A hemodynamic monitoring instrument comprising: a processor arranged to receive a physiological parameter indicative of heart rate and a physiological parameter indicative of arterial blood pressure and configured to compute a hemodynamic parameter correlating with systemic vascular resistance based on the received physiological parameter indicative of heart rate and the received physiological parameter indicative of arterial blood pressure; and an output device including least one of (i) a display configured to display the computed hemodynamic parameter and (ii) an alarm (32, 34) configured to generate a perceptible signal responsive to the computed hemodynamic parameter satisfying an alarm criterion, characterized in that the processor is configured to compute the hemodynamic parameter correlating with SVR based on: a first fuzzy membership function indicative of whether a heart rate indicated by the physiological parameter indicative of heart rate is slightly high or high; a second fuzzy membership function indicative of whether an arterial blood pressure indicated by the physiological parameter indicative of arterial blood pressure is low; and a third fuzzy membership function indicative of whether the arterial blood pressure indicated by the physiological parameter indicative of arterial blood pressure is very low, wherein the processor is further configured to compute the hemodynamic parameter correlating with SVR based on: a first term defined by conjunctive combination of the first fuzzy membership function and the second fuzzy membership function, and a second term corresponding to the third fuzzy membership function, the hemodynamic parameter quantifying the heuristic "ABP is low AND HR is slightly high or high" OR "ABP is very low" where APB denotes an arterial blood pressure indicated by the physiological parameter indicative of arterial blood pressure and HR denotes a heart rate indicated by the physiological parameter indicative of heart rate. a processor arranged to receive a physiological parameter indicative of heart rate and a physiological parameter indicative of arterial blood pressure and configured to compute a hemodynamic parameter correlating with systemic vascular resistance based on the received physiological parameter indicative of heart rate and the received physiological parameter indicative of arterial blood pressure; and an output device including least one of (i) a display configured to display the computed hemodynamic parameter and (ii) an alarm (32, 34) configured to generate a perceptible signal responsive to the computed hemodynamic parameter satisfying an alarm criterion, characterized in that the processor is configured to compute the hemodynamic parameter correlating with SVR based on: a first fuzzy membership function indicative of whether a heart rate indicated by the physiological parameter indicative of heart rate is slightly high or high; a second fuzzy membership function indicative of whether an arterial blood pressure indicated by the physiological parameter indicative of arterial blood pressure is low; and a third fuzzy membership function indicative of whether the arterial blood pressure indicated by the physiological parameter indicative of arterial blood pressure is very low, wherein the processor is further configured to compute the hemodynamic parameter correlating with SVR based on: a first term defined by conjunctive combination of the first fuzzy membership function and the second fuzzy membership function, and a second term corresponding to the third fuzzy membership function, the hemodynamic parameter quantifying the heuristic "ABP is low AND HR is slightly high or high" OR "ABP is very low" where APB denotes an arterial blood pressure indicated by the physiological parameter indicative of arterial blood pressure and HR denotes a heart rate indicated by the physiological parameter indicative of heart rate. a first fuzzy membership function indicative of whether a heart rate indicated by the physiological parameter indicative of heart rate is slightly high or high; a second fuzzy membership function indicative of whether an arterial blood pressure indicated by the physiological parameter indicative of arterial blood pressure is low; and a third fuzzy membership function indicative of whether the arterial blood pressure indicated by the physiological parameter indicative of arterial blood pressure is very low, wherein the processor is further configured to compute the hemodynamic parameter correlating with SVR based on: a first term defined by conjunctive combination of the first fuzzy membership function and the second fuzzy membership function, and a second term corresponding to the third fuzzy membership function, the hemodynamic parameter quantifying the heuristic "ABP is low AND HR is slightly high or high" OR "ABP is very low" where APB denotes an arterial blood pressure indicated by the physiological parameter indicative of arterial blood pressure and HR denotes a heart rate indicated by the physiological parameter indicative of heart rate. a first term defined by conjunctive combination of the first fuzzy membership function and the second fuzzy membership function, and a second term corresponding to the third fuzzy membership function, the hemodynamic parameter quantifying the heuristic "ABP is low AND HR is slightly high or high" OR "ABP is very low" where APB denotes an arterial blood pressure indicated by the physiological parameter indicative of arterial blood pressure and HR denotes a heart rate indicated by the physiological parameter indicative of heart rate.