Perioperative hypertensive crisis: newer concepts

An audit of postoperative haemodynamic stability after intraoperative labetalol administration in non-cardiac surgery patients

Anaesthesiologists commonly use intravenous labetalol to adjust patient haemodynamics during surgical procedures. Cases of profound hypotension after continuous labetalol infusions have been reported; however, there is limited evidence regarding the safety of intraoperative labetalol boluses. This audit examined the frequency of postoperative hypotension and bradycardia in 292 adult non-cardiac surgery patients treated with intraoperative labetalol boluses. Blood pressure and heart rate data were collected from the post-anaesthesia care unit and on the floor units for 24 hours after surgery. The median total intraoperative labetalol dose was 10mg. A total of 30/292 patients had all-cause postoperative hypotension within 24 hours of surgery, 26 of which had other medical or surgical precipitants. Fifteen patients developed bradycardia. There were no deaths or intensive care unit admissions attributed to labetalol. This audit demonstrates a low risk of all-cause postoperative hypotension (10%) and bradycardia (5%) after the use of small IV doses of intraoperative labetalol.

Pulse rate and blood pressure changes during low-irradiance PDT compared with conventional PDT in the treatment of facial actinic keratoses: A retrospective study

BACKGROUND

Conventional photodynamic therapy (c-PDT) is a highly effective treatment for actinic keratoses. Besides pain as the main side effect, blood pressure (BP) increases and hypertensive crises may occur during treatment. Reducing the irradiation intensity while keeping the total dose constant (low-irradiance PDT) can achieve a clinically relevant reduction in pain. This study aimed to evaluate the influence of li-PDT on the BP and pulse (PR) during therapy and the incidence of post-interventional hypertension compared with c-PDT.

METHODS

We retrospectively analyzed the treatment data of 79 patients (39 c-PDT and 40 li-PDT). BP and PR measurements were performed in all patients before PDT, at mid-exposure, and immediately after PDT. In addition, the pain was assessed by using the visual analog scale.

RESULTS

Patients treated with li-PDT reported significantly lower pain than those receiving c-PDT (p < .0005). Additionally, they showed less systolic (SBP) and diastolic (DBP) BP increase (∆SBP: p < .0005, ∆DBP: p = .015) and overall lower absolute BP values (SBP: p < .0005, DBP: p = .008) compared with c-PDT. They were also significantly less likely to develop post-interventional hypertension (p = .037) or higher stages of arterial hypertension. Regarding PR, there was no difference in absolute values between both groups, but the increase from onset to half irradiation duration was significantly higher in c-PDT (p = .013).

CONCLUSIONS

Li-PDT is an excellent option to reduce the elevation of arterial BP and decrease the incidence of post-interventional hypertension and hypertensive crisis. This finding has considerable relevance, especially with the risk profile of many PDT patients in mind (advanced age and cardiovascular history).

Perioperative angiotensin-converting enzyme inhibitors or angiotensin II type 1 receptor blockers for preventing mortality and morbidity in adults

BACKGROUND

Perioperative hypertension requires careful management. Angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II type 1 receptor blockers (ARBs) have shown efficacy in treating hypertension associated with surgery. However, there is lack of consensus about whether they can prevent mortality and morbidity.

OBJECTIVES

To systematically assess the benefits and harms of administration of ACEIs or ARBs perioperatively for the prevention of mortality and morbidity in adults (aged 18 years and above) undergoing any type of surgery under general anaesthesia.

