Crisis management during anaesthesia: hypertension

Perioperative Hypertension Etiologies in Patients Undergoing Noncardiac Surgery in University Health Network Hospitals–Canada from 2015–2020

Introduction

Perioperative hypertension, defined as increased blood pressure around the surgery, is a known risk factor for perioperative complications, including cardiovascular events. Identifying reasons associated with hypertension in each period is of great help in preventing and better managing perioperative hypertension.

Objective

The aim of the study was to explore common etiologies of hypertension during the perioperative period (pre, intra, and post-operation) in patients who underwent noncardiac surgeries in University Health Network (UHN) hospitals, Canada, from 2015 to 2020.

Patients and Methods

We retrospectively analyzed the medical records of 174 patients undergoing noncardiac surgeries who experienced perioperative hypertension. We assessed the prevalence of 10 reasons for perioperative hypertension as a whole and also each period separately according to the physicians’ notes in patients’ medical records. Two-way measurements ANOVA was used to determine the change of mean hypertension among patients for specific etiology.

Results

The common etiologies of perioperative hypertension were poorly controlled hypertension (21.8%), excessive fluid therapy (19.5%), excessive vasopressor (18.4%), and medication withdrawal (13.7%). Regarding each period separately, the most common reasons were poorly controlled hypertension for pre (42.9%) and intraoperative period (22.7%) and fluid overload for the postoperative period (20.1%). Poor control of hypertension showed both within-subject statistical significance for systolic and between-subject statistical significance for diastolic blood pressure.

Conclusion

Poorly controlled hypertension is the most significant etiology of perioperative hypertension in patients undergoing noncardiac surgeries. Apart from poorly controlled hypertension, as a patient-related factor, iatrogenic factors such as excessive vasopressor therapy, aggressive fluid replacement and poor management of antihypertensive medications can also cause perioperative hypertension.

Retrospective evaluation of labetalol as antihypertensive agent in dogs

Background

To evaluate the effect on arterial blood pressure (ABP) of labetalol infusion as treatment for perioperative non nociceptive acute hypertension in dogs. The clinical records of dogs receiving intra or postoperative labetalol infusion were retrospectively reviewed. Invasive systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressure and heart rate (HR) before labetalol infusion (T0) and 15, 30, 45 and 60 min (T1, T2, T3 and T4 respectively) after infusion were retrieved. The dose rate of labetalol infusion and use of concurrently administered drugs that could have potentially affected ABP and/or HR were also recorded. ANOVA for repeated measures and Dunnett’s multiple comparison test were used to determine the effect of labetalol on ABP and HR. Differences were considered significant when p < 0.05.

Results

A total of 20 dogs met the inclusion criteria, and hypertension was documented after craniotomy (12/20), adrenalectomy (4/20) and other procedures (4/20). Five dogs received labetalol intraoperatively, 14 postoperatively, and 1 during the surgical procedure and recovery. Median infusion duration and rate were 463 (60-2120) minutes and 1.1 (0.2–3.4) mg/kg/h respectively. Median loading dose was 0.2 (0.2–0.4) mg/kg. Labetalol produced a significant decrease in SAP and DAP at all time points compared to T0 (p < 0.05), while the effect was not significant at T1 for MAP (p = 0.0519). Median maximum MAP decrease was 31 (20–90) mmHg. Heart rate did not increase significantly during treatment (p = 0.2454). Acepromazine given before or during labetalol treatment did not reduce significantly ABP (p = 0.735).

Conclusions

Labetalol produced a reliable and titratable decrease in ABP with non significant increase in HR.

Hypertensive crisis caused by electrocauterization of the adrenal gland during hepatectomy

BACKGROUND

Hypertensive crisis (i.e., systolic blood pressure over 300 mmHg) is very rare during operation except pheochromocytoma, but it can be a fatal and embarrassing to surgeons and anesthesiologists. The right adrenal gland can be electrocauterized during a right hemi-hepatectomy. We report a case of hypertensive crisis during right hemi-hepatectomy in which the right adrenal gland was stimulated by monopolar electrocautery in a patient with normal neuroendocrine function.

