Response to comments on 'Hypertension and tachycardia following high spinal anaesthesia during LSCS: An unusual presentation'.

Abstract

Dear Editor, We read with interest the comments[1] to our published article,[2] and we would like to address the queries raised on a point-to-point basis. With regard to the timeline of events during the episode of hypotension, we would like to reiterate that, as mentioned in the article,[2] the blood pressure (BP) of the patient fell to 78/40 mmHg immediately after the administration of the subarachnoid block, and that following this vasopressors and intravenous (IV) fluids were given. After one minute, her BP had improved. However, after five minutes of our having administered the subarachnoid block, she complained of breathlessness. Closed breathing circuits have myriad advantages, such as providing a constant and higher fraction of inspired oxygen (FiO2), removing carbon dioxide from the expired gases, and offering lesser resistance when compared to an endotracheal tube. The work of breathing may increase when the adjustable pressure-limiting (APL) valve is partially or fully closed, providing an obstacle to the egress of gases, or when the set flow is not enough to meet the patient’s peak inspiratory flows.[3] However, the APL valve was kept open when applying the closed circuit on our patient, and a flow of 15 L/min was ensured, thereby thwarting any possibility of increased work of breathing. Our patient presented with breathlessness stemming from hypoventilation, which was more a cause rather than a symptom of probable hypercarbia. She exhibited mild agitation at that time but did not appear confused or flushed. We were unable to corroborate our clinical findings with a blood gas, as stabilizing the mother and baby took precedence over the former. However, the tidal volume and end-tidal capnography were suggestive of hypoventilation and resultant hypercarbia. We again reiterate that, as mentioned in our article,[2] other possible causes of hypertension, such as distended urinary bladder, patient anxiety, inappropriately sized non-invasive BP cuff, and pre-existing hypertensive disorders, were ruled out. Informed consent The patient has given informed consent. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.