SEARCH METHODS

We searched the current issue of the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 12), Ovid MEDLINE (1966 to 8 December 2014), EMBASE (1980 to 8 December 2014), and references of the retrieved randomized trials, meta-analyses, and systematic reviews.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing perioperative administration of ACEIs or ARBs with placebo in adults (aged 18 years and above) undergoing any type of surgery under general anaesthesia. We excluded studies in which participants underwent procedures that required local anaesthesia only, or participants who had already been on ACEIs or ARBs.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, assessed the risk of bias, and extracted data. We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included seven RCTs with a total of 571 participants in the review. Two of the seven trials involved 36 participants undergoing non-cardiac vascular surgery (infrarenal aortic surgery), and five involved 535 participants undergoing cardiac surgery, including valvular surgery, coronary artery bypass surgery, and cardiopulmonary bypass surgery. The intervention was started from 11 days to 25 minutes before surgery in six trials and during surgery in one trial. We considered all seven RCTs to carry a high risk of bias. The effects of ACEIs or ARBs on perioperative mortality and acute myocardial infarction were uncertain because the quality of the evidence was very low. The risk of death was 2.7% in the ACEIs or ARBs group and 1.6% in the placebo group (risk ratio (RR) 1.61; 95% confidence interval (CI) 0.44 to 5.85). The risk of acute myocardial infarction was 1.7% in the ACEIs or ARBs group and 3.0% in the placebo group (RR 0.55; 95% CI 0.14 to 2.26). ACEIs or ARBs may improve congestive heart failure (cardiac index) perioperatively (mean difference (MD) -0.60; 95% CI -0.70 to -0.50, very low-quality evidence). In terms of rate of complications, there was no difference in perioperative cerebrovascular complications (RR 0.48; 95% CI 0.18 to 1.28, very low-quality evidence) and hypotension (RR 1.95; 95% CI 0.86 to 4.41, very low-quality evidence). Cardiac surgery-related renal failure was not reported. ACEIs or ARBs were associated with shortened length of hospital stay (MD -0.54; 95% CI -0.93 to -0.16, P value = 0.005, very low-quality evidence). These findings should be interpreted cautiously due to likely confounding by the clinical backgrounds of the participants. ACEIs or ARBs may shorten the length of hospital stay, (MD -0.54; 95% CI -0.93 to -0.16, very low-quality evidence) Two studies reported adverse events, and there was no evidence of a difference between the ACEIs or ARBs and control groups.

AUTHORS' CONCLUSIONS

Overall, this review did not find evidence to support that perioperative ACEIs or ARBs can prevent mortality, morbidity, and complications (hypotension, perioperative cerebrovascular complications, and cardiac surgery-related renal failure). We found no evidence showing that the use of these drugs may reduce the rate of acute myocardial infarction. However, ACEIs or ARBs may increase cardiac output perioperatively. Due to the low and very low methodology quality, high risk of bias, and lack of power of the included studies, the true effect may be substantially different from the observed estimates. Perioperative (mainly elective cardiac surgery, according to included studies) initiation of ACEIs or ARBs therapy should be individualized.

Hemodynamic profiles of intubated and mechanically ventilated carbon monoxide-poisoned patients during systemic hyperbaric oxygen therapy

Background

Carbon monoxide (CO) poisoning can be a life threatening condition. Systemic hyperbaric oxygen (HBO) therapy is used to induce CO detoxification. However, little is known about the hemodynamic response to HBO in severely intoxicated patients.

Methods

We retrospectively analyzed the medical records of 6 CO-poisoned patients treated with propofol, rocuronium bromide, and HBO. The HBO protocol comprised 3 HBO treatments (HBOT1 to HBOT3) within 24 hours. During all HBO sessions heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse blood pressure (ΔBP) were measured every five minutes. Non-parametric tests were used to compare data between HBO sessions.

Results

HR increased significantly as the number of HBOT increased, from 68 beats per minute (bpm) during HBOT1 to 77 and 86 bpm during HBOT2 and HBOT3, respectively (p < 0.05). In addition, while no significant change was found for DBP, both SBP and ΔBP showed a transient and significant increase during HBOT2, compared to HBOT1, that did not return to basal values during HBOT3.

Conclusion

Based on previous studies that have established the respective effects of rocuronium bromide, propofol, HBO, and CO alone on HR, SBP, and ΔBP, it is concluded that the hemodynamic responses observed in the present study are likely to be due to CO. If such, given that neither HR nor SBP and ΔBP returned to basal values by the end of HBOT3, it is suggested that more than 3 HBOT sessions could be necessary to provide full hemodynamic recovery in CO-poisoned patients.

