montravers
P
P
Desmonts
J M
JM
Guglielminotti
J
J
D000293:Adolescent; D000328:Adult; D000762:Anesthesia Recovery Period; D000773:Anesthesia, Obstetrical / Q000379:methods*; D000775:Anesthesia, Spinal; D002585:Cesarean Section; D019343:Citric Acid; D003371:Cough / Q000139:chemically induced / Q000503:physiopathology*; D036861:Delivery, Obstetric / Q000379:methods; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D011184:Postoperative Period; D049590:Postpartum Period / Q000502:physiology; D011247:Pregnancy / Q000502:physiology*; D011446:Prospective Studies; D012018:Reflex / Q000187:drug effects
D019343:Citric Acid