Phenylephrine in concentrations of either 2.5% or 10% is widely used as a mydriatic agent in ophthalmic surgery. Its potential cardiovascular effects are seldom recorded as ophthalmic surgery is not usually monitored by an anaesthetist. A prospective randomised double blind study was carried out in 89 consecutive cases of uncomplicated cataract surgery in the presence of an anaesthesiologist ensuring the continuous monitoring of blood pressure, heart rate, electrocardiography and pulse oximetry. All these patients were given a drop of either normal saline, 2.5% or 10% phenylephrine in addition to mydriacyl prior to surgery. Blood pressure readings were found to be significantly higher in non-hypertensive patients receiving phenylephrine at the start of the operation and at five, 10, 15 and 20 minutes intra-operatively and the first three hours post-operatively. Blood pressure readings in hypertensive patients, on the other hand, were also found to increase after phenylephrine administration, though not statistically significant. 10.3% of the 10% phenylephrine group and 3% of the 2.5% phenylephrine group required intraoperative intravenous hypotensive agent to control the blood pressure. There were no arrhythmias or ischaemic changes observed intraoperatively. None of the patients complained of palpitation, headache or chest discomfort. There was no oxygen desaturation observed. We concluded that significant hypertensive effects can arise after phenylephrine eye drop administration. Hence, it should be used cautiously with intraoperative monitoring of the cardiovascular status during cataract surgery.
Three millilitres of plain 0.5% bupivacaine were injected intrathecally at two different spinal interspaces (L2/3 and L4/5) and at two different speeds (15 and 30 sec) in four groups of ten patients. Injection at L2/3 over 15 sec produced a significantly higher mean maximum spread of analgesia (T6.4) when compared to injection at L4-5 over 15 sec (T10.3) (P < 0.05). Over the same interspace L2/3, injection over 15 sec also produced a higher level of spread as compared to the 30 sec group (p < 0.05). At 15 min there was a greater fall in blood pressure in the L2/3 15 sec group when compared to the other groups (p < 0.01). There was a further decrease in the blood pressure in L2/3 15 sec and L4/5 30 sec groups after 30 minutes of blockade (p < 0.01). Therefore close monitoring of cardiovascular parameters must be continued for at least 30 min in spinal anaesthesia with bupivacaine.
Diabetes mellitus in Asia accounts for more than half of the global prevalence. There is a high prevalence of cardiovascular disease (CVD) in the region among people with type 2 diabetes mellitus (T2DM) and it is often associated with multiple risk factors including hypertension, renal disease and obesity. The early onset of T2DM and the eventual long disease duration portends an increasing proportion of the population to premature CVD. In addition to lowering blood glucose, sodium-glucose co-transporter-2 (SGLT-2) inhibitors exert favourable effects on multiple risk factors (including blood pressure, body weight and renal function) and provide an opportunity to reduce the risk of CVD in patients with T2DM. In this article, we consolidated the existing literature on SGLT-2 inhibitor use in Asian patients with T2DM and established contemporary guidance for clinicians. We extensively reviewed recommendations from international and regional guidelines, published data from clinical trials in the Asian population (dapagliflozin, canagliflozin, empagliflozin, ipragliflozin, luseogliflozin and tofogliflozin), CVD outcomes trials (EMPAREG-OUTCOME, CANVAS and DECLARE-TIMI 58) and real-world evidence studies (CVD-REAL, EASEL, CVD-REAL 2 and OBSERVE-4D). A series of clinical recommendations on the use of SGLT-2 inhibitors in Asian patients with T2DM was deliberated among experts with multiple rounds of review and voting. Based on the available evidence, we conclude that SGLT-2 inhibitors represent an evidence-based therapeutic option for the primary prevention of heart failure hospitalization and secondary prevention of CVD in patients with T2DM, and should be considered early on in the treatment algorithm for patients with multiple risk factors, or those with established CVD.