CASE PRESENTATION

A 73-year-old man with hepatocellular carcinoma was scheduled to undergo right hemi-hepatectomy. Three hours into the surgery, the patient's blood pressure increased abruptly from 100/40 to over 350/130 mmHg (the maximum measurement pressure of the monitor; 350 mmHg). The surgeon had cauterized the right adrenal gland using monopolar electrocautery to separate the liver from the adrenal gland immediately prior to the event. Approximately 3 minutes after suspending the operation, blood pressure returned to baseline levels. After the event, the operation was successfully completed without any complication. Hormonal studies and iodine-123 meta-iodobenzylguanidine scintigraphy revealed no neuroendocrine tumor such as a pheochromocytoma.

CONCLUSION

Operations such as hepatectomy that stimulate the adrenal gland may lead to an unexpected catecholamine surge and result in hypertensive crisis, even if neuroendocrine function of the adrenal gland is normal.

Anesthetic management of hypertensive crisis in a three-year-old patient with undiagnosed severe renal artery stenosis: a case report

Pediatric hypertensive crisis is a potentially life threatening medical emergency, usually secondary to an underlying disease. Hypertension commonly occurs during general anesthesia, and is usually promptly and appropriately treated by anesthesiologists. However in children with severe, unexplained, or refractory hypertension, it has the potential to cause morbidity and even mortality in susceptible patients. We report an anesthetic management of an unexpected hypertensive crisis that developed during general anesthesia in a three-year-old girl with undiagnosed severe left renal artery stenosis.

The incidence of intraoperative hypertension and risk factors for its development during thyroid surgery

We studied the influence of demographic characteristics, comorbidity, and type and duration of surgery and anesthesia on the occurrence of intraoperative hypertension (IOHTA). Logistic regression analyses were used in order to determine the predictors of occurrence of IOHTA. More than 60% of our patients had IOHTA. Multivariate analysis showed that independent predictors for IOHTA were older age, BMI 25 kg/m(2), and hypertension as a coexisting disease. Hypertension is common during thyroid surgery, and a significant number of patients remained hypertensive during the postoperative period.

Rural Anaesthetic Audit 2006 to 2010

In order to review anaesthetic morbidity in our remote rural hospital, a retrospective audit of all anaesthetic records was undertaken for a five-year period between 2006 and 2010. Eight hundred and eighty-nine anaesthetic records were reviewed. The patients were all American Society of Anaesthesiologists physical status I to III. Ninety-eight percent of the anaesthetics were performed by general practitioner (non-specialist) anaesthetists. There were no anaesthetic deaths or serious adverse outcomes reported over this period. Sixteen intraoperative and seven postoperative problems were documented, but all were resolved uneventfully. The most common problems documented were difficult intubation (n=9) and respiratory depression (n=3). Within the limitations of this retrospective audit, these findings indicate that general practitioner anaesthetists provided safe anaesthesia in a remote rural hospital. It is our opinion that the case selection, prior experience of anaesthetic and theatre staff, stable nursing workforce and the use of protocols were important factors in determining the low rate of adverse events. However, we caution against over-interpretation of the data, given its retrospective nature, relatively small sample size, reliance on case records and the absence of agreed definitions for adverse events. We would also like to encourage all anaesthetic services, however remote, to audit their results as part of ongoing quality assurance.

Phaeochromocytoma Crisis Presenting under Anaesthesia with Profound Left Ventricular Failure — Successful Treatment with Intra-Aortic Balloon Pump

A patient presented with a phaeochromocytoma crisis during routine anaesthesia for minor ENT surgery. The ensuing cardiac arrest and profound left ventricular failure were successfully treated with an intra-aortic balloon pump until alpha blockade with phenoxybenzamine took effect. The rapid diagnosis of phaeochromocytoma and management of phaeochromocytoma crisis are reviewed.

[Hypertension and anesthesia: consensus statement of the Catalan Associations of Anesthesiology and Hypertension]

The prevalence of hypertension is high in the surgical population. Differing practices and the absence of consensus among physicians involved in caring for hypertensive patients has made it one of the most frequent reasons for cancelling scheduled surgery. The aim of this consensus statement is to outline a practical approach to managing the hypertensive surgical patient. Hypertension is associated with increased risk of perioperative complications, particularly those related to systemic effects and notable fluctuations in blood pressure during surgery. Preoperative assessment should center on a search for signs and symptoms of target organ damage. The anesthesiologist should seek to reduce perioperative fluctuations in arterial pressure, particularly guarding against sustained hypotension. After surgery, antihypertensive medication should be resumed as soon as possible.