Cardiovascular anesthetic complications and treatment in oral surgery

Perioperative hypertension is a common problem. If hypertension is left untreated in patients at risk, infarctions and stroke are possible. There are limited choices of antihypertensive agents for the office. Aggressive antihypertensive therapy is not indicated because most of the episodes seen in the office are hypertensive urgencies and not emergencies. Hypotension is usually managed by decreasing the depth of anesthesia, intravenous fluids, and then vasopressors, typically ephedrine or phenylephrine. Consider treatment of hypotension whenever the mean arterial pressure decreases less than 60 mm Hg.

Intraoperative management of patients with incidental catecholamine producing tumors: A literature review and analysis

Context:

Present knowledge about intraoperative management, morbidity, and mortality of patients with undiagnosed catecholamine-producing tumors is mostly based on published case reports and anecdotal evidence.

Aims:

The aim was to summarize the management and outcomes of reported cases and analyze for practice patterns, deduct useful management recommendations as applicable.

Settings and Design:

The Medline database was searched with specific keywords for the period of 1988-2010 for cases of incidental pheochromocytomas and paragangliomas.

Materials and Methods:

Case reports in the English language with a postoperative diagnosis of pheochromocytoma and paraganglioma by histopathology were included. Systematic data extraction from case reports was done.

Statistical analysis used:

Descriptive statistics were applied.

Results:

Of 823 retrieved records, 62 case reports met inclusion criteria. Hemodynamic instability occurred primarily during mass manipulation/intraoperatively (52%, n = 32) and induction/laryngoscopy (18%, n = 11). In cases reporting specific antihypertensive treatments, nitrates (67%, n = 30) represented the majority of medications used, followed by beta-blockers (47%, n = 21). Alpha receptor blockers were administered in 33% (n = 15). The perioperative mortality was 8% (n = 5), and none of these patients received intraoperative alpha blockade. A catecholamine-secreting tumor was suspected intraoperatively in 26% of cases.

Conclusions:

The perioperative mortality based on the reviewed cases of incidental catecholamine producing tumors was less than would traditionally be expected. Intraoperative alpha receptor blockade to treat hypertension was reported in 33% of cases, and none of the patients with a fatal outcome had received it. A higher intraoperative index of suspicion and a lower threshold to consider alpha blocking medications for severe intraoperative hypertension may improve outcomes.

Intraoperative management of patients with incidental catecholamine producing tumors: A literature review and analysis

CONTEXT

Present knowledge about intraoperative management, morbidity, and mortality of patients with undiagnosed catecholamine-producing tumors is mostly based on published case reports and anecdotal evidence.

AIMS

The aim was to summarize the management and outcomes of reported cases and analyze for practice patterns, deduct useful management recommendations as applicable.

SETTINGS AND DESIGN

The Medline database was searched with specific keywords for the period of 1988-2010 for cases of incidental pheochromocytomas and paragangliomas.

MATERIALS AND METHODS

Case reports in the English language with a postoperative diagnosis of pheochromocytoma and paraganglioma by histopathology were included. Systematic data extraction from case reports was done.

STATISTICAL ANALYSIS USED

Descriptive statistics were applied.

RESULTS

Of 823 retrieved records, 62 case reports met inclusion criteria. Hemodynamic instability occurred primarily during mass manipulation/intraoperatively (52%, n = 32) and induction/laryngoscopy (18%, n = 11). In cases reporting specific antihypertensive treatments, nitrates (67%, n = 30) represented the majority of medications used, followed by beta-blockers (47%, n = 21). Alpha receptor blockers were administered in 33% (n = 15). The perioperative mortality was 8% (n = 5), and none of these patients received intraoperative alpha blockade. A catecholamine-secreting tumor was suspected intraoperatively in 26% of cases.

CONCLUSIONS

The perioperative mortality based on the reviewed cases of incidental catecholamine producing tumors was less than would traditionally be expected. Intraoperative alpha receptor blockade to treat hypertension was reported in 33% of cases, and none of the patients with a fatal outcome had received it. A higher intraoperative index of suspicion and a lower threshold to consider alpha blocking medications for severe intraoperative hypertension may improve outcomes.